Bacteria

Mol Gen Genet, 1998 Jan, 257(2), 113 - 23
patufet, the gene encoding the Drosophila melanogaster homologue of selenophosphate synthetase, is involved in imaginal disc morphogenesis; Alsina B et al.; Proliferation in imaginal discs requires cell growth and is linked to patterning processes controlled by secreted cell-signalling molecules . To identify new genes involved in the control of cell proliferation we have screened a collection of P-lacW insertion mutants that result in lethality in the larval/pupal stages, and characterized a novel gene, patufet (ptuf) . Inactivation of ptuf by a P element insertion in the 5' untranslated region leads to aberrant imaginal disc morphology characterized by a reduction in mass of discs and disorganization of disc cells where no folding or patterning can be detected . Moreover, apoptotic cells can be observed in these small and abnormal mutant discs . To examine the role of ptuf we have studied its clonal behaviour in genetic mosaics generated by mitotic recombination . The mutation causes reduced cell viability, smaller cell size and stops vein differentiation . Non-autonomous effects, such as abnormal differentiation of wild-type cells surrounding the clones, are also observed . We have cloned the ptuf gene of Drosophila melanogaster and found that it encodes a selenophosphate synthetase, which is the first identified in insects . Mutant flies transformed with the full-length cDNA show complete reversion of lethality and disc phenotype . Northern blot analysis and in situ hybridization indicate that the ptuf gene is expressed in imaginal discs as well as at different stages of development . The synthesis of selenoproteins by the selenophosphate synthetase, the role of selenoproteins in the maintenance of the oxidant/antioxidant balance of the cell and its possible implications in imaginal disc morphogenesis are discussed.

FEBS Lett, 1998 Jan 30, 422(2), 231 - 4
The cytochrome subunit structure in the photosynthetic reaction center of Chromatium minutissimum; Chamorovsky SK et al.; Gel-electrophoretic assay revealed that the photosynthetic reaction center (RC) of Chromatium minutissimum, in contrast to the well-known RC Rhodopseudomonas viridis, consists of five rather than four subunits with molecular masses of 37, 34, 25, 19, and 17 kDa . The 37- and 19-kDa subunits are stained with tetramethylbenzidine for the cytochrome c hemes . Absorption spectra show that the concentration of reduced cytochromes in the C . minutissimum RC poised at redox potential of -150 mV (fully reduced pool of hemes) is about three times more than in the C . minutissimum RC poised at redox potential of +260 mV (only high-potential hemes are reduced) . The results of redox titration of absorption changes at the cytochrome c alpha-band are most appropriately approximated by a six-component theoretical curve with the midpoint potentials of Em1 = 390 mV, Em2 = 320 mV, Em3 = 210 mV, Em4 = 100 mV, Em5 = 20 mV, and Em6 = -50 mV . Possible functions of the cytochromes with the midpoint potentials 210 and 100 mV, which have not been found in purple bacteria before, are discussed.

Mol Microbiol, 1998 Feb, 27(3), 661 - 7
The requirement for DsbA in pullulanase secretion is independent of disulphide bond formation in the enzyme; Sauvonnet N et al.; Results from previous studies have suggested that an intramolecular disulphide bond in the exoprotein pullulanase is needed for its recognition and transport across the outer membrane . This interpretation of the data is shown here to be incorrect: pullulanase devoid of all potential disulphide bonds is secreted with apparently the same efficiency as the wild-type protein . Furthermore, the periplasmic disulphide bond, oxidoreductase DsbA, previously shown to catalyse the formation of a disulphide bond in pullulanase and to decrease its transit time in the periplasm, is shown here to be required for the rapid secretion of pullulanase devoid of disulphide bonds . Several possible explanations for the role of DsbA in pullulanase secretion are discussed.

Dev Biol, 1998 Jan 15, 193(2), 115 - 26
A molecular analysis of hyalin--a substrate for cell adhesion in the hyaline layer of the sea urchin embryo; Wessel GM et al.; The hyaline layer of echinoderm embryos is an extraembryonic matrix that functions as a substrate for cell adhesion through early development . The major constituent of the hyaline layer is the protein hyalin, a fibrillar glycoprotein of approximately 330 kDa that multimerizes in the presence of calcium . Here we provide a molecular characterization of hyalin and identify a region of the protein that is important for its function in cell adhesion . Partial hyalin cDNAs were identified from two sea urchin species, Strongylocentrotus purpuratus and Lytechinus variegatus, by screening expression libraries with monoclonal antibodies to hyalin . The cDNAs each encode a tandemly arranged series of conserved repeats averaging 84 amino acids . These hyalin repeats are as similar between the two species as they are to repeats within each species, suggesting a strong functional conservation . Analysis of this repeat shows that it is a unique sequence within the GenBank database with only weak similarity to mucoid protein sequences . The hyalin mRNA is approximately 12 kb in length and is present in developing oocytes coincident with the appearance of cortical granules, the vesicle in which the hyalin protein is specifically packaged . The mRNA is present throughout oogenesis but is rapidly lost at oocyte maturation so that eggs and early embryos have no detectable hyalin mRNA . The hyalin protein, however, remains at relatively constant levels throughout development . Thus, all the hyalin protein present during early development, when no RNA is detectable, is maternally derived and exocytosed from cortical granules at fertilization . Hyalin mRNA reaccumulates in embryos beginning at the mesenchyme blastula stage; a RNA gel blot and in situ hybridization analysis of gastrulae and larvae shows a progressive confinement of hyalin mRNA to the aboral ectoderm . Recombinant hyalin containing the tandem repeat region of the protein was expressed in bacteria and is shown to serve as an adhesive substrate, almost equal to that of native hyalin, in cell adhesion assays . This adhesive activity is partially blocked by dilute hyalin monoclonal antibody Tg-HYL to the same extent as that for native hyalin . Thus, this hyalin repeat region appears to contain the ligand for the hyalin cell surface receptor . These data help explain some of the classic functions ascribed to the hyalin protein in early development and now enable investigators to focus on the mechanisms of cell interactions with the hyaline layer .

Blood, 1998 Feb 15, 91(4), 1438 - 45
Effects of increased anionic charge in the beta-globin chain on assembly of hemoglobin in vitro; Adachi K et al.; Studies on assembly in vitro of alpha-globin chains with recombinant beta16 Gly-->Asp, beta95 Lys-->Glu, beta120 Lys-->Glu and beta16 Gly-->Asp, 120 Lys-->Glu human beta-globin chain variants in addition to human betaA- and betaS-globin chains were performed to evaluate effects of increased anionic charge in the beta chain on hemoglobin assembly using soluble recombinant beta-globin chains expressed in bacteria . A beta112 Cys-->Asp change was also engineered to monitor effects on assembly of increased negative charge at alpha1beta1 interaction sites . Order of tetramer formation in vitro under limiting alpha-globin chain conditions showed Hb betaG16D, K120E = Hb betaK120E = Hb betaK95E > Hb betaG16D > Hb A > Hb S >>> Hb betaC112D . In addition, beta112 Cys-->Asp chains exist as monomers rather than beta4 tetramers in the absence of alpha chains, and the beta chain in Hb betaC112D tetramers was readily exchanged by addition of betas . These results suggest that affinity between alpha and beta chains is promoted by negatively-charged beta chains up to a maximum of two additional net negative charges and is independent of location on the surface except at the alpha1beta1 interaction site . In addition, our findings show that beta112 Cys on the G helix is critical for facilitating formation of stable alphabeta dimers, which then form functional hemoglobin tetramers, and that beta112 Cys-->Asp inhibits formation of stable alpha1beta1 and beta1beta2 interactions in alpha2beta2 and beta4 tetramers, respectively.

J Mol Evol, 1998 Jan, 46(1), 84 - 101
Evolution of substrate specificities in the P-type ATPase superfamily; Axelsen KB et al.; P-type ATPases make up a large superfamily of ATP-driven pumps involved in the transmembrane transport of charged substrates . We have performed an analysis of conserved core sequences in 159 P-type ATPases . The various ATPases group together in five major branches according to substrate specificity, and not according to the evolutionary relationship of the parental species, indicating that invention of new substrate specificities is accompanied by abrupt changes in the rate of sequence evolution . A hitherto-unrecognized family of P-type ATPases has been identified that is expected to be represented in all the major phyla of eukarya.

Mol Cell Biol, 1998 Mar, 18(3), 1163 - 71
Functional relationships of Srb10-Srb11 kinase, carboxy-terminal domain kinase CTDK-I, and transcriptional corepressor Ssn6-Tup1; Kuchin S et al.; The Srb10-Srb11 protein kinase of Saccharomyces cerevisiae is a cyclin-dependent kinase (cdk)-cyclin pair which has been found associated with the carboxy-terminal domain (CTD) of RNA polymerase II holoenzyme forms . Previous genetic findings implicated the Srb10-Srb11 kinase in transcriptional repression . Here we use synthetic promoters and LexA fusion proteins to test the requirement for Srb10-Srb11 in repression by Ssn6-Tup1, a global corepressor . We show that srb10delta and srb11delta mutations reduce repression by DNA-bound LexA-Ssn6 and LexA-Tup1 . A point mutation in a conserved subdomain of the kinase similarly reduced repression, indicating that the catalytic activity is required . These findings establish a functional link between Ssn6-Tup1 and the Srb10-Srb11 kinase in vivo . We also explored the relationship between Srb10-Srb11 and CTD kinase I (CTDK-I), another member of the cdk-cyclin family that has been implicated in CTD phosphorylation . We show that mutation of CTK1, encoding the cdk subunit, causes defects in transcriptional repression by LexA-Tup1 and in transcriptional activation . Analysis of the mutant phenotypes and the genetic interactions of srb10delta and ctk1A suggests that the two kinases have related but distinct roles in transcriptional control . These genetic findings, together with previous biochemical evidence, suggest that one mechanism of repression by Ssn6-Tup1 involves functional interaction with RNA polymerase II holoenzyme.

Infect Immun, 1998 Mar, 66(3), 1261 - 4
Identification of epitopes of fibronectin attachment protein (FAP-A) of Mycobacterium avium which stimulate strong T-cell responses in mice; Holsti MA et al.; The T-cell response to fibronectin attachment protein (FAP-A) in BALB/c and B10.BR mice was examined . Both strains developed strong T-cell responses to FAP-A, directed to single, unique epitopes . T cells from mice infected with Mycobacterium avium responded to FAP-A, suggesting a possible role in a protective immune response.

Infect Immun, 1998 Mar, 66(3), 1023 - 7
Evidence for specific secretion rather than autolysis in the release of some Helicobacter pylori proteins; Vanet A et al.; We investigated whether Helicobacter pylori cells actively secrete proteins such as the urease subunits UreA and UreB and the GroES and GroEL homologs HspA and HspB or whether these proteins were present in the extracellular compartment as a consequence of autolysis . Using a subcellular fractionation approach associated with quantitative Western blot analyses, we showed that the supernatant protein profiles were very different from those of the cell pellets, even for bacteria harvested in the late growth phase; this suggests that the release process is selective . A typical cytoplasmic protein, a beta-galactosidase homolog, was found exclusively associated with the pellet of whole-cell extracts, and no traces were found in the supernatant . In contrast, UreA, UreB, HspA, and HspB were mostly found in the pellet but significant amounts were also present in the supernatant . HspA and UreB were released into the supernatant at the same rate throughout the growth phase (3%), whereas large portions of HspB and UreA were released during the stationary phase (over 30 and 20%, respectively) rather than during the early growth phase (20% and 6, respectively) . The profiles of protein obtained after water extraction of the bacteria with those of the proteins naturally released within the liquid culture supernatants demonstrated that water extraction led to the release of a large amount of protein due to artifactual lysis . Our data support the conclusion that a specific and selective mechanism(s) is involved in the secretion of some H . pylori antigens . A programmed autolysis process does not seem to make a major contribution.

J Endod, 1998 Jan, 24(1), 11 - 4
Recontamination of coronally unsealed root canals medicated with camphorated paramonochlorophenol or calcium hydroxide pastes after saliva challenge; Siqueira Junior JF et al.; This in vitro study evaluated the ability of some medications to prevent recontamination of coronally unsealed root canals by bacteria from saliva . The medications tested were camphorated paramonochlorophenol (CPMC) applied in cotton pellets in the pulp chamber; calcium hydroxide/saline solution paste filling the root canal; and calcium hydroxide/CPMC/glycerin paste also filling the root canal . Medicated canals were exposed to saliva, and the number of days required for total recontamination to occur was recorded . Canals medicated with CPMC in cotton pellets were thoroughly recontaminated within an average of 6.9 days . Canals filled with calcium hydroxide/saline solution and calcium hydroxide/CPMC/glycerin showed entire recontamination within an average of 14.7 and 16.5 days, respectively . Calcium hydroxide pastes were significantly more effective than CPMC (p < 0.05).

East Afr Med J, 1997 Aug, 74(8), 519 - 22
Socio-biological status of Nigerian males with primary and secondary infertility; Alemnji GA et al.; Husbands in 100 consecutive couples complaining of lack of pregnancy after one year of normal intercourse were engaged in this study . Information from a structured questionnaire administered to these 100 men showed that 46% had primary infertility (had never impregnated any woman) and 54% secondary infertility (had in the past impregnated at least one woman irrespective of the outcome of the pregnancy) . The mean ages (years) and standard error of mean for the primary and secondary infertile groups were 33.46 +/- 1.45 and 39.28 +/- 1.41 respectively . The difference was statistically significant (p < 0.05) . Semen culture for growth of bacteria was positive in 59.3% of subjects with secondary infertility as opposed to 40.7% for primary infertility . The difference was, again, statistically significant (p < 0.05) . These findings indicate that a higher proportion of husbands in infertile couples in a group of this environment had secondary infertility, were older and were more likely to harbour infections in their semen than those with primary infertility . Hence there should be a greater awareness of the significant involvement of bacterial infection of the genital tract of infertile Nigerian subjects than and before this factor should be taken into account in the prevention and treatment strategies for infertility in this and presumably other tropical countries.

FEMS Microbiol Lett, 1998 Feb 1, 159(1), 137 - 44
Macrorestriction analysis of Desulfurella acetivorans and Desulfurella multipotens; Pradella S et al.; The genomes of the phylogenetically and physiologically unique bacteria Desulfurella acetivorans DSM 5264T and D . multipotens DSM 8415T were characterized and compared by pulsed field gel electrophoresis (PFGE) . Macrorestriction patterns made of large PFGE separated DNA fragments were generated by digesting the genomic DNAs of both strains with the rare cutting restriction endonucleases ApaI, AscI, EagI, RsrII, SacII, SalI as well as with the intron encoded endonuclease I-CeuI . The sum of calculated fragment sizes from digests of the first six enzymes yielded estimates for the chromosome sizes of D . acetivorans with a mean of 1939.0 +/- 26.0 kb and for D . multipotens with a mean of 1864.0 +/- 23.0 kb . Within the patterns obtained from EagI and RsrII cleavages the apparent differences could be attributed to DNA insertion or deletion and to point mutation . The single, circular chromosomes of the two strains contain two copies of 23S rRNA genes each . Different extrachromosomal elements were detected in both strains.

Mol Microbiol, 1998 Jan, 27(2), 323 - 36
Evidence for pore-forming ability by Legionella pneumophila; Kirby JE et al.; Legionella pneumophila is the cause of Legionnaires' pneumonia . After Internalization by macrophages, it bypasses the normal endocytic pathway and occupies a replicative phagosome bound by endoplasmic reticulum . Here, we show that lysis of macrophages and red blood cells by L . pneumophila was dependent on dotA and other loci known to be required for proper targeting of the phagosome and replication within the host cell . Cytotoxicity occurred rapidly during a high-multiplicity infection, required close association of the bacteria with the eukaryotic cell and was a form of necrotic cell death accompanied by osmotic lysis . The differential cytoprotective ability of high-molecular-weight polyethylene glycols suggested that osmotic lysis resulted from insertion of a pore less than 3 nm in diameter into the plasma membrane . Results concerning the uptake of membrane-impermeant fluorescent compounds of various sizes are consistent with the osmoprotection analysis . Therefore, kinetic and genetic evidence suggested that the apparent ability of L . pneumophila to insert a pore into eukaryotic membranes on initial contact may play a role in altering endocytic trafficking events within the host cell and in the establishment of a replicative vacuole.

Plant Mol Biol, 1998 Feb, 36(3), 427 - 37
cDNA cloning, substrate specificity and expression study of tobacco caffeoyl-CoA 3-O-methyltransferase, a lignin biosynthetic enzyme; Martz F et al.; Four caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) cDNA clones were isolated from RNA extracted from TMV-infected tobacco leaves using an heterologous DNA probe . The cDNAs were 84-93% identical in their nucleotide sequences, indicating that they are the products of four closely related genes . A comparison of the CCoAOMT cDNAs with database sequences and Southern blot analysis indicated that they are encoded by a new CCoAOMT family of tobacco . Overall expression of this gene family in tobacco tissues was investigated by RNA blot analysis . The expression of each individual gene was studied by RT-PCR coupled with RFLP analysis of PCR products, taking advantage of the presence of specific restriction sites in each cloned cDNA . Two members of the CCoAOMT gene family appeared to be constitutively expressed in various plant organs and tissues whereas the two others were preferentially expressed in flower organs, after tobacco mosaic virus (TMV) infection or elicitor treatment of leaves . The CCoAOMT enzymatic protein expressed in bacteria was purified and shown to be specific for the caffeoyl-CoA and 5-hydroxyferuloyl-CoA esters and to have no activity against free caffeic acid and 5-hydroxyferulic acid . The pattern of CCoAOMT transcript accumulation during development of tobacco stem was found closely related to that of COMT I genes which have been shown to be specifically involved in lignin biosynthesis . Moreover, the inhibition of COMT I gene expression in transgenic tobacco was also shown to decrease CCoAOMT gene expression, particularly in the most lignified tissues . Thus, the expression pattern and the substrate specificity of tobacco CCoAOMT sustain a preferential role in lignin biosynthesis.

Plant Mol Biol, 1998 Feb, 36(3), 353 - 63
Characterization and transcriptional regulation of the Synechocystis PCC 6803 petH gene, encoding ferredoxin-NADP+ oxidoreductase: involvement of a novel type of divergent operator; van Thor JJ et al.; The petH gene, encoding ferredoxin-NADP+ oxidoreductase (FNR), has been characterised in the unicellular cyanobacterium Synechocystis PCC 6803 . Its product, FNR, was heterologously produced and functionally characterized . The start-site of the monocystronic petH transcript was mapped 523 bp upstream of the predicted PetH initiation codon, resulting in an unusually large 5'-untranslated region . The 5' end of the petH transcript is situated within the open reading frame of phosphoribulokinase (encoded by prk), which is transcribed in opposite orientation with respect to petH . The transcription start site of the prk transcript was mapped 219 bp upstream of the initiation codon, resulting in a 223 bp antisense region between both transcripts . Under many conditions the expression of both genes (i.e . petH and prk) is co-regulated symmetrically at the transcriptional level, as was concluded from both northern hybridization experiments and from primer extension analyses; it became uncoupled, however, when specifically petH expression was stimulated, independent of prk expression, by stressing the Synechocystis cells with high salt concentrations . A model for a new type of bidirectional operator, regulating the expression of petH and prk, is proposed.

Oper Dent, 1997 Jul-Aug, 22(4), 149 - 58
Biocompatability of compomer restorative systems on nonexposed dental pulps of primate teeth; Tarim B et al.; This study evaluated the histologic response of total-etched and nonetched compomer restored cavity preparations . One hundred fifteen class 5 cavity preparations were placed in the teeth of four healthy adult monkeys at 7, 27, and 90 days . A 37% H3PO4 was applied for 10 seconds and rinsed in total-etched preparations . No statistical differences were seen in inflammatory reactions among total-etched or nonetched compomers at 7, 27, and 90 days . There were no statistical differences in inflammatory cell responses among all compomer systems in regard to time intervals . Pulpal responses of compomers were greater than IRM at each time period . Pulp responses were associated with stained bacteria in 32 of 89 compomer teeth . No necrotic pulps were seen in any teeth . Statistical data show a positive correlation (P < 0.05) between bacterial presence and pulpal inflammation . IRM pulps showed no inflammation or bacterial staining . Compomers are biologically compatible with pulp tissues when bacteria are excluded.

J Clin Laser Med Surg, 1996 Feb, 14(1), 7 - 11
Long-term clinical evaluation of endodontically treated teeth by Nd:YAG lasers; Gutknecht N et al.; It was possible for the patients to avoid surgical intervention in a number of complicated periapical endodontic situations by means of Nd:YAG laser-assisted sterilization . A WSR has only very good primary results and the long-term successes are very limited . Once a lesions has healed in the manner explained in this study, in other words, with regeneration of the periapical anatomy, there is a very good long-term prognosis . Laser technology is an instrument whose overall effects represent a decisive improvement in the efficiency of conservative endodontic treatment in fields that were previously outside our sphere of influence.

Vojnosanit Pregl, 1997 Nov-Dec, 54(6), 541 - 8
{Physical therapy in the rehabilitation of patients with aerobic infections of the extremities}; Durovic A et al.; OBJECTIVE: To evaluate how infection of extremity after war wound influenced the possibilities and immediate effects of a physical therapy . METHODS: The retrospective clinical investigation comparing two groups: group A (n = 86) with infection, group B (n = 87) without infection . Main indicators for possibilities of the physical therapy were the numbers and types of physical procedures used . For the estimation of immediate effects of physical therapy the muscle power and the range of motion were used . RESULTS: The number of daily physical procedures in the group with infection, compared to the group without infection, was significantly lesser ((A: 2.87 +/- 1.73; B: 4.02 +/- 1.73; p < 0.001) . The patients with infection were significantly less frequently submitted to thermotherapy, hydrotherapy, interferent current and electrostimulation . Patients with infection, compared to patients without infection, had significantly poorer improvement of amplitude of analyzed movements at the end of treatment (A: 6.66 +/- 7.28 degrees; B: 16.66 +/- 14.79 degrees; p < 0.001) . CONCLUSION: The infection of the extremities limited the possibilities and reduced the immediate effects of physical therapy.

Nephrol Dial Transplant, 1998 Jan, 13(1), 130 - 3
Successful use of single-lumen, urokinase immobilized femoral catheters as a temporary access for haemodialysis; Takeda K et al.; METHODS: Placement of a femoral vein catheter as a temporary vascular access for haemodialysis was conducted and the indications, catheter patency rate, and incidence of catheter-related infections were examined . An urokinase immobilized femoral vein catheter (UIFC) is a soft polyurethane single-lumen catheter 2.7 mm in diameter and 22 cm in length which needs no heparin infusion (Japan Shawood Co., Ltd., Tokyo; Unitica Co., Ltd., Hyogo, Japan) . A soft silicon rubber was attached to the tip of the catheter in order to avoid excessive bleeding during insertion . Aseptic adhesive wound dressing was employed at the exit-site which was cleansed with popidone-iodine and renewed at each dialysis session . RESULTS: Eighty-one UIFCs were used for haemodialysis in 64 patients (acute renal failure: 11; vascular access trouble: 53; initiation of chronic dialysis: 17) . The average age of the patients was 58 +/- 13 years, ranging from 26 to 80 years . The mean duration of catheter indwelling was 22.4 +/- 13.1 days . An adequate blood flow of 180-200 ml/min was obtained through UIFC and returned to another peripheral vein punctured at each dialysis session . Unexplained fever occurred in four cases while the UIFC was in place (4.9%) but culture of either blood or the catheter tip was negative for bacteria . The catheter was removed immediately and fever subsided in all cases . The overall catheter survival rate was 84% at 34 days calculated using the Kaplan-Meier method . Catheter insertion was easy to perform and no serious complications such as pulmonary embolism or septicaemia occurred . CONCLUSION: Our modified type of UIFC is very useful as a temporary access for haemodialysis with a very low incidence of catheter-related infections and no need for heparinization . Excellent catheter patency was maintained with the plug system and careful dressing techniques without unnecessary bleeding during catheter care.

Nutr Rev, 1998 Jan, 56(1 Pt 1), 1 - 8
Human adult-onset lactase decline: an update; Lee MF et al.; Human adult-onset lactase decline is a biologic feature characteristic of the maturing intestine in the majority of the world's population . The digestion and absorption of lactose, the major carbohydrate in milk and also the main substrate for lactase, is often variable, a consequence of lactase levels, gastric emptying rate, and colonic salvage . Although commercially available "lactase" products alleviate symptoms in many lactose-intolerant people, a greater understanding of this variability in lactose tolerance could lead to interventions that reduce the rate of gastric emptying and/or increase the proliferation of lactose-metabolizing bacteria in the colon, leading to more efficient lactose utilization . Adult-onset lactase decline appears to be a risk factor for developing osteoporosis, owing to avoidance of dairy products or interference of undigested lactose with calcium absorption . Elderly with both adult-onset lactase decline and atrophic gastritis or those undergoing anti-ulcer treatment may have an increased risk of low calcium absorption owing to the lack of gastric acid that facilitates calcium uptake . Thus, lactose-intolerant elders should monitor their calcium nutrition status carefully.

Przegl Lek, 1997, 54(7-8), 561 - 4
{Some aspects of ozone therapy}; Antoszewski Z et al.; Authors present ozone-biochemistry, describe ozone production and application method of oxygen-ozone mixture . Authors describe application pf ozone therapy to treatment of virus or bacteria diseases and others as well as contraindications to the ozone therapy, side effects . Authors evaluate also effects of ozone therapy.

Mikrobiol Z, 1997 Sep-Oct, 59(5), 13 - 21
{The chemical composition and biological activity of the glyco polymers in Ralstonia solanacearum (Yabuchi et al., 1995)}; Varbanets LD et al.; Lipopolysaccharide and extracellular glyco polymers were isolated from cells of phytopathogenic bacteria Ralstonia solanacearum . It was established that the O-specific polysaccharides are characterized by a linear structure, composed of tetrasaccharide repeating units containing three L-rhamnose residues and one of N-acetylglucosamine residue . Core oligosaccharide along with typical monosaccharides such as rhamnose, glucose, heptose, KDO and glucosamine included fucose, galactose and arabinose . Serological activity of lipopolysaccharide is due to both O-specific polysaccharide and lipid A component . Extracellular glyco polymers contained both neutral (GP 1) and charged (GP 2 and GP 3) components . Rhamnose and glucose (GP 1, GP 2) or galactose (GP 3) were predominant monosaccharides, GP 2 displayed a high phytotoxic action in respect to tomato plants.

Br Dent J, 1998 Jan 10, 184(1), 33 - 8
Is there a link between periodontal disease and coronary heart disease?
Seymour RA, Steele JG.
OBJECTIVE: To provide a critical review of the studies completed to date that have investigated a link between coronary heart disease and dental health . DESIGN: Retrospective analysis . SETTING: Mainly hospital-based patients or subjects involved in longitudinal health care studies . MAIN OUTCOME MEASURES: The incidence of coronary heart disease and its relationship to dental health and other recognised risk factors . RESULTS: Evidence suggests that dental health, in particular periodontal disease, may be a significant risk factor for coronary heart disease and further coronary events . Possible biological mechanisms that link the two diseases are appraised . CONCLUSIONS: There does appear to be increasing evidence that a relationship exists between dental health and coronary heart disease, especially in males aged 40-50 years . The presence of a hyperinflammatory monocyte phenotype may provide a common biological mechanism that links the two diseases.

Br Dent J, 1998 Jan 10, 184(1), 12 - 6
Advances in periodontal diagnosis . 1 . Traditional clinical methods of diagnosis; Eley BM et al.; This series will consider the limitations of traditional periodontal diagnostic techniques and the recent advances which have sought to overcome them . It will cover improvements in probing and radiographic techniques and also discusses the attempts to find bacterial or tissue-derived markers which will diagnose or predict periodontal disease activity . The first paper describes the traditional methods of periodontal diagnosis.

J Clin Gastroenterol, 1997, 25 Suppl 1, S149 - 63
Helicobacter pylori factors involved in the development of gastroduodenal mucosal damage and ulceration; Figura N; Many putative virulence determinants of Helicobacter pylori are believed to trigger and worsen the gastroduodenal mucosa damage observed in infected patients . H . pylori urease reacts with the gastric urea and generates ammonia; ammonia combines with water and yields ammonium hydroxide, which is cytotoxic . Ammonia may also inhibit cell proliferation and cause indirect mucosal injury by stimulating neutrophils . Phospholipases may damage the gastric mucosa by degrading phospholipids and generating precursors of ulcerogenic components . Other enzymes, such as protease, neuraminidase, fucosidase, and alcohol dehydrogenase, can contribute to damage of the gastric epithelium by destroying the integrity of mucus or by inducing lipid peroxidation . Infection by vacuolating cytotoxic (VacA+) H . pylori strains is considered to constitute increased risk for development of peptic ulcer and gastric cancer . Exploration of the vacA gene structure has shown the existence of strongly toxigenic strains, and has confirmed at the molecular level the increased ulcerogenic potential of VacA+ H . pylori strains . A pathogenicity island called cag has been recently described in Type 1 H . pylori strains (VacA+/CagA+).cag contains the cagA gene (whose expression is associated with toxigenicity) and many genes, some of which are highly homologous to virulence genes of other virulent bacteria, that account for the enhanced pathogenic potential of CagA+ organisms.

Immunol Res, 1998, 17(1-2), 269 - 78
Immunobiology of interleukin-12; Trinchieri G; Interleukin-12 (IL12) is a heterodimeric cytokine which is produced by phagocytic cells and antigen-presenting cells within a few hours of infection, particularly in the case of bacteria and intracellular parasites, and acts as a proinflammatory cytokine, activating natural killer (NK) cells, and, through its ability to induce interferon-gamma(IFN gamma) production, enhancing the phagocytic and bacteriocidal activity of phagocytic cells and their ability to release proinflammatory cytokines, including IL12 itself . Furthermore, IL12 produced during the early phases of infection and inflammation, sets the stage for the ensuing antigen-specific immune response, favoring differentiation and function of T helper type 1 (Th1) T cells while inhibiting the differentiation of Th2 T cells . Thus, IL12, in addition to being a potent proinflammatory cytokine, is a key immunoregulator molecule in Th1 responses.

J Biol Chem, 1998 Jan 30, 273(5), 2874 - 84
Efficient generation of major histocompatibility complex class I-peptide complexes using synthetic peptide libraries; Stevens J et al.; The use of synthetic random peptide libraries is a powerful technology for the study of many aspects of antigen presentation and peptide selection by major histocompatibility complex (MHC) molecules . Here we have used them in conjunction with a recombinant system to determine the peptide binding motifs of three classical class I MHC molecules of the laboratory rat: RT1-Aa, RT1-Au, and RT1-A1c . Described is a method for producing large amounts of soluble class I heavy and light chains in bacteria . Refolding RT1-Aa heavy chain (HC) with rat beta2-microglobulin (beta2m) in the presence of a specific peptide and the subsequent purification of the complex yielded conformationally correct material . This was assessed by gel chromatography, SDS-polyacrylamide gel electrophoresis, isoelectric focussing gel electrophoresis, enzyme-linked immunosorbent assay, and fluorescence-activated cell sorter analysis employing a previously unreported method utilizing a His-Tag affinity silica . By refolding RT1-Aa HC and rat beta2m around a random nonapeptide library and subjecting the resulting complex to acid elution of the bound peptides and pool sequencing, the peptide binding motif for this MHC class I molecule was determined . Results corresponded well with those previously determined from naturally bound peptides and in addition gave a clear and unambiguous signal for the C-terminal anchor residue . This method was then applied to determine the previously undescribed binding motifs for RT1-Au and RT1-A1c . For both molecules, the whole motif was confirmed from naturally bound peptides . We propose this method as an alternative way to obtain the whole class I MHC peptide motif, particularly when a specific antibody is unavailable and/or natural expression of the class I molecule of interest is low.

EMBO J, 1998 Jan 2, 17(1), 170 - 80
AGO1 defines a novel locus of Arabidopsis controlling leaf development; Bohmert K et al.; An allelic series of the novel argonaute mutant (ago1-1 to ago1-6) of the herbaceous plant Arabidopsis thaliana has been isolated . The ago1 mutation pleotropically affects general plant architecture . The apical shoot meristem generates rosette leaves and a single stem, but axillary meristems rarely develop . Rosette leaves lack a leaf blade but still show adaxial/abaxial differentiation . Instead of cauline leaves, filamentous structures without adaxial/abaxial differentiation develop along the stem and an abnormal inflorescence bearing infertile flowers with filamentous organs is produced . Two independent T-DNA insertions into the AGO1 locus led to the isolation of two corresponding genomic sequences as well as a complete cDNA . The AGO1 locus was mapped close to the marker mi291a on chromosome 1 . Antisense expression of the cDNA resulted in a partial mutant phenotype . Sense expression caused some transgenic lines to develop goblet-like leaves and petals . The cDNA encodes a putative 115 kDa protein with sequence similarity to translation products of a novel gene family present in nematodes as well as humans . No specific function has been assigned to these genes . Similar proteins are not encoded by the genomes of yeast or bacteria, suggesting that AGO1 belongs to a novel class of genes with a function specific to multicellular organisms.

Curr Microbiol, 1998 Jan, 36(1), 9 - 12
Possible involvement of cysteine and histidine residues in the (NH4+ + Na+)-activated ATPase of an anaerobic alkaliphile, Amphibacillus xylanus; Okano Y et al.; Effect of various inhibitors on the (NH4+ + Na+)-activated ATPase of an anaerobic alkaliphile, Ep01(a strain of Amphibacillus xylanus), was examined . Among the chemicals tested, the enzyme was drastically inactivated by p-chloromercuribenzoic acid and diethyl pyrocarbonate . The ATPase activity of the enzyme, which was inactivated by p-chloromercuribenzoic acid and diethyl pyrocarbonate, was remarkably restored by beta-mercaptoethanol and hydroxylamine, respectively, suggesting the involvement of cysteine and histidine residues in the enzyme activity . Analysis of the inhibition kinetics by diethyl pyrocarbonate indicated that modification of a single histidine residue per ATPase molecule was sufficient to inactivate the enzyme.

J Cell Sci, 1998 Jan, 111 ( Pt 1), 141 - 8
Degradation of phagosomal components in late endocytic organelles; Tjelle TE et al.; Phagosomes are formed when phagocytic cells ingest particles such as bacteria, viruses or synthetic beads of different kinds . The environment within the phagosome gradually changes to generate degradative conditions . These changes require multiple interactions between the maturing phagosomes and the endocytic and the biosynthetic pathway . The phagosomes probably communicate with endocytic organelles by a transient fusion event, often referred to as the 'kiss-and-run' hypothesis . We have studied the role of endocytic organelles in the phagocytic pathway of J774 cells, a mouse macrophage cell line . We have used magnetic Dynabeads coated with 125ITC-IgG and 125ITC-OVA as phagocytic probes and were able to isolate the phagosomal fraction by means of a magnet . To separate lysosomes from other organelles in the endocytic pathway we allowed the cells to endocytose a pulse of colloidal gold particles complexed with ovalbumin . By combining this density shift technique with subcellular fractionation of a postnuclear supernatant in Percoll gradients we could isolate three endocytic fractions corresponding to early endosomes (the light Percoll fraction), late endosomes (the dense Percoll fraction) and lysosomes (the gold fraction) . We observed that the proteins linked to the ingested beads are initially cleaved in the phagosomes . This cleavage is inhibited by leupeptin, a thiol-protease inhibitor, and requires an acidic environment . However, efficient communication between the phagosomes and the endocytic pathway leads to the transfer of dissociated phagocytosed peptides of different sizes to late endosomes and lysosomes for further processing . Consequently, the late endosomes and the lysosomes may be involved in the degradation of phagocytosed compounds.

Arch Histol Cytol, 1997 Dec, 60(5), 493 - 502
Demonstration and organization of duct-associated lymphoid tissue (DALT) of the main excretory duct in the monkey parotid gland; Matsuda M et al.; Duct-associated lymphoid tissue (DALT) of the main excretory duct in the monkey parotid gland was first demonstrated by light microscopy and by transmission and scanning electron microscopy . The DALT included a follicular area, a parafollicular area and a specialized overlying epithelium with distinct fine-structural elements . There was usually a solitary lymphoid follicle located in the subepithelial area near the orifice of the parotid duct . The lymphoid follicles typically had a distinct germinal center . Numerous immune cells often infiltrated into the epithelium overlying the lymphoid follicle . The superficial epithelial cells of the DALT were larger and flatter than the ordinary duct epithelial cells, and had short irregular microvilli on their luminal surface . They were also in close contact with immune cells such as dendritic cells and lymphocytes . Goblet cells were rare in this area . In addition, bacteria, seen at the duct orifice, were sometimes taken up by the flattened epithelial cells near the orifice . Latex microspheres administrated as particulate antigens at the duct orifice were selectively taken up by the flattened epithelial cells and also by the intraepithelial dendritic cells of the DALT . These morphological findings suggest that the epithelial cells of the DALT in parotid glands take up antigens from the duct lumen and transport them to adjacent immune cells, and that the DALT in parotid glands may serve as one of the inductive sites in the common mucosal immune system.

Immunopharmacology, 1997 Dec, 38(1-2), 207 - 13
Complement factor I deficiency in a family with recurrent infections; Leitao MF et al.; Factor I deficiency causes a permanent, uncontrolled activation of the alternative pathway resulting in an increased turnover of C3 and consumption of factor B, factor H and properdin . Factor I deficiency is clinically associated with recurrent bacterial infections already in early infancy, mainly affecting the upper and lower respiratory tract, or presenting as meningitis or septicemia . We here report on a Brazilian family (n = 9) with known consanguinity, where in 3/7 children, suffering from chronic otitis, meningitis, and respiratory infections, a complete factor I deficiency was recognized . One of the patients died after fulminant sepsis . Hemolytic activity of the alternative pathway was not detectable in the patients' sera due to decreased plasma concentrations of C3, factor B and properdin . As a consequence of factor I deficiency, C3b could not be metabolized with the result that no C3-derived split products (C3dg/C3d) were detectable in the patients' sera . In vitro reconstitution with purified factor I restored the regulatory function in the patients' sera with the subsequent cleavage of C3b to C3c and C3dg . Factor H levels were decreased in all patients' sera and found to be tightly complexed with C3b resulting in a modified electrophoretic mobility . Upon factor I reconstitution, factor H was released from C3b regaining its beta 1 electrophoretic mobility . Complement-mediated biological functions like opsonization of bacteria, chemotactic activity and phagocytosis in these patients were impaired . The parents (cousins, 2nd degree) and 3/4 siblings had significantly reduced factor I plasma levels without further alteration in their complement profile . 3 of these obviously heterozygously deficient family members suffered from recurrent bacterial infections of different frequency and severity.

J Prosthet Dent, 1998 Jan, 79(1), 79 - 89
The soft tissue response to osseointegrated dental implants; Weber HP et al.; The use of dental implants in the treatment of fully edentulous patients has become an important addition in oral/dental rehabilitation . The fact that these implants penetrate the oral mucosa can lead to the assumption that peri-implant tissues, similar to the periodontal tissues, are fulfilling an important function as a barrier to protect the bony anchorage underneath . It has been shown that insufficient plaque removal may lead to peri-implant tissue disease with bone loss similar to teeth . However, it is unclear how important this cause is as a source of implant failure compared with other factors, such as inadequate bone healing, unfavorable quantity and quality of bone, or (bio)mechanical and functional problems . It is also not understood if peri-implant epithelium and connective tissue are equally needed and/or qualified to slow down or prevent tissue breakdown as their periodontal counterparts . The scientific work focusing on peri-implant soft tissues has dramatically increased in the past few years . Most studies to date have examined and described their structure but little data exist on their true biologic function . This review analyzes the current understanding of morphologic and clinical features of the peri-implant soft tissues . Furthermore, evidence shall be provided that peri-implant soft tissues do not interfere with the current favorable results obtained when treating the edentulous patient with osseointegrated implants.

Gynecol Obstet Invest, 1998, 45(1), 35 - 40
Stimulated polymorphonuclear leukocytes in vaginal secretions from patients with preterm labor; Matsubara S et al.; The purpose of this study was to examine evidence for the presence of activated vaginal leukocytes in women with preterm labor . Vaginal polymorphonuclear leukocytes from 7 patients in preterm labor (24-32 weeks of gestation) as well as from 7 control women with uncomplicated pregnancy were analyzed morphologically using transmission electron microscopy . Peroxidase and NADPH oxidase cytochemistry was also performed . Viable leukocytes were abundant in patients in preterm labor . Phagosomes, phagocytosis of bacteria, attachment of primary granules to the phagosomal membrane, and cell surface projections were observed in the vaginal leukocytes but not in the peripheral blood leukocytes . Peroxidase activity was visible on the cell surface, the phagosomal membrane, and the primary granules . NADPH oxidase activity was demonstrated on the cell surface of leukocytes . Morphological and cytochemical features indicated that vaginal polymorphonuclear leukocytes were stimulated in situ . Such stimulated leukocytes may play a role in the pathogenesis or pathophysiology of preterm labor.

Clin Exp Immunol, 1998 Jan, 111(1), 36 - 47
The surface epithelium of recurrent infected palatine tonsils is rich in gammadelta T cells; Olofsson K et al.; Using a large panel of MoAbs in quantitative morphometric analysis of immunohistochemically stained tissue sections, we compared the frequency and distribution of immune cells in palatine tonsils from patients with recurrent tonsillitis (RT) and patients with idiopathic tonsillar hypertrophy (ITH) . We found that differences between the two patient groups in leucocyte populations were limited to the surface epithelium, whereas the cellular composition of interfollicular and follicular areas was similar . Most intraepithelial lymphocytes were CD8+ T cells in both groups . However, the number of intraepithelial T cells was significantly higher in RT compared with ITH . This was due to a selective increase in the number of intraepithelial CD8+ gammadelta T cells utilizing Vdelta1 and Vgamma9 . In both patient groups the majority of the intraepithelial gammadelta T cells expressed Vdelta1 and Vgamma9 . Subepithelially, gammadelta T cells utilizing Vgamma9 dominated over cells utilizing Vgamma8, while equal proportions expressed Vdelta1 and Vdelta2 . These results suggest that cells utilizing the otherwise rare combination Vdelta1/Vgamma9 in their T cell receptors (TCR) may constitute a major gammadelta T cell population in palatine tonsils and are probably reactive to antigens specific to the tonsillar milieu . Furthermore, they indicate that preferentially this gammadelta T cell subpopulation is involved in immune reactions within the surface epithelium in RT . We speculate that gammadelta T cells are involved in clearing infectious bacteria at the tonsillar surface and in limiting inflammatory responses in the tonsils . Both local expansion and infiltration of blood cells probably contribute to the high numbers of gammadelta T cells in RT patients.

Appl Environ Microbiol, 1997 Dec, 63(12), 4853 - 8
Factors affecting lactate and malate utilization by Selenomonas ruminantium; Evans JD et al.; Lactate utilization by Selenomonas ruminantium is stimulated in the presence of malate . Because little information is available describing lactate-plus-malate utilization by this organism, the objective of this study was to evaluate factors affecting utilization of these two organic acids by two strains of S . ruminantium . When S . ruminantium HD4 and H18 were grown in batch culture on DL-lactate and DL-malate, both strains coutilized both organic acids for the initial 20 to 24 h of incubation and acetate, propionate, and succinate accumulated . However, when malate and succinate concentrations reached 7 mM, malate utilization ceased, and with strain H18, there was a complete cessation of DL-lactate utilization . Malate utilization by both strains was also inhibited in the presence of glucose . S . ruminantium HD4 was unable to grow on 6 mM DL-lactate at extracellular pH 5.5 in continuous culture (dilution rate, 0.05 h-1) and washed out of the culture vessel . Addition of 8 mM DL-malate to the medium prevented washout on 6 mM DL-lactate at pH 5.5 and resulted in succinate accumulation . Addition of malate also increased bacterial protein, acetate, and propionate concentrations in continuous culture . These results suggest that 8 mM DL-malate enhances the ability of strain HD4 to grow on 6 mM DL-lactate at extracellular pH 5.5.

Ann Acad Med Stetin, 1997, 43, 143 - 59
{Diagnostic value of different methods applied for detecting Helicobacter pylori infection in gastric mucosa}; Korzonek M; The aim of the paper comprised: 1) estimating the incidence of Helicobacter pylori (H . pylori) infection in subjects directed to undergo endoscopic examination due to ailments involving the upper segments of the alimentary tract, 2) determination of the degree of H . pylorii infection detectability on the basis of invasive methods (bacterial culture, urease test and histological examination of specimens stained by Giemsa method) and non-invasive (serological investigation, skin test) with endoscopic image and histopathologic changes in gastric mucosa being talken into consideration, 3) assessing the titer of class IgG anti-H . pylori antibodies in subjects with endoscopic and histopathologic changes of gastric mucosa, infected by H . pylori, as well as persons after eradication of bacteria, 4) estimating the diagnostic value of individual methods . The study material consisted of 428 patients (224 women and 204 men) investigated at Endoscopy Laboratory of Internal Diseases Clinic in the years 1991-1994 . Bacterial cultures and urease tests were performed in all the studied subjects, 230 specimens stained by Giemsa method were examined histopathologically, in 351 subjects the titer of class IgG anti-H . pylori antibodies in blood serum were determined by ELISA method, while in 73 persons the skin test from the suspension of dead bacterial colonies was carried out . Histopathological examination of mucosal sections was accomplished in 396 studied subjects, assessing the histological type of mucosal inflammation in H . pylorii infected persons and in those having not been infected . The applicability of the respective diagnostic methods was examined by calculating the sensitivity and specificity of the given method, and taking into account the results of bacterial culture as the reference method . It is evident from the performed investigations that the majority of subjects, having been endoscopically studied because of ailments stemming from the upper segment of the alimentary tract, were infected by H . pylori (Tab . 1, 2, 3) . H . pylori colonisation in gastric mucosa was often accompanied by pathological changes of the stomach and duodenum in the endoscopic and histopathologic images . In the routine clinical diagnostics the urease test, histological examination of specimens stained by Giemsa method as well as bacterial culture are valuable methods of detecting H . pylorii infection . With regard to medium and high values of the titer of antibodies IgG anti-H . pylori, the serological investigation as a non-invasive method displays a high compliance with positive results of invasive examinations (Tab . 5, Fig . 1, 2, 3) . An early skin test may become a screening method for detecting H . pylori infection, after its methodical modification.

Rozhl Chir, 1997 Oct, 76(10), 510 - 3
{Infections in biliary surgery}; Krikava K et al.; The authors selected among patients who were operated in 1992-1996 on account of affections of the gallbladder and biliary pathways those patients where aerobic and anaerobic bile cultivation was made . The results of the detected bacterial species and their sensitivity to ATB are given in tables . According to the author these investigations may be of benefit to the surgeon when he has to decide on the administration of ARTB without knowing the bacterial strain (prevention or therapy) and thus overcome the time when he will know the results of cultivation.

Ann Ist Super Sanita, 1997, 33(2), 225 - 9
Molecular characterisation of Lyme disease borreliae using RAPD analysis and 16S rDNA sequencing; Bandi C et al.; Here we report the use of random amplified polymorphic DNAs (RAPDs) and sequence analysis of the genes encoding for the small subunit ribosomal RNA (16S rDNA) for the characterisation of Borrelia burgdorferi sensu lato strains recovered from Ixodes ricinus and from Lyme disease patients . All strains examined were assigned to the species Borrelia garinii . However, both RAPDs and 16S rDNAs revealed a level of genetic variation among the strains which appears higher than expected for a bacterial species . In addition, the data obtained agree with the clonal theory applied to Borrelia burgdorferi s.l . for explaining some traits of its epidemiology . According to this theory, particular strains should spread rapidly, leading to the diffusion of bacteria with a particular chromosomal genotype . Our results reveal high genetic variation even among strains isolated in the same period from a restricted geographic area . Moreover, the data here reported indicate that clonal diffusion of antigenic characteristics could also occur.

Proc Natl Acad Sci U S A, 1998 Jan 6, 95(1), 224 - 8
Universally conserved translation initiation factors; Kyrpides NC et al.; The process by which translation is initiated has long been considered similar in Bacteria and Eukarya but accomplished by a different unrelated set of factors in the two cases . This not only implies separate evolutionary histories for the two but also implies that at the universal ancestor stage, a translation initiation mechanism either did not exist or was of a different nature than the extant processes . We demonstrate herein that (i) the "analogous" translation initiation factors IF-1 and eIF-1A are actually related in sequence, (ii) the "eukaryotic" translation factor SUI1 is universal in distribution, and (iii) the eukaryotic/archaeal translation factor eIF-5A is homologous to the bacterial translation factor EF-P . Thus, the rudiments of translation initiation would seem to have been present in the universal ancestor stage . However, significant development and refinement subsequently occurred independently on both the bacterial lineage and on the archaeal/eukaryotic line.

J Mol Evol, 1997 Dec, 45(6), 708 - 11
ThiD-TenA: a gene pair fusion in eukaryotes; Ouzounis CA et al.; Computational analysis of the hypothetical open reading frame MJ0236 from Methanococcus jannaschii reveals its membership to a family of bacterial and eukaryotic proteins, predicted to be the HMP-P kinases involved in thiamin biosyntheis (ThiD) . The eukaryotic members of this family contain a C-terminal extension similar to a bacterial transcriptional activator (TenA), thus pointing to a fusion event that took place during cellular evolution . The C-terminal domain is absent from M . jannaschii . The significance of this observation is two-fold: first, this is a case where a fusion protein contains two domains with an unusual phylogenetic distribution, and second, the TenA domain is a rare case of a gene family involved in transcription present both in bacteria and eukaryotes.

Nucleic Acids Res, 1998 Jan 1, 26(1), 351 - 2
The ribonuclease P database; Brown JW; Ribonuclease P is responsible for the 5'-maturation of tRNA precursors . Ribonuclease P is a ribonucleoprotein, and in bacteria the RNA subunit alone is catalytically active in vitro , i.e., it is a ribozyme . The Ribonuclease P Database is a compilation of ribonuclease P sequences, sequence alignments, secondary structures, three-dimensional models, and accessory information, available via the World Wide Web .

Poult Sci, 1998 Jan, 77(1), 41 - 6
Peanut hulls as a litter source for broiler breeder replacement pullets; Lien RJ et al.; Broiler breeder pullets were reared on either peanut hulls or pine shavings to determine effects of litter type on growth performance and litter characteristics . Pullets were reared to 20 wk of age in rooms initially bedded with 8 cm of clean shavings or hulls . Heating and ventilation were standardized in all rooms . Restricted skip-a-day feeding was used to attain recommended growth curves . Water was continuously provided for ad libitum consumption . Litter and environmental variables were measured throughout rearing and 2 wk after pullets were removed from the litter materials . Feed consumption, BW, mortality, and uniformity at 20 wk were not affected by litter type; however, gizzard weights were decreased in pullets reared on hulls . Litter bulk density increased with use and was greater for shavings through 11 wk, but not thereafter . Particle size decreased with use in both litter types . Through 11 wk, there were more particles in the > 4 mm range and less in the < 1.7 mm range with hulls . Litter moisture increased with use but was not affected by litter type . Litter pH was greater in unused shavings, but during and after use was generally greater in hulls . With both litter types, litter and environmental ammonia levels increased to 11 wk then decreased; however, this effect was more pronounced for hulls . Bacteria populations were not affected by litter type; however, greater fungal populations were observed in shavings at 7 and 15 wk . Aflatoxins were detected in unused hulls but not shavings . Because aflatoxin levels decreased during use and Aspergillus flavus and Aspergillus parasiticus populations were not detected in samples collected during use, aflatoxins observed were presumed to have been formed prior to use . Peanut hulls performed similarly to pine shavings as a litter source for breeder pullets; however, the specific influence of the aflatoxins contained in this litter source on bird performance deserves further study.

J Immunol, 1998 Feb 15, 160(4), 1886 - 93
Morphine enhances macrophage apoptosis; Singhal PC et al.; Laboratory data indicate that morphine decreases the numbier of peritoneal and alveolar macrophages (Mphi) and compromises their phagocytic capability for immune complexes and bacteria . We hypothesize that morphine decreases the number of, as well as compromises the phagocytic capability of, Mphi by programming their death . We studied the effect of morphine on Mphi apoptosis in vivo as well as in vitro . Peritoneal Mphi harvested from morphine-treated rats showed DNA fragmentation . Morphine enhanced murine Mphi (J 774.16) apoptosis in a dose-dependent manner . Human monocytes treated with morphine showed a classic ladder pattern in gel electrophoretic and end-labeling studies . Morphine promoted nitric oxide (NO) production both under basal and LPS-activated states . N(G)-nitro-L-arginine methyl ester (L-NAME) and N(G)-monomethyl-L-arginine monoacetate (L-NMMA), inhibitors of NO synthase, attenuated the morphine-induced generation of NO by Mphi . Morphine also enhanced Mphi mRNA expression of inducible NO synthase (iNOS) . Since morphine-induced Mphi apoptosis was inhibited by L-NAME and L-NMMA, it appears that morphine-induced Mphi apoptosis may be mediated through the generation of NO . Morphine promoted the synthesis of Bax and p53 proteins by Mphi . Moreover, IL-converting enzyme (ICE)-1 inhibitor attenuated morphine-induced Mphi apoptosis . These studies suggest that morphine activates the induction phase of the apoptotic pathway through accumulation of p53 . The effector phase of morphine-induced apoptosis appears to proceed through the accumulation of Bax and activation of ICE-1 . The present study provides a basis for a hypothesis that morphine may be directly compromising immune function by promoting Mphi apoptosis in patients with opiate addiction.

J Immunol, 1998 Feb 15, 160(4), 1824 - 30
Toxoplasma gondii-infected cells are resistant to multiple inducers of apoptosis; Nash PB et al.; Infection with certain intracellular pathogens, including viruses and bacteria, may induce host cell apoptosis . On the other hand, infection with some viruses inhibits apoptosis . Complex protozoan parasites, including Toxoplasma gondii and members of Plasmodium, Leishmania, and Microsporidia, are also obligate intracellular pathogens, yet relatively little is known regarding their subversion of host cell functions . We now report that cells infected with T . gondii are resistant to multiple inducers of apoptosis, including Fas-dependent and Fas-independent CTL-mediated cytotoxicity, IL-2 deprivation, gamma irradiation, UV irradiation, and the calcium ionophore beauvericin . Inhibition of such a broad array of apoptosis inducers suggests that a mechanism common to many, or perhaps all, apoptotic pathways is involved . The inhibitory activity requires live intracellular parasite and ongoing protein synthesis . Despite T . gondii-mediated inhibition of DNA fragmentation, infected cells can still be lysed by CTL.

Clin Chim Acta, 1997 Nov 28, 267(2), 183 - 96
Detection of spiral and coccoid forms of Helicobacter pylori using a murine monoclonal antibody; Cao J et al.; Helicobacter pylori is the major cause of gastritis . The aim of this investigation was to develop a specific antibody, which recognizes both coccoid and spiral forms of Helicobacter pylori and to test this antibody on gastric biopsy sections known to harbour coccoid bacteria . Murine monoclonal antibodies against glycine-acid extracts of five strains of Helicobacter pylori were raised . Immunofluorescence and immunoelectron microscopy showed that one antibody of the IgG1 subclass was specific for both the spiral and coccoid forms . It reacted with a 28 kDa protein that was present in all the five strains tested . Using this antibody in an indirect immunofluorescence assay of formalin-fixed antral and corpus biopsy specimens from Helicobacter pylori-associated gastritis patients showed that nine of the nine antral and five of six corpus specimens harboured the coccoid form of Helicobacter pylori . This technique thus provides a rapid and specific detection of both the spiral and coccoid forms.

Digestion, 1998, 59(1), 1 - 15
A century of Helicobacter pylori: paradigms lost-paradigms regained; Kidd M et al.; The investigation of gastric bacteria properly began in the latter half of the nineteenth century when microscope resolution had sufficiently advanced . Whilst a bacterial etiology was demonstrated for dysentery, tuberculosis and syphilitic ulcers, problems in the isolation and culture of pure strains circumvented a role for bacteria in gastric pathology . Furthermore, dogma and the intellectual chorus were in harmony advocating that gastric acid was critical in ulcer disease . The consideration of a role for a pathogen or pepsin was regarded as whimsical in the context of mucosal ulceration . Indeed, the effects of acid inhibitory agents were held as gospel truth whilst the use of antibiotics or metallic ions were deemed to be quackery or at least ill judged . Nonetheless, spiral-shaped bacteria had been identified in both mucosa and gastric contents of patients as early as 1889 . Elegant studies had documented the infectivity of these organisms, and suggested but not proven a causative role in gastric disease . The prescient identification by Doenges of organisms associated with gastritis in both man and monkey, was buried by the observations of Palmer, and an opportunity for early progress lost . It required two decades and Antipodean pathological perspicacity to elucidate the warren of previous archaic gastric bacterial misinformation . The subsequent marshalling of clinical and pathological data established the fatal flaw in the mucosa to be bacteria and not only acid on the mucus shore . It is now widely apparent that Helicobacter is ubiquitous, pathological and, a century after its initial discovery, still remains a paradox of as yet incompletely determined biological consequence . It is of note that an organic helical configuration has twice in this century provided biological information of unique import.

Biochim Biophys Acta, 1998 Jan 8, 1379(1), 69 - 75
Intestinal flora is not an intermediate in the phylloquinone-menaquinone-4 conversion in the rat; Ronden JE et al.; To elucidate the role of intestinal bacteria in the conversion of phylloquinone into menaquinone-4 (MK-4) we investigated the tissue distribution of vitamin K in germ-free rats . The rats were made vitamin K deficient by feeding a vitamin K-free diet for 13 days . In a subsequent period of 6 days, phylloquinone and menadione were supplied via the drinking water in concentrations of 10 and 50 micromol l(-1) . Menadione supplementation led to high levels of tissue MK-4, particularly in extrahepatic tissues like pancreas, aorta, fat and brain . Liver and serum were low in MK-4 . Phylloquinone supplementation resulted in higher phylloquinone levels in all tissues when compared with vitamin K-deficient values . The main target organs were liver, heart and fat . Remarkably, tissue MK-4 levels were also higher after the phylloquinone supplementation . The MK-4 tissue distribution pattern after phylloquinone intake was comparable with that found after menadione intake . Our results demonstrate that the conversion of phylloquinone into MK-4 in extrahepatic tissues may occur in the absence of an intestinal bacterial population and is tissue specific . A specific function for extrahepatic MK-4 or a reason for this biochemical conversion of phylloquinone into MK-4 remains unclear thus far.

Crit Care Med, 1998 Feb, 26(2), 392 - 408
Practice parameters for evaluating new fever in critically ill adult patients . Task Force of the American College of Critical Care Medicine of the Society of Critical Care Medicine in collaboration with the Infectious Disease Society of America; O'Grady NP et al.; OBJECTIVE: To develop practice parameters for the evaluation of adult patients who develop a new fever in the intensive care unit (ICU) for the purpose of guiding clinical practice . PARTICIPANTS: A task force of 13 experts in disciplines related to critical care medicine, infectious diseases, and surgery was convened from the membership of the Society of Critical Care Medicine, and the Infectious Disease Society of America . EVIDENCE: The task force members provided the personal experience and determined the published literature (MEDLINE articles, textbooks, etc.) from which consensus would be sought . Published literature was reviewed and classified into one of four categories, according to study design and scientific value . CONSENSUS PROCESS: The task force met several times in person and twice monthly by teleconference over a 1-yr period of time to identify the pertinent literature and arrive at consensus recommendations . Consideration was given to the relationship between the weight of scientific evidence and the experts' opinions . Draft documents were composed and debated by the task force until consensus was reached by nominal group process . CONCLUSIONS: The panel concluded that, because fever can have many infectious and noninfectious etiologies, a new fever in a patient in the ICU should trigger a careful clinical assessment rather than automatic orders for laboratory and radiologic tests . A cost-conscious approach to obtaining cultures and imaging studies should be undertaken if it is indicated after a clinical evaluation . The goal of such an approach is to determine, in a directed manner, whether or not infection is present, so additional testing can be avoided and therapeutic options can be made.

Microbiology, 1998 Jan, 144 ( Pt 1), 229 - 39
Metabolism is required for chemotaxis to sugars in Rhodobacter sphaeroides; Jeziore-Sassoon Y et al.; Chemotaxis towards carbohydrates is mediated, in enteric bacteria, either by the transport-independent, methylation-dependent chemotaxis pathway or by transport and phosphorylation via the phosphoenolpyruvate (PEP)-dependent phosphotransferase system (PTS) . This study shows that Rhodobacter sphaeroides is chemotactic to a range of carbohydrates but the response involves neither the classical methyl-accepting chemotaxis protein (MCP) pathway nor the PTS transport pathway . The chemoattractant fructose was transported by a fructose-specific PTS system, but transport through this system did not appear to cause a chemotactic signal . Chemotaxis to sugars was inducible and occurred with the induction of carbohydrate transport systems and with substrate incorporation . A mutation of the glucose-6-phosphate dehydrogenase gene (zwf) inhibited chemotaxis towards substrates metabolized by this pathway although transport was unaffected . Chemotaxis to other, unrelated, chemoattractants (e.g . succinate) was unaffected . These data, in conjunction with the fact that mannitol and fructose (which utilize different transport pathways) compete in chemotaxis assays, suggest that in R . sphaeroides the chemotactic signal is likely to be generated by metabolic intermediates or the activities of the electron-transport chain and not by a cell-surface receptor or the rate or mode of substrate transport.

Microbiology, 1998 Jan, 144 ( Pt 1), 183 - 91
pqqA is not required for biosynthesis of pyrroloquinoline quinone in Methylobacterium extorquens AM1; Toyama H et al.; Methylobacterium extorquens AM1 is a facultative methylotroph that oxidizes methanol via the pyrroloquinoline quinone (PQQ)-linked enzyme methanol dehydrogenase . In M . extorquens AM1 and other PQQ-synthesizing bacteria, several genes are involved in the synthesis of PQQ and one of these, pqqA, has been proposed to encode a peptide precursor of PQQ . In other PQQ-synthesizing bacteria, pqqA is required for PQQ production . In this study, it is shown that both deletion and insertion mutants of pqqA in M . extorquens AM1 grow normally on methanol and produce PQQ . The level of PQQ production is reduced in the insertion mutant, but it is sufficient to allow normal growth on methanol . These results suggest either that a different peptide in M . extorquens AM1 can substitute for PqqA in pqqA mutants, or that PqqA-like peptides may not be obligatory precursors of PQQ . In addition, it is shown that the methanol oxidation transcriptional regulator gene, mxbM, is required for normal methanol induction of PQQ synthesis.

Int J Immunopharmacol, 1997 Jun, 19(6), 355 - 8
Potent anti-inflammatory activity of pheophytin a derived from edible green alga, Enteromorpha prolifera (Sujiao-nori); Okai Y et al.; Recently, a chlorophyll-related compound, pheophytin a, has been identified from an edible green alga, Enteromorpha prolifera (Sujiao-nori in Japanese) as a potent suppressive substance against genotoxin-induced umu C gene expression in a tester bacteria (Okai and Higashi-Okai, 1997, J . Sci . Food Agricul . 71, 531-535) . In the present study, anti-inflammatory effects of pheophytin a from Enteromorpha prolifera have been analyzed using in vitro and in vivo experiments . 1 . Pheophytin a suppressed the production of superoxide anion (O2-) in mouse macrophages induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) using the cytochrome C reduction method . 2 . Pheophytin a caused a suppressive effect against formyl-Met-Leu-Phe, (FMLP)-induced chemotaxis of human polymorphonuclear leukocytes (PMNs) in Boyden's chamber experiment . 3 . Pheophytin a exhibited a significant suppression against TPA-induced inflammatory reaction such as edema formation in BALB/c mouse ear . These results suggest that pheophytin a from Enteromorpha prolifera has a potent anti-inflammatory activity.

Oral Microbiol Immunol, 1997 Oct, 12(5), 303 - 10
Estimation of serum antibody to subgingival species using checkerboard immunoblotting; Sakellari D et al.; Measurement of serum antibody to subgingival bacterial species has been useful in discriminating possible periodontal pathogens and in assessing the host's immune response to subgingival species . An immunoassay system was developed to measure the level of serum antibody to multiple subgingival species in multiple serum samples on a single nitrocellulose membrane . The principle steps of the assay are the following: 1) binding of antigens from bacterial preparations and protein A in parallel lanes on nitrocellulose membranes; 2) incubation of known concentrations of human immunoglobulin as well as various dilutions of serum from patients in lanes perpendicular to the antigen lanes; 3) incubation of the membrane with a peroxidase-conjugated second antibody; 4) detection of positive reactions by enhanced chemiluminescence . Emitted light was captured on a photographic film in which the positive reactions appeared as squares at the intersections of antigens with appropriate antibody . Antibody was quantified using a laser densitometer to compare the signal intensity of unknown samples with the ones generated by known amounts of human immunoglobulin captured on the same membrane . The assay permitted simultaneous screening and/or quantification of antibody in as many as 45 serum samples against up to 45 bacterial species . The mean and standard error of the coefficients of variation for replicates within an assay averaged 7.3 +/- 2.3% . Coefficients of variation of the assay run on different days for serum antibody to a range of subgingival species averaged 10.1 +/- 2.1% . Checkerboard immunoblotting is a simple and rapid immunoassay to permit quantification and/or screening of antibody to multiple subgingival species or antigens in multiple serum samples.

Oral Microbiol Immunol, 1996 Dec, 11(6), 402 - 6
Adhesion of Porphyromonas gingivalis fimbriae to human gingival cell line Ca9-22; Hirose K et al.; In this study, we examined the effects of selected environmental factors on the adhesion of Porphyromonas gingivalis fimbriae, an important structure involved in attachment of the bacteria to human gingival cells . The human gingival carcinoma cell line Ca9-22 was grown in microculture plates, and adherence was detected by use of 125I-labeled fimbriae . Adhesion was increased by changes in pH from 7.0-8.0, but was decreased by increase in the sodium chloride concentration above 0.15 M . Trypsin treatment of Ca9-22 cells also augmented adhesion of the fimbriae to the cells . These results indicate that fimbrial adhesion to gingival cells is controlled by various environmental factors, and the data on trypsin treatment suggest that elevated levels of protease in the gingival sulcus, such as can occur with poor oral hygiene and gingivitis, may expose adhesion molecules on the gingival cell surface, thereby promoting the attachment of P . gingivalis fimbriae.

Oral Dis, 1997 Sep, 3(3), 167 - 71
Priming response to inflammatory mediators in hyperreactive peripheral neutrophils from adult periodontitis; Gustafsson A et al.; OBJECTIVES: To study the response to in vitro priming of peripheral neutrophils from patients with periodontitis compared to healthy controls . Peripheral neutrophils from these patients had shown increased production of oxygen radicals after activation with opsonized bacteria and a difference in priming response could suggest an explanation for this hyperreactivity . MATERIALS AND METHODS: Peripheral neutrophils from a group of patients with periodontitis and from age- and sex-matched controls were preincubated with tumor necrosis factor alpha, lipopolysaccharide (LPS), formyl-methionyl-leucyl-phenylalanine and the tetra peptide arginyl-glycyl-aspartate-serine . After preincubation, the cells were activated with gammaglobulin opsonized-bacteria, i.e., a Fc gamma R-stimulation . The priming effect was assessed as the production of oxygen radicals and as the degranulation or primary granules . RESULTS: Showed that the patients had a slightly lower responsiveness to priming than had the controls . This difference in priming response was most pronounced when measured as degranulation of primary granules after preincubation with LPS and 20 min of activation . CONCLUSIONS: This study shows no difference in response to priming, with optimal concentrations of inflammatory mediators, between peripheral neutrophils from patients with adult periodontitis and healthy controls.

Ann Univ Mariae Curie Sklodowska {Med}, 1996, 51, 195 - 202
{Reactions of 1-(X-benzoyl)-4-R-thiosemicarbazide with chloroacetone and omega-bromoacetophenone . VI . 4-(o-tolyl)-thiosemicarbazide of o-nitro - and p-nitrobenzoic acid}; Bielak E et al.; The reactions of 4-(o-tolyl)-thiosemicarbazide of o-nitro- and p-nitrobenzoic acid (Ik, l) with chloroacetone and omega-bromoacetophenone were investigated in: methanolic medium (method D); methanolic medium in the presence of anhydrous CH3COONa (method E); methanolic medium in the presence of N(C2H5)3 (method F) . The properties of compounds IIu-y and IIIu-y were determined under the conditions of basic and acidic hydrolysis . The results of UV, IR and NMR spectroscopic measurements were reported.

J Mol Biol, 1998 Jan 16, 275(2), 337 - 46
Crystal structure of the cyanobacterial metallothionein repressor SmtB: a model for metalloregulatory proteins; Cook WJ et al.; SmtB from Synechococcus PCC7942 is a trans-acting dimeric repressor that is required for Zn(2+)-responsive expression of the metallothionein SmtA . The structure of SmtB was solved using multiple isomorphous replacement techniques and refined at 2.2 A resolution by simulated annealing to an R-factor of 0.218 . SmtB displays the classical helix-turn-helix motif found in many DNA-binding proteins . It has an alpha + beta topology, and the arrangement of the three core helices and the beta hairpin is similar to the HNF-3/fork head, CAP and diphtheria toxin repressor proteins . Although there is no zinc in the crystal structure, analysis of a mercuric acetate derivative suggests a total of four Zn2+ binding sites in the dimer . Two of these putative sites are at the opposite ends of the dimer, while the other two are at the dimer interface and are formed by residues contributed from each monomer . The structure of the dimer is such that simultaneous binding for both recognition helices to DNA would require either a bend in the DNA helix or a conformational change in the dimer . The structure of Synechococcus SmtB is the first in this family of metal-binding DNA repressors.

J Clin Microbiol, 1998 Feb, 36(2), 585 - 6
Quality control limits for dilution and disk diffusion susceptibility tests of trovafloxacin against eight quality control strains; Fuchs PC et al.; A 10-laboratory collaborative effort was designed to generate data to propose quality control limits for susceptibility tests of trovafloxacin . Broth microdilution, agar dilution, and disk diffusion tests were evaluated with eight different control strains . All tests were reproducible, and control limits are proposed.

J Clin Microbiol, 1998 Feb, 36(2), 443 - 8
Improved diagnostic PCR assay for Actinobacillus pleuropneumoniae based on the nucleotide sequence of an outer membrane lipoprotein; Gram T et al.; The gene (omlA) coding for an outer membrane protein of Actinobacillus pleuropneumoniae serotypes 1 and 5 has been described earlier and has formed the basis for development of a specific PCR assay . The corresponding regions of all 12 A . pleuropneumoniae reference strains of biovar 1 were sequenced . Alignment of the sequences revealed conserved terminal and variable middle regions, which divided the reference strains into four distinct groups . Primers were selected from the conserved 5' and 3' termini of the gene . A 950-bp amplicon was obtained from each of 102 tested field isolates of A . pleuropneumoniae obtained from lungs . Their identity was verified by sequencing approximately 500 bp of the amplification product from 50 of the A . pleuropneumoniae isolates, which all showed the expected DNA sequence characteristic of the serotype . To test the specificity of the reaction, 23 other bacterial species related to A . pleuropneumoniae or isolated from pigs were assayed . They were all found negative in the PCR, as were tonsil cultures from 50 pigs of an A . pleuropneumoniae-negative herd . The sensitivity assessed by agarose gel analysis of the PCR product was 10(2) CFU/PCR test tube . The specificity and sensitivity of this PCR compared to those of culture suggest the use of this PCR for routine identification of A . pleuropneumoniae.

Eur J Clin Invest, 1997 Dec, 27(12), 1030 - 7
Oxidative autoaggression by phagocytes in human peritonitis; Billing AG et al.; In 60 abdominal exudates from patients with the diagnosis of either acute or persistent (chronic) peritonitis, indicators of phagocyte-derived oxidative systems (myeloperoxidase, chemiluminescence) and proteases (elastase) were measured . These exudates reveal a picture of maximal inflammatory activation . Both types of exudates (30 each) showed a significant influx of inflammatory cells, with the mean leucocyte count being 73,000 microL and 32,000 microL-1 respectively . Local myeloperoxidase concentrations were approximately 1000-fold greater than that of normal plasma . Spontaneous and elicitable chemiluminescence--indicators of phagocyte respiratory burst activity--were dramatically increased . In addition, levels of extracellularly released elastase (from neutrophils) were found to be up to about 1000-fold that of normal plasma values . Although most of the elastase detected in the exudates was complexed with alpha 1-proteinase inhibitor (alpha 1 PI), enzymatically active elastase could be measured in approximately 60% of the samples being investigated . As there was an excess of immunoreactive alpha 1 PI in these exudates, the free elastase activity implies that much of the alpha 1 PI was inactive, presumably subjected to oxidative destruction . Moreover, a trypsin-inhibitory activity to antigen ratio below 1 (mean = 0.81) in 75% of the purulent exudates indicated also partial proteolytic degradation of alpha 1 PI . In contrast, 16 clear exudates (no bacteria, white cell count below 500 microL-1) taken from the non-infected peritoneal cavity of patients undergoing intra-abdominal surgery revealed a similar permeability increase of the peritoneum but did not show relevant oxidative and proteolytic activity or destruction of alpha 1 PI compared with purulent specimens . Thus, only the inflammatory process of peritonitis appears to result in an overwhelming local phagocytic activity that initiates and maintains protease inhibitor consumption and/or inactivation . The tremendous oxidative potential found in purulent exudates may cause destruction in a wide variety of defence systems.

Zentralbl Veterinarmed A, 1997 Dec, 44(9-10), 595 - 601
Hydrocephalus with periventricular encephalitis in the dog; Cantile C et al.; A 3-month-old female Dalmatian dog and a 2.5-month-old Poodle dog were referred with a sudden onset of neurological syndrome consistent with hydrocephalus . Clinical signs included depression, severe ataxia, eye abnormalities and skull enlargement in one case . Postmortem examination revealed severe internal hydrocephalus with cavitation of the cerebral white matter associated with necrotizing and inflammatory lesions of the periventricular nervous tissue . Although no bacteria were isolated from cerebrospinal fluid and no infectious agents were detected in the brains, an infectious etiology was postulated.

Eur J Immunol, 1997 Dec, 27(12), 3461 - 70
Induction of interleukin-12 p40 transcript by CD40 ligation via activation of nuclear factor-kappaB; Yoshimoto T et al.; Interleukin-12 is produced in response to infection with bacteria or parasites or to bacterial constituents such as LPS in monocytes/macrophages and dendritic cells, and also generated by the interaction between activated T cells and antigen-presenting cells via CD40-CD40 ligand (CD40L) . So far, transcriptional analyses of p40 have been carried out only using bacterial constituents such as LPS as stimuli . In the present study, we have characterized the transcriptional induction of p40 by CD40 ligation in a human B lymphoblastoid cell line, Daudi, and a human acute monocytic leukemia cell line, THP-1 . These cells, stimulated by an agonistic monoclonal antibody against CD40 or by transfection with a CD40L expression vector, secreted p40 and showed enhanced p40 mRNA expression . Sequence analysis of the p40 promoter region identified two potential nuclear factor (NF)-kappaB binding sites conserved between mouse and human . Electrophoretic mobility shift assay revealed that the potential NF-kappaB binding sequence which is located around 120 bp upstream of the transcription initiation site in murine and human p40 genes formed an NF-kappaB complex with nuclear extract from Daudi cells stimulated by CD40 ligation . Moreover, transfection of Daudi cells with the polymerized NF-kappaB binding sequence ligated to a thymidine kinase/chloramphenicol acetyltransferase (CAT) reporter plasmid greatly induced CAT activity, but transfection with the polymerized mutated NF-kappaB binding sequence did not . These results suggest that the NF-kappaB binding site located around 120 bp upstream of the transcription initiation site in murine and human p40 promoter regions could be important for the p40 induction by CD40 ligation via activation of NF-kappaB.

Appl Environ Microbiol, 1998 Feb, 64(2), 613 - 7
The use of fluorogenic substrates to measure fungal presence and activity in soil; Miller M et al.; Our objective was to determine if 4-methylumbelliferyl-labelled enzyme substrates could be used to detect and quantify specific components of chitinase and cellulase activities as specific indicators of the presence and activity of fungal biomass . The fluorogenic substrates 4-methylumbelliferyl (MUF) N-acetyl-beta-D-glucosaminide and MUF beta-D-lactoside were used for the detection and quantification of beta-N-acetylglucosaminidase (EC 3.2.1.30) (NAGase) and endo 1,4-beta-glucanase (EC 3.2.1.4)/cellobiohydrolase (EC 3.2.1.91) (CELase), respectively . Culture screenings on solid media showed a widespread ability to produce NAGase among a taxonomically diverse selection of fungi on media with and without added chitin . NAGase activity was expressed only in a limited number of bacteria and on media supplemented with chitin . The CELase activity was observed only in a limited number of fungi and bacteria . Bacterial CELase activity was expressed on agar media containing a cellulose-derived substrate . In soil samples, NAGase activity was significantly correlated with estimates of fungal biomass, based on the content of two fungus-specific indicator molecules, 18:2 omega 6 phospholipid fatty acid (PLFA) and ergosterol . CELase activity was significantly correlated with the PLFA-based estimate of fungal biomass in the soil, but no correlation was found with ergosterol-based estimates of fungal biomass.

J Nat Prod, 1998 Jan, 61(1), 116 - 8
Purine and nucleoside metabolites from the Antarctic sponge Isodictya erinacea; Moon B et al.; The bright yellow sponge Isodictya erinacea is one of several chemically defended sponges found on the benthos of McMurdo Sound, Antarctica . An investigation of the metabolites from this sponge has resulted in the isolation of purine and nucleoside metabolites, including the previously unreported erinacean (1) and p-hydroxybenzaldehyde . The latter metabolite has been demonstrated to cause a feeding deterrence behavior in Perknaster fuscus, the major predator of antarctic sponges.

Biochemistry (Mosc), 1997 Oct, 62(10), 1103 - 8
Ether lipids and platelet-activating factor: evolution and cellular function; Kulikov VI et al.; This review considers the relation between the evolution of ether lipids and platelet-activating factor (PAF) in living organisms for the first time . Ether lipids are shown to be the main structural lipid components in the cells of the most primitive organisms on the Earth; during evolution they were gradually substituted for lipids with ester and vinyl bonds . Synthesis of PAF has been found in some bacteria, protozoans, yeasts, plants, marine invertebrates, lower vertebrates, and mammals . The regulatory role of PAF is suggested to already appear in protozoans and later be maintained during the subsequent evolution of living organisms . During evolution, functions of PAF in the cell have been changing and enlarging, while ether lipids have been gradually losing their role as the main structural lipid component of the cells of living organisms.

Gene, 1998 Jan 5, 206(1), 99 - 105
The mRNA for GST Pi from FRHK rhesus monkey kidney cells codes for an enzyme with activity towards 1-chloro-2,4-dinitrobenzene in spite of an I68F mutation; Swedmark S et al.; A cDNA library was constructed from mRNA of the rhesus monkey kidney cell line, FRHK, and the cDNA sequence for an FRHK glutathione S-transferase (GST) Pi was determined using a RACE method . This represents the first full-length monkey GST Pi sequence to be cloned and determined . The similarity to the human GST Pi was found to be extensive (more than 97%), the deduced protein differing only in six amino acids (aa) positions . FRHK GST Pi was expressed in bacteria and a recombinant protein was purified which demonstrated significant activity towards the substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 1,2-epoxy-3-para-nitrophenoxypropane . Western blots also showed significant amounts of protein, both in the FRHK cells and transformed bacteria . The FRHK GST Pi was found to contain a phenylalanine at aa position 68, a position which is otherwise invariably occupied by an isoleucine in the GST Pi, Alpha, Mu and Beta class enzymes investigated . An isoleucine in this position is thus not essential for activity in the FRHK enzyme, unlike the human GST pi, where the exchange of Ile68 to a tyrosine (Manoharan, T.H, Gulick, A.M., Puchalski, R.B., Servais, A.L., Fahl, W.E., 1992 . J . Biol . Chem., 267, 18940-18945), resulted in total loss of activity . Phe68 was mutated to Ile in the FRHK GST Pi enzyme to determine whether the wild type amino acid conferred an impaired catalytic site . The resulting mutant did not show any changes in activity towards CDNB, clearly demonstrating that isoleucine at position 68 is not essential . Thus, the first monkey GST Pi enzyme has been characterized, an enzyme with many similarities to the human forms although it differs in an otherwise conserved residue at aa position 68 . This difference does not appear to affect the function of the FRHK GST Pi.

Gene, 1997 Dec 31, 205(1-2), 103 - 7
CpG distribution patterns in methylated and non-methylated species; Shimizu TS et al.; To characterize the extent of DNA methylation and its possible biological roles in a wide variety of organisms, we have analyzed gene sequences extracted from the GenBank database . Sequences of both methylated and non-methylated species were used for comparative analysis . The local CpG dinucleotide distribution near the 5' ends of genes as well as the degree of overall CpG suppression/depletion in the entire gene region were examined in all complete gene sequences for each species . We show that the distribution patterns of CpG near the 5' region of genes differ among vertebrates, invertebrates, plants and bacteria . CpG island-like peaks in CpG O/E (observed/expected ratio) were observed not only in methylated species, but also in non-methylated species . In methylated non-vertebrates, overall CpG O/E values were lower, and peaks in the CpG profile of 5' regions were larger than in non-methylated species . We discuss the implications of such biases with respect to DNA methylation.

Biol Chem, 1997 Dec, 378(12), 1413 - 9
The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase: biochemistry, structure, occurrence and evolution; Habenicht A; The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase catalyses the irreversible reaction of glyceraldehyde-3-phosphate to 3-phosphoglycerate by the reduction of NADP to NADPH . This is in contrast to the extensively analysed phosphorylating glyceraldehyde-3-phosphate dehydrogenases which catalyse the reversible reaction of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate . Sequence analysis revealed that the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase is not related to the phosphorylating glyceraldehyde-3-phosphate dehydrogenases but a member of the aldehyde dehydrogenase superfamily . The aldehyde dehydrogenases are of ancient origin and they have already existed in the progenote as indicated by phylogenetic analysis . Thus the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase can be found in all three domains, archaea, bacteria and eukarya . The catalytic mechanism of the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase and the other aldehyde dehydrogenases resembles a thioester mechanism involving the universally conserved cysteine 298 (pea GAPN) . The cofactor of the aldehyde dehydrogenases is bound in a new mode to a structure described as beta-alpha,beta-fold.

Perspectives, 1997 Winter, 21(4), 15 - 6
Wound cleaning versus wound disinfection: a challenging dilemma; Phillips D et al.; Our experience with this resident has had a significant impact on our approach to wound management . We no longer accept normal saline as the only option for wound cleansing . Instead, we approach wound cleansing systematically using the wound cleansing model outlined in Figure 1 . If healing is not apparent, we critically review the situation and consider the bacterial status of the wound, the phase of wound healing, and the effects of wound cleansing versus wound disinfection on both the bacteria and the cells responsible for wound repair . In infected wounds or those colonized with a high bacterial count, careful attention is given to eradicating bacterial contamination . We carefully weigh the benefits of wound disinfection (eradication of bacterial contamination) against wound cleansing and the potential harm to the resident (delayed wound healing and unnecessary discomfort) . If the benefits of wound disinfection outweigh the potential harm to the resident, we choose wound disinfection and monitor its effectiveness on a daily basis . When bacterial contamination has been eradicated and the wound is clean, we resume wound cleansing with normal saline.

Hum Reprod Update, 1997 Jul-Aug, 3(4), 301 - 10
Fertility regulating and immunotherapeutic vaccines reaching human trials stage; Talwar GP; The progress and current status of vaccines which induce antibodies against human chorionic gonadotrophin (HCG) and luteinizing hormone-releasing hormone (LHRH) are reviewed . Three vaccines devised against HCG have undergone phase I clinical trials documenting their safety, and reversibility . One of these, the heterospecies dimer (HSD)-HCG vaccine has also completed phase II efficacy trials in sexually active women of proven fertility . Immunization with the vaccine prevents pregnancy, as long as the antibody titres remain > or =50 ng/ml HCG bioneutralization capacity . There is no disturbance of menstrual regularity and women continue to ovulate normally . The antibody response is predominantly against an epitope in the core part of beta-HCG . Fertility is regained at titres <35 ng . These observations have laid the scientific foundations of a birth control vaccine . Research suggests the feasibility of making a cost-effective recombinant vaccine . The carriers tetanus toxoid (TT) and diptheria toxoid (DT) can be advantageously replaced by peptide determinants recognizing T, not B cells . In addition to optional fertility control, HCG vaccines may have tumour growth inhibition potential in lung cancers which produce HCG . The vaccine against LHRH can be used in both males and females . As it is a structurally conserved molecule, the same vaccine is applicable to both animals and humans . Antibodies against LHRH block the generation of gametes and sex steroids, with the result that the vaccine can be used for fertility control (domestic pets, prolongation of lactation amenorrhoea); as well as for sex hormone-dependent cancers . Phase I/phase II clinical trials have been conducted with the LHRH vaccine in advanced metastazing carcinoma of prostate patients with encouraging results . Bioeffective monoclonal antibodies have been developed against both LHRH and HCG . These can be 'humanized' and produced cost-effectively in bacteria and plants, thus paving the way for passive use of such antibodies for immunotherapy of cancers and fertility control.

J Crit Care, 1997 Dec, 12(4), 193 - 9
Study of some phagocyte membrane receptors in patients receiving intravenous polyvalent immunoglobulins as adjunct treatment for nosocomial pneumonia; Martin C et al.; PURPOSE: Phagocytosis is a major mechanism of defense against bacterial infections . The ingestion of bacteria by phagocytes involves a variety of cell membrane recognition structures and, among them, immunoglobulin receptors . The aim of this study was to test the phagocytic activity of granulocytes and monocytes of intensive care unit (ICU) patients, and to evaluate the effects of intravenous polyvalent immunoglobulins (IVIG) used as adjunct treatment of nosocomial pneumonia on some phagocyte membrane receptors of these patients . MATERIALS AND METHODS: The phagocytic activity of granulocytes and monocytes of 41 mechanically ventilated patients with nosocomial bacterial pneumonia was studied during the acute phase of infection . These ICU patients were compared with 21 hospitalized, noninfected volunteer patients hospitalized in a medical ward . Peripheral blood granulocytes and monocytes were studied . Of the 41 ICU patients, after randomization, 21 received IVIG at a dose of 1 g/kg for 3 days . The 41 ICU patients were compared with the 21 non-ICU, noninfected hospitalized controls . The 21 ICU patients who received 3 days of IVIG were also compared with the 20 ICU patients not receiving IVIG . Cells were tested in standard immunoglobulin-free medium (fetal calf serum) and in the presence of patients' serum . Blood granulocytes and monocytes were purified and separately exposed to three types of particles: antibody-coated erythrocytes (to test immunoglobulin receptors), opsonized zymosan (to test C3 receptors), and glutaraldehyde-treated erythrocytes (to test lectinlike or other nonspecific binding sites) . Phagocytosis and superoxide anion production (oxidative burst) were measured . RESULTS: Granulocytes of ICU patients compared with those of non-ICU, noninfected patients exhibited a substantial decrease of zymosan ingestion (P < .05), whereas phagocytosis of other particles was normal . Monocytes from the ICU patients, compared with those of the non-ICU, noninfected patients, displayed an unselective overall decrease of phagocytic ability for the three particle types (P < .05) . The phagocytosis activity of the three membrane receptor species of blood monocytes and granulocytes of ICU patients was not significantly modified by the IVIG infusion . For both monocytes and granulocytes, no significant improvement was observed in the fraction of cells that ingested at least one foreign particle and the mean number of particles per cell having phagocytized at least one foreign particle . Granulocyte and monocyte functions were also tested by the production of reduced ferricytochrome and no significant improvement in the oxidative burst was observed after infusion of IVIG . CONCLUSION: Infected ICU patients display a deficiency of phagocytosis membrane receptors of blood granulocytes and monocytes . The addition of IVIG to standard therapy does not improve the phagocytic activity of ICU patients with nosocomial pneumonia.

Z Gastroenterol, 1997 Oct, 35(10), 929 - 34
{Sclerosing cholangitis after burn injury}; Schmitt M et al.; We present the case of a 57-year-old woman who developed persistent jaundice and cholestasis four weeks after a severe burn injury (34% of the body surface, 19% second degree, 15% third degree) . In the endoscopic retrograde cholangiography four months later the characteristic picture of sclerosing cholangitis was found . A causal relation between the thermal injury and the development of sclerosing cholangitis is likely because of this coincidence and the absence of any preexisting disease, especially of the hepatobiliary system . Other cholestatic liver disease could be excluded . Possible pathogenetic mechanisms are discussed, especially the increased permeability of the gut mucosa after burn injuries with consecutive translocation of bacteria and toxins and their transport into the biliary tract.

Int J Tuberc Lung Dis, 1997 Aug, 1(4), 370 - 6
Restriction fragment length polymorphism study of Mycobacterium tuberculosis in Thailand using IS6110 as probe; Palittapongarnpim P et al.; SETTING: Three referral hospitals in central Thailand . OBJECTIVE: To determine the population structure of Mycobacterium tuberculosis isolated from the referral hospitals . DESIGN: Study of 211 isolates of the bacteria received from the hospitals in central Thailand by Southern hybridization, with IS6110 probe and other probes when indicated . RESULTS: In 43 isolates only one copy of IS6110 was observed . These could be further differentiated by DR- and PGRS-specific probes . Two large groups of isolates with similar hybridization patterns were identified . The Beijing family, comprising 80 isolates, was previously reported to be commonly found in China, Mongolia, Thailand and Korea . The Nonthaburi group, comprising 29 isolates, were local strains . The age, sex and HIV status of the patients did not significantly correlate with the chance of being infected by isolates of any particular hybridization pattern . However, clustered isolates were found more commonly among the members of both the Beijing family and the Nonthaburi group . CONCLUSION: Southern hybridization with IS6110 was found to be useful in studying the epidemiology of tuberculosis in Thailand . The existence of the Beijing family was confirmed . The unusually wide spread of the Beijing family in several countries in Asia merits further investigation.

Pediatr Res, 1998 Jan, 43(1), 84 - 90
Butyrate enhances interleukin (IL)-8 secretion by intestinal epithelial cells in response to IL-1beta and lipopolysaccharide; Fusunyan RD et al.; Intestinal epithelial (Caco-2) cells secrete the chemokine, IL-8, after stimulation with IL-1beta, but not after lipopolysaccharide . Butyrate is a short chain fatty acid derived from the metabolism of intestinal contents by gut bacteria . Butyrate concentrations reflect, therefore, the bacterial microenvironment established within the intestine . We hypothesized that butyrate may alter the secretion of IL-8 by intestinal epithelial cells in response to stimulation by IL-1beta or lipopolysaccharide . Caco-2 cells were incubated in varying concentrations of sodium butyrate (0-20 mM) for 24 h before stimulation with lipopolysaccharide or IL-1beta . IL-8 secretion was measured over 24 h by ELISA . IL-8 mRNA accumulation was detected by Northern blots . Lipopolysaccharide induced the secretion of IL-8 only after Caco-2 cells cells had been cultured with sodium butyrate . Furthermore, butyrate significantly enhanced IL-8 secretion by cells stimulated with IL-1beta . Butyrate also increased IL-8 mRNA accumulation in stimulated Caco-2 cells . Intestinal epithelial cells can, therefore, be primed by butyrate to become activated by lipopolysaccharide and proinflammatory cytokines . This may represent a mechanism by which intestinal epithelial cells can regulate intestinal inflammation in response to changes in the intestinal milieu.

J Clin Microbiol, 1998 Jan, 36(1), 251 - 4
Development of an immunomagnetic method for selective isolation of Actinobacillus pleuropneumoniae serotype 1 from tonsils; Gagne A et al.; An immunomagnetic separation technique (IMS) for the selective isolation of Actinobacillus pleuropneumoniae serotype 1 was developed . Superparamagnetic polystyrene beads (immunomagnetic beads {IMBs}) were coated with purified rabbit immunoglobulin G specific for A . pleuropneumoniae serotype 1 . The antibody concentration, the number of IMBs, the incubation time, and the temperature of incubation influenced the recovery of the target bacteria . The sensitivity of the IMS technique was 1,000-fold higher than that of direct culture . When tonsils from animals from infected herds were tested, significantly more positive tonsils were detected by the IMS technique (68%) than by the standard procedures (22%) . The method represents an innovative and highly sensitive approach for the isolation of A . pleuropneumoniae from carrier animals.

Heart Lung, 1997 Nov-Dec, 26(6), 419 - 29
Ventilator-associated pneumonia: clinical significance and implications for nursing; Grap MJ et al.; Pneumonia is the second most common nosocomial infection in the United States and the leading cause of death from nosocomial infections . Intubation and mechanical ventilation greatly increase the risk of bacterial pneumonia . Ventilator-associated pneumonia (VAP) occurs in a patient treated with mechanical ventilation, and it is neither present nor developing at the time of intubation; it is a serious problem--with significant morbidity and mortality rates . Aspiration of bacteria from the oropharynx, leakage of contaminated secretions around the endotracheal tube, patient position, and cross-contamination from respiratory equipment and health care providers are important factors in the development of VAP . Nurses caring for patients treated with mechanical ventilation must recognize risk factors and include strategies for reducing these factors as part of their nursing care . This article summarizes the literature related to VAP: its incidence, associated factors, diagnosis, and current therapies, with an emphasis on nursing implications in the care of these patients.

J Reprod Immunol, 1997 Nov 30, 36(1-2), 93 - 109
Pre-term labor: an intra-uterine inflammatory response syndrome?
Dudley DJ.
Emerging concepts of sepsis suggest that the host response to an infectious stimulus results in some cases of uncontrolled release of inflammatory cytokines leading to signs of sepsis . Systemic inflammatory response syndrome (SIRS) has been suggested as a diagnosis when no etiologic organism can be found . Infection may account for up to 30% of cases of pre-term labor, and may either be clinically-evident or sub-clinical . Inflammatory cytokines can be detected in elevated concentrations in the amniotic fluid and plasma of women with pre-term labor, and human gestational tissues are potentially rich sources of inflammatory cytokines, as found in in vivo and in vitro studies . Also, maternal decidua and fetal membranes produce mRNA for inflammatory cytokines in the setting of infection-associated pre-term labor and normal term labor . Notably, anti-inflammatory cytokines, such as interleukin-10 (IL-10) do not appear to be present in substantial quantities in these pathophysiologic and physiologic conditions . Animal models indicate that pre-term labor can be stimulated by bacteria, bacterial cell wall products, and inflammatory cytokines such as IL-1 and tumor necrosis factor . These findings suggest that: (1) infectious stimuli may result in the liberation of inflammatory cytokines from gestational tissues leading inevitably to pre-term labor and delivery; (2) inhibition of this process may either be overcome or abrogated, and (3) the mechanisms regulating cytokine production in maternal and fetal tissues are disturbed . Thus, pre-term labor associated with sub-clinical infection may result in a dysregulated local inflammatory response, in which the maternal host response causes an 'intra-uterine inflammatory response syndrome' leading to pre-term labor and delivery.

Methods, 1997 Oct, 13(2), 112 - 22
Tagging genes and trapping promoters in Toxoplasma gondii by insertional mutagenesis; Roos DS et al.; Plasmid vectors that incorporate sequence elements from the dehydrofolate reductase-thymidylate synthase (DHFR-TS) locus of Toxoplasma gondii integrate into the parasite genome with remarkably high frequency (>1% of transfected parasites) . These vectors may-but need not-include mutant DHFR-TS alleles that confer pyrimethamine resistance to transgenic parasites . Large genomic constructs integrate at the endogenous locus by homologous recombination, but cDNA-derived sequences lacking long stretches of contiguous genomic DNA (due to intron excision) typically integrate into chromosomal DNA by nonhomologous recombination . Nonhomologous integration occurs effectively at random; and coupled with the high frequency of transformation, this allows a large fraction of the parasite genome to be tagged in a single electroporation cuvette . Genomic tagging permits insertional mutagenesis studies conceptually analogous to transposon mutagenesis in bacteria, yeast, Drosophila, etc . In theory (and, thus far, in practice), this allows identification of any gene whose inactivation is not lethal to the haploid tachyzoite form of T . gondii and for which a suitable selection or screen is available . Transformation vectors can be engineered to facilitate rescue of the tagged locus and to include a variety of reporters or selectable markers . Genetic strategies are also possible, using reporters whose function can be assayed by metabolic, visual, or immunological screens to "trap" genes that are activated (or inactivated) under various conditions of interest .

Chem Biol, 1995 Aug, 2(8), 553 - 61
Determination of the structure of exochelin MN, the extracellular siderophore from Mycobacterium neoaurum; Sharman GJ et al.; BACKGROUND: Siderophores are compounds produced by bacteria to acquire iron . Exochelin MN, the extracellular siderophore from Mycobacterium neoaurum, is of particular interest because it has been shown to transport iron into M . leprae, which is responsible for the disease leprosy . Exochelins from other species cannot mediate iron transport in M . leprae, suggesting a specific uptake mechanism involving exochelin MN . We set out to determine the structure of exochelin MN and identify the features of the molecule that may account for this specificity . RESULTS: The structure of exochelin MN was elucidated by a combination of techniques including nuclear magnetic resonance, mass spectrometry, derivatization and gas chromatography . Exochelin MN is a peptide, containing the unusual amino acid beta-hydroxyhistidine and an unusual N-methyl group . The peptide coordinates iron(III) octahedrally using its two cis-hydroxamate groups plus the hydroxyl and imidazole nitrogen of the beta-hydroxyhistidine . The three-dimensional structure of the hexadentate exochelin/gallium complex was deduced from NMR data . CONCLUSIONS: Exochelin MN has some structural features in common with other siderophores, but has a unique three-dimensional structure, which is presumably important for its specific activity in M . leprae . Exochelin MN may be a target for drug design in the fight against infection with this pathogen.

Fold Des, 1997, 2(5), R71 - 9
Transmuting alpha helices and beta sheets; Dalal S et al.; Protein architecture involves two main secondary structural classes: alpha helices and beta sheets . Some natural proteins alter their fold in response to changes in solution conditions or as a consequence of mutation . Here, we discuss recent attempts to induce such conformational changes by design: specifically, the motivation and success of efforts to change one protein fold into a different one in response to the 'Paracelsus Challenge' . The results of such efforts may provide a better understanding of the processes that underlie conformational plasticity in proteins.

Zentralbl Hyg Umweltmed, 1997 Apr, 199(6), 568 - 77
{Establishment of a method for determining the association between Legionella sp . and Amoeba sp . using polymerase chain reaction}; Pabst U et al.; With two pairs of primers for the amplification of the MIP- (macrophage infectivity potentiator) and the 5S rDNA-fragment, it was possible to establish a DNA extraction and a PCR method for the detection of Legionella sp . in water-samples and, after cultivation, in Amoeba sp . Therefore, water-samples from a warm water-system in a hospital were taken . In all samples, legionellae were detected by the PCR method and identified by cultivation and a direct immunofluorescence-method as L . pneumophila (serogroup 1) . Legionellae and amoebae of the same water sample were cocultured . Legionellae were also adherent at the outer-membrane . To separate the amoebae from the legionellae, the amoebae were sedimented selectively by centrifugation at 200 x g . This washing procedure had to be repeated seven times in order to eliminate the extraamoebale legionellae for sure . After DNA-extraction of water samples and heat treatment of the intraamoebale legionellae respectively, the amplification was performed with the MIP- and 5S rDNA-primers . In 14 of 16 cocultivations growth of legionellae was found . This result and the detection of legionellae and amoebae in the same water samples suggest that an infection of amoebae may also take place in the water system of the hospital . This is important for the disinfection as a procedure to eliminate legionellae, since intraamoebale bacteria are more resistant to environmental manipulation . Because in two of the cocultivations no growth of legionellae in amoebae was found, it can be assumed that only specific subtypes of legionellae can infect amoebae species.

Mol Cell Probes, 1997 Oct, 11(5), 323 - 8
DNA-probes for the differentiation of Capnocytophaga species; Conrads G et al.; We designed oligonucleotides to differentiate between the seven currently known Capnocytophaga species . The oligonucleotides were labelled non-radioactively at the 3' end with digoxigenin . The specificity could be demonstrated in a dot-blot hybridization assay by using the type strains, reference strains, and 37 clinical Capnocytophaga isolates as well as 11 representative strains of other taxa as a template . The sensitivity of the assay was calculated with 10(3) bacteria per dot.

J Mol Biol, 1997 Nov 7, 273(4), 826 - 39
The interaction of the F plasmid killer protein, CcdB, with DNA gyrase: induction of DNA cleavage and blocking of transcription; Critchlow SE et al.; We have studied the interaction of the F plasmid killer protein CcdB with its intracellular target DNA gyrase . We confirm that CcdB can induce DNA cleavage by gyrase and show that this cleavage reaction requires ATP hydrolysis when the substrate is linear DNA, but is independent of hydrolysis when negatively supercoiled DNA is used . The 64 kDa domain of the gyrase A protein, which can catalyse DNA cleavage in the presence of the B protein and quinolone drugs, is unable to cleave DNA in the presence of CcdB unless the C-terminal 33 kDa domain of the gyrase A protein is also present . CcdB-induced DNA cleavage by gyrase requires a minimum length of DNA (> approximately 160 bp), whereas in the presence of quinolone drugs gyrase can cleave much shorter DNA molecules . We show that CcdB, like quinolones, can form a complex with gyrase which can block transcription by RNA polymerase . A model for the interaction of CcdB with gyrase involving the trapping of a post-strand-passage intermediate is suggested . We conclude that CcdB can stabilise a cleavage complex between DNA gyrase and DNA in a manner distinct from quinolones but, like the quinolone-induced cleavage complex, the CcdB-stabilised complex can also form a barrier to the passage of polymerases.

Vet Clin North Am Small Anim Pract, 1997 Nov, 27(6), 1523 - 36
Ear disease and its management; McKeever PJ et al.; Tissue changes, diseases or factors predisposing to, bacteria and yeast associated with, diagnosis of, and management of otitis externa, media, and interna are discussed in this article.

J Bacteriol, 1998 Feb, 180(3), 759 - 61
Contact stimulation of Tgl and type IV pili in Myxococcus xanthus; Wall D et al.; Myxococcus xanthus tgl mutants lack social motility and type IV pili but can be transiently stimulated to swarm and to make pili by contacting tgl+ cells . The absence of pili in tgl mutants is shown not to be due to the absence of pilin . The rate of pilus elongation after Tgl stimulation is shown to be similar to the rate of pilus elongation in wild-type cells, using a new more rapid assay for stimulation.

Cancer J Sci Am, 1997 Dec, 3 Suppl 1, S98 - 105
Inhaled interleukin-2 therapy in pulmonary metastatic renal cell carcinoma: six years of experience; Huland E et al.; PURPOSE: Patients with advanced metastatic renal cell carcinoma often cannot or do not want to tolerate high-dose systemic interleukin-2 (IL-2) therapy and the toxicity associated with it . To reduce toxicity and still maintain or even increase effectiveness, we developed a method to deliver IL-2 locally for the treatment of pulmonary and mediastinal metastases in metastatic renal cell carcinoma patients . PATIENTS AND METHODS: We report here 6 years of experience treating 116 metastatic renal cell carcinoma patients who had pulmonary or mediastinal metastases with inhaled IL-2 . We have utilized three different IL-2 preparations (natural human IL-2 purified from the supernatants of mitogen-activated peripheral blood lymphocytes, glycosylated recombinant IL-2 produced by Chinese hamster ovary cells, and non-glycosylated recombinant IL-2 produced by bacteria) . All protocols used high-dose inhalation of IL-2, either exclusively (11%), with coadministration of low-dose systemic IL-2 (33%), or with coadministration of low-dose systemic IL-2 and interferon-alpha (56%) . RESULTS: Maximal toxicity per total treatment time was mild (median treatment time, 7.2 months); there was a low incidence (16%) of World Health Organization grade 3 toxicity . Toxicity associated with exclusive inhalation of IL-2 was local and consisted mainly of cough . Thus, patients who could not tolerate high-dose systemic IL-2 were able to tolerate inhalation IL-2 therapy . Progressive pulmonary metastases responded in 15% of patients for a median of 15.5 months (range, 4.1-33 months) and were stabilized in 55% of patients for a median of 6.6 months (range, 3-51.7 months) . The overall response rate was 16%; disease was stabilized in 49% of patients and disease progressed in 35% of patients . The overall median response duration was 9.6 months . Median survival was 11.8 months (range, 1.7-68.8 months); expected survival according to risk analysis was 5.3 months . CONCLUSIONS: Inhalation of IL-2 is a nontoxic and effective treatment for patients with progressive pulmonary and mediastinal metastases . Inhaled IL-2 effectively prevented progress of pulmonary metastases in 70% of patients . Furthermore, patients could be treated as outpatients and remain employed . Local administration of IL-2 increases therapeutic effectiveness with little or no toxicity.

Am J Otol, 1998 Jan, 19(1), 7 - 19
Cholesteatoma: a molecular and cellular puzzle; Albino AP et al.; HYPOTHESIS: There are at least three possible molecular models of cholesteatoma pathogenesis . Cholesteatoma may arise as a result of 1) the induction of a preneoplastic or neoplastic transformation event; 2) a defective wound-healing process; and/or 3) a pathologic collision of the host inflammatory response, normal middle ear epithelium, and a bacterial infection . BACKGROUND: There have been a number of speculations concerning the factors that foster the development of cholesteatoma . Before resolving the molecular basis for the pathogenesis of cholesteatomas, it is important to present and test plausible models that could explain how a cholesteatoma becomes invasive, migratory, hyperproliferative, aggressive, and recidivistic . METHODS: The authors evaluated by various techniques (e.g., immunohistochemistry, flow cytometry, and image analysis) a large number of cholesteatomas of all types (e.g., primary and secondary acquired, recurrent, and congenital) and a range of normal tissues (tympanic membrane, canal wall skin, and postauricular skin) for the expression of various proteins (e.g., p53, ectopeptidases, tryptase) and for the presence of DNA aneuploidy . RESULTS AND CONCLUSIONS: The authors' published and unpublished studies to date support several suppositions concerning the pathology of cholesteatomas . First, cholesteatoma epithelium behaves more like a wound-healing process than a neoplasm . The available evidence to date does not indicate that cholesteatomas have inherent genetic instability, a critical feature of all malignant lesions . Second, the induction of hyperproliferative cells in all layers of the cholesteatoma epidermis implicates a potential idiopathic response to both internal events as well as external stimuli in the form of cytokines released by infiltrating inflammatory cells . Third, the presence of bacteria may provide a critical link between the cholesteatoma and the host, which prevents the cholesteatoma epithelium from terminating specific differentiation programs and returning to a quiescent state in which it becomes minimally proliferative, nonmigratory, and noninvasive . Fourth, none of our data suggest that there are any obvious molecular or cellular differences among the various types of cholesteatomas (e.g., primary and secondary acquired, recidivistic, and congenital) . Continued research should delineate the precise molecular and cellular dysfunction involved in the pathogenesis of cholesteatomas and how this knowledge can be useful in the clinical management of cholesteatomas.

Biochemistry, 1998 Jan 27, 37(4), 1076 - 82
The C-terminal half of the anti-sigma factor FlgM contains a dynamic equilibrium solution structure favoring helical conformations; Daughdrill GW et al.; FlgM is the inhibitor of sigma 28, a transcription factor specific for the expression of bacterial flagella and chemotaxis genes . FlgM is also exported from the cytoplasm to the outside of the cell during the process of flagella filament assembly . In the absence of its targets, FlgM is a dynamic, mostly unfolded, molecule {Daughdrill, G . W., et al . (1997) Nat . Struct . Biol . 4(4), 285-291} . The NMR resonance assignments, dynamics, and average secondary structure of this mostly unfolded form of FlgM are reported here . Because of the dynamic behavior of FlgM, the deviation of C alpha chemical shifts from the random coil values was used to test for the presence of secondary structure {Wishart, D . S., and Sykes, B . D . (1994) Methods Enzymol . 239, 363-392} . This analysis shows two contiguous regions in the C-terminal half of FlgM with helical C alpha chemical shifts . These two regions, M60-G73 and A83-A90, contained less than 10 medium-range NOEs, and the 15N relaxation parameters suggest the helical structure is not rigid . However, the C alpha chemical shifts of M60-G73, A83-A90, and other residues in the C-terminal half of FlgM shift toward their canonical random coil values with the addition of a chemical denaturant . Along with the values of the order parameter, S2, this observation suggests the C-terminal half of FlgM exists in an equilibrium structural state that is nonrandom . The same analysis of the N-terminal half of FlgM suggests it more closely resembles a random coil in conditions with and without denaturant . It appears the C-terminal half of FlgM lacks sufficient intramolecular contacts to form stable secondary or tertiary structures . It is known this C-terminal region becomes rigidly held when FlgM binds sigma 28 (Daughdrill et al., 1997), and it is possible that binding stabilizes the helical structure . The potential evolutionary relationship between the inhibitory interaction of FlgM with sigma 28 and the autoinhibition observed in sigma 70 is discussed.

Infect Immun, 1998 Feb, 66(2), 870 - 3
Anti-lipid A monoclonal antibody centoxin (HA-1A) binds to a wide variety of hydrophobic ligands; Helmerhorst EJ et al.; This note describes the binding specificities of four lipid A monoclonal antibodies (MAbs) including Centoxin (HA-1A); these MAbs display similar binding properties . MAbs reacted with lipid A and heat-killed smooth bacteria, whereas no reactivity was observed with smooth lipopolysaccharide (LPS) . Immunoblotting of bacterial extracts separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the MAbs bound to many polypeptide bands including the molecular weight markers . Denaturation of bovine serum albumin (BSA) by boiling or dithiothreitol treatment unmasked antibody epitopes . In addition, binding both to a hydrophobic aliphatic C12 chain covalently coupled to BSA and to single-stranded DNA was observed . The polyreactivity of these clones is most likely mediated by a preferential reactivity with hydrophobic molecular patches.

Infect Immun, 1998 Feb, 66(2), 807 - 14
In vivo formation of electron paramagnetic resonance-detectable nitric oxide and of nitrotyrosine is not impaired during murine leishmaniasis; Giorgio S et al.; Recent studies have provided evidence for a dual role of nitric oxide (NO) during murine leishmaniasis . To explore this problem, we monitored the formation of NO and its derived oxidants during the course of Leishmania amazonensis infection in tissues of susceptible (BALB/c) and relatively resistant (C57BL/6) mice . NO production was detected directly by low-temperature electron paramagnetic resonance spectra of animal tissues . Both mouse strains presented detectable levels of hemoglobin nitrosyl (HbNO) complexes and of heme nitrosyl and iron-dithiol-dinitrosyl complexes in the blood and footpad lesions, respectively . Estimation of the nitrosyl complex levels demonstrated that most of the NO is synthesized in the footpad lesions . In agreement, immunohistochemical analysis of the lesions demonstrated the presence of nitrotyrosine in proteins of macrophage vacuoles and parasites . Since macrophages lack myeloperoxidase, peroxynitrite is likely to be the nitrating NO metabolite produced during the infection . The levels of HbNO complexes in the blood reflected changes occurring during the infection such as those in parasite burden and lesion size . The maximum levels of HbNO complexes detected in the blood of susceptible mice were higher than those of C57BL/6 mice but occurred at late stages of infection and were accompanied by the presence of bacteria in the cutaneous lesions . The results indicate that the local production of NO is an important mechanism for the elimination of parasites if it occurs before the parasite burden becomes too high . From then on, elevated production of NO and derived oxidants aggravates the inflammatory process with the occurrence of a hypoxic environment that may favor secondary infections.

No To Shinkei, 1997 Dec, 49(12), 1161 - 70
{A 62-year-old man with an acute onset of consciousness disturbances}; Koshimura I et al.; We report a 62-year-old man who developed coma and died in a fulminant course . The patient was well until May 1, 1996 when he noted chillness, tenderness in his shoulders, and he went to bed without having his lunch and dinner . In the early morning of May 2, his families found him unresponsive and snoring; he was brought into the ER of our hospital . He had histories of hypertension, gout, and hyperlipidemia since 42 years of the age . On admission, his blood pressure was 120/70, heart rate 102 and regular, and body temperature 36.3 degrees C . His respiration was regular and he was not cyanotic . Low pitch rhonchi was heard in his right lower lung field . Otherwise general physical examination was unremarkable . Neurologic examination revealed that he was somnolent and he was only able to respond to simple questions such as opening eyes and grasping the examiner's hand, but he was unable to respond verbally . The optic discs were flat; the right pupil was slightly larger than the left, but both reacted to light . He showed ptosis on the left side, conjugate deviation of eyes to the left, and right facial paresis . The oculocephalic response and the corneal reflex were present . His right extremities were paralyzed and did not respond to pain Deep tendon reflexes were exaggerated on the right side and the plantar response was extensor on the right . No meningeal signs were present . Laboratory examination revealed the following abnormalities; WBC 18,400/ml, GOT 131 IU/l GPT 50 IU/l, CK616 IU/l, BUN 30 mg/dl, Cr 2.1 mg/ dl, glucose 339 mg/dl, and CRP 27.4 mg/dl . ECG showed sinus tachycardia and ST elevation in II, III and a VF leads and abnormal q waves in I, V5, and V6 leads . Chest X-ray revealed cardiac enlargement but the lung fields were clear . Cranial CT scan revealed low density areas in the left middle cerebral and left posterior cerebral artery territories . The patient was treated with intravenous glycerol infusion and other supportive measures . At 2: 10 AM on May 3, he developed sudden hypotension and cardiopulmonary arrest . He was pronounced dead at 3:45 AM . The patient was discussed in a neurological CPC, and the chief discussant arrived at the conclusion that the patient had acute myocardial infarction involving the inferior and the true posterior walls and left internal carotid embolism from a mural thrombus . Post mortem examination revealed occlusion of the circumflex branch of the left coronary artery due to atherom plaque rupture and myocardial infarction involving the posterior and the lateral wall with a rupture in the postero-lateral wall . Marked atheromatous changes were seen in the left internal carotid, the middle cerebral and the basilar arteries; the left internal carotid and the middle cerebral arteries were almost occluded by thrombi and blood coagulate . The territories of the left middle cerebral and the occipital arteries were infarcted; but the left thalamic area was spared . The neuropathologist concluded that the infarction was thrombotic origin not an embolic one as the atherosclerotic changes were severe . Cardiac rupture appeared to be the cause of terminal sudden hypotension and cardiopulmonary arrest . It appears likely that a vegetation which had been attached to the aortic valve induced thromboembolic occlusion of the left internal carotid artery which had already been markedly sclerotic by atherosclerosis . It is also possible that the vegetations in the aortic valve came from mural thrombi at the site of acute myocardial infarction, as no bacteria were found in those vegetations.

Genetics, 1997 Nov, 147(3), 961 - 77
Annealing vs . invasion in phage lambda recombination; Stahl MM et al.; Genetic recombination catalyzed by lambda's Red pathway was studied in rec+ and recA mutant bacteria by examining both intracellular lambda DNA and mature progeny particles . Recombination of nonreplicating phage chromosomes was induced by double-strand breaks delivered at unique sites in vivo . In rec+ cells, cutting only one chromosome gave nearly maximal stimulation of recombination; the recombinants formed contained relatively short hybrid regions, suggesting strand invasion . In contrast, in recA mutant cells, cutting the two parental chromosomes at non-allelic sites was required for maximal stimulation; the recombinants formed tended to be hybrid over the entire region between the two cuts, implying strand annealing . We conclude that, in the absence of RecA and the presence of non-allelic DNA ends, the Red pathway of lambda catalyzes recombination primarily by annealing.

Berl Munch Tierarztl Wochenschr, 1997 Dec, 110(11-12), 461 - 5
{PARS--a software program for pathologic anatomic diagnosis of wild animals}; Wisser J et al.; A computer programme (PARS) was designed for the collection of Pathological-Anatomical References of the Institute for Zoo Biology and Wildlife Research . We systemized more than 40,000 postmortem cases in order to develop a data bank for wild animal pathology . The PARS-programme was designed on the basis of PARADOX 7 for WINDOWS . As a netwoking programme with a central server it offers direct access to the data of the IZW case documentation for all scientists . In order to minimize desk work, the programme contains tables of zoological systemic (amphibians, reptiles, birds and mammals) as well as tables for systemic assignment (bacteria, viruses, fungi, protozoa, helminths and arthropods) for most common species . The records and findings of the necropsies can be printed immediately.

Berl Munch Tierarztl Wochenschr, 1997 Dec, 110(11-12), 431 - 5
{Veterinary medicine and preventive medicine}; Reuter G; Veterinary medicine concentrates its main activities onto the curative practice for animals but also onto the field of health protection for men since a very long time . But as late as in the year 1900 the first regulation by law within the modern world was edited in Germany . It was initiated by the well-known pathologist Virchow in Berlin and elaborated, besides other veterinarians, by the first food hygienist at the Veterinary School of Berlin, Robert von Ostertag . At that time, the protection of men from the classical infections caused by bacteria was the target, e.g . tuberculosis and the so-called food poisoning . Also, parasitoses like trichinellosis or hydatidosis were the most fought enemies . Nearly 100 years after the application of this regulation by law new types of zoonoses or zooanthroponoses get importance in the view of preventive medicine fulfilled by veterinarians . That are infections which can not be recognized visually and clinically in the new breeding and fattening ways for animals . Such latent infections are the main targets in the present goals and objectives of food hygiene . An undefined and unsolved problem seems to be the occurrence of the BSE of cattle in Great Britain . It may be regarded as a new and intermediate form of a latent and apparent disease of animals which may be dangerous by an unknown way also for men . Since the seventies of this century, the interest of veterinary medicine was focussed also onto residue levels within the products from food animals . These are caused by "substances with pharmacological efficacy", illegally handled by agronoms or veterinarians or by "poisons from the contaminated environment" provoked by industrial emission or manipulations by men . A classical task of food hygiene within the veterinary medicine is to protect the consumer from being taken advantage of through the sale of products containing substantial disregulatory structures of animal tissues.

Berl Munch Tierarztl Wochenschr, 1997 Dec, 110(11-12), 418 - 21
{Observations on resistance monitoring in animal health}; Altreuther P et al.; This article describes conventional procedures which are used for susceptibility testing of bacteria isolated from food producing animals against anti-infective substances . Interpretation of results obtained from the different test methods and the conditions necessary to conduct these tests in view of a meaningful resistance monitoring are discussed . Currently, published data about the resistance situation in veterinary medicine are either not representative or have been determined under suboptimal conditions . In view of the public and often non-scientifically based discussion about bacterial resistance it is absolutely necessary to generate a scientifically valid database.

Otolaryngol Head Neck Surg, 1998 Jan, 118(1), 6 - 8
Fatal meningitis and brain abscess resulting from foreign body-induced otomastoiditis; Goldman SA et al.; Herein we report what we believe to be the only published case of an intracranial complication of otomastoiditis resulting from foreign-body material . The presence of a foreign body must be ruled out in any chronically draining ear, and all foreign material must be removed . The key to minimizing the morbidity of complications of infectious ear disease is early recognition and treatment . Early symptoms of complication include vertigo, new onset of headache or otalgia, or worsening headache or otalgia . Fever, malodorous ear drainage, and the presence of granulation tissue are warming findings . A high index of suspicion of infectious complications must be maintained in evaluating all patients with ear disease.

J Chromatogr B Biomed Sci Appl, 1997 Nov 21, 702(1-2), 1 - 20
L-Carnitine moiety assay: an up-to-date reappraisal covering the commonest methods for various applications; Marzo A et al.; L-Carnitine and its esters are typical endogenous substances . Their homeostatic equilibria are effectively controlled by various mechanisms which include rate-limiting enteral absorption, a multicomponent endogenous pool which is regulated according to a mammillary metabolism, an asymmetric body distribution and a saturable tubular reabsorption process leading to renal thresholds . In formal pharmacokinetic and metabolic investigations, the whole L-carnitine pool should be investigated, owing to the rapid interchange process between the various components of the pool . Free L-carnitine, as well as its acyl esters, must therefore be considered from an analytical viewpoint . L-Carnitine, acetyl-L-carnitine and total L-carnitine (the latter as an expression of the whole pool) can easily be assayed by enzyme or radioenzyme methods . Propionyl-L-carnitine and other esters containing fatty acids with more than three carbon atoms can be assayed using various HPLC approaches . Tandem mass spectrometry is another excellent approach to the assay of carnitine and its short-chain, medium-chain and long-chain esters . As L-carnitine contains a chiral carbon atom, the enantioselectivity of the assays is also considered in this review . Metabolites produced by enteral bacteria, namely tri-, di- and mono-methylamine, gamma-butyrobetaine, along with other systemic metabolites, namely trimethylamine N-oxide and N-nitroso dimethylamine, are very important in quantitative and toxicokinetic terms and require specific assay methods . This review covers the commonest methods of assaying carnitine and its esters, their impurities and pre-systemic and systemic metabolites and gives analytical details and information on their applications in pharmaceutics, biochemistry, pharmacokinetics and toxicokinetics.

Curr Opin Rheumatol, 1998 Jan, 10(1), 79 - 85
Rheumatic manifestations of infectious diseases in children; Adebajo AO; Infectious diseases continue to elicit worldwide attention . Many of these diseases have rheumatic manifestations as an incidental or principal feature . Because this is particularly true in children, rheumatic manifestations of infectious diseases in this population continue to be an area of great importance to rheumatologists . A variety of bacteria, viruses, fungi, and parasitic organisms can give rise to infectious diseases with rheumatic manifestations . A high index of clinical suspicion is frequently necessary for an accurate diagnosis . Prompt diagnosis and early and appropriate therapeutic intervention are usually required for a successful, and frequently curative, outcome . Over the past year, studies have addressed the pathogenetic mechanisms and clinical spectrum of the rheumatic manifestations of infectious diseases in children . There has been particular emphasis on septic arthritis, osteomyelitis, sickle-cell disease, and hepatitis C viral infection . There remains the daunting and unfortunate possibility of large numbers of children developing HIV-associated arthritis.

Am J Gastroenterol, 1998 Jan, 93(1), 26 - 9
Semiquantitative evaluation for diagnosis of Helicobacter pylori infection in relation to histological changes; Tokunaga Y et al.; OBJECTIVES: Several methods are used to detect Helicobacter pylori (HP) infection . However, few reports have evaluated the accuracy of each method and compared the grade of HP infection with the severity of histological changes . HP infection was evaluated semiquantitatively in relation to the severity of gastritis, and the sensitivity, specificity, and accuracy of several methods to detect HP infection were compared . METHODS: Biopsy specimens, obtained from a total of 64 patients who underwent endoscopy for evaluation of gastroduodenal diseases, were studied using a rapid urease test, culture, and histological assessment . An immunohistochemical method was used as the gold standard and graded according to the number of individual bacteria seen, as follows: 0 = 0; 1+ = <10; 2+ = 10-29; 3+ = 30-99; 4+ = >100 . The severity of gastritis was evaluated histologically in each specimen and compared with the grade of HP infection . RESULTS: The rapid urease test had a sensitivity of 53%, specificity of 100%, and accuracy of 73% . The culture method had a sensitivity of 75%, specificity of 100%, and accuracy of 86% . Sensitivities of the rapid urease test and the culture method decreased in a positive correlation with the decrease in total number of HP bacteria counted . Using the rapid urease test, sensitivity was <30% when the grade of HP infection was < or =2+, whereas 100% sensitivity was obtained when the grade of HP infection was 4+ . On the other hand, sensitivity of the culture method remained between 80% and 90% when HP infection was > or =2+ . The severity of gastritis determined with Rauws scores increased in a positive correlation with the grade of HP infection as evaluated by immunohistochemical stain . CONCLUSIONS: The rapid urease test and culture of HP may result in false-negative tests for a mild infection, although they had high sensitivity and specificity for moderate to severe infection . Immunohistochemical stain provides a reliable semiquantitative diagnosis of HP infection and a positive correlation with histological changes . Clinicians should be aware of the characteristics of each method to detect HP infection and select the appropriate one(s) for their purposes.

Appl Microbiol Biotechnol, 1997 Oct, 48(4), 553 - 62
Complete degradation of tetrachloroethene in coupled anoxic and oxic chemostats; Gerritse J et al.; Anaerobic tetrachloroethene (C2Cl4)-dechlorinating bacteria were enriched in slurries from chloroethene-contaminated soil . With methanol as electron donor, C2Cl4 and trichloroethene (C2HCl3) were reductively dechlorinated to cis-1,2-dichloroethene (cis-C2H2Cl2), whereas, with L-lactate or formate, complete dechlorination of C2Cl4 via C2HCl3, cis-C2H2Cl2 and chloroethene (C2H3Cl) to ethene was obtained . In oxic soil slurries with methane as a substrate, complete co-metabolic degradation of cis-C2H2Cl2 was obtained, whereas C2HCl3 was partially degraded . With toluene or phenol both of the above were readily co-metabolized . Complete degradation of C2Cl4 was obtained in sequentially coupled anoxic and oxic chemostats, which were inoculated with the slurry enrichments . Apparent steady states were obtained at various dilution rates (0.02-0.4 h-1) and influent C2Cl4-concentrations (100-1000 microM) . In anoxic chemostats with a mixture of formate and glucose as the carbon and electron source, C2Cl4 was transformed at high rates (above 140 micromol 1-1 h-1, corresponding to 145 nmol Cl- min-1 mg protein-1), into cis-C2H2Cl2 and C2H3Cl . Reductive dechlorination was not affected by addition of 5 mM sulphate, but strongly inhibited after addition of 5 mM nitrate . Our results (high specific dechlorination rates and loss of dechlorination capacity in the absence of C2Cl4) suggest that C2Cl4-dechlorination in the anoxic chemostat was catalysed by specialized dechlorinating bacteria . The partially dechlorinated intermediates, cis-C2H2Cl2 and C2H3Cl, were further degraded by aerobic phenol-metaboizing bacteria . The maximum capacity for chloroethene (the sum of tri-, di- and monochloro derivatives removed) degradation in the oxic chemostat was 95 micromol 1-1 h-1 (20 nmol min-1 mg protein-1), and that of the combined anoxic --> oxic reactor system was 43.4 micromol 1-1 h-1 . This is significantly higher than reported thus far.

Mol Med Today, 1995 Nov, 1(8), 385 - 91
Role of endogenous enteric organisms in the reactivation of arthritis; Lichtman SN; Reactive arthritis is an acute form of arthritis apparently caused by a combination of bacterial infection and genetic influences . Recent experiments using an animal model suggest that certain bacterial cell wall polymers originating from endogenous enteric bacteria may be responsible for the condition.

Mol Microbiol, 1997 Oct, 26(1), 81 - 90
Dephosphorylation of the phosphoprotein P(II) in Synechococcus PCC 7942: identification of an ATP and 2-oxoglutarate-regulated phosphatase activity; Irmler A et al.; The phosphorylation state of the putative signal transduction protein P(II) from the cyanobacterium Synechococcus sp . strain PCC 7942 depends on the cellular state of nitrogen and carbon assimilation . In this study, dephosphorylation of phosphorylated P(II) protein (P{II}-P) was investigated both in vivo and in vitro . The in vivo studies implied that P(II)-P dephosphorylation is regulated by inhibitory metabolites involved in the glutamine synthetase-glutamate synthase pathway of ammonium assimilation . An in vitro assay for P(II)-P dephosphorylation was established that revealed a Mg2+-dependent P(II)-P phosphatase activity . P(II)-P phosphatase and P(II) kinase activities could be separated biochemically . A partially purified P(II)-P phosphatase preparation also catalysed the dephosphorylation of phosphoserine/phosphothreonine residues on other proteins in a Mg2+-dependent manner . However, only dephosphorylation of P(II)-P was regulated by synergistic inhibition by ATP and 2-oxoglutarate . As the same metabolites stimulate the P(II) kinase activity, it appears that the phosphorylation state of P(II) is determined by ATP and 2-oxoglutarate-dependent reciprocal reactivity of P(II) towards its phosphatase and kinase.

Am J Respir Crit Care Med, 1998 Jan, 157(1), 76 - 80
Diagnosis of nosocomial pneumonia in mechanically ventilated patients: repeatability of the bronchoalveolar lavage; Gerbeaux P et al.; The repeatability of the bronchoalveolar lavage (BAL) was assessed prospectively in 44 mechanically ventilated patients with suspected nosocomial pneumonia . Two BAL were performed in the same lung area (contiguous segment) during two fibroscopic procedures performed with a thirty minute interval . All the bronchoscopies were performed by the same operator . The statistical analysis looked out for bias (MacNemar test), agreement, and repeatability (kappa test) . In the 44 patients studied, the qualitative repeatability (i.e., presence or absence of bacteria) was excellent (95.4%) . However, in the 16 patients having at least one positive culture, these results were more controversial . The quantitative repeatability for bacteria (same log10 for both BAL of the same patient) was the lowest of all the results (26.7%) . The distinction between presence and absence of bacterial pneumonia (based on the 10{4} cfu/ml threshold) showed a repeatability of 75% with no bias, an agreement of 47% and a just-significant kappa test (test = 1.97; p = 1.96 for a 5% risk error) . BAL seems to have excellent repeatability when sterile . Its repeatability when positive needs further studies to be assessed.

Acta Otorhinolaryngol Belg, 1997, 51(4), 259 - 69
Diagnostic techniques in chronic sinusitis: endoscopy, sinusomanometry; Bertrand B et al.; The first endoscope was conceived as early as 1806 . Since then successive technical advances led endoscopy of the nose and paranasal sinuses to a routine procedure . From the rediscovery of the rigid telescopes by Hopkins in the fifties, progress has stemmed essentially from the quality of the more powerful cold lights and the improvement in the light output of the fiber optics . Exam procedures of the nose and sinuses are conducted under general as well as local anesthesia, and are commonly combined with concomitant diagnostic procedures: measure of the mucociliary clearance with indicators, biopsies, smear sampling for bacterial and fungal examinations, and sinusomanometry which can help to estimate the patency of the maxillary ostium and of the nasofrontal duct . Sinus endoscopy has been widely used to correlate efficiency of other diagnostic techniques such as plain X-rays, CT scanners, A and B mode ultrasonography . A similar work should be done for MRI . Endoscopic exploration is the key to the management of chronic pathology as it brings precise information on the quality of the naso-sinus mucosa, the presence of secretions and, combined with sinusomanometry, the functional state of the ostia or ducts.

Vet Microbiol, 1997 Oct 16, 57(4), 347 - 54
Classification of Arcobacter species isolated from aborted pig fetuses and sows with reproductive problems in Brazil; de Oliveira SJ et al.; Seventeen field isolates of Arcobacter species were recovered in Brazil from aborted porcine fetal livers (n = 3), kidneys (n = 2), and thoracic fluid (n = 1) . Arcobacter species were also recovered from uterine and oviductal tissues (n = 5) and a placenta from sows with reproductive problems . These isolates were initially presumed to be Arcobacter cryaerophilus on the basis of aerobic growth at 30 degree C, indoxyl acetate hydrolysis, catalase and oxidase reactions, growth on MacConkey agar, sensitivity to 3.5% sodium chloride, and susceptibility to nalidixic acid (40 mg/ml) . The isolates were confirmed as Arcobacter using polymerase chain reaction, and were classified as A . cryaerophilus 1A (24%), A . cryaerophilus 1B (71%), and A . butzleri (6%) using restriction fragment length polymorphism.

Pharmacol Rev, 1997 Dec, 49(4), 369 - 79
Pharmacogenetics in biological perspective; Kalow W; What have we learned? Pharmacogenetics, heritable variation in response to xenobiotics, is present in all forms of life . Initially, human data perhaps have created the most excitement, and they provide much biochemical detail . However, if we look at pharmacogenetic variation of insects and bacteria, we see it as a characteristic of populations; individuals with inborn resistance to various toxicants can cause the survival of a population by the process of Darwinian selection . Diversity of a population and Darwinian selection are different milestones serving population survival . Variation of drug response may represent variation of drug targets, drug metabolism, and probably drug transport . Metabolic variation appears to be the most prominent; at present, it is not clear whether this prominence has historical or biological causes . It is an interesting exercise to compare pharmacogenetic resistance with intoxication and resistance to infection by invasion of disease-carrying bacteria or other pathogens . The big difference is that pathogens tend to show variabilities that drugs do not have . The immune system is made to deal with the genetic variabilities linked to the short life span of most pathogens . However, there are, besides the immune system, several cases of genetic host resistance associated with the long life span of mammalian hosts . Such genetic host resistances are factors equivalent to pharmacogenetic variation . Current data pertain to resistance against malaria, tuberculosis, cholera, and AIDS . Most pharmacogenetic variants within a population are preadaptive, that is, they are established before xenobiotic exposure . Hence, one must postulate a multiplicity of variants in a population capable of resisting a multiplicity of drugs . The persistence of this multiplicity suggests that most variants are either present in heterozygous form and are thereby advantageous for their carriers, or they are selectively neutral mutants . It means that the biological cost of pharmacogenetic diversity, measured in terms of reduced fertility, should be low in a population . The frequencies of variant genes are usually not the same in different populations . Also the nucleotide substitutions in a variable gene often differ between populations . In other words, pharmacogenetic differences between populations are typical events . Pharmacogenetics is usually thought of as the study of a situation in which a single gene product exerts control over a given drug response so that a failure to respond, or an excessive response, may result . However, one should not forget that random variation is always present, probably reflecting the randomness of mutations plus variation of any environmental factors that might contribute . This underlying randomness of variation will always affect the picture of any all-or-none variation . Future pharmacogenetics must deal with both random and monogenic variation.

Antonie Van Leeuwenhoek, 1997 Nov, 72(4), 317 - 25
Exserohilum sodomii, a new species isolated from soil near the Dead Sea (Israel); Guiraud P et al.; Exserohilum sodomii sp . nov., is described . This new species was isolated from a soil sample from the Dead Sea surroundings . Its main physiological properties, as well as the influence of temperature and salts concentration in the culture medium on growth and morphology of the fungus were investigated and discussed.

J Biol Chem, 1998 Jan 23, 273(4), 2452 - 7
Role of the core DNA polymerase III subunits at the replication fork . Alpha is the only subunit required for processive replication; Marians KJ et al.; The DNA polymerase III holoenzyme is composed of 10 subunits . The core of the polymerase contains the catalytic polymerase subunit, alpha, the proofreading 3'-->5' exonuclease, epsilon, and a subunit of unknown function, theta . The availability of the holoenzyme subunits in purified form has allowed us to investigate their roles at the replication fork . We show here that of the three subunits in the core polymerase, only alpha is required to form processive replication forks that move at high rates and that exhibit coupled leading- and lagging-strand synthesis in vitro . Taken together with previous data this suggests that the primary determinant of replication fork processivity is the interaction between another holoenzyme subunit, tau, and the replication fork helicase, DnaB.

J Biol Chem, 1998 Jan 23, 273(4), 2329 - 35
Association of neurofilament proteins with neuronal Cdk5 activator; Qi Z et al.; Cdk5 exists in brain extracts in multiple forms, one of which is a macromolecular protein complex comprising Cdk5, neuron-specific Cdk5 activator p35nck5a and other protein components (Lee, K.-Y., Rosales, J . L., Tang, D., and Wang, J.H . (1996) J . Biol . Chem . 271, 1538-1543) . The yeast two-hybrid system was employed to identify p35nck5a-interacting proteins from a human brain cDNA library . One of the isolated clones encodes a fragment of glial fibrillary acidic protein, which is a glial-specific protein . Sequence alignment revealed significant homology between the p35nck5a-binding fragment of glial fibrillary acidic protein and corresponding regions in neurofilaments . The association between p35nck5a and neurofilament medium molecular weight subunit (NF-M) was confirmed by both the yeast two-hybrid assay and direct binding of the bacteria-expressed proteins . The p35nck5a binding site on NF-M was mapped to a carboxyl-terminal region of the rod domain, in close proximity to the putative Cdk5 phosphorylation sites in NF-M . A region immediately amino-terminal to the kinase-activating domain in p35nck5a is required for its binding with NF-M . In in vitro binding assays, NF-M binds both monomeric p35nck5a and the Cdk5/p35nck5a complex . The binding of NF-M has no effect on the kinase activity of Cdk5/p35nck5a.

J Biol Chem, 1998 Jan 16, 273(3), 1393 - 402
The copines, a novel class of C2 domain-containing, calcium-dependent, phospholipid-binding proteins conserved from Paramecium to humans; Creutz CE et al.; In an attempt to identify proteins that might underlie membrane trafficking processes in ciliates, calcium-dependent, phospholipid-binding proteins were isolated from extracts of Paramecium tetraurelia . The major protein obtained, named copine, had a mass of 55 kDa, bound phosphatidylserine but not phosphatidylcholine at micromolar levels of calcium but not magnesium, and promoted lipid vesicle aggregation . The sequence of a 920-base pair partial cDNA revealed that copine is a novel protein that contains a C2 domain likely to be responsible for its membrane active properties . Paramecium was found to have two closely related copine genes, CPN1 and CPN2 . Current sequence data bases indicate the presence of multiple copine homologs in green plants, nematodes, and humans . The full-length sequences reveal that copines consist of two C2 domains at the N terminus followed by a domain similar to the A domain that mediates interactions between integrins and extracellular ligands . A human homolog, copine I, was expressed in bacteria as a fusion protein with glutathione S-transferase . This recombinant protein exhibited calcium-dependent phospholipid binding properties similar to those of Paramecium copine . An antiserum raised against a fragment of human copine I was used to identify chromobindin 17, a secretory vesicle-binding protein, as a copine . This association with secretory vesicles, as well the general ability of copines to bind phospholipid bilayers in a calcium-dependent manner, suggests that these proteins may function in membrane trafficking.

Prikl Biokhim Mikrobiol, 1997 Sep-Oct, 33(5), 467 - 87
{Localization of catalysis enzyme systems that degrade higher plants' cell wall polysaccharides . Pectinases (review)}; Rodionova NA et al.; This paper reviews recent data on the locations and compositions of enzyme systems catalyzing the cleavage of cellulose, hemicelluloses, and pectin polysaccharides in higher plants . The physiological functions and physicochemical properties of certain enzymes degrading pectin polymers in higher plants, fungi, and bacteria are described.

Hautarzt, 1997 Oct, 48(10), 743 - 8
{Eccrine hidradenitis . Case report and review of the literature}; Okcu A et al.; Neutrophilic eccrine hidradenitis is a self-limited dermatosis with spontaneous resolution . The clinical presentation and location of the lesions are variable . Histopathologically, neutrophilic eccrine hidradenitis is characterized by a predominantly neutrophilic or mononuclear infiltrate around the eccrine ducts with associated necrosis . Possible causes include malignant hematological disorders, tumors, side effects of chemotherapy and bacteria infections . We report a 16-month-old female patient with idiopathic neutropenia undergoing G-CSF therapy, who suddenly developed numerous papules on her trunk and extremities . The lesions resolved spontaneously within 6 weeks without treatment . The clinical and histopathological findings of the hitherto published 45 cases are reviewed.

Respirology, 1996 Dec, 1(4), 221 - 5
Bronchiectasis: a neglected cause of respiratory morbidity and mortality; Kolbe J et al.; Bronchiectasis is a progressive condition characterized by irreversible destruction and dilation of airways generally associated with chronic bacterial infections . Although in Western countries, the morbidity and mortality from bronchiectasis is considered to have declined markedly in the modern era, the condition continues to cause significant morbidity and mortality in the south-west Pacific and probably also in South-East Asia . There is a high prevalence in indigenous populations in the region and factors such as poverty, substandard housing, malnutrition, barriers to medical care and inadequate education are all likely to have a major impact on prevalence and outcome of bronchiectasis . Although bronchiectasis has been viewed as a disease of medium and large airways, there is now increasing evidence of the importance of small airways disease in bronchiectasis and that it may play an integral role in pathogenesis . Chronic inflammation of the bronchial wall by mononuclear cells is common to all types of bronchiectasis . A vicious cycle of bacteria (mediated lung toxicity and bacteria) provoked, host-mediated inflammatory lung damage has been described . If progressive lung damage with its attendant morbidity and mortality is to be prevented, this vicious cycle needs to be broken . The two distinct therapeutic goals in bronchiectasis are to reduce morbidity and to prevent progression of underlying disease . It may be possible to modulate the host response directly and thus reduce tissue damage, but the precise role of immuno-modulatory therapy in bronchiectasis is still unclear . The management of this hitherto neglected disease, which reaches almost epidemic proportions in some ethnic groups and is an ongoing source of considerable morbidity and mortality, requires a comprehensive, multidisciplinary approach, which can be modelled on the successful management of chronic asthma in New Zealand.

J Thorac Imaging, 1998 Jan, 13(1), 52 - 7
Pulmonary high-resolution computed tomography versus gallium scintigraphy: diagnostic utility in the diagnosis of patients with AIDS who have chest symptoms and normal or equivocal chest radiographs; Kirshenbaum KJ et al.; Fifty-six consecutive symptomatic patients with AIDS referred for gallium scintigraphy were prospectively studied with chest high-resolution computed tomography (HRCT) . Results of gallium and HRCT were correlated with findings of bronchoscopy or clinical follow-up for 1 month from time of discharge . Twenty-two patients were eventually diagnosed with at least one of the following: Pneumocystis carinii, cytomegalovirus, Mycobacterium avium complex, bacteria, Kaposi's sarcoma, or lymphocytic interstitial pneumonitis . HRCT was more sensitive (82%) and more specific (91%) than gallium (59% and 75%, respectively) . HRCT yielded higher positive predictive values (86%) and negative predictive values (88%) than did gallium (62% and 73%, respectively) . HRCT was more helpful in guiding the method of biopsy and directing the brochoscopist to the diseased lung segment that would maximize diagnostic yield.

Aust N Z J Surg, 1998 Jan, 68(1), 65 - 7
Studies of the surgical scrub; Poon C et al.; BACKGROUND: To evaluate the effectiveness of various scrub techniques in reducing bacterial skin flora, the present study was developed in three stages . METHODS: Each stage involved fingertip bacterial colony counts measured before, immediately after and 30 min after a variety of handwashing techniques using 10% povidone iodine solution . The first compared 1, 2 or 3 non-timed washes from fingertips to elbows in 10 volunteers . The second compared two volunteers scrubbing for equal durations with or without friction rubbing, while the third involved 15 volunteers who each scrubbed for different time intervals . RESULTS: The first stage showed that a single wash episode failed to provide lasting bacterial colony count reductions on fingertip cultures . The second showed that enduring colony count reductions occur whether friction rubbing of the hands was used or not, and the third showed that a 30 s wash was as effective as washing for longer periods in reducing fingertip flora . CONCLUSIONS: These findings suggest that prolonged vigorous pre-operative scrubbing is unnecessary, although more than a cursory wash is required to produce lasting fingertip antisepsis.

Genetica, 1997, 100(1-3), 63 - 72
Do the integrases of LTR-retrotransposons and class II element transposases have a common ancestor?
Capy P, Langin T, Higuet D, Maurer P, Bazin C.
The integrases of retrotransposons (class I) and retroviruses and the transposases of bacterial type elements (class II) were compared . The DDE signature that is crucial for the integration of these elements is present in most of them, except for the non-LTR retrotransposons and members of the hAT and P super-families . Alignment of this region was used to infer the relationships between class II elements, retrotransposons, and retroviruses . The mariner-Tc1 and the Pogo-Fot1 super-families were found to be closely related and probably monophyletic, as were LTR retrotransposons and retroviruses . The IS elements of bacteria were clustered in several families, some of them being closely related to the transposase of the mariner-Tc1 super-family or to the LTR retrotransposon and retrovirus integrases . These results plus that of Xiong and Eickbush (1990) were used to develop an evolutionary history suggesting a common ancestral origin(s) for the integrases and transposases containing the DDE signature . The position of the telomeric elements (Het-A and TART) was assessed by comparing their gag and reverse transcriptase domains (when present) to those of group II introns and non-LTR retrotransposons . This preliminary analysis suggests that telomeric elements may be derived from non-LTR retrotransposons.

Mutat Res, 1997 Dec, 387(3), 123 - 39
Genotoxic activity of praziquantel; Montero R et al.; Praziquantel is a synthetic drug with a remarkable activity against parasites, particularly treamatodes and cestodes . Initial genotoxicity tests used a spectrum of endpoints including tests in bacteria, yeasts, mammalian cells and Drosophila and each one gave negative results . Effects on reproductive cells of mice were negative as well . However, host mediated studies in mice and humans were contradictory and a comutagenic effect with several mutagens and carcinogens was found . Later studies, including monitoring in humans and pigs have shown that Praziquantel induces a greater frequency of hyperploid lymphocytes as well as structural chromosomal aberrations, but not in all the individuals treated . In vitro studies have demonstrated that Praziquantel can induce micronuclei in syrian hamster embryonic (SHE) cells and in lymphocytes of some individuals . The same was found about structural chromosomal aberrations . Fetal death and fetal resorption were found when Praziquantel was administered in high doses to pregnant rats between the 6th and 10th day of gestation . Due to its efficiency as a parasiticide, Praziquantel is in use in Latin-American, Asiatic, African and East-European countries where infections by trematodes and cestodes are frequent . However, the extensive use of Praziquantel in multiple reinfections, in non-infected and non-diagnosed individuals for prevention, in higher doses or repeated doses for cysticercosis treatment and in individuals exposed to environmental mutagens, in conjunction with new findings about its metabolism and genotoxic properties, make it necessary to further evaluate the potential of this drug not only to be mutagenic per se, but to contribute in the development of neoplasm.

Biochem Biophys Res Commun, 1998 Jan 6, 242(1), 213 - 8
Characterization of the cytochromes C from Desulfovibrio desulfuricans G201; Aubert C et al.; A monoheme cytochrome c553 and a hexadecaheme high molecular weight cytochrome (Hmc) have been isolated and characterized from the sulfate-reducing bacteria Desulfovibrio desulfuricans G201, in addition to the tetraheme cytochrome c3 (Mr 13000) that has been previously described . Both cytochromes are homologous with respect to several biochemical properties to the corresponding cytochromes found in other Desulfovibrio species . However, they are acidic proteins while the corresponding molecules, isolated from other Desulfovibrio species, are relatively more basic . The D . desulfuricans cytochrome content appears identical to that of D . vulgaris Hildenborough . Isolation of these cytochromes from a Desulfovibrio desulfuricans strain is of great interest in order to get more insight on the physiological function of these molecules.

Biochem J, 1997 Dec 1, 328 ( Pt 2), 581 - 6
A novel type of thermostable alpha-D-glucosidase from Thermoanaerobacter thermohydrosulfuricus exhibiting maltodextrinohydrolase activity; Wimmer B et al.; An alpha-glucosidase with the ability to attack polymeric substrates was purified to homogeneity from culture supernatants of Thermoanaerobacter thermohydrosulfuricus DSM 567 . The enzyme is apparently a glycoprotein with a molecular mass of 160 kDa . Maximal activity is observed between pH5 and 7 at 75 degrees C . The alpha-glucosidase is active towards p-nitrophenyl-alpha-D-glucoside, maltose, malto-oligosaccharides, starch and pullulan . Highest activity is displayed towards the disaccharide maltose . In addition to glucose, maltohexaose and maltoheptaose can be detected as the initial products of starch hydrolysis . After short incubations of pullulan, glucose is found as the only product . At high substrate concentrations, maltose and malto-oligosaccharide, but not glucose, are used as acceptors for glucosyl-transfer . These findings indicate that the T . thermohydrosulfuricus enzyme represents a novel type of alpha-glucosidase exhibiting maltase, glucohydrolase and 'maltodextrinohydrolase' activity.

Nucleic Acids Res, 1997 Dec 1, 25(23), 4764 - 70
Identification and developmental characterization of a novel Y-box protein from Drosophila melanogaster; Thieringer HA et al.; The Y-box proteins are a family of highly conserved nucleic acid binding proteins which are conserved from bacteria to human . In this report we have identified a new member of this family from Drosophila melanogaster . Degenerate-PCR was used to identify a conserved region within the highly conserved cold-shock domain (CSD) of Y-box proteins . Subsequently, the cDNA for this gene was sequenced, and the identified open reading frame was named ypsilon schachtel (yps) . The expression pattern of yps indicates that this gene is expressed throughout development with the highest level of expression found in adult flies . In situ hybridization shows that the yps mRNA is maternally loaded into the egg cytoplasm . In addition, there appears to be expression of yps mRNA in mesodermal tissue during embryogenesis . YPS, while containing a conserved CSD, is novel in that it completely lacks the alternating acidic and basic regions found in the C-terminus of the other vertebrate eukaryotic Y-box proteins . The CSD of yps was purified and gel-shift analysis showed that this domain can interact with RNA . We predict that YPS would be an RNA-binding protein due to these results and the motifs which have been identified within the amino acid sequence.

Caries Res, 1998, 32(1), 70 - 4
A mathematical model of the influence of salivary urea on the pH of fasted dental plaque and on the changes occurring during a cariogenic challenge; Dibdin GH et al.; Urea diffusing from saliva into dental plaque is converted to ammonia and carbon dioxide by bacterial ureases . The influence of normal salivary urea levels on the pH of fasted plaque and on the depth and duration of a Stephan curve is uncertain . A numerical model which simulates a cariogenic challenge (a 10% sucrose rinse alone or one followed by use of chewing-gum with or without sugar) was modified to include salivary urea levels from 0 to 30 mmol/l . It incorporated: site-dependent exchange between bulk saliva and plaque surfaces via a salivary film; sugar and urea diffusion into plaque; pH-dependent rates of acid formation and urea breakdown; diffusion and dissociation of end-products and other buffers (acetate, lactate, phosphate, ammonia and carbonate); diffusion of protons and other ions; equilibration with fixed and mobile buffers; and charge-coupling between ionic flows . The Km (2.12 mmol/l) and Vmax (0.11 micromol urea/min/mg dry weight) values for urease activity and the pH dependence of Vmax were taken from the literature . From the results, it is predicted that urea concentrations normally present in saliva (3-5 mmol/l) will increase the pH at the base of a 0.5-mm-thick fasted plaque by up to 1 pH unit, and raise the pH minimum after a sucrose rinse or sugar-containing chewing-gum by at least half a pH unit . The results suggest that plaque cariogenicity may be inversely related to salivary urea concentrations, not only when the latter are elevated because of disease, but even when they are in the normal range.

J Matern Fetal Med, 1997 Nov-Dec, 6(6), 320 - 3
Feasibility of an obstetrician-based cord blood collection network for unrelated donor umbilical cord blood banking; Wall DA et al.; The purpose of this study was to evaluate the feasibility of an obstetrician-based cord blood collection system for the purpose of banking cord blood for unrelated donor hematopoietic stem cell transplantation . Over 200 delivering physicians and 40 area obstetrical units were educated and became involved in the collection of cord blood during the third stage of labor . These products compared favorable with those obtained after placental delivery . Issues involved in the development of quality assurance for unrelated donor banking are discussed . An obstetrician-based cord blood collection network is feasible and advantageous in that cord blood can be collected from a wider variety of communities, thus enhancing the ethnic diversity of a bank.

J Exp Zool, 1998 Jan 1, 280(1), 73 - 85
Molecular evolution of Hox gene regulation: cloning and transgenic analysis of the lamprey HoxQ8 gene; Carr JL et al.; The mammalian Hox clusters arose by duplication of a primordial cluster . The duplication of Hox clusters created redundancy within cognate groups, allowing for change in function over time . The lamprey, Petromyzon marinus, occupies an intermediate position within the chordates, both in terms of morphologic complexity and possibly cluster number . To determine the extent of divergence among Hox genes after duplication events within vertebrates, we analyzed Hox genes belonging to cognate group 8 . Here we report characterization of the HoxQ8 gene, which shows conservation with mammalian genes in its amino-terminal, homeobox and hexapeptide sequences, and in the position of its splice sites . A beta-galactosidase reporter gene was introduced in the HoxQ8 genomic region by targeted recombinational cloning using a yeast-bacteria shuttle vector, pClasper . These reporter gene constructs were tested for their ability to direct region-specific expression patterns in transgenic mouse embryos . Lamprey enhancers direct expression to posterior neural tube but not to mesoderm, suggesting conservation of neuronal enhancers . In the presence of the mouse heat shock promoter, lamprey enhancers could also direct expression to the posterior mesoderm suggesting that there has been some divergence in promoter function . Our results suggest that comparative studies on Hox gene structure and analysis of regulatory elements may provide insights into changes concomitant with Hox cluster duplications in the chordates.

RNA, 1998 Jan, 4(1), 38 - 46
Effect of frameshift-inducing mutants of elongation factor 1alpha on programmed +1 frameshifting in yeast; Farabaugh PJ et al.; The translational apparatus very efficiently eliminates errors that would cause a spontaneous shift in frames . The probability of frameshifting can be increased dramatically by either cis or trans-acting factors . Programmed translational frameshift sites are cis-acting sequences that greatly increase the frequency of such errors, at least in part by causing a transient translational pause . Pausing during programmed +1 frameshifts occurs because of slow recognition of the codon following the last read in the normal frame . Frameshifting can also be elevated in strains carrying mutations in the homologous elongation factors EF-Tu in bacteria, and EF-1alpha in the yeast Saccharomyces cerevisiae . This phenotype implies that the factors contribute to frame maintenance . Because EF-Tu/EF-1alpha modulate the kinetics of decoding, it is possible that the frameshift suppressor forms of the factors transiently slow normal decoding, allowing spontaneous frameshifting to occur more efficiently, resulting in phenotypic suppression . We have used a set of frameshift reporter plasmids to test the effect of suppressor forms of EF-1alpha on constructs that differ widely in the efficiency with which they stimulate +1 shifting . When these results were compared to the effect of increased translational pausing, it was apparent that the mutations affecting EF-1alpha do not simply prolong the translational pause . Rather, they appear to generally increase the likelihood of frame errors, apparently by affecting the error correction mechanism of the ribosome.

J Dairy Sci, 1997 Dec, 80(12), 3212 - 8
Recombinant bovine somatotropin and clinical mastitis: incidence, discarded milk following therapy, and culling; Judge LJ et al.; Holstein cows (n = 555) from four Michigan dairy farms were randomly assigned to receive bovine somatotropin (bST) or to serve as untreated controls . Bovine somatotropin (500 mg) was administered every 14 d beginning at 63 to 69 d of lactation and continuing until approximately 21 d prior to dry-off or until the cow was removed from the herd . Trial objectives were to determine the effect of bST on the incidence of clinical mastitis, number of days that milk was discarded because of therapy for clinical mastitis, and culling for mastitis . A total of 127 (22.9%) cases of clinical mastitis occurred during lactation . In the pretrial period (before 63 to 69 d of lactation), 42 (33.1%) cases occurred, and 85 (66.9%) cases occurred during the trial . Of the 42 pretrial cases, 57.1% occurred in control cows, and 42.9% occurred in treated cows . Of the 85 trial cases 47.1% occurred in control cows, and 52.9% occurred in treated cows . Using logistic regression, the odds ratio for the occurrence of clinical mastitis in treated cows was 1.06 (95% confidence interval = 0.62 to 1.81) . The number of days that milk was discarded following therapy for clinical mastitis and the culling rate for mastitis did not differ between study groups.

Medicina (B Aires), 1997, 57(1), 7 - 14
{Isolation of Chlamydia trachomatis and immune response in different populations}; Zapata MT et al.; We studied the presence of C . trachomatis-specific IgG and IgM in adults and newborns, respectively, and attempted isolation of the bacteria in cell culture . The determination of antibodies was carried out by an IFA on C . trachomatis infected (L2 434/Bu serotype) McCoy cells, cultured in 24-well plastic plates . We found C . trachomatis-specific IgG in 27% of women with clinical symptoms, in 40% of women being attended for periodic gynecological control, in 60% of infertile women and in 10% of pregnant women . A proportion comparison test revealed the presence of specific IgG as highly significative for the group of infertile women as compared to the group of pregnant women (p < 0.0001) . We divided the patients into four groups, in relation to the results of the tests for specific IgG and C . trachomatis isolation . Seven out of 10 had positive isolation and negative IFA, 5 out of 8 had positive isolation and negative IFA . Twenty five out of 28 pregnant women had negative isolation and positive IFA, finally, 63 out of 76 had both tests negative . Statistical analysis using the McNemar proportion-comparison test suggests that IgG's presence is highly significant in pregnant women with respect to other groups (p < 0.001) . Our results suggest that the demonstration of IgG is not enough for diagnostic purposes, except in infertile women with a previous history of infection with C . trachomatis . We isolated C . trachomatis in 20% of the newborns tested and 10% were also positive for IgM IFA . The diagnosis was improved by combining both techniques . These results show the importance of the detection of C . trachomatis in youngsters to avoid infertility and in pregnant women to prevent newborn infections and the possibility of premature births and low weight babies.

Proc Natl Acad Sci U S A, 1998 Jan 20, 95(2), 588 - 93
A family of human receptors structurally related to Drosophila Toll; Rock FL et al.; The discovery of sequence homology between the cytoplasmic domains of Drosophila Toll and human interleukin 1 receptors has sown the conviction that both molecules trigger related signaling pathways tied to the nuclear translocation of Rel-type transcription factors . This conserved signaling scheme governs an evolutionarily ancient immune response in both insects and vertebrates . We report the molecular cloning of a class of putative human receptors with a protein architecture that is similar to Drosophila Toll in both intra- and extracellular segments . Five human Toll-like receptors--named TLRs 1-5--are probably the direct homologs of the fly molecule and, as such, could constitute an important and unrecognized component of innate immunity in humans . Intriguingly, the evolutionary retention of TLRs in vertebrates may indicate another role--akin to Toll in the dorsoventralization of the Drosophila embryo--as regulators of early morphogenetic patterning . Multiple tissue mRNA blots indicate markedly different patterns of expression for the human TLRs . By using fluorescence in situ hybridization and sequence-tagged site database analyses, we also show that the cognate Tlr genes reside on chromosomes 4 (TLRs 1, 2, and 3), 9 (TLR4), and 1 (TLR5) . Structure prediction of the aligned Toll-homology domains from varied insect and human TLRs, vertebrate interleukin 1 receptors and MyD88 factors, and plant disease-resistance proteins recognizes a parallel beta/alpha fold with an acidic active site; a similar structure notably recurs in a class of response regulators broadly involved in transducing sensory information in bacteria.

Proc Natl Acad Sci U S A, 1998 Jan 20, 95(2), 520 - 4
Thermostabilization and thermoactivation of thermolabile enzymes by trehalose and its application for the synthesis of full length cDNA; Carninci P et al.; The advent of thermostable enzymes has led to great advances in molecular biology, such as the development of PCR and ligase chain reaction . However, isolation of naturally thermostable enzymes has been restricted to those existing in thermophylic bacteria . Here, we show that the disaccharide trehalose enables enzymes to maintain their normal activity (thermostabilization) or even to increase activity at high temperatures (thermoactivation) at which they are normally inactive . We also demonstrate how enzyme thermoactivation can improve the reverse transcriptase, reaction . In fact, thermoactivated reverse transcriptase, which displays full activity even at 60 degrees C, was powerful enough to synthesize full length cDNA without the early termination usually induced by stable secondary structures of mRNA.

J Eukaryot Microbiol, 1997 Nov-Dec, 44(6), 620 - 5
A new collection of thermosensitive endocytosis mutants in the cellular slime mold Dictyostelium discoideum; Labrousse A et al.; We used a photoactivatable fluid-phase marker to isolate a new collection of thermosensitive endocytosis mutants in the cellular slime mold Dictyostelium discoideum . All the strains were thermosensitive for growth on bacteria or axenic medium at 27 degrees C . Initial rates of endocytosis rapidly decreased upon incubation at the restrictive temperature, but surprisingly most of the strains showed a transient recovery of activity with prolonged exposure to 27 degrees C . Endocytosis and exocytosis activities were uncoupled for some of the cell lines at 27 degrees C whereas the others had to be shifted to 29 degrees C . Further molecular analysis of these mutants could lead to the discovery of new proteins involved in endocytosis and its regulation.

Appl Environ Microbiol, 1998 Jan, 64(1), 294 - 303
Phylogenetic diversity of ultraplankton plastid small-subunit rRNA genes recovered in environmental nucleic acid samples from the Pacific and Atlantic coasts of the United States; Rappe MS et al.; The scope of marine phytoplankton diversity is uncertain in many respects because, like bacteria, these organisms sometimes lack defining morphological characteristics and can be a challenge to grow in culture . Here, we report the recovery of phylogenetically diverse plastid small-subunit (SSU) rRNA gene (rDNA) clones from natural plankton populations collected in the Pacific Ocean off the mouth of Yaquina Bay, Oreg . (OCS clones), and from the eastern continental shelf of the United States off Cape Hatteras, N.C . (OM clones) . SSU rRNA gene clone libraries were prepared by amplifying rDNAs from nucleic acids isolated from plankton samples and cloning them into plasmid vectors . The PCR primers used for amplification reactions were designed to be specific for bacterial SSU rRNA genes; however, plastid genes have a common phylogenetic origin with bacteria and were common in both SSU rRNA gene clone libraries . A combination of restriction fragment length polymorphism analyses, nucleic acid sequencing, and taxon-specific oligonucleotide probe hybridizations revealed that 54 of the 116 OCS gene clones were of plastid origin . Collectively, clones from the OCS and OM libraries formed at least eight unique lineages within the plastid radiation, including gene lineages related to the classes Bacillariophyceae, Cryptophyceae, Prymnesiophyceae, Chrysophyceae, and Prasinophyceae; for a number of unique clones, no close phylogenetic neighbors could be identified with confidence . Only a group of two OCS rRNA gene clones showed close identity to the plastid SSU rRNA gene sequence of a cultured organism {Emiliania huxleyi (Lohmann) Hay and Mohler; 99.8% similar} . The remaining clones could not be identified to the genus or species level . Although cryptic species are not as prevalent among phytoplankton as they are among their bacterial counterparts, this genetic survey nonetheless uncovered significant new information about phytoplankton diversity.

Appl Environ Microbiol, 1998 Jan, 64(1), 279 - 86
Production of respirable vesicles containing live Legionella pneumophila cells by two Acanthamoeba spp; Berk SG et al.; Two Acanthamoeba species, fed at three temperatures, expelled vesicles containing living Legionella pneumophila cells . Vesicles ranged from 2.1 to 6.4 microns in diameter and theoretically could contain several hundred bacteria . Viable L . pneumophila cells were observed within vesicles which had been exposed to two cooling tower biocides for 24 h . Clusters of bacteria in vesicles were not dispersed by freeze-thawing and sonication . Such vesicles may be agents for the transmission of legionellosis associated with cooling towers, and the risk may be underestimated by plate count methods.

Mutat Res, 1997 Dec 12, 396(1-2), 163 - 73
Molecular/cellular biology of the heat stress response and its role in agent-induced teratogenesis; Mirkes PE; Available data indicate that heat shock proteins act as chaperones under non-stress conditions by assisting in: (1) the folding of newly synthesized proteins, (2) the intracellular translocation of proteins, and (3) the function of other proteins . As we gain additional information concerning cellular physiology, we may find that heat shock proteins play a key role in many additional cellular functions . When cells experience thermal or chemical stress, heat shock proteins take on a new role, conserved from bacteria to humans, of protecting cells from the detrimental effects of stress . This latter role takes on added significance for the embryo in which the developmental program must be read linearly, with little opportunity to cycle backward to complete a missed segment of the program . Although circumstantial evidence clearly implicates heat shock proteins in protecting embryos from thermal stress, definitive evidence is still lacking . The challenge for the future is to obtain such definitive data . Ideally, such information will lead to new therapeutic paradigms that will afford protection to the human embryo/fetus exposed to thermal/chemical stress.

J Am Acad Audiol, 1997 Dec, 8(6), 391 - 400
Physiology, pathophysiology, and anthropology/epidemiology of human earcanal secretions; Roeser RJ et al.; Two types of glands are found in the outer third of the human earcanal: sebaceous glands that produce sebum and modified apocrine glands that produce apocrine sweat . Together, these substances make up cerumen, which serves to clean, lubricate, and, to some extent, protect the earcanal from bacteria and fungus . Excessive/impacted cerumen can cause tinnitus, vertigo, itching, pain, external otitis, and hearing loss . Two populations are known to have a high incidence of excessive/impacted cerumen: individuals with mental retardation and the elderly . Anthropologists have used cerumen type to tract human migratory patterns and epidemiologists have related cerumen type to breast cancer.

Inflammation, 1997 Dec, 21(6), 597 - 608
In vivo dexamethasone effects on neutrophil effector functions in a rat model of acute lung injury; O'Leary EC et al.; Glucocorticoids, while potent antiinflammatory agents, have not been proven to be efficacious in Acute Respiratory Distress Syndrome, ARDS . Previous studies from this laboratory have reported that dexamethasone pretreatment of rats resulted in a 40-60% reduction in neutrophil influx into the airways following intratracheal administration of lipopolysaccharide, LPS . In the present study, the in vivo effects of dexamethasone on BAL neutrophil effector functions were evaluated by flow cytometry . BAL neutrophils from rats pretreated with dexamethasone (20 mg/kg, i.p . at 2 h before and 8 h after LPS) and harvested 20 h after LPS challenge demonstrated a 35% reduction in their ability to undergo an ex vivo oxidative burst with phorbol myristate acetate . This modest reduction in the oxidative burst was not related to a more general suppression of neutrophil effector functions as neither phagocytosis of opsonized bacteria nor expression of the beta-2 integrins CD11a and CD11b were similarly inhibited . Therefore, the neutrophil population which has migrated into the airways in dexamethasone pretreated rats retains the capacity to mediate host defense but also to exacerbate inflammation associated tissue damage.

Nature, 1998 Jan 8, 391(6663), 199 - 203
Structure of the alpha beta tubulin dimer by electron crystallography; Nogales E et al.; The alphabeta tubulin heterodimer is the structural subunit of microtubules, which are cytoskeletal elements that are essential for intracellular transport and cell division in all eukaryotes . Each tubulin monomer binds a guanine nucleotide, which is nonexchangeable when it is bound in the alpha subunit, or N site, and exchangeable when bound in the beta subunit, or E site . The alpha- and beta-tubulins share 40% amino-acid sequence identity, both exist in several isotype forms, and both undergo a variety of posttranslational modifications . Limited sequence homology has been found with the proteins FtsZ and Misato, which are involved in cell division in bacteria and Drosophila, respectively . Here we present an atomic model of the alphabeta tubulin dimer fitted to a 3.7-A density map obtained by electron crystallography of zinc-induced tubulin sheets . The structures of alpha- and beta-tubulin are basically identical: each monomer is formed by a core of two beta-sheets surrounded by alpha-helices . The monomer structure is very compact, but can be divided into three functional domains: the amino-terminal domain containing the nucleotide-binding region, an intermediate domain containing the Taxol-binding site, and the carboxy-terminal domain, which probably constitutes the binding surface for motor proteins.

Biochim Biophys Acta, 1997 Nov 14, 1343(1), 85 - 94
Proteolysis of Alzheimer's disease beta-amyloid precursor protein by factor Xa; Haas C et al.; Amyloid beta-protein is a 4-kDa peptide which originates from proteolysis of a larger protein precursor (APP) and accumulates in senile plaques in brains of Alzheimer's disease (AD) patients . Since secreted APP inhibits factors IXa, Xa and XIa, and thrombin appears to play a role in APP secretion and proteolysis, a relationship between hemostasis system and APP metabolism seems to exist . In this work we investigate the susceptibility to proteolytic cleavage by factor Xa of a fusion construct containing full-length APP prepared in bacteria, and demonstrate that both APP695 and APP770 are substrates for this protease . Factor Xa was found to cleave APP after arginines 102, 268, 510, 573 and 601 (APP695 numeration); most of these sites appear to be common for different coagulation factors . In addition, APP incubation with factor Xa generates an array of six potentially amyloidogenic fragments . Comparative kinetic analysis of APP695 and APP770 cleavage by factor Xa suggests that Kunitz-type inhibitor-containing isoforms exert an inhibitory effect on the protease . However, this inhibition is far from complete even at a 5-fold molar excess of inhibitor . Our results raise the possibility that proteases from the coagulation cascade may contribute to APP proteolysis, and support the notion that these proteases play a role in AD pathogenesis.

Gastroenterology, 1998 Jan, 114(1), 58 - 70
The role of internal urease in acid resistance of Helicobacter pylori; Scott DR et al.; BACKGROUND & AIMS: The relative role of internal urease for acid protection of Helicobacter pylori is unknown . The aim of this study was to determine the comparative importance of internal and external urease under acidic conditions . METHODS: The pH optimum and measured Michaelis constant for urea of external urease and urease in intact bacteria at different medium pH (pHout) were measured using 14CO2 release from 14C-urea . The effect of urea on membrane potential and bacterial cytoplasmic pH was measured at different fixed pHout . 35S-methionine labeling and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of labeled proteins in the organism and medium measured protein synthesis at different pHout and mechanisms of urease externalization . RESULTS: External urease had activity between pH 5.0 and 8.5 and internal urease between pHout 2.5 and 6.5, and its Michaelis constant at pHout 7.5 was 300 mmol/L but at pHout 4.5 was 0.5 mmol/L, similar to free urease . The addition of 5 mmol/L urea to bacteria at fixed pHout from 3.0 to 6.0 elevated potential to about -105 mV and periplasmic pH to about pH 6.2 . Protein synthesis occurred mainly between pH 6.5 and 8.0, and urease activity resulted in increased protein synthesis at acidic pH . The labeling pattern of intrabacterial and released protein was similar . CONCLUSIONS: Intracellular urease activity is regulated by external pH, defends against gastric acidity by increasing periplasmic pH and membrane potential, and stimulates protein synthesis at acidic pH . External urease is produced mostly by cell lysis.

Gastroenterology, 1998 Jan, 114(1), 15 - 22
Balsalazide is more effective and better tolerated than mesalamine in the treatment of acute ulcerative colitis . The Abacus Investigator Group; Green JR et al.; BACKGROUND & AIMS: Aminosalicylates are widely used in the treatment of ulcerative colitis (UC) . Balsalazide is a novel mesalamine prodrug, activated by colonic bacteria . The aim of this study was to compare the efficacy and safety of balsalazide with that of a pH-dependent formulation of mesalamine in active UC . METHODS: A randomized, double-blind study was performed comparing balasalazide, 6.75 g daily, with mesalamine, 2.4 g daily, administered for 4, 8, or 12 weeks to 101 (99 evaluable) patients with symptomatic, sigmoidoscopically verified UC . RESULTS: More patients treated with balsalazide achieved symptomatic remission after 2 (64% {balsalazide} vs . 43% {mesalamine}), 4 (70% vs . 51%), 8 (78% vs . 45%), and 12 weeks (88% vs . 57%) and complete remission (none/mild symptoms, sigmoidoscopy grade 0/1, no rectal steroid use within 4 days) after 4 (38% vs . 12%), 8 (54% vs . 22%), and 12 weeks (62% vs . 37%) . Patients taking balsalazide experienced more asymptomatic days (4 weeks, 24% vs . 14%) and achieved the first asymptomatic day more rapidly (median, 10 vs . 25 days) . Fewer patients in the balsalazide group reported adverse events (48% vs . 71%); four serious adverse events occurred in the mesalamine group . CONCLUSIONS: Balsalazide is more effective and better tolerated than mesalamine as treatment for acute UC.

Gene, 1997 Nov 20, 202(1-2), 53 - 9
Isolation and characterization of the UDP-glucose 4'-epimerase-encoding gene, galE, from Brucella abortus 2308; Scupham AJ et al.; The UDP-glucose 4'-epimerase-encoding gene, galE or exoB, was isolated from Brucella abortus 2308 by complementation of an exoB mutant of Sinorhizobium meliloti . Confirmation of the identity was done by constructing an in-frame deletion of 660 bp with galE of the B . abortus genome by marker exchange . The resulting galE mutant lacked UDP-glucose 4'-epimerase activity . This activity was restored by in trans complementation with the intact gene . The B . abortus gal E mutant is not altered in colony morphology compared to wt 2308 . The lack of UDP-glucose 4'-epimerase activity in the mutant and PCR analysis strongly suggest that only one copy of galE exists in B . abortus 2308 . The galE sequence of B . abortus 2308 is more similar to galE from other animal-inhabiting bacteria than it is to exoB from the Sinorhizobium legume symbionts . We propose that galE in B . abortus evolved by lateral transfer from other animal-inhabiting bacteria rather than from a common ancestor of Brucella and Sinorhizobium.

Mol Microbiol, 1997 Nov, 26(4), 699 - 708
Oscillin, an extracellular, Ca2+-binding glycoprotein essential for the gliding motility of cyanobacteria; Hoiczyk E et al.; Electron microscopic studies have demonstrated that various gliding filamentous cyanobacteria have trichome surfaces with a common structural organization . They contain an S-layer attached to the outer membrane and an array of parallel fibrils on top of the S-layer . In all species studied, the helical arrangement of these fibrils corresponds to the sense of rotation of the organism during the gliding movement . We have investigated the surface fibrils of Phormidium uncinatum using electron microscopic, spectroscopic and biochemical techniques . The fibrils consist of a single rod-shaped protein, which we refer to as oscillin . Oscillin is a 646 amino acid residue protein (Mr 65807; pI 3.63) and appears to be glycosylated . Sequence analysis reveals a two-domain structure: a 554 residue domain contains 46 repeats of a Ca2+-binding motif; it is followed by a 92 residue C-terminal domain, which might mediate its export . Filaments that do not express oscillin lose their ability to move . Homology studies suggest that similar proteins play comparable roles in other motile cyanobacteria . The structure of oscillin appears to favour a passive role in gliding.

FEBS Lett, 1997 Dec 8, 419(1), 83 - 6
Eicosanoids mediate induction of immune genes in the fat body of the silkworm, Bombyx mori; Morishima I et al.; The expression of cecropin and lysozyme genes is induced in response to bacterial peptidoglycan in the fat body of the silkworm, Bombyx mori . Specific inhibitors of either phospholipase A2, cyclooxygenase or lipoxygenase significantly inhibit the induction of the immune genes both in vivo and in cultured fat body as detected by means of Northern hybridization . Arachidonic acid injected into the larvae induces the expression of the cecropin and lysozyme genes . The findings support the idea that eicosanoids mediate some process leading to the expression of immune genes in the fat body following recognition of peptidoglycan as a signal for invading bacteria.

Biol Chem, 1997 Nov, 378(11), 1287 - 92
The consequence of translesional replication of unique UV-induced photoproducts; Gentil A et al.; The consequence of translesional replication of unique UV-induced photoproducts is reviewed here . Mutagenesis induced by unique UV-induced lesions, the thymine-thymine dimer (TT) and the thymine-thymine pyrimidine pyrimidone (6-4), {T(6-4)T} carried on single-stranded DNA vectors and replicated in bacteria, yeast and mammalian cells have been considered . It has been found that in all of the three species the (TT) dimers induce a low mutation frequency compared to the (6-4) photoproduct . The molecular analysis of the mutations induced is reported, showing specific differences depending on the species considered.

Mol Microbiol, 1997 Dec, 26(5), 1083 - 96
Evidence for two chemosensory pathways in Rhodobacter sphaeroides; Hamblin PA et al.; In contrast to enteric bacteria, chemotaxis in Rhodobacter sphaeroides requires transport and partial metabolism of chemoattractants . Although a chemotaxis operon has been identified containing homologues of the enteric cheA, cheW, cheR genes and two homologues of the cheY gene, deletion of the entire chemotaxis operon had only minor effects on chemotactic behaviour under the conditions tested . Responses to sugars were enhanced in tethered cells but in all other chemotaxis assays behaviour of the operon deletion mutant was wild type . The mutant also showed wild-type responses to weak organic acids such as acetate and propionate, the dominant chemoattractants for this organism, under all conditions . This is in direct contrast to the enterics in which CheA, CheW and CheY are absolutely essential for taxis to PTS sugars, oxygen and MCP-dependent chemoeffectors . The operon deletion mutant was subjected to Tn5 transposon mutagenesis and new mutants selected using a chemotaxis and phototaxis screen . One mutant, JPA203, was non-chemotactic on swarm plates and showed inverted responses when tethered or subjected to changes in light intensity . Characterization of the Tn5 insertion in JPA203 identified a second chemotaxis operon in R . sphaeroides that contains homologues of cheY, cheA and cheR, the first homologue of cheB and two homologues of cheW . The new genes were labelled orf10, cheY(III), cheA(II) cheW(II), cheW(III), cheR(II), cheB and tlpC . When introduced into a wild-type background, deletion of cheA(II) produced a chemotaxis minus phenotype in R . sphaeroides, suggesting that cheA(II) forms part of a dominant chemotactic pathway, whereas the earlier identified operon plays only a minor role under laboratory conditions . The data presented here support the existence of two chemosensory pathways in R . sphaeroides, a feature that so far is unique in bacterial chemotaxis.

Mol Plant Microbe Interact, 1998 Jan, 11(1), 71 - 5
Use of green fluorescent protein to detect expression of nif genes of Azoarcus sp . BH72, a grass-associated diazotroph, on rice roots; Egener T et al.; A gfp (green fluorescent protein) cassette for transcriptional fusions has been developed to study gene expression in Azoarcus sp . BH72 in association with plant roots . The bacteria expressed nitrogenase genes (nifHDK) in the rhizosphere, on root tips, and in epidermal cells of rice seedlings . Green fluorescent protein fusions also visualized promoter activity of single cells in soil.

Development, 1998 Feb, 125(3), 339 - 49
Nod factor internalization and microtubular cytoskeleton changes occur concomitantly during nodule differentiation in alfalfa; Timmers AC et al.; Reorganization of the plant cytoskeleton is thought to play an important role during nodule ontogeny . In situ immunolocalisation of tubulin reveals that important cytoskeletal changes, implying a transient disorganization followed by a newly patterned reorganization, occur in indeterminate and determinate nodules . In alfalfa nodules, cytoskeletal changes closely parallel the symbiotic differentiation features related to cell infection, bacterial release, endopolyploidization, cell enlargement, cell spatial organization and organelle ultrastructure and positioning . Moreover, the fact that microtubule disorganization can be correlated with Nod factor internalization in central infected cells suggests that Nod factors are possibly involved in the control of cytoskeletal changes which direct the differentiation of bacteria-containing cells.

Infect Immun, 1998 Jan, 66(1), 203 - 12
Induced expression of the Legionella pneumophila gene encoding a 20-kilodalton protein during intracellular infection; Abu Kwaik Y; The eukaryotic protein synthesis inhibitor cycloheximid has been used by many investigators to selectively radiolabel intracellular bacteria . Although cycloheximide has no direct effect on bacterial gene expression, there are concerns that long-term inhibition of the host cell protein synthesis may have secondary effects on bacterial gene expression . Therefore, prior to further identification and cloning of the macrophage-induced (MI) genes of Legionella pneumophila, the effects of cycloheximide on L . pneumophila-infected U937 cells were evaluated by transmission electron microscopy . Inhibition of protein synthesis of the host cell for 6 h had no major effect on the ultrastructure of the host cell, on the formation of rough endoplasmic reticulum-surrounded replicative phagosome, or on initiation of intracellular bacterial replication . In contrast, by 15 h of cycloheximide treatment, there was profound deterioration in the host cell as well as in the phagosome . To examine protein synthesis by L . pneumophila during the intracellular infection, U937 macrophage-like cells were infected with L . pneumophila, and intracellular bacteria were radiolabeled during a 2-h cycloheximide treatment or following 12 h of cycloheximide treatment . Comparison by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the protein profile of radiolabeled in vitro-grown L . pneumophila to that of intracellularly radiolabeled bacteria showed that 23 proteins were induced in response to the intracellular environment during 2 h of inhibition of host cell protein biosynthesis . Twelve MI proteins of L . pneumophila were artifactually induced due to prolonged inhibition of the host cell protein synthesis . The gene encoding a 20-kDa MI protein was cloned by a reverse genetics technique . Sequence analysis showed that the cloned gene encoded a protein that was 80% similar to the enzyme inorganic pyrophosphatase . Studies of promoter fusion to a promoterless lacZ gene showed that compared to in vitro-grown bacteria, expression of the pyrophosphatase gene (ppa) was induced fourfold throughout the intracellular infection . There was no detectable induction in transcription of the ppa promoter during exposure to stress stimuli in vitro . The ppa gene of L . pneumophila is the first example of a regulated ppa gene which is selectively induced during intracellular infection and which may reflect enhanced capabilities of macromolecular biosynthesis by intracellular L . pneumophila . The data indicate caution in the long-term use of inhibition of host cell protein synthesis to selectively examine gene expression by intracellular bacteria.

Infect Immun, 1998 Jan, 66(1), 65 - 9
In vivo regulation of replicative Legionella pneumophila lung infection by endogenous interleukin-12; Brieland JK et al.; The in vivo role of endogenous interleukin 12 (IL-12) in modulating intrapulmonary growth of Legionella pneumophila was assessed by using a murine model of replicative L . pneumophila lung infection . Intratracheal inoculation of A/J mice with virulent bacteria (10(6) L . pneumophila cells per mouse) resulted in induction of IL-12, which preceded clearance of the bacteria from the lung . Inhibition of endogenous IL-12 activity, via administration of IL-12 neutralizing antiserum, resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection (compared to untreated L . pneumophila-infected mice) . Because IL-12 has previously been shown to modulate the expression of cytokines, including gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and IL-10, which regulate L . pneumophila growth, immunomodulatory effects of endogenous IL-12 on intrapulmonary levels of these cytokines during replicative L . pneumophila lung infection were subsequently assessed . Results of these experiments demonstrated that TNF-alpha activity was significantly lower, while protein levels of IFN-gamma and IL-10 in the lung were similar, in L . pneumophila-infected mice administered IL-12 antiserum, compared to similarly infected untreated mice . Together, these results demonstrate that IL-12 is critical for resolution of replicative L . pneumophila lung infection and suggest that regulation of intrapulmonary growth of L . pneumophila by endogenous IL-12 is mediated, at least in part, by TNF-alpha.

J Mol Biol, 1997 Nov 21, 274(1), 39 - 53
Structure-function correlations in the XerD site-specific recombinase revealed by pentapeptide scanning mutagenesis; Cao Y et al.; Xer-mediated site-specific recombination contributes to the stability of circular chromosomes in bacteria by resolving plasmid multimers and chromosome dimers to monomers prior to cell division . Two related site-specific recombinases, XerC and XerD, each catalyse one pair of strand exchange during Xer recombination . In order to relate the recently determined structure of XerD to its function, the XerD protein was subjected to pentapeptide scanning mutagenesis, which leads to a variable five amino acid cassette being introduced randomly into the target protein . This has allowed identification of regions of XerD involved in specific DNA binding, in communicating with the partner recombinase, XerC, and in catalysis and its control . The C-terminal domain of XerD, comprising two-thirds of the protein, contains the catalytic active site and comprises ten alpha helices (alphaE to alphaN) and a beta hairpin . A flexible linker connects this domain to the N-terminal domain that comprises four alpha helices (alphaA to alphaD) . Pentapeptide insertions into alphaB, alphaD, alphaG, or alphaJ interfered with DNA binding . Helices alphaG and alphaJ comprise a pseudo helix-turn-helix DNA binding motif that may provide specificity of recombinase binding . An insertion in alphaL, adjacent to an active site arginine residue, led to loss of cooperative interactions between XerC and XerD and abolished recombination activity . Other insertions close to active site residues also abolished recombination activity . Proteins with an insertion in the beta hairpin turn bound DNA, interacted cooperatively with XerC and had a phenotype that is consistent with the protein being defective in XerD catalysis . This beta hairpin appears to be highly conserved in related proteins . Insertions at a number of dispersed locations did not impair XerD catalytic activity or DNA binding, but failed to allow XerC catalysis in vivo, indicating that several sites of interaction between XerD and XerC may be important for activation of XerC catalysis by XerD .

Biochemistry, 1997 Dec 9, 36(49), 15343 - 8
The cyanobacterial repressor SmtB is predominantly a dimer and binds two Zn2+ ions per subunit; Kar SR et al.; The Synechococcus PCC7942 metallothionein repressor gene smtB has been cloned into a high expression vector and the protein purified to near homogeneity (>/=98%) . Analytical ultracentrifugation studies demonstrate that the protein is predominantly dimeric in 0.1 M NaCl, pH 7.4, and 22 degrees C, exhibiting a monomer-dimer-tetramer equilibrium . The monomer-dimer (Ka(1,2)) and the dimer-tetramer (Ka(2,4)) association constants are 3.24 x 10(5) and 9.90 x 10(2) M-1, respectively . The repressor binds two Zn2+ ions per subunit with an overall Kd of 3.49 x 10(-6) M . In the presence of Zn2+, Ka(1, 2) increases by 2 orders of magnitude to 1.25 x 10(7) M-1 and the apparent weight-averaged sedimentation coefficient increases from 2 . 00 to 2.22 S . The fact that the increase in sedimentation coefficient is greater than that predicted by increased dimerization is interpreted as caused by compaction of the structure in the presence of metal ions . At pH 6.0, 0.1 M NaCl, and 22 degrees C, the protein exhibits only a monomer-dimer equilibrium, with Ka(1,2) = 1.52 x 10(7) M-1 which is almost identical to that seen upon binding Zn2+ at pH 7.4 . The compaction and conformational change in SmtB caused by Zn2+ is consistent with a role for this altered quaternary state in derepression of smtA in Synechococcus challenged with heavy metal ions.

Infect Dis Clin North Am, 1997 Dec, 11(4), 905 - 28
Drug resistance in tuberculosis; Parsons LM et al.; Drug-resistant tuberculosis remains a worldwide problem . New laboratory methods have improved our ability to more rapidly identify resistant strains, but the most effective approach is to prevent the appearance of resistance by appropriate choice of antibiotics and directly-observed therapy . Mycobacterium tuberculosis is treated with familiar and unique drugs; consequently, mechanisms of resistance have some unique features . All drug resistance thus far identified develops by mutational events rather than acquisition of resistance genes from other bacteria . An agenda is presented for countering the appearance of further drug resistance in mycobacteria.

Acta Anaesthesiol Scand Suppl, 1997, 111, 253 - 6
Animal models for blood transfusion: a model for sterile blood sampling in the rat; Fitzgerald RD et al.; Rat blood is frequently used for experimental transfusion . However, no data are available concerning the quality of the blood used, although bacterial contamination could severely alter results . To obtain large quantities of sterile rat blood for a transfusion study, we tested carotid artery cannulation, known as a standard procedure . Blood cultures from the collected blood showed polymicrobial overgrowth even after sterility measures were improved . In contrast, the puncture of the abdominal aorta proved to be a simple and reliable method for the collection of sterile blood . We conclude that studies using blood collected from donor rats should be controlled and the quality of such blood be tested before transfusion.

J Virol, 1998 Jan, 72(1), 578 - 84
A defective interference-like phenomenon of human hepatitis B virus in chronic carriers; Yuan TT et al.; Defective interfering (DI) particles have been found in many RNA and DNA viruses of bacteria, plants, and animals since their first discovery in influenza virus . However, this fundamental phenomenon has not been demonstrated in human natural infections . Using a new approach, here we provide the first experimental evidence for the existence of DI-like viruses in human chronic carriers of hepatitis B virus (HBV) . Functional characterization of naturally occurring core internal deletion (CID) variants of HBV revealed all of the features of DI particles . When equal amounts of wild-type and CID variant DNAs were cotransfected into a human hepatoma cell line, Huh7, a three- to fivefold enrichment of CID variants was most often observed . The fluctuations of the virus populations between CID variants and helper HBV in three chronic carriers are reminiscent of the cycling phenomenon in other DI viral systems . This finding has important implications for chronic viral hepatitis and other chronic progressive viral diseases.

Clin Exp Allergy, 1997 Nov, 27(11), 1270 - 8
Asthma among secondary schoolchildren in relation to the school environment; Smedje G et al.; BACKGROUND: Poor indoor air quality has been suggested to be related to the increase in the prevalence of asthma that has occurred in the western world, especially among children and young persons . Apart from the home, school is the most important indoor environment for children . OBJECTIVES: The aims were to study the prevalence of current asthma among secondary pupils and its relationship to the school environment, but also to personal factors and domestic exposures . METHODS: Data on asthmatic symptoms, other health aspects, and domestic exposures were gathered using a questionnaire which was sent to 762 pupils in the seventh form (13-14 years old) in 11 randomly chosen schools in the county of Uppsala in Sweden . Pupils answering 'yes' to having had asthma diagnosed by a physician, and having had recent asthma attacks, or who used asthma medication were defined as having current asthma . Data on exposures at school were gathered by measurements in 28 classrooms . The relationship between asthma and exposures was analysed by multiple logistic regression . RESULTS: The questionnaire was completed by 627 (82%) . Current asthma was found among 40 pupils (6.4%) . Current asthma was more common in those who had an atopic disposition, or food allergy, or who had attended a day care centre for several years . Controlling for these factors, current asthma was related to several factors in the school environment . There were more pupils with current asthma in schools that were larger, had more open shelves, lower room temperature, higher relative air humidity, higher concentrations of formaldehyde or other volatile organic compounds, viable moulds or bacteria or more cat allergen in the settled dust . CONCLUSIONS: Although the pupils attended school for a minor part of their time, our study indicates that the quality of the school environment is of importance and may affect asthmatic symptoms.

FEMS Microbiol Lett, 1997 Dec 1, 157(1), 207 - 17
Comparison of the abilities of proteins from Bartonella bacilliformis and Bartonella henselae to deform red cell membranes and to bind to red cell ghost proteins; Iwaki-Egawa S et al.; Infections in humans by Bartonella bacilliformis, but not Bartonella henselae, are characterized by invasion of red cells . Supernatants of culture medium from B . bacilliformis and B . henselae each contain a protein which causes invagination of membranes of human red cells and formation of intracellular vacuoles . These two proteins are very similar in molecular mass, heat stability and mechanism of action . B . henselae does not bind to human red cells, but human red cell ghost membrane proteins were recognized by both bacteria, five by B . bacilliformis and the same five, and one additional protein by B . henselae . Two of these proteins had molecular masses consistent with actin and spectrin . Actin binds to five electroblotted outer membrane proteins from B . henselae and four of these proteins are retained on an actin-Sepharose column.

Semin Ultrasound CT MR, 1997 Dec, 18(6), 448 - 59
Orbital infections; Hershey BL et al.; Orbital infections account for the majority of primary intraorbital disease processes . Sinusitis is the most common etiology . Five stages of cellulitis secondary to sinusitis have been described . Systemic conditions which predispose to orbital infection include diabetes, septicemia, malignancy, and immunosuppresion . Clinical signs and symptoms include superficial inflammatory changes, as well as proptosis, limitation of extraocular motility, and visual loss . Causative agents are most commonly bacteria, with fungus, viruses, and parasites seen less frequently . Imaging is performed by CT and/or MRI which are complementary in certain cases . Differential diagnosis of imaging abnormalities includes inflammatory and granulomatous diseases, as well as neoplasm.

J Exp Med, 1997 Dec 1, 186(11), 1843 - 51
Atypical disease after Bordetella pertussis respiratory infection of mice with targeted disruptions of interferon-gamma receptor or immunoglobulin mu chain genes; Mahon BP et al.; Using a murine respiratory challenge model we have previously demonstrated a role for Th1 cells in natural immunity against Bordetella pertussis, but could not rule out a role for antibody . Here we have demonstrated that B . pertussis respiratory infection of mice with targeted disruptions of the genes for the IFN-gamma receptor resulted in an atypical disseminated disease which was lethal in a proportion of animals, and was characterized by pyogranulomatous inflammation and postnecrotic scarring in the livers, mesenteric lymph nodes and kidneys . Viable virulent bacteria were detected in the blood and livers of diseased animals . An examination of the course of infection in the lung of IFN-gamma receptor-deficient, IL-4-deficient and wild-type mice demonstrated that lack of functional IFN-gamma or IL-4, cytokines that are considered to play major roles in regulating the development of Th1 and Th2 cells, respectively, did not affect the kinetics of bacterial elimination from the lung . In contrast, B cell-deficient mice developed a persistent infection and failed to clear the bacteria after aerosol inoculation . These findings demonstrate an absolute requirement for B cells or their products in the resolution of a primary infection with B . pertussis, but also define a critical role for IFN-gamma in containing bacteria to the mucosal site of infection.

J Cell Biol, 1997 Dec 1, 139(5), 1089 - 95
The human DnaJ homologue dj2 facilitates mitochondrial protein import and luciferase refolding; Terada K et al.; DnaJ homologues function in cooperation with hsp70 family members in various cellular processes including intracellular protein trafficking and folding . Three human DnaJ homologues present in the cytosol have been identified: dj1 (hsp40/hdj-1), dj2 (HSDJ/hdj-2), and neuronal tissue-specific hsj1 . dj1 is thought to be engaged in folding of nascent polypeptides, whereas functions of the other DnaJ homologues remain to be elucidated . To investigate roles of dj2 and dj1, we developed a system of chaperone depletion from and readdition to rabbit reticulocyte lysates . Using this system, we found that heat shock cognate 70 protein (hsc70) and dj2, but not dj1, are involved in mitochondrial import of preornithine transcarbamylase . Bacterial DnaJ could replace mammalian dj2 in mitochondrial protein import . We also tested the effects of these DnaJ homologues on folding of guanidine-denatured firefly luciferase . Unexpectedly, dj2, but not dj1, together with hsc70 refolded the protein efficiently . We propose that dj2 is the functional partner DnaJ homologue of hsc70 in the mammalian cytosol . Bacterial DnaJ protein could replace mammalian dj2 in the refolding of luciferase . Thus, the cytosolic chaperone system for mitochondrial protein import and for protein folding is highly conserved, involving DnaK and DnaJ in bacteria, Ssa1-4p and Ydj1p in yeast, and hsc70 and dj2 in mammals.

Parasite Immunol, 1997 Oct, 19(10), 475 - 83
Evidence for direct interaction between mast cells and Leishmania parasites; Bidri M et al.; When stimulated through IgE-(or IgG-) immune complexes with parasite antigens, mast cells can release several cytokines, including IL-4, IL-6, IL-10, IL-12, Interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) that may influence the host response to Leishmania major in modulating lesion size and persistence during experimental infection in the mouse . Moreover, recent data demonstrated that mast cells are able to be antibody-independently activated by direct contact with bacteria, making them important elements in innate immunity . Given these data, we asked whether cell-parasite contact could directly induce mast cell mediator release and whether mast cells could be infected by L . major or L . infantum parasites . In this study, we showed that a pure homogeneous population of mouse bone marrow derived mast cells (BMMC) in contact with living L . major or L . infantum promastigotes, but not with attenuated parasites or soluble parasite antigens, released preformed mediators such as beta-hexosaminidase and the preformed pool of TNF-alpha within minutes . Furthermore, direct cell-parasite contact induced TNF-alpha synthesis by mast cells within hours . Moreover, we demonstrated by in vitro co-culture experiments that metacyclic L . major or L . infantum promastigotes are directly infective for a significant proportion of BMMC and are transformed into intracellular amastigotes . Taken together, these data suggest that mast cell can participate in the first line of defence, i.e . innate immunity, during local cutaneous infection with Leishmania parasites.

Pediatr Pulmonol, 1997 Nov, 24(5), 324 - 30
Pulmonary diseases in children with severe combined immune deficiency and DiGeorge syndrome; Deerojanawong J et al.; Pulmonary disease is a common presenting feature and complication of T-cell immunodeficiency . We retrospectively reviewed 15 children with severe combined immune deficiency (SCID) and 19 children with DiGeorge syndrome at the time of their first presentation to the Royal Children's Hospital in the 15-year period from 1981 to 1995 . In children with SCID, pulmonary disease was a common (67%) presenting feature and the organisms identified were Pneumocystis carinii (PCP) (n = 7), bacteria (n = 4), viruses (n = 3), and a fungus (n = 1) . Late pulmonary complications included lower respiratory tract infections, bronchiolitis obliterans, and lymphointerstitial pneumonitis . Pulmonary infections were common (17 occasions) and the organisms identified were bacteria (n = 7), viruses (n = 6), fungi (n = 3), and Mycobacterium tuberculosis (n = 1) . Pulmonary complications were responsible for 5 of 9 deaths . PCP was not identified as a late complication in any child, presumably as a result of effective prophylactic therapy . Although pulmonary disease was not a major presenting feature in children with DiGeorge syndrome, pulmonary complications were common . These included recurrent bacterial and viral infections and bronchomalacia, which complicated management and predisposed to morbidity and mortality, even in those without a T-cell defect . We conclude that pulmonary disease is a common manifestation in children with SCID and DiGeorge syndrome.

Rev Reprod, 1996 Jan, 1(1), 28 - 32
Identification of early pregnancy factor as chaperonin 10: implications for understanding its role; Cavanagh AC; Early pregnancy factor (EPF) is a secreted substance with growth regulatory and immunomodulatory properties . It is required for successful establishment of pregnancy and for proliferation of both normal and neoplastic cells, in vivo and in vitro . The rosette inhibition test was used as a bioassay, and the appearance of EPF in serum in the very early stages of pregnancy (in mice, within 4-6 h of mating) was first described two decades ago . However, because of the difficulty of this bioassay and the paucity of EPF in biological materials, the primary structure of the molecule has been identified only recently . Seventy per cent of the amino acid sequence of EPF derived from human platelets was determined . With the exception of a single residue, this was identical to the sequence of rat mitochondrial chaperonin 10 (cpn10) . Cpn10 is a heat shock protein that functions as a molecular chaperone . It binds to and stabilizes cpn60 and, in concert, these molecules mediate protein folding in mitochondria, chloroplasts and bacteria . Characterizing EPF as an extracellular form of cpn10 raises unprecedented questions about the mechanism of action . It may be that, as a molecular chaperone in the extracellular compartment, EPF can functionally modify other proteins, serving as a regulator of regulators.

Proteins, 1997 Dec, 29(4), 562 - 74
Primary structure of the common polypeptide chain b from the multi-hemoglobin system of the hydrothermal vent tube worm Riftia pachyptila: an insight on the sulfide binding-site; Zal F et al.; The deep-sea tube worm Riftia pachyptila Jones possesses a multi-hemoglobin system with three different extracellular Hbs: two dissolved in the vascular blood, V1 (ca . 3,500 kDa) and V2 (ca . 400 kDa), and one in the coelomic fluid, C1 (ca . 400 kDa) . V1 Hb consists of four heme-containing, globin chains (b-e) and four linker chains (L1-L4) . V2 and C1 Hbs are exclusively built from globin chains, six for V2 (a-f) and five for C1 (a-e) . The complete amino acid sequence of the isolated monomeric globin chain b, common to all Riftia Hbs, has been determined by automated Edman degradation sequencing of the peptides derived by digestion with trypsin, chymotrypsin, thermolysin, and CNBr . This polypeptide chain is composed of 144 amino acid residues, providing a M(r) of 16, 135.0 Da . Moreover, the primary sequence of chain b revealed 3 Cys residues at position 4, 75, and 134 . Cys-4 and Cys-134 are located at positions where an intra-chain disulfide bridge is formed in all annelid, vestimentiferan, or pogonophoran chains, but Cys-75 is located at a unique position only found in three globin chains belonging to Lamellibrachia and Oligobrachia, a vestimentiferan and a pogonophoran . In both groups, Hbs can bind sulfide reversibly to fuel the chemosynthetic process of the symbiotic bacteria they harbor . Sulfide-binding experiments performed on purified Hb fractions (i.e., V1, V2, and C1 Hbs) suggest that free Cys residues on globin chains, and the numerous Cys found in linker chains, as determined previously by ESI-MS, may be the sulfide binding-sites . Blocking the free Cys by N-ethylmaleimide, we confirmed that free cysteines were involved in sulfide-binding but did not account for the whole sulfide-binding capacity of V1 Hb . Furthermore, a phylogenetic tree was constructed from 18 globin-like chains of annelid, vestimentiferan, and pogonophoran extracellular Hbs to clarify the systematic position of tubeworms . Riftia chain b clearly belongs to the "strain A" family with 30 to 80% identity with the other sequences analyzed . Its position in the tree confirmed a close relationship between vestimentiferan, pogonophoran, and annelid Hbs.

Vaccine, 1997 Dec, 15(17-18), 1955 - 8
Two primary doses of diphtheria-tetanus-acellular pertussis vaccine induce immunological responses to Bordetella pertussis as strong as those induced by three primary doses; Tomoda T et al.; Pertussis vaccinations are administered worldwide under various conditions and schedules with diphtheria-tetanus-pertussis (DTP) . In Japan, a general vaccination with three primary doses of diphtheria-tetanus-acellular pertussis (DTaP) at 4-week intervals and one booster dose 12 months after the primary series have been used since 1981 . Decreasing the number of doses of the vaccination would lessen the physical and economic costs . To compare the immunological response to two versus three primary doses, we assessed antibody and cellular immune responses in health children . The anti-filamentous hemagglutinin (anti-FHA) and anti-pertussis toxin (anti-PT) antibody responses to two primary doses of DTaP before a booster were significantly lower than the responses to three primary doses . Although these antibody levels were low in children who received two primary doses, the FHA-induced DNA synthesis was equal to that of the children who received three doses . The anti-FHA and anti-PT antibody levels 4 weeks after the booster following two doses were similar to the levels following three doses, and high antibody titers were maintained over a long period . In areas where contact with bacteria is expected, two primary doses of DTaP may be adequate to induce the necessary level of immunological responses.

Vaccine, 1997 Dec, 15(17-18), 1902 - 7
A comparison of antibody responses to veterinary vaccine antigens potentiated by different adjuvants; Usinger WR; Six adjuvant formulations were compared for their ability to potentiate the primary and memory antibody responses in mice to three companion animal vaccine immunogens--feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and a recombinantly-derived heartworm antigen . The combination of a novel bacterial immunostimulator, gliding bacterial adjuvant (GBA), either adsorbed onto an aluminum hydroxide gel (Rehydragel HPA), or emulsified with a vehicle of polyalcohol and detergent, elicited the strongest memory responses to both virus preparations . Both forms of aluminum hydroxide gels administered without GBA gave similar levels of adjuvant effects, on par with or greater than those generated by incomplete Freund's adjuvant (IFA) . The Acemannan immunostimulant was not effective in increasing the responses to the virus antigens, but increased the primary response to the heart-worm antigen over tenfold from control levels . All preparations appeared to be well tolerated, with no detectable adverse reactions observed in any of the 250 mice used . The proven safety of aluminum hydroxide adjuvants and the apparent absence of adverse reactions seen with GBA make this vehicle/adjuvant formulation worthy of additional study.

Am J Respir Crit Care Med, 1997 Dec, 156(6), 1719 - 24
Effects of an immunostimulating agent on acute exacerbations and hospitalizations in patients with chronic obstructive pulmonary disease . The PARI-IS Study Steering Committee and Research Group . Prevention of Acute Respiratory Infection by an Immunostimulant; Collet JP et al.; The PARI-IS Study is a double-blind placebo-controlled randomized clinical trial to study the effect of an immunostimulating agent to prevent acute respiratory exacerbation in patients with COPD . Three hundred eighty-one ambulatory patients (190 placebo and 191 immunostimulant) were followed at home for 6 mo by experienced research nurses . The risk of having at least one episode of acute exacerbation (primary outcome) was similar in the two groups (p = 0.872) . In contrast, the total number of days of hospitalization for a respiratory problem was 55% less in the group treated with OM-85 BV (287 d) than in the group treated with placebo (642 d) . Patients treated with OM-85 BV spent an average of 1.5 d in hospital compared with 3.4 d for patients treated with placebo (p = 0.037) . The risk of being hospitalized for a respiratory problem was 30% lower in the treated group (16.2%) than in the placebo group (23.2%); p = 0.089 . Eight deaths were observed: two in patients treated with OM-85 BV and six in patients treated with placebo (p = 0.153) . During the course of the study dyspnea improved slightly in patients treated with OM-85 BV, whereas it deteriorated slightly in patients receiving placebo (p = 0.028) . These results suggest that this immunostimulating agent may be beneficial for patients with COPD by reducing the likelihood of severe respiratory events leading to hospitalization.

Lakartidningen, 1997 Oct 1, 94(40), 3487 - 8
{Does the infectious disease, human ehrlichiosis, exist in Sweden? Ticks get a hold of new zoonoses}; Eliasson I et al.; Human ehrlichiosis diseases, decently recognised as emerging human infections in the USA, are caused by vector-borne, strictly intracellular bacteria of the family Rickettsiaceae . Human monocytic ehrlichiosis is caused by Ehrlichia schaffeensis, whereas the agent causing human granulocytic ehrlichiosis (HGE) has yet to be identified {1} . The putative increase in the occurrence of these primary zoonoses is dependent on the complex relationship between the infectious agents, the vectors, and the hosts (rodents, deer) which constitute the wild-life reservoir . In Scandinavia, granulocytic ehrlichiosis is well known in veterinary medicine . Pasture fever in cattle and sheep is caused by Ehrlichia phagocytophila, whereas granulocytic ehrlichiosis in horses and dogs is caused by a new, recently characterised Ehrlichia species {2} . All species of Ehrlichia causing granulocytic ehrlichiosis are closely related both genetically and antigenically, and are all transmitted by ticks of the genus Ixodes . In Sweden, veterinary cases of granulocytic ehrlichiosis are characterised by a geographical distribution corresponding well with that of Ixodes ricinus, and a seasonal distribution similar to that of Lyme borreliosis . In Europe, clinical cases of HGE have so far been reported only from Slovenia {5}, though seroprevalence figures of 8-17 per cent have been reported for tick-exposed populations {6, 7} . As most cases are probably subclinical, and as clinical symptoms, when present, are non-specific, clinical diagnosis is dependent on the clinician's awareness of the existence of the disease . Laboratory diagnostic tests are now available at Kalmar.

Contracept Fertil Sex, 1997 Jul-Aug, 25(7-8), 592 - 5
{Current requirements of sterilization and disinfection of endoscopic materials}; Traore O et al.; Bacterial and viral infectious risks related to gynecologic endoscopy and laparoscopy are a significant problem . Contamination between patients or by environmental bacteria can occur when sterilisation or disinfection procedures are inadequate . Endoscope steam sterilisation is the safest method and have to be employed whenever possible . For heat labile materials, disinfection procedure will comply with the recommendations stated in a recent ministerial decision, including a cleaning step with a non aldehydic detergent-disinfectant and a disinfection step with 2% glutaraldehyde . Rooms and equipment dedicated to disinfection have to be well adapted to this use and specific staff training must be achieved . Endoscope automatic washer disinfections are an alternative method to manual disinfection but they have to meet precise criteria to insure safety and efficacy.

Zentralbl Hyg Umweltmed, 1996 Dec, 199(2-4), 227 - 39
{Toxicologic risk assessment and prevention: rational and irrational approaches}; Forth W; Worldwide, the management and evaluation of risks caused by chemical compounds are handled by the aid of threshold concentrations below of which one can be sure that no biological effect whatsoever can be observed . At the working place, we use the maximally tolerated concentration of the chemicals (MAK) and, in addition, the biologically tolerated concentrations (BTC) of the compounds either in blood or in other body fluids to which a male and/or female worker is exposed . These threshold concentrations should cover any toxic effect including on the one hand mere deviations of clinical chemical values without a disturbed function, i.e . symptoms of a disease as well as, on the other hand, carcinogenic, mutagenic and even allergic effects . Threshold concentrations, however, exist only for acute and chronic toxic effects and not for carcinogenic and/or mutagenic effects . In these cases, again, worldwide, the concept of minimizing the risks by the exposure is preferred since no toxicologist can be found to assure a "safe" concentration of a chemical compound that exert carcinogenic and/or mutagenic effects . With respect to these effects a proven carcinogenic and/or mutagenic effect in human beings must be discerned from a suspected effect on the basis of animal experiments or in vitro models . However, there exist also paradigms of a clearcut connection between a chemical substance or its metabolites causing carcinogenic and/or mutagenic effects in model experiments from which a clearcut suspect of similar reactions after the exposure of human beings can be drawn . In general, carcinogenic risks are overestimated in our societies . Following the data of experienced British epidemiologist most tumor diseases can be traced back to food consumption, beverages and tobacco and even sexual behavior must be ranked as cause for tumors before the rare exposure to dangerous chemicals at the working place . It is worthwhile to mention that natural toxins produced by bacteria and even infectious diseases or diseases caused by parasites are far more serious than the exposure to any man made chemical product including the Seveso poison, i.e . 2,3,7,8-TCDD, and related compounds . Vice-versa, the assumption that naturally occurring poisons could be neglected may lead to fatal experiences as for instances the outbreak of St-Anton's fire, i.e . the gangraeneous type of ergot alacaloide intoxication after having swallowed claviceps purpurea poisoned "Musli" produced by rye collected in the fields and ground in a hand mill . In Middle-Europe, since 1880, when the threshold of 0.1% claviceps purpurea in rye was established, no poisonous epidemia of St . Anton's fire was observed.

Arterioscler Thromb Vasc Biol, 1997 Nov, 17(11), 2369 - 75
Scavenger receptors are present on rabbit aortic endothelial cells in vivo; Daugherty A et al.; Endothelial cells metabolize modified LDL, but attempts to detect scavenger receptors in this cell type in vitro have been unsuccessful . To determine whether scavenger receptors are present on endothelial cells in vivo, species-specific reagents were developed to detect rabbit scavenger receptor protein . Antiserum against the rabbit scavenger receptor was generated with the use of synthetic peptides of two distinct regions: residues 3 to 21 in the cytoplasmic tail and residues 282 to 304 in the collagen-like region . Reactivity of antiserum against the synthetic peptides was confirmed with an enzyme-linked immunosorbent assay . Positive reactivity was also observed against fragments of scavenger receptor protein expressed in bacteria . Antiserum to both regions reacted with liver membrane proteins of sizes consistent with the scavenger receptor, as confirmed by Western blotting under reduced and nonreduced conditions . Immunocytochemical examination of rabbit aortic tissue by use of antiserum to both regions of scavenger receptor protein produced striking and identical patterns of staining of aortic endothelium . Immunostaining was abolished for both antisera by preadsorption with the specific peptide region used as immunogen . In contrast, incubation of scavenger receptor antiserum with a peptide of a region of the rabbit LDL receptor failed to influence immunoreactivity against endothelium . These data demonstrate the presence of scavenger receptors in rabbit endothelium in vivo, which may have fundamental implications for lipoprotein metabolism by the arterial wall.

Aust Dent J, 1997 Oct, 42(5), 302 - 6
The current status of low level laser therapy in dentistry . Part 2 . Hard tissue applications; Walsh LJ; While most applications of low level laser therapy (LLLT) in dentistry are directed toward soft tissues, in recent years there has been increasing interest in tooth-related or hard tissue applications of LLLT . This report provides an overview of applications of LLLT in the treatment of dentine hypersensitivity and pain arising from the periodontal ligament, and describes the phenomenon of lethal laser photosensitization and its applications in the treatment of dental caries . Technical aspects of LLLT equipment and safety concerns are also discussed.

Australas Phys Eng Sci Med, 1997 Sep, 20(3), 125 - 38
Beneficial effects of radiation and regulatory policy; Jaworowski Z; Adaptive and stimulating effects of ionizing radiation occur at near natural doses . This disagrees with linear, no-threshold hypothesis on the dose/effect relationship, which is a basis of the current radiation protection . Vast literature demonstrates that such effects, usually known as hormetic ones, occur at molecular, cellular and population levels, and often result in increase longevity and decreased cancer incidence . Exposure to lower than natural radiation causes deficiency symptoms in protozoa and bacteria . Hormetic effects suggest that the current radiation protection regulations may be too conservative . After the Chernobyl accident, adverse health effects and vast material losses were induced in the former USSR by practical implementation of the ICRP radiation protection recommendations . A revision of the current approach to managing the risks of ionizing radiation is needed for the public interest.

Scand J Rheumatol, 1997, 26(5), 342 - 5
Serological findings in patients with acute syndromes fulfilling the proposed criteria of adult onset Still's disease; Valtonen JM et al.; In order to analyse possible triggering or contributing infections and HLA-B27 frequency in patients with acute febrile joint syndrome fulfilling the proposed criteria of adult Still's disease (AOSD), we studied prospectively the serological findings of 25 patients . They were aged 15-62 years and diagnosed between 1978-1992 . We then compared results with a control group consisting of 119 healthy persons . Positive viral or bacterial serology was found in 12 patients (48%) in the AOSD group compared with 13 cases (11%) in the control group (p < 0.001) . Fourfold or higher viral antibody rise was found in two patients and bacterial antibody rise in three patients . High stable viral antibody titre was observed in one patient and high stable bacterial antibody titre in six patients . HLA-B27 was not overrepresented in the study group (12%) compared with a healthy Finnish population (14%) . We conclude that many different bacterial and viral infections may trigger or contribute to AOSD.

Acta Orthop Scand, 1997 Oct, 68(5), 466 - 9
Orthopedic wound infections . 182 cases after 8913 operations during an 8-year survey; Sorensen TS et al.; We performed a surveillance of postoperative wound infections at our department for a period of 8 years . The surveillance was based on forms completed by the surgeons at the department . Retrospectively, by scrutinizing the records of patients with recorded infections, the criteria for infections used by the surgeons were compared with the criteria recommended by the Centers for Disease Control, USA, for routine infection surveillance studies: 1) pus present in the wound, 2) bacteria isolated from the wound, 3) spontaneous wound breakdown or surgical intervention due to suspected infection; if culture is performed, it must be positive, 4) evidence of infection at reoperation or at radiologic or histopathologic examination (restricted to deep infections) or 5) diagnosis of infection by a surgeon . 182 infections were recorded; in 106 (58%) pus was present, drained either spontaneously or by surgical intervention, in 24 (13%) no pus was seen, but the culture was positive . In 116 cases, surgical intervention was performed or wounds spontaneously broke down; pus was found in 101 of these and culture of non-purulent material was positive in 13 and negative in 2 . In 52 (29%) patients, only criterion 5 was fulfilled . In surveillance studies where the recordings are based on several observers, the subjective criterion 5 may, as in our study, give a falsely high number of infections, also preventing comparison between studies . We recommend that all suspected infections are cultured and that only criteria 1, 2 and 4 are used.

Am J Physiol, 1997 Nov, 273(5 Pt 1), L913 - 20
Glycosylation differences between a cystic fibrosis and rescued airway cell line are not CFTR dependent; Jiang X et al.; Altered glycosylation of mucus and membrane glycoconjugates could explain reported differences in binding of bacterial pathogens to cystic fibrosis (CF) versus normal tissue . However, because bacteria can alter cell surface glycoconjugates, it is not possible to assess the role of cystic fibrosis transmembrane conductance regulators (CFTR) in glycosylation in these studies . To address this issue, we have developed quantitative lectin binding assays to compare cell surface glycosylation in well-matched immortalized CF cells and rescued cell lines . The CF airway bronchial epithelial cell line IB3-1 consistently bound more peanut agglutinin (PNA) than its clonal derivative S9, which stably expresses functional wild-type CFTR . Pretreatment with neuraminidase increased PNA binding and abolished the difference between the two cell lines . However, infection of the IB3-1 cells with a replication-deficient recombinant adenovirus encoding CFTR restored CFTR function but did not alter PNA binding to cells . In contrast, treatment with the weak base ammonium chloride increased PNA binding to both cell lines as expected . Our data show that even clonally related CF and rescued cells can exhibit significant differences in carbohydrate processing . Although the differences that we found are consistent with the proposed role for CFTR in modulating intraorganellar pH, our data strongly suggest that they are CFTR independent . These studies add a cautionary note to the interpretation of differences in glycosylation between CF and normal primary tissues and immortalized cells.

Mol Cell Biol, 1997 Dec, 17(12), 7061 - 8
The yeast silent information regulator Sir4p anchors and partitions plasmids; Ansari A et al.; Circular plasmids containing telomeric TG1-3 arrays or the HMR E silencer segregate efficiently between dividing cells of the yeast Saccharomyces cerevisiae . Subtelomeric X repeats augment the TG1-3 partitioning activity by a process that requires the SIR2, SIR3, and SIR4 genes, which are also required for silencer-based partitioning . Here we show that targeting Sir4p to DNA directly via fusion to the bacterial repressor LexA confers efficient mitotic segregation to otherwise unstable plasmids . The Sir4p partitioning activity resides within a 300-amino-acid region (residues 950 to 1262) which precedes the coiled-coil dimerization motif at the extreme carboxy end of the protein . Using a topology-based assay, we demonstrate that the partitioning domain also retards the axial rotation of LexA operators in vivo . The anchoring and partitioning properties of LexA-Sir4p chimeras persist despite the loss of the endogenous SIR genes, indicating that these functions are intrinsic to Sir4p and not to a complex of Sir factors . In contrast, inactivation of the Sir4p-interacting protein Rap1p reduces partitioning by a LexA-Sir4p fusion . The data are consistent with a model in which the partitioning and anchoring domain of Sir4p (PAD4 domain) attaches to a nuclear component that divides symmetrically between cells at mitosis; DNA linked to Sir4p by LexA serves as a reporter of protein movement in these experiments . We infer that the segregation behavior of telomere- and silencer-based plasmids is, in part, a consequence of these Sir4p-mediated interactions . The assays presented herein illustrate two novel approaches to monitor the intracellular dynamics of nuclear proteins.

Mutat Res, 1997 Oct, 385(1), 21 - 9
A role for p53 in DNA end rejoining by human cell extracts; Bill CA et al.; The tumor suppressor p53 is a major regulator in the response of human cells to DNA damage . In this study we assessed the role of p53 in the repair of DNA double-strand breaks in plasmid DNA using cell extracts from three human lymphoblastoid cell lines derived from the same donor . TK6, WI-L2-NS and TK6-E6-5e cells express wild-type, mutated and essentially no p53 protein, respectively . Total cellular extracts from TK6, WI-L2-NS and TK6-E6-5e cells were incubated with EcoRI linearized pUC19 DNA . Southern blot analysis of end-rejoined DNA indicated that the major products formed were linear multimers . There was approximately 2-fold greater end rejoining in WI-L2-NS and TK6-E6-5e extracts compared with TK6 extracts . Total DNA from end-rejoining reactions was purified and used to transform bacteria . Using the lacZ reporter gene as a measure of repair fidelity we found that misrepair, as indicated by white colonies, occurred at 4.1% to 6.5% of transformants, with no significant difference between the three cell lines . Gel analysis revealed that misrepair involved only deletions . Sequence analysis of 11 misrepaired products from each cell line showed 12 different deletions from 4 to 48 bp in length, but each cell line yielded similar product types . These results indicate that total cellular extracts from human lymphoblastoid cells lacking p53 or expressing mutated p53 have increased end-rejoining activity as compared with extracts from cells expressing wild-type p53 . However, the p53 status does not influence the ratio of misrepair:correct repair, or the type of misrepair events.

Am J Respir Crit Care Med, 1997 Nov, 156(5), 1536 - 40
Regional variability of lung inflammation in cystic fibrosis; Meyer KC et al.; Chest radiography in patients with cystic fibrosis (CF) frequently shows more severe changes in the upper lobes . We performed bronchoalveolar lavage (BAL) on 12 clinically stable, young adult patients with CF to determine whether inflammation varies significantly among geographically distinct areas of the lung . We found that absolute numbers of neutrophils were generally greater in BAL fluid from the upper lobe (25.7 +/- 7.9 x 10(5) neutrophils/ml {mean +/- SEM}) of the right lung than that obtained from the right lower lobe (6.8 +/- 2.8 x 10(5) neutrophils/ml; p < 0.01) . The mean value of unopposed neutrophil elastase activity in upper-lobe BAL fluid (227 +/- 91 nmol peptide hydrolyzed/ml/min) was also significantly greater than that in lower-lobe BAL fluid (84 +/- 43 nmol/peptide hydrolyzed/ml/ min; p < 0.01), and similar differences were found for myeloperoxidase activity and DNA content . Neutrophil influx and unopposed neutrophil elastase for a given region correlated inversely with lung function or percentage of ideal body weight, and upper-versus lower-lobe differences were more pronounced in subjects with better preservation of lung function . Our findings suggest that regional variation in inflammation must be considered when utilizing BAL to study lower respiratory tract inflammation in CF or to monitor responses to therapeutic interventions that can potentially diminish lung inflammation . Our findings may also have implications for the study of the natural history of lung inflammation and infection in neonates, infants, and young children with CF.

Inflamm Res, 1997 Oct, 46(10), 382 - 91
Tissue injury in neutrophilic inflammation; Dallegri F et al.; The exudation of neutrophils is the hallmark of a form of inflammatory response occurring after tissue colonization by invading bacteria or as an expression of various non-infectious diseases . All these diseases are characterized by a high risk of developing irreversible tissue injury . Neutrophil-endothelium interactions, activation-induced functional and structural changes of responding neutrophils, regulatory systems of neutrophil function, and oxidative-proteolytic pathways responsible for histotoxicity are reviewed here . Finally, perspectives for rational approaches to handle the development of tissue injury during neutrophilic inflammation are considered.

Curr Opin Hematol, 1996 Sep, 3(5), 347 - 54
Platelet transfusion support for patients with cancer and hematologic malignancies; Sarkodee-Adoo C et al.; Advances in platelet transfusion have contributed to improved outcomes in the treatment of patients with cancer and leukemia . However, the optimal strategies to avoid some of the side effects that could result from platelet transfusions remain under investigation . These side effects include the development of refractoriness to transfusions, alloimmunization, transfusion reactions, the transmission of infectious agents, and transfusion-associated graft-versus-host disease . Leukodepletion by filtration is promising as a means of preventing the development of alloimmunization . Results of the Trial to Reduce Alloimmunization to Platelets will be reported shortly and will shed more light on that issue . Bedside filtration of cellular blood products also diminishes the transmission of cytomegalovirus infections by that route . Transfusion reactions are often mediated by cytokines in the plasma fraction of transfused platelet concentrates, and leukodepletion prior to storage reduces their incidence . Serious bacterial infections are sometimes transmitted by platelet transfusions and improved methods are needed for their detection and prevention . Photochemical methods that could inactivate bacteria and viruses in contaminated products deserve further study.

J Biol Chem, 1997 Nov 21, 272(47), 29911 - 8
A molecular basis for insulin resistance . Elevated serine/threonine phosphorylation of IRS-1 and IRS-2 inhibits their binding to the juxtamembrane region of the insulin receptor and impairs their ability to undergo insulin-induced tyrosine phosphorylation; Paz K et al.; Tumor necrosis factor alpha (TNFalpha) or chronic hyperinsulinemia that induce insulin resistance trigger increased Ser/Thr phosphorylation of the insulin receptor (IR) and of its major insulin receptor substrates, IRS-1 and IRS-2 . To unravel the molecular basis for this uncoupling in insulin signaling, we undertook to study the interaction of Ser/Thr-phosphorylated IRS-1 and IRS-2 with the insulin receptor . We could demonstrate that, similar to IRS-1, IRS-2 also interacts with the juxtamembrane (JM) domain (amino acids 943-984) but not with the carboxyl-terminal region (amino acids 1245-1331) of IR expressed in bacteria as His6 fusion peptides . Moreover, incubation of rat hepatoma Fao cells with TNFalpha, bacterial sphingomyelinase, or other Ser(P)/Thr(P)-elevating agents reduced insulin-induced Tyr phosphorylation of IRS-1 and IRS-2, markedly elevated their Ser(P)/Thr(P) levels, and significantly reduced their ability to interact with the JM region of IR . Withdrawal of TNFalpha for periods as short as 30 min reversed its inhibitory effects on IR-IRS interactions . Similar inhibitory effects were obtained when Fao cells were subjected to prolonged (20-60 min) pretreatment with insulin . Incubation of the cell extracts with alkaline phosphatase reversed the inhibitory effects of insulin . These findings suggest that insulin resistance is associated with enhanced Ser/Thr phosphorylation of IRS-1 and IRS-2, which impairs their interaction with the JM region of IR . Such impaired interactions abolish the ability of IRS-1 and IRS-2 to undergo insulin-induced Tyr phosphorylation and further propagate the insulin receptor signal . Moreover, the reversibility of the TNFalpha effects and the ability to mimic its action by exogenously added sphingomyelinase argue against the involvement of a proteolytic cascade in mediating the acute inhibitory effects of TNFalpha on insulin action.

J Biol Chem, 1997 Nov 21, 272(47), 29810 - 20
Regulation of phagosomal acidification . Differential targeting of Na+/H+ exchangers, Na+/K+-ATPases, and vacuolar-type H+-atpases; Hackam DJ et al.; Vacuolar-type (V) ATPases are thought to be the main determinant of phagosomal acidification . In phagosomes containing mycobacteria, which ostensibly impair the delivery of V-ATPases to the phagosomal membrane, the pH would be expected to be near neutral . This prediction was tested by microfluorescence ratio imaging using macrophages from mice susceptible to mycobacterial infection . Although less acidic than their counterparts containing dead bacteria, phagosomes containing live Mycobacteria bovis were nearly 1 pH unit more acidic than the cytosol, suggesting the existence of alternate H+ transport mechanisms . We therefore investigated whether Na+/H+ exchange (NHE) contributes to phagosomal acidification . Immunoblotting, reverse transcriptase-polymerase chain reaction, and pharmacological studies indicated that NHE1 is the predominant isoform of the exchanger in macrophages . Fractionation revealed that NHE1 is incorporated into the phagosomal membrane, and measurements of pH indicated that it is functional in this location . Nevertheless, acidification of the lumen of phagosomes containing either latex beads or live M . bovis was insensitive to (3-methylsulfonyl-4-piperidinobenzoyl)-guanidine methanesulfonate, a potent inhibitor of NHE1 . This may have been due to the absence of an appropriate lumen to cytosol Na+ gradient, because the phagosomal membrane was found to be devoid of Na+/K+ pumps . Unexpectedly, the acidification of M . bovis phagosomes was fully reversed by specific inhibitors of the vacuolar H+-ATPase, suggesting that ATPases are present only transiently or in reduced quantities in the phagosomal membrane . Alternatively, acid equivalents accumulated in endosomes by V-ATPases may be delivered to the mycobacterial phagosome by carrier vesicles devoid of ATPases.

Hand Clin, 1997 Nov, 13(4), 745 - 60
Infection in the presence of skeletal fixation in the upper extremity; McClinton MA et al.; Infection is infrequent after open fractures of the upper extremity . Treatment begins with prevention through the appropriate use of prophylactic antibiotics, adequate wound debridement, and timely soft-tissue coverage . If infection supervenes, the surgeon must identify the responsible bacteria and administer antibiotics accordingly . Stable fixation is retained . Unstable fixation is removed and skeletal stability restored . Using these principles, infection in the presence of skeletal fixation can be controlled and fracture union achieved.

DNA Cell Biol, 1997 Nov, 16(11), 1277 - 88
Use of a two-hybrid system to identify mutations in Max that confer increased affinity for Myc; Wang H et al.; A yeast two-hybrid system was used to identify mutants of Max that exhibit an increased affinity for Myc . Truncated forms of the Max helix-loop-helix/leucine zipper motif (HLH/Zip) were first expressed in a two- hybrid system in which the bait protein was the HLH/Zip motif of Myc . Deletion of amino acids both amino-terminal and carboxy-terminal to the leucine zipper of Max reduced Myc/Max heterodimer formation as evidenced by a 160-fold reduction in the expression of the lacZ gene . A library of partially randomized sequences encoding this minimal leucine zipper of Max was then screened using the two-hybrid system . Mutant forms of the Max leucine zipper were identified whose affinities for Myc, as measured by beta-galactosidase activity in yeast lysates, were from 8- to 200-fold greater than the wild-type Max zipper . These Max mutants were shown to interact specifically with Myc and not with wild-type Max . Of 29 mutants analyzed, all had a unique amino acid sequence . This result illustrates the value of a genetic screen in the identification of a collection of mutant forms of the Max leucine zipper whose structures would not have been predicted based on principles of structure-based design.

Appl Environ Microbiol, 1997 Dec, 63(12), 4975 - 7
Heat inactivation of Mycobacterium paratuberculosis in raw milk: are current pasteurization conditions effective?
Stabel JR, Steadham EM, Bolin CA.
Currently, it is not known whether commercial pasteurization effectively kills Mycobacterium paratuberculosis in contaminated raw milk . Results from holder test tube experiments indicated that a residual population of viable bacteria remained after treatment at 65, 72, 74, or 76 degrees C for 0 to 30 min . Use of a laboratory-scale pasteurizer unit demonstrated that treatment of raw milk at 72 degrees C for 15 s effectively killed all M . paratuberculosis.

Appl Environ Microbiol, 1997 Dec, 63(12), 4891 - 8
Degradation of tetrahydrofurfuryl alcohol by Ralstonia eutropha is initiated by an inducible pyrroloquinoline quinone-dependent alcohol dehydrogenase; Zarnt G et al.; An organism tentatively identified as Ralstonia eutropha was isolated from enrichment cultures containing tetrahydrofurfuryl alcohol (THFA) as the sole source of carbon and energy . The strain was able to tolerate up to 200 mM THFA in mineral salt medium . The degradation was initiated by an inducible ferricyanide-dependent alcohol dehydrogenase (ADH) which was detected in the soluble fraction of cell extracts . The enzyme catalyzed the oxidation of THFA to the corresponding tetrahydrofuran-2-carboxylic acid . Studies with n-pentanol as the substrate revealed that the corresponding aldehyde was released as a free intermediate . The enzyme was purified 211-fold to apparent homogeneity and could be identified as a quinohemoprotein containing one pyrroloquinoline quinone and one covalently bound heme c per monomer . It was a monomer of 73 kDa and had an isoelectric point of 9.1 . A broad substrate spectrum was obtained for the enzyme, which converted different primary alcohols, starting from C2 compounds, secondary alcohols, diols, polyethylene glycol 6000, and aldehydes, including formaldehyde . A sequence identity of 65% with a quinohemoprotein ADH from Comamonas testosteroni was found by comparing 36 N-terminal amino acids . The ferricyanide-dependent ADH activity was induced during growth on different alcohols except ethanol . In addition to this activity, an NAD-dependent ADH was present depending on the alcohol used as the carbon source.

Springer Semin Immunopathol, 1997, 19(2), 161 - 73
Genetic vaccination against tuberculosis; Lowrie DB et al.; New weapons are needed in the fight against tuberculosis . Recent research indicates that a vaccine better than BCG may be within reach . A diverse range of protein antigens can give encouragingly high levels of protective immunity in animal models when administered with adjuvants or as DNA vaccines . Accelerated arrest of bacterial multiplication followed by sustained decline in bacterial numbers are key parameters of protection and so the vaccine must target antigens produced by both actively multiplying and growth-inhibited bacteria . Consistent with this, the protective antigens have been found among secreted and stress proteins (e.g . Ag85, ESAT-6, hsp65, hsp70) . Species-specific antigens are not needed, hence these remain available for diagnostic tests . Adoptive transfer of protection from vaccinated or infected mice into naive mice by transfer of purified T cells and clones shows that protection is expressed by antigen-specific cytotoxic T cells that produce interferon-gamma and lyse infected macrophages . These cells are produced in response to endogenous antigen . DNA vaccination appears to be an excellent way of generating these cells and may be able to give long-lasting protection.

Thorax, 1997 Oct, 52(10), 929 - 31; discussion 926-7
Markers of inflammation in induced sputum in acute bronchitis caused by Chlamydia pneumoniae; Pizzichini MM et al.; Little is known of the inflammatory characteristics of acute infections of the respiratory tract caused by virus and unusual bacteria such as Chlamydia pneumoniae . A case is reported in whom inflammatory indices in sputum were used to investigate, for the first time, the airway inflammation during an episode of acute bronchitis caused by C pneumoniae . The patient presented with a dry cough of five days duration . C pneumoniae was identified by polymerase chain reaction (PCR) in a nasopharyngeal swab collected on day 5 . Virological studies were negative . Clinical and inflammatory indices in induced sputum were measured on days 6, 8, and 11 . The cough cleared spontaneously by day 11 . Forced expiratory volume in one second was normal throughout . Sputum findings identified intense airway inflammation characterised by increased total cell and lymphocyte counts followed by an increase in neutrophils and a decrease in the CD4/CD8 ratio, activation of CD8 lymphocytes, and exudation as indicated by an increase in fluid phase fibrinogen . These observations suggest that sputum might be useful to monitor an inflammatory/immune response of the airway in acute infections.

Dermatology, 1997, 195 Suppl 2, 78 - 84
Antiseptic effect of povidone-iodine solution on abdominal skin during surgery and on thyroid-gland-related substances; Shindo K; No definite guidelines have been published concerning the suitable exposure time and frequency of skin antisepsis of the operative field . In the present study, the antiseptic effect of a single use (single-application group) of 10% povidoneiodine solution for skin antisepsis was compared with its triple use (triple-application group) . The exposure time was 2 min for both groups . Moreover, the effects on blood levels of total iodine and thyroid-gland-related substances were evaluated . High antiseptic efficacy was obtained in both groups, indicating that our antiseptic method to disinfect the operative field is effective . Slightly better results were obtained from the triple-application group, although the difference was not statistically significant . Blood levels of total iodine and thyroid-gland-related substances remained within the normal range in all cases . However, in cases receiving a large amount of 10% povidone-iodine solution a transient elevation in blood total iodine was observed . Thus, the 10% povidone-iodine solution is considered to be safe and effective for skin antisepsis of the operative field when applied repeatedly in a small amount per dose with an exposure time of about 2 min.

Childs Nerv Syst, 1997 Oct, 13(10), 546 - 9
Immunoglobulin prophylaxis in shunt infections: a prospective randomized study; Ersahin Y et al.; Cerebrospinal fluid shunt infection is serious and one of the most frequent complications of shunt implantation . Age has been one of the most significant host factors for the development of shunt infections . A relative deficiency of the immune response against bacteria in infants could partly explain the higher infection rate in the very young patients . This prospective-randomized study was conducted in two groups: group A (immunoglobulin group) and group B (control group) . There were 30 patients in each group . The patients in group A received intravenous immunoglobulin (Sandoglobulin) at a dose of 1 g/kg in the night before surgery . Each patient was followed up to 6 months . No infection was seen in group A . In group B, infection rate per procedure were 5.1% (P = 0.494) and 6.6% (P = 0.492), respectively . Intravenous immunoglobulin prophylaxis in infants seems to reduce the shunt infections.

J Antibiot (Tokyo), 1997 Oct, 50(10), 860 - 5
New dihydro and tetrahydro derivatives of desmycosin . III . The opening of oxirane ring of 12,13-epoxydesmycosin; Naranda A et al.; Opening the oxirane ring of 12,13-epoxydesmycosin dimethylacetal (1) by catalytic hydrogenation gave the 10,11-dihydro-12,13-epoxy derivative (3) as the main product . Reductive oxirane cleavage was accomplished with dissolved metal (Zn) giving the 10,13-dihydro-13-hydroxy compound (6) . Mild acid hydrolysis of 6 gave expected 10,13-dihydro-13-hydroxydesmycosin (8), but hydrolysis of 3, under the same conditions, gave three tautomeric desepoxy products.

J Clin Periodontol, 1997 Nov, 24(11), 814 - 22
CD11b mRNA expression in neutrophils isolated from peripheral blood and gingival crevicular fluid; Watanabe K et al.; Adhesion molecule CD11b/CD18 expressed by neutrophils (PMNs) participates in cell migration and phagocytosis of C3bi derivatized bacteria . It is this phagocytic function that eliminates some of the known periodontal pathogens in periodontal pockets . In patients with advanced periodontitis, homotypic aggregation of crevicular fluid PMNs (CF-PMNs) may occur due to overexpression of CD11b/CD18 and this may lead to ineffective elimination of periodontal pathogens . We have previously shown that CF-PMNs isolated from the periodontal pockets overexpress CD11b compared to PB-PMNs . This study tested the hypotheses that (1) overexpression of surface CD11b correlates with expression of CD11b mRNA in CF-PMNs isolated from advanced periodontitis subjects, and (2) the intrinsic capacity of CD11b mRNA upregulation by PB-PMNs from periodontitis patients differs from that of control subjects . CF-PMNs and peripheral blood PMNs (PB-PMNs) were isolated from 13 subjects with healthy gingiva (control group) and 13 subjects with advanced periodontitis (patient group) . The surface expression of CD11b was determined by flow cytometry and CD11b mRNA was determined by extraction of mRNA and reverse transcription to cDNA followed by DNA amplification using primers to detect a segment of the cDNA which encodes CD11b . The results of this study confirm that the surface expression of CD11b on CF-PMNs is significantly higher in periodontitis subjects vs control subjects (p = 0.03), whereas surface CD11b expression on PB-PMNs does not differ significantly between groups (p = 0.06) . The level of surface CD11b expression on CF-PMNs did not correlate with the amount of mRNA present in CF-PMNs in either group (p = 0.056, 0.07 for control and periodontitis patients, respectively) . Most (9 of 13) individuals in the patient group expressed CD11b mRNA whereas very few control subjects (2 of 11) had CD11b mRNA in their CF-PMNs . This difference between groups was statistically significant (p = 0.004) . The capacity to upregulate CD11b mRNA upon stimulation with fMLP and/or GM-CSF was highly variable and there was no statistical difference between the 2 groups.

Mol Microbiol, 1997 Nov, 26(3), 581 - 96
Telomeres of the linear chromosomes of Lyme disease spirochaetes: nucleotide sequence and possible exchange with linear plasmid telomeres; Casjens S et al.; Bacteria of the spirochaete genus Borrelia have linear chromosomes about 950 kbp in size . We report here that these linear chromosomes have covalently closed hairpin structures at their termini that are similar but not identical to those reported for linear plasmids carried by these organisms . Nucleotide sequence analysis of the chromosomal telomeric regions indicates that unique, apparently functional genes lie within a few hundred bp of each of the telomeres, and that there is an imperfect 26 bp inverted repeat at the two telomeres . In addition, we characterize a major chromosomal length polymorphism within the right telomeric regions of various Borrelia isolates, and show that sequences similar to those near the right telomere are often found on linear plasmids in B . burgdorferi (sensu stricto) isolates from nature . Sequences similar to a number of other regions of the chromosome, including those near the left telomere, were not found on B . burgdorferi plasmids . These observations suggest that there has been historical exchange of genetic information between the linear plasmids and the right end of the linear chromosome.

Zoolog Sci, 1997 Aug, 14(4), 701 - 6
groE-homologous operon of Wolbachia, an intracellular symbiont of arthropods: a new approach for their phylogeny; Masui S et al.; Wolbachia, a member of rickettsia found in the cells of many arthropod species, are cytoplasmically inherited bacteria which interfere with host's sexuality and reproduction . Wolbachia strains have been phylogenetically divided into A and B groups based on the nucleotide sequences of their ftsZ genes . In an attempt to further define the phylogenetical relationship among these endosymbionts, we cloned and sequenced the entire length of the groE operon of a Wolbachia harbored by a cricket . The operon encoded two heat shock proteins, which represented the third and fourth proteins of any Wolbachia ever characterized . Also, 800 bp stretches of the groE operons of several other Wolbachia were sequenced, and a phylogenetic tree was constructed based on the results . The groE tree defined the relationship among A group Wolbachia strains that had not been successfully resolved by the ftsZ tree, and suggested unexpected horizontal transmission of these bacteria.

Pol J Pathol, 1997, 48(3), 159 - 61
Gastric fundic gland polyps (Elster's polyps) and Helicobacter pylori-induced gastritis; Stachura J et al.; In a series of 555 gastric polyps characteristic Elster's polyps were identified in 31 cases . Spiral bacteria (Helicobacter pylori) in these polyps were sporadic, much less frequent (9.7%) than in hyperplastic polyps (35%) in the present series and in relation to the bacteria frequency found in our randomly chosen gastric biopsy specimens (43%) . The present results indicate that Elster's polyps are not readily colonized by Helicobacter pylori and accordingly, they do not show the signs of active gastritis . The reasons for this are unknown . One of the mechanisms preventing from bacterial colonization may be a different from normal gastric mucosa and other polyps character of mucus produced by glandular neck cells, which was found in our series of gastric fundic gland polyps.

J Bacteriol, 1997 Dec, 179(24), 7816 - 26
bldA-dependent expression of the Streptomyces exfoliatus M11 lipase gene (lipA) is mediated by the product of a contiguous gene, lipR, encoding a putative transcriptional activator; Servin-Gonzalez L et al.; Extracellular lipase synthesis by Streptomyces lividans 66 carrying the cloned lipase gene (lipA) from Streptomyces exfoliatus M11 was found to be growth phase dependent, since lipase was secreted into the medium mainly during the stationary phase; S1 nuclease protection experiments revealed abundant lipA transcripts in RNA preparations obtained during the stationary phase but not in those obtained during exponential growth . Transcription from the lipA promoter was dependent on the presence of lipR, a contiguous downstream gene with a very high guanine-plus-cytosine content (80.2%) . The deduced lipR product consists of a protein of 934 amino acids that shows similarity to known transcriptional activators and has a strong helix-turn-helix motif at its C terminus; this motif is part of a domain homologous to DNA-binding domains of bacterial regulators of the UhpA/LuxR superfamily . The lipR sequence revealed the presence of a leucine residue, encoded by the rare TTA codon, which caused bldA dependence of lipA transcription in Streptomyces coelicolor A3(2); replacement of the TTA codon by the alternate CTC leucine codon alleviated bidA dependence but not the apparent growth phase-dependent regulation of lipA transcription . When lipR expression was induced in a controlled fashion during the exponential growth phase, by placing it under the inducible tipA promoter, lipase synthesis was shifted to the exponential growth phase, indicating that the timing of lipR expression, and not its bldA dependence, is the main cause for stationary-phase transcription of lipA.

J Bacteriol, 1997 Dec, 179(24), 7748 - 58
Regulation of expression of the pilA gene in Myxococcus xanthus; Wu SS et al.; Type IV pili are required for social gliding motility in Myxococcus xanthus . In this work, the expression of pilin (the pilA gene product) during vegetative growth and fruiting-body development was examined . A polyclonal antibody against the pilA gene product (prepilin) was prepared, along with a pilA-lacZ fusion, and was used to assay expression of pilA in M . xanthus in different mutant backgrounds . pilA expression required the response regulator pilR but was negatively regulated by the putative sensor kinase pilS . pilA expression did not require pilB, pilC, or pilT . pilA was also autoregulated; a mutation which altered an invariant glutamate five residues from the presumed prepilin processing site eliminated this autoregulation, as did a deletion of the pilA gene . Primer extension and S1 nuclease analysis identified a sigma54 promoter upstream of pilA, consistent with the homology of pilR to the NtrC family of response regulators . Expression of pilA was found to be developmentally regulated; however, the timing of this expression pattern was not entirely dependent on pilS or pilR . Finally, pilA expression was induced by high nutrient concentrations, an effect that was also not dependent on pilS or pilR.

J Leukoc Biol, 1997 Dec, 62(6), 901 - 10
Agonist-specific tyrosine phosphorylation of Cbl in human neutrophils; Naccache PH et al.; The effects of soluble and particulate agonists on the tyrosine phosphorylation levels of the proto-oncogene Cbl in human neutrophils were examined . Experimental conditions allowing the maintenance of Cbl as well as of its tyrosine phosphorylation status were first established . Their use allowed us to observe that Cbl was tyrosine phosphorylated in response to some (FcgammaRII ligation, opsonized bacteria and zymosan, granulocyte-macrophage colony-stimulating factor, monosodium urate, and calcium pyrophosphate microcrystals), but not all (fMet-Leu-Phe, interleukin-8) neutrophil agonists . Cbl was also shown to account for a varying proportion of the 120-kDa phosphoprotein(s) observed in response to the above stimuli . These data establish that Cbl is present in human neutrophils and that its level of tyrosine phosphorylation is modulated by some of these cells' agonists, and in particular by phagocytic particles . Furthermore, the signaling pathways activated by chemotactic factors and the other neutrophil stimuli tested in this investigation diverge at or downstream from the tyrosine phosphorylation of Cbl.

Am J Gastroenterol, 1997 Dec, 92(12), 2220 - 4
Prevalence and pattern of Helicobacter pylori gastritis in the gastric cardia; Hackelsberger A et al.; OBJECTIVES: Helicobacter pylori has a predilection for antral colonization . Local acid production is the major determinant of colonization . Because production is low in the antrum and cardia, H . pylori should also colonize the cardia . We therefore investigated the histologic pattern of gastritis and the prevalence of H . pylori in the cardia compared with the antrum and corpus . METHODS: From 135 H . pylori-infected patients with gastritis, ulcer disease, or reflux esophagitis, biopsies were obtained from the antrum, corpus, and cardia . The prevalence, topography, and histologic parameters of gastritis were examined . RESULTS: All 135 patients had active antral H . pylori gastritis: in the cardia, 132 of these patients (97.7%) showed active gastritis, and 124 patients (91.9%) had H . pylori visible on staining . Gastritis of the cardia in most patients resembled antral gastritis, but the density of bacteria and the inflammatory responses were less marked . The most striking finding in the cardia of patients with gastroesophageal reflux was a lower density of bacteria compared with antrum and corpus . Intestinal metaplasia was found in 32 patients in antral mucosa (23.7%) versus 28 patients in the cardia (20.7%), versus 11 patients in the corpus (8.1%), and was multifocal in 17 patients (12.6%) . CONCLUSIONS: H . pylori gastritis commonly involves the cardia . The histologic density of the bacteria and inflammatory responses are lower than in the antrum . Intestinal metaplasia in the cardia is a common finding in H . pylori gastritis . The cause of the lower bacterial density in the cardia of patients with reflux esophagitis needs further investigation.

J Clin Microbiol, 1997 Dec, 35(12), 3338 - 9
Peritonitis associated with a CDC group EO-3 organism; Daley D et al.; A 63-year-old female with chronic renal failure on continuous ambulatory peritoneal dialysis developed chronic peritonitis . A CDC group EO-3 organism was isolated from the peritoneal dialysis fluid on five occasions over a period of 4 months . This is the first reported isolation of this organism in which it is associated with a patient on continuous ambulatory peritoneal dialysis.

Helicobacter, 1996 Sep, 1(3), 183 - 6
Egg passage of rodshaped and coccoid forms of Helicobacter pylori: preliminary studies; Enroth H et al.; BACKGROUND: We used egg passage of bacteria stored in water to evaluate the culturability of the coccoid form of Helicobacter pylori, as a complement to the results obtained from various animal models . Egg passage was performed, as it is a simple, rapid, and well-characterized old method by which to culture and evaluate culturability of bacteria compared to experiments in animal models . Egg passage has been used in such experiments since 1938 for isolation and growth of, for example, Rickettsiae sp . and Chlamydia sp . MATERIALS AND METHODS: The rod-shaped form of H . pylori was produced by plate cultures for 4 and 7 days . The coccoid form of H . pylori was produced by culture on agar plates for 10 days, followed by storage in water . These preparations then were inoculated into the yolk sac of differently aged fertilized eggs . RESULTS: Positive culture was obtained from 14 of 17 eggs (82%) inoculated with rod-shaped H . pylori compared to 0 of 22 eggs (0%) inoculated with the coccoid form . CONCLUSION: Culturability of H . pylori is reduced when it converts into the coccoid form produced by starvation and age followed by storage in water for several weeks at room temperature . Egg passage did not raise the culturability of the coccoid form of H . pylori . Our study demonstrates some clear differences between fresh rods and stored cocci forms of H . pylori in terms of culturability when passed through eggs.

Helicobacter, 1996 Jun, 1(2), 98 - 106
Mixed infection with cagA-positive and cagA-negative strains of Helicobacter pylori; Fantry GT et al.; BACKGROUND: Helicobacter pylori infection has been implicated strongly in the pathogenesis of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma, but the reasons for these widely different clinical outcomes are unknown . The aim of this study was to determine whether these differences could be due in part to mixed infection in the same individual, with bacteria having differences in pathogenic factors associated with ulcers . MATERIALS AND METHODS: The cagA gene of H . pylori was used to test for mixed infection because it is present in only some strains, and its presence has been associated with ulcers . Polymerase chain reaction (PCR) assays for the cagA gene were applied to H . pylori culture isolates and endoscopic gastric aspirates . Individual bacterial clones were tested for genetic similarity by random primer amplification and restriction endonuclease digestion of urease gene PCR products . RESULTS: The majority of H . pylori-positive patients had strongly cagA-positive culture isolates and endoscopic samples (62.5% and 69.6%, respectively) . However, many of these patients had evidence of mixed infection with cagA negative and cagA positive strains in cultures isolates and endoscopic samples (25% and 17.4%, respectively) . Mixed infection was found to be due to genetically unrelated strains in two patients in whom genetic analysis was performed . CONCLUSION: Mixed infection with differences in substrain pathogenic factors might occur in H . pylori infection and might contribute to differences in clinical outcome.

Biochemistry, 1997 Dec 2, 36(48), 14690 - 6
Proton nuclear magnetic resonance investigation of the {2Fe-2S}(1-)-containing "Rieske-type" protein from Xanthobacter strain Py2; Holz RC et al.; Proton NMR spectra of the Rieske-type ferredoxin from Xanthobacter strain Py2 were recorded in both H2O and D2O buffered solutions at pH 7.2 . Several well-resolved hyperfine-shifted 1H NMR signals were observed in the 90 to -20 ppm chemical shift range . Comparison of spectra recorded in H2O and D2O buffered solutions indicated that the signals at -11.4 (L) and -15.5 (M) ppm were solvent-exchangeable and thus were assigned to the two histidine N epsilon 2H protons . The remaining observed signals were assigned based upon chemical shift, T1 values, and one-dimensional nuclear Overhauser effect (nOe) saturation transfer experiments to either C beta H or C alpha H protons of cluster cysteinyl or histidine ligands . Upon oxidation of the {2Fe-2S} cluster, only two broad resonances were observed, indicating that the two Fe(III) ions are strongly antiferromagnetically coupled . In addition, the temperature dependence of each observed hyperfine-shifted signal in the reduced state was determined, providing information about the magnetic properties of the {2Fe-2S}1- cluster . Fits of the temperature data observed for each resonance to equations describing the hyperfine shift with their Boltzmann weighting factors provided a delta EL value of 185 +/- 26 cm-1 which, in turn, gives -2J as 124 cm-1 . These data indicate that the two iron centers in the reduced {2Fe-2S} Rieske-type center are moderately antiferromagnetically coupled . The combination of these data with the available spectroscopic and crystallographic results for Rieske-type proteins has provided new insights into the role of the Rieske-type protein from Xanthobacter strain Py2 in alkene oxidation.

Hepatology, 1997 Dec, 26(6), 1607 - 15
Hepatic expression of the woodchuck hepatitis virus X-antigen during acute and chronic infection and detection of a woodchuck hepatitis virus X-antigen antibody response; Jacob JR et al.; The expression and localization of the woodchuck hepatitis virus X-antigen (WHxAg) was examined and compared with other markers of a woodchuck hepatitis virus (WHV) infection using rabbit antisera generated against recombinant WHxAg produced in bacteria . Cellular fractionation studies showed that WHxAg was localized to the soluble and cytoskeletal fractions of the cell when assayed by immunoprecipitation of {35S}-met-cys labeled extracts derived from primary cultures of acute WHV-infected hepatocytes . Immunohistochemical examination of liver from chronic WHV-infected animals showed WHV core antigen (WHcAg) and WHxAg expression in non-neoplastic tissue . The WHxAg was found localized to the cytoplasm of infected cells, similar to WHcAg . WHxAg expression was diminished in the foci of altered hepatocytes and in hepatocellular adenomas but was found in only 1 of 11 hepatocellular carcinomas (HCC) . Hepatic biopsies from woodchucks experimentally inoculated with WHV were examined during the acute phase of infection and during convalescence for WHcAg and WHxAg expression by immunohistochemistry . Concurrent expression of WHcAg and WHxAg was observed during the viremic phase of infection . The two antigens exhibited similar localization to the cell cytoplasm, similar distribution within the liver lobule, and similar patterns of clearance during convalescence . An immune response to WHxAg was documented in some woodchucks following acute WHV infection . These studies further define the woodchuck model of HBV infection and should allow for the investigation of the role of hepadnaviral X-antigen expression in the pathogenesis of chronic hepatitis and HCC.

Crit Rev Biotechnol, 1997, 17(4), 327 - 61
Alginate production by Azotobacter vinelandii; Clementi F; Although all commercial alginates are today of algal origin, there is interest in the production of alginate-like polymers from bacteria . The species Azotobacter vinelandii seems to be the best candidate for the industrial production of alginate molecules characterized by a chemical composition, molecular mass and molecular mass distribution suited to a well defined application, especially required in the biotechnological, biomedical and pharmaceutical fields . The production of alginate by A . vinelandii has been to date widely investigated both in batch (mainly in the shaken flask scale) and in continuous cultures . This article summarizes current knowledge on the structure and properties of alginates and their applications and presents an overview of up-dated research on the physiology, genetics and kinetics of the production of alginate by Azotobacter vinelandii and its rheology, including the results of our recent studies.

Kaibogaku Zasshi, 1997 Oct, 72(5), 407 - 23
{One hundred years of sinusoidal cells in the liver}; Wake K; Kupffer (1898) reported that the stellate cells were phagocytic endothelial cells, retracting his earlier view that these cells were perivascular cells . His new concept stimulated studies on the vital staining and the RES theory, while it ensued several controversies in liver histology . The original stellate cells were rediscovered in 1971, and were proved to be identical with several perisinusoidal cells reported previously . For this cell the term hepatic stellate cell has recently been adopted as the standardized name . The space of Disse is newly defined as the space between the endothelial cell-stellate cell complex and the parenchymal cells . The stellate cells display vitamin A-storage, collagen synthesis and may contract to regulate the sinusoidal blood flow and the fluid-exchange between the sinusoidal lumen and the space of Disse . The sinusoidal endothelial cells uptake injected lithium carmine and macromolecules by coated vesicles . Kupffer cells clear endotoxin, bacteria and apoptotic neutrophils and release various cytokines . The pit cells are the liver-associated NK cells and are activated by the administration of biological response modifiers, preventing tumor metastasis . Extrathymic pathways of T cell differentiation exist in the hepatic sinusoid . The dendritic cells differentiate in the sinusoid and translocate to the Glisson's sheath . Intralobular heterogeneity of sinusoidal cells have been observed . The sinusoidal cells communicate each other with autocrine and paracrine mechanisms to regulate various functions of the liver.

Gastroenterology, 1997 Dec, 113(6 Suppl), S43 - 9; discussion S50
How does Helicobacter pylori cause mucosal damage? Its effect on acid and gastrin physiology; Calam J et al.; Helicobacter pylori infection increases gastric acid secretion in patients with duodenal ulcers but diminishes acid output in patients with gastric cancer and their relatives . Investigation of the basic mechanisms may show how H . pylori causes different diseases in different persons . Infection of the gastric antrum increases gastrin release . Certain cytokines released in H . pylori gastritis, such as tumor necrosis factor alpha and specific products of H . pylori, such as ammonia, release gastrin from G cells and might be responsible . The infection also diminishes mucosal expression of somatostatin . Exposure of canine D cells to tumor necrosis factor alpha in vitro reproduces this effect . These changes in gastrin and somatostatin increase acid secretion and lead to duodenal ulceration . But the acid response depends on the state of the gastric corpus mucosa . The net effect of corpus gastritis is to decrease acid secretion . Specific products of H . pylori inhibit parietal cells . Also, interleukin 1 beta, which is overexpressed in H . pylori gastritis, inhibits both parietal cells and histamine release from enterochromaffin-like cells . H . pylori also promotes gastric atrophy, leading to loss of parietal cells . Factors such as a high-salt diet and a lack of dietary antioxidants, which also increase corpus gastritis and atrophy, may protect against duodenal ulcers by decreasing acid output . However, the resulting increase of intragastric pH may predispose to gastric cancer by allowing other bacteria to persist and produce carcinogens in the stomach.

Gastroenterology, 1997 Dec, 113(6), 1836 - 47
Regulation of gastric epithelial cell growth by Helicobacter pylori: offdence for a major role of apoptosis; Wagner S et al.; BACKGROUND & AIMS: Helicobacter pylori may affect the normal balance between gastric epithelial cell proliferation and epithelial cell death, thus interfering with the maintenance of gastric mucosal integrity . The aim of this study was to investigate the effect of H . pylori on cell growth, DNA synthesis, induction of apoptosis, and viability of human gastric epithelial cells in vitro . METHODS: H . pylori was incubated with a differentiated human gastric cancer cell line for up to 72 hours, and the effects on cell numbers (cell counts and WST-1 assay), DNA synthesis (5-bromo-2'-deoxyuridine assay and {3H}thymidine incorporation), and DNA fragmentation (DNA fluorochrome staining, transmission electron microscopy, and histone enzyme-linked immunosorbent assay) were assessed . RESULTS: Incubation of gastric epithelial cells with H . pylori led to a time- and concentration-dependent reduction of epithelial cell growth and a concomitant induction of DNA fragmentation . At high bacteria-cell ratios (> 100), inhibition of cell growth was associated with a reduction in DNA synthesis . Treatment of gastric cells with tumor necrosis factor alpha, a receptor-activating CD95/APO-1/Fas antibody, and interferon gamma markedly potentiated H . pylori-induced DNA fragmentation . CONCLUSIONS: H . pylori affects gastric epithelial cell growth by direct induction of apoptosis and inhibition of DNA synthesis and indirectly by sensitization of epithelial cells for apoptosis induced by proinflammatory stimuli.

Infect Immun, 1997 Dec, 65(12), 5330 - 3
The role of Legionella pneumophila-infected Hartmannella vermiformis as an infectious particle in a murine model of Legionnaire's disease; Brieland JK et al.; Legionella pneumophila is a bacterial parasite of many species of freshwater protozoa and occasionally an intracellular pathogen of humans . While protozoa are known to play a key role in the persistence of L . pneumophila in the environment, there has been limited research addressing the potential role of L . pneumophila-infected protozoa in the pathogenesis of human infection . In this report, the potential role of an L . pneumophila-infected amoeba as an infectious particle in replicative L . pneumophila lung infection was investigated in vivo with the amoeba Hartmannella vermiformis, a natural reservoir of L . pneumophila in the environment . L . pneumophila-infected H . vermiformis organisms were prepared by coculture of the amoebae and virulent L . pneumophila cells in vitro . A/J mice, which are susceptible to replicative L . pneumophila lung infection, were subsequently inoculated intratracheally with L . pneumophila-infected H . vermiformis organisms (10(6) amoebae containing 10(5) bacteria), and intrapulmonary growth of the bacteria was assessed . A/J mice inoculated intratracheally with L . pneumophila-infected H . vermiformis organisms developed replicative L . pneumophila lung infections . Furthermore, L . pneumophila-infected H . vermiformis organisms were more pathogenic than an equivalent number of bacteria or a coinoculum of L . pneumophila cells and uninfected amoebae . These results demonstrate that L . pneumophila-infected amoebae are infectious particles in replicative L . pneumophila infections in vivo and support the hypothesis that inhaled protozoa may serve as cofactors in the pathogenesis of pulmonary disease induced by inhaled respiratory pathogens.

Infect Immun, 1997 Dec, 65(12), 5295 - 300
A highly adherent phenotype associated with virulent Bvg+-phase swine isolates of Bordetella bronchiseptica grown under modulating conditions; Register KB et al.; The ability of Bvg(-)-phase and Bvg(+)-phase Bordetella bronchiseptica swine isolates, grown under modulating or nonmodulating conditions, to adhere to swine ciliated nasal epithelial cells was determined . When virulent strains were cultivated at 37 degrees C in the Bvg+ phase, numerous adherent bacteria (approximately eight per cell, depending on the strain used) were observed . However, when such strains were grown under modulating conditions (23 degrees C), a significant increase in the level of attachment was seen, suggesting that B . bronchiseptica produces a Bvg-repressed adhesin under these conditions . bvg mutant strains, including an isogenic bvgS mutant, adhered minimally . Western blots indicated that two putative B . bronchiseptica adhesins, filamentous hemagglutinin and pertactin, were not detectable in cultures displaying the highly adherent phenotype . Several proteins apparent in Western blots obtained by using bacterial extracts enriched in outer membrane proteins derived from B . bronchiseptica grown at 23 degrees C were not present in similar extracts prepared from an isogenic bvgS mutant grown at 23 degrees C or from the parent strain grown at 37 degrees C . Adherence of bacteria cultivated at 23 degrees C was almost completely abolished by pretreatment of organisms at 60 degrees C; adherence was reduced by 57% when bacteria were pretreated with pronase E . Temperature shift experiments revealed that the heightened level of adhesion that occurs following growth at 23 degrees C was maintained for up to 18 h when bacteria were subsequently incubated at 37 degrees C . We propose that a Bvg-repressed adhesin, expressed only by modulated bvg+ strains of B . bronchiseptica, may play a key role in the initial colonization of naturally infected swine.

Infect Immun, 1997 Dec, 65(12), 5067 - 73
Cryptosporidium parvum infection of human intestinal epithelial cells induces the polarized secretion of C-X-C chemokines; Laurent F et al.; Cryptosporidium parvum infects intestinal epithelial cells and does not invade deeper layers of the intestinal mucosa . Nonetheless, an inflammatory cell infiltrate that consists of neutrophils and mononuclear cells is often present in the lamina propria, which underlies the epithelium . This study investigated the host epithelial cell response to C . parvum by assessing in vitro and in vivo the expression and production of proinflammatory cytokines by intestinal epithelial cells after infection . The human colon epithelial cell lines HCT-8 and Caco-2 and human intestinal xenografts in SCID mice were infected with C . parvum . The expression and secretion of the C-X-C chemokines interleukin-8 (IL-8) and GROalpha were determined by reverse transcription-PCR analysis and enzyme-linked immunosorbent assay . Our results demonstrate that upregulated expression and secretion of IL-8 and GROalpha after C . parvum infection of intestinal epithelial cells first occurred 16 to 24 h after infection and increased over the ensuing 1 to 2 days . The kinetics of C-X-C chemokine production by C . parvum-infected epithelial cells contrast markedly with the rapid but transient expression of C-X-C chemokines by epithelial cells infected with invasive enteric bacteria . C-X-C chemokine secretion in C . parvum-infected epithelial cells occurred predominantly from the basolateral surface in polarized monolayers of Caco-2 cells grown in Transwell cultures, whereas cell lysis occurred at the apical surface . The basolateral secretion of IL-8 and GROalpha from C . parvum-infected epithelial cells suggests that C-X-C chemokines produced by those cells contribute to the mucosal inflammatory cell infiltrate in the underlying intestinal mucosa.

Infect Immun, 1997 Dec, 65(12), 4904 - 8
Role of gamma interferon in natural clearance of Bordetella pertussis infection; Barbic J et al.; Using a mouse model of Bordetella pertussis infection, we have analyzed the role of gamma interferon (IFN-gamma) in bacterial clearance from the respiratory tract . Adult BALB/c mice began to clear a respiratory infection within 3 weeks postinfection, with complete resolution of infection 6 to 8 weeks postinfection . In contrast, neither adult SCID mice (which lack mature B and T lymphocytes) nor adult nude mice (which lack mature T lymphocytes) controlled B . pertussis infection, and both strains died within 3 to 5 weeks postinfection . Short-term T-cell lines generated from the draining lymph nodes of the lungs of infected BALB/c mice were found to be CD4+ and produced IFN-gamma but no detectable interleukin-4 . Analyses of IFN-gamma mRNA induction in the lungs of mice following B . pertussis infection showed that in both BALB/c and C57BL/6 mice, IFN-gamma mRNA levels increased sharply by 1 week postinfection and then subsequently declined . Further exploration of a potential role for IFN-gamma demonstrated that infection of adult BALB/c mice depleted of IFN-gamma in vivo with anti-IFN-gamma monoclonal antibodies resulted in greater numbers of bacteria recovered from the lungs than in infected, control BALB/c mice, although IFN-gamma-depleted mice could subsequently clear the infection . Infection of mice which have a disrupted IFN-gamma gene resulted in bacterial clearance with a time course similar to those seen with IFN-gamma-depleted mice . These results indicate that IFN-gamma plays a role in controlling B . pertussis infection.

Vet Rec, 1997 Nov 1, 141(18), 469 - 72
Immunotoxicological effects on piglets of feeding sows diets containing aflatoxins; Silvotti L et al.; Three groups of four Large White sows were fed diets containing either 800 ppb purified aflatoxin B1 (group 1), 800 ppb purified aflatoxin G1 (group 2) or 400 ppb B1 and 400 ppb G1 (group 3) throughout gestation and lactation . A control group of four sows was fed a diet free of aflatoxins . Aflatoxins B1 and M1 were found in milk samples taken five and 25 days after parturition from the sows of group 1, aflatoxin G1 was present in the milk of the sows of group 2 and all three aflatoxins were present in samples from the sows of group 3 . The concentration of aflatoxin in the milk was about 1000-fold lower than that in the feed, but increased over the 25 days after parturition . The piglet suckling on a central teat was selected from each sow, given sow milk until the fourth day of age, and was then free to eat prepared feed while suckling . At the 25th day of age the selected piglets were removed from the sow and sacrificed . Blood samples were collected from each piglet and cellular populations were separated for immunological measurements: an in vitro lymphocyte proliferation test, and tests to derive the phagocytic activity, phagocytic index and superoxide anion production of monocyte-derived macrophages were carried out along with studies on the motility, differential chemotaxis and chemotactic index of circulating granulocytes . The lymphoproliferative response to mitogens was reduced and monocyte-derived macrophages failed to efficiently produce superoxide anions after oxidative burst stimulation in vitro, while their ability to phagocytose red blood cells was not compromised . Granulocytic cells showed a reduction of chemotactic response in vitro to chemoattractant bacteria factor and casein.

Crit Rev Oral Biol Med, 1997, 8(4), 437 - 60
Tobacco and smoking: environmental factors that modify the host response (immune system) and have an impact on periodontal health; Barbour SE et al.; This review summarizes the current data on the effects of smoking and tobacco on the immune system and its potential impact on periodontal health . Smokers are 2.5-6 times more likely to develop periodontal disease than non-smokers, and there is evidence for a direct correlation between the number of cigarettes smoked and the risk of developing disease . Tobacco users also tend to exhibit increased severity of periodontal disease . Direct correlations between tobacco use and increased attachment loss and pocket depth and reduced bone crest height have been reported . Although the correlation between tobacco use and periodontal disease is quite strong, the role of tobacco in the pathogenesis of periodontal disease is uncertain . Recent studies indicate that one potential mechanism is that tobacco use exacerbates periodontal disease because it alters the immune response to periodontal pathogens . Indeed, smokers exhibit increased numbers of peripheral blood mononuclear phagocytes which appear to be functionally compromised . Inadequate phagocyte activity could reduce the clearance of pathogens from the oral cavity and thereby facilitate the development of periodontal disease . Tobacco-exposed B- and T-lymphocytes exhibit reduced proliferative capacities which could limit the production of protective immunoglobulins against oral pathogens . The risk factors for periodontal disease can be broadly classified as genetic, environmental, host-response factors, and host-related factors such as age . Tobacco, an environmental factor, undermines the host response and may facilitate the development and progression of periodontal disease . This review highlights the inter-relatedness of two of the risk factors associated with periodontal disease.

J Natl Cancer Inst, 1997 Nov 19, 89(22), 1692 - 7
Effects of acetaldehyde on cell regeneration and differentiation of the upper gastrointestinal tract mucosa; Homann N et al.; BACKGROUND: The tumor-promoting effect of ethanol on cancer of the upper respiratory-digestive tract is not well understood . Although ethanol itself is not carcinogenic, the first product of ethanol metabolism-acetaldehyde is . Acetaldehyde can be produced from ethanol by oral bacteria, and high concentrations have been observed in human saliva after ethanol consumption . The purpose of this study was to investigate whether acetaldehyde administered orally to rats induces altered differentiation and proliferation in the animals' upper gastrointestinal tracts . METHODS: Twenty Wistar rats were given either water containing acetaldehyde at a concentration of 120 mM or tap water to drink for 8 months . Tissue specimens were then taken from the tongue, epiglottis, and forestomach of each animal and immunohistochemically stained for markers of cellular proliferation (Ki67 nuclear antigen) or differentiation (cytokeratins 1, 4, 10, 11, 14, and 19) . The mean epithelial thickness of each sample was measured via light microscopy, using an eyepiece containing grid lines . Differences between the control and acetaldehyde-treated groups were analyzed by use of the unpaired Student's t test . All reported P values are two-sided . RESULTS: Although no tumors were observed, staining for cytokeratins 4 and 14 revealed an enlarged basal layer of squamous epithelia in the rats receiving acetaldehyde . In these animals, cell proliferation was significantly greater than that observed in the control animals for samples from the tongue (P<.0001), epiglottis (P<.001), and forestomach (P<.0001) . In addition, the epithelia from acetaldehyde-treated rats were significantly thicker than in epithelia from control animals (P<.05 for all three sites) . CONCLUSIONS: Acetaldehyde, administered orally to rats, can cause hyperplastic and hyperproliferative changes in epithelia of the upper gastrointestinal tract . This finding suggests that microbially produced acetaldehyde in saliva may explain the tumor-promoting effect of ethanol on these epithelia.

Kyobu Geka, 1997 Nov, 50(12), 1055 - 8
{A case of huge abscess extended from anterior neck to left lung and lateral chest wall}; Ikeya T et al.; 62-year-old woman admitted our hospital with pain of left upper extremity from the left chest and dysphasia . Chest X-ray showed the huge mass shadow in the left lung field . Diabetes mellitus and inflammatory reaction such as high fervor, leukocytosis, CRP and ESR accentuation were recognized . Conservative therapy was done at first, but mass shadow on X-ray increased, and swelling appeared from the neck to the left lateral chest wall . And the same site appeared like subcutaneous emphysema . Computed Tomography showed mass shadow which was enlarged and spread in lung parenchyma and left chest wall with bubble image . Incision and open drainage was performed for the left chest wall but origin bacteria was detected in neither anaerobic nor aerobic culture of pus . Inflammation and mass shadow of left upper lung field have decreased gradually . The patient discharged without bronchoalveolar fistula . Abscess extending from the neck or chest wall with diabetes mellitus is very rare.

J Lipid Res, 1997 Oct, 38(10), 2003 - 11
Interactions between cationic liposomes and an antigenic protein: the physical chemistry of the immunoadjuvant action; Tsuruta LR et al.; The 18 kDa antigenic protein from Mycobacterium leprae (P) or its N-acyl derivative (AP) was incorporated in dioctadecyldimethylammonium bromide (DODAB) liposomes in water or in phosphate-buffered saline (PBS) . In water, 100% P incorporation in liposomes contrasts with 65% in PBS . There is 75-80% AP incorporation to liposomes in water against 55-65% in PBS, showing that attachment of hydrophobic residues to the protein, instead of increasing, further decreases incorporation to the liposomes . From protein adsorption on latex, P affinity is larger than AP affinity for the latex surface whereas limiting adsorption for AP is much larger than that obtained for P, possibly due to AP aggregation in solution . P-induced rupture of liposomes containing {14C}sucrose was evaluated from dialysis of protein/liposomes mixtures . In water, P incorporation to the liposomes causes leakage of radioactive contents contrasting with the absence of leakage for P incorporation in PBS . Immunization tests for delayed type hypersensitivity indicate a enhancement of cell-mediated immunological response towards P/DODAB complexes that is not obtained for the isolated protein . Absence of leakage for P in PBS is associated with a P "lying-over" on the liposome and optimization of protein presentation to the immunological system.

Alcohol Alcohol, 1997 Sep-Oct, 32(5), 543 - 9
The role of gastrointestinal factors in alcohol metabolism; Seitz HK et al.; Although the liver is the major organ responsible for ethanol metabolism, such metabolism also occurs in the gastrointestinal (GI) tract . However, compared to the liver, GI metabolism of ethanol is quantitatively much lower . Various enzyme systems have been characterized in GI mucosal cells including various isozymes of alcohol dehydrogenase (ADH), cytochrome P450 2E1 (CYP 2E1) and catalase . Gastric ADH activity is one factor by which first pass metabolism (FPM) is influenced and its activity is modulated by genetics, gender, age, drugs and gastric morphology . Another important factor in FPM of ethanol is the speed of gastric emptying . In addition to mucosal ethanol metabolism, ethanol can also be oxidized by many bacterial species in the upper GI tract including oropharynx and stomach as well as in the large intestine . GI metabolism of ethanol may influence systemic bioavailability of ethanol and may lead to local toxicity most likely mediated by acetaldehyde . Such toxicity could be of importance in ethanol-associated carcinogenesis.

Biophys J, 1997 Nov, 73(5), 2527 - 33
Penetration of the insect defensin A into phospholipid monolayers and formation of defensin A-lipid complexes; Maget-Dana R et al.; Defensin A is an inducible cationic protein secreted in the hemolymph of fleshfly Phormia terranovae larvae in response to bacterial or septic injuries . Defensin A is known to permeabilize the bacteria cell membranes by forming voltage-dependent channels . The penetration of this small protein into lipid monolayers was studied as a function of the polar head and acyl chain length of phospholipids . The extent of penetration by defensin A is higher in monolayers made of anionic phospholipids than in monolayers made of zwitterionic phospholipids (phosphatidylcholines), because of electrostatic interactions . From the analysis of the compression isotherm parameters of mixed defensin A/phospholipid monolayers, it appears that defensin A interacts with phospholipid by forming 1:4 complexes . These complexes are not miscible in the lipid phase and induce microheterogeneity in the lipid membrane . These clusters might be related to the ion-channel structures responsible for the biological activity of defensin A.

Eur J Biochem, 1997 Oct 15, 249(2), 497 - 504
Transport of CtpA protein from the cyanobacterium Synechocystis 6803 across the thylakoid membrane in chloroplasts; Karnauchov I et al.; The CtpA protein in the cyanobacterium Synechocystis 6803 is a C-terminal processing protease that is essential for the assembly of the manganese cluster of the photosystem II complex . When fused to different chloroplast-targeting transit peptides, CtpA can be imported into isolated spinach chloroplasts and is subsequently translocated into the thylakoid lumen . Thylakoid transport is mediated by the cyanobacterial signal peptide which demonstrates that the protein transport machinery in thylakoid membranes is functionally conserved between chloroplasts and cyanobacteria . Transport of CtpA across spinach thylakoid membranes is affected by both nigericin and sodium azide indicating that the SecA protein and a transthylakoidal proton gradient are involved in this process . Saturation of the Sec-dependent thylakoid transport route by high concentrations of the precursor of the 33-kDa subunit of the oxygen-evolving system leads to a strongly reduced rate of thylakoid translocation of CtpA which demonstrates transport by the Sec pathway . However, thylakoid transport of CtpA is affected also by excess amounts of the 23-kDa subunit of the oxygen-evolving system, though to a lesser extent . This suggests that the cyanobacterial protein is capable of also interacing with components of the deltapH-dependent route and that transport of a protein across the thylakoid membrane may not always be restricted to a single pathway.

Gene, 1997 Oct 1, 198(1-2), 351 - 7
Characterization of the human MANB gene encoding lysosomal alpha-D-mannosidase; Wakamatsu N et al.; Genomic clones of human MANB gene encoding the lysosomal enzyme, alpha-mannosidase, have been isolated, sequenced and analyzed . The human MANB gene spans approximately 22 kb and consists of 24 exons . The 5' flanking region of the gene shows a high G+C content and has two Sp1 and three AP-2 sites . Promoter analysis using deletion constructs of the 5' flanking region fused to the bacterial CAT gene showed that 150 bp of 5' sequence could drive the expression of MANB in COS 7 cells . Determination of the sequence of the 5' end of the alpha-mannosidase mRNA by 5' RACE protocol showed that transcription is initiated from a cluster of sites centered -28 and -20 bp from the first in-frame ATG . These data demonstrate that, like other lysosomal enzyme genes such as those for beta-glucuronidase or beta-hexosaminidase, the human MANB gene is controlled by a short 5' flanking sequence located near the initiation codon.

Am J Obstet Gynecol, 1997 Oct, 177(4), 825 - 30
Amniotic fluid cytokines (interleukin-6, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-8) and the risk for the development of bronchopulmonary dysplasia; Yoon BH et al.; OBJECTIVE: Our purpose was to test the hypothesis that neonates who develop bronchopulmonary dysplasia have higher amniotic fluid concentrations of proinflammatory cytokines than those who do not develop bronchopulmonary dysplasia . STUDY DESIGN: The relationship between amniotic fluid concentrations of interleukin-6, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-8 and the occurrence of bronchopulmonary dysplasia in the neonate was examined in 69 patients who were delivered of preterm neonates (< or = 33 weeks) within 5 days of amniocentesis . Cytokines were measured by specific immunoassays . RESULTS: Bronchopulmonary dysplasia was diagnosed in 19% (13/69) of newborns . Median amniotic fluid concentrations of interleukin-6, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-8 concentrations were significantly higher in mothers whose infants had bronchopulmonary dysplasia than in mothers whose infants did not have bronchopulmonary dysplasia (p < 0.05 for each) . Neonates who had bronchopulmonary dysplasia were delivered at earlier gestational ages and had lower birth weights than those without bronchopulmonary dysplasia . The differences in median amniotic fluid interleukin-6, interleukin-1 beta, and interleukin-8 between these two groups remained significant after we adjusted for the effect of gestational age at birth (p < 0.05 for each) . CONCLUSIONS: (1) Antenatal exposure to proinflammatory cytokines is a risk factor for the development of bronchopulmonary dysplasia; (2) the injury responsible for bronchopulmonary dysplasia in a subset of neonates may begin before birth.

Zhonghua Hu Li Za Zhi, 1997 Feb, 32(2), 72 - 4
{The observation on the disinfecting efficiency of the disinfectant 93}; Fan FY et al.; Disinfectant 93 is a colorless and transparent liquid . It contains surfactant and hand-protective . Its major component is Di(octyl amino-ethyl) glycine hydrochloride . 99.8% natural bacteria could be removed from the medical staff's hands by using the disinfectant 93 to scrub for 1 min twice . According to the standard of the Ministry of Public Health, it is allowed that the amount of bacteria on the hands is less than equal to 10cfu/cm2 under the condition of class III, and less than equal to 5cfu/cm2 under the condition of class I {symbol: see text} II, in which the qualification rate reached to 100% and 98%, respectively . The average elimination rate of natural bacteria reached to 99.5% and 99.3%, when the hands of surgical operators were disinfected with the disinfectant 93 after scrubbing and brushing with soap . The results showed that disinfecting efficiency of the disinfectant 93 was stronger, its continued effects were also visible, and it wasn't irritative for skin.

FEBS Lett, 1997 Oct 20, 416(2), 221 - 4
Did cyclodextrin glycosyltransferases evolve from alpha-amylases?
del-Rio G, Morett E, Soberon X.
The hydrolytic enzymes, alpha-amylases, and the cyclodextrin glycosyltransferases (CGTases) are key enzymes in the depolymerization of starch . These two groups of enzymes are evolutionarily related . We propose that the transferase activity is likely to have evolved from an ancestral hydrolase . Sequence analysis provides support for this hypothesis . Consequently, we have conducted an experimental study to test the possible adaptive value for evolving a CGTase . We found that when an alpha-amylase and a CGTase are combined more glucose is generated from starch than would be expected from the independent action of either of these enzymes . Thus, we propose that the biological role of CGTases is to work in concert with alpha-amylases for the efficient saccharification of starch . This observation can be useful in industrial processes aimed at producing syrups with high contents of glucose or maltose.

Eur J Immunol, 1997 Oct, 27(10), 2571 - 8
Chemoattractant receptor cross talk as a regulatory mechanism in leukocyte adhesion and migration; Campbell JJ et al.; Leukocytes express multiple chemoattractant receptors that can trigger adhesion and direct their migration . Regulation of such proadhesive and migratory responses must often occur in a complex cytokine milieu in vivo, in which multiple receptors may be engaged simultaneously or sequentially, Here we have examined the interplay between interleukin-8 (IL-8) receptor and formyl peptide receptor (fPR)-stimulation and its consequences for leukocyte adhesion and chemotactic responses . IL-8 has no significant effect on fMLP-stimulated adhesion and migration of human neutrophils, indicating that leukocytes have the potential to respond to sequential proadhesive and chemoattractant stimuli during homing and targeted migration . In contrast, fMLP at > or = 10 nM totally abrogated proadhesive and chemoattractant responses to IL-8, a trnas effect to which the fPR itself is relatively resistant . N-formyl peptides are released by invasive bacteria and lysed cells, and the dominance of the fPR may ensure that signals from these terminal phagocyte targets can override host-derived recruitment signaling through IL-8 and other chemokine receptors . Asymmetric inhibition of adhesion-triggering responses is also observed in lymphoid cells transfected with IL-8 receptor A and fPR, but in this cellular context chemotactic responses are bidirectionally abrogated, suggesting the potential for downstream desensitization of motility programs as well . Cross talk between chemoattractant receptors and their signaling pathways may help target leukocyte migration in the context of complex chemoattractant arrays in vivo.

Nature, 1997 Nov 13, 390(6656), 172 - 5
Impaired mast cell-dependent natural immunity in complement C3-deficient mice; Prodeus AP et al.; The complement system is widely regarded as essential for normal inflammation, not least because of its ability to activate mast cells . However, recent studies have called into question the importance of complement in several examples of mast cell-dependent inflammatory responses . To investigate the role of complement in mast cell-dependent natural immunity, we examined the responses of complement-deficient mice to caecal ligation and puncture, a model of acute septic peritonitis that is dependent on mast cells and tumour necrosis factor-alpha (TNF-alpha) . We found that C4- or C3-deficient mice were much more sensitive to caecal ligation and puncture than wild-type (WT) controls (100% versus 20% in 24-h mortality, respectively) . C3-deficient mice also exhibited reductions in peritoneal mast cell degranulation, production of TNF-alpha, neutrophil infiltration and clearance of bacteria . Treating the C3-deficient mice with purified C3 protein enhanced activation of peritoneal mast cells, TNF-alpha production, neutrophil recruitment, opsonophagocytosis of bacteria and resistance to caecal ligation and puncture, confirming that the defects were complement-dependent . These results provide formal evidence that complement activation is essential for the full expression of innate immunity in this mast cell-dependent model of bacterial infection.

Chest, 1997 Nov 5, 112(5), 1189 - 96
Relationship between preoperative endotoxin immune status, gut perfusion, and outcome from cardiac valve replacement surgery; Hamilton-Davies C et al.; STUDY OBJECTIVE: Endotoxin is a powerful trigger of systemic inflammation . Since cardiac surgery exposes patients to endotoxemia, this study was set up to define the relationship between preoperative endogenous endotoxin immune status, gut perfusion, and outcome following cardiac valve replacement surgery . DESIGN: Observational study . SETTING: University hospital . PATIENTS: Fifty-nine consecutive patients undergoing cardiac valve replacement . MEASUREMENTS AND MAIN RESULTS: Blood was assayed for IgG and IgM endotoxin core antibody (EndoCAb) levels preoperatively, immediately postoperatively, and at 4 h and 24 h postoperatively . Intraoperative gut mucosal perfusion was assessed using gastric tonometry . Complications were assessed for groups above and below the median EndoCAb value of a healthy population (100 median units micro/mL) . Of the 59 patients, 12 developed at least one of a set of predefined complications . Of these 12, all had preoperative levels of IgM EndoCAb below 100 MU/mL (p<0.025) . Eleven had IgG EndoCAb levels below 100 MU/mL (0.05<p<0.1) . There was no relationship between the fall in gastric intramucosal pH and exposure to endotoxin as implied by the fall in unbound IgM EndoCAb levels, although the specificity of tonometry for predicting complications could be improved by considering the patient's preoperative EndoCAb status . CONCLUSIONS: Preoperative EndoCAb levels were related to poor outcome following cardiac surgery and may be used to improve the specificity of GI tonometry in predicting postoperative complications.

Clin Exp Immunol, 1997 Nov, 110(2), 277 - 84
Antigen-presenting properties of gingival fibroblasts in chronic adult periodontitis; Wassenaar A et al.; Chronic periodontitis is characterized by dense infiltrations of T lymphocytes in the connective tissue, which consists mainly of gingival fibroblasts . It is becoming increasingly clear that T lymphocytes and gingival fibroblasts are capable of influencing each other . For example, the T cell cytokine interferon-gamma (IFN-gamma) is able to induce MHC class II molecules on the surface of several cell types, including gingival fibroblasts . Histological sections of chronically inflamed gingival tissue showed a great number of CD4+ and CD8+ T cells that produced IFN-gamma, and in addition showed abundant expression of MHC class II molecules on gingival fibroblasts . Therefore, we investigated whether these gingival fibroblasts acquire the capacity to carry out MHC class II-restricted functions such as antigen presentation to local T cells . In this study, we show that IFN-gamma-treated gingival fibroblasts were able to function as antigen-presenting cells (APC) for superantigen-mediated T cell proliferation . However, these fibroblasts failed to present whole-cell antigens of periodontitis-associated bacteria . Moreover, gingival fibroblasts inhibited the presentation of the whole-cell antigens of these bacteria by professional APC . This inhibition could be overcome by the addition of IL-2 . These results suggest that gingival fibroblasts play an important role in the local specific immune response in chronic inflammatory periodontal lesions by regulating the response of infiltrating T cells.

Arch Surg, 1997 Nov, 132(11), 1231 - 6
Pancreatic ascites as a powerful inducer of inflammatory cytokines . The role of known vs unknown factors; Denham W et al.; OBJECTIVES: To determine if pancreatic ascites will induce interleukin 1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF-alpha) production outside the pancreas and examine the possible components responsible . DESIGN: Severe pancreatitis was induced in rats (n = 30) by pancreatic duct infusion with 4% glycodeoxycholic acid; pancreatic ascites was collected 18 hours later . In vitro studies used quiescent murine splenic or pulmonary macrophages (10(5)/mL) which were exposed to media alone (control), trypsin, chymotrypsin, cathepsin-B, 20% ascites (vol/vol), 50% ascites, or endotoxin (lipopolysaccharide, 10 micrograms/mL, positive control) for 4 hours . Subsequently, pancreatic ascites was cultured for bacteria and assayed for endotoxin and cytokines (interleukin 1, interleukin 6, interleukin 8, TNF-alpha, or interferon gamma) . The experiments were then repeated using 20% and 50% ascites that was sterile and cytokine-free (SCF ascites) . In vivo studies used 100% (n = 8) or 50% (n = 12) SCF ascites or normal rat serum (control, n = 12) for a 10-second pulmonary lavage (100 microL) in adult mice, with lungs collected at 6 hours for cytokine gene analysis . SETTING: Surgical basic science research laboratory . MAIN OUTCOME MEASURES: Interleukin 1 beta and TNF-alpha gene induction was assessed by quantitative competitive reverse-transcription polymerase chain reaction and cytokine protein production was determined by enzyme-linked immunosorbent assay . RESULTS: Macrophages responded to untested and SCF ascites in a dose-dependent fashion, with a multifold increase in both IL-1 beta and TNF-alpha messenger RNA (mRNA) and protein, which was often more potent than lipopolysaccharide . Expression of IL-1 beta and TNF-alpha mRNA could not be induced by trypsin, chymotrypsin, or cathepsin-B . All animals undergoing lavage with 100% SCF ascites died within 2 hours, while those undergoing lavage with 50% SCF ascites showed a multifold increase in pulmonary IL-1 beta and TNF-alpha mRNA . CONCLUSIONS: Pancreatic ascites contains factors that are capable of inducing IL-1 beta and TNF-alpha production in vitro and in vivo . This effect cannot be reproduced by activated digestive enzymes and is propagated despite the absence of known inducers of cytokines such as bacteria, endotoxin, or other inflammatory cytokines.

Nihon Kyobu Shikkan Gakkai Zasshi, 1997 Aug, 35(8), 878 - 82
{Mycetoma-forming pulmonary nocardiosis and endobronchial polypoid lesion}; Akagawa S et al.; A 46-year-old man was admitted to the hospital for evaluation of a dense infiltrative shadow in the right middle lung field . Bronchoscopic examination revealed a polypoid lesion in the right middle-lobe bronchus (Bb11(5)) . Examination of a biopsy specimen showed a lump with many Nocardia asteroides bacteria . The response to chemotherapy, which included sulfomethoxazole, was poor, and therefore a right middle lobectomy was done . Three mycetomas were found inside the ectatic bronchi in the S5 area . Pulmonary Nocardia mycetoma is rare.

J Zoo Wildl Med, 1997 Sep, 28(3), 260 - 6
Treatment of gastritis in cheetahs (Acinonyx jubatus); Wack RF et al.; Three cheetahs (Acinonyx jubatus) had a clinical history of chronic spiral bacteria-associated gastritis and three cheetahs had no clinical history of gastritis . Gastric biopsies were obtained from all six cheetahs prior to treatment for gastritis and 3 wk and 1 yr posttreatment . The cheetahs were treated with tetracycline hydrochloride 500 mg p.o . q.i.d., metronidazole 250 mg p.o . q.i.d., and bismuth subsalicylate 300 mg p.o . q.i.d . Each drug was administered concurrently for 7 days . Following this treatment, each cheetah was maintained on 300 mg bismuth subsalicylate p.o . s.i.d . for 1 yr . The three cheetahs with a history of gastritis were culture positive for Helicobacter acinonyx and remained positive during the entire study . The three cheetahs with no clinical history of gastritis were culture negative for H . acinonyx, but gastric biopsies revealed Gastrospirillum-like bacteria (tentatively named Helicobacter heilmannii) pretreatment . Gastric biopsies were negative for H . heilmannii on subsequent examinations . Although the treatment did not eradicate H . acinonyx, it did provide symptomatic relief from the vomiting, anorexia, and weight loss associated with clinical gastritis . The use of endoscopically guided gastric mucosal biopsies for urease testing and histopathologic examination of Warthin-Starry-stained sections is a sensitive and specific method of diagnosing spiral bacteria-associated gastritis . Treatment of spiral bacteria-associated gastritis in cheetahs should include the rational use of antibiotics (tetracycline or amoxicillin and metronidazole), bismuth compounds, and omeprazole and evaluation of husbandry methods to reduce stress.

Mol Carcinog, 1997 Oct, 20(2), 216 - 23
High-affinity binding of the cell cycle-regulated transcription factors E2F1 and E2F4 to benzo{a}pyrene diol epoxide-DNA adducts; Johnson DG et al.; Previous studies indicated that DNA adducts formed by a carcinogenic diol epoxide, 7r,8t-dihydroxy-9t, 10t-epoxy-7,8,9,10-tetrahydrobenzo{a}pyrene (BPDE), can increase the affinity of the transcription factor Sp1 for DNA sequences that are not normally specific binding sites . It was suggested that adduct-induced bends in the DNA were responsible for this behavior . The cell cycle-regulated transcription factor E2F is also known to bend DNA upon binding . When partially purified E2F was tested in a gel mobility-shift assay, binding to a target DNA containing two consensus E2F-binding sites was enhanced by prior modification of the DNA with BPDE . Recombinant human E2F1, E2F4, and DP1 fusion proteins were affinity purified from bacteria expressing these genes . A combination of either E2F1 or E2F4 with their dimerization partner, DP1, gave preparations that exhibited binding to the E2F site-containing DNA fragment . In both cases, the proteins exhibited much higher apparent affinity for BPDE-modified DNA than for unmodified DNA . In addition, BPDE-modified DNA was a better competitor for the binding than unmodified DNA . Heterologous DNA that contained no consensus E2F binding motifs also competed well for E2F binding when modified with BPDE . In contrast, transcription factor that does not bend DNA appreciably (GAL4) did not show enhanced affinity for BPDE-modified DNA . These findings suggest that numerous transcription factors that bend DNA may bind with anomalously high affinity to sequences that contain carcinogen-DNA adducts.

Eur J Med Res, 1996 May 24, 1(8), 387 - 92
The efficacy of an oral immunostimulant in treating periodontitis - a pilot study; Neumann C et al.; The effect of an oral immunostimulant on adult periodontitis was evaluated in a pilot study . The preparation is successfully administered in respiratory tract infections but has not been used in oral medicine . 11 patients were treated with a bacterial lysate for three months after completing a hygiene phase preceding the study protocol . At day 0 and after 30, 60, and 90 days of medication, parameters characterizing disease activity (bleeding on probing, probing depth, clinical attachment loss and suppuration) and oral hygiene (plaqueindex) were recorded and compared to 10 controls . The treatment resulted in reduced gingival inflammatory activity and diminishing probing depths which was significant compared to the controls (p < 0.001) . The exact mechanism of action induced by immunostimulant therapy remains to be clarified . The promising results of this pilot study offer a new aspect in the therapy of periodontal disease . Further investigations are necessary to define the therapeutic value of this treatment in oral medicine.

Curr Opin Pulm Med, 1996 May, 2(3), 213 - 7
Diagnosis of pneumonia; Wunderink RG; The multitude of studies on the diagnosis of pneumonia published in the past year testifies to the fact that the best diagnostic strategy remains undefined . For community-acquired pneumonia, the etiologic agent can be diagnosed in a high percentage of patients if extensive serologic testing is used . Unfortunately, standard diagnostic tools, including blood cultures, have a low yield . Newer diagnostic techniques offer some hope for an etiologic diagnosis at a time when therapeutic decisions can be made . For nosocomial pneumonia in the nonventilated patient, transthoracic needle aspiration appears to have good accuracy with a low complication rate . For ventilator-associated pneumonia, research on diagnostic methods has yielded important insights into the disease process itself . Unfortunately, consensus regarding the most appropriate diagnostic tool has not been achieved.

Insect Mol Biol, 1997 Nov, 6(4), 357 - 68
Mosquito clathrin heavy chain: analysis of protein structure and developmental expression in the ovary during vitellogenesis; Kokoza VA et al.; We have deduced the amino acid sequences of clathrin heavy chain (CHC) polypeptides based on cDNA and genomic clones from the mosquito, Aedes aegypti . Two isoforms which differ in the very beginning of the N-terminal domain, ovary-specific AaCHCa and somatic-specific AaCHCb, were identified, characterized and compared to one another as well as to CHC polypeptides from different species . The 1682 amino acid sequence of the AaCHCa isoform predicts a molecular mass (M{r}) of 191,743 daltons and an isoelectric point of 5.80, whereas the 1674 amino acid sequence of the AaCHCb isoform predicts a M(r) of 191,033 daltons and an isoelectric point of 5.71 . Both mosquito AaCHC isoforms are highly conserved, with full-sequence identities of 88% to Drosophila melanogaster, 81% to mammal (rat, cow and human), 71% to C . elegans, 58% to Dictyostelium discoideum, and 49% to yeast CHC polypeptides . The highest degree of conservation is in the middle portion of the mosquito CHC molecule which includes the linker region and extended triskelion arm, with decreasing conservation through the N-terminal domain, trimerization domain, and the relatively diverged C-terminal region . The protein domains do not directly correspond to specific exons of the mosquito AaCHC gene, with the exception of exon 6 which encodes the C-terminal domain of the CHC polypeptide . Polyclonal antibodies raised against a bacteria-expressed AaCHC fusion protein recognized one major band of about 180 kDa in vitellogenic ovary whole-lysate . Immunogold labelling of the AaCHC polypeptide localized it to the coat of coated pits and coated vesicles in oocytes from vitellogenic follicles . Northern blot and in situ hybridization analyses suggest that regulation of AaCHC gene expression in the ovary is complex, and it likely involves both developmental and hormonal signals.

J Exp Biol, 1997 Oct, 200(Pt 20), 2609 - 16
Sulfide acquisition by the vent worm Riftia pachyptila appears to be via uptake of HS-, rather than H2S; Goffredi SK et al.; Deep-sea hydrothermal vents are home to a variety of invertebrate species, many of which host chemosynthetic bacteria in unusual symbiotic arrangements . The vent tubeworm Riftia pachyptila (Vestimentifera) relies upon internal chemolithoautotrophic bacterial symbionts to support its large size and high growth rates . Because of this, R . pachyptila must supply sulfide to the bacteria, which are far removed from the external medium . Internal H2S ({H2S+HS-+S2-}) can reach very high levels in R . pachyptila (2-12mmoll-1 in the vascular blood), most of which is bound to extracellular hemoglobins . The animal can potentially take up sulfide from the environment via H2S diffusion or via mediated uptake of HS-, or both . It was expected that H2S diffusion would be the primary sulfide acquisition mechanism, paralleling the previously demonstrated preferential uptake of CO2 . Our data show, however, that the uptake of HS- is the primary mechanism used by R . pachyptila to obtain sulfide and that H2S diffusion into the worm apparently proceeds at a much slower rate than expected . This unusual mechanism may have evolved because HS- is less toxic than H2S and because HS- uptake decouples sulfide and inorganic carbon acquisition . The latter occurs via the diffusion of CO2 at very high rates due to the maintenance of an alkaline extracellular fluid pH . H2S accumulation is limited, however, to sulfide that can be bound by the hemoglobins, protecting the animal from sulfide toxicity and the symbionts from sulfide inhibition of carbon fixation.

J Wildl Dis, 1996 Oct, 32(4), 665 - 9
Hemorrhagic gastritis in free-living rodents in Idaho; Wilber PG et al.; Between February 1992 and March 1994, four species of rodent from the Snake River Birds of Prey Area near Boise, Idaho (USA) were necropsied . Hemorrhagic gastritis was observed in 16 of 131 Townsend's ground squirrels (Spermophilus townsendii), one of 11 Ord's kangaroo rats (Dipodomys ordii) and the one Great Basin pocket mouse (Perognathus parvus) evaluated . No lesions were observed in 14 white-footed deer mice (Peromyscus maniculatus) . Tissue from one Townsend's ground squirrel was negative for Helicobacter sp.-like bacteria.

J Periodontol, 1997 Oct, 68(10), 996 - 1004
Integrated connective tissue in bioabsorbable barrier material and periodontal regeneration; Zucchelli G et al.; The objective of this study was to evaluate the relationship between integrated connective tissue (ICT), that is, the presence of connective tissue into the membrane structure, and the clinical outcome of membrane-supported periodontal surgery . Twenty-six systemically healthy subjects affected by chronic adult periodontitis were enrolled in the study . One tooth site per patient, associated with an angular bony defect and an attachment loss of > 7 mm, was selected to be treated by means of a guided tissue regeneration procedure using a bioabsorbable membrane . Barrier material was surgically removed after 4 weeks for SEM analysis . For each treated site, the difference in clinical attachment loss, probing depth, and gingival recession between the baseline examination and follow-up 6 months after the second surgery was calculated . Gain of attachment was statistically (P < 0.001) greater in sites with no membrane exposure when compared to sites with exposed barrier material (5.5 +/- 1.0 vs . 4.0 +/- 0.6), while further gingival recession was greater (3.0 +/- 0.9 vs . 2.1 +/- 0.5) in sites with clinically exposed membranes . The results of SEM analysis revealed that when connective tissue structures were observed on membrane surfaces, no bacteria could be detected; conversely, areas heavily colonized by bacteria did not show the presence of connective tissue . Regression analysis indicated that integrated connective tissue on the external layer of the barrier material was positively correlated with the amount of attachment gain and negatively with the amount of gingival recession . Bacterial colonization of the membrane was negatively correlated with attachment gain and positively with gingival recession . It was concluded that connective tissue integration is an important biological phenomenon in preventing membrane exposure and bacterial plaque colonization and thus in enhancing the clinical outcome following guided tissue regeneration surgery.

Gene, 1997 Oct 15, 199(1-2), 133 - 7
Direct cloning of the Brassica S locus by using a P1-derived artificial chromosome (PAC) vector; Suzuki G et al.; Self-incompatibility of Brassica is regulated by the S locus, which contains several genes including SLG and SRK . We found that both SLG and SRK genes were located at an approx . 80-kb MluI fragment in an S9 haplotype of B . campestris . Therefore, we cloned this MluI fragment into a BssHII site of the P1-derived artificial chromosome (PAC) vector . The utility of the direct cloning method is discussed in this study.

Gene, 1997 Oct 15, 199(1-2), 93 - 9
The sequences of hypF, hypC and hypD complete the hyp gene cluster required for hydrogenase activity in Bradyrhizobium japonicum; Olson JW et al.; A region of DNA 6 kb downstream of the hydrogenase (H2ase) structural genes and directly downstream of the hypB gene of Bradyrhizobium japonicum was shown by mutational analysis to be necessary for H2ase synthesis . Sequencing of this region revealed two complete open reading frames, and the 5' fragment of a third ORF . They encode proteins with homologies to the HypF, HypC and the N-terminus of HypD from other H2ase-containing organisms . The hypF of B . japonicum encodes a 753-aa protein with a predicted molecular mass of 80.3 kDa that contains the two zinc-finger motifs characteristic of other HypF proteins . The hypC encodes a 85-aa protein with a predicted molecular mass of 8.4 kDa . The 5' portion of hypD, which encodes the first 35 aa, upon combining with the previously reported C-terminus of HypD, designated HypD' (Van Soom et al . (1993) Mol . Gen . Genet . 239, 235-240) encodes a protein with a predicted molecular mass of 42.4 kDa . Complementation studies on a H2 uptake defective strain of B . japonicum containing a polar mutation in the hyp operon revealed that the products of the hyp F, C, D, E genes are required for H2ase production . Evidence is also presented that the hyp genes are co-transcribed from a large operon together with the downstream genes hupGHIJK, making a polycistronic message of 11 genes.

Mutat Res, 1997 Oct 6, 379(2), 167 - 75
QSAR treatment of multiple toxicities: the mutagenicity and cytotoxicity of quinolines; Smith CJ et al.; A series of 15 quinoline congeners were assayed for mutagenicity and cytotoxicity in the Ames test using strain TA100 bacteria . Statistical analysis of the data allowed simultaneous determination of the mutagenicity and cytotoxicity of each quinoline . These data were used to develop three quantitative structure-activity relationships (QSAR) . In all three QSAR, the strength of the relationship between hydrophobicity (as measured by log P) and biological activity was similar as h was near 1 in all three cases . For the mutagenicity of these quinolines, both hydrophobic and steric interactions appear to be important . In contrast, the cytotoxicity is mainly affected by increasing hydrophobicity and by the addition of electron withdrawing substituents to the quinoline ring . Comparison to other QSAR from our laboratory and others lends support to these findings . Both simultaneous consideration of different biological activities and the comparison of newly developed QSAR with previous data for the purpose of lateral validation should be encouraged in future QSAR studies.

J Mol Neurosci, 1997 Aug, 9(1), 35 - 48
A chimeric tyrosine/tryptophan hydroxylase . The tyrosine hydroxylase regulatory domain serves to stabilize enzyme activity; Mockus SM et al.; The neurotransmitter biosynthetic enzymes, tyrosine hydroxylase (TH), and tryptophan hydroxylase (TPH) are each composed of an amino-terminal regulatory domain and a carboxyl-terminal catalytic domain . A chimeric hydroxylase was generated by coupling the regulatory domain of TH (TH-R) to the catalytic domain of TPH (TPH-C) and expressing the recombinant enzyme in bacteria . The chimeric junction was created at proline 165 in TH and proline 106 in TPH because this residue is within a conserved five amino-acid span (ValProTrpPhePro) that defines the beginning of the highly homologous catalytic domains of TH and TPH . Radioenzymatic activity assays demonstrated that the TH-R/TPH-C chimera hydroxylates tryptophan, but not tyrosine . Therefore, the regulatory domain does not confer substrate specificity . Although the TH-R/TPH-C enzyme did serve as a substrate for protein kinase (PKA), activation was not observed following phosphorylation . Phosphorylation studies in combination with kinetic data provided evidence that TH-R does not exert a dominant influence on TPH-C . Stability assays revealed that, whereas TH exhibited a t1/2 of 84 min at 37 degrees C, TPH was much less stable (t1/2 = 28.3 min) . The stability profile of TH-R/TPH-C, however, was superimposable on that of TH . Removal of the regulatory domain (a deletion of 165 amino acids from the N-terminus) of TH rendered the catalytic domain highly unstable, as demonstrated by a t1/2 of 14 min . The authors conclude that the regulatory domain of TH functions as a stabilizer of enzyme activity . As a corollary, the well-characterized instability of TPH may be attributed to the inability of its regulatory domain to stabilize the catalytic domain.

Avian Dis, 1997 Jul-Sep, 41(3), 670 - 5
Pathogenicity of a strain of Trichomonas gallinarum in turkeys and its possible interaction with cecal coccidia; Norton RA; The pathogenicity of Trichomonas gallinarum (TG) in turkeys and chickens was assessed in a series of four experiments . TG was shown to be resistant to freezing for a period of 1 hr at -20 C; birds administered an emulsion of previously frozen TG were readily infected . Young birds receiving this inoculum were more likely to be infected with TG in both ceca compared with birds administered TG emulsion that had remained at room temperature for the same length of time . In this and other experiments, birds infected with the parasite consistently produced a yellow frothy liquid in the ceca, as well as small raised papulae on the mucosal surface of the ceca . Histologically, the lesions were located in the lamina propria, with openings that extended from the apex of the lesion to the crypts . The lamina propria was consistently infiltrated by lymphocytes and scattered heterophiles . Although TG is likely involved in the pathogenesis of the lesions, the resulting pathology could not be linked definitively to TG alone because inoculation was performed with a cecal contents homogenate containing significant numbers of cecal bacteria . Combined infections of TG and Eimeria adenoides (EA) were also studied . Turkeys administered both parasites were more frequently infected with TG in both ceca compared with those that received TG alone . Ceca infected with TG alone tended to be enlarged and gas filled, whereas those infected with the combination of TG and EA were smaller and usually lacked the yellow frothy liquid contents.

Avian Dis, 1997 Jul-Sep, 41(3), 654 - 60
Amplification of avian reovirus RNA using the reverse transcriptase-polymerase chain reaction; Xie Z et al.; A reverse transcriptase-polymerase chain reaction method was developed for the detection of avian reovirus . The origin of primers was from the S1 gene of the avian reovirus genome . A reovirus-specific 532-base pair cDNA product was amplified by these primers from six reference strains and 23 field isolates of avian reoviruses, but not from seven different avian pathogenic viruses and bacteria . As little as 1 pg of avian reovirus RNA was detected using gel electrophoresis and Southern blot hybridization.

Vet Microbiol, 1997 Sep, 57(2-3), 199 - 213
Dermatophilus congolensis: strain differences in expression of phospholipase activities; Masters AM et al.; Interactions between Dermatophilus congolensis strains and with other bacteria of known haemolytic activities were used to elucidate the complex nature of haemolytic activities present in various D . congolensis strains . This was further analysed by measuring their specific phospholipase activities against defined substrates by thin layer chromatography . D . congolensis strains demonstrated haemolytic interactions (synergistic or antagonistic) with other D . congolensis strains and also other species of bacteria . Most isolates expressed lyso-phospholipase-D activity, while various strains also expressed sphingomyelinase-D activity, phospholipase-A versus phosphatidylcholines and/or cephalins, phospholipase-D versus phosphatidylcholines or all these activities, under the culture conditions used.

Biochemistry, 1997 Nov 4, 36(44), 13617 - 28
Evaluation of the role of specific acidic amino acid residues in electron transfer between the flavodoxin and cytochrome c3 from Desulfovibrio vulgaris; Feng Y et al.; A hypothetical model for electron transfer complex between cytochrome c3 and the flavodoxin from the sulfate-reducing bacteria Desulfovibrio vulgaris has been proposed, based on electrostatic potential field calculations and NMR data {Stewart, D . E., LeGall, J . , Moura, I., Moura, J . J . G., Peck, H . D., Jr., Xavier, A . V., Weiner, P . K., & Wampler, J . E . (1988) Biochemistry 27, 2444-2450} . This modeled complex relies primarily on the formation of five ion pairs between lysine residues of the cytochrome and acidic residues surrounding the flavin mononucleotide cofactor of the flavodoxin . In this study, the role of several acidic residues of the flavodoxin in the formation of this complex and in electron transfer between these two proteins was evaluated . A total of 17 flavodoxin mutants were studied in which 10 acidic amino acids--Asp62, Asp63, Glu66, Asp69, Asp70, Asp95, Glu99, Asp106, Asp127, and Asp129--had been permanently neutralized either individually or in various combinations by substitution with their amide amino acid equivalent (i.e., asparate to asparagine, glutamate to glutamine) through site-directed mutagenesis . The kinetic data for the transfer of electrons from reduced cytochrome c3 to the various flavodoxin mutants do not conform well to a simple bimolecular mechanism involving the formation of an intermediate electron transfer complex . Instead, a minimal electron transfer mechanism is proposed in which an initial complex is formed that is stabilized by intermolecular electrostatic interactions but is relatively inefficient in terms of electron transfer . This step is followed by a rate-limiting reorganization of that complex leading to efficient electron transfer . The apparent rate of this reorganization step was enhanced by the disruption of the initial electrostatic interactions through the neutralization of certain acidic amino acid residues leading to faster overall observed electron transfer rates at low ionic strengths . Of the five acidic residues involved in ion pairing in the modeled complex proposed by Stewart et al . (1988), the kinetic data strongly implicate Asp62, Glu66, and Asp95 in the formation of the electrostatic interactions that control electron transfer . Less certainty is provided by this study for the involvement of Asp69 and Asp129, although the data do not exclude their participation . It was not possible to determine whether the modeled complex represents the optimal configuration for electron transfer obtained after the reorganization step or actually represents the initial complex . The data do provide evidence for the importance of electrostatic interactions in electron transfer between these two proteins and for the existence of alternative binding modes involving acidic residues on the surface of the flavodoxin other than those proposed in that model.

Biochemistry, 1997 Nov 4, 36(44), 13611 - 6
Pulse radiolysis studies on cytochrome cd1 nitrite reductase from Thiosphaera pantotropha: evidence for a fast intramolecular electron transfer from c-heme to d1-heme; Kobayashi K et al.; Electron transfer within cytochrome cd1 from Thiosphaera pantotropha was investigated by the technique of pulse radiolysis . The reduction of the heme centers in this nitrite reductase occurred in two phases as judged from kinetic difference spectra . In the faster phase, radiolytically generated N-methylnicotinamide (NMA) radicals selectively reduced the c-heme of the enzyme . From the absorbance increase at 420 nm, a characteristic of formation of the ferrousc-heme, the second-order rate constant for this electron transfer process was estimated to be 3.8 x 10(9) M-1 s-1 at pH 7.0 . In the slower phase, a decrease of absorption around 420 and 550 nm, corresponding to a reoxidation of the c-heme, was accompanied by an increase of absorption around 460 and 640 nm, characteristic of formation of the reduced d1-heme . This indicated that an intramolecular electron transfer from the c-heme to the d1-heme occurred . The first-order rate constant of this process was calculated to be 1.4 x 10(3) s-1 at pH 7.0 and was independent of the enzyme concentration . In the presence of nitrite the interheme electron transfer rate was not affected, but on a time scale of seconds a new species associated with the d1-heme, having an absorption maximum at 640 nm, was detected and is proposed to reflect ligand binding to this heme . These results suggest the role of the c-heme as the electron acceptor site in cytochrome cd1 and in mediating the electron transfer to the catalytic site of the enzyme . Moreover, the fast interheme electron transfer rate argues against this process being the rate determining step in catalysis.

Infect Immun, 1997 Nov, 65(11), 4892 - 6
Intrapulmonary Hartmannella vermiformis: a potential niche for Legionella pneumophila replication in a murine model of legionellosis; Brieland J et al.; The potential role of inhaled protozoa as a niche for intrapulmonary replication of Legionella pneumophila was investigated in vivo with mutant strains of L . pneumophila which have reduced virulence for the amoeba Hartmannella vermiformis . L . pneumophila AA488 and AA502 were derived from wild-type strain AA100 after transposon mutagenesis . These mutants have reduced virulence for H . vermiformis but are fully virulent for mononuclear phagocytic cells . A/J mice, which are susceptible to replicative L . pneumophila lung infections, were inoculated intratracheally with L . pneumophila AA100, AA488, or AA502 (10{6} bacteria per mouse) or were coinoculated with one of the L . pneumophila strains (10{6} bacteria per mouse) and uninfected H . vermiformis (10{6} amoebae per mouse) . The effect of coinoculation with H . vermiformis on intrapulmonary growth of each L . pneumophila strain was subsequently assessed . In agreement with our previous studies, coinoculation with H . vermiformis significantly enhanced intrapulmonary growth of the parent L . pneumophila strain (AA100) . In contrast, intrapulmonary growth of L . pneumophila AA488 or AA502 was not significantly enhanced by coinoculation of mice with H . vermiformis . These studies demonstrate that L . pneumophila virulence for amoebae is required for maximal intrapulmonary growth of the bacteria in mice coinoculated with H . vermiformis and support the hypothesis that inhaled amoebae may potentiate intrapulmonary growth of L . pneumophila by providing a niche for bacterial replication.

J Bacteriol, 1997 Nov, 179(21), 6674 - 9
Involvement of two alpha-ketoglutarate-dependent dioxygenases in enantioselective degradation of (R)- and (S)-mecoprop by Sphingomonas herbicidovorans MH; Nickel K et al.; Cell extracts of Sphingomonas herbicidovorans MH grown on (R)-mecoprop contained an enzyme activity that selectively converted (R)-mecoprop to 4-chloro-2-methylphenol, whereas extracts of cells grown on (S)-mecoprop contained an enzyme activity selective for the S enantiomer . Both reactions were dependent on alpha-ketoglutarate and ferrous ions . Besides 4-chloro-2-methylphenol, pyruvate and succinate were detected as products of the reactions . Labeling experiments with (18)O2 revealed that both enzyme activities catalyzed a dioxygenation reaction . One of the oxygen atoms of pyruvate and one of the oxygen atoms of succinate were derived from molecular oxygen . Analysis of cell extracts obtained from cells grown on different substrates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that growth on (R)-mecoprop and (S)-mecoprop caused the appearance of prominent protein bands at 34 and 32 kDa, respectively . Both protein bands were present when cells grew on the racemic mixture . The results demonstrate that S . herbicidovorans initiated the degradation of each enantiomer of mecoprop by a specific alpha-ketoglutarate-dependent dioxygenase . By comparing conversion rates of various phenoxy herbicides, we confirmed that the two enzyme activities were distinct from that of TfdA, which catalyzes the first step in the degradation of 2,4-dichlorophenoxyacetic acid in Ralstonia eutropha JMP134.

Drug Metab Dispos, 1997 Nov, 25(11), 1234 - 41
Heterologous expression of human drug-metabolizing enzymes; Guengerich FP et al.; This article is a report on a symposium held at the March 1997 meeting of the American Society for Pharmacology and Experimental Therapeutics in San Diego . Current developments in the heterologous expression of cytochrome P450, NADPH-cytochrome P450 reductase, glutathione transferase, and UDP-glucuronosyltransferase enzymes are described . Systems include bacteria, insect cells, and transient and stable mammalian cells . Uses of the products are described for discernment of which enzymes are involved in metabolism of drugs, genotoxicity assays, mutagenesis (for structure-activity relationships), large scale production of enzyme products, antibody production, and production of proteins for biophysical studies.

Structure, 1997 Oct 15, 5(10), 1339 - 59
The coupling of light-induced electron transfer and proton uptake as derived from crystal structures of reaction centres from Rhodopseudomonas viridis modified at the binding site of the secondary quinone, QB; Lancaster CR et al.; BACKGROUND: In a reaction of central importance to the energetics of photosynthetic bacteria, light-induced electron transfer in the reaction centre (RC) is coupled to the uptake of protons from the cytoplasm at the binding site of the secondary quinone (QB) . In the original structure of the RC from Rhodopseudomonas viridis (PDB entry code 1PRC), the QB site was poorly defined because in the standard RC crystals it was only approximately 30% occupied with ubiquinone-9 (UQ9) . We report here the structural characterization of the QB site by crystallographic refinement of UQ9-depleted RCs and of complexes of the RC either with ubiquinone-2 (UQ2) or the electron-transfer inhibitor stigmatellin in the QB site . RESULTS: The structure of the RC complex with UQ2, refined at 2.45 A resolution, constitutes the first crystallographically reliably defined binding site for quinones from the bioenergetically important quinone pool of biological, energy-transducing membranes . In the UQ9-depleted QB site of the RC structure, refined at 2.4 A resolution, apparently five (and possibly six) water molecules are bound instead of the ubiquinone head group, and a detergent molecule binds in the region of the isoprenoid tail . All of the protein-cofactor interactions implicated in the binding of the ubiquinone head group are also implicated in the binding of the stigmatellin head group . In the structure of the stigmatellin-RC complex, refined at 2.4 A resolution, additional hydrogen bonds stabilize the binding of stigmatellin over that of ubiquinone . The tentative position of UQ9 in the QB site in the original data set (1PRC) was re-examined using the structure of the UQ9-depleted RC as a reference . A modified QB site model, which exhibits greater similarity to the distal ubiquinone-10 (UQ10) positioning in the structure of the RC from Rhodobacter sphaeroides (PDB entry code 1PCR), is suggested as the dominant binding site for native UQ9 . CONCLUSIONS: The structures reported here can provide models of quinone reduction cycle intermediates . The binding pattern observed for the stigmatellin complex, where the ligand donates a hydrogen bond to Ser L223 (where 'L' represents the L subunit of the RC), can be viewed as a model for the stabilization of a monoprotonated reduced intermediate (QBH or QBH-) . The presence of Ser L223 in the QB site indicates that the QB site is not optimized for QB binding, but for QB reduction to the quinol.

Am J Respir Crit Care Med, 1997 Oct, 156(4 Pt 1), 1105 - 13
The systemic inflammatory response in the development of ventilator-associated pneumonia; Bonten MJ et al.; Ventilator-associated pneumonia (VAP) is the most frequent occurring infection among mechanically ventilated patients . The clinical presentation of VAP ranges from relatively benign to a severe illness with septic shock . The influence of VAP on patient outcome has not been elucidated and its effects on the inflammatory response of the host are unknown . In a case-control study, the systemic inflammatory response was investigated in patients developing VAP as compared with control patients matched on duration of mechanical ventilation and underlying diseases . Patients developing VAP (n = 42) were matched to a single control (without VAP), who was matched on seven variables . VAP was diagnosed with bronchoscopic techniques . The inflammatory response, reflected by circulating levels of interleukin-6 (IL-6) and interleukin-8 (IL-8), was determined on the day of diagnosis (or day of matching for controls), 4 and 2 d before diagnosis, and 2 d after diagnosis . The development of VAP was not associated with an increase in circulating levels of IL-6 or IL-8 . Among patients in which VAP was associated with a clinical presentation of severe sepsis or septic shock (n = 10), IL-6 and IL-8 levels increased and were higher than in the corresponding controls . Moreover, 60% of cases with severe sepsis or septic shock died as compared with 20% of their matched controls (p = 0.06) . Mortality rates were similar in patients with uncomplicated VAP and their matched controls (25% and 34%, respectively) . High circulating levels of IL-6 and IL-8 were associated with higher mortality rates . The clinical picture of VAP can be subdivided into different types, ranging from uncomplicated to an infection associated with severe sepsis or septic shock, elevated circulating levels of IL-6 and IL-8, and an increased mortality rate.

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