Microorganism

Kyobu Geka, 1996 Jan, 49(1), 53 - 6
{Reconstruction of chest wall defects with autogenous ribs grafts}; Kawamura M et al.; Three methods of chest wall reconstruction using autogenous rib grafts were reported . Fresh non-vascularized autogenous rib graft, vascularized autogenous ribs with muscle-flap, and pasteurized autogenous rib grafts were the materials used in these techniques . They are less convenient than those with artificial materials but afterwards physiologically more natural chest wall will be reconstructed . The third method (pasteurized rib graft) was applied to 22-year-old female with large recurrent desmoid tumor . Six resected ribs were heated in the saline at 60 degrees C for 30 min . and three of them were returned to the former position . Though tumor cells and bacteria are killed under this condition, these heated bone can be revascularized and replaced by normal bone as early as fresh non-vascularized rib graft.

Infect Immun, 1996 Jan, 64(1), 50 - 4
Immunosuppressive factor from Actinobacillus actinomycetemcomitans down regulates cytokine production; Kurita-Ochiai T et al.; A cytoplasmic soluble fraction of Actinobacillus actinomycetemcomitans Y4 was isolated and characterized as suppressing mitogen-stimulated proliferation of and cytokine production by C3H/HeN mouse splenic T cells . This factor, designated suppressive factor 1 (SF1), was isolated from the supernatant of sonicated whole bacteria and purified by Q-Sepharose Fast Flow column chromatography, DEAE-Sepharose Fast Flow column chromatography, hydroxyapatite high-pressure liquid chromatography (HPLC), and Protein Pack 300 & 125 gel filtration HPLC . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the purified SF1 migrated as a single band corresponding to a molecular mass of 14 kDa . This molecule was protease labile, heat resistant, and noncytotoxic . N'-terminal sequence analysis revealed no homology with any known peptides of periodontopathic bacteria or with any host-derived growth factors . Purified SF1 suppressed the proliferation of mouse splenic T cells which had been stimulated with concanavalin A, as well as suppressing the production of interleukin-2 (IL-2), gamma interferon, IL-4, and IL-5 from CD4+ T cells as 0.1 microgram/ml or more . These data suggest that SF1 produced by the periodontal pathogen A . actinomycetemcomitans functions as a virulence factor by down regulating T-cell proliferation and cytokine production at local defense sites.

Infect Immun, 1996 Jan, 64(1), 197 - 208
Adherence, fibronectin binding, and induction of cytoskeleton reorganization in cultured human cells by Mycoplasma penetrans; Giron JA et al.; Mycoplasma penetrans adhered to cultured human cells, forming clusters that localized to specific areas of the host cell surface . Adherence and cluster formation were inhibited by anti-M . penetrans antibodies, suggesting the involvement of specific adhesin-receptor interactions . Ultrastructural studies showed that after 2 h of infection, mycoplasmas attach to and penetrate the host cell surface . M . penetrans bound selectively to immobilized fibronectin, an interaction which was not inhibited by a 70-kDa fragment containing a heparin-gelatin-binding domain of fibronectin, other matrix glycoproteins, or an RGD tripeptide, suggesting the recognition of other specific binding sites on the fibronectin molecule . A ca . 65-kDa fibronectin-binding protein of M . penetrans was eluted following Sepharose-fibronectin affinity chromatography . Confocal, light, and immunofluorescence microscopy demonstrated that the interaction of M . penetrans with target cells triggers a signal that causes recruitment of several cytoskeletal components, including tubulin and alpha-actinin, and aggregation of phosphorylated proteins . Detergent-soluble mycoplasma proteins with apparent molecular masses of 18, 28, 32, 36, 39, and 41 kDa selectively bound to glutaraldehyde-fixed HEp-2 cells . Our findings offer new insights into understanding the interaction of this human mycoplasma with host target cells.

J Bacteriol, 1996 Jan, 178(2), 505 - 10
Coenzyme F390 synthetase from Methanobacterium thermoautotrophicum Marburg belongs to the superfamily of adenylate-forming enzymes; Vermeij P et al.; Depending on the reduction-oxidation state of the cell, some methanogenic bacteria synthesize or hydrolyze 8-hydroxyadenylylated coenzyme F420 (coenzyme F390) . These two reactions are catalyzed by coenzyme F390 synthetase and hydrolase, respectively . To gain more insight into the mechanism of the former reaction, coenzyme F390 synthetase from Methanobacterium thermoautotrophicum Marburg was purified 89-fold from cell extract to a specific activity of 0.75 mumol.min-1.mg of protein-1 . The monomeric enzyme consisted of a polypeptide with an apparent molecular mass of 41 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . ftsA, the gene encoding coenzyme F390 synthetase, was cloned and sequenced . It encoded a protein of 377 amino acids with a predicted M(r) of 43,280 . FtsA was found to be similar to domains found in the superfamily of peptide synthetases and adenylate-forming enzymes . FtsA was most similar to gramicidin S synthetase II (67% similarity in a 227-amino-acid region) and sigma-(L-alpha-aminoadipyl)-L-cysteine-D-valine synthetase (57% similarity in a 193-amino-acid region) . Coenzyme F390 synthetase, however, holds an exceptional position in the superfamily of adenylate-forming enzymes in that it does not activate a carboxyl group of an amino or hydroxy acid but an aromatic hydroxyl group of coenzyme F420.

J Bacteriol, 1996 Jan, 178(1), 12 - 8
A global signal transduction system regulates aerobic and anaerobic CO2 fixation in Rhodobacter sphaeroides; Qian Y et al.; Complementation of a mutant of Rhodobacter sphaeroides defective in photosynthetic CO2 reduction led to the identification of a gene which encodes a protein that is related to a class of sensor kinases involved in bacterial signal transduction . The nucleotide sequence and deduced amino acid sequence led to the finding that the gene which complemented the mutant is the regB (prrB) gene, previously isolated from both R . sphaeroides and Rhodobacter capsulatus and shown to regulate the anaerobic expression of structural genes required for the synthesis of the reaction center and light-harvesting systems of these organisms . The current investigation indicates that in addition to its role in the regulation of photosystem biosynthesis, regB (prrB) of R . sphaeroides is intimately involved in the positive regulation of the cbbI and cbbII Calvin cycle CO2 fixation operons . In addition to regulating the expression of structural genes encoding enzymes of the primary pathway for CO2 fixation in R . sphaeroides, regB was also found to be required for the expression of a gene(s) important for the putative alternative CO2 fixation pathway(s) of this organism . A mutation in regB also blocked expression of structural genes of the cbb regulon in a strain of R . sphaeroides capable of aerobic CO2-dependent growth in the dark . It is thus apparent that regB is part of a two-component system and encodes a sensor kinase involved in the global regulation of both anoxygenic light-dependent- and oxygenic light-independent CO2 fixation as well as anoxygenic photosystem biosynthesis.

Ann Otol Rhinol Laryngol, 1996 Jan, 105(1), 54 - 7
Comparative perilymph permeability of cephalosporins and its significance in the treatment and prevention of suppurative labyrinthitis; Sun AH et al.; Cephalosporins are nonototoxic antibiotics that provide excellent coverage for almost all bacteria that can cause suppurative labyrinthitis . In this study we performed comparative perilymph permeability determinations of the three cephalosporins that we deemed to have the most clinical potential in these varied situations . Perilymph pharmacokinetic profiles were established for ceftazidime, cefuroxime, and cefotaxime and its metabolite desacetylcefotaxime in 36 guinea pigs by using the technique of high-performance liquid chromatography . At 1, 2, 3, 4, and 6 hours after intravenous administration of the three cephalosporins at a dose of 100 mg/kg of body weight, ceftazidime consistently exhibited the highest perilymph concentration . Desacetylcefotaxime showed the next highest capacity for penetration into perilymph . Keeping in mind that the choice of drug for the treatment of suppurative labyrinthitis should be based foremost on culture and sensitivity studies, we consider ceftazidime to be the first-line agent for treatment and prevention of both meningogenic labyrinthitis and labyrinthitis complicating acute or chronic otitis media.

J Am Coll Surg, 1996 Jan, 182(1), 7 - 11
Necrotizing soft tissue infections: obstacles in diagnosis; Lille ST et al.; BACKGROUND: This study was done to identify obstacles in the early diagnosis and treatment of necrotizing soft tissue infections . STUDY DESIGN: A ten-year retrospective case series was analyzed . RESULTS: Data from 29 patients were analyzed . Among patients undergoing early operation within 24 hours of admission (n = 17) there was one death (6 percent mortality rate); survivors averaged 2.9 operations per patient . By comparison, of patients with delayed operation (n = 12) three died (25 percent mortality rate) and there were 3.6 operations per patients . Positive fine-needle aspiration (FNA) of suspicious lesions, demonstrating either pus or bacteria by Gram's stain, led to early operation in 80 percent of patients tested . Patients with soft tissue gas on radiographs were more likely to undergo early operation (58 percent) . Delayed operation was more common in the absence of radiographic findings . All patients admitted to nonsurgical services had delayed operations . CONCLUSIONS: Suspected necrotizing soft tissue infections require prompt surgical evaluation and early operative exploration . Early operation with definitive surgical therapy initiated within 24 hours of admission is associated with decreased mortality rates . Negative FNA findings, nondiagnostic radiographs, and admission to a nonsurgical service correlate with delay in definitive operative intervention.

Rev Environ Contam Toxicol, 1996, 145, 129 - 73
Atrazine retention and transport in soils; Ma L et al.; No pesticide has been studied as extensively as atrazine . The study of atrazine has contributed to our general understanding of the behavior of pesticides in soils . New knowledge and concepts were evaluated, such as atrazine adsorption kinetics, desorption hysteresis, and preferential flow . Corresponding conceptual models were also proposed to explain the behavior of atrazine in soils . Atrazine adsorption-desorption is the major process affecting atrazine behavior in soils and is mainly affected by organic matter and soil pH . Atrazine in soils is subject to biological and chemical degradations . Hydroxyatrazine, the chemical degradation product, is more strongly adsorbed to soil than atrazine . Deethylatrazine and deisopropylatrazine, the major biological degradation products, are more mobile than atrazine . Hydrolysis of atrazine is soil-surface catalyzed and favored by low soil pH . The overall dissipation rate of atrazine was found to be pseudo first-order . Two distinct and different processes are involved in atrazine movement: slow transport through the soil matrix and rapid movement through macropores . The first process is controlled by adsorption kinetics and degradation reactions and can be well explained by models based on chemical heterogeneity, such as the two-site models and second-order models . The second flow process results from preferential flow through large pores and can be explained by physical nonequilibrium models such as the mobile-immobile and two-flow domain models . Because both processes coexist in atrazine transport, coupling of physical and chemical nonequilibrium models is often necessary and has shown promise in atrazine transport modeling . However, more efforts are needed in estimating model parameters and in developing management-oriented models.

Gene, 1995 Dec 29, 167(1-2), 279 - 83
A single amino-acid change between the antigenically different extracellular serine proteases V2 and B2 from Dichelobacter nodosus; Riffkin MC et al.; Dichelobacter nodosus (Dn), the causative organism of ovine footrot, secrets three distinct types of extracellular serine proteases which have been implicated in virulence . Southern analyses have shown that the proteases are encoded by three separate genes, and the genes encoding an acidic protease V5 and a basic protease have already been characterised from virulent Dn strain 198 . The gene encoding the third protease type, as represented by acidic protease V2, was isolated from an EcoRI-BamHI library of strain 198 genomic DNA by probing with a polymerase chain reaction (PCR) fragment generated with oligodeoxyribonucleotides based on protease V2 amino acid (aa) sequences . A further clone from an RsaI library was isolated to complete the 5' region of the gene to yield an ORF of 1803 bp encoding a protein precursor of 601 aa . The acidic protease V2 gene, aprV2, shows the same precursor structure as the bprV and aprV5 genes with 72% and 69% similarity at the nucleotide (nt) level and with 73% and 69% similarity at the aa level, respectively . As monoclonal antibodies consistently distinguish the virulent (V) and benign (B) forms of this protease, the gene encoding the acidic protease B2 from benign Dn strain 305 was isolated using the PCR and characterized to investigate the molecular basis for this difference in antigenicity . A 2-bp substitution in a single codon was identified which appeared to be responsible for a change of epitope.

J Biol Chem, 1995 Dec 29, 270(52), 31244 - 8
Regulation of NF-kappa B through the nuclear processing of p105 (NF-kappa B1) in Epstein-Barr virus-immortalized B cell lines; Baldassarre F et al.; Transcription factors of the NF-kappa B/Rel family are retained in the cytoplasm as inactive complexes through association with I kappa B inhibitory proteins . Several NF-kappa B activators induce the proteolysis of I kappa B proteins, which results in the nuclear translocation and DNA binding of NF-kappa B complexes . Here, we report a novel mechanism of NF-kappa B regulation mediated by p105 (NF-kappa B1) precursor of p50 directly at the nuclear level . In Epstein-Barr virus-immortalized B cells, p105 was found in the nucleus, where it was complexed with p65 . In concomitance with NF-kappa B activation, mitomycin C induced the processing of p105 to p50 in the nucleus, while it did not affect the steady-state protein levels of I kappa B alpha and p105 in the cytoplasm . Differently, phorbol 12-myristate 13-acetate induced a significant proteolysis of both I kappa B alpha and p105 in the cytoplasm, while it did not affect the protein level of p105 in the nucleus . These results suggest that in Epstein-Barr virus-positive B cell lines the nuclear processing of p105 can contribute to NF-kappa B activation in response to specific signaling molecules, such as DNA-damaging agents.

Transplantation, 1995 Dec 27, 60(12), 1504 - 10
Genetic control of the humoral immune response to xenografts . II . Monoclonal antibodies that cause rejection of heart xenografts are encoded by germline immunoglobulin genes; Borie DC et al.; The early phases of the rejection of xenografts exchanged between closely related species are dominated by a vigorous humoral immune response . We have recently used a linker-mediated polymerase chain reaction (LM-PCR) to generate Ig heavy and light chain-specific cDNA libraries to examine the Ig gene control of a prototypic IgM monoclonal antibody, HAR-1, that causes the hyperacute rejection of hamster xenografts . Recombinant clones from the library were screened directly from bacterial colonies by PCR and the nucleic acid sequences of the clones established . Our results demonstrate that the HAR-1 hybridoma is encoded by Ig VH and JH genes in a germline configuration . Comparison of the cDNA sequence for HAR-1 VH with the germline equivalent of this gene isolated from newborn LEW liver (provisionally designated VHHAR-1) showed that the two VH sequences share a nucleic acid identity of 99.3% . Similarly, the HAR-1 monoclonal uses a Ig JH gene that is 98.2% identical with the JH1 nucleic acid sequence available in the GeneBank . The use of Ig VH and JH genes in a germline configuration is similar to that seen with polyreactive natural antibodies to infectious agents and autoantibodies . These humoral responses are thought to be the result of the stimulation of a T cell-independent subset of B cells, the B-1a/B-1b subset, that is responsible for producing antibodies that serve as a primitive humoral (natural antibody) defense mechanism against infectious diseases . Our results suggest that the humoral component of the rejection of xenografts in the hamster-to-rat model may represent the stimulation of this type of B cell antibody response by xenogeneic target antigens that share antigenic epitopes with bacteria and other infectious agents.

Nucleic Acids Res, 1995 Dec 25, 23(24), 5048 - 54
Specific binding of the replication protein of plasmid pPS10 to direct and inverted repeats is mediated by an HTH motif; Garcia de Viedma D et al.; The initiator protein of the plasmid pPS10, RepA, has a putative helix-turn-helix (HTH) motif at its C-terminal end . RepA dimers bind to an inverted repeat at the repA promoter (repAP) to autoregulate RepA synthesis . {D . Garcia de Viedma, et al . (1996) EMBO J . in press} . RepA monomers bind to four direct repeats at the origin of replication (oriV) to initiate pPS10 replication This report shows that randomly generated mutations in RepA, associated with defficiencies in autoregulation, map either at the putative HTH motif or in its vicinity . These mutant proteins do not promote pPS10 replication and are severely affected in binding to both the repAP and oriV regions in vitro . Revertants of a mutant that map in the vicinity of the HTH motif have been obtained and correspond to a second amino acid substitution far upstream of the motif . However, reversion of mutants that map in the helices of the motif occurs less frequently, at least by an order of magnitude . All these data indicate that the helices of the HTH motif play an essential role in specific RepA-DNA interactions, although additional regions also seem to be involved in DNA binding activity . Some mutations have slightly different effects in replication and autoregulation, suggesting that the role of the HTH motif in the interaction of RepA dimers or monomers with their respective DNA targets (IR or DR) is not the same.

J Biol Chem, 1995 Dec 22, 270(51), 30453 - 7
Purification and characterization of a novel ADP-dependent glucokinase from the hyperthermophilic archaeon Pyrococcus furiosus; Kengen SW et al.; Pyrococcus furiosus uses a modified Embden-Meyerhof pathway during growth on poly- or disaccharides . Instead of the usual ATP-dependent glucokinase, this pathway involves a novel ADP-dependent (AMP-forming) glucokinase . The level of this enzyme and some other glycolytic enzymes appeared to be closely regulated by the substrate . Growth on cellobiose resulted in a high specific activity of 0.96 units mg-1, whereas on pyruvate a 10-fold lower activity was found . The ADP-dependent glucokinase was purified 1350-fold to homogeneity . The oxygen-stable enzyme had a molecular mass of 93 kDa and was composed of two identical subunits (47 kDa) . The glucokinase was highly specific for ADP, which could not be replaced by ATP, phosphoenolpyruvate, GDP, PPi, or polyphosphate . D-Glucose could be replaced only by 2-deoxy-D-glucose, albeit with a low efficiency . The Km values for D-glucose and ADP were 0.73 and 0.033 mM, respectively . An optimum temperature of 105 degrees C and a half-life of 220 min at 100 degrees C are in agreement with the requirements of this hyperthermophilic organism . The properties of the glucokinase are compared to those of less thermoactive gluco/hexokinases.

Carbohydr Res, 1995 Dec 20, 278(2), 289 - 300
Synthesis of 2-(4-aminophenyl)ethyl 3-deoxy-5-O-(3,4,6-tri-O-beta-D- glucopyranosyl-alpha-D-glucopyranosyl)-alpha-D-manno-oct-2-ulopyrano sid onic acid, a highly branched pentasaccharide corresponding to structures found in lipopolysaccharides from Moraxella catarrhalis; Ekelof K et al.; Syntheses of the pentasaccharide 2-(4-aminophenyl)ethyl 3-deoxy-5-O-(3,4,6- tri-O-beta-D-glucopyranosyl-alpha-D-glucopyranosyl)-alpha-D-manno-oct-2- ulopyranosidonic acid and of the tetrasaccharide 3,4,6-tri-O-beta-D-glucopyranosyl-alpha-D-glucopyranoside, both as its methyl and 2-(4-trifluoro-acetamidophenyl)ethyl glycoside, are described . These oligosaccharides correspond to structures found in the lipopolysaccharide of Moraxella catarrhalis and were needed for biological experiments aimed at producing antibodies against the bacteria . The best way to introduce the glucopyranosyl groups into the 3-, 4-, and 6-positions of the branched target compounds was found to be a one-step reaction using a 3,4,6-triol as acceptor and 2,3,4,6-tetra-O-benzoyl-D-glucopyranosyl bromide as donor in a silver trifluoromethanesulfonate-promoted coupling . The spacer arm, necessary for the formation of immunoactive glycoconjugates, was introduced into the glucose moiety via a dimethyl(methylthio)sulfonium trifluoromethanesulfonate-promoted reaction using the ethyl thioglucoside as donor, whereas for Kdo, the acetylated glycal derivative, methyl 4,5,7,8-tetra-O-acetyl-2,6-anhydro-3-deoxy-D-manno-oct-2-enonate, was used as donor and phenylselenyl trifluoromethanesulfonate as a stereocontrolling promoter.

Proc Natl Acad Sci U S A, 1995 Dec 19, 92(26), 12384 - 8
Characterization of the wild-type form of 4a-carbinolamine dehydratase and two naturally occurring mutants associated with hyperphenylalaninemia; Johnen G et al.; The characterization of 4a-carbinolamine dehydratase with the enzymatically synthesized natural substrate revealed non-Michaelis-Menten kinetics . A Hill coefficient of 1.8 indicates that the dehydratase exists as a multisubunit enzyme that shows cooperativity . A mild form of hyperphenylalaninemia with high 7-biopterin levels has been linked to mutations in the human 4a-carbinolamine dehydratase gene . We have now cloned and expressed two mutant forms of the protein based on a patient's DNA sequences . The kinetic parameters of the mutant C82R reveal a 60% decrease in Vmax but no change in Km (approximately 5 microM), suggesting that the cysteine residue is not involved in substrate binding . Its replacement by arginine possibly causes a conformational change in the active center . Like the wild-type enzyme, this mutant is heat stable and forms a tetramer . The susceptibility to proteolysis of C82R, however, is markedly increased in vitro compared with the wild-type protein . We have also observed a decrease in the expression levels of C82R protein in transfected mammalian cells, which could be due to proteolytic instability . The 18-amino acid-truncated mutant GLu-87--> termination could not be completely purified and characterized due to minute levels of expression and its extremely low solubility as a fusion protein . No dehydratase activity was detected in crude extracts from transformed bacteria or transfected mammalian cells . Considering the decrease in specific activity and stability of the mutants, we conclude that the patient probably has less than 10% residual dehydratase activity, which could be responsible for the mild hyperphenylalaninemia and the high 7-biopterin levels.

Experientia, 1995 Dec 18, 51(12), 1175 - 88
Cell adhesion in the life cycle of Dictyostelium; Bozzaro S et al.; Three forms of cell adhesion determine the life cycle of Dictyostelium: i) adhesion of bacteria to the surface of the growing amoebae, as the prerequisite for phagocytosis; ii) cell-substrate adhesion, necessary for both locomotion of the amoebae and migration of the slug; iii) cell-cell adhesion, essential for transition from the unicellular to the multicellular stage . Intercellular adhesion has received the most attention, and fruitful approaches have been developed over the past 25 years to identify, purify and characterize cell adhesion molecules . The csA glycoprotein, in particular, which mediates adhesion during the aggregation stage, is one of the best defined cell adhesion molecules . The molecular components involved in phagocytosis and cell-substratum adhesion are less well understood, but the basis has been laid for a systematic investigation of both topics in the near future.

Experientia, 1995 Dec 18, 51(12), 1124 - 34
PSF and CMF, autocrine factors that regulate gene expression during growth and early development of Dictyostelium; Clarke M et al.; Throughout growth and development, Dictyostelium cells secrete autocrine factors that accumulate in proportion to cell density . At sufficient concentration, these factors cause changes in gene expression . Vegetative Dictyostelium cells continuously secrete prestarvation factor (PSF) . The bacteria upon which the cells feed inhibit their response to PSF, allowing the cells to monitor their own density in relation to that of their food supply . At high PSF/bacteria ratios, which occur during late exponential growth, PSF induces the expression of several genes whose products are needed for cell aggregation . When the food supply has been depleted, PSF production declines, and a second density-sensing pathway is activated . Starving cells secrete conditioned medium factor (CMF), a glycoprotein of Mr 80 kDa that is essential for the development of differentiated cell types . Antisense mutagenesis has shown that cells lacking CMF cannot aggregate, and preliminary data suggest that CMF regulates cAMP signal transduction . Calculations indicate that a mechanism of simultaneously secreting and recognizing a signal molecule, as used by Dictyostelium to monitor cell density, could also be used to determine the total number of cells in a tissue.

FEMS Microbiol Lett, 1995 Dec 15, 134(2-3), 279 - 85
Genomic heterogeneity in Chlorobium limicola: chromosomic and plasmidic differences among strains; Mendez-Alvarez S et al.; Chromosome analysis by pulsed-field gel electrophoresis shows a high level of genetic heterogeneity between the two subspecies of the green sulfur bacteria Chlorobium limicola analysed: C . limicola and C . limicola f . s . thiosulfatophilum . Currently, they are differentiated only by the ability to utilize thiosulfate as photosynthetic electron donor, and by their %G + C content (51% and 58.1%, respectively) . However, the capacity to utilize thiosulfate as photosynthetic electron donor does not appear to be a useful criterion to differentiate between some strains of this species, because this ability is encoded by plasmids that are different depending on the thiosulfatophilum strain analysed . In contrast, this study reveals that the comparison of chromosomal restriction patterns is very useful as an additional aid for the differentiation and identification of C . limicola strains.

J Biol Chem, 1995 Dec 15, 270(50), 29640 - 3
Human ADP-ribosylation factor-activated phosphatidylcholine-specific phospholipase D defines a new and highly conserved gene family; Hammond SM et al.; Activation of phosphatidylcholine-specific phospholipase D (PLD) has been implicated as a critical step in numerous cellular pathways, including signal transduction, membrane trafficking, and the regulation of mitosis . We report here the identification of the first human PLD cDNA, which defines a new and highly conserved gene family . Characterization of recombinant human PLD1 reveals that it is membrane-associated, selective for phosphatidylcholine, stimulated by phosphatidylinositol 4,5-bisphosphate, activated by the monomeric G-protein ADP-ribosylation factor-1, and inhibited by oleate . PLD1 likely encodes the gene product responsible for the most widely studied endogenous PLD activity.

J Immunol, 1995 Dec 15, 155(12), 5760 - 8
Clearance pathways of soluble immune complexes in the pig . Insights into the adaptive nature of antigen clearance in humans; Davies KA et al.; Efficient delivery of immune complexes (ICs) to the mononuclear phagocytic system, and subsequent IC processing, may prevent their potentially harmful effects in other tissues and may also be important in the development of humoral immune responses . In mice, rabbits, and primates, the liver and spleen are the main sites of IC clearance . It has been demonstrated previously that the pulmonary capillaries in the pig are lined with macrophages and that certain particulates, including bacteria, localize to this organ . In this study, we used gamma scintigraphy to explore the sites and kinetics of clearance of soluble IC comprising 123I-labeled hepatitis B surface Ag (HBsAg):porcine anti-HBsAg in the Large White pig . At t = 10 min after i.v . injection, 43 +/- 5% (mean +/- SE) IC localized in the lungs, and 36 +/- 6% counts in the liver . At t = 85 min, values were: lungs, 15 +/- 4% and liver, 29 +/- 2% . Findings were similar following intraarterial injection . Complement depletion resulted in more rapid initial IC clearance (t1/2 = 5 min), reduced lung uptake (23 +/- 3% at 10 min), and impaired IC catabolism . In normal animals, 5 to 7% injected IC bound to PBMCs, but no E binding was seen . A fall in PBMC numbers (46 to 59% of baseline), was observed following IC injection . These findings contrast with our previous observations using analogous IC in humans, in which we did not observe any change in peripheral blood leukocyte counts consequent upon complex processing, suggesting that in humans, Es may function as a buffering system for complement-bearing IC in the circulation, preventing their interaction with leukocytes bearing complement and FcR, and the potential activation of these cells.

J Am Vet Med Assoc, 1995 Dec 15, 207(12), 1618 - 21
Epizootic of Mycobacterium bovis in a zoologic park; Stetter MD et al.; An epizootic of Mycobacterium bovis in a zoologic park resulted in the death of 4 southern white rhinoceroses and 2 colobus monkeys . Zoo personnel were detected that had positive intradermal tuberculin skin test results after exposure to mycobacterial-infected animals . On the basis of DNA fingerprinting, all 3 mycobacterial isolates (from 1 rhinoceros and 2 monkeys) were determined to be genetically similar and probably originated from the same source . The 3 animals (1 rhinoceros and 2 colobus monkeys) that had confirmed infections lived in separate, but adjacent, areas . Aerosolization of bacteria during routine cleaning was believed to have contributed to the unusual distance between infected animals . Tuberculosis has reemerged as a major disease problem in human and veterinary medicine.

Biochemistry, 1995 Dec 12, 34(49), 16004 - 12
Tyrosine 147 of cytochrome b is required for efficient electron transfer at the ubihydroquinone oxidase site (Qo) of the cytochrome bc1 complex; Saribas AS et al.; In Rhodobacter capsulatus, tyrosine (Y) 147 is a highly conserved residue of the cyt b subunit of the bc1 complex . It is located in the vicinity of residues altered in spontaneous inhibitor resistant mutants that affect the ubihydroquinone oxidase (Qo) site of this enzyme . In this work, Y147 was substituted with phenylalanine (F), valine (V), serine (S), and alanine (A) using site-directed mutagenesis in an effort to investigate its specific role in the Qo site . Of the four mutants obtained, Y147S and Y147A exhibited very low ubihydroquinone:cyt c reductase activities and were unable to support photosynthetic growth (Ps) while Y147F and Y147V were Ps+ . In all mutants, no changes in the redox midpoint potentials (Em7) of the cyt bH and cyt bL, the occupancy of the Qo site by Q/QH2, and the flash-induced reverse electron transfer kinetics from Qi to cyt bH were observed . On the other hand, rates of electron transfer from Qo to cyt bH were mildly reduced (2-3-fold) in Y147F and V but dramatically decreased (about 20-fold) in Y147A and S, localizing the defect to the Qo site . Thus, Y147A and S are members of a novel class of Qo site mutants that affect the Qo site catalysis without perturbing the accessibility or binding of the substrate . Additional insight to the role of Y147 on ubihydroquinone oxidation was gained by analyzing the Ps+ revertants of these mutants . Two pseudorevertants contained a second mutation {isoleucine (I) or valine (V)} at the highly conserved M154 position, six residues away from Y147.(ABSTRACT TRUNCATED AT 250 WORDS)

J Mol Biol, 1995 Dec 8, 254(4), 595 - 607
Mutations in the gene encoding the 34 kDa subunit of yeast replication protein A cause defective S phase progression; Santocanale C et al.; The in vivo function of the 34 kDa subunit of yeast replication protein A (RPA), encoded by the RFA2 gene, has been studied by analyzing the effect of Rpa34 depletion and by producing and characterizing rfa2 temperature-sensitive mutants . We show that unbalanced stoichiometry of the RPA subunits does not affect cell growth and cell cycle progression until the level of Rpa34 becomes rate-limiting, at which point cells arrest with a late S/G2 DNA content . Rpa34 is involved in DNA replication in vivo, since rfa2 ts mutants are defective in S phase progression and ARS plasmid stability, and rfa2 pol1 double mutants are non-viable . Moreover, when shifted to the restrictive temperature, about 50% of the rfa2 mutant cells rapidly die while traversing the S phase and the surviving cells arrest in late S/G2 at the RAD9 checkpoint . Finally, rfa2 mutant cells have a mutator and hyper-recombination phenotype and are more sensitive to hydroxyurea and methyl-methane-sulfonate than wild-type cells.

MMWR Morb Mortal Wkly Rep, 1995 Dec 8, 44(48), 892 - 3, 899-900
Unexplained severe illness possibly associated with consumption of Kombucha tea--Iowa, 1995; Outbreak of hepatitis A in a college traced to contaminated water reservoir in cafeteria; Division of Epidemiology, Ministry of Public Health, Nonthaburi, ThailandA sharp but short outbreak of hepatitis A occurred in a college during September and October 1992 . The epidemic pattern suggested a common source . The attack rate of clinically recognizable hepatitis A was 8% all cases were HAV IgM positive . Among 31 students with minor symptoms but without jaundice 8 (26%) were also HAV IgM positive, as were 8 (10%) of 77 totally asymptomatic students tested . A case control study of eating and drinking habits of the students showed no other significant differences other than that 45 of 56 cases and 18 of 34 controls interviewed had filled their water glasses by dipping them in a overflow water reservoir . This gives an odds ratio of 3.8 . The reservoir was heavily contaminated with coliform bacteria and the residual chlorine was at lower than standard concentration, whereas other water resources were clean . It is suggested that the reservoir had been contaminated with hepatitis A virus by somebody with fecally contaminated hands a couple of weeks prior to the beginning of the outbreak.

Cell Growth Differ, 1995 Dec, 6(12), 1495 - 503
The LAZ3/BCL6 oncogene encodes a sequence-specific transcriptional inhibitor: a novel function for the BTB/POZ domain as an autonomous repressing domain; Deweindt C et al.; Rearrangements and mutations of the LAZ3/BCL6 gene are the most frequent events associated with diffuse large-cell lymphoma, a particular class of non-Hodgkin's lymphomas . This gene encodes a putative regulatory protein with six COOH-terminal Kruppel-like zinc fingers and a NH2-terminal hydrophobic region, the so-called BTB/POZ domain, which mediates homo- as well as heterotypic interactions in other related proteins . Recently, a consensus binding sequence has been defined using the isolated LAZ3/BCL6 zinc finger region produced in bacteria . To understand the normal and oncogenic functions of LAZ3/BCL6, we examined its properties as a transcription factor . We thus demonstrated that its full-length product binds to the same consensus sequence, although the BTB/POZ domain decreases this activity, at least in vitro . In transient transfection experiments, the LAZ3/BCL6 protein exerts a repressive effect, both as a wild-type protein on its own target sequence and as a GAL-4 fusion protein . Furthermore, our results indicate that the BTB/POZ domain plays a prominent role in the mediation of this activity . Indeed, on the LAZ3/BCL6 cognate sequence, deletion of the BTB/POZ domain diminishes the repressive function . Conversely, as a GAL-4 chimera, the isolated LAZ3/BCL6 BTB/POZ domain appears nearly as efficient as the entire protein at inducing transcriptional repression . Taken together, these findings demonstrate that the LAZ3/BCL6 is a sequence-specific transcriptional repressor and point to a novel function for the BTB/POZ region, at least in LAZ3/BCL6, as an autonomous transcriptional inhibitory domain.

Differentiation, 1995 Dec, 59(5), 289 - 97
Cell-density-dependent repression of discoidin in Dictyostelium discoideum; Wetterauer BW et al.; When Dictyostelium discoideum cells are grown on bacteria, their natural food source, the discoidin genes are induced by cell-density-sensing factors before the food supply is exhausted {11, 18}, and expression increases continuously thereafter . This regulation pattern is changed when cells are grown in axenic medium: the discoidins are induced at a considerably lower cell density and are no longer expressed in stationary phase {13} . We have investigated this phenomenon further and show that repression begins when cells are still in exponential growth . It occurs at the level of transcription and involves an element of the discoidin I gamma promoter for which no function has previously been described . Since the effect of high cell density can be mimicked by conditioned medium, it appears that the repression is due to an extracellular signal . This signal is neither ammonia, nor folate, nor cAMP, the known repressors of discoidin expression.

Zentralbl Bakteriol, 1995 Dec, 283(2), 145 - 53
Diagnosis of catheter-related infections; Geiss HK; Catheter-related infections (CRI) are a major cause of febrile episodes in hospitalized patients . Additionally, approximately 40% of primary infections in intensive care patients are directly related to central venous catheters . Despite the clinical significance of CRI diagnostic procedures are still under debate . Clinical diagnosis which includes systemic signs of infection and suppuration at the catheter entry site is altogether a rare event . Therefore, most cases are still diagnosed by laboratory methods . Although the semiquantitative roll-plate technique is widely used and frequently regarded as gold standard, the disadvantages of a post-hoc diagnosis are obvious . In-situ techniques which leave the suspected catheter in place include differential blood cultures, skin and hub cultures and a new method of microscopic screening of blood drawn through the inflicted catheter . However, until now the true value of all these methods still lack unanimous acceptance . Further research is necessary to close the gap between clinical expectations and laboratory results.

Mol Microbiol, 1995 Dec, 18(5), 903 - 12
Control of P1 plasmid replication by iterons; Abeles AL et al.; The incA locus of plasmid P1 controls plasmid copy number by inhibiting the replication origin, oriR . Both loci contain repeat sequences (iterons) that bind the P1 RepA protein . Regulation appears to occur by contact of incA and oriR loci of daughter plasmids mediated by RepA-bound iterons . Synthetic incA iteron arrays were constructed with altered numbers, sequences or spacing of iterons . Using these in in vitro and in vivo assays, we examined two models: (i) that the origin and incA loci form a stable 1:1 complex in which multiple iterons of each locus are paired with those of the other, and (ii) that individual incA iterons act as freely diffusing nucleoprotein units that contact origin iterons in a random and dynamic fashion . The data presented here strongly favour the latter case . The origin, with its five iterons, acts as a target but not as an effector of regulation . We present a model for replication control based on random, dynamic contacts between incA iterons and the origin . This system would display randomness with respect to choice of templates and timing of initiation if multiple replicon copies were present, but would tend to act in a machine-like fashion in concert with the cell cycle if just two copies were present in a dividing cell.

Nihon Kyobu Shikkan Gakkai Zasshi, 1995 Dec, 33(12), 1392 - 1400
{Effect of clarithromycin on symptoms and mucociliary transport in patients with sino-bronchial syndrome}; Nishi K et al.; The effect of clarithromycin on symptoms and on mucociliary transport (as assessed by the saccharin test) were studied in 32 patients with sino-bronchial syndrome . Before treatment with clarithromycin, the nasal clearance time was significantly longer in these patients (70.3 +/- 64.7 min, mean +/- SD) than in control subjects (11.9 +/- 5.3 min, p < 0.001) . By the end of 4 weeks of treatment with oral clarithromycin (400 mg/day), nasal clearance time in the patients had improved significantly (30.4 +/- 39.5 min, p < 0.001) . Before clarithromycin therapy, bacteria were found in cultures of sputum from 15 patients . After clarithromycin therapy, bacteria were found in cultures of sputum from only 3 of those 15 patients . Cough frequency, volume of sputum, and dyspnea on exertion were significantly improved by clarithromycin therapy . These findings suggest that mucociliary transport is abnormal in patients with sino-bronchial syndrome, and that clarithromycin can be clinically useful in these patients.

Trends Microbiol, 1995 Dec, 3(12), 469 - 74
Vaccines for gonorrhea: where are we on the curve?
Blake MS, Wetzler LM.
Human antibodies that bind the gonococcal outer membrane modulate gonorrheal transmission and disease . The effects of antibody binding can favor either the host or the bacteria, and depend on the antigen involved . An effective gonococcal vaccine is feasible, but only by the careful selection and formulation of gonococcal antigens that elicit only host-protective antibodies.

Singapore Med J, 1995 Dec, 36(6), 619 - 20
Prolonged treatment with omeprazole does not improve the eradication rate of Helicobacter pylori infection--a short report {corrected}; Goh KL et al.; Omeprazole has been shown to have a suppressive effect on Helicobacter pylori . The aim of this study was to determine if prolonged treatment with omeprazole would result in a higher eradication rate than short course treatment . Twenty patients with endoscopy proven duodenal ulcers and unequivocal evidence of Helicobacter pylori (HP) infection based on culture, histology, urease test and Gram's stain of a fresh tissue smear were treated with omeprazole 40 mg om for 2-4 weeks . Following ulcer healing, patients received either maintenance omeprazole 20 mg om or placebo for up to one year . All 20 patients had healed ulcers following a 2-4 week course of omeprazole 40 mg om. . All were negative for HP at the end of treatment . Thirteen patients received short course therapy with omeprazole only, followed by placebo . On follow-up endoscopy at 3 months, only one of 13 (7.7%) had eradicated the bacteria . Seven patients received maintenance treatment with omeprazole 20mg om for one year . Following completion of treatment, patients were followed up at 1, 3 and 6 months . Only one of 7 (14.3%) patients had eradicated the infection on long term follow-up . The eradication rates of HP with both short and long course omeprazole monotherapy were low.

J Hepatol, 1995 Dec, 23(6), 727 - 33
Reticuloendothelial system function in acute liver injury induced by D-galactosamine; Kasravi FB et al.; AIMS/METHODS: Reticuloendothelial system function, as assessed by clearance of radiolabelled bacteria, was evaluated in acute liver injury induced by D-galactosamine in rats, and compared with that after 70% liver resection model . RESULTS: Reticuloendothelial system function was significantly impaired in both instances, but the extent and the pattern of reticuloendothelial system impairment differed in the two models . While the elimination rate of the radiolabelled bacteria (k-value) decreased in both the liver resection and D-galactosamine groups (19% and 52%, respectively), the corrected phagocytic index (alpha) increased in 70% liver resection (247%), indicatine increased activity among the remaining reticuloendothelial system cells of the liver . Estimation of subserosal organ blood flow showed decreased flow to the cecum and distal small intestine (correction of intesting) in both groups, whereas it was significantly increased (477%) in the remaining parts of the liver in the liver resection group . CONCLUSIONS: These findings show that reticuloendothelial system activity is deranged in both these groups, which may explain the increased occurrence of bacterial complications observed in corresponding clinical conditions.

Clin Infect Dis, 1995 Dec, 21(6), 1474 - 6
Vertebral osteomyelitis due to Roseomonas species: case report and review of the evaluation of vertebral osteomyelitis; Nahass RG et al.; We report what we believe is the first case of vertebral osteomyelitis caused by Roseomonas species . The diagnosis of vertebral osteomyelitis can be difficult . The case illustrates the importance of the establishment of an etiologic diagnosis in vertebral osteomyelitis . The features of Roseomonas species and the evaluation of cases of vertebral osteomyelitis are reviewed.

Curr Opin Struct Biol, 1995 Dec, 5(6), 758 - 66
Di-iron-carboxylate proteins; Nordlund P et al.; Di-iron centers bridged by carboxylate residues and oxide/hydroxide groups have so far been seen in four classes of proteins involved in dioxygen chemistry or phosphoryl transfer reactions . The dinuclear iron centers in these proteins are coordinated by histidines and additional carboxylate ligands . Recent structural data on some of these enzymes, combined with spectroscopic and kinetic data, can now serve as a base for detailed mechanistic suggestions . The di-iron sites in the major class of hydroxylase-oxidase enzymes, which contains ribonucleotide reductase and methane monooxygenase, show significant flexibility in the geometry of their coordination of three or more carboxylate groups . This flexibility, combined with a relatively low coordination number, and a buried environment suitable for reactive oxygen chemistry, explains their efficient harnessing of the oxidation power of molecular oxygen.

Vet Microbiol, 1995 Dec, 47(3-4), 245 - 56
Chlamydia psittaci in turkeys: pathogenesis of infections in avian serovars A, B and D; Vanrompay D et al.; At 7 days of age, 4 groups, each of twenty specific pathogen free turkeys kept in isolation units were inoculated by aerosol with the Texas Turkey strain (avian Chlamydia psittaci serovar D), strain 92/1293 (avian Chlamydia psittaci serovar D), strain 84/55 (avian Chlamydia psittaci serovar A) or strain 89/1326 (avian Chlamydia psittaci serovar B) . A fifth group of 4 specific pathogen free turkeys were sham inoculated controls . At daily intervals for 10 days and then twice weekly up to 34 days post infection, one bird in each group was killed and the target tissues and cells for replication and the sequence of events of serovar A, B and D infections was examined . In these turkeys, the primary site of replication was the respiratory tract . Chlamydial replication could be detected in the respiratory tract on day 1 post inoculation (p.i.) for group A, on day 3 p.i . for group B and on day 1 to 2 p.i . for groups D1 and D2 . Subsequently, there was chlamydaemia and localisation in the digestive tract, in one or more parenchymatous organs, in the pericardium and in the conjunctivae . Specific immunoperoxidase staining revealed chamydiae in these organs in epithelial cells and in monomorphonuclear cells in all infected groups . The monomorphonuclear cells were identified as macrophages by double immunofluorescence staining . Chlamydiae were present in the same tissues for serovars A and D, but could not be demonstrated in proventriculus, duodenum, pancreas, ovaries and testes for serovar B . Furthermore, the intensity of replication was similar for all serovars . However, for serovar B in comparison with the other serovars, the bacteria appeared in most tissues 1 to 6 days later and the maximal replication in these tissues occurred 3 to 4 days later.

Vet Immunol Immunopathol, 1995 Dec, 49(3), 229 - 39
Effect of passively administered immunoglobulin G on the colonization and clearance of Bordetella avium in turkeys; Suresh P et al.; This study was conducted to detect the effect of parenterally administered immunoglobulin isotype G (IgG) on the colonization and clearance of Bordetella avium at the tracheal surface in young turkeys . In two separate experiments, 3-week-old turkeys were infected with B . avium either after or before IgG administration . Comparisons were made between a control group which received an irrelevant IgG (specific for keyhole limpet hemocyanin {KLH}) and the experimental group which received a B . avium-specific IgG . When given before the bacteria, IgG reduced the numbers of colony-forming units (CFUs) in the trachea . As a supplement to non-specific respiratory defense mechanisms, B . avium-specific IgG also appears to inhibit colonization of the tracheal mucosa . In a second experiment designed to study the role of IgG in bacterial clearance, administration of B . avium-specific IgG after bacterial inoculation significantly reduced the number of CFUs on the tracheal surface . These studies support the role of B . avium-specific IgG in resistance to and recovery from B . avium infection.

Ann Trop Med Parasitol, 1995 Dec, 89 Suppl 1, 83 - 8
Vaccines against leishmaniasis; Modabber F; Unlike some other parasites, Leishmania can be grown in cell-free media with ease . This simple cultivation and the use of killed parasites as skin-test antigens (leishmanin) for diagnosis in humans during the past several decades have prompted scientists to try using the killed parasites, with or without adjuvant, as vaccines or for immunotherapy . In addition, different recombinant molecules, either parasite fractions or genetically engineered organisms (i.e . Leishmania made avirulent by removing specific genes, or bacteria carrying and expressing leishmanial genes), are being investigated as potential future vaccines against leishmaniasis . The 'first-generation' vaccines, composed of killed parasites with or without adjuvant, have been derived using an empirical approach . The 'second-generation' vaccines have been genetically constructed, using a more rational approach . At present, the first-generation vaccines are at various stages of Phase I (safety), II (reactivity) or III (efficacy) trials in humans . Results are expected in 1-2 years . The second-generation vaccines are, however, only in a preclinical state and are not expected to reach clinical trials for at least 3 years . The Special Programme for Research and Training in Tropical Diseases (TDR) is actively involved in most clinical trials of the first-generation vaccines and supports many of the second-generation candidates . In the present article, the advantages and disadvantages of each approach to vaccine development are discussed and the progress being made is briefly reviewed.

Eur Heart J, 1995 Dec, 16 Suppl O, 36 - 41
The epidemiology of infectious myocarditis, lymphocytic myocarditis and dilated cardiomyopathy; Friman G et al.; Infectious myocarditis is a common condition which often passes unrecognized, and the true incidence is thus unknown . Lymphocytic myocarditis has been recorded in 1.06% of 12,747 unselected routine autopsies performed over a 10-year period . Dilated cardiomyopathy (DCM) has an estimated frequency of 7.5-10% per 100,000 inhabitants per year . Overall, the enteroviruses, and particularly the Coxsackie-B viruses, predominate among viruses as the cause of myocarditis . As new molecular biological techniques have become available, the cytomegaloviruses (CMV) seem to have emerged as a more common cause of myocarditis than was previously recognized . Among the bacterial myocarditides, diphtheric myocarditis has become a serious threat in Russia and adjacent states during the 1990s . Among newly identified bacteria, Borrelia burgdorferi infection is accompanied by cardiac involvement in 1-8% of cases, where myocarditis with conduction disturbances is the most prominent feature . Chlamydia pneumoniae may be associated with myocarditis and sudden unexpected death . In AIDS, myocarditis with variable aetiology occurs in up to 50% of patients, although asymptomatic in most cases . In lymphocytic myocarditis and DCM, enteroviral-specific nucleotide sequences have been detected in about 30% of patients, and CMV-specific nucleotide sequences in 14% . Borrelia burgdorferi may occasionally be implicated in DCM . In this contribution we focus also on sudden unexpected death (SUD) in young athletes, since, in Sweden, an increased frequency of SUD has recently been observed in young orienteers and myocarditis was a common feature.

Eur J Clin Microbiol Infect Dis, 1995 Dec, 14(12), 1070 - 5
Role of immunoglobulin G subclasses in Q fever; Camacho MT et al.; The progression of Q fever to either acute or chronic disease has been attributed both to biological characteristics of the bacteria and to the host immune response . In order to determine whether a specific immunoglobulin G (IgG) subclass distribution could play a diagnostic or prognostic role in Q fever, IgG subclass levels were measured in patients with acute or chronic disease . It was observed that (i) IgG1 and IgG3 levels were elevated in patients with chronic Q fever compared to patients with acute disease or normal controls; (ii) variations over time reflected inverse complementary relationships of subclass levels, such as between IgG1 and IgG3 compared with IgG2 and IgG4, or an inverse relationship between IgG1 and IgG2; (iii) variations in IgG2 and IgG3 total subclass levels during follow-up of patients with chronic Q fever showed a decrease in IgG2 with a concomitant increase in IgG3 two years from disease onset . These findings indicate that measurements of IgG subclasses may be a simple, additional tool useful in the diagnosis of Q fever . This data raises the question of an unusual immunoregulatory mechanism in Q fever that is implicated in the presentation of the clinical disease.

Int J Lepr Other Mycobact Dis, 1995 Dec, 63(4), 518 - 28
CD4+ T-cell responses to recombinant hsp65 and hsp18 of M . leprae and their trypsin-digested fragments in leprosy: diversity in HLA-DR restriction; Mitra DK et al.; Mycobacterium leprae heat-shock proteins hsp65 and hsp18 have received immense attention as major T-cell target antigens in leprosy . Both of these hsps and their tryptic fragments were characterized for their ability to stimulate CD4+ T cells derived from polar leprosy cases and healthy contacts . The optimal digestion of hsps with trypsin yielded four fragments of hsp65--TDB65-1 (24 kDa), TDB65-2 (18 kDa), TDB65-3 (17 kDa), TDB65-4 (14 kDa)-- and three of hsp18--TDB18-1 (10 kDa), TDB18-2 (5 kDa), TDB18-3 (3 kDa) . While all of these tryptic fragments and undigested hsps triggered CD4+ T cells from tuberculoid (TT) leprosy patients and healthy contacts (SI > 2), only two fragments--TDB65-2 and TDB18-3--were found to be stimulatory in anergic lepromatous (LL) leprosy patients (SI = 5.27 and 3.0, respectively) . Blocking studies using allele-specific anti-DR monoclonal antibodies revealed multiple HLA-Dr restriction, with DR2 providing the strongest restriction in both TT as well as LL leprosy . These findings indicate that M . leprae hsps and their trypsin-digested fragments are promiscuous and recognizable in the context of diverse HLA alleles, of which DR2 is the most efficient restriction element . The 18-kDa fragment of hsp65 and the 3-kDa fragment of hsp18 are the most versatile fragments that could elicit in vitro proliferation in both polar forms of leprosy.

Lepr Rev, 1995 Dec, 66(4), 287 - 95
Extended studies on the viability of Mycobacterium leprae outside the human body; Desikan KV et al.; Very little is known in leprosy regarding the transmission of the infection from the source to the susceptible host . One of the important factors which governs the transmission of the disease is the viability of Mycobacterium leprae outside the human body . In this study M . leprae obtained from untreated patients have been subjected to several adverse conditions . Their viability was verified by their multiplication in the footpads of normal mice . After drying in the shade the organisms were viable up to 5 months . On wet soil, they remained alive for 46 days . Kept in saline at room temperature, the organisms lived for 60 days . Surprisingly on exposure to direct sunlight for 3 hours a day the bacteria survived for 7 days . On refrigeration at 4 degrees C, the bacteria could be preserved for 60 days . On the other hand, keeping at -70 degrees C, the bacteria could be maintained in a living condition for only 28 days . On exposure to antiseptics like Savlon (R) and alcohol, the bacteria were rapidly killed . These results indicate the survival outside the human body of M . leprae under different environmental conditions in India where the disease is endemic . Transmission of infection by indirect contact and occurrence of new cases in the absences of any known source, are consistent with M . leprae being viable outside the human body for varying periods of time . The findings could also be pointers to understand the epidemiology of leprosy.

Plant Mol Biol, 1995 Dec, 29(6), 1223 - 33
Molecular characterization of glyoxalase-I from a higher plant; upregulation by stress; Espartero J et al.; A cDNA, GLX1, encoding glyoxalase-I was isolated by differential screening of salt-induced genes in tomato . Glyoxalases-I and -II are ubiquitous enzymes whose functions are not clearly understood . They may serve to detoxify methylglyoxal produced from triosephosphates in all cells . The protein encoded by GLX1 shared 49.4% and 58.5% identity with glyoxalase-I isolated from bacteria and human, respectively . Furthermore, yeast cells expressing GLX1 showed a glyoxalase-I specific activity 20-fold higher than non-transformed cells . Both GLX1 mRNA and glyoxalase-I polypeptide levels increased 2- to 3-fold in roots, stems and leaves of plants treated with either NaCl, mannitol, or abscisic acid . Immunohistochemical localization indicated that glyoxalase-I was expressed in all cell types, with preferential accumulation in phloem sieve elements . This expression pattern was not appreciably altered by salt-stress . We suggest that the increased expression of glyoxalase-I may be linked to a higher demand for ATP generation and to enhanced glycolysis in salt-stressed plants.

N Y State Dent J, 1995 Dec, 61(10), 22 - 8
Doctor, would you drink water from your dental unit?
Prevost AP, Robert M, Charland R, Barbeau J.
Contamination of dental unit water lines is not new to dentistry, but this problem takes on a new dimension when considering immuno-deficient patients and existing infection-control measures . This study identifies the bacteria involved in the contamination process, estimates the contamination levels and reviews the methods that may be used to control the contamination.

J Endod, 1995 Dec, 21(12), 613 - 6
Anaerobic tissue-dissolving abilities of calcium hydroxide and sodium hypochlorite; Yang SF et al.; Closed root canals likely have an oxygen-free environment; most bacteria in canals are anaerobic . These bacteria and other debris are difficult to remove . Unknown is tissue dissolution with chemicals under these anaerobic conditions . This study evaluated and compared dissolving properties of calcium hydroxide (Ca(OH)2) and sodium hypochlorite (NaOCl) on bovine pulp tissue in aerobic and anaerobic environments . Sixty bovine pulp specimens were dried, then randomly divided into six groups . Groups A and B were immersed in Ca(OH)2 + water solution, whereas group C and D were in 2.5% NaOCl . Groups E and F (controls) specimens were placed in distilled water . Groups A, C, and E were incubated anaerobically, and groups B, D, and F were incubated under regular atmospheric conditions, all for 7 days . Percentages of weight loss were compared between groups . Results showed the following: (a) both chemicals partially dissolved pulp tissue, (b) anaerobic environment did not alter tissue-dissolving properties of Ca(OH)2 or NaOCl, and (c) Ca(OH)2 and NaOCl were equal and more effective than water.

Trends Biotechnol, 1995 Dec, 13(12), 497 - 500
Discovering the intelligence in molecular biology; Uberbacher E; The Third International Conference on Intelligent Systems in Molecular Biology was truly an outstanding event . Computational methods in molecular biology have reached a new level of maturity and utility, resulting in many high-impact applications . The success of this meeting bodes well for the rapid and continuing development of computational methods, intelligent systems and information-based approaches for the biosciences . The basic technology, originally most often applied to 'feasibility' problems, is now dealing effectively with the most difficult real-world problems . Significant progress has been made in understanding protein-structure information, structural classification, and how functional information and the relevant features of active-site geometry can be gleaned from structures by automated computational approaches . The value and limits of homology-based methods, and the ability to classify proteins by structure in the absence of homology, have reached a new level of sophistication . New methods for covariation analysis in the folding of large structures such as RNAs have shown remarkably good results, indicating the long-term potential to understand very complicated molecules and multimolecular complexes using computational means . Novel methods, such as HMMs, context-free grammars and the uses of mutual information theory, have taken center stage as highly valuable tools in our quest to represent and characterize biological information . A focus on creative uses of intelligent systems technologies and the trend toward biological application will undoubtedly continue and grow at the 1996 ISMB meeting in St Louis.

Biomaterials, 1995 Dec, 16(18), 1395 - 400
Physico-mechanical properties of poly (epsilon-caprolactone) for the construction of rumino-reticulum devices for grazing animals; Vandamme TF et al.; The solid-state degradation of poly(epsilon-caprolactone) in the rumen of fistulated cattle was investigated . The degradation process was studied by measurement of changes in weight loss, crystallinity, Young's modulus, molecular weight by size exclusion chromatography and by intrinsic viscosity . In vitro degradation studies were conducted at 39 degrees C in aqueous solutions with a pH and ionic strength as near as possible to those encountered in vivo . Such studies demonstrated that the poly (epsilon-caprolactone) degraded more rapidly in vivo than in vitro . In vivo, chain scission is associated with an increase in crystallinity . The faster degradation in vivo was attributed to fatty acids and bacteria that are present in the rumen, the first portion of the stomach of the grazing animals.

Exp Mycol, 1995 Dec, 19(4), 314 - 9
Osmotic effects on the polyamine pathway of Neurospora crassa; Davis RH et al.; In bacteria, mammals, and certain plants, the induction of the polyamine synthetic enzyme, ornithine decarboxylase (ODC), and the accumulation of its product, putrescine, follows osmotic manipulations of cells . In at least some of these cases, this response is indispensable for survival . We wished to determine whether the polyamine pathway of Neurospora crassa was regulated in response to hyper- or hypoosmotic conditions . Unlike ODC of most other classes of organisms, the N . crassa enzyme and the accumulation of putrescine appears to be relatively indifferent to these conditions, either during sudden transitions or in steady-state . We conclude that other mechanisms of osmotic adjustment or tolerance have evolved in N . crassa and perhaps other fungi that obviate the need for putrescine accumulation.

Immunology, 1995 Dec, 86(4), 519 - 24
Protection against tuberculosis by bone marrow cells expressing mycobacterial hsp65; Silva CL et al.; Although mice acquire only a slight degree of protection against tuberculosis by immunization with Mycobacterium leprae (M . leprae) hsp65 in incomplete Freund's adjuvant, protection is substantial following immunization by injection with J774 macrophage-like tumour cells that express the protein from the mycobacterial gene via a retroviral vector . We here took the same vector, used it to transfect the gene into normal murine bone marrow cells in vitro, and then used the transfected cells to reconstitute haematopoiesis in lethally irradiated mice . Bone marrow-cell clonal expansion and production of the protein in vivo resulted in specific delayed-type hypersensitivity and protection against challenge with Mycobacterium tuberculosis (M . tuberculosis) in about half of recipients . Counts of live bacteria in liver at 3 weeks were fivefold lower in delayed-type hypersensitivity (DTH)-positive than in DTH-negative mice . Other mice acquired neither DTH nor protection despite the presence of the protein in peripheral blood.

Plant Mol Biol, 1995 Dec, 29(5), 933 - 45
Light-dependent chlorophyll a biosynthesis upon chlL deletion in wild-type and photosystem I-less strains of the cyanobacterium Synechocystis sp . PCC 6803; Wu Q et al.; Part of the chlL gene encoding a component involved in light-independent protochlorophyllide reduction was deleted in wild type and in a photosystem I-less strain of Synechocystis sp . PCC 6803 . In resulting mutants, chlorophyll biosynthesis was fully light-dependent . When these mutants were propagated under light-activated heterotrophic growth conditions (in darkness except for 15 min of weak light a day) for several weeks, essentially no chlorophyll was detectable but protochlorophyllide accumulated . Upon return of the chlL- mutant cultures to continuous light, within the first 6 h chlorophyll was synthesized at the expense of protochlorophyllide at a rate independent of the presence of photosystem I . Chlorophyll biosynthesized during this time gave rise to a 685 nm fluorescence emission peak at 77 K in intact cells . This peak most likely originates from a component different from those known to be directly associated with photosystems II and I . Development of 695 and 725 nm peaks (indicative of intact photosystem II and photosystem I, respectively) required longer exposures to light . After 6 h of greening, the rate of chlorophyll synthesis slowed as protochlorophyllide was depleted . In the chlL- strain, greening occurred at the same rate at two different light intensities (5 and 50 microE m-2 s-1), indicating that also at low light intensity the amount of light is not rate-limiting for protochlorophyllide reduction . Thus, in this system the rate of chlorophyll biosynthesis is limited neither by biosynthesis of photosystems nor by the light-dependent protochlorophyllide reduction . We suggest the presence of a chlorophyll-binding 'chelator' protein (with 77 K fluorescence emission at 685 nm) that binds newly synthesized chlorophyll and that provides chlorophyll for newly synthesized photosynthetic reaction centers and antennae.

J Laryngol Otol, 1995 Dec, 109(12), 1168 - 75
Pharyngeal trauma in children--accidental and otherwise; Tostevin PM et al.; Pharyngeal perforation is an uncommon injury in children . Most reported cases to date have been secondary to instrumentation or penetrating wounds . Laceration to the pharyngeal wall may introduce air, secretions and bacteria into the parapharyngeal space and mediastinum and consequently has potentially life-threatening sequelae . The management of these injuries is controversial . We present a series of four children who suffered pharyngeal trauma, accidentally and otherwise, and discuss their management . We recommend a high index of suspicion of pharyngeal injury in all cases of oropharyngeal trauma and overnight admission to hospital for observation until an accurate diagnosis has been established . Non-accidental injury of the child must be seriously considered in all cases.

Eur J Biochem, 1995 Dec 1, 234(2), 592 - 7
Purification and properties of coenzyme F390 hydrolase from Methanobacterium thermoautotrophicum (strain Marburg); Vermeij P et al.; 8-Hydroxyadenylylated coenzyme F420 (coenzyme F390-A) is formed in methanogenic bacteria upon oxidative stress . After reinstatement of anaerobic conditions, coenzyme F390 is degraded into coenzyme F420 and AMP . The enzyme catalyzing the latter reaction, coenzyme F390 hydrolase, was purified to homogeneity from Methanobacterium thermoautotrophicum strain Marburg 355-fold to a specific activity of 12.1 mumol.min-1.mg protein-1 . The enzyme consisted of one polypeptide of approximately 27 kDa . Coenzyme F390 hydrolase displayed an apparent Km for coenzyme F390 of 40 microM . The enzyme required the presence of a reducing agent like dithiothreitol to become active . Activity could be manipulated by applying various ratios of reduced and oxidized dithiothreitol . Activation proceeded by a two-electron reduction, which indicates that one S-S bridge is involved the activation/inactivation of the enzyme . Dithiothreitol could be replaced by the methanogenic C1-carrier 2-mercaptoethanesulfonate (H-S-CoM), but not by N7-mercaptoheptanoyl-L-threonine phosphate (H-S-HTP) or other naturally occurring thiol-containing compounds . The addition of the heterodisulfide of H-S-CoM and H-S-HTP (CoM-S-S-HTP) diminished the stimulatory effect of H-S-CoM.

Clin Exp Immunol, 1995 Dec, 102(3), 456 - 61
Peripheral cell-mediated immune response to mycobacterial antigens in inflammatory bowel disease; Rowbotham DS et al.; A mycobacterial etiology has been proposed in Crohn's disease (CD) . We have sought evidence of increased or modified T lymphocyte immune responses to Mycobacterium tuberculosis and Myco, paratuberculosis in patients with CD (n = 13), compared with ulcerative colitis (UC; n = 17) and controls (n = 17) . Peripheral blood cells were cultured with phytohaemagglutinin (positive mitogen control), mycobacterial purified protein derivative (PPD) preparations, lysates, column fractions and whole, heat-killed bacteria . Responses of T cells and T cell subsets were assessed by expression of activation markers (CD25, CD69), coupled with blastogenesis assays (3H-thymidine uptake) and estimates of proliferation . Virtually all patients responded to Myco . paratuberculosis and Myco . tuberculosis antigens . There were no significant differences between patient groups, although there was a very high overall correlation (r = 0.95; P < 0.0001) between responses to the two mycobacterial species . Most of the activation and proliferative responses resided in the CD4+ (T helper) subset . Although up to 15% of CD8+ (suppressor/cytotoxic) cells also became activated, the CD8+ cells did not proliferate subsequently . Cells expressing the alternate gamma delta form of the T cell receptor (TCR gamma delta+) did not activate or proliferate in response to mycobacterial antigens . There were no differences in any of these parameters between patient groups . We conclude that there is no specific increase or alteration in cell-mediated anti-mycobacterial immunity in inflammatory bowel disease (IBD) . Thus our data do not support a mycobacterial etiopathology of Crohn's disease.

Curr Microbiol, 1995 Dec, 31(6), 377 - 81
Specific PCR detection and identification of Xylella fastidiosa strains causing citrus variegated chlorosis; Pooler MR et al.; By cloning and sequencing specific randomly amplified polymorphic DNA (RAPD) products, we have developed pairs of PCR primers that can be used to detect Xylella fastidiosa in general, and X . fastidiosa that cause citrus variegated chlorosis (CVC) specifically . We also identified a CVC-specific region of the X . fastidiosa genome that contains a 28-nucleotide insertion, and single base changes that distinguish CVC and grape X . fastidiosa strains . When using RAPD products to develop specific PCR primers, we found it most efficient to screen for size differences among RAPD products rather than presence/absence of a specific RAPD band.

J Bacteriol, 1995 Dec, 177(24), 7210 - 21
Interactive regulation of Azorhizobium nifA transcription via overlapping promoters; Loroch AI et al.; The Azorhizobium nifA promoter (PnifA) is positively regulated by two physiological signal transduction pathways, NtrBC, which signals anabolic N status, and FixLJK, which signals prevailing O2 status . Yet, PnifA response (gene product per unit time) to these two activating signals together is more than twice that of the summed, individual signals . In the absence of NIFA, a negative PnifA autoregulator, the fully induced PnifA response is more than 10-fold greater than that of summed, individual signals . Given this synergism, these two signal transduction pathways must interactively regulate PnifA activity . PnifA carries three cis-acting elements, an anaerobox, which presumably binds FIXK, a NIFAbox, which presumably binds NIFA itself, and a sigma 54 box, which presumably binds sigma 54 initiator, a subunit of RNA polymerase . For combinatorial analysis, single, double, and triple promoter mutations were constructed in these cis-acting elements, and PnifA activities were measured in six different trans-acting background, i.e., fixK, fixJ, nifA, ntrC, rpoF, and wild type . Under all physiological conditions studied, high-level PnifA activity required both FIXK in trans and the anaerobox element in cis . Surprisingly, because PnifA was hyperactive with a mutated sigma 54box, this cis-acting element mediates both negative and positive control . Because PnifA hyperactivity also required a wild-type upstream NIFAbox element, even in the absence of NIFA, a second upstream nifA transcription start superimposed on the NIFAbox element was hypothesized . When nifA mRNA 5' start points were mapped by primer extension, both a minor upstream transcript(s) starting 45 bp distal to the anaerobox and a major downstream transcript starting 10 bp distal to the sigma 54 box were observed . In Azorhizobium, RNA polymerase sigma 54 initiator subunits are encoded by a multigene family, which includes rpoF and rpoN genes . Because rpoF mutants show an Ntr+ phenotype, whereas rpoN mutants are Ntr-, multiple sigma 54 initiators are functionally distinct . Two independent rpoF mutants both show a tight Nif- phenotype . Moreover, rpoF product sigma 54F is absolutely required for high-level PnifA activity . In summary, the Azorhizobium nifA gene carries overlapping housekeeping-type and sigma 54-type promoters which interactively respond to different signals . Effectively, the upstream, housekeeping-type promoter responds to FIXK and positively regulates the downstream, sigma 54-type promoter . The downstream, sigma 54-type promoter responds to NTRC and negatively regulates the upstream, housekeeping-type promoter . In terms of transcript yield, the upstream, housekeeping-type promoter is therefore weak, and the downstream, sigma 54-type promoter is strong.

J Bacteriol, 1995 Dec, 177(24), 7041 - 9
In vitro recognition of the replication origin of pLS1 and of plasmids of the pLS1 family by the RepB initiator protein; Moscoso M et al.; Rolling-circle replication of plasmid pLS1 is initiated by the plasmid-encoded RepB protein, which has nicking-closing (site-specific DNA strand transferase) enzymatic activity . The leading-strand origin of pLS1 contains two regions, (i) the RepB-binding site, constituted by three directly repeated sequences (iterons or the bind region), and (ii) the sequence where RepB introduces the nick to initiate replication (the nic region) . A series of plasmids, belonging to the pLS1 family, show features similar to those of pLS1 and have DNA sequences homologous to the pLS1 nic region . In addition, they all share homologies at the level of their Rep proteins . However, the bind regions of these plasmids are, in general, not conserved . We tested the substrate specificity of purified RepB of pLS1 . The RepB protein has a temperature-dependent nicking-closing action on supercoiled pLS1, as well as on recombinant plasmid DNAs harboring the pLS1 nic region . The DNA strand transferase activity of pLS1-encoded RepB was also assayed on two plasmids of the pLS1 family, namely, pE194 and pFX2 . DNAs from both plasmids were relaxed by RepB, provided they had a proper degree of supercoiling; i.e., it was necessary to modulate the supercoiling of pE194 DNA to achieve RepB-mediated DNA relaxation . Single-stranded oligonucleotides containing the nic regions of various plasmids belonging to the pLS1 family, including those of pE194 and pFX2, were substrates for RepB . In vitro, the RepB protein does not need to bind to the iterons for its nicking-closing activity.

J Infect Dis, 1995 Dec, 172(6), 1598 - 601
Interaction with human immunodeficiency virus type 1 modulates innate effector functions of human monocytes; Zerlauth G et al.; The effect of human immunodeficiency virus (HIV) type 1 on human mononuclear phagocyte effector functions in response to infection with bacteria of the Mycobacterium avium-intracellular complex (MAC) was investigated . The results showed that interaction of HIV-1 or its constituents with CD4 expressed in the monocyte membrane led to substantial impairment of monocyte capacity to restrict the intracellular growth of MAC . This was accompanied by substantially decreased production of tumor necrosis factor-alpha by HIV-1-exposed and MAC-infected monocytes . However, productive HIV-1 infection of monocytes was not required to induce the observed effects . These studies suggest that HIV-1 may interfere with innate mononuclear phagocyte function . This may be of physiologic importance in the late stages of AIDS, when an impaired T cell immunity can no longer provide proper immune-activating signals, and may help to explain the undue susceptibility to MAC infections in these patients.

J Immunol, 1995 Dec 1, 155(11), 5343 - 51
Pulmonary surfactant protein A mediates enhanced phagocytosis of Mycobacterium tuberculosis by a direct interaction with human macrophages; Gaynor CD et al.; During initial infection with Mycobacterium tuberculosis, bacteria that reach the distal airspaces of the lung are phagocytosed by alveolar macrophages in the presence of pulmonary surfactant . Here we have examined the role of surfactant-associated protein A (SP-A) in phagocytosis of the virulent Erdman strain of M . tuberculosis by human monocyte-derived macrophages (MDMs) and human alveolar macrophages (HAMs) . Macrophage monolayers incubated with soluble SP-A from alveolar proteinosis patients (APP SP-A4) and recombinant rat SP-A (SP-Ahyp) demonstrated enhanced adherence of M . tuberculosis, 82 +/- 17% and 49 +/- 18%, respectively . Removal of SP-A from monolayers by washing before adding bacteria did not diminish the enhanced adherence . Fluorescence microscopy demonstrated that washed monolayers contained intracellular rather than surface-bound SP-A . These studies indicated a direct interaction between SP-A and the macrophage in mediating enhanced adherence of M . tuberculosis . Consistent with this interpretation, macrophage monolayers formed on human or rat SP-A (substrate SP-A) demonstrated enhanced adherence of M . tuberculosis to their apical surface (APP SP-A and native rat SP-A increased M . tuberculosis adherence by 102 +/- 16% and 102 +/- 25%, respectively) . Electron microscopy demonstrated increased numbers of phagocytosed bacteria in APP SP-A-treated MDM cross-sections . SP-A proteins devoid of carbohydrate failed to enhance M . tuberculosis adherence to macrophages . In contrast, heat-denatured APP SP-A enhanced adherence of bacteria equivalent to that of intact glycoprotein . Thus, the carbohydrate moieties of SP-A appear to be critical in the SP-A-macrophage interaction . Finally, mannan and anti-mannose receptor Ab completely inhibited the enhanced phagocytosis of M . tuberculosis observed with APP SP-A, providing evidence for up-regulation of macrophage mannose receptor activity . These studies implicate SP-A as an important modulator of alveolar macrophage function that results in an enhanced potential for M . tuberculosis to gain access to its intracellular niche.

J Immunol, 1995 Dec 1, 155(11), 5273 - 9
Nuclear factor-IL6 activates the human IL-4 promoter in T cells; Davydov IV et al.; Positive regulatory element I (PRE-I) is a strong enhancer element essential for expression of the human IL-4 gene . To identify transcription factors binding to PRE-I, we screened a cDNA expression library from Jurkat T cells and isolated a cDNA encoding nuclear factor (NF)-IL6 (also known as C/EBP beta) . NF-IL6 mRNA was found in human Jurkat T cells and in the mouse Th2 clone D10, but not in Th1 clone 29 . rNF-IL6 expressed in bacteria was shown to specifically bind to PRE-I . PRE-I forms multiple DNA-protein complexes with nuclear extracts from Jurkat cells . Some of these complexes were demonstrated to contain NF-IL6 by using anti-C/EBP beta Abs . Overexpression of NF-IL6 enhanced expression of the chloramphenicol acetyl transferase reporter gene linked to the PRE-I-thymidine kinase or the human IL-4 promoter more than 10-fold in Jurkat cells . Promoter deletion studies revealed two additional NF-IL6 binding sites located at positions -44 to -36 (C/EBP proximal) and -87 to -79 (C/EBP medial), respectively . Our results demonstrate that NF-IL6 is involved in transcriptional activation of the human IL-4 promoter in T cells.

J Bacteriol, 1995 Dec, 177(23), 6825 - 31
Identification and nucleotide sequences of mxaA, mxaC, mxaK, mxaL, and mxaD genes from Methylobacterium extorquens AM1; Morris CJ et al.; The DNA sequence for a 4.4-kb HindIII-XhoI Methylobacterium extorquens AM1 DNA fragment that is known to contain three genes (mxaAKL) involved in incorporation of calcium into methanol dehydrogenase (I . W . Richardson and C . Anthony, Biochem . J . 287:709-7115, 1992) was determined . Five complete open reading frames and two partial open reading frames were found, suggesting that this region contains previously unidentified genes . A combination of sequence analysis, mutant complementation data, and gene expression studies showed that these genes correspond to mxaSACKLDorf1 . Of the three previously unidentified genes (mxaC, mxaD, and orf1), mutant complementation studies showed that mxaC is required for methanol oxidation, while the function of the other two genes is still unknown.

Infect Immun, 1995 Dec, 63(12), 4826 - 9
Isolation, cultivation, and partial characterization of the ELB agent associated with cat fleas; Radulovic S et al.; ELB rickettsiae from cat flea homogenates were recovered in tissue culture cells following sequential passage through laboratory rats and the yolk sacs of embryonated chicken eggs . Seven days after inoculation of ELB from the infected yolk sacs, Vero cells and L929 cells were observed to contain intracellular bacteria as demonstrated by Diff Quik and indirect immunofluorescence assay staining . The rickettsial and ELB identity of the cultured agent was confirmed by PCR detection of the 16S rRNA and citrate synthase genes and PCR-restriction fragment length polymorphism analysis of the 17-kDa conserved rickettsial antigen gene . The ELB rickettsiae induced plaques in Vero cells on day 11 postinfection . Rat anti-ELB serum reacted at 1:4,096 to cultured ELB and had lower reactivity to Rickettsia typhi Wilmington (1:1,024), Rickettsia akari Kaplan (1:512), and Rickettsia australis JC (1:64) . Spotted fever group polyclonal sera also exhibited lower reactivity to ELB than to the homologous antigen . Coomassie blue-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of the ELB isolate and two R . typhi strains were identical.

J Trauma, 1995 Dec, 39(6), 1123 - 8
Influence of reaming versus nonreaming in intramedullary nailing on local infection rate: experimental investigation in rabbits; Melcher GA et al.; The question of whether the impairment of the endosteal blood supply, which is induced by nailing with reaming of the medullary cavity, increases the risk of a postoperative infection cannot be conclusively answered by studying existing literature . The aim of this study was to investigate the effect of medullary reaming on the occurrence of local infection based on an infection model in the rabbit tibia (n = 44) . An infection rate of 50% was found after unreamed nailing, as opposed to an infection rate of 64% after medullary reaming . The number of bacteria observed after reaming was significantly higher than after nail insertion without previous reaming . The differing susceptibilities to infection as observed in this model are statistically significant (p < or = 0.05).

J Biol Chem, 1995 Dec 1, 270(48), 28938 - 45
Identification of two novel Dictyostelium discoideum cysteine proteinases that carry N-acetylglucosamine-1-P-modification; Souza GM et al.; Dictyostelium discoideum makes multiple developmentally regulated lysosomal cysteine proteinases . One of these, a lysosomal enzyme called proteinase I, contains a cluster of GlcNAc-alpha-1-P-Ser residues . We call this phosphoglycosylation . To study its function, a cDNA library from vegetative cells was screened, and two novel cysteine proteinase clones were characterized (cprD and cprE) . Each of them has highly conserved regions expected for cysteine proteinases, but unlike any other, each has a serine-rich domain containing three distinct motifs, poly-S, SGSQ, and SGSG . cprD and cprE cDNAs were overexpressed in Dictyostelium and the active enzymes identified . cprD codes for a protein of approximately 36 kDa (CP4), which is recognized by monoclonal antibodies against GlcNAc-1-P and fucose . cprE corresponds to a 29-kDa protein, which is recognized by antibodies against GlcNAc-1-P . mRNA for both enzymes is present in the vegetative phase and increases during growth on bacteria but decreases throughout development . When the formation of the fruiting body is complete the mRNA for both messages is detected again but in very low levels . Having cloned cDNAs for proteins that carry GlcNAc-1-P should allow us to probe the function of the carbohydrate in these putative lysosomal enzymes.

J Biol Chem, 1995 Dec 1, 270(48), 28897 - 902
Isolation of MEK5 and differential expression of alternatively spliced forms; English JM et al.; The prototype mitogen-activated protein (MAP) kinase module is a three-kinase cascade consisting of the MAP kinase, extracellular signal-regulated protein kinase (ERK) 1 or ERK2, the MAP/ERK kinase (MEK) MEK1 or MEK2, and the MEK kinase, Raf-1 or B-Raf . This and other MAP kinase modules are thought to be critical signal transducers in major cellular events including proliferation, differentiation, and stress responses . To identify novel mammalian MAP kinase modules, polymerase chain reaction was used to isolate a new MEK family member, MEK5, from the rat . MEK5 is more closely related to MEK1 and MEK2 than to the other known mammalian MEKs, MKK3 and MKK4 . MEK5 is thought to lie in an uncharacterized MAP kinase pathway, because MEK5 does not phosphorylate the ERK/MAP kinase family members ERK1, ERK2, ERK3, JNK/SAPK, or p38/HOG1, nor will Raf-1, c-Mos, or MEKK1 highly phosphorylate it . Alternative splicing results in a 50-kDa alpha and a 40-kDa beta isoform of MEK5 . MEK5 beta is ubiquitously distributed and primarily cytosolic . MEK5 alpha is expressed most highly in liver and brain and is particulate . The 23 amino acids encoded by the 5' exon in the larger alpha isoform are similar to a sequence found in certain proteins believed to associate with the actin cytoskeleton; this alternatively spliced modular domain may lead to the differential subcellular localization of MEK5 alpha.

Chest, 1995 Dec, 108(6), 1632 - 9
Reappraisal of distal diagnostic testing in the diagnosis of ICU-acquired pneumonia; Timsit JF et al.; BACKGROUND: The thresholds of the diagnostic procedures performed to diagnose ICU-acquired pneumonia (IAP) are either speculated or incompletely tested . PURPOSE: To evaluate the best threshold of protected specimen brush (PSB), plugged telescoping catheter (PTC), BAL culture (BAL C), and direct examination of cytocentrifugated lavage fluid (BAL D) to diagnose IAP . Each mechanically ventilated patient with suspected IAP underwent bronchoscopy successively with PSB, PTC, and BAL in the lung segment identified radiographically . POPULATION: One hundred twenty-two episodes of suspected IAP (occurring in 26% of all mechanically ventilated patients) were studied . Forty-five patients had definite IAP, and 58 had no IAP . Diagnosis was uncertain in 19 cases . RESULTS: Using the classic thresholds, sensitivity was 67% for PSB, 54% for PTC, 59% for BAL D, and 77% for BAL C . Specificity was 88% for PSB, 77% for PTC, 98% for BAL D, and 77% for BAL C . We used receiver operating characteristics methods to reappraise thresholds . Decreasing the thresholds to 500 cfu/mL for PSB, 10(2) cfu/mL for PTC, 2% cells containing bacteria for BAL D, 4 x 10(3) cfu/mL for BAL C increased the sensitivities (plus 14%, 23%, 25%, 10%, respectively) and moderately decreased the specificities (minus 4%, 9%, 2%, 4%, respectively) of the four examinations . The association of PSB with a 500 cfu/mL threshold and BAL D with a 2% threshold recovered all but one episode of pneumonia (SE 96 +/- 4%) with a 84 +/- 10% specificity . For a similar ICU population, these "best" thresholds increased negative predictive value with a minimal decrease of positive predictive value . They need to be confirmed in multiple ICU settings in prospective fashion.

Orig Life Evol Biosph, 1995 Dec, 25(6), 549 - 64
The phylogeny of tRNAs seems to confirm the predictions of the coevolution theory of the origin of the genetic code; Di Giulio M; An extensive analysis of the evolutionary relationships existing between transfer RNAs, performed using parsimony algorithms, is presented . After building up an estimate of the tRNA ancestral sequences, these sequences are then compared using certain methods . The results seem to suggest that the coevolution hypothesis (Wong, J.T., 1975, Proc . Natl . Acad . Sci . USA 72, 1909-1912) that sees the genetic code as a map of the biosynthetic relationships between amino acids is further supported by these results, as compared to the hypotheses that see the physicochemical properties of amino acids as the main adaptative theme that led to the structuring of the genetic code.

Am J Surg, 1995 Dec, 170(6), 665 - 9; discussion 669-70
Comparison of diagnostic specimens and methods to evaluate infected venous access ports; Whitman ED et al.; BACKGROUND: Implanted venous access port infection can be difficult to diagnose and treat . If device removal is necessary, confirming port infection is problematic . MATERIALS AND METHODS: Culture specimens from three sites, catheter tip (Tip), port pocket, and the material within the reservoir (Inside), were sent from ports removed for potential infection . The results of these cultures were compared to preremoval peripheral and central blood cultures . RESULTS: Forty-five ports were removed for suspected infection . Confirmed port infection was defined as positive culture(s) from one or more experimental specimen(s) . In 29 evaluable cases, the Inside specimens were completely predictive . Tip specimens were less accurate, even with a lower diagnostic threshold . In 7 of 19 confirmed infections, only the Inside culture was diagnostic . CONCLUSION: The most predictive culture specimen in a potentially infected port is the thrombotic material inside the reservoir.

Pediatrics, 1995 Dec, 96(6), 1137 - 42
Serologic responses to Bartonella and Afipia antigens in patients with cat scratch disease; Szelc-Kelly CM et al.; OBJECTIVE . To assess the serologic response to Afipia and Bartonella, previously named Rochalimaea, in patients with cat scratch disease (CSD) and a healthy control group . DESIGN . Prospective, controlled trial . SETTING: Referral clinic and hospitalized patients in a university medical center . PARTICIPANTS . Eighty patients with CSD and 57 healthy control subjects of similar age . MAIN OUTCOME MEASURES . The immune responses to Afipia felis and Bartonella henselae were evaluated by a newly developed enzyme-linked immunosorbent assay (ELISA) in patients with CSD and healthy control subjects . Responses to B henselae were also measured by indirect fluorescent antibody (IFA) tests . Antibody levels to Bartonella quintana were measured by ELISA and IFA in a limited number of patients and control subjects . RESULTS . Of the 80 patients with clinical CSD, 56 had positive results of CSD skin tests . ELISA antibody levels to A felis did not differ between patients and control subjects, but immunoglobulin M (IgM) and IgG ELISA antibodies to B henselae and B quintana were significantly higher in patients than in control subjects . IFA responses to B henselae and B quintana were also significantly higher in patients than in control subjects . CONCLUSION . Patients with CSD had significant serologic responses to B henselae and B quintana but not to A felis, suggesting that the causative agent of CSD is antigenically related to the Bartonella genus and not to Afipia . The Bartonella IgM ELISA and IFA assay were both sensitive and specific and may be used to establish the diagnosis of CSD.

Carbohydr Res, 1995 Nov 30, 278(1), 143 - 53
Structural studies of the extracellular polysaccharide from Butyrivibrio fibrisolvens strain 49; Ferreira F et al.; The structure of Butyrivibrio fibrisolvens strain 49 capsular polysaccharide has been investigated mainly by sugar and methylation analysis, partial chemical degradations, NMR spectroscopy, and mass spectrometry . The results suggest that the polysaccharide is composed of pentasaccharide repeating units having the following structure . {formula: see text} The polysaccharide contains O-acetyl groups, one of which is substituted to O-3 of the 4-substituted alpha-D-Galp residue, while others occur in non-stoichiometric amounts at other locations.

Biochem Pharmacol, 1995 Nov 27, 50(11), 1753 - 9
Auranofin inhibits the induction of interleukin 1 beta and tumor necrosis factor alpha mRNA in macrophages; Bondeson J et al.; Gold compounds are widely used in the treatment of rheumatoid arthritis, but their mechanisms of action remain unclear . We demonstrate here that auranofin (AF) (0.1-3 microM), but neither the hydrophilic gold compounds aurothiomalate (ATM) and aurothioglucose nor methotrexate or D-penicillamine, inhibits the induction of interleukin 1 beta and tumor necrosis factor (TNF) alpha mRNA and protein by either zymosan, lipopolysaccharide (LPS), or various bacteria in mouse macrophages . The auranofin-mediated inhibition of the induction of TNF-alpha mRNA was stronger than that of interleukin (IL) 1 beta mRNA . AF, but not the other drugs, also inhibited zymosan-induced mobilization of arachidonate . The fact that AF inhibited the induction of mRNA for both these proinflammatory cytokines, irrespective of which stimulus was used, may indicate that it affects some common signal transduction step vital to their induction.

Ann N Y Acad Sci, 1995 Nov 27, 772, 212 - 26
A genetic approach to idiotypic vaccination for B cell lymphoma; Stevenson FK et al.; Idiotypic immunoglobulin expressed by a B cell tumor presents a clear tumor antigen which could be attacked by vaccination of the host . Vaccination with idiotypic protein has been shown to induce protective immunity against lymphoma, but application to patients is limited by the requirement of "personal" vaccines for each patient . A genetic approach enables V-region sequences encoding idiotypic antigen to be rescued from tumor biopsies, and to be assembled as scFv fragments . These can be expressed in bacteria to produce recombinant protein, or used directly as naked DNA vaccines . Intramuscular injection of idiotypic DNA from a mouse B cell lymphoma induces low levels of syngeneic anti-idiotypic antibody in serum . Response can be stimulated by co-injection of DNA plasmids encoding either IL-2 or GM-CSF, and T cells which proliferate in response to idiotypic IgM are generated . However, protection against tumor appears to be blocked by continuing secretion of idiotypic antigen from the persisting vaccine vector, which forms immune complexes with serum antibody . Methods for regulating the level of scFv to engage the immune system, but not to block the effector arm are being investigated . Similar control will be applicable to the cytokine vectors, which can deliver encoded cytokines designed to activate immune pathways for tumor destruction . Experience gained in lymphoma may be extended to other tumors with defined tumor antigens.

J Chromatogr A, 1995 Nov 24, 717(1-2), 71 - 4
Differences between natural and recombinant interleukin-2 revealed by gel electrophoresis and capillary electrophoresis; Knuver-Hopf J et al.; High-performance capillary electrophoresis (HPCE) is shown to be useful for analysis of interleukin-2 (IL-2) in its native state under non-reducing conditions . The results obtained were compared with those from analysis of IL-2 by protein blotting after sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) under denaturing and reducing conditions . In addition, resolution of the different glycosylated and non-glycosylated natural IL-2 species was achieved by HPCE . The HPCE electropherogram of native IL-2 could easily generate quantitative amounts of the different naturally occurring IL-2 species . For HPCE of IL-2 run times of less than 10 min are sufficient, and only extremely small amounts of IL-2 are needed . In this report, human IL-2 expressed in bacteria has been analysed by HPCE and the existence of two recombinant IL-2 forms was demonstrated.

Biochem Biophys Res Commun, 1995 Nov 22, 216(3), 785 - 92
Fibronectin binding domain of P . gingivalis fimbriae; Sojar HT et al.; P . gingivalis fimbriae play an important role in attachment of bacteria to various salivary components as well as to host cells and matrix proteins including fibronectin . In the present study, we investigated the binding domain of P . gingivalis fimbriae to fibronectin using synthetic peptides . A series of 20 mer fimbrillin peptides were used . Binding of fibronectin to purified fimbriae and synthetic peptides was assayed using polyclonal fibronectin antibodies as well as iodinated fibronectin . Purified fimbriae and peptide 126-146 (RMAFTEIKVQMSAAYDNIYTF) showed high levels of binding to fibronectin, while peptide 318-337(HLNVQCTVAEWVLVGQNATW) showed low but statistically significant binding . Our results suggest V-Q-X-X-X-A or V-X-X-X A common domain/domains present in both peptides might be involved in protein-protein interaction between P . gingivalis fimbriae and fibronectin.

Gene, 1995 Nov 20, 165(2), 243 - 8
A multifunctional Urechis caupo protein, PAPS synthetase, has both ATP sulfurylase and APS kinase activities; Rosenthal E et al.; The synthesis of 3'-phosphoadenosine-5'-phosphosulfate (PAPS) from inorganic sulfate and ATP requires two enzymes, ATP sulfurylase (SUL) and adenosine-5'-phosphosulfate kinase (KIN) . In bacteria, fungi, yeast and plants, the two enzymes are present on separate polypeptide chains . We have identified the first animal gene coding for these enzymes . In the marine worm, Urechis caupo (Uc), both SUL and KIN are present on a single polypeptide chain . This protein, which we call PAPS synthetase (PAPSS), is able to complement yeast mutants lacking either enzyme . The Uc PAPSS mRNA is present in oocytes, but is not translated until after fertilization . At least three adult tissues, gut, ceolomocytes and body wall, also contain the mRNA, but at lower concentrations than are found in embryos . Partial sequences of a similar gene from Caenorhabditis elegans (Ce) were detected in a search of the GenBank expressed sequence tag database . Comparison of these Uc and Ce PAPSS sequences with the sequences of cloned genes from non-animal organisms strongly suggests that the animal genes evolved through the fusion of the SUL- and KIN-encoding genes from lower organisms.

Gene, 1995 Nov 20, 165(2), 239 - 42
A cDNA encoding ribosomal protein L3 from the parasitic nematode Toxocara canis; Moore J et al.; A cDNA encoding the ribosomal (r) protein L3 of the parasitic nematode Toxocara canis was isolated from a library constructed from mRNA of the infective larval stage . The encoded protein has a high degree of similarity to r-protein L3 from other organisms, including mammals, yeast, plants and bacteria . The mRNA encoding r-protein L3 is derived from a single-copy gene, and experimental evidence would suggest that it contains the pan-nematode splice leader sequence at its 5' end and that the gene is interrupted by at least three introns.

FEBS Lett, 1995 Nov 20, 375(3), 280 - 2
Enzymatic and immunological activity of 4000 years aged bone alkaline phosphatase; Weser U et al.; Structurally intact and functionally active human bone alkaline phosphatase was isolated from clavicle fragments of IDU, an Egyptian mummy of the Old Kingdom (2150 +/- 50 BC) . Both anion exchange and affinity chromatographies were employed to optimise the preparation of the ancient enzyme resulting in a specific activity of 180 +/- 30 mU/mg . The intactness of the bone enzyme fractions of the wheat-germ lectin affinity chromatography was successfully demonstrated in an ELISA using the monoclonal antibody BAP A . Fortunately, the mummified bone was not contaminated by fungi or bacteria.

Biochemistry, 1995 Nov 14, 34(45), 14722 - 32
Fourier transforms infrared difference spectroscopy of secondary quinone acceptor photoreduction in proton transfer mutants of Rhodobacter sphaeroides; Nabedryk E et al.; In order to investigate the changes of protonation or environment of carboxylic residues occurring upon photoreduction of the secondary quinone acceptor (QB) in the reaction center (RC) of the photosynthetic bacteria Rhodobacter sphaeroides 2.4.1., we have performed light-induced Fourier transform infrared (FTIR) spectroscopy on RCs from wild-type (Wt) and several site-directed mutants . The FTIR QB-/QB spectra have been obtained at pH 7 upon single-saturating flash excitation for native RCs and RC mutants containing either a single-site mutation, with Gln at L212 (EQ L212), Asn at L213 (DN L213), or Asn at L210 (DN L210), or a double-site mutation with both Gln at L212 and Asn at L213 (EQ L212 + DN L213) . The assignment of an IR band to the protonation/deprotonation of a particular carboxylic side chain was analyzed by combining the effects of site-directed mutagenesis and 1H/2H isotope exchange . A positive band at 1728 cm-1 in the QB-/QB spectra was observed in Wt, DN L213, and DN L210 and was absent in the mutants EQ L212 and EQ L212 + DN L213 . The intensity of the 1728 cm-1 band was significantly reduced in 2H2O, and a new feature appears at 1717 +/- 1 cm-1 . Furthermore, the amplitude of the 1728 cm-1 band was similar in native and DN L210 RCs but was increased in DN L213 . This band is attributed to partial proton uptake by Glu L212 estimated to be 0.3-0.4 H+/QB- in native and DN L210 RCs and O.5-0.6 H+/QB- in DN L213 RCs . In contrast, the FTIR QB-/QB spectra show no evidence for change of protonation or environment of Asp L213 upon QB- formation . The increased protonation of Glu L212 in DN L213 RCs is explained by a decreased Glu L212 pKa value due to the loss of a negatively charged Asp L213 . Part of a small differential signal at 1732 (+)/1740 (-) cm-1 that is affected by 1H/2H exchange is tentatively assigned to an environmental shift of the protonated Asp L210 . A negative signal at 1685 cm-1 is propose to arise from the absorption change of the amide I carbonyl mode of Glu L212.(ABSTRACT TRUNCATED AT 400 WORDS)

Biochemistry, 1995 Nov 14, 34(45), 14675 - 86
Influence of charge and polarity on the redox potentials of high-potential iron-sulfur proteins: evidence for the existence of two groups; Heering HA et al.; We have investigated the HiPIPs from Ectothiorhodospira vacuolata (iso-1 and iso-2), Chromatium vinosum, Rhodocyclus gelatinosus, Rhodocyclus tenuis (strain 2761), Rhodopila globiformis, and Rhodospirillum salinarum (iso-2) by direct electrochemistry . Using a glassy carbon electrode with a negatively charged surface, direct, unpromoted electrochemistry is possible with the positively charged HiPIPs . With the negatively charged HiPIPs, the positively charged and flexible bridging promoter poly(L-lysine) is required . The stability of the response can be improved by morpholin, aspartate, tryptophan, or 4,4'-dipyridyl . These "stabilizers" prevent the blocking of the electrode by denatured protein . The redox potential of 500 mV found for R . salinarum iso-2 is the highest HiPIP potential reported . The presence of histidines in the sequence does not per se predict a pH-dependent redox potential . Only C . vinosum and R . gelatinosus HiPIPs show a weak but significant pH dependence with a difference of 35 mV between the low- and the high-pH form and maximum slopes of -20 mV/unit . The dependence of the midpoint potential on temperature and on ionic strength varies over the different HiPIPs . The dependence of the potentials on square root of I cannot be fully explained by the Debye-Huckel theory because the linearity exceeds the limiting concentration and only small negative slopes are observed (o to -28 mV/square root of M) Combination of the sequences, the optical spectra, the overall charges, and the redox thermodynamics suggests that existence of two groups of HiPIPs . One group consists of Chromatium-like HiPIPs with redox potentials between 300 and 350 mV, modulated only by the solvation of the cluster . The second group is formed by Ectothiorhodospira-like HiPIPS with potentials between 50 and 500 mV, modulated by the overall charge of the peptide (25 mV/unit) and by the solvation of the cluster.

Virology, 1995 Nov 10, 213(2), 676 - 9
Inhibition of viral aphid transmission by the N-terminus of the maize dwarf mosaic virus coat protein; Salomon R et al.; Since removal of the exposed N-terminus of the coat protein of some potyviruses abolishes aphid transmission, the role of this coat protein region of maize dwarf mosaic potyvirus (MDMV) in aphid transmission was investigated . The viral cDNA encoding this region was cloned and expressed as a fusion protein in bacteria . The resulting purified N-terminus of the coat protein was used in controlled aphid transmission experiments in competition with MDMV . The results show that this region inhibits aphid transmission of MDMV, indicating a direct involvement of the N-terminal region of the coat protein in aphid transmission.

Gene, 1995 Nov 7, 165(1), 87 - 91
Conservation and variability in Archaea: protein antigens with tandem repeats encoded by a cluster of genes with common motifs in Methanosarcina mazei S-6; Mayerhofer LE et al.; Three open reading frames, orf492, orf375 and orf783, were identified in a 5.9-kb DNA fragment from the genome of Methanosarcina mazei S-6 that code for proteins recognized by antibodies against cell-surface antigens . The deduced amino-acid (aa) sequences of orfs492 and 375, i.e., ORF492 and ORF375, contain seven and four copies of an approx . 42-aa repeat, respectively . The aa sequence of ORF783 contains nine copies of an approx . 85-aa repeat, one of which is also present once in each of the first two ORFs . The organization of the repeats is similar to that of some Gram+ cell-wall-associated proteins . Comparative analyses of aa sequences, compositions and hydropathy profiles of the archaeal ORFs showed similarity with surface (S-) layer and outer-membrane proteins of Bacteria and Archaea.

Gene, 1995 Nov 7, 165(1), 143 - 4
An IS903-based vector for transposon mutagenesis and the isolation of gene fusions; Derbyshire KM; A derivative of the IS903 transposon (Tn) is described that is capable of creating lacZ gene fusions upon transposition . It should find wide use as a tool for Tn mutagenesis in bacteria since it can be used both to generate mutants and to examine gene expression . The transposase-encoding gene (tnp) is located outside the Tn in the vector, thus Tn insertions into a genome are stably maintained in the absence of its cis-acting transposase (Tnp) . The element carries a KmR gene allowing for the direct selection of transposition events in hosts that cannot support pBR322 plasmid replication and facilitating the subcloning of genes into which the Tn has inserted.

Endoscopy, 1995 Nov, 27(9), 671 - 5
Endotoxemia and mediator release during colonoscopy; Berger D et al.; BACKGROUND AND STUDY AIMS: Previous clinical and experimental studies have shown evidence of a leakage of whole bacteria and bacterial products after major trauma through the gut barrier . By determining plasma endotoxin levels, products of the arachidonic pathway, interleukin-6, and the endotoxin-neutralizing capacity (ENC) of plasma during colonoscopy, we studied the gut barrier function and the pathogenetic sequelae of mediator release during a minimally invasive procedure . PATIENTS AND METHODS: Thirty-two patients were enrolled in a controlled prospective study . Endotoxin and ENC were determined by a chromogenic modification of the limulus amebocyte lysate test . Prostanoids and interleukin-6 were measured using commercially available ELISA tests . C-reactive protein levels were checked by nephelometry . RESULTS: Twenty-one of the 32 patients had elevated endotoxin plasma levels during colonoscopy . In one patient, gut-derived bacteria were detected in plasma . ENC decreased after 5 min, and thromboxane B2 levels also started to increase at that time . No acute-phase response took place after 24 h . CONCLUSION: During colonoscopy, endotoxin can be detected in blood . ENC measurement was shown to be even more sensitive . The pathogenetic sequelae leading to gut barrier failure remain unclear, because mediator release and endotoxemia, as checked by ENC, took place simultaneously.

Pathol Res Pract, 1995 Nov, 191(11), 1072 - 77
Suppurative lesions without prominent epithelioid cell response in abscess-forming granulomatous lymphadenitis; Kojima M et al.; To clarify the clinicopathological significance of the suppurative lesions without an epithelioid granulomatous response (SLs without Ep) in lymph nodes and their relationship to abscess-forming granulomatous lymphadenitis (AGL) and cat scratch disease (CSD), 10 cases were assessed clinicopathologically and immunohistologically . SLs without Ep were located in the subcapsular sinus, paracortical area and medullary cords, but not in the germinal centers . The microabscesses were surrounded by collections of monocytoid B-lymphocytes (MBLs), histiocytes without epithelioid features, neutrophils, small lymphocytes and small numbers of plasma cells . The majority of the MBLs seen in the SLs without Ep were of the large cell type . The histological triad of toxoplasmic lymphadenitis, i.e., reactive follicular hyperplasia, small clusters of epithelioid cells and aggregates of MBLs, were also seen in all cases . Some of the clinical and pathological findings in our 10 cases were characteristic of CSD, i.e., (1) cat exposure before the lymphadenopathy was in four of the 10 cases, (2) occurrence in autumn and winter months in all cases, (3) typical suppurative granulomas surrounded by palisaded epithelioid cells were in four of the 10 cases, and (4) Warthin-Starry silver stain-positive bacteria were detected in seven of the 10 cases . The results of our study suggest that SLs without Ep are an early stage of CSD.

Mol Microbiol, 1995 Nov, 18(4), 703 - 14
Mechanism of antigenic variation in Mycoplasma pulmonis: interwoven, site-specific DNA inversions; Bhugra B et al.; The chromosome of the murine pathogen Mycoplasma pulmonis undergoes rearrangements at a high frequency . We show that some of these rearrangements regulate the phase-variable expression of a cluster of genes (the vsa locus) that encode the variable V-1 surface antigens . Only one vsa gene is associated with an expression site; the other vsa genes are transcriptionally silent . The silent genes lack the 5' end region (promoter and ribosome-binding site) that is present in the expressed gene, and DNA rearrangements regulate gene expression by reassorting the 5' end region from an expressed gene with the 3' end region from a previously silent gene . All vsa rearrangements identified so far are site-specific DNA inversions that occur between copies of a specific 34 bp sequence that is conserved in each vsa gene . Interestingly, DNA inversions within the vsa locus apparently occur in concert with inversion of the hsd1 element, which regulates restriction and modification activity in M . pulmonis.

J Prosthet Dent, 1995 Nov, 74(5), 531 - 4
Adsorption of salivary proteins onto prosthetic titanium components; Kohavi D et al.; In vivo adsorption of salivary proteins onto prosthetic titanium components was analyzed after exposure of titanium abutments to the oral environment for a period of 2 to 6 weeks . Gel electrophoresis and Western immunoblotting were used to separate and identify the proteins, which were mainly alpha-amylase and serum albumin . Selective adsorption of proteins enables attachment of specific oral bacteria and thus may alter the composition of the dental plaque formed on titanium surfaces.

Intern Med, 1995 Nov, 34(11), 1082 - 5
Anti-Hu antibody in a patient with Lambert-Eaton myasthenic syndrome and early detection of small cell lung cancer; Tomiyasu K et al.; We report a patient with Lambert-Eaton myasthenic syndrome (LEMS) and anti-Hu antibody, which was an important clue in detecting small cell lung cancer (SCLC) at the early stage . This patient had no symptoms of anti-Hu associated paraneoplastic neurological syndrome . In LEMS patients in whom conventional tests fail to detect malignancy, anti-Hu antibody should be evaluated to diagnose SCLC at the early stage.

Acta Otolaryngol, 1995 Nov, 115(6), 796 - 803
Antibodies to pneumolysin and pneumococcal capsular polysaccharides in middle ear fluid of children with acute otitis media; Virolainen A et al.; Antibodies to pneumococcal pneumolysin and capsular polysaccharides were measured by enzyme immunoassay in 169 acute phase middle ear fluid samples of 116 children with acute otitis media . Antibodies to pneumococcal pneumolysin were detected in 84% and to capsular polysaccharides in 50% of the MEF samples . The Ig class detected most often was IgA to both types of pneumococcal antigens, and it was present in MEF even with non-detectable levels of serum IgA of the same specificity . 59% of the MEF samples positive for IgA to pneumolysin were also positive for secretory component of the same specificity, and 53% of IgA to capsular polysaccharide pool (containing serotypes 6B, 14, 19F, and 23F), respectively . This suggests both leakage of specific IgA from serum to the middle ear and local production of it . In contrast, specific IgG was detected in MEF only with concomitant IgG in serum . Antibodies to pneumolysin occurred in no relation to bacterial findings in MEF . On the contrary, IgG class antibodies to capsular polysaccharides, most likely serum-derived, were detected less often in MEF samples positive for pneumococcus than for other bacteria.

Mol Microbiol, 1995 Nov, 18(3), 559 - 68
Uptake of inorganic carbon in the cyanobacterium Synechocystis PCC6803: physiological and genetic evidence for a high-affinity uptake system; Bedu S et al.; Synechocystis PCC6803 displays two inorganic carbon-uptake processes, a low-affinity one (apparent Km: 300-400 microM) functional in cells grown under standard or limiting inorganic carbon concentrations, and one with a higher affinity (60 +/- 12 microM), detected only in cells adapted to limiting inorganic carbon conditions . A mutational and screening procedure allowed the isolation of a mutant deficient in the high-affinity system, but only slightly impaired in its growth capacities . The mutated genomic region revealed two open reading frames (ORFs), possibly belonging to an operonic structure . A clone in which the downstream ORF, hatR (high-affinity transport), had been inactivated showed a phenotype close to that of the original mutant . Inactivation of the other ORF, hatA, yielded a clone unable to grow in limiting inorganic carbon conditions . The deduced HatA protein showed no homology with any registered protein . It possessed three hydrophobic domains, including a putative signal peptide . Several hypotheses are considered as to its role . The deduced HatR protein, which possessed the features characteristic of the response regulators of the two-component regulatory systems ubiquitous in bacteria, might be a regulator controlling the activity of the high-affinity transport process . It would belong to the subclass of these molecules lacking the DNA-binding domain.

J Dairy Sci, 1995 Nov, 78(11), 2352 - 7
Preparation of apolactoferrin with a very low iron saturation; Feng M et al.; Iron(III) removal from lactoferrin by an iron(III)-chelating resin with immobilized 3-hydroxy-2-methyl-4(1H)-pyridinone ligands was studied at physiological pH in the presence of citrate . The resin had a marked effect on the extent of iron removal . By using the iron(III)-chelating resin, removal of iron from lactoferrin was nearly complete in < 24 h . Apolactoferrin with 4% iron saturation could be prepared conveniently from 100% or from 18% iron-saturated lactoferrin under mild conditions without affecting the iron-binding capacity of the protein . The iron saturation of the obtained apolactoferrin was much lower than that of the apolactoferrin prepared by reported methods.

Biochem Cell Biol, 1995 Nov-Dec, 73(11-12), 775 - 87
Genomic evolution drives the evolution of the translation system; Andersson SG et al.; Our thesis is that the characteristics of the translational machinery and its organization are selected in part by evolutionary pressure on genomic traits have nothing to do with translation per se . These genomic traits include size, composition, and architecture . To illustrate this point, we draw parallels between the structure of different genomes that have adapted to intracellular niches independently of each other . Our starting point is the general observation that the evolutionary history of organellar and parasitic bacteria have favored bantam genomes . Furthermore, we suggest that the constraints of the reductive mode of genomic evolution account for the divergence of the genetic code in mitochondria and the genetic organization of the translational system observed in parasitic bacteria . In particular, we associate codon reassignments in animal mitochondria with greatly simplified tRNA populations . Likewise, we relate the organization of translational genes in the obligate intracellular parasite Rickettsia prowazekii to the processes supporting the reductive mode of genomic evolution . Such findings provide strong support for the hypothesis that genomes of organelles and of parasitic bacteria have arisen from the much larger genomes of ancestral bacteria that have been reduced by intrachromosomal recombination and deletion events . A consequence of the reductive mode of genomic evolution is that the resulting translation systems may deviate markedly from conventional systems.

Arch Oral Biol, 1995 Nov, 40(11), 1023 - 8
Immunocytochemical localization of fibronectin and a 165-kDa membrane protein in the odontoblast layer under initial carious lesions in man; Farges JC et al.; The possible role of fibronectin in dental tissue repair was investigated by comparing its distribution and that of the 165-kDa fibronectin-binding membrane protein (165 kDa-FnBP) in odontoblasts underlying carious and sound dentine . By immunoperoxidase and light microscopy, fibronectin was localized in the dentine underlying the carious lesion, mainly on the surface of the tubule walls, whereas it could not be detected in neighbouring sound zones . The antibody to the 165 kDa-FnBP strongly reacted with the membrane of odontoblasts underlying the lesion, although those facing sound dentine did not express this antigen . Ultrastructurally the 165 kDa-FnBP was localized in the cell membrane at the apical portion of odontoblasts, including the process membrane, beneath the initial lesion; fibronectin was detected in the dentinal area close to the process, and also in contact with its external surface . By a high-resolution immunogold procedure, the proteins were colocalized at the external surface of odontoblast processes . These data suggest that fibronectin present in human carious dentine could modulate the behaviour of underlying odontoblasts by means of newly expressed 165 kDa-FnBP.

Mikrobiologiia, 1995 Nov-Dec, 64(6), 792 - 6
{Use of polymerase chain reaction for detecting the RBPC gene in natural samples}; Chernykh NA; A method was developed allowing detection of the ribulose bisphosphate carboxylase (RuBisCo)-encoding gene in natural samples . The method is based on polymerase chain reaction (PCR) in the presence of oligonucleotide primers complementary to the conserved fragments of the rbcL gene from oxy- and anoxygenic phototrophic bacteria and some chemoautotrophic bacteria . Use of this method made it possible to detect the rbcL gene in samples of natural water and sediments from Antarctic lakes of the Bunger Hills oasis and in samples of Antarctic ground . A correlation was revealed between the results obtained by the PCR-based method and the data on the incorporation of 14CO2 via RuBisCo in natural samples.

Biochem Mol Biol Int, 1995 Nov, 37(5), 885 - 93
Intrinsic mutagenicity and electrophilicity of 1-sulfooxy-3-methylcholanthrene: implications for metabolic activation of the carcinogen 3-methylcholanthrene; Jeong HK et al.; Hydroxylation of a meso-anthracenic carbon atom with subsequent formation of a reactive ester bearing a good leaving group (e.g., sulfate) has been proposed as a possible biochemical mechanism responsible for DNA binding, mutagenicity and tumorigenicity of 3-methylcholanthrene, one of the most potent carcinogenic polycyclic aromatic hydrocarbons in experimental animals . In support of this supposition, the chemically synthesized sulfuric acid ester, 1-sulfooxy-3-methylcholanthrene (1-SMC) was directly mutagenic in bacteria and covalently bound to DNA without metabolic activation . The intrinsic mutagenicity of this reactive ester was significantly potentiated by addition of extra acetate or chloride anions to the media . Reduced glutathione and ascorbic acid protected against 1-SMC-induced mutagenesis . These findings suggest 1-SMC as a potential ultimate electrophilic and tumorigenic metabolite of 3-methylcholanthrene.

Vet Microbiol, 1995 Nov, 47(1-2), 79 - 87
Comparison of the resistance of C57BL/6 and C3H/He mice to infection with Mycobacterium paratuberculosis; Veazey RS et al.; Susceptibility of C57BL/6 (Bcgs) and C3H/HeN (Bcgr) mice to an intraperitoneal infection with Mycobacterium paratuberculosis strain 19698 was compared (by histopathology and the number of mycobacteria isolated from the spleen) . Mycobacterial counts from the spleen of Bcgr mice progressively decreased over the course of infection but remained unchanged in Bcgs mice . Granulomatous lesions and acid-fast bacteria were consistently present in the liver and lymph nodes of Bcgs mice, whereas lesions were transient or absent in Bcgr mice . These results indicate that Bcgr mice are inherently resistant to M . paratuberculosis, whereas Bcgs mice are inherently susceptible . These differences may prove useful in elucidating the mechanisms of resistance and susceptibility to paratuberculosis and other mycobacterial infections.

Vet Microbiol, 1995 Nov, 47(1-2), 27 - 41
Aerosol exposure of pigs to viable or inactivated Actinobacillus pleuropneumoniae serotype 9 induces antibodies in bronchoalveolar lining fluids and serum, and protects against homologous challenge; Hensel A et al.; A dose-defined nose-only inhalation system for pigs was used to study the immunogenic and protective potentials of a single aerosol application of viable or killed Actinobacillus pleuropneumoniae serotype 9 . Respiratory volumes were measured for each pig to calculate inhaled individual doses . Eight pigs inhaled 107 CFU A . pleuropneumoniae CVI 13261 reference strain for serotype 9 . Another eight pigs received an identical dose of killed actinobacilli . After three weeks the pigs and nonexposed controls were challenged with 108 CFU of the homologous strain by aerosol . Bronchoalveolar lavage (BALF) in pigs was performed during the experiment to obtain lavage samples for assessment of local antibodies . Isotype-specific antibody responses in serum and BAL fluids were measured by ELISAs based on whole-cell antigens . The protective efficacy of aerosol immunization was evaluated by clinical and post-mortem examinations . The controls developed fever and severe pleuropneumonia, whereas previously exposed pigs had less fever and less extensive gross pulmonary lesions . After the first aerosol exposure pulmonary IgM, and IgG antibodies reactive with A . pleuropneumoniae increased significantly in both aerosol exposed groups . IgA in BALF and serum concentrations of each Ig class were significantly increased in the group exposed to viable bacteria when compared to the non-exposed controls . After aerosol challenge a pronounced increase of systemic and pulmonary IgA, IgM, and IgG antibodies was detected in both exposure groups . Aerosol application of whole-cell A . pleuropneumoniae bacterins induced similar protective effects against aerosol challenge infection as administration of an identical dose of viable bacteria . Inhalation of A . pleuropneumoniae may lead to asymptomatic carriers in some pigs that could spread the disease under field conditions.

Int Endod J, 1995 Nov, 28(6), 273 - 8
Effect of various zinc oxide materials as root-end fillings on healing after replantation; Pitt Ford TR et al.; This study examined the effect of various zinc oxide materials as root-end fillings of teeth in a replantation model . A total of 35 molar teeth were used from 19 monkeys . After extraction, root ends were resected, the canals contaminated with oral bacteria, root-end cavities prepared and fillings placed prior to replantation . After 8 weeks the teeth and surrounding jaw were removed and prepared for histological examination . Twelve roots were filled with IRM plus dentine chips, and six with Cavit; the tissue response around root ends filled with these materials as assessed by inflammation was similar to that previous reported to IRM and Super EBA cement and was characterized by little or no inflammation of limited extent . In contrast, more severe inflammation was observed around root ends filled with plain zinc oxide-eugenol or Kalzinol; however, the reaction was neither as severe nor as extensive as that to amalgam root-end fillings . Giant cells were observed most often on the surface of fillings with Cavit and zinc oxide-eugenol . It is concluded that the tissue response to IRM with or without added dentine, Super EBA and Cavit was similar and mild; it was less severe than that to zinc oxide-eugenol and Kalzinol . All these materials had a much more favourable response than amalgam

Allerg Immunol (Paris), 1995 Nov, 27(9), 316 - 9
{Natural allergens and recombinant allergens}; Deviller P; Since forty years, many allergens from different species responsible for allergies, have been purified and sometimes identified using classical methods of protein chemistry . For the first time in 1988, molecular biology technologies were applied to allergens, namely to a major allergen of the mite, Dermatophagoides pteronyssinus . During the recent years many other allergens have been produced as recombinant proteins expressed in bacteria or yeast leading to the growing family of recombinant allergens . This talk presents a general view on the allergen cloning procedure and gives an account on future applications of recombinant allergens in both fields of fundamental and practical allergy.

Klin Monatsbl Augenheilkd, 1995 Nov, 207(5), 314 - 5
{Retinochoroiditis as a diagnostic indication of acute systemic toxoplasmosis in an immunocompetent patient}; Wenkel H et al.; HISTORY AND GENERAL INVESTIGATIONS: In February 1993 a 53-year-old immunocompetent man presented at our department with blurred vision on the right eye for 6 weeks . Following a journey to Guatemala in November 1992 he had developed undulating fever up to 40 degrees C (later subfebrile temperature) with loss of weight (15 kg), dysesthesia mainly in the feet and general weakness . He was hospitalized at a general hospital and treated with different antibiotics . Various examinations showed normal results, like cranial computer tomography, and serological tests for virus, bacteria or malaria . Only the transaminases and the borrelia serology (IgG: 1:80, IgM:neg.) were slightly elevated, and the abdominal sonography revealed a moderate hepatomegaly . OPHTHALMOLOGICAL FINDINGS: Visual acuity was 1.0 in both eyes . The right eye showed fatty retrocorneal precipitates, cellular infiltration of the anterior chamber and vitreous and a focal retinochoroiditis next to the superior temporal vessels (Fig . 1a), with corresponding defect in visual field and nerve fiber layer (Fig . 1b, c) . Serology established the diagnosis of an acute generalized toxoplasmosis (IgM ISAGA i.S.: 1:1,600; IgM-AK IFT i.S.: 1:128, KBR i.S.: 1:320) . THERAPY AND CLINICAL COURSE: After adequate chemotherapy ocular symptoms and dysesthesia improved rapidly . The temperature stayed low and the liver parameters returned to normal . CONCLUSION: The ophthalmoscopic finding of an acute focal retinochoroiditis played an important role for the diagnosis of an acute generalized toxoplasmosis in a patient with fever of unknown origin . Ocular manifestation is rare in acute generalized toxoplasmosis.

J Hosp Infect, 1995 Nov, 31(3), 205 - 10
The efficacy of filters used in respiratory function apparatus; Leeming JP et al.; The ability of two low resistance barrier filters (Collins DC-1 and Pall Pf 305) to remove bacteria from expired air was assessed . A specially designed coupling device was used to hold each filter or a disposable plain cardboard mouthpiece a fixed distance (4.5 cm) from a blood agar plate . Volunteers performed maximal forced vital capacity manoeuvres through the assembled apparatus and bacteria impinged on to the agar plate were enumerated . Both filters allowed the transmission of approximately one-third of expired colony forming units . The efficacy of these filters for reducing the likelihood of cross-infection during spirometry is not supported by this study.

J Cell Sci, 1995 Nov, 108 ( Pt 11), 3367 - 75
Drosophila PPY, a novel male specific protein serine/threonine phosphatase localised in somatic cells of the testis; Armstrong CG et al.; Drosophila protein phosphatase Y (PPY) displays 64% amino acid identity to protein serine/threonine phosphatase 1 (PP1) and 39% to protein phosphatase 2A (PP2A) . Here we show by expression of cDNA in bacteria, that PPY is a protein serine phosphatase and that its biochemical properties are distinct from PP1 in both substrate specificity and regulation by the thermostable inhibitory proteins inhibitor 1 and inhibitor 2 . We also demonstrate that PPY is a novel testis specific protein phosphatase by analysis of both mRNA and protein distribution . More precise immunolocalisation within the testis, using affinity purified anti-PPY protein and anti-PPY peptide antibodies, shows that PPY is present in somatic cyst cells, which encase the germ cells . The predominant location of PPY is in the nuclei of both head and tail cyst cells throughout the length of the testis except for the apical tip . The distribution of PPY, coupled with its unique biochemical properties, suggests that PPY may be required to prevent cyst cell division, increase transcription for provision of nutrients to the germ cells and/or provide a signal for spermatocyte differentiation.

Nippon Rai Gakkai Zasshi, 1995 Nov, 64(3), 236 - 45
{Intraepidermal mass of M . leprae in a case of seborrheic keratosis due to Hansen's disease (LLs)}; Yajima M et al.; A 67-year-old patient has had exanthema in the lower right limb since 51 years ago (16 years old at onset), which underwent repeated remission and recurrence . At present, he has bilateral symmetrical widespread infiltrating exanthema and asymmetrical marked neuralhypertrophy, and has been diagnosed typical LLs (His father had the same disease) . The exanthema recurred several years ago, and the patient is being treated for Hansen's disease . He had a dark brown flat elevation with a rough surface and the size of a small finger tip in his right abdominal skin for approximately 20 years . A biopsy was performed, and the specimen was fixed in 10% formalin and paraffin sections were prepared for histopathologic examination . A part of the specimen was processed forscanning electron microscopic examination . Seborrheic keratosis was diagnosed by H & E staining . Acid-fast (FITE) staining, immunohistochemical staining (keratin, S-100 protein, anti-PGL antibody and anti-BCG antibody) and scanning electron microscopy revealed the presence of bacteria (M . leprae) in the dermal foam cells, the matrix with a banded structure and the squamous epithelial cells which normally lack phagocytosis function . Compared to the basal cells of normal epidermis, the basal cells located adjacent to the dermis affected with seborrheic keratosis showed increased proliferation and more marked characteristics of a germinative cell . The degree of differentiation of the basal cells appeared regressed, and they probably possessed augmented phagocytic activity . The phagocytosed bacteria were probably carried by the epidermal cell cycle toward the surface layer . However, bacteria could not be found in the stratum corneum, probably due to an association with the lysosome.

Genetics, 1995 Nov, 141(3), 1015 - 23
Variability within the Seychelles cytoplasmic incompatibility system in Drosophila simulans; Mercot H et al.; In Drosophila simulans, we described a cytoplasmic incompatibility (CI) system (Seychelles) restricted to insular populations that harbor the mitochondrial type SiI . Since then, these populations have been shown to be heterogeneous, some being infected by one Wolbachia genetic variant only (wHa), while others are infected simultaneously by wHa and by another variant (wNo) always found in association with wHa . We have experimentally obtained two D . simulans strains only infected by the wNo variant . This variant determines its own cytoplasmic incompatibility type . In particular, the cross between wNo-bearing flies and wHa-bearing ones is bidirectionally incompatible . The Seychelles CI type, stricto sensu, is distinguished by being determined by the simultaneous presence of two Wolbachia variants that we found to be mutually incompatible . In addition, we observed incomplete maternal transmission of the Wolbachia.

Trends Biochem Sci, 1995 Nov, 20(11), 443 - 8
Evolution of energetic metabolism: the respiration-early hypothesis; Castresana J et al.; The main energy-transducing metabolic systems originated and diversified very early in the evolution of life . This makes it difficult to unravel the precise steps in the evolution of the proteins involved in these processes . Recent molecular data suggest that homologous proteins of aerobic respiratory chains can be found in Bacteria and Archaea, which points to a common ancestor that possessed these proteins . Other molecular data predict that this ancestor was unlikely to perform oxygenic photosynthesis . This evidence, that aerobic respiration has a single origin and may have evolved before oxygen was released to the atmosphere by photosynthetic organisms, is contrary to the textbook viewpoint.

Scand J Gastroenterol, 1995 Nov, 30(11), 1058 - 63
A simple, rapid, and highly reliable capsule-based 14C urea breath test for diagnosis of Helicobacter pylori infection; Hamlet AK et al.; BACKGROUND: Since the urea breath test (UBT) indirectly detects gastric Helicobacter pylori infection by measuring urease activity, the possibility of false-positive results due to other urease-producing bacteria cannot be excluded . Previous studies have shown that increased 14CO2 activity in early breath samples could be attributed to urea hydrolysis in the oropharynx . For that reason, reliable assessment of H . pylori status is hampered for at least 20 min after administration of a 14C-urea drink . METHODS: To overcome this problem we have developed a modified breath test in which 111kBq 14C-urea is supplied in a gelatin capsule, which prevents release of 14C before reaching the stomach . Our modified 14C UBT was evaluated in 100 healthy volunteers, and results were compared with those from enzyme-linked immunosorbent assay serology . RESULTS: The study showed a 99% concordance between the two noninvasive tests . When a biometric method for determination of cut-off values between positive and negative UBT results with the smallest possible arbitrariness was used, the calculated statistical probability of a false diagnosis was lowest in the 10-min breath sample (0.20%), and 100% sensitivity and specificity was achieved . Our capsule method was also compared with the urea drink method and was found more reliable because no overlapping in 14CO2 activity occurred between H . pylori-positive and -negative subjects, whereas conventional breath testing showed overlapping during the whole 30-min test period . Our study also showed that a fatty test meal lowers the 14CO2 excretion the first 20 min and may adversely affect the accuracy of a rapid UBT . CONCLUSIONS: Supplying the 14C-urea in a capsule obviates the problem of false-positive results in early breath samples and makes it possible to diagnose H . pylori infection with 99.8% reliability from a single 10-min breath sample, without the use of a test meal of adjustments for assumed individual CO2 production.

Biomaterials, 1995 Nov, 16(17), 1313 - 8
Azo polymeric hydrogels for colon targeted drug delivery; Shantha KL et al.; Azo polymeric hydrogels were developed for colon specific targeting . Methacryloyloxy azobenzene was synthesized and hydrogels were prepared by copolymerizing with hydroxyethyl methacrylate . These hydrogels were characterized by various spectral techniques such as Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy . Equilibrium swelling measurements of the hydrogels were carried out in distilled water and also in simulated gastric and intestinal fluids . The in vitro release studies of the incorporated 5-flurouracil were carried out in simulated gastric and intestinal fluids . The in vitro release profiles of the drug were also obtained in the presence of azoreductase in the culture of intestinal flora . The release was faster and almost followed a zero order pattern . This can be attributed to the cleavage of the azo crosslinks in the hydrogel by the azoreductase and the release of the entrapped drug at the site of targeting i.e., colon.

Microbiol Res, 1995 Nov, 150(4), 379 - 85
Application of the PCR technique to detect Phytophthora infestans in potato tubers and leaves; Niepold F et al.; A characterized repetitive sequence from Phytophthora infestans (P . infestans) was used to perform a PCR with the DNA from the four races 1, 3, 4, and 1-11 . To obtain amplifiable DNA, all extractions had to be purified by DNA adsorbing spin columns . Only two out of four tested primers were well suited and gave an DNA amplificate of the same size for all four races . After optimization the detection limit of the PCR corresponded to 100 ng of freeze-dried mycelia per ml, specificity was established when testing a collection of the most important potato pathogenic fungi and bacteria . Using P . infestans zoospores to infect tuber slices, the detection threshold was determined to be two days post infection when 3 to 6 zoospores were applied . After infiltrating the tenfold concentration into potato leaves a visible PCR signal was obtained one day post infection . Further improvements of the sensitivity threshold in detecting P . infestans for breeding and prognosis purposes are discussed.

J Cataract Refract Surg, 1995 Nov, 21(6), 679 - 84
Intraocular lens removal from eyes with chronic low-grade endophthalmitis; Busin M et al.; Intraocular lenses (IOLs) were removed from 11 eyes with chronic low-grade endophthalmitis after cataract extraction to restore useful vision and prevent recurrence . One anterior chamber lens, one iris-supported lens, and nine posterior chamber lenses were removed . In the eyes with posterior chamber lenses, the posterior capsule was intact; total (n = 7) or partial (n = 2) capsulectomy was performed in these eyes . Aqueous humor specimens obtained at surgery were positive for bacteria in five eyes, but scanning electron microscopy showed bacteria on all removed IOLs and capsular bags . Final best corrected visual acuity was 20/40 or better in seven eyes . Reduced visual acuity, between 20/50 and 20/400 in three eyes and counting fingers in one eye, was related to retinal detachment (n = 2) and age-related macular degeneration (n = 2) . Transient hyphema was seen in one eye . With a mean follow-up of 21 months (range 10 to 31 months), no recurrence of inflammation was observed . The results show that negative cultures do not preclude a bacterial cause for infection and that primary IOL removal with partial or total capsulectomy provides a surgical approach to the treatment of chronic low-grade endophthalmitis not responsive to medical therapy.

J Clin Periodontol, 1995 Nov, 22(11), 868 - 76
Removal of hard tooth structure by ROOTSHAPE root planing files used with a modified EVA contra-angle; Hugo B et al.; The results of numerous recent investigations indicate that root contamination with bacteria and endotoxins is limited to the root surface only . Therefore, methods on root surfaces instrumentation that preserve root substance should be focused on . Newly available instruments or treatment systems should be evaluated for their root substance-removing potential . The devices for root planing presented here comprised specific files (Rootshape) (with diamond-coating on their convex working surfaces used in conjunction with a water-spray-cooled contra-angle head transforming rotational movements into translatory oscillations . The substance-removal potential of rigid and flexible files with diamond coatings of 2-4, 15, 25 and 40 microns compared with that of regular hand curettes, was evaluated under various working forces . The results demonstrated, that depending on the grit size of the diamond coating, the Rootshape files removed less and in no instance greater amounts of root surface substance than did hand instruments.

APMIS, 1995 Nov, 103(11), 813 - 7
Nitric oxide regulates the chemiluminescence from stimulated human neutrophils; Forslund T et al.; Nitric oxide produced from L-arginine by a variety of cells, is a biologically active compound that can react with iron and thiols . The objective of this study was to investigate the effects of nitric oxide on the respiratory burst from human neutrophils . Treatment with nitroprusside increased the chemiluminescence from neutrophils stimulated with PMA or collagen, but not from cells stimulated with FMLP . Addition of L-arginine increased the chemiluminescence after stimulation with any of the three stimuli, while N omega-nitro-L-arginine methyl ester decreased it . Low doses of nitric oxide, either endogenously or exogenously produced, probably inhibited catalase or glutathione, leading to an increase in hydrogen peroxide available for chemiluminescence detection . This indicates that nitric oxide may reduce the protection against hydrogen peroxide in tissue and in invading catalase-positive bacteria.

Br J Nutr, 1995 Nov, 74(5), 617 - 34
Simulation of the effects of diet on the contribution of rumen protozoa to degradation of fibre in the rumen; Dijkstra J et al.; A previously described mathematical model, that stimulates the metabolic activities of rumen bacteria and protozoa, was used to examine the contribution of protozoa to neutral-detergent fibre (NDF) degradation in the rumen of cattle . Comparisons between predicted and experimentally observed NDF degradation showed general agreement . Further simulations were performed with diets containing variable proportions of concentrate (between 0 and 1 kg/kg diet DM) and at intake levels ranging between 5.3 and 21.0 kg DM/d . The simulated protozoal contribution to NDF degradation was 17-21% at the lowest intake level . Except for the all-concentrate diets, raising the feed intake level reduced this contribution to 5-13% at the highest intake level . The changes in contribution of protozoa to NDF degradation were related to variations in the fibrolytic bacteria: protozoa value and the NDF-degrading activities of protozoa predicted by the model . In simulations where dietary NDF levels were reduced and starch and sugar levels were increased independently, protozoal contribution to NDF degradation generally increased . These differences were reflected also in the generally increased protozoal contribution to NDF degradation predicted in response to a decreased roughage:concentrate value . The contribution of protozoa also generally declined in response to added N . These changes in predicted protozoal contribution to NDF degradation resulting from dietary variations provided possible explanations for the differences in rumen NDF degradation observed when animals are defaunated.

Mil Med, 1995 Nov, 160(11), 547 - 53
Biological warfare in the twentieth century: lessons from the past, challenges for the future; Mobley JA; Biological warfare and fear of biological warfare have affected our wars, our peace, and our research throughout this century . During World War I, animals were deliberately infected with glanders . During World War II, biowarfare research was carried out by Japan, Germany, England, and the United States . Japan carried out biological warfare attacks in China . England used biological warfare for the assassination of Reinhard Heydrich . In the 1950s and 1960s, Army researchers released bacteria over U.S . cities in biological warfare tests . The most frequent biological warfare terrorist episodes have been contamination of food and water . Although biological warfare can be very low tech, genetic engineering is capable of making biowarfare agents available in vast quantities . Biowarfare research should continue, but the National Institutes of Health should oversee human biological warfare research.

Br J Rheumatol, 1995 Nov, 34 Suppl 2, 16 - 9
Sulphasalazine, sulphapyridine or 5-aminosalicylic acid--which is the active moiety in rheumatoid arthritis?
Bird HA.
Sulphasalazine is cleaved into 5-aminosalicylic acid and sulphapyridine by colonic bacteria . The bulk of evidence favours sulphapyridine rather than 5-aminosalicylic acid as the active moiety (as well as the main producer of side-effects) though a therapeutic action from the 30% of sulphasalazine that is absorbed unaltered also cannot be excluded.

Microbiology, 1995 Nov, 141 ( Pt 11), 2985 - 93
Methanol oxidation mutants in Methylobacterium extorquens AM1: identification of new genetic complementation groups; Springer AL et al.; Two-hundred-and-eight new Methylobacterium extorquens AM1 methanol oxidation (Mox) mutants were isolated and placed into complementation groups . Complementation analyses identified new Mox groups in the Mxb and Mxc loci and at a new locus, Mxd . Thirty-seven mutants at the Mxb locus were divided into MxbM and MxbD complementation groups on the basis of their complementation pattern . Twenty-nine mutants at the Mxc locus fell into three complementation groups, MxcB, MxcQ and MxcE . The direction of transcription for genes at this locus could be inferred from the subclones . Eighteen of the new mutants were not complemented by previously isolated M . extorquens AM1 clones but were complemented by two new overlapping clones . This locus was called Mxd and the mutants fell into two complementation groups, MxdR and MxdS . Immunoblots from all these mutant classes showed that all of the Mxb and Mxc strains had substantially reduced levels of MxaF (large subunit of methanol dehydrogenase) and cytochrome cL, compared to the wild-type . These mutants, particularly the Mxb mutants, also had elevated levels of cytochrome c-553 . These results are consistent with a role for the MxbMD and MxcBQE complementation groups in the regulation of expression of mxaF . The MxdR and MxdS mutants had normal levels of MxaF and both c-type cytochromes.

J Dent Res, 1995 Nov, 74(11), 1796 - 801
Simultaneous detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by a rapid PCR method; Wahlfors J et al.; The identification of periodontal pathogens by conventional methods is time-consuming and difficult . Therefore, a multiplex PCR method for simultaneous detection of Actinobacillus actinomycetemcomitans (A.a.) and Porphyromonas gingivalis (P.g.) was developed for rapid and easy determination of these risk-indicator bacteria in human periodontal disease . The PCR primers were designed to hybridize to various regions of 16S rRNA genes, and a hot-start technique was used to obtain maximum sensitivity and specificity . This method can detect both of these bacteria in subgingival plaque samples at concentrations as low as 5 to 50 cells per sample . The sensitivity, however, was even 10 times better when the bacteria were analyzed in a water suspension . Since the only step between sample collection and the actual analysis is a brief centrifugation of the patient sample, the detection can be readily carried out in four hours . The performance of the method was studied with 36 patient samples . The results showed that the PCR method detected A.a . (44% vs . 25%, respectively) and P.g . (56% vs . 42%, respectively) more often than the conventional culture in plaque samples . Thus, our multiplex PCR method is rapid and more effective than conventional protocols in detecting these periodontal pathogens.

Appl Environ Microbiol, 1995 Nov, 61(11), 4110 - 3
Sequence and expression of a xylanase gene from the hyperthermophile Thermotoga sp . strain FjSS3-B.1 and characterization of the recombinant enzyme and its activity on kraft pulp; Saul DJ et al.; A gene expressing xylanase activity was isolated from a genomic library of Thermotoga sp . strain FjSS3-B.1 . The sequence of the gene shows that it encodes a single domain, family 10 xylanase . The recombinant enzyme has extremely high thermal stability, activity over a relatively broad pH range, and activity on Pinus radiata kraft pulp.

Eur J Biochem, 1995 Nov 1, 233(3), 727 - 35
Biochemical characterization of the 8-hydroxy-5-deazaflavin-reactive hydrogenase from Methanosarcina barkeri Fusaro; Michel R et al.; The membrane-associated coenzyme F420-reactive hydrogenase of the anaerobic methanogenic archaeon Methanosarcina barkeri Fusaro has been purified 95-fold to apparent homogeneity . A new purification procedure and altered storage conditions gave substantially higher yield (13.4% versus 4.3%) and specific coenzyme F420-reducing activity (82.8 mumol.min-1.mg protein-1 versus 11.5 mumol.min-1.mg protein-1) than reported previously {Fiebig, K . & Friedrich, B . (1989) Eur . J . Biochem . 184, 79-88} . The predominant coenzyme F420-reactive form of the hydrogenase has an apparent molecular mass of 198 kDa and is composed of three non-identical subunits with apparent molecular masses of 48 (alpha), 33 (beta), and 30 kDa (gamma), apparently in a stoichiometry of alpha 2 beta 2 gamma 1 . This minimal coenzyme F420-reducing hydrogenase formed aggregates with apparent molecular masses of approximately 845 kDa . 1 mol of the 198-kDa form of hydrogenase contained 2 mol FAD, 2 mol nickel, 28-32 mol non-heme iron, and 34 mol acid-labile sulfur; in addition, 0.2 mol selenium was detected . The isoelectric point was 5.30 . The amino acid sequence PXXRXEGH, where X is any amino acid, was found to be conserved in the N-termini of the putative nickel-binding subunits of most {NiFe}- and {NiFeSe}hydrogenases of methanogenic Archaea and Bacteria . However, this motif was not detected in the protein sequences of {Fe}hydrogenases . Maximal coenzyme F420-reducing activity was obtained with reductively reactivated enzyme at 55 degrees C in the pH range 6.5-7.25 . The Km values of the purified enzyme for H2 with coenzyme F420 or methylviologen as electron acceptor were extremely low, namely 3 microM and 4 microM . The catalytic efficiency coefficients (kcat/Km) for H2 with both reducible cosubstrates were high: 2.5 x 10(7) M-1.s-1 with coenzyme F420 and 6.9 x 10(7) M-1.s-1 with methylviologen.

J Eukaryot Microbiol, 1995 Nov-Dec, 42(6), 679 - 84
Phylogeny of the large extrachromosomal DNA of organisms in the phylum Apicomplexa; Egea N et al.; Organisms in the phylum Apicomplexa appear to have a large extrachromosomal DNA which is unrelated to the mitochondrial DNA . Based on the apparent gene content of the large (35 kb) extrachromosomal DNA of Plasmodium falciparum, it has been suggested that it is a plastid-like DNA, which may be related to the plastid DNA of rhodophytes . However, phylogenetic analyses have been inconclusive . It has been suggested that this is due to the unusually high A+T content of the Plasmodium falciparum large extrachromosomal DNA . To further investigate the evolution of the apicomplexan large extrachromosomal DNA, the DNA sequence of the organellar ribosomal RNA gene from Toxoplasma gondii, was determined . The Toxoplasma gondii rDNA sequence was most similar to the large extrachromosomal rDNA of Plasmodium falciparum, but was much less A+T rich . Phylogenetic analyses were carried out using the LogDet transformation to minimize the impact of nucleotide bias . These studies support the evolutionary relatedness of the Toxoplasma gondii rDNA with the large extrachromosomal rDNA of Plasmodium falciparum and with the organellar rDNA of another parasite in the phylum Apicomplexa, Babesia bovis . These analyses also suggest that the apicomplexan large extrachromosomal DNA may be more closely related to the plastid DNA of euglenoids than those of rhodophytes.

J Bacteriol, 1995 Nov, 177(22), 6552 - 9
Generation mechanism and purification of an inactive form convertible in vivo to the active form of quinoprotein alcohol dehydrogenase in Gluconobacter suboxydans; Matsushita K et al.; Alcohol dehydrogenase (ADH) of acetic acid bacteria is a membrane-bound quinohemoprotein-cytochrome c complex involved in vinegar production . In Gluconobacter suboxydans grown under acidic growth conditions, it was found that ADH content in the membranes was largely increased but the activity was not much changed, suggesting that such a condition produces an inactive form of ADH (inactive ADH) . A similar phenomenon could be also observed in Acetobacter aceti, another genus of acetic acid bacteria . Furthermore, aeration conditions were also shown to affect ADH production; the ADH level was increased and was present as an active form under low-aeration conditions, while the ADH level was decreased and was present mainly as an inactive form under high-aeration conditions . Inactive ADH was solubilized from the membranes of G . suboxydans grown in acidic and high-aeration conditions and was purified separately from the normal, active form of ADH (active ADH) . In spite of having 10 times less enzyme activity than active ADH, inactive ADH could not be distinguished from active ADH with respect to their subunit compositions, molecular sizes, and prosthetic groups . Inactive ADH, however, had a relatively loose conformation with a partially oxidized state, while active ADH had a tight conformation with a completely reduced state, suggesting that inactive ADH may lack a right subunit's interaction and that one of the heme c components may be inactivated . Reactivation from such an inactive ADH occurred either by shifting of the pH of the culture medium up during the cultivation or by incubation of the resting cells at the neutral pH region in the presence of an energy source such as D-sorbitol . Such an activation of ADH was repressed by the addition of a proton uncoupler and could not occur in the spheroplasts . Thus, the results suggest that inactive ADH could be generated abundantly under acidic growth conditions and converted to the active form at a neutral culture pH . The data also suggest that some periplasmic component may be involved in the conversion of inactive ADH into the active form by consuming some forms of energy.

J Bacteriol, 1995 Nov, 177(22), 6499 - 505
Identification and functional analysis of the transfer region of plasmid pMEA300 of the methylotrophic actinomycete Amycolatopsis methanolica; Vrijbloed JW et al.; Amycolatopsis methanolica contains a 13.3-kb plasmid (pMEA300) that is present either as an integrated element or as an autonomously replicating plasmid . Conjugational transfer of pMEA300 results in pock formation, zones of growth inhibition that become apparent when plasmid-carrying donor cells develop in a confluent lawn of plasmid-lacking recipient cells . A 6.2-kb pMEA300 DNA region specifying the functions of conjugation and pock formation was sequenced, revealing 10 open reading frames . This is the first sequence of the transfer region of a plasmid from a nonstreptomycete actinomycete . No clear similarities were found between the deduced sequences of the 10 putative Tra proteins of pMEA300 and those of Streptomyces plasmids . All Tra proteins of pMEA300 thus may represent unfamiliar types . A detailed mutational analysis showed that at least four individual proteins, TraG (9,488 Da), TraH (12,586 Da), TraI (40,468 Da), and TraJ (81,109 Da), are required for efficient transfer of pMEA300 . Their disruption resulted in a clear reduction in the conjugational transfer frequencies, ranging from (5.2 x 10(1))-fold (TraG) to (2.3 x 10(6))-fold (TraJ), and in reduced pock sizes . At least two putative proteins, TraA (10,698 Da) and TraB (31,442 Da), were shown to be responsible for pock formation specifically . Specific binding of the pMEA300-encoded KorA protein to the traA-korA intragenic region was observed.

Exp Cell Res, 1995 Nov, 221(1), 66 - 72
Delayed translation and posttranslational processing of cyritestin, an integral transmembrane protein of the mouse acrosome; Linder B et al.; This paper presents data on the cellular localization of the testis-expressed mouse Cyrn gene product, cyritestin . This cysteine-rich protein is a member of a family including various rodent and primate proteins and snake venom proteins of the metalloproteinase and disintegrin types . By using antibodies raised against recombinant proteins generated in bacteria and against synthetic peptides we show that (i) Cyrn mRNA is present in germ cells 4 days prior to translation; (ii) cyritestin protein is localized in the acrosomal region of spermatids and spermatozoa; and (iii) cyritestin has an apparent molecular weight of 110,000 Daltons, but is subject to processing during epididymal sperm transport, resulting in a shorter molecule lacking approximately 55 kDa from the N-terminal half . We conclude that cyritestin becomes exposed on the sperm surface after successful acrosome reaction and thus may play a role in sperm function rather than in testicular germ cell maturation.

Carcinogenesis, 1995 Nov, 16(11), 2779 - 84
Mutagenicity of a unique 8-oxoguanine in a human Ha-ras sequence in mammalian cells; Le Page F et al.; The processing of a unique 8-oxoguanine residue in DNA has been studied in mammalian cells using a single-stranded shuttle vector . A fragment of human Ha-ras carrying the lesion on the first (G1) or the second guanine (G2) of codon 12 was inserted in a shuttle plasmid . Extrachromosomal DNA is replicated in animal cells, extracted and used to transform bacteria to be amplified and individualized . DNA sequencing of bacterial clones showed the mutagenic potency of 8-oxoguanine in vivo to be approximately 4% . The presence of the 8-oxoguanine does not greatly affect survival of the progeny . No significant difference was observed between the mutation frequencies induced by 8-oxoguanine located either at the G1 or G2 position . The majority of the mutations, targeted at the lesion level, are G to T transversions . These base substitutions induced respectively glycine to cysteine (G1) or valine (G2) change in the P21ras protein . These mutations may contribute to activation of the protooncogene, leading to spontaneous tumorigenesis.

Nat Struct Biol, 1995 Nov, 2(11), 975 - 82
Pseudospecific docking surfaces on electron transfer proteins as illustrated by pseudoazurin, cytochrome c550 and cytochrome cd1 nitrite reductase; Williams PA et al.; The structure of pseudoazurin from Thiosphaera pantotropha has been determined and compared to structures of both soluble and membrane-bound periplasmic redox proteins . The results show a matching set of unipolar, but promiscuous, docking motifs based on a positive hydrophobic surface patch on the electron shuttle proteins pseudoazurin and cytochrome c550 and a negative hydrophobic patch on the surface of their known redox partners . The observed electrostatic handedness is argued to be associated with the charge-asymmetry of the membrane-bound components of the redox chain due to von Heijne's 'positives-inside' principle . We propose a 'positives-in-between' rule for electron shuttle proteins, and expect a negative hydrophobic patch to be present on both the highest and lowest redox potential species in a series of electron carriers.

Nat Struct Biol, 1995 Nov, 2(11), 946 - 50
High-resolution structural studies of the factor XIIIa crosslinking site and the first type 1 module of fibronectin; Potts JR et al.; The N-terminal domain of fibronectin undergoes factor XIIIa-catalysed crosslinking to fibrin, bacteria and collagen . The reactive glutamine residue is in an extended, random coil 'tail' of about 18 residues that would be accessible for crosslinking.

Mol Cell Biol, 1995 Nov, 15(11), 6222 - 31
Mutational analysis of mRNA capping enzyme identifies amino acids involved in GTP binding, enzyme-guanylate formation, and GMP transfer to RNA; Cong P et al.; Vaccinia virus mRNA capping enzyme is a multifunctional protein with RNA triphosphatase, RNA guanylyltransferase, RNA (guanine-7) methyltransferase, and transcription termination factor activities . The protein is a heterodimer of 95- and 33-kDa subunits encoded by the vaccinia virus D1 and D12 genes, respectively . The capping reaction entails transfer of GMP from GTP to the 5'-diphosphate end of mRNA via a covalent enzyme-(lysyl-GMP) intermediate . The active site is situated at Lys-260 of the D1 subunit within a sequence element, KxDG (motif I), that is conserved in the capping enzymes from yeasts and other DNA viruses and at the active sites of covalent adenylylation of RNA and DNA ligases . Four additional sequence motifs (II to V) are conserved in the same order and with similar spacing among the capping enzymes and several ATP-dependent ligases . The relevance of these common sequence elements to the RNA capping reaction was addressed by mutational analysis of the vaccinia virus D1 protein . Nine alanine substitution mutations were targeted to motifs II to V . Histidine-tagged versions of the mutated D1 polypeptide were coexpressed in bacteria with the D12 subunit, and the His-tagged heterodimers were purified by Ni affinity and phosphocellulose chromatography steps . Whereas each of the mutated enzymes retained triphosphatase, methyltransferase, and termination factor activities, six of nine mutant enzymes were defective in some aspect of transguanylylation . Individual mutations in motifs III, IV, and V had distinctive effects on the affinity of enzyme for GTP, the rate of covalent catalysis (EpG formation), or the transfer of GMP from enzyme to RNA . These results are concordant with mutational studies of yeast RNA capping enzyme and suggest a conserved structural basis for covalent nucleotidyl transfer.

Gastroenterology, 1995 Nov, 109(5), 1685 - 99
DNA mismatch repair and cancer; Chung DC et al.; The genetic basis of cancer involves certain classes of genes, particularly oncogenes, tumor-suppressor genes, and DNA mismatch repair genes . Originally identified in bacteria and yeast, the human homologues of DNA mismatch repair genes have been implicated in the pathogenesis of the hereditary nonpolyposis colorectal cancer syndromes, as well as a variety of different sporadic cancers . An appreciation of their role in cancer is predicated on an understanding of their function in the processes of DNA repair . This article reviews the recent developments and advances in the biology of the human DNA mismatch repair genes and their involvement in the pathogenesis of cancer.

J Mol Evol, 1995 Nov, 41(5), 582 - 6
Sense in antisense?
Forsdyke DR.
A correspondence between open reading frames in sense and antisense strands is expected from the hypothesis that the prototypic triplet code was of general form RNY, where R is a purine base, N is any base, and Y is a pyrimidine . A deficit of stop codons in the antisense strand (and thus long open reading frames) is predicted for organisms with high G + C percentages; however, two bacteria (Azotobacter vinelandii, Rhodobacter capsulatum) have larger average antisense strand open reading frames than predicted from (G + C)% . The similar codon frequencies found in sense and antisense strands can be attributed to the wide distribution of inverted repeats (stem-loop potential) in natural DNA sequences.

Biochem J, 1995 Nov 1, 311 ( Pt 3), 1021 - 3
The Gly-54-->Asp allelic form of human mannose-binding protein (MBP) fails to bind MBP-associated serine protease; Matsushita M et al.; The human mannose-binding protein (MBP) is a pattern recognition molecule that appears to play a role in initial host defence . MBP activates the complement cascade and it may act as an opsonin both in the absence and in the presence of complement . A number of distinct MBP allelic forms exist in different population groups . An allele that occurs in 5-7% of Caucasians was identified by an inability to activate the complement system . A homozygous mutation at base pair 230 of the MBP gene results in a Gly-to-Asp substitution at the fifth collagen repeat . It appears that the resultant protein, MBPD, is able to form high-order multimers that bind bacteria but do not support complement activation . Recently a novel serine protease, the MBP-associated serine protease (MASP), has been described . MBP-MASP complexes circulate in serum and result in the direct activation of a novel complement pathway (lectin pathway) in the absence of the first complement components . In this study we demonstrate that MASP and its proenzyme proMASP are unable to bind to recombinant (r)MBPD . This lack of a MASP-rMBPD association corresponds to a failure of the Gly-54-->Asp form of MBP to activate complement . Our results provide a biochemical basis for the functional deficit in the Gly-54-->Asp allelic form of MBP and suggest that the proMASP/MASP binding site maps to the fifth collagen repeat of MBP.

Am J Med Sci, 1995 Nov, 310(5), 206 - 13
Case report: in situ hybridization for detection of inapparent infection with Chlamydia trachomatis in synovial tissue of a patient with Reiter's syndrome; Beutler AM et al.; The authors have shown that protein antigens, RNA, and DNA from Chlamydia trachomatis are present in synovial tissues of patients with Reiter's syndrome (RS) . However, those studies gave no insight into the host cell type involved or the precise tissue location of the bacteria . To address such issues, the authors developed an in situ hybridization system to detect chlamydia, and they used that system to examine synovial biopsies from a patient with RS and a patient without RS . The in situ system uses a previously described digoxigenin-labeled DNA probe that hybridizes with chlamydial 16S rRNA sequences in paraformaldehyde-fixed samples . Control studies with chlamydia-infected and uninfected HeLa cells confirmed that the in situ system is as sensitive as is direct fluorescence cytology for detection of the organism . Morphology of host and chlamydia cells is preserved after hybridization . Studies using synovial tissue from an osteoarthritis patient produced no in situ hybridization signal, but similar hybridization to tissue from a culture-/direct fluorescence cytology- negative RS patient had a strong intracellular signal for chlamydia within a subsynovial cell layer . These in situ hybridization results confirm the extensive presence of chlamydia in synovia and extend the authors' earlier observation that chlamydia RNA is present in the synovia of patients with RS . The data also confirm their electron microscopy studies, indicating that chlamydia are intracellular in synovial tissue, and they further show that infected host cells are located beneath the synovial lining.

Leukemia, 1995 Nov, 9(11), 1910 - 20
Effects of interleukin 10 on blast cells derived from patients with acute myelogenous leukemia; Bruserud O et al.; The effect of interleukin 10 (IL-10) on proliferation and cytokine secretion by acute myelogenous leukemia (AML) blast cells was investigated in vitro . IL-10 inhibited spontaneous AML blast proliferation for a majority of patients, whereas in the presence of exogenous growth factors (granulocyte-stimulating factor, G-CSF; granulocyte-macrophage colony-stimulating factor, GM-CSF; interleukin 3) the IL-10 effect on blast proliferation showed a wide variation depending on the individual AML patient . IL-10 seemed to cause an irreversible inhibitory effect on AML blasts, as inhibition could also be demonstrated when IL-10 was present only during the initial preincubation of the leukemia cells . IL-10 also inhibited AML blast colony formation . However, independent of the effect on AML blast proliferation, IL-10 decrease cytokine secretion from AML blast cells for all patients, as demonstrated for IL-1 alpha, IL-1 beta, tumor necrosis factor-alpha, GM-CSF and interleukin 6 . IL-10 did not inhibit development of apoptosis in AML blasts cultured in vitro . Expression of complement receptors and capability to adhere and internalize bacteria by AML blasts were not altered by IL-10.

J Virol, 1995 Nov, 69(11), 7187 - 95
Herpes simplex virus trans-regulatory protein ICP27 stabilizes and binds to 3' ends of labile mRNA; Brown CR et al.; Previous work demonstrated that a herpes simplex virus type 1 (HSV-1) immediate-early function up-regulates beta interferon but not chloramphenicol acetyltransferase reporter genes driven by the strong simian virus 40 (SV40) or cytomegalovirus promoter-enhancer regions in both transient assays and stable cell lines . The different 3' mRNA stabilization and RNA-processing signals from these two reporter genes appeared to be primarily responsible for this phenomenon . We now report that the HSV-1 ICP27 itself is sufficient to stimulate both steady-state accumulation and increased half-life of beta interferon reporter gene mRNA . Furthermore, the ability to respond directly to cotransfected ICP27 can be transferred to chloramphenicol acetyltransferase reporter genes by replacement of their SV40-derived splicing and poly(A) signals with the 3' AU-rich and poly(A) RNA-processing signals from the normally highly labile beta interferon and c-myc mRNA species . ICP27 expressed in bacteria bound specifically to in vitro-generated RNA from both the beta interferon and c-myc intronless AU-rich 3' RNA-processing regions, but not to the SV40-derived early-region splice signal and poly(A) sequences . By site-specific mutagenesis, we also show that individual ICP27 C-terminal amino acid residues that are positionally conserved in ICP27 homologs in other herpesviruses (D-357, E-358, H-479, C-400, C-483, and C-488) are critical for trans-regulatory activity . Importantly, several of these positions match mutations that are known to be essential for the role of ICP27 in the early-to-late switch during the virus lytic cycle . Therefore, our findings support the notion that HSV ICP27 modulates gene expression posttranscriptionally in part by targeting RNA.

FEBS Lett, 1995 Oct 30, 374(2), 157 - 60
Reconstitution photoactive yellow protein from apoprotein and p-coumaric acid derivatives; Imamoto Y et al.; We report reconstitution of photoactive yellow protein (PYP) from apoPYP and p-coumaric acid derivatives . The addition of p-coumaric acid to the apoPYP sample did not result in the recovery of PYP . In contrast, yellow products were obtained by the addition of p-coumaryl thiophenyl ester or p-coumaric anhydride to the apoPYP sample, the absorption spectra of which were indistinguishable from the spectrum of intact PYP . Our findings provide strong evidence that PYP has the p-coumaryl chromophore . This reconstitution technique opens the way for further biophysical studies of PYP using artificial chromophore analogs.

Gene, 1995 Oct 27, 164(2), 211 - 8
Purification of a high-mobility-group 1 sea-urchin protein and cloning of cDNAs; Niemeyer CC et al.; The isolation of the sea urchin high-mobility-group 1 (HMG1) protein, the cloning of corresponding cDNA clones and the similarity to the human homologue are described . Sea urchin HMG1 was purified as one of the nuclear embryonic proteins which associate with an upstream regulatory element (E1) of the Strongylocentrotus purpuratus (Sp) CyIIIb actin-encoding gene . Using a synthetic oligodeoxyribonucleotide (oligo) which includes the E1 cis-acting element in a DNA affinity chromatography purification, the most prominent of the binding proteins was isolated and the N terminus sequenced . cDNA clones were isolated by screening an embryonic cDNA library with a synthetic oligo derived from the amino acid (aa) sequence . Comparison of the cDNAs ORF to known proteins revealed a 50% aa identity to the mammalian HMG1 and all the structural characteristics of this group of proteins . The sea urchin protein, SpHMG1, was synthesized in bacteria, as well as translated in vitro . Binding assays carried out with the recombinant SpHMG1 protein did not produce specific in vitro complexes with E1.

J Immunol Methods, 1995 Oct 26, 186(2), 305 - 12
A modified screening method for pcDNA-1 expression libraries which is applicable to both surface and intracellular antigens . Cloning of a colon carcinoma antigen; Grimm T et al.; A modification of the COS cell transient expression system for isolating cDNAs encoding antibody defined molecules was used to clone the carcinoma antigen defined by monoclonal antibody CORC-6 . Bacteria were transformed with cDNA prepared from colon carcinoma cells and immediately divided into aliquots containing approximately 500 independent clones . The aliquots were grown for 8 h before frozen . Screening was performed by isolating plasmid from each aliquot, transfecting COS-7 cells, and staining the fixed cells with monoclonal antibodies . The aliquot giving rise to antigen expressing cells was then subdivided until a single antigen encoding colony was obtained . This approach allows a library to be rescreened and is equally applicable to cytoplasmic and surface localized antigens . Using this approach, the antigen defined by CORC-6 was identified as carcinoembryonic antigen.

Mol Gen Genet, 1995 Oct 25, 248(6), 686 - 94
MMK2, a novel alfalfa MAP kinase, specifically complements the yeast MPK1 function; Jonak C et al.; Mitogen-activated protein (MAP) kinases are serine/threonine protein kinases that are activated in response to a variety of stimuli . Here we report the isolation of an alfalfa cDNA encoding a functional MAP kinase, termed MMK2 . The predicted amino acid sequence of MMK2 shares 65% identity with a previously identified alfalfa MAP kinase, termed MMK1 . Both alfalfa cDNA clones encode functional kinases when expressed in bacteria, undergoing autophosphorylation and activation to phosphorylate myelin basic protein in vitro . However, only MMK2 was able to phosphorylate a 39 kDa protein from the detergent-resistant cytoskeleton of carrot cells . The distinctiveness of MMK2 was further shown by complementation analysis of three different MAP kinase-dependent yeast pathways; this revealed a highly specific replacement of the yeast MPK1(SLT2) kinase by MMK2, which was found to be dependent on activation by the upstream regulators of the pathway . These results establish the existence of MAP kinases with different characteristics in higher plants, suggesting the possibility that they could mediate different cellular responses.

J Biol Chem, 1995 Oct 20, 270(42), 25291 - 300
Definition of a minimal domain of the dioxin receptor that is associated with Hsp90 and maintains wild type ligand binding affinity and specificity; Coumailleau P et al.; The dioxin receptor is a cytoplasmic basic helix-loop-helix/Per-Arnt-Sim homology (bHLH/PAS) protein known to bind planar polycyclic ligands including polycyclic aromatic hydrocarbons, benzoflavones, heterocyclic amines, and halogenated aromatic hydrocarbons, e.g . dioxins . Ligand-induced activation of the dioxin receptor initiates a process whereby the receptor is transformed into a nuclear transcription factor complex with a specific bHLH/PAS partner protein, Arnt . In analogy to the glucocorticoid receptor, the latent dioxin receptor is found associated with the molecular chaperone hsp90 . We have defined and isolated a minimal ligand binding domain of the dioxin receptor from the central PAS region, comprising of amino acids 230 to 421, and found this domain to interact with hsp90 in vitro . Expression of the minimal ligand binding domain in wheat germ lysates or bacteria, systems which harbor hsp90 homologs unable to interact with the glucocorticoid or dioxin receptors, resulted in non-ligand binding forms of this minimal 230 to 421 fragment . Importantly, affinity of the minimal ligand binding domain for dioxin was similar to the affinity inherent in the full-length dioxin receptor, and a profile of ligand structures which specifically bound the minimal ligand binding domain was found to be conserved between this domain and the native receptor . These experiments show that the minimal ligand binding domain maintains the quantitative and qualitative aspects of ligand binding exhibited by the full-length receptor, implying that the central ligand binding pocket may exist to accommodate all classes of specific dioxin receptor ligands, and that this pocket is critically dependent upon hsp90 for its ligand binding conformation.

Blood, 1995 Oct 15, 86(8), 3205 - 10
Primary structure of murine red blood cell-type pyruvate kinase (PK) and molecular characterization of PK deficiency identified in the CBA strain; Kanno H et al.; To clarify the molecular abnormality of pyruvate kinase (PK) deficiency identified in the mutant mice of CBA-Pk-1slc/Pk-1slc, we cloned murine red blood cell-type PK (R-PK) cDNA of those animals . The cDNA sequence spans 1827 bp, including an open reading frame that can encode 574 amino acids . Homology in the coding sequences between murine and human R-PK was 86.1% at nucleotide and 91.5% at amino acid levels . A homozygous missense mutation at nucleotide 1013 GGT-->GAT was identified in the cDNA sequence of the mutant, causing a single amino acid substitution at no . 338Gly-->Asp of the murine R-PK . Six amino acid residues, 335Val-336Ala-337Arg-338Gly-339Asp-340L eu, were encoded in exon 8 of both human and rat L (liver-type)/R-PK genes and were evolutionarily conserved in PK from bacteria through humans . 337Arg was reported to be important for substrate binding, suggesting that the amino acid change would impair substrate affinity of the PK subunit . A homozygous missense mutation at the catalytic domain has been identified in a human PK variant, PK Hong Kong (941ATT-->ACT, 314 Ile-->Thr) . Although both 1013A and 941C gave rise to an amino acid change adjacent to the active site and may interfere with substrate binding to the subunit, the degree of anemia was much more severe in the human case . The erythroid-progenitor cell number increased in the spleen of Pk-1slc/Pk-1slc mice to a level approximately 66 times higher than that in normal CBA mice, suggesting that compensatory extramedullary erythropoiesis in the spleen of the mutant mice, but not in the human variant, might account for the observed difference in the phenotype.

J Immunol, 1995 Oct 15, 155(8), 3972 - 8
Binding of FimD on Bordetella pertussis to very late antigen-5 on monocytes activates complement receptor type 3 via protein tyrosine kinases; Hazenbos WL et al.; Nonopsonized Bordetella pertussis bind to human monocytes by means of the virulence factors filamentous hemagglutinin (FHA), pertactin, and the minor fimbrial subunit FimD . Receptors on monocytes that mediate binding of B . pertussis to these cells include complement receptor type 3 (CR3), which binds to FHA of B . pertussis, and very late antigen-5 (VLA-5), which binds to an, as yet, unknown ligand on these bacteria . In the present study, the possibility that FimD acts as a ligand for VLA-5 was investigated . Soluble fibronectin, which is the natural ligand for VLA-5, or mAbs against VLA-5 inhibited binding to monocytes of B . pertussis strains that express FimD but not of mutant strains that lack FimD . Beads that were coated with the fusion protein maltose-binding protein-FimD bound to adherent monocytes, and this binding was inhibited by soluble fibronectin or mAb against the alpha- or beta-chain of VLA-5, while soluble collagen or mAb against VLA-4, VLA-6, CR3, or HLA class II had no effect . Down-modulation of VLA-5 on the apical surface of monocytes by plating the cells onto surfaces precoated with anti-VLA-5 mAb also inhibited binding of beads coated with maltose-binding protein-FimD to monocytes, while precoating of the surfaces with mAb against VLA-6 or CR3 had no effect . These results indicate that VLA-5 on monocytes serves as a receptor for FimD on B . pertussis . Binding of C3bi-coated erythrocytes to monocytes, which is a measure of the binding activity of CR3, was enhanced when monocytes were adhered onto plates precoated with purified fimbriae of B . pertussis, while precoating with fimbriae lacking FimD had no effect . Precoating of the plates with FimD-containing fimbriae also enhanced binding of B . pertussis, which express FHA, but not of strains that lack FHA, to monocytes . The enhanced binding of C3bi-coated erythrocytes and B . pertussis to monocytes could be markedly inhibited by tyrphostin-47, a protein tyrosine kinase inhibitor . These results demonstrate that interaction of FimD of B . pertussis with VLA-5 on monocytes activates CR3, which requires protein tyrosine kinases and results in enhanced binding of B . pertussis to the latter receptor via FHA.

Tidsskr Nor Laegeforen, 1995 Oct 10, 115(24), 3035 - 8
{Blood transmission and infections}; Eggen BM; A blood transfusion can never become a completely risk free event . Almost all kinds of infectious agents; viruses, bacteria and parasites, can be transmitted by blood . So far, hepatitis and HIV-infections have been focused . The state of readiness to meet these infections must be kept while we prepare for "new" agents, like parvovirus B19 . Extensive international travelling will increase the possibility of blood-borne parasitic infections, like malaria and Chagas' disease, even with the very high quality demands imposed for Norwegian blood donors . We can keep a better eye on the infectivity of the blood products by strictly realizing our objective of national self-sufficiency . Recent research results indicate transfusion-mediated effects to the immune system, particularly of allogeneic transfusions containing leucocytes . This immunomodulation seems to enhance the risk of secondary infections . So far, it is impossible to tell whether this immunomodulation has any impact on the long-term outcome of malignant diseases . A blood transfusion will always represent a risk, although small, to the patient . This recognition makes it essential to carefully consider whether to give a patient a transfusion, and to document this decision properly.

Orv Hetil, 1995 Oct 8, 136(41), 2225 - 30
{Detection of Helicobacter pylori in biopsy specimens, methodical studies}; Cserni G et al.; Demonstration of Helicobacter pylori infection receives more and more importance in nowadays gastroenterological practice . The authors have compared culture and histology from 69 antral biopsy specimens for their ability to document Helicobacter pylori infection . Infection ratios in the context of clinical and histological diagnoses resulted in a distribution pattern similar to that described by others: 85-69% of duodenal ulcer patients, 67-67% of gastric ulcer patients, 62-54% of patients with gastritis and/or erosion(s) and 33-60% of endoscopically negative patients were found to be Helicobacter pylori positive with culture and histology respectively . Normal or atrophic mucosa showed no bacteria with either methods, but one must also consider the small number of such cases in this study . Chronic gastritis with no signs of activity proved to be infected only in a minority of cases, while chronic active gastritis cases were Helicobacter pylori positive in 72 and 61% histologically and with culture respectively . The modified Giemsa stain used in this study grave a relative specificity of 0.74 and sensitivity of 0.79 as compared with culture . There was a good association between the two methods tested, and this could be further improved by doing the two tests simultaneously . The association was weaker when the tests were done asynchronously, this is why it is not recommended to use such a diagnostic schedule . Comparison of the traditional haematoxylin-eosin stain with the modified Giemsa stain resulted in a very strong association between the two.(ABSTRACT TRUNCATED AT 250 WORDS)

J Biol Chem, 1995 Oct 6, 270(40), 23851 - 9
The regulatory region of calcium/calmodulin-dependent protein kinase I contains closely associated autoinhibitory and calmodulin-binding domains; Yokokura H et al.; The mechanism for the regulation of Ca2+/calmodulin-dependent protein kinase I (CaM kinase I) was investigated using a series of COOH-terminal truncated mutants . These mutants were expressed in bacteria as fusion proteins with glutathione S-transferase and purified by affinity chromatography using glutathione Sepharose 4B . A mutant (residues 1-332) showed complete Ca2+/CaM-dependent activity . Truncation mutants (residues 1-321, 1-314, and 1-309) exhibited decreasing affinities for Ca2+/CaM and also exhibited decreasing Ca2+/CaM-dependent activities . Truncation mutants (residues 1-305 or 1-299) were unable to bind Ca2+/CaM and were inactive . In contrast, truncation mutants (residues 1-293 or 1-277) were constitutively active at a slightly higher level (2-fold) than fully active CaM kinase I . These results indicate the location of the Ca2+/CaM-binding domain on CaM kinase I (residues 294-321) and predict the existence of an autoinhibitory domain near, or overlapping, the Ca2+/CaM-binding domain . These conclusions were supported by studies which showed that a synthetic peptide (CaM kinase I (294-321)) corresponding to residues 294-321 of CaM kinase I inhibited the fully active kinase in a manner that was competitive with Ca2+/CaM and also inhibited the constitutively active mutant (residues 1-293) in a manner that was competitive with Syntide-2, a peptide substrate, (Ki = 1.2 microM) but was non-competitive with ATP . Thus, these results suggest that CaM kinase I is regulated through an intrasteric mechanism common to other members of the family of Ca2+/CaM-dependent protein kinases.

J Biol Chem, 1995 Oct 6, 270(40), 23456 - 60
Evidence for a differential interaction of SHC and the insulin receptor substrate-1 (IRS-1) with the insulin-like growth factor-I (IGF-I) receptor in the yeast two-hybrid system; Tartare-Deckert S et al.; Using the yeast two-hybrid system, a genetic assay for studying protein-protein interactions, we have examined and compared the interaction of the insulin-like growth factor-I receptor (IGF-IR) and the insulin receptor (IR) with their two known substrates p52Shc and the insulin receptor substrate-1 (IRS-1) . We also mapped the specific domains of the IGF-IR and p52Shc participating in these interactions . Our findings can be summarized as follows: (i) the tyrosine kinase activity of the IGF-IR is essential for the interaction with p52Shc and IRS-1, (ii) p52Shc and IRS-1 bind to the IGF-IR in the NPEY-juxtamembrane motif, (iii) contrary to p52Shc, IRS-1 binds also to the major autophosphorylation sites (Tyr-1131, -1135, and -1136) of the IGF-IR, and (iv) the amino-terminal domain of p52Shc is required for its association with the IR and the IGF-IR . We propose that (i) the IGF-IR and the IR share at least in part the same molecular mechanism underlying their interplay with their two substrates, p52Shc and IRS-1, and (ii) IRS-1 interacts with the IGF-IR in a fashion that is different from that used by p52Shc . Finally, our data highlight the crucial role of the juxtamembrane domain in signaling by both the IR and the IGF-IR.

Biochem Biophys Res Commun, 1995 Oct 4, 215(1), 422 - 8
Cloning, subcellular localization and expression of CHL1, a subunit of magnesium-chelatase in soybean; Nakayama M et al.; Mg-insertion is the first committed step in chlorophyll synthesis and is catalyzed by Mg-chelatase . In photosynthetic bacteria, bchI gene product was suggested to be a subunit of Mg-chelatase . We isolated a bchI homolog from a soybean cDNA library and designated it as chlI . CHLI consisted of 421 amino acid residues and the sequence exhibited a high similarity to other BchI homologs . CHLI contained an ATP-binding motif found in other BchI homologs . CHLI was localized in the soluble fraction in soybean chloroplasts, suggesting that it was a stromal subunit of Mg-chelatase . chlI mRNA in cell culture (SB-P) of soybean was reversibly induced by light.

Biochemistry, 1995 Oct 3, 34(39), 12761 - 7
Secondary electron transfer processes in membranes of Heliobacillus mobilis; Lin S et al.; Picosecond transient absorption difference spectroscopic experiments were performed on membranes of the antenna/reaction center complex of Heliobacillus mobilis to study the electron transfer processes . Particular emphasis was placed on the blue spectral region, where the difference spectra of iron-sulfur centers and quinones are significantly different . Spectra were measured at room temperature in the wavelength region from 400 to 470 nm and from 630 to 730 nm . Laser excitation was into the 788 nm Q gamma band of the bacteriochlorophyll g of the reaction center complex . Global analysis in both wavelength regions reveals three kinetic components . A 25 ps phase originates from the decay of the excited state of antenna to form the primary charge-separated state P798+A0-; a 600 ps component is assigned to the electron transfer from the primary electron acceptor A0 to a secondary electron acceptor; a nondecaying component on the time scale measured represents the formation of the secondary charge-separated state . When the secondary electron acceptors were reduced by adding dithionite at pH 11, the 600 ps component disappeared . Only a 25 ps component and a constant were observed in the 630-730 nm region . The 25 ps component is assigned to the excitation decay in the antenna and the formation of P798+A0-, just as in the nonreduced sample . In the reduced sample, the P798+A0- state does not decay on the time scale measured . In the 400-470 nm region, the same kinetic behavior was observed . The absorption difference spectra of the primary and the secondary electron acceptor were constructed from different charge-separated states.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemistry, 1995 Oct 3, 34(39), 12576 - 83
Phosphorylation on threonine-18 of the regulatory light chain dissociates the ATPase and motor properties of smooth muscle myosin II; Bresnick AR et al.; We cloned the full-length cDNA for the cytoplasmic myosin II regulatory light chain (RLC) from a stage 1-2 Xenopus oocyte library . The Xenopus RLC is 94% identical to the chicken smooth muscle myosin RLC . All of the protein kinase C and myosin light chain kinase phosphorylation sites are conserved . Using trifluoperazine {Trybus, K . M., Waller, G . S., & Chatman, T . A . (1994) J . Cell Biol . 124, 963-969}, we removed the RLC of smooth muscle myosin and replaced it with recombinant Xenopus RLCs . The wild-type Xenopus RLC substitutes for the gizzard RLC in actin-activated ATPase and in vitro motility assays . We made alanine substitutions of the two residues phosphorylated by myosin light chain kinase, Ser-19 and Thr-18 . All of the myosin hybrids, regardless of their mutations or phosphorylation, have similar K+EDTA ATPase activities . As expected, the T18A, S19A hybrid had no actin-activated ATPase, whereas the T18A hybrid phosphorylated on Ser-19 had an actin-activated ATPase similar to that of wild-type hybrids phosphorylated only on Ser-19 . The actin-activated ATPase of myosin phosphorylated only on Thr-18 is approximately 15-fold lower than that of myosin phosphorylated on Ser-19 . Phosphorylation of either Ser-19 or Thr-18 permits the formation of filaments . Remarkably, in the gliding filament assay, myosin phosphorylated only on Thr-18 moves actin filaments at velocities similar to myosin phosphorylated on Ser-19 or both Thr-18 and Ser-19.

Ugeskr Laeger, 1995 Oct 2, 157(40), 5534 - 7
{Necrotizing pancreatitis}; Jakobsen HL et al.; Acute pancreatitis is in the majority of patients a mild, self-limiting illness . Five to fifteen percent of the patients develop acute necrotizing pancreatitis, a severe illness with a high morbidity and mortality . Secondary infection of the pancreatic necrosis (infected pancreatic necrosis) is the main cause of death . Pancreatic necrosis is identified with a high accuracy by contrast-enhanced computed tomography . The differentiation between sterile and infected necrosis requires demonstration of bacteria or fungi isolated from the necrosis . Surgical treatment of a sterile necrosis remains controversial, but there is a tendency towards conservative non-operative treatment . Infected pancreatic necrosis is regarded as an absolute indication for surgery, untreated the mortality is approximately 100% . The aim of modern treatment is to remove the pancreatic necrosis continuously . This has successfully been done by the open packing method, with or without subsequent drainage . At present no randomized trials comparing the different treatment modalities are available . The question of prophylactic antibiotics still remains unanswered . For the present imipenem 0,5 g x 3 is recommended.

Mol Membr Biol, 1995 Oct-Dec, 12(4), 313 - 9
Mutational analysis and molecular modelling of an amino acid sequence motif conserved in antiporters but not symporters in a transporter superfamily; Varela MF et al.; Elements of a 'G X8 G X3 G P X2 G G' amino acid sequence motif were conserved in the fifth predicted membrane-spanning domains of 31 antiporters, but none of 27 symporters or uniporters that together comprise a 'superfamily' of structurally, related transport proteins . Molecular modelling and mechanics predicted that the GP dipeptide of this motif bends the antiporters' fifth transmembrane helices, and that the repeating pattern of glycine residues forms a pocket, devoid of side chains, on the surface of these helices . The glycine residue in the motif's GP dipeptide was conserved in 90% of these antiporters with alanine being the only observed substitution . Replacement of the glycine residue of the GP dipeptide with alanine and serine reduced the level of tetracycline resistance conferred by TetA(C), a tetracycline/H+ antiporter, by 74 and 81%, respectively . All other substitutions totally abolished resistance to tetracycline . In contrast, replacement of the glycine residue of the GP dipeptide did not abolish increased susceptibility to cadmium, another phenotype conferred by TetA(C) independent of resistance to tetracycline . These results suggest that the glycine of the GP dipeptide is necessary for the tetracycline/H+ antiport activity of TetA(C), rather than its expression, stability, or general three-dimensional structure.

Mol Membr Biol, 1995 Oct-Dec, 12(4), 295 - 307
Protein transport via amino-terminal targeting sequences: common themes in diverse systems; Rusch SL et al.; Many proteins that are synthesized in the cytoplasm of cells are ultimately found in non-cytoplasmic locations . The correct targeting and transport of proteins must occur across bacterial cell membranes, the endoplasmic reticulum membrane, and those of mitochondria and chloroplasts . One unifying feature among transported proteins in these systems is the requirement for an amino-terminal targeting signal . Although the primary sequence of targeting signals varies substantially, many patterns involving overall properties are shared . A recent surge in the identification of components of the transport apparatus from many different systems has revealed that these are also closely related . In this review we describe some of the key components of different transport systems and highlight these common features.

Genetics, 1995 Oct, 141(2), 571 - 8
Evidence for an inducible repair-recombination system in the female germ line of Drosophila melanogaster . I . Induction by inhibitors of nucleotide synthesis and by gamma rays; Bregliano JC et al.; In the I-R system of hybrid dysgenesis in Drosophila melanogaster, the transposition frequency of I factor, a LINE element-like retrotransposon, is regulated by the reactivity level of the R mother . This reactivity is a cellular state maternally inherited but chromosomally determined, which has been shown to undergo heritable, cumulative and reversible changes with aging and some environmental conditions . We propose the hypothesis that this reactivity level is one manifestation of an inducible repair-recombination system whose biological role might be analogous to the SOS response in bacteria . In this paper, we show that inhibitors of DNA synthesis and gamma rays enhance the reactivity level in a very similar way . This enhancement is heritable, cumulative and reversible.

J Dairy Sci, 1995 Oct, 78(10), 2239 - 46
Influence of method of administration of rapeseed oil in dairy cows . 2 . Status of divalent cations; Ferlay A et al.; The effects of method of administration of rapeseed oil on total, soluble, and ionizable Ca and Mg in ruminal fluid were determined for four diary cows fed a basal diet without (control) or with rapeseed oil (1 kg/d) added by continuous infusion or by a single administration via the ruminal cannula . The control diet contained 68% forage and 32% concentrate mix (DM basis) . Fatty acid, Ca, and Mg contents, respectively, were 1.78, 1.16, and .47% for the control diet and 7.38, 1.05, and .44% for the supplemented diets . Soluble and ionizable Ca and Mg concentrations of ruminal fluid and the total Ca, Mg, and soaps of fatty acids in ruminal contents were determined over 24 h . All concentrations except total Ca varied with sampling time . All contents of soluble and ionizable Ca were decreased by lipid supplementation . A lack of ionizable Ca may limit the attachment of bacteria to particles, thus reducing ruminal digestion . In contrast, variations of Mg from lipid supply were lower than those of Ca . The interaction between time and diet was significant for soluble and ionizable Ca contents of ruminal fluid . Diurnal variation of these components was not associated with variations in the estimated soaps of fatty acids.

J Dairy Sci, 1995 Oct, 78(10), 2186 - 95
Factors affecting herd milk composition and milk plasmin at four levels of somatic cell counts; Ballou LU et al.; A longitudinal study was carried out on samples of bulk tank milk collected from 200 farms for 12 mo to evaluate SCC, plasmin and plasminogen activities, psychrotrophic bacteria count, and protein quality in milk and to examine the proteolytic effects of plasmin on milk proteins . Herds were selected randomly from client lists of two dairies to create four groups based on milk SCC of the month before the study; herds were reassigned monthly to one of four groups based on SCC for that month . Overall means were 3.73% fat, 3.13% protein by infrared analysis, 3.16% protein by Kjeldahl analysis, 2.42% casein percentage, 4.65% lactose, 5.43 cells/ml of log SCC, 1.13 U of plasmin, 45.6 U of plasminogen, and log 2.86 cfu/ml of psychrotrophic bacteria . The ANOVA showed a significant effect of month on all factors except SCC, which was fixed by the experimental design . Plasmin and plasminogen activities were high from December to May . Plasmin activities and psychrotroph counts were significantly higher for the high SCC group . Casein percentage and number were significantly higher for the low SCC group.

Mol Microbiol, 1995 Oct, 18(1), 115 - 21
Identification of a methyl-accepting chemotaxis protein in Rhodobacter sphaeroides; Ward MJ et al.; Analysis of the DNA sequence directly upstream of the chemotaxis operon of Rhodobacter sphaeroides identified a single gene whose product has strong similarity to the methyl-accepting chemotaxis proteins (MCPs) found in enteric bacteria . The deduced protein had a highly conserved signalling sequence and only one very hydrophobic region at the N-terminus, in contrast to enteric MCPs . A possible cytoplasmic location of the majority of the protein was supported by Western blotting . The mcpA gene was insertionally inactivated and the resulting phenotype examined using swarm plate assays . The mutant lacking McpA lost chemotaxis to a wide range of attractant stimuli but only under aerobic conditions; it retained almost normal chemotaxis under anaerobic/photosynthetic conditions . The identification of a sensory protein which is active only under one set of growth conditions suggests that R . sphaeroides probably has several MCPs, which co-ordinately respond to changes in environmental conditions . Southern hybridization at relaxed stringency to the conserved sequence of the R . sphaeroides and Caulobacter crescentus mcp genes identified three possible additional mcp genes.

Environ Health Perspect, 1995 Oct, 103 Suppl 7, 103 - 12
Phytoestrogens: epidemiology and a possible role in cancer protection; Adlercreutz H; Because many diseases of the Western Hemisphere are hormone-dependent cancers, we have postulated that the Western diet, compared to a vegetarian or semivegetarian diet, may alter hormone production, metabolism, or action at the cellular level by some biochemical mechanisms . Recently, our interest has been mainly focused on the cancer-protective role of some hormonelike diphenolic phytoestrogens of dietary origin, the lignans and the isoflavonoids . The precursors of the biologically active compounds originate in soybean products (mainly isoflavonoids), whole grain cereal food, seeds, and probably berries and nuts (mainly lignans) . The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormonelike compounds with weak estrogenic but also antioxidative activity; they have now been shown to influence not only sex hormone metabolism and biological activity but also intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation, and angiogenesis in a way that makes them strong candidates for a role as natural cancer-protective compounds . Epidemiologic investigations strongly support this hypothesis because the highest levels of these compounds in the diet are found in countries or regions with low cancer incidence . This report is a review on recent results suggesting that the diphenolic isoflavonoids and lignans are natural cancer-protective compounds.

Farmaco, 1995 Oct, 50(10), 689 - 95
Synthesis and pharmacological evaluation of thieno{2,3-d}pyrimidin-2,4-dione and 5H-pyrimido {5,4-b}indol-2,4-dione derivatives; Santagati NA et al.; Two series of novel derivatives based on the thienopyrimidine and pyrimidoindole ring systems, both N-substituted in position 3, have been synthesized . The compounds were obtained by reaction of N-amino groups of 5,6-dimethyl-thieno{2,3-d}pyrimidin-2,4-dione and of 5H-pyrimido{5,4-b}indol-2,4-dione with aromatic aldehydes . Some of these substances showed an appreciable analgesic activity, a good antiinflammatory activity, a low acute toxicity with an optimal gastric tolerance.

Vaccine, 1995 Oct, 13(14), 1263 - 76
Adjuvants for human vaccines--current status, problems and future prospects; Gupta RK et al.; Adjuvants help antigen to elicit an early, high and long-lasting immune response with less antigen, thus saving on vaccine production costs . In recent years, adjuvants received much attention because of the development of purified, subunit and synthetic vaccines which are poor immunogens and require adjuvants to evoke the immune response . With the use of adjuvants immune response can be selectively modulated to major histocompatibility complex (MHC) class I or MHC class II and Th1 or Th2 type, which is very important for protection against diseases caused by intracellular pathogens such as viruses, parasites and bacteria (Mycobacterium) . A number of problems are encountered in the development and use of adjuvants for human vaccines . The biggest issue with the use of adjuvants for human vaccines, particularly routine childhood vaccines, is the toxicity and adverse side-effects of most of the adjuvant formulations . At present the choice of adjuvants for human vaccination reflects a compromise between a requirement for adjuvanticity and an acceptable low level of side-effects . Other problems with the development of adjuvants include restricted adjuvanticity of certain formulations to a few antigens, use of aluminum adjuvants as reference adjuvant preparations under suboptimal conditions, non-availability of reliable animal models, use of non-standard assays and biological differences between animal models and humans leading to the failure of promising formulations to show adjuvanticity in clinical trials . The most common adjuvants for human use today are still aluminum hydroxide and aluminum phosphate, although calcium phosphate and oil emulsions also have some use in human vaccinations . During the last 15 years much progress has been made on development, isolation and chemical synthesis of alternative adjuvants such as derivatives of muramyl dipeptide, monophosphoryl lipid A, liposomes, QS21, MF-59 and immunostimulating complexes (ISCOMS) . Other areas in adjuvant research which have received much attention are the controlled release of vaccine antigens using biodegradable polymer microspheres and reciprocal enhanced immunogenicity of protein-polysaccharide conjugates . Biodegradable polymer microspheres are being evaluated for targeting antigens on mucosal surfaces and for controlled release of vaccines with an aim to reduce the number of doses required for primary immunization . Reciprocal enhanced immunogenicity of protein-polysaccharide conjugates will be useful for the development of combination vaccines.

J Hematother, 1995 Oct, 4(5), 377 - 82
Alternative triggering molecules and single chain bispecific antibodies; Segal DM et al.; Although T cell receptors and Fc receptors are the best known cytotoxic triggering molecules, a number of adhesion molecules recently have been identified as alternative triggering molecules . We discuss how CD44, an adhesion molecule found on all leukocytes and many other cell types, becomes a triggering molecule on NK cells following stimulation with IL-2 . We also describe a genetically engineered single chain bispecific antibody, produced in mammalian cells and in bacteria, that is capable of redirecting lysis in the nanogram per milliliter range.

Semin Immunol, 1995 Oct, 7(5), 307 - 19
The TCR-beta chain repertoire of gut-derived T lymphocytes; Regnault A et al.; The gastrointestinal tract represents a natural barrier to environmental pathogens . The gut-associated lymphoid tissue (GALT) provides protection and interacts with the external environment, e.g . bacteria and food antigens . Large numbers of leukocytes are present as aggregates in the lymphoid follicles and as single cells in the lamina propria and epithelium . Intraepithelial T lymphocytes are localized within the tight junctions between epithelial cells . In conventional adult mice, they mainly express CD8, with half of the cells expressing the common CD8 molecule, the CD8 alpha beta heterodimer and the other half expressing a homodimer CD8 alpha alpha . The CD8 alpha beta IEL bear a TcR alpha beta while CD8 alpha alpha bear either a TcR gamma delta or a TcR alpha beta . Studies of repertoire with human IEL cell lines and with total human IEL population showed that both the alpha-chain and the beta-chain repertories are oligoclonal . Our own results of the analysis of repertoire diversity in genetically identical mice raised the same environment have shown that both CD8 alpha alpha and CD8 alpha beta TcR alpha beta IEL populations express a distinct oligoclonal repertoire that differs from one individual to the next . Compared to the lymph node lymphocytes, both IEL populations are composed of a very limited number of clones that undergo clonal expansion . Furthermore, the study of repertoire throughout the length of the small intestine has revealed that some of the clones are present all along the epithelium suggesting that the CD8 alpha alpha IEL and CD8 alpha beta IEL are capable of recirculating or migrating in the intestine . We propose that the repertoire of TcR alpha beta IEL is derived from a restricted number of T cells that either develop in situ or that arrive through circulation and can then undergo clonal expansion.

Int J Clin Pharmacol Ther, 1995 Oct, 33(10), 537 - 9
Aminoglycoside pharmacokinetics and -dynamics: a nonlinear approach; Czock D et al.; A model which correctly describes the pharmacokinetic-pharmacodynamic relationship is necessary to perform a rational pharmacotherapy . This model could predict the effects under variable conditions . The prediction will provide a basis for adapting therapy to individuals . A nonlinear model should be most appropriate for describing drug effects . A new model, containing nonlinear pharmacokinetics and pharmacodynamics, is presented to describe effects of aminoglycosides on bacterial growth and accumulation in kidney tissue.

J Clin Microbiol, 1995 Oct, 33(10), 2752 - 6
Diagnosis of Helicobacter pylori infection by PCR: comparison with other invasive techniques and detection of cagA gene in gastric biopsy specimens; Lage AP et al.; A PCR assay for the detection of Helicobacter pylori in gastric biopsy specimens with specific primers for ureC gene amplification (herein referred to as ureC PCR) was compared with other routine invasive methods (culture, the rapid-urease test, and Giemsa staining of histological sections) with samples from a group of 104 consecutive dyspeptic patients . Bacteria were found in 40 (38.5%), 38 (36.5%), 36 (34.6%), and 35 (33.7%) of the patients by ureC PCR, culture, the rapid-urease test, and Giemsa stain, respectively . Sixty-three patients had negative cultures, negative histological examinations, and negative rapid-urease test results, and 61 of these patients were also negative by ureC PCR . ureC PCR detected H . pylori in two culture-negative patients . In parallel, a PCR-based assay to detect the H . pylori cytotoxin-associated antigen (cagA) gene, a putative virulence gene, was also developed . To assess the likelihood of detection of H . pylori genes directly from gastric biopsy samples and from the corresponding H . pylori isolates, specimens from 31 patients were subjected to PCR with ureC- and cagA-targeting primers . All 31 biopsy specimens and the corresponding H . pylori isolates were positive in the ureC PCR . H . pylori strains that were cagA positive also gave positive cagA PCR fragments with biopsy specimens from the same patients . All ureC PCR-positive patients were examined; biopsy specimens from 10 of 11 (91.7%) duodenal ulcer patients harbored H . pylori cagA-positive strains, whereas 19 of26 (73%) of those from patients with chronic gastritis only were found to be cagA positive . These findings indicate first that ureC PCR is at least as sensitive as culture for diagnosing H . pylori infection and second that the presence of the H . pylori cagA gene can also be detected directly in biopsy specimens by PCR amplification.

C R Acad Sci III, 1995 Oct, 318(10), 1053 - 7
{Free diaminopimelic acid of symbiotic bivalves}; Alberic P et al.; Free amino acids were analyzed in tissues of symbiotic bivalves from hydrothermal vent sites at Galapagos rift, and cold-seeps in Japan trench and Barbados subduction area . Diaminopimelic acid (a fragment of the bacterial cell wall mureid complex) is, in some cases, one of the most abundant compounds . It's presence in the tissues of the bivalves is related to exchanges between host and symbionts . Diaminopimelate concentration differences among species may correspond to both taxonomic bacterial differences and different carbon translocation processes from bacteria to host . Variation among individuals may correspond to fluctuation of micro-environmental conditions.

Mol Biotechnol, 1995 Oct, 4(2), 167 - 78
The commercial and agricultural applications of animal transgenesis; Ward KA et al.; The potential for commercial application of transgenic technologies in domestic animals is discussed in relation to the areas where a significant impact on agriculture might be expected . These are the endocrine system, novel biochemical pathways, structural proteins of milk and of textile fibers, and the immune system . Manipulation of the endocrine system has been investigated for some years and it is clear that very accurate control is needed over gene expression if this approach is to prove commercially useful . The area most advanced in commercial application is the production of high-value pharmaceutical proteins in the mammary glands of domestic animals . Other applications that are discussed remain to be proven in larger animals despite being demonstrated laboratory test animals . These include a functional cysteine biosynthetic pathway and a functional glyoxylate cycle transferred from bacteria to mice, and alterations to the proteins of hair that change the physical properties of the resultant fibers . Research is also actively directed toward novel approaches for providing domestic animals with resistance to insects.

Arch Pharm (Weinheim), 1995 Oct, 328(10), 705 - 8
Synthesis of new 2-({(phenoxy or phenyl)acetyl}amino)benzoic acid derivatives as 3 alpha-hydroxysteroid dehydrogenase inhibitors and potential antiinflammatory agents; Daidone G et al.; A number of 2-({(phenoxy or phenyl)acetyl}amino)benzoic acid derivatives were prepared in about 50% yield from (phenoxy or phenyl)acetyl chloride and anthranilic acid derivatives . All the compounds were tested as in vitro inhibitors of 3 alpha-hydroxysteroid dehydrogenase, since enzyme inhibition predicts potential antiinflammatory activity in vivo . The most active compounds 3 l, m, s are about 3.5 times more active than acetylsalicylic acid (ASA) . Activity is influenced by electronic as well as steric effects.

J Clin Pathol, 1995 Oct, 48(10), 912 - 4
Detection of bacteraemia by the continuously monitoring BacT/Alert system; Kennedy GT et al.; AIMS--To analyse a continuously monitoring blood culture system with respect to the time to detection of various groups of organisms, their clinical importance, and the relative efficacy of the aerobic and anaerobic bottles . METHODS--Four thousand blood cultures were monitored and the information relating to the positive cultures was noted and analysed . RESULTS--Four hundred and seventy seven blood cultures were detected as positive, 81% (387/477) of which were detected within 48 hours . The most pathogenic organisms were detected in the shortest period, less pathogenic later and those generally regarded as contaminants last . Clinically important isolates were also detected earlier . Many positive blood cultures were detected in only one bottle of the set, even those regarded as clinically important . CONCLUSIONS--The management of continuously monitoring blood culture systems could be improved by considering time to detection trends . Clinicians should be aware of the relatively rapid detection of clinically important, positive blood cultures in relation to patient treatment.

J Trop Pediatr, 1995 Oct, 41(5), 258 - 66
Genital infections in the aetiology of late fetal death: an incident case-referent study; Osman NB et al.; Women with prelabour fetal death in the third trimester were recruited in order to study the association between intra-uterine death and maternal genital colonization of bacteria . Fifty-eight women with verified fetal death were compared with a group of 58 women matched for age, parity and gestational length (the first referent group) and with women delivering liveborn neonates (second referent group) . Cultures from the vagina, the endocervix, the amniotic fluid, the placenta, the conjunctivae of the newborn and the secretion of gastric aspirate of the newborn were carried out . Blood was taken for haemoglobin, thick film (malaria) and syphilis and HIV serology . Cases were more affected by previous stillbirths than first referents (OR = 11.88) . Preterm delivery was significantly more common in cases than in second referents (OR = 57.70) . Cases had significantly more often < 3 ANC visits (OR = 2.81) . Cases had a lower body mass index than first referents (OR = 2.38) . Temperature > or = 37 degrees C was 12 times more frequent in cases than in first referents (OR = 21.20) and four times more frequent than in second referents (OR = 6.60) . Average birth weight among stillborns was 1954 g and in liveborns 3223 g (P = 0.001) . The corresponding prevalence of LBW was 78% in cases and 0% among second referents (P < 0.001) . Histological chorioamnionitis was significantly prevalent in cases than in second referents (OR = 4.97) . Syphilis was significantly more common in cases than in first (OR = 7.71) and in second referents (OR = 5.30).(ABSTRACT TRUNCATED AT 250 WORDS)

Arch Oral Biol, 1995 Oct, 40(10), 913 - 20
Effects of chlorhexidine on human taste perception; Helms JA et al.; Chlorhexidine gluconate at a dose used to control bacteria in the mouth has a reversible effect on taste perception . Taste-intensity ratings and taste-quality identification for concentration series of sucrose, sodium chloride, citric acid and quinine hydrochloride were obtained from 15 healthy humans . The participants rinsed with 0.12% chlorhexidine for 3 min twice a day . Each individual was tested 3 times: before the 4-day rinse period, 30 min after the final rinse, and 4 days after the rinse period . Chlorhexidine rinses reduced the perceptual intensity of sodium chloride and quinine hydrochloride, not sucrose or citric acid . No effects on taste perception were detected 4 days after the rinse period . The identification of sodium chloride as salty was seriously impaired by chlorhexidine but the identification of quinine hydrochloride as bitter was not affected . Specific sites of action of chlorhexidine on the taste epithelium are not known but its effects on salty taste may be related to its strong positive charge and its effect on bitter taste may be related to its amphiphilicity . Chlorhexidine has promise as a probe of taste transduction, as well as for the management of salty/bitter dysgeusias in humans.

Ann Occup Hyg, 1995 Oct, 39(5), 591 - 601
Acetic aldehyde and formaldehyde in cutting fluids and their relation to irritant symptoms; Jarvholm B et al.; The objective was to study the formation of acetic aldehyde in cutting fluids and its relation to irritation of mucous membranes and the skin . Acetic aldehyde and formaldehyde were analysed in two large cutting fluid systems in an engineering industry . Samples were taken 1-5 times a week during a year . Concentration of the cutting fluid, leakage oils, pH, bacteria, yeast and fungi were analysed weekly . The occurrence of mucous membrane irritation was registered through questionnaires to the exposed workers . About 50 persons were exposed to each of the cutting fluids . The concentration of the aldehydes varied with time and between the cutting fluids . None of the analysed parameters could explain the variable concentration of aldehydes . Mucous membrane irritation was much more common in one of the systems, e.g . the prevalence of irritation in the nose was about 30-40% in workers exposed to a cutting fluid, while the corresponding prevalence was less than 10% in workers exposed to another fluid . The occurrence of symptoms was slightly associated with the concentration of aldehydes and pH of the fluid varied more in the fluid that caused most symptoms . A few measurements of ammonia indicated a higher concentration of ammonia in the fluid that caused most symptoms . It is concluded that irritation of mucous membranes and the skin may vary considerably between different cutting fluids of similar composition and use but the causal factor could not be determined in this study, but a variable pH and an increased concentration of ammonia may be indicators in this context . The concentration of acetic aldehyde vary with time and between cutting fluids with similar composition . A high variability may be an indicator of less stable cutting fluids . Better markers for the surveillance of cutting fluids needs to be developed as well as a health control programme.

J Cardiovasc Surg (Torino), 1995 Oct, 36(5), 515 - 7
Delayed postpneumonectomy empyema; Schueckler OJ et al.; OBJECTIVE . Most postpneumonectomy empyemas occur shortly after the surgery, but rarely do they manifest much later . We present our experience in treating two cases of delayed postpneumonectomy empyema and discuss its clinical features . EXPERIMENTAL DESIGN . The diagnosis of delayed empyema is difficult as patients present with nonspecific symptoms . Consequently, there was a delay of several weeks in reaching the correct diagnosis . This is a retrospective case study of two patients . SETTING . The patients were admitted to hospital for appropriate care . PATIENTS . Two patients were diagnosed as having delayed postpneumonectomy empyema from consequential infection . Chest X-ray may provide helpful information such as the presence of air-fluid level or a mediastinal shift toward the remaining lung (by accumulation of pus in the postpneumonectomy cavity) . INTERVENTION . The patients were treated surgically . RESULTS . In both cases the diagnosis of postpneumonectomy empyema was delayed, but eventually correct diagnosis was made . The outcome of the surgical therapy was successful . CONCLUSIONS . Delayed postpneumonectomy empyema is a rare condition . The etiology in the majority of cases is probably due to hematogenous spread of bacteria from other parts of the body . Correct diagnosis of this condition is often delayed . The treatment is surgical.

An Med Interna, 1995 Oct, 12(10), 477 - 84
{Descriptive study of 39 cases of hepatic abscess of pyogenic and amebic origin}; Blanco Quintana F et al.; Thirty nine cases of liver abscess--33 pyogenic (LAP) and 6 amebic (LAA)--attended in our hospital between 1980 and 1994, were reviewed . Mean patient age was 55.66 years (LAP) and 35.83 years (LAA), while the relation male/female was 2.3:1 and 5:1 respectively . The most usual underlying pathology in LAP was bile duct disease (39.39%) . Four patients with LAA had travelled to endemic areas . Fever was the most frequent clinical finding (71.79%) . Echography and/or CT scan confirmed the diagnosis in 32 patients (82.05%), with a sensitivity of 86.66 and 95.65% respectively . Positive cultures were found in 74.35% (39.13% polymicrobials), being E . Coli and K . Pneumoniae the most frequently isolated bacteria . In LAP pus cultures were positive in 73% and blood cultures in 55% . Diagnosis of LAA was made by wet mount smears/serology (3/3) . Percutaneous drainage was performed in 41.02%, surgical drainage in 48.71 and 15.38% (all with LAP) received antibiotics exclusively . Four patients died (3 with LAP and 1 with LAA).

J Virol, 1995 Oct, 69(10), 6376 - 88
Vaccinia virus morphogenesis is blocked by temperature-sensitive mutations in the F10 gene, which encodes protein kinase 2; Wang S et al.; Four previously isolated temperature-sensitive (ts) mutants of vaccinia virus WR (ts28, ts54, ts61, and ts15) composing a single complementation group have been mapped by marker rescue to the F10 open reading frame located within the genomic HindIII F DNA fragment . Sequencing of the F10 gene from wild-type and mutant viruses revealed single-amino-acid substitutions in the F10 polypeptide responsible for thermolabile growth . Although the ts mutants displayed normal patterns of viral protein synthesis, electron microscopy revealed a profound morphogenetic defect at the nonpermissive temperature (40 degrees C) . Virion assembly was arrested at an early stage, with scant formation of membrane crescents and no progression to normal spherical immature particles . The F10 gene encodes a 52-kDa serine/threonine protein kinase (S . Lin and S . S . Broyles, Proc . Natl . Acad . Sci . USA 91:7653-7657, 1994) . We expressed a His-tagged version of the wild-type, ts54, and ts61 F10 polypeptides in bacteria and purified these proteins by sequential nickel affinity and phosphocellulose chromatography steps . The wild-type F10 protein kinase activity was characterized in detail by using casein as a phosphate acceptor . Whereas the wild-type and ts61 kinases displayed similar thermal inactivation profiles, the ts54 kinase was thermosensitive in vitro . These findings suggest that protein phosphorylation plays an essential role at an early stage of virion assembly.

J Bacteriol, 1995 Oct, 177(20), 6018 - 20
Hydrogenase does not confer significant benefits to Azotobacter vinelandii growing diazotrophically under conditions of glucose limitation; Linkerhagner K et al.; The presumed beneficial effect of hydrogenase on growth of diazotrophic bacteria was reinvestigated with carbon-limited chemostat cultures of the hydrogenase-deficient mutant hoxKG of Azotobacter vinelandii and its parent . The results revealed that hydrogen recycling was too low to benefit the cellular energy metabolism or activities of nitrogenase and respiration.

J Bacteriol, 1995 Oct, 177(20), 5853 - 9
Electron transport-dependent taxis in Rhodobacter sphaeroides; Gauden DE et al.; Rhodobacter sphaeroides showed chemotaxis to the terminal electron acceptors oxygen and dimethyl sulfoxide, and the responses to these effectors were shown to be influenced by the relative activities of the different electron transport pathways . R . sphaeroides cells tethered by their flagella showed a step-down response to a decrease in the oxygen or dimethyl sulfoxide concentration when using them as terminal acceptors . Bacteria using photosynthetic electron transport, however, showed a step-down response to oxygen addition . Addition of the proton ionophore carbonyl cyanide 4-trifluoromethoxyphenylhydrazone did not cause a transient behavioral response, although it decreased the electrochemical proton gradient (delta p) and increased the rate of electron transport . However, removal of the ionophore, which caused an increase in delta p and a decrease in the electron transport rate, resulted in a step-down response . Together, these data suggest that behavioral responses of R . sphaeroides to electron transport effectors are caused by changes in the rate of electron transport rather than changes in delta p.

J Bacteriol, 1995 Oct, 177(20), 5812 - 7
Phosphorylation of the PII protein (glnB gene product) in the cyanobacterium Synechococcus sp . strain PCC 7942: analysis of in vitro kinase activity; Forchhammer K et al.; The PII protein in the cyanobacterium Synechococcus sp . strain PCC 7942 signals the cellular state of nitrogen assimilation relative to CO2 fixation by being phosphorylated at a seryl residue . In this study, we first determined the location of the phosphorylated seryl residue within the PII amino acid sequence . The phosphorylation site exhibits an RXS motif, a recognition sequence characteristic for cyclic AMP-dependent protein serine kinases from eukaryotes . We established an in vitro PII phosphorylation assay to further analyze the PII kinase activity in Synechococcus sp . strain PCC 7942 . ATP was used specifically as a phosphoryl donor, and the PII kinase activity was shown to be stimulated by alpha-ketoglutarate . Unlike the PII-modifying uridylyltransferase- and uridylyl-removing enzyme characterized in proteobacteria, the activity of the PII kinase from the cyanobacterium did not respond to glutamine.

Immunity, 1995 Oct, 3(4), 495 - 507
Direct presentation of nonpeptide prenyl pyrophosphate antigens to human gamma delta T cells; Morita CT et al.; Human V gamma 2V delta 2+ T cells recognize mycobacterial nonpeptide antigens, such as isopentenyl pyrophosphate, and their synthetic analogs, such as monoethyl phosphate, through a TCR-dependent process . Here, we examine the presentation of these antigens . V gamma 2V delta 2+ T cells recognized secreted prenyl pyrophosphate antigens in the absence of other accessory cells but, under such conditions, required T cell-T cell contact . Recognition required neither the expression of classical MHC class I, MHC class II, or CD1a, CD1b, and CD1c molecules, nor MHC class I or class II peptide loading pathways . Fixed accessory cells also presented the prenyl pyrophosphate antigens to gamma delta T cells . Thus, in contrast with the presentation of conventional peptide antigens, protein antigens, and superantigens to alpha beta T cells, prenyl pyrophosphate antigens are presented to gamma delta T cells through a novel extracellular pathway that does not require antigen uptake, antigen processing, or MHC class I or class II expression . This pathway allows for the rapid recognition of bacteria by gamma delta T cells and suggests that gamma delta T cells play a role in the early response to bacterial infection.

Microbiology, 1995 Oct, 141 ( Pt 10), 2529 - 34
Response of the bvg regulon of Bordetella pertussis to different temperatures and short-term temperature shifts; Prugnola A et al.; Bordetella pertussis produces a number of virulence factors whose expression is coordinately regulated by the bvgAS locus . Transcription of virulence genes is repressed by environmental factors such as low temperature (25 degrees C) and chemical stimuli . Temperature shift of bacterial cultures from 25 degrees C to 37 degrees C activates two classes of bvg-regulated virulence genes: the early genes, which are activated within 10 min, and late genes, which require 2-4 h for activation . During the interval between the activation of the early and late genes, the intracellular concentration of BvgA increases 50-fold . It has been proposed that this increased concentration may be required for the activation of the late genes . Here we have analysed the response of the bvg locus to intermediate temperature and to repeated temperature shifts . Temperature shifts of B . pertussis cultures from 22 degrees C to 28 degrees C or 35 degrees C resulted in the synthesis of low, intermediate, and high amounts of BvgA . This implied that the intracellular concentration of BvgA is temperature-dependent . We have also observed that the amount of virulence factors produced correlates with the BvgA concentration . When bacteria grown at 37 degrees C were shifted to 22 degrees C, transcription from the adenylate cyclase toxin haemolysis promoter (PAC) was repressed after 30 min, while transcription from the bvg (P1) and filamentous haemagglutinin (PFHA) promoters was repressed after 2 h . During this time, the amount of BvgA did not decrease.(ABSTRACT TRUNCATED AT 250 WORDS)

Lett Appl Microbiol, 1995 Oct, 21(4), 257 - 60
Effect of freezing of water samples on viable counts of environmental mycobacteria; Iivanainen E et al.; The effect of prolonged storage on mycobacteria and other heterotrophic bacteria in brook water samples was examined by determination of viable counts from fresh samples and again after water concentrates had been stored in nutrient broth at -75 degrees C for 15 months . The counts of mycobacteria were on average three times higher after storage (range of ratio 0.9-10.4) . In contrast, the viable counts of other heterotrophic bacteria were reduced by 69% . The increase in mycobacterial counts was probably due to break-up of microcolonies or release of attached bacteria from particles . The possibility of cultivating mycobacteria from frozen samples is of practical help in large-scale field surveys.

Lett Appl Microbiol, 1995 Oct, 21(4), 230 - 4
The importance of methanogens associated with ciliate protozoa in ruminal methane production in vitro; Newbold CJ et al.; The importance of methanogenic bacteria associated with ciliate protozoa was estimated either by removing protozoa from whole rumen fluid (using defaunated rumen fluid to correct for the effects of centrifugation on bacteria) or by isolating the protozoa . Rumen fluid was withdrawn from sheep inoculated with either Polyplastron multivesiculatum, a co-culture of Isotricha prostoma plus Entodinium spp . or a mixed type B fauna of Entodinium, Eudiplodinium and Epidinium spp . Methanogenesis was highest in rumen fluid containing a mixed protozoal population of the following genera: Entodinium, Eudiplodinium and Epidinium, was lower in defaunated rumen fluid and lowest in rumen fluid containing either I . prostoma plus Entodinium or P . multivesiculatum . Methanogenic bacteria associated with rumen ciliates were apparently responsible for between 9 and 25% of methanogenesis in rumen fluid.

Am J Gastroenterol, 1995 Oct, 90(10), 1868 - 70
Eosinophilic gastroenteritis involving the entire digestive tract; Matsushita M et al.; Eosinophilic gastroenteritis, an inflammatory disease of unknown etiology, commonly involves the stomach and small intestine with eosinophilic infiltration . Herein we describe an unusual case of eosinophilic gastroenteritis involving the entire digestive tract . A 24-yr-old woman came to our hospital presenting with diarrhea with marked peripheral eosinophilia . Stool specimens were negative for parasites, ova, bacteria, and fungi . Barium and endoscopic studies showed thickened edematous folds of the duodenum and small intestine . Biopsy specimens of the esophagus, stomach, duodenum, ileum, and colon showed eosinophilic infiltration . A diagnosis of eosinophilic gastroenteritis involving the entire digestive tract was made, and therapy with prednisone was started . Symptoms and peripheral eosinophilia rapidly resolved, and biopsies of the digestive tract demonstrated no eosinophilic infiltration . This case illustrates the expanded spectrum of the disease to the entire digestive tract and emphasizes the diagnostic usefulness of endoscopic biopsies . The initial presentation of patients with eosinophilia requires the evaluation of the entire digestive tract . It is worth noting that eosinophilic gastroenteritis can involve the entire digestive tract.

Am J Gastroenterol, 1995 Oct, 90(10), 1829 - 33
Electron microscopic study of association between coccoid forms of Helicobacter pylori and gastric epithelial cells; Janas B et al.; OBJECTIVE: To investigate the relationship between helical and coccoid forms of Helicobacter pylori and gastric epithelial cells . METHODS: Gastric antral and body biopsies were obtained from eight children, aged 10-17 yr, who underwent diagnostic gastroscopy . Specimens were processed for electron microscopy . The location of organisms and ultrastructural features were assessed with a transmission electron microscope . RESULTS: We observed two morphological forms of bacteria in three of eight H . pylori-positive patients . Helical forms were localized only in the proximity to unchanged or variously damaged mucous cells, but coccoid forms were present only above strongly damaged epithelial cells . CONCLUSION: Coccoid forms of H . pylori are closely associated with damaged gastric mucous cells . Possible explanations for this phenomenon are discussed.

Mol Cell Biol, 1995 Oct, 15(10), 5820 - 9
Correlation of two-hybrid affinity data with in vitro measurements; Estojak J et al.; Since their introduction, the interaction trap and other two-hybrid systems have been used to study protein-protein interactions . Despite their general use, little is known about the extent to which the degree of protein interaction determined by two-hybrid approaches parallels the degree of interaction determined by biochemical techniques . In this study, we used a set of lexAop-LEU2 and lexAop-lacZ reporters to calibrate the interaction trap . For the calibration, we used two sets of proteins, the Myc-Max-Mxi1 helix-loop-helix proteins, and wild-type and dimerization-defective versions of the lambda cI repressor . Our results indicate that the strength of interaction as predicted by the two-hybrid approach generally correlates with that determined in vitro, permitting discrimination of high-, intermediate-, and low-affinity interactions, but there was no single reporter for which the amount of gene expression linearly reflected affinity measured in vitro . However, some reporters showed thresholds and only responded to stronger interactions . Finally, some interactions were subject to directionality, and their apparent strength depended on the reporter used . Taken together, our results provide a cautionary framework for interpreting affinities from two-hybrid experiments.

J Cell Physiol, 1995 Oct, 165(1), 54 - 61
Chondroitin sulfate proteoglycan modulates the permeability of hyaluronan-containing coats around normal human mesothelial cells; Heldin P et al.; The composition and permeability of the pericellular coat surrounding normal human mesothelial (NHM) cells have been studied in vitro . NHM cells were grown in the presence of 3H-glucosamine and the amount of label recovered in hyaluronan and chondroitin sulfate was determined after selective enzymatic digestion of the polysaccharides in medium, pericellular, and intracellular pools . For comparison a similar analysis was carried out on mesothelioma cells (Mero-14) . Of the labeled polysaccharides in the medium and pericellular pools of NHM cells about 80-90% could be ascribed to hyaluronan and only 3-5% to chondroitin sulfate . In contrast, Mero-14 synthesized only minute amounts of hyaluronan whereas chondroitin sulfate corresponded to 61% of the total glycosaminoglycans in the culture . The results exclude a structure of the pericellular layer of NHM cells similar to the hyaluronan-proteoglycan aggregates found in cartilage . The permeability of the pericellular layer was tested by the exclusion of polystyrene microspheres and bacteria of diameter 0.1-3.0 microns, as well as erythrocytes of diameter 7 microns . While the erythrocytes were excluded the smaller particles penetrated the coat . By adding 0.5 mg/ml of aggregating cartilage proteoglycan to the medium particles of 0.3 microns or larger were also excluded . Thus exogenous proteoglycans can reinforce the structure of the pericellular layer.

J Cell Biol, 1995 Oct, 131(1), 165 - 78
Anillin, a contractile ring protein that cycles from the nucleus to the cell cortex; Field CM et al.; We report the cDNA sequence and localization of a protein first identified by actin filament chromatography of Drosophila embryo extracts as ABP8 (Miller, K . G., C . M . Field, and B . M . Alberts . 1989 . J . Cell Biol . 109:2963-2975) . The cDNA encodes a 1201-amino acid protein which we name anillin . Anillin migrates at 190 kD on SDS-PAGE . Anillin is expressed throughout Drosophila development and in tissue culture cells . By immunofluorescence, anillin localizes to the nucleus of interphase cells, except in the syncytial embryo where it is always cytoplasmic . During metaphase, it is present in the cytoplasm and cortex, and during anaphase-telophase it becomes highly enriched in the cleavage furrow along with myosin II . In the syncytial embryo, anillin, along with myosin-II, is enriched in cortical areas undergoing cell cycle regulated invagination including metaphase furrows and the cellularization front . In contractile rings, metaphase furrows, and nascent ring canals, anillin remains bound to the invaginated cortex suggesting a stabilizing role . Anillin is not expressed in cells that have left the cell cycle . Anillin isolated from embryo extracts binds directly to actin filaments . The domain responsible for this binding has been mapped to a region of 244 amino acids by expression of protein fragments in bacteria . This domain, which is monomeric in solution, also bundles actin filaments . We speculate that anillin plays a role in organizing and/or stabilizing the cleavage furrow and other cell cycle regulated, contractile domains of the actin cytoskeleton.

Infect Immun, 1995 Oct, 63(10), 3878 - 85
Porphyromonas gingivalis invasion of gingival epithelial cells; Lamont RJ et al.; Porphyromonas gingivalis, a periodontal pathogen, can invade primary cultures of gingival epithelial cells . Optimal invasion occurred at a relatively low multiplicity of infection (i.e., 100) and demonstrated saturation at a higher multiplicity of infection . Following the lag phase, during which bacteria invaded poorly, invasion was independent of growth phase . P . gingivalis was capable of replicating within the epithelial cells . Invasion was an active process requiring both bacterial and epithelial cell energy production . Invasion was sensitive to inhibitors of microfilaments and microtubules, demonstrating that epithelial cell cytoskeletal rearrangements are involved in bacterial entry . P . gingivalis, but not epithelial cell, protein synthesis was necessary for invasion . Invasion within the epithelial cells was not blocked by inhibitors of protein kinase activity . Invasion was inhibited by protease inhibitors, suggesting that P . gingivalis proteases may be involved in the invasion process . Low-passage clinical isolates of P . gingivalis invaded with higher efficiency than the type strain . Serum inhibited invasion of the type strain but had no effect on the invasion of a clinical isolate . Invasion of gingival epithelial cells by P . gingivalis may contribute to the pathology of periodontal diseases.

Infect Immun, 1995 Oct, 63(10), 3759 - 64
Relationship between virulence of Mycobacterium avium strains and induction of tumor necrosis factor alpha production in infected mice and in in vitro-cultured mouse macrophages; Sarmento AM et al.; We studied the ability of two Mycobacterium avium strains with different virulences to induce tumor necrosis factor alpha (TNF) synthesis by mouse resident peritoneal macrophages (RPM phi) in vitro in an experiment to look for a possible correlation between virulence and this TNF-inducing capacity . The low-virulence strain, 1983, induced significantly higher production of TNF by RPM phi than did the high-virulence strain, ATCC 25291 . TNF neutralization during culture of infected RPM phi resulted in enhancement of growth of strain 1983 and had no effect on growth of strain ATCC 25291; TNF treatment of strain ATCC 25291-infected macrophages had no effect on mycobacterial growth . The extent of M . avium growth and the amount of TNF synthesis were independent of the presence of contaminating T cells or NK cells in the macrophage monolayers . Intraperitoneal administration of anti-TNF monoclonal antibodies to BALB/c mice infected intravenously with M . avium 1983 abrogated the elimination of the bacteria in the liver and caused a slight increase in bacterial growth in the spleen . Neutralization of TNF led to a minor increase in the proliferation of M . avium ATCC 25291 in the liver and spleen of BALB/c mice late in infection . Anti-TNF treatment did not affect the growth of the two M . avium strains in BALB/c.Bcgr (C.D2) mice, suggesting that restriction of M . avium strains to induce TNF production by macrophages may limit their ability to proliferate both in vitro and in vivo.

Am J Respir Crit Care Med, 1995 Oct, 152(4 Pt 2), S4 - 12
The clinical impact of human respiratory virus infections; Denny FW Jr; Acute respiratory infections are the most frequent illnesses of the human host . Most infections are caused by viruses and bacteria; the proportion caused by viruses is much greater . The viruses most frequently involved are adenoviruses, influenza viruses, parainfluenza viruses, respiratory syncytial viruses, and rhinoviruses . Acute respiratory infections are more common in young children, have rather specific seasonal occurrences, and some agents are associated with specific respiratory syndromes . Risk factors associated with increased incidence or severity of respiratory infections are occurrence in the very young or the elderly; crowding; being male; inhaled pollutants; anatomic, metabolic, genetic or immunologic disorders; and malnutrition, including vitamin or micronutrient deficiency . Respiratory infections are a much greater problem in developing countries than in developed countries and are the leading causes of death in children under 5 yr of age . The same agents cause infections, and the incidence of total respiratory infections is the same as in the developed countries . The precise causes of increased morbidity and mortality in the developing world are unclear, but crowding, inhaled pollutants, and malnutrition are likely candidates . The interactive role of viruses and bacteria is not clear but may play a role in increased severity of respiratory infections.

Pharmazie, 1995 Oct, 50(10), 647 - 62
Strategies and recent technologies in drug discovery; Kubinyi H; In the last years, the paradigms of drug research changed significantly . New technologies were developed, in several different fields . Combinatorial chemistry and high-throughput screening increase our chances to find new lead structures, with less effort than by dedicated syntheses . Gene technology, in addition to providing therapeutically useful proteins, significantly contributes to rational drug design . The primary structure of a protein can be derived from the DNA sequence of the corresponding gene . Its relevance for a certain disease is investigated in transgenic animals . Expression of the protein in bacteria or in cell culture produces material for screening systems and for 3D structure determination by protein crystallography . NMR techniques, or electron cryo-microscopy . Structure-based and computer-aided design methods are applied to optimize lead structures with the least effort . A serious problem in the application of such techniques is their limitation to ligand-protein interactions . For the design of a therapeutically useful drug, also absorption, distribution, metabolism and elimination have to be considered . QSAR methods help in this respect . Scope and limitations of the new technologies are discussed in the context of conventional approaches in drug discovery.

HNO, 1995 Oct, 43(10), 619 - 23
{Necrotizing fasciitis of soft tissues of the face and neck}; Zbaren P et al.; Three cases of cervical necrotizing fasciitis are presented . One case was odontogenic in origin and two were due to pharyngeal infectious . Bacteria cultured represented multiple bacterial species . Airway control was necessary early, as was wide surgical exploration of the fascial spaces of the neck with re-exploration as necessary . Intensive medical support was crucial to prevent or treat complications . Cervical necrotizing fasciitis has an overall mortality rate of 30 per cent at the University of Bern.

Jpn J Cancer Res, 1995 Oct, 86(10), 916 - 23
Gastric cancer among the Japanese in Hawaii; Nomura AM et al.; The incidence rate of gastric cancer among men of Japanese ancestry living in Hawaii is about one-third as high as that of their counterparts living in Japan . Because of this difference, a prospective study was conducted to identify factors related to the development of gastric cancer in Hawaii . Eight thousand and six (8,006) men born from 1900-1919 were examined from 1965 to 1968 and followed for over 25 years . During this time, 250 incident cases of gastric cancer were identified . The study has found the following: 1) prior infection with Helicobacter pylori bacteria increased the risk for stomach cancer; 2) cigarette smoking was positively associated with gastric cancer with age at which smoking started being an important risk factor; 3) after taking cigarette smoking into account, alcohol intake was not related to stomach cancer risk; 4) a low pepsinogen I level identified subjects at increased risk for the intestinal histologic type of gastric cancer; 5) a low serum ferritin level was a marker for increased risk of stomach cancer; 6) there was a weak indication that the intake of vegetables and fruits was inversely related to gastric cancer; 7) there was no association of stomach cancer with levels of serum cholesterol, serum uric acid, serum micronutrients (retinol, beta-carotene or alpha-tocopherol) or blood hematocrit; 8) there was also no association of gastric cancer with body mass index or physical activity.

Bioessays, 1995 Oct, 17(10), 891 - 8
Dual mechanisms of lymphocyte-mediated cytotoxicity serve to control and deliver the immune response; Smyth MJ; Cytotoxic lymphocytes play a central role in immune inflammatory responses against tumour cells, viruses and cells transplanted or infected with intracellular bacteria . The pivotal importance of lymphocytes in each of these immune responses has justified our continued interest in their cytotoxic function . Recent studies of cytotoxic lymphocytes have involved the characterisation of recognition structures on cytotoxic lymphocytes and the definition of two mechanisms of cytotoxicity . In contrast to normal cell death, which occurs during embryonic development and the formation and death of hematopoietic cell lineages, lymphocyte-mediated cytotoxicity occurs in the context of an inflammatory response and the dying cells are lysed into the surroundings rather than phagocytosed . The roles of the two different forms of lymphocyte-mediated cytotoxicity are quite distinct; however they both involve induction of an endogenous pathway of apoptosis in the targeted cell, and they do share features with all other forms of physiological cell death.

Appl Environ Microbiol, 1995 Oct, 61(10), 3695 - 700
Evidence for indigenous Streptomyces populations in a marine environment determined with a 16S rRNA probe; Moran MA et al.; A 16S rRNA genus-specific probe was used to determine whether Streptomyces populations are an indigenous component of marine sediment bacterial communities . Previous debates have suggested that marine Streptomyces isolates are derived not from resident populations but from spores of terrestrial species which have been physically transported to marine ecosystems but remain dormant until isolation . Rigorously controlled hybridization of rRNA extracted from coastal marsh sediments with the genus-specific probe indicated that Streptomyces rRNA accounted for 2 to 5% of the sediment community rRNA and that spores are not the source of the hybridization signal . Streptomyces populations must therefore be at least the 26th most abundant genus-level source of bacterial rRNA . the relative amounts of rRNAs from Streptomyces spp . and members of the Bacteria (69 to 79%) and Archaea (4 to 7%) domains were highly consistent in these marine sediments throughout an annual cycle, indicating that the species composition of sediment bacterial communities may be more stable than recent studies suggest for marine planktonic bacterial communities . Laboratory studies designed to investigate the possible functional roles of Streptomyces populations in coastal sediments demonstrated that population levels of this genus changed relatively rapidly (within a time frame of 6 weeks) in response to manipulation of substrate availability . Amendments of intact sediment cores with two compounds (vanillic acid and succinic acid) consistently resulted in Streptomyces populations contributing an increased percentage of rRNA (6 to 15%) to the total bacterial rRNA pool.

Am J Trop Med Hyg, 1995 Oct, 53(4), 397 - 404
Growth and migration of Borrelia burgdorferi in Ixodes ticks during blood feeding; De Silva AM et al.; We have studied the growth of Borrelia burgdorferi in nymphal ticks (Ixodes scapularis) feeding on mice using confocal fluorescence microscopy to follow the distribution of spirochetes . In starved nymphs, the bacteria were only detected in the midgut and each nymph had a mean of 496 spirochetes . Upon attachment of nymphs to the host, the bacteria grew with a doubling time close to 4 hr and reached a mean of 7,848 spirochetes per nymph 15 hr after attachment . During this initial period (36 hr) of rapid growth, the bacteria appeared to be restricted to the gut, but after 48 hr, the spirochetes had disseminated to the salivary glands in the majority of nymphs examined . Thus, a critical event that allows the spirochetes to disseminate and infect the salivary glands takes place 36-48 hr after attachment . A maximum number of 166,575 spirochetes per nymph was noted 72 hr after attachment . Soon after completion of feeding and detachment from the host (96 hr), the mean number of spirochetes decreased to 95,410 per nymph and the spirochetes appeared to be cleared from organs other than the midgut . Thus, dissemination of spirochetes within the vector appears to be a transient phenomenon . These results provide strong evidence in favor of a salivary route of disease transmission while also demonstrating the utility of confocal microscopy to study vector-pathogen interactions in general.

Philos Trans R Soc Lond B Biol Sci, 1995 Sep 29, 349(1329), 271 - 81
Evolution of the cell cycle; Nasmyth K; Cell proliferation involves duplication of all cell constituents and their more-or-less equal segregation to daughter cells . It seems probable that the performance of primitive cell-like structures would have been dogged by poor duplication and segregation fidelity, and by parasitism . This favoured evolution of the genome and with it the distinction between 'genomic' components like chromosomes whose synthesis is periodic and most other 'functional' components whose synthesis is continuous . Eukaryotic cells evolved from bacterial ancestors whose fused genome was replicated from a single origin and whose means of segregating sister chromatids depended on fixing their identity at replication . Evolution of an endo- or cytoskeleton, initially as means of consuming other bacteria, eventually enabled evolution of the mitotic spindle and a new means of segregating sister chromatids whose replication could be initiated from multiple origins . In this primitive eukaryotic cell, S and M phases might have been triggered by activation of a single cyclin-dependent kinase whose destruction along with that of other proteins would have triggered anaphase . Mitotic non-disjunction would have greatly facilitated genomic expansion, now possible due to multiple origins, and thereby accelerated the tempo of evolution when permitted by environmental conditions.

Philos Trans R Soc Lond B Biol Sci, 1995 Sep 29, 349(1329), 263 - 9
The sodium pump in the evolution of animal cells; Stein WD; Plant cells and bacterial cells are surrounded by a massive cellulose wall, which constrains their high internal osmotic pressure (tens of atmospheres) . Animal cells, in contrast, are in osmotic equilibrium with their environment, have no restraining surround, can take on a variety of shapes and change these from moment to moment . This osmotic balance is achieved by the action of the energy-consuming sodium pump, one of the P-type ATPase transport protein family, members of which are indeed also found in bacteria . The pump's action brings about a transmembranal electrochemical gradient of sodium ions, harnessed in a range of transport systems that couple the dissipation of this gradient to establishing a gradient of the coupled substrate . The primary role of the sodium pump as a regulator of cell volume has evolved to provide the basis for an enormous variety of physiological functions.

J Immunol Methods, 1995 Sep 25, 185(2), 245 - 8
Quick purification of recombinant human truncated tau proteins for immunoanalysis; Kontsekova E et al.; A simple and rapid purification method is described which exploits the heat stability of human tau (tau) protein to prepare truncated forms of this protein derived from bacteria . Bacterial cells expressing tau fragments were pelleted, resuspended in phosphate buffered saline and boiled for 5 min . After centrifugation the supernatant containing thermostable tau was filtered (0.45 microns) and used for immunoanalysis with monoclonal antibodies . The purified tau fragments exhibited identical antigenic properties as fragments isolated by a conventional procedure, based on ion exchange chromatography on phosphocellulose . In contrast to the conventional approach, our method is less complicated, cheaper and significantly reduces the time required for isolation of the recombinant tau fragments.

Neurosci Lett, 1995 Sep 22, 198(1), 52 - 6
Amino-terminal region of the beta-amyloid precursor protein activates mitogen-activated protein kinase; Greenberg SM et al.; The secreted form of the beta-amyloid precursor protein (beta-APP) has previously been shown to stimulate mitogen-activated protein (MAP) kinases in PC-12 pheochromocytoma cells . The amino-terminal half of secreted beta-APP contains a region rich in cysteine residues reminiscent of cysteine-rich binding regions in other families of extracellular proteins . We found that reductive alkylation of disulfide linkages eliminated the ability of secreted beta-APP to activate MAP kinase . To confirm the role of the cysteine-rich amino-terminal region, fragments representing the amino- and carboxyl-terminal halves of secreted beta-APP were expressed in bacteria as fusion proteins and purified . Ten-minute treatment with the amino-terminal segment of beta-APP activated MAP kinase approximately 15-fold, while the carboxyl segment had no effect . The amino-terminal fragment, like intact secreted beta-APP, was substantially inactivated by reduction of sulfhydryl groups . These results suggest that the amino-terminal region of beta-APP is responsible for activation of MAP kinase and that it requires structural loops created by disulfide linkages for activity.

J Biol Chem, 1995 Sep 22, 270(38), 22478 - 82
The DpsA protein of Synechococcus sp . Strain PCC7942 is a DNA-binding hemoprotein . Linkage of the Dps and bacterioferritin protein families; Pena MM et al.; The Dps family of proteins are a diverse group of bacterial stress-inducible polypeptides that bind DNA and likely confer resistance to peroxide damage during periods of oxidative stress and long term nutrient limitation . Some members of the Dps protein family have been shown to form large (approximately 150-kDa), hexameric complexes that bind chromosomal DNA with little sequence specificity . In this paper we report the nucleotide sequence of the dpsA gene from Synechococcus sp . PCC7942 encoding a cyanobacterial Dps homolog . The deduced amino acid sequence of the Synechococcus sp . DpsA protein revealed that a carboxyl-terminal domain of the protein was > 60% homologous to the COOH-terminal half of bacterioferritin . Other known Dps family members lack such high similarity to the bacterioferritins . Purification and spectroscopic analysis of the Synechococcus sp . DpsA protein complex revealed that the complex contains heme and has a weak catalase activity in vitro . Activity staining of nondenaturing polyacrylamide gels showed that the protein complex comigrated with both the heme and the catalase activity, and O2 evolution measurements yielded a maximal specific activity of 1.7 mumol of H2O2 consumed/micrograms of protein-1 min-1 . We speculate that the protein may have a peroxide-consuming mechanism located on the chromosomal DNA, and we also suggest that this activity may be a necessary feature to handle the endogenous oxidative stresses associated with oxygenic photosynthesis . Last, the evolutionary link between the Dps protein family and the bacterioferritins is discussed.

Biochim Biophys Acta, 1995 Sep 19, 1263(3), 235 - 40
Triple helix directed psoralen adducts induce a low frequency of recombination in an SV40 shuttle vector; Sandor Z et al.; Triple helix forming oligonucleotide directed psoralen adducts in a mammalian shuttle vector have been reported to be repaired efficiently in human cells . In this study we examined the role of intermolecular homologous recombination in triple helix targeted psoralen adduct repair . A simian virus 40 (SV40) shuttle vector carrying a mutated supF gene was treated with a triplex forming oligonucleotide psoralen conjugate and cotransfected into human cells with a second plasmid bearing the wild type supF gene . Recombinants with a reactivated marker gene were detected by an X-gal assay in indicator bacteria . We could observe a low frequency of psoralen adduct induced recombination indicating that recombination does not play a major role in triplex directed psoralen adduct repair . The implications for targeted mutagenesis by triple helix forming oligonucleotides are discussed.

Biochemistry, 1995 Sep 19, 34(37), 11831 - 9
Membrane-bound c-type cytochromes in Heliobacillus mobilis . In vivo study of the hemes involved in electron donation to the photosynthetic reaction center; Nitschke W et al.; The amount of heme per photosynthetic reaction center (RC) was examined in whole cells of Heliobacillus mobilis, and a stoichiometry of 5-6 hemes c and 1-3 hemes b per RC was found . Virtually the full complement of heme was seen to be functionally connected to the pool of electron donors to the photosynthetic RC . The kinetic parameters of electron transfer between reduced c-type hemes and the photooxidized primary donor P798+ were studied in whole cells and membrane fragments . The in vivo half-times of electron donation (50% with t 1/2 = 110 microseconds, 50% with t 1/2 = 600 microseconds) were seen to slow down to half-times in the range of several and several tens of milliseconds following disruption of cells . A severe conformational alteration or a change in the identity of the donating heme is discussed . Redox titrations of the flash-induced absorption changes performed on whole cells in the presence of mediators yielded the following redox midpoint potentials: P798, Em = +240 mV; heme c553, Em = +190, +170, and +90 mV for the heme components oxidized after the first, second, and third flash, respectively . The results demonstrate that the pool of c553 hemes donating electrons to the RC is heterogeneous and that it consists of either several distinguishable cytochromes or multiheme cytochromes or both . The number of hemes reduced and the kinetics of heme rereduction after flash-induced oxidation were found to depend strongly on the degree of anaerobicity in the interior compartment of the cell . A model rationalizing the obtained results in terms of a set of differing redox components is proposed.

Eur J Biochem, 1995 Sep 15, 232(3), 811 - 7
Reversible super-reduction of the cubane {4Fe-4S}(3+;2+;1+) in the high-potential iron-sulfur protein under non-denaturing conditions . EPR spectroscopic and electrochemical studies; Heering HA et al.; The reversible 2 x 1 e- reduction of the cubane cluster from oxidized to reduced to super-reduced states ({4Fe-4S}3+<-->{4Fe-4S}2+<-->{4Fe-4S}1+) was studied in high-potential iron-sulfur proteins (HiPIPs) . Super-reduction to the 1+ state was not observed in any of the seven HiPIPs tested during cyclic voltammetry (down to -0.95 V) . However, equilibration at low potential (pH 7.5) of Rhodopila globiformis HiPIP yields a transient peak around -0.47 V due to the oxidation of super-reduced HiPIP adsorbed at the electrode . The peak area depends on the equilibration potential according to a one-electron Nernst curve with a half-wave potential at -0.91 V . Reduction of R . globiformis HiPIP with titanium (III)citrate at pH 9.5 is very slow {pseudo-first-order half-life of 23 min with a 100-fold excess Ti(III)} but is reversible, and the EPR spectrum with g values of 2.04 and 1.92 is similar to that of reduced {4Fe-4S}1+ ferredoxins . Chemical or electrochemical reoxidation of the super-reduced form resulted in an EPR spectrum with g parallel = 2.12 and g perpendicular = 2.03, i.e . identical to that of oxidized HiPIP . From the equilibrium concentration of super-reduced HiPIP at a low concentration of Ti(III), a reduction potential of -0.64 V can be estimated . Super-reduction of the large HiPIP (iso-2) from Rhodospirillum salinarum is also possible with Ti(III)(gz = 2.05) but the super-reduced state is unstable . No super-reduction with Ti(III) was observed for the other HiPIPs . The difference between the electrochemically observed reduction potential and oxidation potential is explained by a fast and reversible conformational change upon super-reduction . The rate of super-reduction with Ti(III) is limited by the small amount (0.1%) of HiPIP in the 2+ state with the super-reduced conformation.

Carbohydr Res, 1995 Sep 15, 275(1), 147 - 54
Structure of the capsular polysaccharide from Alteromonas sp . CMM 155; Zubkov VA et al.; Capsular polysaccharide (CPS) was obtained by water-saline extraction of the Alteromonas sp . CMM 155 . On the basis of solvolysis with anhydrous HF and 1H- and 13C-NMR spectral data, including NOE experiments, it was concluded that the capsular polysaccharide had the following structure containing novel N-acyl-amino sugar and bacillosamine residues: --> 3)-alpha-D-GalpNAc-(1 --> 4)-alpha-L-GalApNAc(1 --> 3)- alpha-D-QuipNAc4NAc-(1 --> 3)-beta-D-Quip4NAlaAc-(1 -->

Biochem Biophys Res Commun, 1995 Sep 14, 214(2), 568 - 75
Synthesis of three hetero disaccharides, 4-O-beta-glucopyranosyl-6-deoxy-D-glucose, 4-O-beta-D-glucopyranosyl-D-mannosamine, and 4-O-beta-D-glucopyranosyl-D-mannose, and confirmation of their structures by C-13 NMR and MS; Tariq MA et al.; The three disaccharides, 4-O-beta-D-glucopyranosyl-6-deoxy-D-glucose (Glc-6-deoxy-Glc), 4-O-beta-D-glucopyranosyl-D-mannosamine (Glc-ManN), 4-O-beta-D-glucopyranosyl-D-mannose (Glc-Man), were synthesized from equimolar amounts of 6-deoxy-glucose and alpha-D-glucose-1-phosphate (G-1-P), D-mannosamine and alpha-D-glucose-1-phosphate (G-1-P), and D-mannose and alpha-D-glucose-1-phosphate (G-1-P), respectively, using cellobiose phosphorylase from Cellvibrio gilvus . The yields were 60%, 10% and 50% based on the initial amounts of 6-deoxy-D-glucose, D-mannosamine and D-mannose, respectively . The structures of disaccharides were confirmed by NMR and mass spectroscopy analysis.

Biochemistry, 1995 Sep 5, 34(35), 11099 - 105
Symmetric structural features and binding site of the primary electron donor in the reaction center of Chlorobium; Feiler U et al.; The protein binding interactions of the constituent bacteriochlorophyll a molecules of the primary electron donor, P840, in isolated reaction centers from Chlorobium limicola f thiosulphatophilum and the electronic symmetry of the radical cation P840+ . were determined using near-infrared Fourier transform (FT) Raman spectroscopy excited at 1064 nm . The FT Raman vibrational spectrum of P840 indicates that it is constituted of a single population of BChl a molecules which are spectrally indistinguishable . The BChl a molecules of P840 are pentacoordinated with only one axial ligand on the central Mg atom, and the pi-conjugated C2 acetyl and C9 keto carbonyls are free of hydrogen-bonding interactions . The FT Raman spectrum of P840+ . exhibits a 1707 cm-1 band attributable to a BChl a C9 keto carbonyl group vibrational frequency that has upshifted 16 cm-1 upon oxidation of P840; this upshift is exactly one-half of that expected for the one-electron oxidation of monomeric BChl a in vitro . The 16 cm-1 upshift, thus, indicates that the resulting +1 charge is equally shared between two BChl a molecules . This situation is markedly different from that of the oxidized primary donor of the purple bacterial reaction center of Rhodobacter sphaeroides, (i) which exhibits a 1717 cm-1 band that has upshifted 26 cm-1, indicating an asymmetric distribution of the resulting +1 charge over the two constituent BChl a molecules, and (ii) whose H-bonding pattern with respect to the pi-conjugated carbonyl groups is asymmetric.(ABSTRACT TRUNCATED AT 250 WORDS)

Lik Sprava, 1995 Sep-Dec, (9-12), 67 - 9
{The results of a clinical trial of flurenizid in phthisiopulmonology practice}; Il'nyts'kyi IH et al.; Flurenizide, a new home drug preparation, endowed with antituberculosis activity, was administered to 20 patients with freshly detected pulmonary tuberculosis, in combination with etambutole or rifampycin in a daily dose of 0.6 g . After the above chemotherapy, closure of the cavities, diminution in size and consolidation of the foci as well as infiltrates, dispelling of the symptoms of intoxication, and discontinuance of bacteria discharge were observable in 70.0 percent of the cases . The drug is well tolerated by patients and is not associated with side effects . The results obtained permit recommending flurenizide for use in phthisiopulmonological practice.

Gastroenterol Clin North Am, 1995 Sep, 24(3), 633 - 46
Extraintestinal considerations in inflammatory bowel disease; Levine JB et al.; If one reviews the literature with zeal, it is increasingly apparent that few organs escape recruitment when IBD is chronic or progressive . Insights into mucosal pathophysiology have helped with understanding the more frequent extraintestinal manifestations, but the mechanisms attendant to the development of less common events (e.g . acute pancreatitis, concurrent gluten sensitive enteropathy, or active pulmonary disease) remain either poorly studied or obscure . It is particularly interesting, however, to read reports of abnormal pulmonary function, generally of the obstructive type, correlated to measurements of abnormal intestinal permeability in patients with either active pulmonary sarcoid or pulmonary involvement in Crohn's disease . It has been further speculated that similarities in the mucosal immune system of the lung and intestine are responsible for evidence of bronchial hyperreactivity in patients with active IBD . Finally, it is important to recognize that extensions of the inflammatory process are not restricted to the development of organ-based events but may be responsible for some of the most frequent systemic abnormalities detected in IBD patients . It is now also well confirmed that the cytokine environment in IBD can support activated coagulation and, in some clinical situations, overt vascular thrombosis . The cerebrovascular complications of IBD are well recognized and range from peripheral venous thrombosis to central stroke syndromes and pseudotumor cerebri . Reports of focal white matter lesions in the brains of patients with IBD or an increased incidence of polyneuropathy may be other clinical examples of regional microvascular clotting . Microvascular injury appears to be more ubiquitously present, with reports ranging from a speculated primary causative role (e.g., granulomatous vasculitis in the mesenteric circulation) to the utility of nailbed vasospasm, in Crohn's disease, as a clinical marker for disease activity . It is also reported that IL-6 suppression of erythropoietin production is a major feature of the chronic anemia seen in active IBD . Moreover, the capacity of peripheral monocytes from active IBD patients to secrete TNF and IL-8 is reported predictive for the degree of therapeutic response from recombinant erythropoietin . These collected observations constitute another excellent example of the symmetry between basic science and clinical utility . It is from the context of applied basic science that many future therapies will arise . Empiricism will lose much of its appeal as clinical observations will be increasingly translated into cellular language . Already in animal models, elemental diets diminish IL-6-related acute inflammatory injury, and reductions in dietary lipid alter the antigenicity of bacteria . Provocatively, in humans, unconfirmed reports have even associated diet therapy with the resolution of uveitis and pyoderma gangrenosum . It is likely that efforts will also be made to induce oral tolerance if specific triggering proteins are discovered or to alter bowel flora if such an arcane area of investigation becomes resurgent.

Gastroenterol Clin North Am, 1995 Sep, 24(3), 475 - 507
Current concepts of the etiology and pathogenesis of ulcerative colitis and Crohn's disease; Sartor RB; Although the causes, events initiating and triggering inflammation, and the precise immunoregulatory defects of IBD are still not known, investigations have provided a better understanding of the mechanisms of perpetuation of inflammation, genetic susceptibility, tissue injury, and symptoms . Ulcerative colitis and Crohn's disease are related disorders that probably share susceptibility genes and have similar nonspecific inflammatory mediator profiles . These diseases, however, almost certainly have different causes and respond to different antigenic stimuli . It is probable that both ulcerative colitis and Crohn's disease represent heterogenic groups of diseases that share similar mechanisms of tissue damage but have different initiating events and immunoregulatory abnormalities . Rodent models demonstrate that a wide variety of initial injuries or perturbations of immunoregulatory pathways can lead to similar phenotypes of intestinal injury, and human studies show evidence of genetic heterogeneity . It is equally apparent from these models that initiating and perpetuating mechanisms are entirely distinct and that the intestine has a remarkable ability to heal . Chronicity of disease depends on continued exposure to toxic luminal components, most commonly of bacterial origin, and genetically determined host susceptibility . Precise mechanisms of differential genetic susceptibility remain unclear, but defective down-regulation of inflammation is consistent with clinical and experimental observations . The author proposes the following sequence of events (Fig . 9) . Nonspecific intestinal inflammation can be induced by a wide variety of enteric infections or ingested toxins . Resultant increased mucosal permeability leads to enhanced uptake of toxic luminal bacterial products, which potentiate local injury . The vast majority of hosts respond to these injurious events by promptly down-regulating the inflammatory response and rapidly healing the mucosal damage without residual scarring . The genetically susceptible host, however, who lacks the ability to suppress the inflammatory response efficiently, has inappropriate amplification of the immune cascade . In response to constant exposure to phlogistic luminal constituents, these patients develop an unrestrained inflammatory response, leading to tissue destruction, chronic inflammation, and fibrosis . Thus, IBD is caused by a genetically determined defective down-regulation of inflammation driven by ubiquitous antigens . Luminal anaerobic bacterial antigens are the stimuli in Crohn's disease, but ulcerative colitis may be caused by functionally abnormal aerobic bacteria or primary defects in epithelial cell physiology . Spontaneous or therapy-induced remissions can be achieved, but the risk of reactivation of inflammation is high because of the frequent exposure to triggering episodes that can reignite the inflammatory cascade . {formula: see text} This theory suggests that the intestine is in a constant state of controlled inflammation, mediated by a balance between aggressive luminal forces and host protective mechanisms (Fig . 10) . This delicate balance can be deranged by any number of environmental triggering events and is in dysequilibrium in IBD . Amplification of the inflammatory response activates effector cells and cascades of soluble inflammatory molecules, which mediate tissue injury and physiologic responses leading to symptoms of IBD . These relatively nonspecific events are the target of most current therapeutic agents, which can inhibit but not completely block intestinal inflammation because of the overwhelming number of parallel pathways involved . Specific inhibition of selected effector molecules is intellectually intriguing but is less likely to paralyze the inflammatory response during clinically apparent inflammation than is blockade of key immunoregulatory cells and molecules . Better understanding of initiating, perpetuating, and immunoregulatory mechanisms should provide more

Anal Chem, 1995 Sep 1, 67(17), 3051 - 6
Thin-layer immunoaffinity chromatography with bar code quantitation of C-reactive protein; Nilsson S et al.; A rapid thin-layer immunoaffinity chromatographic method for quantitation in serum of an acute phase reactant, C-reactive protein (CRP), which can differentiate between viral and bacteria} infections, is described, where material and reagent costs are minimal . The analysis is based on the inverted question marksandwich inverted question mark assay format using monoclonal antibodies directed against two sites of CRP . One of the antibodies is covalently bound to defined zones on a thin-layer immunoaffinity chromatography membrane, while the other antibody is covalently bound to deeply dyed blue latex particles . After incubation (CRP sample and latex particles), the CRP-latex immunocomplex is allowed to migrate along the immunoaffinity chromatography membrane . In the presence of antigen, a sandwich is formed between the CRP-latex immunocomplex and membrane-bound antibodies, which results in the appearance of blue lines on the membrane . Antibody immobilization on the TLC membrane is made with a redesigned piezoelectric-driven ink-jet printer . The time required for the analysis is less than 10 min . Quantitation is achieved either by counting the lines visually, with scanning reflectometry, or with a modified bar code reader . The limit of detection was estimated in the low femtomolar range using the naked eye as detector.

Rev Assoc Med Bras, 1995 Sep-Oct, 41(5), 325 - 8
{Influence of bile salts on the motor response of isolated ileum to acetylcholine, in rats}; Duval-Araujo I et al.; Absence of bile salts in the intestinal lumen of jaundiced patients is associated to bacterial overgrowth and systemic endotoxemia . These bile salts, however, did not show significant influence on aerobic and facultative intestinal bacteria . The increasing bacterial colonization may be due to depressed intestinal motor response . PURPOSE: To evaluate the influence of bile salts on intestinal motor response in presence of obstructive jaundice . METHODS: We studied in vitro the motor response of ileal segments of 30 Holtzman rats divided into three groups (n = 10): washed ileum, intraluminal bile salts and exogenous oral bile salts administred during six days . Five animals of each group were submitted to sham operation and the other five were submitted to ligation and section of the common bile duct . A four centimeter ileal segment was isolated and studied through a dose-response assay with acetylcholine in an organ chamber . RESULTS: The results showed an increased ileal affinity to acetylcholine in presence of intraluminal bile salts . CONCLUSION: The intraluminal bile salts appear to exert in vitro a stimulatory effect on ileal motility.

Zhonghua Kou Qiang Yi Xue Za Zhi, 1995 Sep, 30(5), 274 - 6, 319-20
{Preventive effect of 10% (NH4)2MoO2F4 solution on artificial root-surface caries in vitro}; Yang D et al.; The aim of this study is to determine the preventive effect of F-Mo preparation on artificial root-surface caries . 60 premolar teeth extraced for orthodontic purpose were divided into five groups . A window was prepared on every tooth . They were treated by 10% (NH4)2MoO2F4, 38%Ag (NH4)2F, 2% NaF, 7.3% (NH4)2MoO4 and deionized water for 2 minutes and three times . They were then put in the fluid contained cariogenic bacteria for 96 hours to produce root caries . The root surface lesion of every tooth was examined and analysed by micro-radiography, SEM and spectrum . The result showed that the lesion depth of the groups treated by 10% (NH4)2MoO2F4 and 38%Ag (NH4)2F were significantly smaller than the other groups, and the surface of windows are more integrate and smooth, and mean mineral concentration is more higher than those of the other groups . It can be concluded that 10% (NH4)2MoO2F4 solution has greater inhibit effect to the development of root caries, so as the 38% Ag(NH4)2F solution . But the former discolored the tooth much less than the latter.

Oper Dent, 1995 Sep-Oct, 20(5), 197 - 203
Microleakage of gold casting repairs with different materials as quantified by a helium gas system; Briseno Marroquin B et al.; Inadequate adaptation of a filling material to a gold crown can promote the passage of bacteria; thus, recontamination of sound dentin and/or the pulp canal space is feasible . The aim of this study was to determine the marginal microleakage between two different amalgams (Tytin and Valiant PHD-XT), three different composites (Tetric, Charisma, and Polofil Molar), and one glass-ionomer cement (Ketac Silver) and gold cast crowns using a helium gas microleakage method . In order to standardize the research parameters, gold washers with standardized dimensions were used as study models together with a helium leakage testing device . Standardized cavities were filled according to the manufacturers' recommendations with the different materials . The amount of helium passing the marginal interface between the fillings and cavities was measured with a mass spectrometer 48 hours after the fillings were placed and 100, 1000, and 2000 thermocycles (5 degrees C-55 degrees C) . The results showed that amalgam allowed the least microleakage . Ketac Silver showed the greatest microleakage . Statistically significant differences were found between the composites and both amalgams and Ketac Silver between the 48-hour and 100-thermocycling groups . Yet, Ketac Silver showed a significant ascending tendency when compared to the composites and amalgams after 100, 1000, and 2000 thermocycles.

Eksp Klin Farmakol, 1995 Sep-Oct, 58(5), 65 - 7
{The efficacy of using synthetic carbon-mineral sorbents in combined radiation-thermal lesions}; Nesterenko VS et al.; The effect of enterosorbents of group "SUMS" on the manifestations of endogenous intoxication syndrome and dysfunction of small intestine was studied in rats with combined radiational-thermal injuries . The "SUMS" enterosorbents are shown to reduce the general toxemia, and promote the recovery of intestinal wall digestion enzyme activity and glucose absorption.

Mol Microbiol, 1995 Sep, 17(5), 901 - 12
Green fluorescent protein as a marker for gene expression and cell biology of mycobacterial interactions with macrophages; Dhandayuthapani S et al.; The green fluorescent protein (GFP) of the jellyfish Aequorea victoria offers certain advantages over other bioluminescence systems because no exogenously added substrate or co-factors are necessary, and fluorescence can be elicited by irradiation with blue light without exposing the cells producing GFP to invasive treatments . A mycobacterial shuttle-plasmid vector carrying gfp cDNA was constructed and used to generate transcriptional fusions with promoters of interest and to examine their expression in Mycobacterium smegmatis and Mycobacterium bovis BCG grown in macrophages or on laboratory media . The promoters studied were: (i) ahpC from Mycoosis and Mycobacterium leprae, a gene encoding alkyl hydroperoxide reductase which, along with the divergently transcribed regulator oxyR, are homologues of corresponding stress-response systems in enteric bacteria and play a role in isoniazid sensitivity; (ii) mtrA, an M . tuberculosis response regulator belonging to the superfamily of bacterial two-component signal-transduction systems; (iii) hsp60, a previously characterized heat-shock gene from M . bovis; and (iv) tbprc3, a newly isolated promoter from M . tuberculosis . Expression of these promoters in mycobacteria was analysed using epifluorescence microscopy, laser scanning confocal microscopy, fluorescence spectroscopy, and flow cytometry . These approaches permitted assessment of fluorescence prior to and after macrophage infection, and analyses of promoter expression in individual mycobacteria and its distribution within populations of bacterial cells . Bacteria expressing GFP from a strong promoter could be separated by fluorescence-activated cell sorting from cells harbouring the vector used to construct the fusion . In addition, the stable expression of mtrA-gfp fusion in M . bovis BCG facilitated localization and isolation of phagocytic vesicles containing mycobacteria . The experiments presented here suggest that GFP will be a useful tool for analysis of mycobacterial gene expression and a convenient cell biology marker to study mycobacterial interactions with macrophages.

Transgenic Res, 1995 Sep, 4(5), 332 - 40
Effect of the dpy-20 and rol-6 cotransformation markers on alpha-tubulin gene expression in C . elegans transformants; Fukushige T et al.; An alpha-1 tubulin::lacZ fusion gene was introduced into the germline of Caenorhabditis elegans, using either rol-6 or dpy-20 genomic DNA as a cotransformation marker . Distinct patterns in cellular specificity of the alpha-1 tubulin::lacZ fusion gene expression were observed, depending on the cotransformation marker used . For the rol-6 marker, the tubulin fusion gene was expressed in several neurons in the head and tail ganglia and a set of 38-39 ventral cord motor neurons along the body length of the animal during larval and adult development . In contrast, for the dpy-20 marker system, not only were fewer neurons stained in the head and tail region, but also the staining of ventral cord motor neurons was extremely reduced both in number and intensity . The dpy-20 marked-mediated suppression of the alpha-1 tubulin gene expression was observed both in the cis and trans configurations . Similar down-regulation in the ventral cord motor neurons was observed when the alpha-2 tubulin::lacZ fusion gene construct was tested in these experiments using the dpy-20 marker . In controls, where the tubulin fusion gene was directly injected to obtain transformants without any marker DNA, the cellular staining pattern was close to the fusion gene expression observed with the rol-6 marker DNA . These results underline the importance of the choice of transformation marker system in generation of the transgenic animals, and reveal a down-regulation of the alpha-tubulin fusion gene expression in the ventral cord motor neurons in transgenic animals when the dpy-20 gene was used as a cotransformation marker.

Physiol Behav, 1995 Sep, 58(3), 471 - 6
Behaviorally conditioned anorexia: role of gastric emptying and prostaglandins; Exton MS et al.; The reduction of food intake in response to bacteria is posited to be a favourable host reaction . This report attempted to examine whether gastric emptying is involved in the known conditionability of this response . Additionally, this study investigated the role of prostaglandins in the conditioned anorexic response . To investigate this phenomenon, lipopolysaccharide (LPS) (100 micrograms/kg) was used as the unconditioned stimulus, and paired with a novel 1% saccharin solution (conditioned stimulus) . Upon conditioned stimulus (CS) representation, experimental animals displayed a marked reduction in food consumption (experiment 1) and emptying of gastric contents (experiment 2) . Additionally, treatment with indomethacin upon CS reexposition blocked both the conditioned anorexia and suppression of gastric emptying . These results indicate that conditioned anorexia is possibly the result of a conditioned inhibition of gastric emptying, and this process is mediated by conditioned alterations in PG levels.

J Neurobiol, 1995 Sep, 28(1), 82 - 101
Hu protein as an early marker of neuronal phenotypic differentiation by subependymal zone cells of the adult songbird forebrain; Barami K et al.; The avian forebrain exhibits neurogenesis in adulthood, with neuronal production from ependymal/subependymal zone (SZ) precursor cells . To follow the commitment of newborn cells to neuronal lineage, we used their expression of the Hu family of neuronal RNA-binding proteins to identify them before their migration from the SZ . Adult canaries were injected with {3H}thymidine as a marker of DNA replication, sacrificed after varying intervals, stained for Hu, and autoradiographed . We found that Hu was not expressed by premitotic precursor cells, but rather appeared within hours in their neuronal progeny, which did not embark on parenchymal migration until 4 to 7 days later . Hu was expressed by all neurons, but not glia, both in vivo and in vitro, as determined by ultrastructural analysis as well as co-localization of Hu and cell-type selective antigens . In addition, co-staining for Hu and N-cadherin, whose expression is down-regulated on neuronal emigration from the SZ, revealed their initial co-expression by neuronal daughter cells still within the SZ . These results suggest that Hu expression may be used as a very early indicator of neuronal differentiation by SZ cells . Furthermore, the data indicate that in the adult avian brain, neuronal phenotype is established within hours of precursor mitosis, even though the neuronal daughter cells do not initiate parenchymal migration for at least 4 days thereafter, following their down-regulation of N-cadherin.

Int J Immunopharmacol, 1995 Sep, 17(9), 787 - 92
In vivo study of the immunomodulating activity of OM-85 using the plaque-forming cells technique (PFC) in mice; Mimouni J et al.; The activity of increasing oral doses of the bacterial extract OM-85 was determined by using the plaque-forming cells assay in mice . The results showed that the oral administration of OM-85 significantly increased the number of splenic antibody-secreting cells against sheep red blood cells (antigen) compared with controls . A maximal response was reached between 400 and 800 mg/kg body weight, and was reproducible with the different batches of OM-85 used . This study indicates that the oral administration of the immunomodulator allows the activation of splenic B-lymphocytes, probably through the gut-associated lymphoid tissue.

Rev Hosp Clin Fac Med Sao Paulo, 1995 Sep-Oct, 50(5), 280 - 3
{Serotypes of pneumococci isolated from children with pneumonia: implication of pneumococcal specific immunization}; Hein N et al.; For the 15 years from 1978 to 1992 serologic typing was performed on 124 pneumococcus isolates from children with acute pneumonia . The source of bacteria was material obtained by aspirative pulmonary punction, pleural fluid or blood; 122 capsular antigens representing groups and types could be determined . Of the 122 isolates serogrouped 14, 1, 6, 5, 4, 7, 23, 19 and 4, accounted for 25.4%; 23.8%; 13.1%; 9.0%; 4.9%; 4.9%; 4.1%; 4.1%; 4.1%; respectively, of cases . The currently available 23-valent vaccine would provide protection against 89.3% of identified pneumococci in our study, but because of its poor immunogenicity in children less than 2 years old (73.0%) they would have received reduced protection by the use of this vaccine . The distribution of pneumococci serogroups found in our study has an intermediary pattern in relation to those found at develop countries (6, 14, 18, 19, 23) and developing ones (1, 2, 3, 5, 7, 12, 46) . The new conjugate vaccines, with limited number of pneumococcal groups/types, should be analysed before the introduction in different geographic areas.

Res Microbiol, 1995 Sep, 146(7), 561 - 8
Variations in DNA concentrations significantly affect the reproducibility of RAPD fingerprint patterns; Davin-Regli A et al.; The influence of the DNA concentration was tested using two different primers and nine DNA samples . Major modifications in the DNA banding pattern were apparent between successive dilutions . Such differences could be explained by concomitant changes in three different molecular conditions: the presence of perfect priming sites, the amplification of rare sites and the existence of mismatch annealing events . At low DNA concentrations (less than 1 pg/microliter), molecular events occurred at random and had a direct consequence on the reproducibility of RAPD profiles . At the appropriate DNA concentration (between 100 ng/microliters and 10 pg/microliters), reproducibility was adequate at a given concentration, but RAPD profiles differed from one dilution to another . These observations demonstrate the usefulness of the bis-benzimide method for quantification of DNA extracts.

Med Hypotheses, 1995 Sep, 45(3), 304 - 10
A co-evolutionary theory of sleep; Korth C; Based on recent experimental evidence, a novel theory of sleep function and regulation is advanced, stating that sleep primarily evolved to protect the brain against a wakefulness-dependent increase in the permeability of the blood-brain barrier . A restitutional mechanism for the blood-brain barrier had to co-evolve against the omnipresent gut-derived bacterial cell wall constituents, because these and their elicited cellular responses increase blood-brain barrier permeability and potentially harm nervous tissue . Thus, in order to develop a highly organized cerebral structure, an immune-like response specific for the brain co-evolved during the phylogeny of the symbiosis between animals and gut bacteria to control the detrimental effects of bacterial cell wall constituents . In the course of further evolution, the sleep-associated 'controlled inflammatory state' of the brain employed the growth-factor activities of locally activated cytokines to enforce cerebral development and the maintenance of cognitive functions.

Glycobiology, 1995 Sep, 5(6), 625 - 31
A sialidase activity in the midgut of the insect Triatoma infestans is responsible for the low levels of sialic acid in Trypanosoma cruzi growing in the insect vector; Amino R et al.; Trypanosoma cruzi expresses a unique trans-sialidase that is responsible for the transfer of sialic acid from host glycoproteins and glycolipids to mucin-like glycoprotein acceptors on the parasite surface . The enzyme and the sialic acid acceptors are present in the mammalian forms of the parasite and in the parasite forms that grow in axenic cultures, which correspond to the developmental stages found in the insect vectors . Here we show that parasite forms growing in the vector Triatoma infestans express trans-sialidase in the hindgut portions of the insect . However, the sialic acid acceptors are poorly sialylated due to the low concentration of sialic acid donors in the gut lumen of T.infestans, which feeds exclusively on blood that is rich in sialic acid donors . These low levels of sialic acid donors are due to a novel sialidase activity present mainly in the anterior midgut with high specificity for alpha-2,3-sialyllactose, but not for alpha-2,6-sialyllactose . The activity is present in starved insects or insects fed with culture medium, indicating that it did not originate from the blood meal . Enzyme activity does not decrease in insects fed with antibiotics, is present in the salivary glands, and the few bacteria isolated from the gut and faeces of T.infestans did not display sialidase activity, indicating that the enzyme is not derived from a commensal organism . This novel activity could have a nutritional role in the gut of haematophagous insects and indicates that acquisition of sialic acid is not required for parasite development in the gut of T.infestans.

Baillieres Clin Gastroenterol, 1995 Sep, 9(3), 487 - 506
Pathogenic mechanisms; Calam J; Research is asking how H . pylori causes diseases, and also why the same bacteria produces different conditions in different persons . The process involves bacterial factors and the host's response . Some bacterial factors such as urease are produced by all strains of H . pylori . This enzyme may damage the gastric epithelium by practically releasing ammonia . Other bacterial factors such as vacuolating toxin are only produced by some strains, and these strains are more likely to cause ulcers or cancer . The host's response has been studied by physiologists, immunologists, and histologists, but the separation of systems is artificial . For example, physiologists find that H . pylori stops gastric D-cells from expressing somatostatin normally, which impairs reflex inhibition of acid secretion, but the D-cell malfunction is probably due to inflammatory factors . In H . pylori gastritis, the gastric epithelial cells behave like immunocytes and express class II molecules and cytokines such as interleukin-8 . The patient's histological response to H . pylori is quite closely related to the disease outcome . Patients who respond by developing gastric atrophy are more likely to get gastric ulcers or stomach cancer, but patients whose gastric corpus remains healthy tend to secrete more acid and develop duodenal ulcers, particularly if they have gastric metaplasia in their duodenum . Studies of disease mechanisms provide a valuable insight into the development of these common diseases, and may enable us to identify at-risk groups who particularly merit eradication therapy.

Exp Physiol, 1995 Sep, 80(5), 735 - 43
Selective transport of microparticles across Peyer's patch follicle-associated M cells from mice and rats; Smith MW et al.; M cells are specialized structures in the Peyer's patch follicle-associated epithelium capable of taking up bacteria, viruses and other pathogens for later presentation to the gut-associated lymphoid tissue . The present work studies how coating microspheres with different proteins affects their ability to be taken up by M cells under near physiological conditions in vivo . The later appearance of microspheres in intestinal lymph has also been measured by flow cytometry . The protein preparations used in these experiments included bovine serum albumin (bSA), human immunoglobulin G (hIgG), secretory immunoglobulin A (hIgA), bovine growth hormone (bGH) and bGH complexed with an IgG antibody raised against bGH (bGH-Ab) . Selectivity in binding of these microspheres to M cells, determined by confocal microscopy, was bGH < bSA < hIgG (mice) and bGH < bGH-Ab (rats and mice) . A similar selectivity was seen for microsphere entry into M cells (bGH < bSA < hIgG; bGH < bGH-Ab) . The appearance of protein-coated microspheres in rat mesenteric lymph showed a similar selectivity to that found for binding and entry into M cells (bGH < bGH-Ab) . This latter selectivity was also found for hIgA-coated microspheres (bSA < hIgA) . Preservation of transport selectivity throughout transcytosis highlights the unique importance of the M cell surface as being the primary site determining which type of antigen can be presented subsequently to the gut immune system . The possibility that this is a transient or phasic property of the M cell surface and that this could have physiological relevance is also discussed.

Histochem Cell Biol, 1995 Sep, 104(3), 185 - 9
Immunohistochemical localization of NAD glycohydrolase in human and rabbit tissues; Han MK et al.; NAD glycohydrolase (NADase) is present in many organisms from bacteria to mammals . In any given organism, this enzyme is ubiquitous in many tissues . However, its precise localization and its physiological significance have not been defined . We have determined the distribution of NADase in normal human and rabbit tissues by immunoblotting and immunohistochemistry, using a polyclonal antibody raised in goats . Immunoblot analyses revealed that NADase was highly expressed in the heart, lung, stomach, and liver tissues of the rabbit . From immunohistochemical studies of NADase, high concentrations in both human and rabbit tissues were found in hepatocytes and sinusoidal lining cells, sinus histiocytes of the lymph node, spleen and thymus, glomerular capillary endothelial cells of the kidney, cardiac muscle, endothelium of blood vessels, and erythrocytes.

J Am Anim Hosp Assoc, 1995 Sep-Oct, 31(5), 397 - 401
Exophthalmos associated with frontal sinus osteomyelitis in a puppy; Grahn BH et al.; A three-month-old, male Great Dane puppy developed progressive left exophthalmos, epiphora, and swelling of the left frontal bone . Radiographs revealed obliteration of the left frontal sinus by a bone-like density, and lateral sinus wall thickening with extension into the left orbit . On surgical exploration and trephination, the left frontal sinus was filled with soft bone which contained multiple pockets of mucopurulent material . Cytologic examination confirmed the presence of a large number of neutrophils, osteoclasts, and osteoblasts; and both extracellular and intracellular, filamentous, beaded bacteria . The involved bone was debrided, and the defects in the orbital wall and sinus were reconstructed successfully with a temporalis muscle flap.

Antimicrob Agents Chemother, 1995 Sep, 39(9), 2164 - 6
Sequence and analysis of the rpoB gene of Mycobacterium smegmatis; Hetherington SV et al.; The rpoB gene encodes the beta subunit of the DNA-dependent RNA polymerase of bacteria . Mutations in defined areas result in resistance to rifampin . Mycobacterium smegmatis is naturally resistant to rifampin, but analysis of the rpoB gene revealed no identifiable rifampin resistance mutations . Another mechanism of resistance may be present.

Antimicrob Agents Chemother, 1995 Sep, 39(9), 2073 - 7
Comparison of activities of rifapentine and rifampin against Mycobacterium tuberculosis residing in human macrophages; Mor N et al.; The activities of rifapentine and rifampin against Mycobacterium tuberculosis residing in human monocyte-derived macrophages were determined . The MICs and MBCs of rifapentine for intracellular bacteria were two- to fourfold lower than those of rifampin . For extracellular bacteria, this difference was less noticeable . Nevertheless, the more favorable pharmacokinetics of rifapentine over rifampin was addressed in other experimental models . These models showed substantial differences after short pulsed exposures of the infected macrophages to the drugs and when the infected macrophages were exposed to changing drug concentrations that imitated the pharmacokinetic curves observed in blood . Once-a-week exposures to rifapentine concentrations equivalent to those attained in blood after one 600-mg dose resulted during the first week in a dramatic decline in the number of bacteria, and this decline was maintained at a minimal level for a period of four weeks . The results of this study have shown the suitability of rifapentine for intermittent-treatment regimens . The prolonged effect of rifapentine found in this study may be associated with high ratios of intracellular accumulation, which were four- to fivefold higher than those found for rifampin . Further studies on the intracellular distribution of rifamycins and on the sites of actual interaction between the drugs and bacteria residing in macrophages are necessary.

Res Vet Sci, 1995 Sep, 59(2), 128 - 35
Effects of the severity and duration of lesions on the primary and anamnestic humoral responses of sheep to Dichelobacter nodosus and observations of natural resistance to footrot; Whittington RJ et al.; In a flock of 137 sheep naturally infected with Dichelobacter nodosus the severity of the lesions was the principal factor associated with the humoral response early in the period of spread of D . nodosus, underrun lesions having the greatest effect . However, after five to six weeks, the duration of underrun lesions rather than their severity or number primarily influenced the response . Sheep first affected late in the period of spread had fewer affected feet, milder lesions and a lower humoral response than those affected earlier . An anamnestic humoral response was stimulated by injecting membrane-protein antigen of D nodosus subcutaneously 18 weeks after the sheep had been treated parenterally with antibiotics and antiseptic footbathing . The anamnestic response was related to the antibody level reached during the infection phase, and hence with the duration and severity of the lesions, and with the residual antibody level at the time of the anamnestic challenge, suggesting that the population of memory B cells specific for D nodosus was proportional to the size of the originally activated B cell population . Even after allowing for differences between the duration and severity of the lesions differential responses were detectable among the sheep . Primary and anamnestic responses of a non-specific nature occurred in control sheep.

Res Vet Sci, 1995 Sep, 59(2), 102 - 5
Relationship between clinical manifestations of footrot and specific DNA products of Dichelobacter nodosus amplified through PCR; Liu D et al.; A total of 141 Dichelobacter nodosus isolates from 46 merino sheep farms with various clinical forms of footrot was examined by the gelatin gel test and the polymerase chain reaction (PCR) using virulent (Vf2 and Vr2) and benign (Bf and Br) specific primers . Isolates from sheep with virulent and high intermediate footrot usually produced relatively thermostable proteases, but a decreasing proportion of the isolates from sheep with medium and low intermediate or benign footrot had thermostable proteases, as determined by the gelatin gel test . The amplification by PCR of a major band of 857 bp by Vf2 and Vr2 was often associated with isolates from the more virulent forms of footrot whereas the presence of a major band of 1300 bp by Vf2 and Vr2 and/or a band of 609 bp by Bf and Br was associated with isolates from less virulent forms of footrot . Nevertheless, the virulent and benign gene regions represented by Vf2 and Vr2 and Bf and Br are only two of the many factors involved in determining the virulence of D nodosus . As a result the relationship observed between the clinical manifestations of footrot and specific DNA products amplified by PCR was not complete.

Cell Transplant, 1995 Sep-Oct, 4(5), 455 - 77
Infectious disease transmission through cell, tissue, and organ transplantation: reducing the risk through donor selection; Eastlund T; The incidence of cell transplant-transmitted infection is unknown and can only be inferred from prospective studies--that have not yet been performed and reported . The possibility of donor-to-recipient disease transmission through cell transplant therapy can be considered by reviewing the risk associated with other transplanted tissues and organs . Viral, bacterial, and fungal infections have been transmitted via transplantation of organs, tissue allografts such as bone, skin, cornea, and heart valves, and cell such as islets, hematopoietic stem cells, and semen . Several types of protozoan and worm parasites have been transferred via organ transplants . Bone allografts have transmitted hepatitis, tuberculosis, and human immunodeficiency virus (HIV-1) . Corneas have transmitted rabies, Creutzfeldt-Jakob disease (CJD), hepatitis B (HBV), cytomegalovirus (CMV), herpes simplex virus (HSV), bacteria, and fungi . Heart valves have been implicated in transmitting tuberculosis and hepatitis B . HIV-1 and CMV seroconversion has been reported in patients receiving skin from seropositive donors . CJD has been transmitted by dura and pericardium transplants . Over the past several years, improvements in donor screening criteria, such as excluding potential donors with infection and those with behaviors risky for HIV-1 and hepatitis infection, and introduction of new donor blood tests have greatly reduced the risk of HIV-1 and hepatitis and may have nearly eliminated the risk of tuberculosis and CJD . Prior to use, many tissues are exposed to antibiotics, disinfectants, and sterilants, which further reduce or remove the risk of transmitted disease . Because organs, cells, and some tissue grafts cannot be subjected to sterilization steps, the risk of infectious disease transmission remains and thorough donor screening and testing is especially important.

Izv Akad Nauk Ser Biol, 1995 Sep-Oct, (5), 579 - 85
{The anti-infective properties of mammalian earwax}; Sokolov VE et al.; The cerumen (earwax) of some mammals possesses antistaphylococcal, antimicrococcal and antiherpes activities . The cerumen of two thirds of individuals, irrespective of their species identity and sex, has antiviral properties . The mean chemotherapeutical index in the studied groups follows a significantly decreasing sequence: dogs, humans without signs of herpes infections, rabbits, and humans with clinically expressed herpes infection . Cerumen of almost 25% of humans of the compared groups displays the immunostimulating activity . The cerumen of all studied individuals contains yeast-like fungi . A suggestion is put forward that the products of their metabolism stimulate local release of interferon-like substances by the lymphoid tissue in the cerumen.

Biophys J, 1995 Sep, 69(3), 1100 - 4
Femtosecond probe of structural analogies between chlorosomes and bacteriochlorophyll c aggregates; Savikhin S et al.; Bacteriochlorophyll c pigments extracted from light harvesting chlorosomes in green photosynthetic bacteria are known to self-assemble into aggregates whose electronic spectroscopy resembles that of intact chlorosomes . Femtosecond optical experiments reveal that the chlorosomes and their reconstituted aggregates exhibit closely analogous internal energy transfer kinetics and exciton state evolution . These comparisons furnish compelling new evidence that proteins do not exert a major local role in the BChl c antenna pigment organization of intact chlorosomes.

Curr Opin Rheumatol, 1995 Sep, 7(5), 455 - 8
Kawasaki syndrome; Meissner HC et al.; Although a general consensus on the etiology of Kawasaki syndrome has not been reached, increasing evidence suggests that this illness represents a response to a superantigen . This conclusion is based on the observations of the immunologic changes that characterize the acute stages of illness as well as on the demonstrated association with toxin-producing bacteria in the pharynx and gastrointestinal tract . Therapy with intravenous gamma globulin and high-dose aspirin remains the standard of care for acute disease . Long-term follow-up of increasing numbers of children has confirmed that few properly treated children are at risk for the development of coronary artery abnormalities due to this illness.

J Bacteriol, 1995 Sep, 177(18), 5346 - 9
Methionine inhibits developmental aggregation of Myxococcus xanthus by blocking the biosynthesis of S-adenosyl methionine; Shi W et al.; Previous studies showed that high concentrations of methionine (> 1 mM) inhibited aggregation and fruiting body formation in Myxococcus xanthus (E . Rosenberg, D . Filer, D . Zafriti, and S . H . Kindler, J . Bacteriol . 115: 29-34, 1973, and J . M . Campos and D . R . Zusman, Proc . Natl . Acad . Sci . USA 72:518-522, 1975) . However, the mechanism for the inhibition was unclear . In this study, we found that high levels of methionine inhibited the biosynthesis of S-adenosylmethionine (SAM) and that reduced intracellular levels of SAM are correlated with defective chemotactic movements and reduced developmental gene expression . In addition, we found that methionine analogs and high concentrations of amino acids which are known to affect SAM synthesis in other bacteria, such as threonine, lysine, and isoleucine, also caused reduced cellular levels of SAM and blocked fruiting body formation in M . xanthus . These results indicate that SAM is required for development of M . xanthus and the inhibitory effect of methionine on development results, at least in part, from its blocking of the biosynthesis of SAM.

J Bacteriol, 1995 Sep, 177(18), 5327 - 33
Unique cholesteryl glucosides in Helicobacter pylori: composition and structural analysis; Hirai Y et al.; A chloroform-methanol-extracted lipid of Helicobacter pylori was studied . Three kinds of glycolipids, accounting for about 25% (wt/wt) of the total lipid, were detected and identified to be cholesteryl glucosides . The structures of two of them were determined to be cholesteryl-alpha-D-glucopyranoside and cholesteryl-6-O-tetrade-canoyl-alpha-D-glucopyranoside, and the plausible structure of the third one was identified as cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside . Cholesteryl glucosides are very rare in animals and bacteria . Furthermore, those in H . pylori had an alpha-glycosidic linkage, which is rather unusual for natural glycosides, and a phosphate-linked cholesteryl glycoside like the cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside has not been reported previously . As the cholesterol glucosides were detected in strains obtained from diverse geographical locations, the presence of cholesteryl glucosides in H . pylori is a very unique and a characteristic feature of the species . These findings add a new facet to the physiology and biochemistry, especially the cholesterol and glucose metabolism, of H . pylori . Furthermore, the cholesteryl glucosides of H . pylori showed hemolytic activities.

Am J Gastroenterol, 1995 Sep, 90(9), 1526 - 8
Reversible hypoprothrombinemia in a patient with primary biliary cirrhosis treated with rifampicin; Van Steenbergen W et al.; A patient with primary biliary cirrhosis (PBC) developed marked hypoprothrombinemia with decreased concentrations of the vitamin K-dependent coagulation factors VII, IX, and X during treatment with rifampicin . The coagulation abnormalities were easily corrected by administration of vitamin K . Different mechanisms may be involved, such as a decreased production of menaquinones by intestinal bacteria, a warfarin-like effect by inhibition of the vitamin K epoxide reductase, or an increased oxidative degradation of vitamin K as a result of hepatic microsomal enzyme stimulation . Whatever the mechanism involved, the appearance of this complication in a patient with PBC probably points to the importance of a pre-existing poor vitamin K status . Patients with PBC, treated with rifampicin, should have a regular monitoring of their vitamin K status . Adequate vitamin substitution should be administered, if necessary.

Hepatology, 1995 Sep, 22(3), 887 - 95
N-ethyl-tauroursodeoxycholic acid, a novel deconjugation-resistant bile salt analogue: effects of acute feeding in the rat; Angelico M et al.; The purpose of this study was to investigate the physicochemical/biological properties and the effects of acute administration of N-ethyl-tauroursodeoxycholic acid in bile-fistula rats . In vitro determination of high-performance liquid chromatography mobility, octanol/ water partitioning, cholesterol solubilizing capacity, and sensitivity to enzyme deconjugation by bacteria and cholylglycine-hydroxylase were performed . In vivo determination of the following was also performed: (1) maximum secretory rate (SRmax) and choleretic/secretory properties during intravenous (IV) administration; (2) site/ extent of absorption, effects on bile flow, lipid secretion, and biotransformations after intraduodenal infusion . N-ethyl-tauroursodeoxycholate has a lipophilicity slightly higher than tauroursodeoxycholate, close to taurocholate, and similar cholesterol solubilizing capacity . Deconjugation of N-ethyl-tauroursodeoxycholate was 3.4 +/- 2.1% after 72 hours, that of tauroursodeoxycholate was 100% after 24 hours . During IV infusion of 300 nmol/min/ 100g, biliary secretion of N-ethyl-tauroursodeoxycholic and tauroursodeoxycholic acids averaged 185 +/- 76 (standard deviation) nmol/min/100 g and 221 +/- 77 nmol/min/ 100 g (not significant) . Increasing infusion rates caused progressive enhancement of bile flow and bile salt secretion until the SRmax was reached (1,305 +/- 240 nmol/min/ 100 g for N-ethyl-tauroursodeoxycholic acid and 3,240 nmol/min/100 g for tauroursodeoxycholate) . The two bile salts were similarly choleretic . IV feeding of N-ethyl-tauroursodeoxycholic promoted a greater lipid secretion than tauroursodeoxycholate . After intraduodenal feeding of 800 mumol, 38.8 +/- 14.0% and 43.4 +/- 12.4% of the two bile salts were recovered in bile . No unconjugated bile salts nor unusual metabolites were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastroenterology, 1995 Sep, 109(3), 692 - 700
Comparison of Helicobacter mustelae and Helicobacter pylori adhesion to eukaryotic cells in vitro; Gold BD et al.; BACKGROUND & AIMS: Bacterial adhesion to mucosal surfaces is an important pathogenic mechanism for Helicobacter-induced gastritis . The aims of this study were to compare binding of selected Helicobacter mustelae and Helicobacter pylori strains to lipids extracted from HEp-2, Chinese hamster ovary, human embryonic lung cells, and ferret gastrointestinal tissues as well as to intact tissue culture cells and to analyze the fatty acids of the receptor . METHODS: Thin-layer chromatography overlay binding and a receptor-based immunoassay detected adhesion of bacteria to commercial lipids and to individual species within the lipid extracts . H . mustelae binding to tissue culture cells was performed by whole cell bacterial adhesion assay . RESULTS: H . mustelae and H . pylori both bound to phosphatidylethanolamine and lysophosphatidylethanolamine . Adhesion of H . mustelae to intact eukaryotic cells correlated with the amount of phosphatidylethanolamine . Binding of helicobacters was greater to lipids derived from ferret antrum compared with colon (P < 0.05) . Biochemical analysis suggested that heterogeneity in fatty acid composition of phosphatidylethanolamine could influence the degree of Helicobacter binding . CONCLUSIONS: Adhesion of Helicobacter strains correlates with the quantity of phosphatidylethanolamine present in the epithelial cell and with the differences in the fatty acid profile of the lipid.

Infect Immun, 1995 Sep, 63(9), 3609 - 20
Association of Legionella pneumophila with the macrophage endoplasmic reticulum; Swanson MS et al.; Legionella pneumophila replicates within a membrane-bounded compartment that is studded with ribosomes . In this study we investigated whether these ribosomes originate from the cytoplasmic pool or are associated with host endoplasmic reticulum (ER) . Immunofluorescence and electron microscopic localization studies of ER proteins in macrophages infected with L . pneumophila indicated that the bacteria reside in a compartment surrounded by ER . An L . pneumophila mutant that grows slowly in macrophages was slow to associate with host ER, providing genetic evidence in support of the hypothesis that this specialized vacuole is required for intracellular bacterial growth . Ultrastructural studies, in which the ER luminal protein BiP was labeled by immunoperoxidase cytochemistry, revealed that L . pneumophila replication vacuoles resemble nascent autophagosomes . Furthermore, short-term amino acid starvation of macrophages, which stimulated host autophagosomes . Furthermore, short-term amino acid starvation of macrophages, which stimulated host autophagy, increased association of the bacteria with the ER and enhanced bacterial growth . These results are compatible with the hypothesis that L . pneumophila exploits the autophagy machinery of macrophages to establish an intracellular niche favorable for replication.

Infect Immun, 1995 Sep, 63(9), 3245 - 52
Functional properties of nonhuman primate antibody to Porphyromonas gingivalis; Anderson DM et al.; The nonhuman primate (NHP) serves as a useful model for examining the host-parasite interactions in Porphyromonas gingivalis-associated periodontal disease . This study determined the influence of NHP sera on (i) the direct killing of P . gingivalis, (ii) P . gingivalis-induced superoxide anion (O2-) release from human polymorphonuclear leukocytes (PMNs), and (iii) the ability of PMNs to bind and phagocytize P . gingivalis . Three types of NHP sera were utilized: (i) normal or baseline sera; (ii) sera obtained after ligature-induced periodontitis; and (iii) sera obtained following active immunization with formalinized P . gingivalis . All assays were performed with or without the addition of human complement . Significantly more (P < 0.01) direct killing of P . gingivalis occurred with immunized sera and complement than with any of the other treatments . The sera from ligature-induced periodontitis NHPs had significantly less (P < 0.03) killing capacity than the baseline sera, which contained natural antibody produced to P . gingivalis colonization . Sera from immunized NHPs were used to opsonize P . gingivalis and caused significantly greater (P < 0.01) levels of O2- release from PMNs . Finally, the sera from immunized NHPs significantly enhanced (P < 0.009) the uptake of P . gingivalis by PMNs, although binding of the bacteria to PMNs was similar among all three serum types . Active immunization of NHPs with P . gingivalis elicited a functional antibody that enhanced direct killing, positively influenced the activation of PMNs, and enhanced the ability of PMNs to phagocytize P . gingivalis . Moreover, antibody produced as a sequela of progressing periodontitis appeared to lack these functions . A wide variability in functional capacity of the sera from individual NHPs, which may contribute to an individual's susceptibility to P . gingivalis-induced disease, was noted . This variability suggested that results from functional tests of serum antibody may aid in predicting host susceptibility to disease and response to therapy.

J Virol, 1995 Sep, 69(9), 5287 - 93
Expression of PE38 and IE2, viral members of the C3HC4 finger family, during baculovirus infection: PE38 and IE2 localize to distinct nuclear regions; Krappa R et al.; The pe38 gene of Autographa californica nuclear polyhedrosis virus represents one of the major early transcripts after viral infection . The function of the pe38 protein, which contains a C3HC4 zinc finger motif, is still not understood . We have raised polyclonal antiserum against the pe38 protein, PE38, produced in bacteria to investigate pe38 expression in the course of infection . A approximately 38-kDa polypeptide is first detectable at 2 h postinfection and decreases rapidly after 24 h . During the late phases of infection, a smaller protein of approximately 20 kDa which cross-reacts with the PE38-specific antiserum is visible at a constant level until 120 h postinfection . Since the pe38 gene shares a divergent promoter unit with the ie2 gene (formerly IEN), we have compared the expressions of the two genes . Polyclonal antibodies were raised against the bacterially expressed ie2 protein . The temporal expression pattern of the approximately 49-kDa ie2 protein is comparable to that of the approximately 38-kDa pe38 protein . Furthermore, both proteins are present in the nuclear fraction of A . californica nuclear polyhedrosis virus-infected Spodoptera frugiperda cells, but the approximately 38-kDa pe38 protein is also detectable in the cytoplasm while the smaller protein of approximately 20 kDa is exclusively present in the cytoplasmic fraction . Immunofluorescence analysis reveals that PE38 and IE2 localize to distinct regions within the nucleus mainly detected after transfection of pe38- and ie2-expressing constructs.

J Antibiot (Tokyo), 1995 Sep, 48(9), 929 - 36
Sulfobacins A and B, novel von Willebrand factor receptor antagonists . II . Structural elucidation; Kamiyama T et al.; Sulfobacins A and B are novel von Willebrand factor (vWF) receptor antagonists produced by Chryseobacterium sp . NR 2993 . The structures of sulfobacins A and B have been determined to be (2R,3R)-3-hydroxy-2-{(R)-3-hydroxy-15-methylhexadecanamido}-15- methylhexadecanesulfonic acid and (2R,3R)-3-hydroxy-15-methyl-2-{13-methyltetradecanamido}- hexadecanesulfonic acid, respectively, by various 2D NMR experiments and by methanolysis . The absolute configurations of the sulfobacins were determined by a modified MOSHER's method . The structures are related to sulfonolipids, major components of the cell envelope of gliding bacteria of the genus Cytophaga.

Can J Microbiol, 1995 Sep, 41(9), 849 - 54
The two overlapping Azospirillum brasilense upstream activator sequences have differential effects on nifH promoter activity; Passaglia LM et al.; The Azospirillum brasilense nifH promoter is positively controlled by the NifA protein bound to the upstream activator sequences (UASs) . Two overlapping UASs located at -191 and -182 were identified with the consensus TGT-N10-ACA motif . The role of the two UASs of Azospirillum brasilense nifH promoter was examined by introducing base substitutions in the NifA binding sites . Both the promoter down phenotype of a mutation in UAS2 and increased activation when UAS1 was mutated reveal that the integrity of the UAS2 is required for the efficient activation of nifH promoter . This atypical NifA-binding site may represent a region interacting with two NifA dimers.

J Eukaryot Microbiol, 1995 Sep-Oct, 42(5), 593 - 603
Primary structure of the hydrogenosomal malic enzyme of Trichomonas vaginalis and its relationship to homologous enzymes; Hrdy I et al.; The complete nucleotide sequence has been established for two genes (maeA and maeB) coding for different subunits of the hydrogenosomal malic enzyme {malate dehydrogenase (decarboxylating) EC 1.1.1.39} of Trichomonas vaginalis . Two further genes (maeC and maeD) of this enzyme have been partially sequenced . The complete open reading frames code for polypeptides of 567 amino acids in length . These two open reading frames are similar with less than 12 percent pairwise nucleotide differences and less than 9 percent pairwise amino acid differences . The open reading frames of the two partially sequenced genes correspond to the amino-terminal part of the polypeptides coded and are similar to the corresponding parts of the completely sequenced ones . The deduced translation products of the two complete genes differ in their calculated pI values by 1.5 pH unit . The genes code for polypeptides which contain 12 or 11 amino-terminal amino-acyl residues not present in the proteins isolated from the cell . Other hydrogenosomal enzymes also have similar amino-terminal extensions which probably play a role in organellar targeting and translocation of the newly synthesized polypeptides . A comparison of 19 related enzymes from bacteria and eukaryotes with the maeA product revealed 34-45 percent amino acid identity . Phylogenetic reconstruction based on nonconservative amino acid differences with maximum parsimony (phylogenetic analysis using parsimony, PAUP) and distance based (neighbor-joining, NJ) methods showed that the T . vaginalis enzyme is the most divergent of all eukaryotic malic enzymes, indicating its long independent evolutionary history.

Fetal Diagn Ther, 1995 Sep-Oct, 10(5), 279 - 85
Fetal haematological response to intra-uterine infection in preterm prelabour amniorrhexis; Carroll SG et al.; The value of fetal haematological indices in the prediction of intra-uterine infection in 91 cases of preterm prelabour amniorrhexis was examined . Cordocentesis and amniocentesis were performed for the diagnosis of intra-uterine infection . The patients were subsequently divided into three groups, depending on the results of fetal blood and amniotic fluid cultures . In group 1 there were 53 patients with negative fetal blood and amniotic fluid cultures, group 2 consisted of 22 patients with negative fetal blood, but positive amniotic fluid cultures, and in group 3 there were 16 patients with positive fetal blood cultures . The mean leucocyte and neutrophil counts in all three groups were significantly higher than normal, and in group 3 the values were significantly higher than in group 1 . The leucocyte and neutrophil counts were above the 95th centile of the normal range in 58% (22 cases) and 66% (25 cases), respectively, of the 38 cases with positive fetal blood and/or amniotic fluid cultures and in only 15% (8 cases) and 13% (7 cases), respectively, of the 53 patients with no infection . There were no significant differences between the groups, between the patients with amniorrhexis or for normal haemoglobin concentration, platelet count, or lymphocyte count . In the majority of the cases with positive fetal blood and/or amniotic fluid cultures, there is fetal leucocytosis . Since the results of the fetal leucocyte and neutrophil counts are available within a few minutes after cordocentesis, it would be reasonable to give antibiotics to all patients with a fetal leucocyte count above the 95th centile.

Transfusion, 1995 Sep, 35(9), 769 - 72
Transfusion-transmitted human parvovirus B19 infection in a thalassemic patient; Zanella A et al.; BACKGROUND: Human parvovirus (HPV) B19 infection has been shown to be transmissible by clotting factor concentrates, most often resulting in asymptomatic seroconversion . So far, no case of B19 transmission due to single-donor transfusion has been documented . CASE REPORT: A case of transfusion-transmitted HPV B19 infection in a 22-year-old female thalassemia major patient is described . She presented with an aplastic crisis; this was followed 1 week later by transitory heart failure and acute tricuspid incompetence . The echocardiogram revealed a grade III tricuspid regurgitation and a floating vegetation on the atrial face of the tricuspid lateral leaflet . The tricuspid regurgitation and vegetation spontaneously disappeared within 15 days . Blood cultures for bacteria were repeatedly negative . IgM anti-HPV B19 seroconversion was documented in the acute phase . B19 DNA was detected by polymerase chain reaction and remained detectable up to 4 months after diagnosis . High-titer IgM anti-HPV and B19 DNA were also found in serum samples collected at the time of donation from one of the donors of the blood transfused before the onset of clinical symptoms . CONCLUSION: This case documents the transmission of HPV B19 by the transfusion of 1 red cell unit and the occurrence of possible transient cardiac involvement in this infectious complication.

Microbiol Rev, 1995 Sep, 59(3), 481 - 505
Regulation of human immunodeficiency virus type 1 and cytokine gene expression in myeloid cells by NF-kappa B/Rel transcription factors; Roulston A et al.; CD4+ macrophages in tissues such as lung, skin, and lymph nodes, promyelocytic cells in bone marrow, and peripheral blood monocytes serve as important targets and reservoirs for human immunodeficiency virus type 1 (HIV-1) replication . HIV-1-infected myeloid cells are often diminished in their ability to participate in chemotaxis, phagocytosis, and intracellular killing . HIV-1 infection of myeloid cells can lead to the expression of surface receptors associated with cellular activation and/or differentiation that increase the responsiveness of these cells to cytokines secreted by neighboring cells as well as to bacteria or other pathogens . Enhancement of HIV-1 replication is related in part to increased DNA-binding activity of cellular transcription factors such as NF-kappa B . NF-kappa B binds to the HIV-1 enhancer region of the long terminal repeat and contributes to the inducibility of HIV-1 gene expression in response to multiple activating agents . Phosphorylation and degradation of the cytoplasmic inhibitor I kappa B alpha are crucial regulatory events in the activation of NF-kappa B DNA-binding activity . Both N- and C-terminal residues of I kappa B alpha are required for inducer-mediated degradation . Chronic HIV-1 infection of myeloid cells leads to constitutive NF-kappa B DNA-binding activity and provides an intranuclear environment capable of perpetuating HIV-1 replication . Increased intracellular stores of latent NF-kappa B may also result in rapid inducibility of NF-kappa B-dependent cytokine gene expression . In response to secondary pathogenic infections or antigenic challenge, cytokine gene expression is rapidly induced, enhanced, and sustained over prolonged periods in HIV-1-infected myeloid cells compared with uninfected cells . Elevated levels of several inflammatory cytokines have been detected in the sera of HIV-1-infected individuals . Secretion of myeloid cell-derived cytokines may both increase virus production and contribute to AIDS-associated disorders.

Microbiol Rev, 1995 Sep, 59(3), 423 - 50
mRNA stability in mammalian cells; Ross J; This review concerns how cytoplasmic mRNA half-lives are regulated and how mRNA decay rates influence gene expression . mRNA stability influences gene expression in virtually all organisms, from bacteria to mammals, and the abundance of a particular mRNA can fluctuate manyfold following a change in the mRNA half-life, without any change in transcription . The processes that regulate mRNA half-lives can, in turn, affect how cells grow, differentiate, and respond to their environment . Three major questions are addressed . Which sequences in mRNAs determine their half-lives? Which enzymes degrade mRNAs? Which (trans-acting) factors regulate mRNA stability, and how do they function? The following specific topics are discussed: techniques for measuring eukaryotic mRNA stability and for calculating decay constants, mRNA decay pathways, mRNases, proteins that bind to sequences shared among many mRNAs {like poly(A)- and AU-rich-binding proteins} and proteins that bind to specific mRNAs (like the c-myc coding-region determinant-binding protein), how environmental factors like hormones and growth factors affect mRNA stability, and how translation and mRNA stability are linked . Some perspectives and predictions for future research directions are summarized at the end.

Eur J Biochem, 1995 Sep 1, 232(2), 552 - 7
Structures of the O-specific polysaccharide chains of Pectinatus cerevisiiphilus and Pectinatus frisingensis lipopolysaccharides; Senchenkova SN et al.; Mild acid hydrolysis of the smooth-type lipopolysaccharide (LPS) of Pectinatus frisingensis afforded no polysaccharide but monomeric 6-deoxy-L-altrose (L-6dAlt) which was identified by anion-exchange chromatography in borate buffer, GLC/MS, 1H-NMR spectroscopy, and optical rotation . LPS was degraded with alkali under reductive conditions to give a completely O-deacylated polysaccharide, which was studied by methylation analysis, 1H-NMR and 13C-NMR spectroscopy, including sequential, selective spin-decoupling, two-dimensional correlation spectroscopy (COSY), COSY with relayed coherence transfer, two-dimensional heteronuclear 13C, 1H-COSY, one-dimensional NOE and two-dimensional rotating-frame NOE spectroscopy . It was found that the O-specific polysaccharide chain of P . frisingensis LPS is a homopolymer of 6-deoxy-L-altrofuranose built up of tetrasaccharide-repeating units having the following structure: {sequence: see text} Similarly, mild acid degradation of smooth-type LPS of Pectinatus cerevisiiphilus resulted in depolymerisation of the polysaccharide chain to give a disaccharide consisting of D-glucose and D-fucose . Study of the disaccharide by methylation analysis and alkali-degraded LPS by one-dimensional and two-dimensional 1H-NMR and 13C-NMR spectroscopy showed that the O-specific polysaccharide of P . cerevisiiphilus has the following structure: -->2)-beta-D-Fucf-(1-->2)-alpha-D-Glcp-(1-->.

Carcinogenesis, 1995 Sep, 16(9), 2069 - 74
Nitric oxide and ethylnitrosourea: relative mutagenicity in the p53 tumor suppressor and hypoxanthine-phosphoribosyltransferase genes; Felley-Bosco E et al.; Nitric oxide (NO) is a cellular messenger which is mutagenic in bacteria and human TK6 cells and induces deamination of 5-methylcytosine (5meC) residues in vitro . The aims of this study were: (i) to investigate whether NO induces 5meC deamination in codon 248 of the p53 gene in cultured human bronchial epithelial cells (BEAS-2B); and (ii) to compare NO mutagenicity to that of ethylnitrosourea (ENU), a strong mutagen . Two approaches were used: (i) a novel genotypic assay, using RFLP/PCR technology on purified exon VII sequence of the p53 gene; and (ii) a phenotypic (HPRT) mutation assay using 6-thioguanine selection . BEAS-2B cells were either exposed to 4 mM DEA/NO (Et2N{N2O2}Na, an agent that spontaneously releases NO into the medium) or transfected with the inducible nitric oxide synthase (iNOS) gene . The genotypic mutation assay, which has a sensitivity of 1 x 10(-6), showed that 4 mM ENU induces detectable numbers of G --> A transitions in codon 248 of p53 while 5-methylcytosine deamination was not detected in either iNOS-transfected cells or cells exposed to 4 mM DEA/NO . Moreover, ENU was dose-responsively mutagenic in the phenotypic HPRT assay, reaching mutation frequencies of 24 and 96 times that of untreated control cells at ENU concentrations of 4 and 8 mM respectively; by contrast, 4 mM DEA/NO induced no detectable mutations in this assay, nor were any observed in cells transfected with murine iNOS . We conclude that if NO is at all promutagenic in these cells, it is significantly less so than the ethylating mutagen, ENU.

Phytochemistry, 1995 Sep, 40(2), 355 - 65
Plant transglutaminases; Serafini-Fracassini D et al.; The identification procedures, the characteristics and the potential function of the recently detected plant transglutaminases, are discussed in the light of the knowledge of animal transglutaminases . The enzyme has been studied occasionally in lower organisms (bacteria, fungi and green algae) and more extensively in Angiosperms.

Microbiology, 1995 Sep, 141 ( Pt 9), 2149 - 56
Selective recovery of Streptosporangium fragile from soil by indirect immunomagnetic capture; Mullins PH et al.; A polyclonal antibody raised to Streptosporangium fragile spores reacted strongly and specifically with the immunizing strain and to a number of related species of Streptosporangium, as determined by dot immunoblotting . An indirect immunomagnetic capture method was developed for the recovery of the target organism from sterile and non-sterile soil, using sheep anti-rabbit M-280 Dynabeads . The effects of different soil blocking agents, antibody labelling concentrations and spore/Dynabead capture times on the recovery of S . fragile spores were investigated . Pre-blocking of antibody binding sites within the soil, with either 2% partially hydrolysed gelatin or 10% skimmed milk, was essential prior to immunomagnetic capture . Increasing the capture time from 15 to 60 min did not affect spore recovery; however, a 10-fold decline in the magnetic bead concentration did result in a significantly lower recovery of spores from soil . S . fragile was selectively enriched (1:190-fold) when present as a mixed population with Arthrobacter oxydans in sterile soil . The indirect immunomagnetic capture method was used to selectively recover S . fragile spores seeded into non-sterile soil, although some background binding of non-target bacteria was noted . The target was successfully recovered from a sterile soil microcosm after 14 d incubation and the capture rate was increased by the inclusion of an initial soil dispersion and biomass concentration procedure, using the ion-exchange resin Chelex 100.

Microbiology, 1995 Sep, 141 ( Pt 9), 2139 - 47
Nucleotide sequences of streptomycete 16S ribosomal DNA: towards a specific identification system for streptomycetes using PCR; Mehling A et al.; To facilitate the differential identification of the genus Streptomyces, the 16S rRNA genes of 17 actinomycetes were sequenced and screened for the existence of streptomycete-specific signatures . The 16S rDNA of the Streptomyces strains and Amycolatopsis orientalis subsp . lurida exhibited 95-100% similarity, while that of the 16S rDNA of Actinoplanes utahensis showed only 88% similarity to the streptomycete 16S rDNAs . Potential genus-specific sequences were found in regions located around nucleotide positions 120, 800 and 1100 . Several sets of primers derived from these characteristic regions were investigated as to their specificity in PCR-mediated amplifications . Most sets allowed selective amplification of the streptomycete rDNA sequences studied . RFLPs in the 16S rDNA permitted all strains to be distinguished.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1995 Sep, 80(3), 330 - 7
Human pulp response after partial pulpotomy with two calcium hydroxide products; Subay RK et al.; Twenty human permanent teeth were used to study the pulpal response of two calcium hydroxide products, Dycal and Pulpdent Multi-Cal, after partial pulpotomy . Teeth were extracted at 4 months, fixed, and prepared for histologic examination . All 10 teeth treated with Dycal showed complete soft tissue healing and bridge formation . No stained bacteria were seen throughout the serial sections . One tooth treated with Dycal showed acceptable histologic results, dentin deposition in the root canal . Six cases dressed with Pulpdent Multi-Cal showed acceptable histologic results, whereas four teeth showed severe inflammation or necrosis associated with bacterial penetration into the pulp tissue . Clinically, one tooth treated with Pulpdent Multi-Cal showed pulpal pain and was extracted at 90 days . Our data support the thesis that human permanent pulps will promote tissue healing and dentin bridge formation as long as bacterial microleakage is excluded.

Nucleic Acids Res, 1995 Aug 25, 23(16), 3181 - 8
The beta recombinase of plasmid pSM19035 binds to two adjacent sites, making different contacts at each of them; Rojo F et al.; The beta recombinase from plasmid pSM19035 catalyzes intramolecular site-specific recombination between two directly or inversely oriented six sites in the presence of a chromatin-associated protein (Hbsu, HU or HMG-1) . The six site is a DNA segment containing two binding sites (I and II) for beta protein dimers . We show that beta recombinase binds sequentially to both sites, having a different affinity for each one . Hydroxyl radical footprints show a different protection pattern at each site . Positions critical for beta protein binding have been identified by methylation interference and missing nucleoside assays . The results indicate that the protein recognizes each site in a different way . Comparison of the beta protein recombination site with that of DNA resolvases and DNA invertases of the Tn3 family, to which it belongs, shows that these sequences can be divided into two regions . One corresponds to the crossover point and is similar for all recombinases of the family . The other region differs in the different subfamilies and seems to have an architectural role in aligning the crossover sites at the synaptic complex . The different ways to assemble this complex could explain why each system leads to a particular recombination event: DNA resolution (resolvases), inversion (invertases) or both (beta recombinase).

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