Microbiological

Proc Natl Acad Sci U S A, 1999 Oct 26, 96(22), 12345 - 9
A protein residing at the subunit interface of the bacterial ribosome; Agafonov DE et al.; Surface labeling of Escherichia coli ribosomes with the use of the tritium bombardment technique has revealed a minor unidentified ribosome-bound protein (spot Y) that is hidden in the 70S ribosome and becomes highly labeled on dissociation of the 70S ribosome into subunits . In the present work, the N-terminal sequence of the protein Y was determined and its gene was identified as yfia, an ORF located upstream the phe operon of E . coli . This 12.7-kDa protein was isolated and characterized . An affinity of the purified protein Y for the 30S subunit, but not for the 50S ribosomal subunit, was shown . The protein proved to be exposed on the surface of the 30S subunit . The attachment of the 50S subunit resulted in hiding the protein Y, thus suggesting the protein location at the subunit interface in the 70S ribosome . The protein was shown to stabilize ribosomes against dissociation . The possible role of the protein Y as ribosome association factor in translation is discussed.

J Leukoc Biol, 1999 Oct, 66(4), 542 - 8
The actions of bacterial DNA on murine macrophages; Sester DP et al.; Murine macrophages are able to distinguish bacterial from mammalian DNA . The response is mimicked by single-stranded oligonucleotides containing unmethylated CG dinucleotides ("CpG" motifs) in specific sequence contexts . The dose-response curve for activation is influenced by variation in the sequence flanking the core CpG motif . CpG or bacterial DNA activates several signaling pathways in common with bacterial lipopolysaccharide (LPS), leading to induction of cytokine genes such as tumor necrosis factor alpha . Pretreatment with LPS causes desensitization to subsequent activation by CpG DNA . Both stimuli also cause cell cycle arrest in macrophages proliferating in response to the macrophage growth factor colony-stimulating factor-1 (CSF-1), but prevent apoptosis caused by growth factor removal . In part, cell cycle arrest by CpG DNA and LPS may be linked to rapid down-modulation of the CSF-1 receptor from the cell surface, a response that occurs in an all-or-nothing manner . The response of macrophages to CpG DNA has aspects in common with the DNA damage response in other cell types, which may provide clues to the underlying mechanism.

Immunobiology, 1999 Sep, 201(1), 120 - 32
The role of intestinal bacterial flora in the tuning of the T cell repertoire; Sawamura SA et al.; The role of the intestinal bacterial flora on the Vbeta repertoire was examined using the gnotobiotic murine model . The ratio of Vbeta6-positive T cells in the periphery of DBA/2 mice under SPF conditions was only 2.2% (mean, n = 4), since the cells were eliminated by the endogenous superantigen Mls(a) . However, the ratio in germ-free (GF) mice was 31.7% . Similarly, the contamination of the GF Mice with the intestinal flora from SPF mice reduced the ratio of Vbeta6 in GF mice from 22.9% to 13.7% . In contrast, in BALB/c mice (Mls(b)) in which Vbeta6 cells do not react with this endogenous superantigen, the ratio of Vbeta6 cells do not react with this endogenous superantigen, the ratio of Vbeta6 of SPF mice (15.4%, mean, n = 3) was found to be comparable to that of GF mice (15.6%, n = 3) . These data suggested that the absence of intestinal flora deteriorated a part of the Mls(a) determinant, which reacted with the Vbeta6 T cells and thereby eliminated them, thus resulting in an increase of these cells in GF mice . Moreover, the alloantigenicity of minor histocompatible alloantigen(s) (mHAg) in SPF mice, which was detected in H-2 identical MLR experiments and a murine graft-versus-host (GVH) model, was reduced in GF and decontaminated SPF mice, thus indicating that the intestinal flora upregulated the mHAg including a part of Mls determinant . These results therefore suggest that the intestinal flora plays a role in the upregulation of mHAg including a part of endogenous superantigen and the consequent tuning of the Vbeta repertoire.

Eur J Pediatr Surg, 1999 Aug, 9(4), 224 - 7
Bacterial translocation in short-bowel syndrome in rats; Schimpl G et al.; Massive intestinal resection results in short-bowel syndrome (SBS) and is associated with an increased risk of infectious complications mainly caused by the egress of intestinal bacteria to distant organs, a process termed bacterial translocation (BT) . The purpose of this experimental study in rats was to investigate in different models of SBS the impact of the type of intestinal resection on bacterial growth in the residual small bowel and on the occurrence of BT . SBS was created in 30 rats either by jejunal resection (JR), by ileal resection (IR) or by ileal resection including the ileocecal valve (IR+ICV) . 10 animals underwent only a sham laparotomy (SL) and served as controls . Two weeks after the operative procedure, intestinal bacterial colonization and BT to the portal vein, vena cava, mesenteric lymph nodes, liver and spleen were determined . All resected animals showed a decreased weight gain and a significant bacterial overgrowth in the residual small bowel compared to the SL group . BT occurred after SL in 12%, after JR in 70%, after IR in 58%, and was significantly less frequent (35%) after IR+ICV, respectively . These experimental findings suggest that BT in SBS might be promoted by the intestinal bacterial overgrowth in the residual bowel, and the incidence of BT seems to be related to the presence or absence of the ileocecal valve.

Eur J Pediatr Surg, 1999 Aug, 9(4), 220 - 3
Bacterial translocation is favored by the preservation of the ileocecal valve in experimental short bowel with total parenteral nutrition; Eizaguirre I et al.; Sepsis in short-bowel syndrome (SBS) is in part due to bacterial translocation (BT) . Parenteral nutrition (PN) is often necessary in SBS and promotes BT . The aim of this study was to asses the effect of the presence or absence of ileocecal valve (ICV) on BT in parenterally-fed rats with massive intestinal resection . Sixty-five adult Wistar rats underwent central venous cannulations and were randomly assigned to one of five groups receiving for ten days five treatment regimes: Sham (n = 17) standard rat chow + i.v . saline . PN (n = 17) fasting + PN . Res-Sham (n = 10) standard rat chow + i.v . saline + 80% gut resection . Res-PN (n = 11) fasting, PN + 80% gut resection . Res-ICV-PN (n = 10) fasting, PN + 80% gut resection including ICV . At the end of the experiment they were euthanized and mesenteric lymph nodes (MLN), spleen and peripheral and portal blood specimens were recovered and cultured . BT was found in 47% of PN animals, 91% of Res-PN rats, 100% of Res-Sham group and 60% of Res-ICV-PN animals, but not in Sham ones . 97% of BT+ animals had positive cultures in MLN and/or portal blood, whereas germs beyond liver were detected in 30% of Res-Sham, 37% of PN, 50% of Res-PN and 0% of Res-ICV-PN rats . The present study confirms that both massive intestinal resection and PN promote BT . In addition, it shows that animals deprived of ICV have lower incidence of BT in this setting than those with it and that the germs do not reach in them peripheral blood in the same proportions as in ICV-intact animals . These results suggest that the presence of an intact ICV favor BT in parenterally-fed rats with massive intestinal resection.

J Biol Chem, 1999 Oct 29, 274(44), 31236 - 44
Highly specific recognition of primer RNA structures for 2'-OH priming reaction by bacterial reverse transcriptases; Inouye S et al.; A minor population of Escherichia coli contains retro-elements called retrons, which encode reverse transcriptases (RT) to synthesize peculiar satellite DNAs called multicopy single-stranded DNA (msDNA) . These RTs recognize specific RNA structures in their individual primer-template RNAs to initiate cDNA synthesis from the 2'-OH group of a specific internal G residue (branching G residue) . The resulting products (msDNA) consist of RNA and single-stranded DNA, sharing hardly any sequence homology . Here, we investigated how RT-Ec86 recognizes the specific RNA structure in its primer-template RNA . On the basis of structural comparison with HIV-1 RT, domain exchanges were carried out between two E . coli RTs, RT-Ec86 and RT-Ec73 . RT-Ec86 (320 residues) and RT-Ec73 (316 residues) share only 71 identical residues (22%) . From the analysis of 10 such constructs, the C-terminal 91-residue sequence of RT-Ec86 was found to be essential for the recognition of the unique stem-loop structure and the branching G residue in the primer-template RNA for retron-Ec86 . Using the SELEX (systematic evolution of ligands by exponential enrichment) method with RT-Ec86 and primer RNAs containing random sequences, the identical stem-loop structure (including the 3-U loop) to that found in the retron-Ec86 primer-template RNA was enriched . In addition, the highly conserved 4-base sequence (UAGC), including the branching G residue, was also enriched . These results indicate that the highly diverse C-terminal region recognizes specific stem-loop structures and the branching G residue located upstream of the stem-loop structure . The present results with seemingly primitive RNA-dependent DNA polymerases provide insight into the mechanisms for specific protein RNA recognition.

Comp Biochem Physiol C Pharmacol Toxicol Endocrinol, 1999 Jul, 123(3), 217 - 23
Eicosanoids mediate nodulation reactions to bacterial infections in larvae of the butterfly, Colias eurytheme; Stanley DW et al.; Nodulation is the first, and qualitatively predominant, cellular defense reaction to bacterial infections in insects . Treating larvae of the butterfly Colias eurytheme with the eicosanoid biosynthesis inhibitor dexamethasone, strongly impaired nodulation reactions to bacterial infections . The influence of dexamethasone was reversed by treating infected insects with arachidonic acid, an eicosanoid precursor . An eicosanoid biosynthesis system in C . eurytheme larvae is documented . Specifically, the presence of eicosanoid-precursor polyunsaturated fatty acids in tissue phospholipids was determined, an intracellular phospholipase A2 that can release arachidonic acid from tissue phospholipids was recorded, and eicosanoid biosynthesis, registered as conversion of exogenous radioactive 20:4n-6 into eicosanoids, was observed . These findings support the hypothesis that eicosanoids mediate cellular immune responses to bacterial infections in these butterfly larvae, and more broadly, in most, if not all, insects.

Clin Infect Dis, 1999 Sep, 29(3), 536 - 43
Impact of bacterial pneumonia and Pneumocystis carinii pneumonia on human immunodeficiency virus disease progression . Pulmonary Complications of HIV Study Group; Osmond DH et al.; The course of pneumonia caused by pyogenic bacteria and Pneumocystis carinii was examined in a multicity cohort study of HIV infection . The median duration of survival among 150 individuals following initial bacterial pneumonia was 24 months, compared with 37 months among 299 human immunodeficiency virus (HIV)-infected control subjects matched by study site and CD4 lymphocyte count (P<.001) . For 152 subjects with P . carinii pneumonia, median survival was 23 months, compared with 30 months for 280 matched control subjects (P = .002) . Median durations of survival associated with the two types of pneumonia differed by only 47 days, despite a higher median CD4 lymphocyte count associated with bacterial pneumonia . These results suggest that both P . carinii pneumonia and bacterial pneumonia are associated with a significantly worse subsequent HIV disease course . The similarity of prognosis after one episode of bacterial pneumonia vs . an AIDS-defining opportunistic infection and the proportion of cases occurring in association with a CD4 lymphocyte count of >200 suggest that measures to prevent bacterial pneumonia should be emphasized.

Biochemistry, 1999 Oct 19, 38(42), 14077 - 87
Kinetics and interactions of molybdenum and iron-sulfur centers in bacterial enzymes of the xanthine oxidase family: mechanistic implications; Canne C et al.; For isoquinoline 1-oxidoreductase (IsoOr), the reaction mechanism under turnover conditions was studied by EPR spectroscopy using rapid-freeze methods . IsoOr displays several EPR-active Mo(V) species including the "very rapid" component found also in xanthine oxidase (XanOx) . For IsoOr, unlike XanOx or quinoline 2-oxidoreductase (QuinOr), this species is stable for about 1 h in the absence of an oxidizing substrate {Canne, C., Stephan, I., Finsterbusch, J., Lingens, F., Kappl, R., Fetzner, S., and Huttermann, J . (1997) Biochemistry 36, 9780-9790} . Under rapid-freeze conditions in the presence of ferricyanide the very rapid species behaves as a kinetically competent intermediate present only during steady-state turnover . To explain the persistence of the very rapid species in IsoOr in the absence of an added oxidant, extremely slow product dissociation is required . This new finding that oxidative conditions facilitate decay of the very rapid signal for IsoOr supports the mechanism of substrate turnover proposed by Lowe, Richards, and Bray {Lowe, D . J., Richards, R . L., and Bray, R . C . (1997) Biochem . Soc . Trans . 25, 774-778} . Additional stopped-flow data reveal that alternative catalytic cycles occur in IsoOr and show that the product dissociates after transfer of a single oxidizing equivalent from ferricyanide . In rapid-freeze measurements magnetic interactions of the very rapid Mo(V) species and the iron-sulfur center FeSI of IsoOr and QuinOr were observed, proving that FeSI is located close to the molybdopterin cofactor in the two proteins . This finding is used to relate the two different iron-sulfur centers of the aldehyde oxidoreductase structure with the EPR-detectable FeS species of the enzymes.

Biochemistry, 1999 Oct 19, 38(42), 14036 - 44
The FinO repressor of bacterial conjugation contains two RNA binding regions; Ghetu AF et al.; Conjugative transfer of F-like plasmids in Escherichia coli is repressed by a plasmid-encoded protein, FinO . FinO blocks the translation of TraJ, a positive activator of transcription of genes required for conjugation . FinO binds a traJ antisense RNA, FinP, thereby protecting it from degradation, and catalyzes FinP-traJ mRNA hybridization . Interactions between these two RNAs are predicted to block the traJ ribosomal binding site . In this paper, we use limited proteolysis, circular dichroism spectroscopy, and an electrophoretic mobility shift assay to map the regions within FinO that are required for interactions with RNA . Our results show that FinO is largely helical, binds to its highest affinity binding site within FinP as a monomer, and contains two distinct RNA binding regions, one of which is localized between residues 26 and 61, and a second which is localized between residues 62 and 186.

Biochemistry, 1999 Oct 19, 38(42), 13780 - 6
A low-redox potential heme in the dinuclear center of bacterial nitric oxide reductase: implications for the evolution of energy-conserving heme-copper oxidases; Gronberg KL et al.; Bacterial nitric oxide reductase (NOR) catalyzes the two-electron reduction of nitric oxide to nitrous oxide . It is a highly diverged member of the superfamily of heme-copper oxidases . The main feature by which NOR is distinguished from the heme-copper oxidases is the elemental composition of the active site, a dinuclear center comprised of heme b(3) and non-heme iron (Fe(B)) . The visible region electronic absorption spectrum of reduced NOR exhibits a maximum at 551 nm with a distinct shoulder at 560 nm; these are attributed to Fe(II) heme c (E(m) = 310 mV) and Fe(II) heme b (E(m) = 345 mV), respectively . The electronic absorption spectrum of oxidized NOR exhibits a characteristic shoulder around 595 nm that exhibits complex behavior in equilibrium redox titrations . The first phase of reduction is characterized by an apparent shift of the shoulder to 604 nm and a decrease in intensity . This is due to reduction of Fe(B) (E(m) = 320 mV), while the subsequent bleaching of the 604 nm band represents reduction of heme b(3) (E(m) = 60 mV) . This separation of redox potentials (>200 mV) allows the enzyme to be poised in the three-electron reduced state for detailed spectroscopic examination of the Fe(III) heme b(3) center . The low midpoint potential of heme b(3) represents a thermodynamic barrier to the complete (two-electron) reduction of the dinuclear center . This may avoid formation of a stable Fe(II) heme b(3)-NO species during turnover, which may be an inhibited state of the enzyme . It would also appear that the evolution of significant oxygen reducing activity by heme-copper oxidases was not simply a matter of the substitution of copper for non-heme iron in the dinuclear center . Changes in the protein environment that modulate the midpoint redox potential of heme b(3) to facilitate both complete reduction of the dinuclear center (a prerequisite for oxygen binding) and rapid heme-heme electron transfer were also necessary.

Plant Mol Biol, 1999 Aug, 40(6), 977 - 83
Construction and characterization of a common bean bacterial artificial chromosome library; Vanhouten W et al.; We have constructed a common bean (Phaseolus vulgaris L.) bacterial artificial chromosome (BAC) library consisting of 33,792 clones and an estimated 3- to 5-fold coverage of the common bean genome . Leaf nuclei were used as the source for high-molecular-weight DNA, and an endonuclease/methylase competition assay was employed to partially cleave the DNA . The library was screened with a number of nuclear and mitochondrial probes . Each nuclear probe identified at least two BACs with an average insert size of ca . 100 kb . Only 26 clones were identified after hybridizing with mitochondrial probes, indicating contamination with organellar sequences is low . Numerous clones could be identified after screening the library with two repetitive probes flanking the nuclear fertility restorer Fr . Intriguingly, 12 clones appeared to hybridize to both markers, and restriction analysis of these clones revealed that they can be assembled into maximally four contigs, suggesting that these repetitive probes may be useful for the physical mapping of the Fr locus.

Biochim Biophys Acta, 1999 Oct 18, 1441(1), 51 - 60
cDNA cloning and bacterial expression of phospholipase A(2) inhibitor PLIalpha from the serum of the Chinese mamushi, Agkistrodon blomhoffii siniticus(1); Okumura K et al.; The cDNA encoding of a phospholipase A(2) inhibitor (PLIalpha) of the Chinese mamushi, Agkistrodon blomhoffii siniticus, was identified from a liver cDNA library by use of a probe prepared by polymerase chain reaction (PCR) on the basis of the amino acid sequence of PLIalpha . It encoded a polypeptide of 166 amino acid residues, including 19 residues of the signal sequence and 147 residues of the complete mature sequence of PLIalpha . The PLIalpha cDNA was subcloned into the expression vector pET-16b and used to transform Escherichia coli strain BL21(DE3)pLysS . The recombinant PLIalpha expressed as a fusion protein was solubilized and purified to homogeneity by use of a metal affinity resin . The purified PLIalpha fusion protein underwent folding to form a trimeric structure like the intact PLIalpha, and showed inhibitory activity against the group II acidic PLA(2) from A . blomhoffii siniticus venom; although its binding constant (1/K(i)) value was 30-fold lower than that of the natural PLIalpha . The elimination of the N-terminal additional peptide from the fusion protein resulted in a marked increase in the inhibition activity with a binding constant comparable to that of the natural PLIalpha against the acidic PLA(2) . Furthermore, the carbohydrate chains of the natural PLIalpha were found to play an important role in the inhibitory activity against the basic PLA(2).

Tex Heart Inst J, 1999, 26(3), 192 - 4
Technical aspects of mitral valve replacement with an allograft for acute bacterial endocarditis; Conklin LD et al.; Mitral valve replacement with a mitral valve allograft is receiving a resurgence of interest . We discuss the technical aspects of this procedure as it applies to cases of acute bacterial endocarditis infecting the mitral valve.

Genome Res, 1999 Oct, 9(10), 989 - 93
A resource of mapped human bacterial artificial chromosome clones; Cheung VG et al.; To date, despite the increasing number of genomic tools, there is no repository of ordered human BAC clones that covers entire chromosomes . This project presents a resource of mapped large DNA fragments that span eight human chromosomes at approximately 1-Mb resolution . These DNA fragments are bacterial artificial chromosome (BAC) clones anchored to sequence tagged site (STS) markers . This clone collection, which currently contains 759 mapped clones, is useful in a wide range of applications from microarray-based gene mapping to identification of chromosomal mutations . In addition to the clones themselves, we describe a database, GenMapDB , that contains information about each clone in our collection.

Hepatogastroenterology, 1999 Jul-Aug, 46(28), 2159 - 64
Obstructive jaundice promotes bacterial translocation in humans; Kuzu MA et al.; BACKGROUND/AIMS: Significant bacterial translocation was demonstrated following experimental biliary obstruction, however very little is known about the importance and the prevalence of gut-origin sepsis in obstructive jaundice patients . Therefore, the aim of this study was to investigate the concept of gut-origin sepsis in obstructive jaundiced patients and its clinical importance . METHODOLOGY: Twenty-one patients requiring laparotomy for obstructive jaundice (group I) and thirty patients operated on electively mainly for chronic cholecystitis (group II) were studied . Peritoneal swab, mesenteric lymph node, portal venous blood, liver wedge biopsy and bile were sampled for culture immediately after opening the peritoneum . Additionally, peripheral blood samples were taken pre- and post-operatively from all patients . Post-operatively, patients were monitored for infectious complications . RESULTS: The mean serum bilirubin concentration, gamma glutamyl transferase and alkaline phosphatase levels in jaundiced patients before therapeutic intervention were significantly higher than in control patients . Five patients demonstrated bacterial translocation in group I (24%), whereas only one did so in group II (3.5%, p < 0.05) . Septic complications were detected in three patients, but only in two with bacterial translocation in group I . There was one patient with bacterial translocation who had septic complication in group II . CONCLUSIONS: The present study demonstrated that obstructive jaundice significantly promotes bacterial translocation in humans, however, its clinical importance has yet to be defined.

Fertil Steril, 1999 Oct, 72(4), 730 - 2
Bacterial vaginosis and past chlamydial infection are strongly and independently associated with tubal infertility but do not affect in vitro fertilization success rates; Gaudoin M et al.; OBJECTIVE: To determine the incidence of active vaginal infection in women undergoing IVF, relate it to the cause of infertility, and investigate a relation with the outcome of fresh ET . DESIGN: Cross-sectional study . SETTING: Tertiary care infertility referral center . PATIENT(S): Two hundred eighty-six women who underwent 344 oocyte recovery procedures for IVF cycles between March 1997 and January 1998 . INTERVENTION(S): High vaginal swab specimens and endocervical swab specimens were obtained and ELISA serology was performed for detection of Chlamydia species on samples taken immediately before oocyte recovery . The results were related to the cause of infertility and the outcome parameters . MAIN OUTCOME MEASURE(S): Pregnancy rates . RESULT(S): Seropositivity for Chlamydia species and the presence of bacterial vaginosis both were strongly and independently associated with tubal disease . There was no difference in pregnancy rates in any of the groups regardless of their serologic status for chlamydial infection or current infection with bacterial vaginosis . CONCLUSION(S): This study provides further evidence of the pelvic pathogenicity of bacterial vaginosis . However, it shows that women who have bacterial vaginosis or who have been treated for chlamydial infection in the past achieve pregnancy rates with IVF treatment similar to those of women who have no evidence of such infections.

Anaesth Intensive Care, 1999 Oct, 27(5), 493 - 6
Bacterial contamination of propofol in the operating theatre; Soong WA; There have been several reports of propofol becoming extrinsically contaminated with bacteria . These reports have usually related to infusions or delays in administration after the ampoule has been opened . This observational study was performed to examine bacterial contamination of propofol during usual practice in the operating theatres of a single large hospital group . One hundred samples of propofol were collected and cultured . Samples were taken immediately after administration in cases where the delay between opening the ampoule and administration was at least 15 minutes . The samples were classified according to whether the propofol was kept in the ampoule or a syringe after opening the ampoule and whether the intended use was for a single patient or multiple patients . The time between opening the ampoule and administration was recorded . There were three positive bacterial cultures . These samples all came from ampoules used for more than one patient, without the later dose (does) being drawn into a syringe at the time the ampoule was opened . This common clinical practice, especially in paediatric anaesthesia, does not comply with the manufacturer's recommendations . The clinical significance of the bacterial contamination detected is not clear . It is recommended that propofol should be handled in an aseptic fashion and measures taken to minimize the risk of bacterial contamination.

Scand J Immunol, 1999 Oct, 50(4), 387 - 93
Participation of CD1 molecules in the presentation of bacterial protein antigens in humans; Ulanova M et al.; Human CD1 molecules, expressed on the surface of professional antigen-presenting cells (including dendritic cells, Langerhans' cells, B cells and activated monocytes) are structurally homologous to major histocompatibility complex (MHC) class I and class II molecules . CD1b and CD1c have been shown to present nonpeptide bacterial antigens to T cells . We hypothesized that CD1 molecules may also be involved in the presentation of bacterial protein antigens . Human peripheral blood mononuclear cells (PBMC) were exposed to two medically important proteins, tetanus toxoid (TT) and purified protein derivative (PPD), with and without murine monoclonal antibodies (MoAbs) specific for CD1a, CD1b and CD1c . All the MoAbs substantially inhibited the proliferative responses of PBMC to TT and PPD . Simultaneous interaction of CD1 and MHC class II molecules was even more inhibitory to these antigen-specific proliferative responses . In contrast, neither mixed lymphocyte reaction nor superantigen and mitogenic responses were affected by CD1-specific antibodies, indicating a certain restriction pattern in antigen presentation . Our findings suggest that, besides MHC class I and II molecules, there is a family of nonpolymorphic cell surface molecules that is able to present certain bacterial protein antigens to T cells.

J Heart Valve Dis, 1999 Sep, 8(5), 591 - 2
Fatal bacterial endocarditis following aortic valve replacement in a patient being treated with methotrexate; Wilkinson NM; A 41-year-old man being treated with methotrexate for psoriasis underwent aortic valve replacement . He subsequently developed fulminating bacterial endocarditis . Bacterial endocarditis occurs in 1-2% of cases after prosthetic valve replacement and has a high mortality . The long-term use of methotrexate and similar drugs is increasing in conditions such as psoriasis, rheumatoid arthritis and inflammatory bowel disease . Thus, more patients undergoing heart valve surgery will be taking these preparations for coexisting disease . As methotrexate increases the risk of infection, its perioperative use in these patients requires further evaluation.

Hum Gene Ther, 1999 Sep 20, 10(14), 2373 - 9
In vivo transfer of bacterial marker genes results in differing levels of gene expression and tumor progression in immunocompetent and immunodeficient mice; Lukacs KV et al.; To optimize gene delivery for the treatment of malignant mesothelioma, expression of the beta-galactosidase marker gene was examined in a murine model of intraperitoneal malignant mesothelioma . The beta-galactosidase gene was delivered to the peritoneal cavity of tumor-bearing mice by various plasmid-liposome complexes or by replication-incompetent retrovirus, used alone or complexed to liposomes . In tumor samples from immunodeficient nude mice, moderate levels of gene expression were achieved by liposome-complexed plasmids . Retroviral gene delivery was more effective, and was increased nearly 10-fold by complexing the retrovirus to liposomes . In contrast, in tumor samples from immunocompetent CBA mice treated with the same vectors, no marker gene expression was detected . In immunodeficient mice, tumor growth was not affected by beta-galactosidase gene transfer . However, immunocompetent mice showed a significant decrease in tumor size and increase in survival time after beta-galactosidase delivery . Induction of cytotoxic T cells capable of lysing beta-Gal-transfected tumor cells suggests that tumor cells transduced with the bacterial beta-galactosidase gene may be eliminated in immunocompetent hosts . Our findings also indicate that plasmid-liposome complexes, which achieve a low level of gene expression, and retrovirus-liposome complexes, which result in nearly 100 times higher levels of gene expression in tumor cells in vivo, are similarly effective in inducing an antitumor immune response.

Biochem Biophys Res Commun, 1999 Oct 5, 263(3), 820 - 4
Spectral properties of Trp182, Trp194, and Trp250 on the alpha subunit of bacterial luciferase; Li Z et al.; The phosphorescence and fluorescence properties of bacterial luciferase (alphabeta) mutants from Xenorhabdus luminescens were investigated . All tryptophans in the alpha and beta subunits were replaced with tyrosines except for one or two tryptophans in the alpha subunit . Because one luciferase mutant (W250) retained only a single tryptophan in the alpha subunit while two other mutants (W182/250 and W194/250) each contained two tryptophans in the alpha subunit, it was possible to deduce the spectral properties of these specific tryptophans (Trp182, Trp194, Trp250) . Analyses of the phosphorescence properties were particularly revealing as only a single phosphorescence emission peak at 411-414 nm was observed for the W250 and W194/250 mutants while peaks at 409 and 414 nm could be clearly observed for the W182/250 mutant . Coupled with intrinsic fluorescence quenching experiments, these results show that alphaTrp182 is in a distinctly polar environment while alphaTrp250 is in a hydrophobic region and illustrate the advantages of using phosphorescence to recognize different microenvironments for tryptophan residues .

J Mol Biol, 1999 Oct 8, 292(5), 1003 - 16
High-level expression in Escherichia coli of selenocysteine-containing rat thioredoxin reductase utilizing gene fusions with engineered bacterial-type SECIS elements and co-expression with the selA, selB and selC genes; Arner ES et al.; Mammalian thioredoxin reductase (TrxR) catalyzes reduction of thioredoxin and many other substrates, and is a central enzyme for cell proliferation and thiol redox control . The enzyme is a selenoprotein and can therefore, like all other mammalian selenoproteins, not be directly expressed in Escherichia coli, since selenocysteine-containing proteins are synthesized by a highly species-specific translation machinery . This machinery involves a secondary structure, SECIS element, in the selenoprotein-encoding mRNA, directing selenocysteine insertion at the position of an opal (UGA) codon, normally conferring termination of translation . It is species-specific structural features and positions in the selenoprotein mRNA of the SECIS elements that hitherto have hampered heterologous production of recombinant selenoproteins . We have discovered, however, that rat TrxR can be expressed in E . coli by fusing its open reading frame with the SECIS element of the bacterial selenoprotein formate dehydrogenase H . A variant of the SECIS element designed to encode the conserved carboxyterminal end of the enzyme (-Sec-Gly-COOH) and positioning parts of the SECIS element in the 3'-untranslated region was also functional . This finding revealed that the SECIS element in bacteria does not need to be translated for full function and it enabled expression of enzymatically active mammalian TrxR . The recombinant selenocysteine-containing TrxR was produced at dramatically higher levels than formate dehydrogenase O, the only endogenous selenoprotein expressed in E . coli under the conditions utilized, demonstrating a surprisingly high reserve capacity of the bacterial selenoprotein synthesis machinery under aerobic conditions . Co-expression with the selA, selB and selC genes (encoding selenocysteine synthase, SELB and tRNA(Sec), respectively) further increased the efficiency of the selenoprotein production and thereby also increased the specific activity of the recombinant TrxR to about 25 % of the native enzyme, with as much as 20 mg produced per liter of culture . These results show that with the strategy utilized here, the capacity of selenoprotein synthesis in E . coli is more than sufficient for making possible the use of the bacteria for production of recombinant selenoproteins .

J Arthroplasty, 1999 Sep, 14(6), 677 - 81
Bacterial contamination rates during bone allograft retrieval; Journeaux SF et al.; A retrospective study of allograft bone retrieved from 401 donors between January 1987 and March 1996 was performed to determine the incidence of bacterial contamination . Contamination according to type of donor (live, multiorgan, cadaveric) was also determined . Live donors donating a femoral head demonstrated a contamination rate of 13%; multiorgan donors, 24%; and cadaveric donors, 35% . Donor contamination by type of bone (hemipelvis, femur, tibia) showed no significant difference in the multiorgan donors . In cadaveric donors, there was a significant increase in contamination of the hemipelves as compared to the femur and tibias . Recommendations for contamination control in allograft retrieval are given . Our findings are of great significance for musculoskeletal banks that do not secondarily irradiate and rely on screening of allograft bone for contamination alone.

Curr Opin Chem Biol, 1999 Oct, 3(5), 607 - 13
Structure/function studies on enzymes in the diaminopimelate pathway of bacterial cell wall biosynthesis; Born TL et al.; Within the past 18 months work has continued on the structure and mechanisms of enzymes involved in the diaminopimelic acid/lysine biosynthetic pathway . A novel structure has been determined for a PLP-independent epimerase, and structures with bound substrates have been solved for two other enzymes . Additionally, new studies have appeared describing the chemical mechanisms of three enzymes in the pathway.

Transfusion, 1999 Aug, 39(8), 808 - 17
The cost-effectiveness of autologous transfusion revisited: implications of an increased risk of bacterial infection with allogeneic transfusion; Sonnenberg FA et al.; BACKGROUND: Previous analyses have found autologous transfusion to be very expensive but have not considered avoidance of postoperative bacterial infections as one of its benefits . STUDY DESIGN AND METHODS: A cost-utility analysis using a Markov cohort simulation model compared autologous blood transfusion to allogeneic transfusion in a hypothetical cohort of patients undergoing elective total hip replacement with respect to discounted quality-adjusted life years (QALYs) and health-care system costs . RESULTS: Assuming a base case rate of serious infection of 3.7 percent, a relative risk of infection of 1.85, and additional costs of $12,980 per infection, autologous transfusion has a cost-effectiveness of $2,470 per QALY . If the relative risk of bacterial infection following allogeneic transfusion exceeds 1.1, the cost-effectiveness of autologous transfusion is less than $50,000 per QALY and if the relative risk exceeds 2.4, autologous transfusion is dominant, resulting in both lower costs and greater QALYs . If there were no increased risk of transfusion, the cost-effectiveness of autologous transfusion would be $3,400,000 per QALY . CONCLUSIONS: If there is only a modest increase in the risk of bacterial infection following allogeneic transfusion, autologous transfusion would result in improved outcomes at a cost of less than $50,000 per QALY . Autologous transfusion would be dominant above a relative risk of infection that is within the range of values observed in randomized controlled trials . However, if there is no increased risk of bacterial infection, autologous transfusion would be a very expensive strategy . Until more definitive data are available on the magnitude and costs of this risk, we advise against prematurely closing the debate about the cost-effectiveness of autologous transfusion.

Int J Parasitol, 1999 Jul, 29(7), 1053 - 63
Hypergastrinaemia, abomasal bacterial population densities and pH in sheep infected with Ostertagia circumcincta; Simcock DC et al.; Serum gastrin and pepsinogen concentrations, food intake, abomasal pH and abomasal aerotolerant and anaerobic bacterial populations were measured in sheep infected with Ostertagia circumcincta to search for links between hypergastrinaemia, food intake and changes in the abomasal environment . Abomasal pH and serum gastrin and pepsinogen concentrations were elevated in each of five sheep infected via abomasal cannulae with 150000 exsheathed larval stage three, followed 11 days later by 100000 sheathed larvae given intraruminally . Unparasitised abomasa contained aerotolerant bacterial population densities of between 10(3) and 10(6) cells ml(-1) and these did not change significantly following parasitism . In contrast, anaerobic bacterial population densities increased markedly by about 10(4)-fold following parasitism . Anaerobic numbers changed rapidly when abomasal pH increased from 2.5 to 3.5 . At pH 4 and above, anaerobic bacterial numbers approached levels expected in rumen contents but parameters other than pH did not relate to bacterial numbers . Brief periods when serum gastrin was lower than expected, coinciding with raised abomasal pH, were not explicable by increased bacterial numbers . Food intake, which decreased for a variable period from around Day 5 p.i., correlated poorly with serum gastrin concentration, suggesting hypergastrinaemia is not the sole cause of anorexia in parasitised animals . The survival of substantial numbers of rumen bacteria in the abomasum at only slightly raised pH may significantly lower the bacterial protein available to the sheep.

Adv Microb Physiol, 1999, 41, 291 - 337
The bacterial flagella motor; Berry RM et al.; The bacterial flagellum is probably the most complex organelle found in bacteria . Although the ribosome may be made of slightly more subunits, the bacterial flagellum is a more organized and complex structure . The limited number of flagella must be targeted to the correct place on the cell membrane and a structure with cytoplasmic, cytoplasmic membrane, outer membrane and extracellular components must be assembled . The process of controlled transcription and assembly is still not fully understood . Once assembled, the motor complex in the cytoplasmic membrane rotates, driven by the transmembrane ion gradient, at speeds that can reach many 100 Hz, driving the bacterial cell at several body lengths a second . This coupling of an electrochemical gradient to mechanical rotational work is another fascinating feature of the bacterial motor . A significant percentage of a bacterium's energy may be used in synthesizing the complex structure of the flagellum and driving its rotation . Although patterns of swimming may be random in uniform environments, in the natural environment, where cells are confronted with gradients of metabolites and toxins, motility is used to move bacteria towards their optimum environment for growth and survival . A sensory system therefore controls the switching frequency of the rotating flagellum . This review deals primarily with the structure and operation of the bacterial flagellum . There has been a great deal of research in this area over the past 20 years and only some of this has been included . We apologize in advance if certain areas are covered rather thinly, but hope that interested readers will look at the excellent detailed reviews on those areas cited at those points.

Adv Microb Physiol, 1999, 41, 93 - 137
Bacterial viability and culturability; Barer MR et al.; Renewed interest in the relationships between viability and culturability in bacteria stems from three sources: (1) the recognition that there are many bacteria in the biosphere that have never been propagated or characterized in laboratory culture; (2) the proposal that some readily culturable bacteria may respond to certain stimuli by entering a temporarily non-culturable state termed 'viable but non-culturable' (VBNC) by some authors; and (3) the development of new techniques that facilitate demonstration of activity, integrity and composition of non-culturable bacterial cells . We review the background to these areas of interest emphasizing the view that, in an operational context, the term VBNC is self-contradictory (Kell et al., 1998) and the likely distinctions between temporarily non-culturable bacteria and those that have never been cultured . We consider developments in our knowledge of physiological processes in bacteria that may influence the outcome of a culturability test (injury and recovery, ageing, adaptation and differentiation, substrate-accelerated death and other forms of metabolic self-destruction, prophages, toxin-antitoxin systems and cell-to-cell communication) . Finally, we discuss whether it is appropriate to consider the viability of individual bacteria or whether, in some circumstances, it may be more appropriate to consider viability as a property of a community of bacteria.

Proc Natl Acad Sci U S A, 1999 Sep 28, 96(20), 11346 - 51
Response tuning in bacterial chemotaxis; Jasuja R et al.; Chemotaxis of enteric bacteria in spatial gradients toward a source of chemoattractant is accomplished by increases in the length of swimming runs up the gradient . Biochemical components of the intracellular signal pathway have been identified, but mechanisms for achieving the high response sensitivity remain unknown . Binding of attractant ligand to its receptor inactivates a receptor-associated histidine kinase, CheA, which phosphorylates the signal protein CheY . The reduction in phospho-CheY, CheY-P, levels prolongs swimming runs . Here, the stimulus-response relation has been determined by measurement of excitation responses mediated by the Tar receptor to defined concentration jumps of the attractant, aspartate, administered within milliseconds by photolysis of a photolabile precursor . The bacteria responded to <1% changes in Tar occupancy when adapted to aspartate over concentrations spanning three orders of magnitude . Response amplitudes increased approximately logarithmically with stimulus strength, extending responsiveness over a greater stimulus range . The extent and form of this relation indicates that, in contrast to mechanisms for adaptive recovery, excitation signal generation involves amplification based on cooperative interactions . These interactions could entail inactivation of multiple receptor-CheA signaling complexes and/or simultaneous activation of CheY-P dephosphorylation.

Trends Microbiol, 1999 Oct, 7(10), 420 - 4
Bacterial mechanosensitive channels: integrating physiology, structure and function; Blount P et al.; When confronted with hypo-osmotic stress, many bacterial species are able rapidly to adapt to the increase in cell turgor pressure by jettisoning cytoplasmic solutes into the medium through membrane-tension-gated channels . Physiological studies have confirmed the importance of these channels in osmoregulation . Mutagenesis of one of these channels, combined with structural information derived from X-ray crystallography, has given the first clues of how a mechanosensitive channel senses and responds to membrane tension.

Burns, 1999 Sep, 25(6), 515 - 7
Bacterial endocarditis following a minor burn injury . Case report and review; Paterson P et al.; A case of bacterial endocarditis in a patient with a total burn area of less than 1% is presented . A high index of suspicion for bacterial endocarditis should exist for any burns patient, regardless of burn size, who becomes unwell and has positive blood cultures.

Infect Immun, 1999 Oct, 67(10), 5275 - 81
Differential regulation of macrophage interleukin-1 (IL-1), IL-12, and CD80-CD86 by two bacterial toxins; Foss DL et al.; The ability of innate immune cells to differentially respond to various bacterial components provides a mechanism by which the acquired immune response may be tailored to specific pathogens . The response of innate immune cells to bacterial components provides regulatory signals to cognate immune cells . These signals include secreted cytokines and costimulatory molecules, and to a large extent they determine the quantitative and qualitative nature of the immune response . In order to determine if innate immune cells can differentially respond to bacterial components, we compared the responses of macrophages to two bacterially derived molecules, cholera toxin (CT) and lipopolysaccharide (LPS) . We found that CT and LPS differentially regulated the expression of interleukin-12 (IL-12) and CD80-CD86 but not that of IL-1beta . LPS and CT each induced IL-1beta expression in macrophages, while only LPS induced IL-12 and only CT induced CD80-CD86 . These differences were markedly potentiated in gamma interferon (IFN-gamma)-treated macrophages, in which LPS potently induced IL-12 and CD80-CD86 expression . In contrast, IFN-gamma treatment had no effect on the expression of IL-1beta . These results define a molecular basis for the differential pathogenicities of bacterial toxins and are relevant to the design of vaccine adjuvants able to selectively induce desired types of immunity.

J Leukoc Biol, 1999 Sep, 66(3), 528 - 34
Mechanisms of regulation of the MacMARCKS gene in macrophages by bacterial lipopolysaccharide; Chang S et al.; Bacterial lipopolysaccharide (LPS) stably induced the protein kinase C substrate, MacMARCKS, in murine resident peritoneal macrophages; initial induction of MacMARCKS mRNA was detected within 15 min and was protein synthesis-independent . This response was observed in the macrophage cell line RAW264, and occurred also in response to plasmid DNA, a partial mimetic of other responses to LPS . In murine bone marrow-derived macrophages, MacMARCKS was expressed constitutively due to induction by macrophage colony-stimulating factor . Nuclear run-on transcription revealed that, like tumor necrosis factor alpha (TNF-alpha), MacMARCKS was transcribed constitutively in RAW264 cells . The MacMARCKS promoter was sequenced to -1.7 kb and the transcription start site determined . Transient transfections of RAW264 cells revealed that the 113-bp GC-rich proximal promoter contained all the elements required for both high basal activity and 15- to 20-fold activation by LPS.

Biochem J, 1999 Oct 1, 343 Pt 1, 177 - 83
Bacterial lipolytic enzymes: classification and properties; Arpigny JL et al.; Knowledge of bacterial lipolytic enzymes is increasing at a rapid and exciting rate . To obtain an overview of this industrially very important class of enzymes and their characteristics, we have collected and classified the information available from protein and nucleotide databases . Here we propose an updated and extensive classification of bacterial esterases and lipases based mainly on a comparison of their amino acid sequences and some fundamental biological properties . These new insights result in the identification of eight different families with the largest being further divided into six subfamilies . Moreover, the classification enables us to predict (1) important structural features such as residues forming the catalytic site or the presence of disulphide bonds, (2) types of secretion mechanism and requirement for lipase-specific foldases, and (3) the potential relationship to other enzyme families . This work will therefore contribute to a faster identification and to an easier characterization of novel bacterial lipolytic enzymes.

Biochem Biophys Res Commun, 1999 Sep 24, 263(2), 570 - 4
Bacterial lipopolysaccharide increases prostaglandin production by rat astrocytes via inducible cyclo-oxygenase: evidence for the involvement of nuclear factor kappaB; Pistritto G et al.; This study was set to investigate the mechanisms through which bacterial lipopolysaccharide (LPS) stimulates prostaglandin (PG) production in rat astrocytes . Primary cultures of rat hypothalamic astrocytes were established . Cells were treated with LPS alone or LPS plus antagonists of various pathways, and the subsequent changes in cyclo-oxygenase (COX) activity were monitored by measuring a COX end product, PGE2, released into the incubation medium . It was found that (i) LPS produced a concentration-dependent increase in PGE2 release from astrocytes . The potency of LPS was significantly increased by the addition of serum into the incubation medium; (ii) after 24 h of incubation, inducible COX (COX-2) accounts for most of the LPS-stimulated PG production, as the latter was markedly reduced by dexamethasone and the specific COX-2 inhibitor NS 398; and (iii) nuclear factor kappaB appears to play a role in the activation of COX-2 induced by LPS, since certain inhibitors of this transcription factor were able to antagonize, at least in part, the effects of LPS on PGE2 release .

C R Acad Sci III, 1999 Jul, 322(7), 551 - 6
{Regulation of bacterial proteolytic activity at natural concentrations in dissolved organic matter in a maritime pond}; Crottereau C et al.; The regulation of the bacterial exoproteolytic activity, at natural substrate concentrations, was studied during the survey of an Atlantic coastal marine pond (France) . The regulation of this activity occurs at two different levels: on the one hand, at the cellular level, the ectoenzyme synthesis is regulated by hydrolysis substrates, dissolved combined amino acids (DCAA), and end products, dissolved free amino acids (DFAA), in terms of the relative amounts available to the cell, and on the other hand, at the ecosystem level, i.e . the hydrolytic activity, by the total amounts of DCAA and DFAA in situ . The DFAA acts as an inhibitor in enzymatic synthesis; in contrast, dissolved proteins induce the enzymatic synthesis and the exoproteolytic activity . These results, obtained in natural concentration conditions, confirm the functioning in situ of the ectoenzymatic activity regulation model of Chrost, until now only validated in an enriched experimental medium.

J Clin Microbiol, 1999 Oct, 37(10), 3402 - 4
Elimination of bacterial DNA from Taq DNA polymerases by restriction endonuclease digestion; Carroll NM et al.; The incidence of false positives due to the presence of bacterial DNA in Taq DNA polymerase is an obstacle to the use of PCR in the diagnosis of infection . We describe a method that uses a restriction enzyme to destroy the ability of contaminating sequences to act as templates for a nested PCR which uses primers based on the 16S rRNA genes . The method was used prior to a PCR that amplified 10 fg of bacterial DNA . This method can be readily adapted to suit other sensitive PCRs required for clinical applications.

J Neurol Neurosurg Psychiatry, 1999 Oct, 67(4), 468 - 73
Bacterial meningitis associated with lumbar drains: a retrospective cohort study; Coplin WM et al.; OBJECTIVES: The infective potential of lumbar drainage is an important topic deserving particular study . The aetiology, incidence, and clinical findings associated with bacterial meningitis are described in patients having continuous lumbar CSF drainage to treat communicating hydrocephalus after subarachnoid haemorrhage or CSF leaks after traumatic dural rents . METHODS: Retrospective review of the records of patients with a positive CSF bacterial culture who underwent lumbar drain placement over a 39 month period . RESULTS: Thirteen cases of bacterial meningitis occurred subsequent to the use of 312 lumbar drain kits (4.2%) . All meningitic patients had CSF pleocytosis, but not all had peripheral leukocytosis . Fever, peripheral leukocytosis, and CSF pleocytosis did not help to differentiate the presence of bacterial meningitis from other infections . Eight patients had prior CSF drainage procedures, including ventriculostomy (n=5) or lumbar drain (n=5) placements; two patients received both procedures . Six of 13 patients developed their CSF infection within 24 hours of lumbar drain insertion . Six of 13 patients developed meningitis while receiving antibiotics for other reasons . CONCLUSIONS: External lumbar drainage seems to carry a low risk of infectious meningitis and offers a safe alternative to ventriculostomy or serial lumbar punctures . Antibiotics do not seem to protect completely against developing the infection . The infection happens most often with skin organisms . The meningitis often appears within 24 hours after lumbar drain placement . Daily CSF samples should include bacterial cultures but cell counts may not offer any additional useful information in diagnosing the complication . Lumbar drain insertion and management need not be confined to the intensive care unit.

Mol Gen Genet, 1999 Jul, 261(6), 933 - 40
Expression and biochemical characterisation of recombinant AceA, a bacterial alpha-mannosyltransferase; Geremia RA et al.; Biosynthesis of repeat-unit polysaccharides and N-linked glycans proceeds by sequential transfer of sugars from the appropriate sugar donor to an activated lipid carrier . The transfer of each sugar is catalysed by a specific glycosyltransferase . The molecular basis of the specificity of sugar addition is not yet well understood, mainly because of the difficulty of isolating these proteins . In this study, the aceA gene product expressed by Acetobacter xylinum, which is involved in the biosynthesis of the exopolysaccharide acetan, was overproduced in Escherichia coli and its function was characterised . The aceA ORF was subcloned into the expression vector pET29 in frame with the S.tag epitope . The recombinant protein was identified, and culture conditions were optimised for production of the soluble protein . The results of test reactions showed that AceA is able to transfer one alpha-mannose residue from GDP-mannose to cellobiose-P-P-lipid to produce alpha-mannose-cellobiose-P-P-lipid . AceA was not able to use free cellobiose as a substrate, indicating that the pyrophosphate-lipid moiety is needed for enzymatic activity.

Biochim Biophys Acta, 1999 Aug 4, 1412(3), 273 - 81
Determination of Q(A)-content in bacterial reaction centers: an indispensable requirement for quantifying B-branch charge separation
Ogrodnik A, Muller P, Hartwich G, Michel-Beyerle ME.
We have been able to determine the occupancy of the quinone site at the A-branch (Q(A)) of a reaction center preparation with an accuracy of 2% . This is achieved by accumulating the P(+)Q(-)(A) state after multiple actinic excitation and monitoring the extent of the 30 ms ground state bleaching . This bleaching is corrected for deviations from complete saturation due to competing charge separation to the B-branch . On the other hand, knowledge of the Q(A) content is indispensable for determining the yield of B-branch charge separation from nanosecond transients associated with the recombination of P(+)H(-)(B), which have to be corrected for the nanosecond signal originating from P(+)H(-)(A) of RCs having lost Q(A).

Lupus, 1999, 8(6), 449 - 55
Induction of antiphospholipid antibodies by immunization with synthetic viral and bacterial peptides; Gharavi EE et al.; We previously induced pathogenic antibodies against anionic phospholipids (PL) in experimental animals by immunization with lipid-free purified human beta2glycoprotein I (beta2GPI) . We hypothesized that antiphospholipid antibodies (aPL) are induced by in vivo binding of foreign beta2GPI to self-PL, thus forming an immunogenic complex against which aPL antibodies are produced . If this hypothesis is true, other PL-binding proteins that are products of ubiquitous viral/bacterial agents may also induce aPL . To test this hypothesis, groups of NIH/Swiss mice were immunized with synthetic peptides of viral and bacterial origin that share structural similarity with the putative PL-binding region of beta2GPI . Compared with the control groups, animals immunized with the peptides produced significantly higher levels of aPL and anti-beta2GPI antibodies . These findings demonstrate that some PL-binding viral and bacterial proteins function like beta2GPI in inducing aPL and anti-beta2GPI production, and are consistent with a role for such viral and bacterial proteins in inducing aPL antibody production in humans.

J Virol, 1999 Oct, 73(10), 8320 - 9
Cloning of the human cytomegalovirus (HCMV) genome as an infectious bacterial artificial chromosome in Escherichia coli: a new approach for construction of HCMV mutants; Borst EM et al.; We have recently introduced a novel procedure for the construction of herpesvirus mutants that is based on the cloning and mutagenesis of herpesvirus genomes as infectious bacterial artificial chromosomes (BACs) in Escherichia coli (M . Messerle, I . Crnkovic, W . Hammerschmidt, H . Ziegler, and U . H . Koszinowski, Proc . Natl . Acad . Sci . USA 94:14759-14763, 1997) . Here we describe the application of this technique to the human cytomegalovirus (HCMV) strain AD169 . Since it was not clear whether the terminal and internal repeat sequences of the HCMV genome would give rise to recombination, the stability of the cloned HCMV genome was examined during propagation in E . coli, during mutagenesis, and after transfection in permissive fibroblasts . Interestingly, the HCMV BACs were frozen in defined conformations in E . coli . The transfection of the HCMV BACs into human fibroblasts resulted in the reconstitution of infectious virus and isomerization of the reconstituted genomes . The power of the BAC mutagenesis procedure was exemplarily demonstrated by the disruption of the gpUL37 open reading frame . The transfection of the mutated BAC led to plaque formation, indicating that the gpUL37 gene product is dispensable for growth of HCMV in fibroblasts . The new procedure will considerably speed up the construction of HCMV mutants and facilitate genetic analysis of HCMV functions.

Immunol Lett, 1999 Aug 3, 69(2), 233 - 8
Bacterial lipopolysaccharide induced B cell activation is mediated via a phosphatidylinositol 3-kinase dependent signaling pathway; Venkataraman C et al.; Bacterial lipopolysaccharide (LPS) is a potent stimulant of B cells and macrophages . LPS induces B cell proliferation and differentiation into antibody secreting cells . In addition, LPS also stimulates IL-6 secretion in mature B cells and in immature B cell lines such as WEHI-231 . Although sufficient literature is available on LPS induced signaling events in monocytes and macrophages, the mechanisms involved in LPS induced B cell activation are not well understood . In this report, it is shown that both LPS mediated B cell proliferation and IL-6 secretion are dependent on phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathways . The B cell specific co-receptor, CD19 is not tyrosine phosphorylated in LPS stimulated B cells . Thus, in contrast to B cell antigen receptor (BCR) signaling, the activation of PI 3-kinase appears not to be related to the recruitment of PI 3-kinase to tyrosine phosphorylated CD19 . This is the first demonstration of the importance of PI 3-kinase signaling pathway in LPS mediated B lymphocyte activation.

FEMS Microbiol Lett, 1999 Oct 1, 179(1), 1 - 9
Regulation of bacterial photosynthesis genes by oxygen and light; Gregor J et al.; Most bacteria have the capability to adapt to changes in their environment . Facultatively phototrophic bacteria like Rhodobacter can switch from aerobic respiration to anoxygenic photosynthesis in the absence of oxygen . The formation of the photosynthetic apparatus is primarily regulated by oxygen tension . The amount of photosynthetic complexes is influenced by the light intensity in anaerobic cultures . This review focuses on the molecular mechanisms involved in the regulation of Rhodobacter photosynthesis genes by oxygen and light.

Microbiol Immunol, 1999, 43(6), 543 - 50
Detection and nucleotide sequence analysis of human caliciviruses (HuCVs) from samples in non-bacterial gastroenteritis outbreaks in Hokkaido, Japan; Ohyama T et al.; Samples of feces and vomit collected from patients during 13 non-bacterial gastroenteritis outbreaks which occurred in Hokkaido between 1995 and 1998 were examined by electron microscopy (EM) and reverse-transcription polymerase chain reaction (RT-PCR) for evidence of infection with human caliciviruses (HuCVs) . In 6 food-borne outbreaks, oysters were the probable source of infection, while the origin of HuCVs was not found out for the other 7 outbreaks . One-hundred-eleven of 214 stool, vomit and oyster specimens examined gave positive results by RT-PCR, while HuCVs were detected by EM in 36 of 121 stool specimens examined . We determined the nucleotide sequences of 470-bp or 373-bp PCR products amplified from the RNA polymerase region of the HuCV genomes with primer sets MR3/4 and Yuri22F/R, respectively . The sequences of different strains revealed great heterogenicity, with a range of 60 to 100% homology among strains . In a few cases, a mixed genotype was found in the same patient or same outbreak by means of nested PCR and cloning of PCR products into an appropriate vector . Of the 19 different strains found, 4 strains could be classified as Norwalk virus (genogroup 1) and the other 15 strains as Snow Mountain agent (genogroup 2) based on genotyping with homology analysis . Furthermore, the strains belonging to genogroup 2 could be classified into 4 subgroups with more than 93% homology in amino acids among strains in the subgroup.

Otolaryngol Clin North Am, 1999 Oct, 32(5), 793 - 811
Acute viral and bacterial infections of the salivary glands; McQuone SJ; Acute infection can involve any salivary gland, but it predominately affects the major salivary glands, especially the parotid gland . The anatomic and physiologic factors accounting for the parotid gland's predilection for infection are reviewed . Numerous conditions that are predisposed to acute bacterial sialadenitis and differ from risk factors associated with viral infection are also reviewed . The pathogenesis, diagnostic evaluation, treatment, complications, and prognosis of bacterial infections are discussed and contrasted with those of viral infections.

Eur Cytokine Netw, 1999 Sep, 10(3), 373 - 82
Impairment of HIV polymorphonuclear leukocyte transmigration across T84 cell monolayers: an alternative mechanisms for increased intestinal bacterial infections in AIDS?
Hofman P, Fischer F, Far DF, Selva E, Battaglione V, Bayle J, Rossi B.
Our objective was to study the influence of HIV infection of polymorphonuclear leukocytes (PMN) on transepithelial migration . To date, reports of functional PMN chemotaxis in AIDS are contradictory . This is the first attempt to assess this function via an in vitro model allowing transmigration of neutrophils through an intestinal epithelial barrier . PMN were isolated from 45 HIV-infected patients and 45 healthy volunteers . PMN transmigration across T84 epithelial cells was initiated by applying either various concentrations of formyl-met-leu-phe peptide (f-MLP) or interleukin-8 and assayed by quantification of myeloperoxidase activity . CD11b, CD18, and CD47 expression on PMN was compared before and after transepithelial migration by flow cytometry analysis . CD11b expression was studied by electron microscopy . Apoptosis of transmigrated HIV PMN and control PMN was investigated by morphology and DNA fragmentation characterization . Compared to control PMN, HIV PMN exhibited a decrease in transepithelial migration that directly correlated with CD4+ counts . Basal and transepithelial migration-mediated expression of CD11b, CD18, and CD47 were unmodified in HIV PMN compared to control PMN . Electron microscopy labeling confirmed no difference in CD11b expression on HIV and control PMN . The index of apoptosis in transmigrated HIV PMN and control PMN was identical . These data provide evidence of a defect in the f-MLP-induced chemotaxis of PMN from HIV-infected patients across an intestinal epithelial barrier . This defective migration is not due to a quantitative modification of CD11b, CD18 and CD47 on HIV PMN suggesting a more subtle alteration . The impairment in the transmigration function may contribute in vivo to an increased susceptibility to intestinal bacterial infection in HIV-infected patients.

Appl Environ Microbiol, 1999 Sep, 65(9), 3982 - 9
High bacterial diversity in permanently cold marine sediments; Ravenschlag K et al.; A 16S ribosomal DNA (rDNA) clone library from permanently cold marine sediments was established . Screening 353 clones by dot blot hybridization with group-specific oligonucleotide probes suggested a predominance of sequences related to bacteria of the sulfur cycle (43.4% potential sulfate reducers) . Within this fraction, the major cluster (19.0%) was affiliated with Desulfotalea sp . and other closely related psychrophilic sulfate reducers isolated from the same habitat . The cloned sequences showed between 93 and 100% similarity to these bacteria . Two additional groups were frequently encountered: 13% of the clones were related to Desulfuromonas palmitatis, and a second group was affiliated with Myxobacteria spp . and Bdellovibrio spp . Many clones (18.1%) belonged to the gamma subclass of the class Proteobacteria and were closest to symbiotic or free-living sulfur oxidizers . Probe target groups were further characterized by amplified rDNA restriction analysis to determine diversity within the groups and within the clone library . Rarefaction analysis suggested that the total diversity assessed by 16S rDNA analysis was very high in these permanently cold sediments and was only partially revealed by screening of 353 clones.

Appl Environ Microbiol, 1999 Sep, 65(9), 3834 - 42
Spatial heterogeneity of bacterial populations along an environmental gradient at a shallow submarine hydrothermal vent near Milos Island (Greece); Sievert SM et al.; The spatial heterogeneity of bacterial populations at a shallow-water hydrothermal vent in the Aegean Sea close to the island of Milos (Greece) was examined at two different times by using acridine orange staining for total cell counts, cultivation-based techniques, and denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene fragments . Concurrent with measurements of geochemical parameters, samples were taken along a transect from the center of the vent to the surrounding area . Most-probable-number (MPN) counts of metabolically defined subpopulations generally constituted a minor fraction of the total cell counts; both counting procedures revealed the highest cell numbers in a transition zone from the strongly hydrothermally influenced sediments to normal sedimentary conditions . Total cell counts ranged from 3.2 x 10(5) cells ml(-1) in the water overlying the sediments to 6.4 x 10(8) cells g (wet weight) of sediment(-1) . MPN counts of chemolithoautotrophic sulfur-oxidizing bacteria varied between undetectable and 1.4 x 10(6) cells g(-1) . MPN counts for sulfate-reducing bacteria and dissimilatory iron-reducing bacteria ranged from 8 to 1.4 x 10(5) cells g(-1) and from undetectable to 1.4 x 10(6) cells g(-1), respectively . DGGE revealed a trend from a diverse range of bacterial populations which were present in approximately equal abundance in the transition zone to a community dominated by few populations close to the center of the vent . Temperature was found to be an important parameter in determining this trend . However, at one sampling time this trend was not discernible, possibly due to storm-induced disturbance of the upper sediment layers.

AJNR Am J Neuroradiol, 1999 Aug, 20(7), 1359 - 64
Sonographic nomogram of the leptomeninges (pia-glial plate) and its usefulness for evaluating bacterial meningitis in infants; Jequier S et al.; BACKGROUND AND PURPOSE: To our knowledge, the upper limits of the thickness of normal meninges on neurosonograms are not known . We therefore established a nomogram for sonographic measurements of the leptomeninges (pia-glial plate) and assessed its usefulness in neurosonographic examinations of children with bacterial meningitis . METHODS: The pia mater-cortical glia limitans complex on the surface of the brain and in the sulcus of a frontal gyrus was measured on neurosonograms in 100 infants without meningeal disease in order to establish a nomogram of the thickness of this pia-glial plate, referred to as the leptomeninx . Effects of prematurity, age, sex, and single-layer (surface) versus double-layer (sulcus) measurements were analyzed . Meningeal thicknesses derived from a retrospective analysis of the neurosonograms of 33 patients with purulent meningitis and a prospective study of 22 patients with bacterial meningitis were compared with the nomograms . Clinical outcomes of children with meningeal thickening were compared with those of affected children with normal meninges . RESULTS: The distribution of sulci measurements was significantly asymmetrical around the mean . Statistical data showed no influence of prematurity and sex, but showed surface measurements to be more consistent than sulcal measurements . Older chronological age was related to slightly larger sulci, but did not influence the surface measurements . In children with bacterial meningitis, the surface meninges were less frequently thickened than were the sulci . Sulcal enlargement occurred often in combination with echogenic deposits in the sub-arachnoid space . CONCLUSION: Leptomeninges are best measured on the surface of a gyrus rather than in a sulcus, as the normal thickness of the sulci shows much more variability . Clinical outcome of bacterial meningitis cannot be predicted by presence or absence of meningeal thickening as the only sonographic abnormality.

Infect Dis Clin North Am, 1999 Sep, 13(3), 647 - 59, viii
Supportive management in bacterial meningitis; Rauf SJ et al.; The central nervous system and systemic complications of bacterial meningitis cause significant morbidity and mortality . This article offers insight into the clinical features, pathogenesis, and management of these complications . In many instances, the improved outcome of intervention is based on clinical suspicion and early recognition . The management of complications is evolving and is presently based mainly on supportive care.

Infect Dis Clin North Am, 1999 Sep, 13(3), 711 - 33, viii
Bacterial meningitis and the newborn infant; Pong A et al.; Bacterial meningitis in the neonate differs from meningitis in the older infant and child in a number of ways . Bacterial pathogens primarily are associated with the maternal genitourinary tract . Symptoms and physical findings may be nonspecific, and a high index of suspicion is needed . Management may vary depending on the maturity of the infant and the bacterial pathogen that is isolated.

Infect Dis Clin North Am, 1999 Sep, 13(3), 579 - 94, vi-vii
Clinical presentations, diagnosis, and prognostic factors of bacterial meningitis; Kaplan SL; The clinical presentations of children and adults with bacterial meningitis have not changed over the past several decades, and a high index of suspicion remains critical for timely identification of infected patients . With the virtual disappearance of H . influenzae type B meningitis (Hib) in areas of the world where Hib conjugate vaccine is administered routinely, the utility of commercially available tests for rapid detection of bacterial polysaccharides has diminished . Detection of gene products of meningeal pathogens in cerebrospinal fluid or blood is still experimental . The prognostic findings of recent studies are not different from those previously described, despite advances in the supportive care of critically ill patients.

Infect Dis Clin North Am, 1999 Sep, 13(3), 527 - 48, v-vi
Pathogenesis of bacterial meningitis; Leib SL et al.; Bacterial meningitis is fatal in 5% to 40% of patients and causes neurologic sequelae in up to 30% of survivors . Much has been learned recently about the mechanisms that lead to brain injury during meningitis . Once bacteria have gained access to the central nervous system, their multiplication triggers a complex host response consisting of humoral and cellular immune mediators, reactive oxygen intermediates, matrix-metalloproteinases, and other host-derived factors . Alterations of the cerebral vasculature, with disruption of the blood brain barrier and global and focal ischemia, ultimately lead to functional and structural brain damage . This article reviews current concepts of the pathophysiology of bacterial meningitis and emphasizes possible therapeutic strategies to prevent its harmful consequences.

J Control Release, 1999 Aug 27, 61(1-2), 51 - 63
Bacterial ghosts as drug carrier and targeting vehicles; Huter V et al.; A novel system for the packaging of drugs as well as vaccines is presented . Bacterial ghosts are intact, non-denatured bacterial envelopes that are created by lysis of bacteria through the expression of cloned phage PhiX174 gene E . Inhibition of induced E-mediated lysis by MgSO(4), harvesting of cells by centrifugation, and resuspension in low-ionic-strength buffers leads to rapid, violent lysis and results in empty bacterial envelopes with large (approximately 1 microm in diameter) openings . The construction of plasmid pAV1, which encodes a streptavidin fusion protein with an N-terminal membrane anchor sequence, allows the loading of the inner side of the cytoplasmic membrane with streptavidin . The functionality and efficacy of binding of even large biotinylated compounds in such streptavidin ghosts (SA-ghosts) was assessed using the enzyme alkaline phosphatase . The successful binding of biotinylated fluorescent dextran, as well as fluorescent DNA complexed with biotinylated polylysine, was demonstrated microscopically . The display by bacterial ghosts of morphological and antigenic surface structures of their living counterparts permits their attachment to target tissues such as the mucosal surfaces of the gastrointestinal and respiratory tract, and their uptake by phagocytes and M cells . In consequence, SA-ghosts are proposed as drug carriers for site-specific drug delivery.

Proc Natl Acad Sci U S A, 1999 Aug 31, 96(18), 10344 - 8
Bacterial inactivation by using near- and supercritical carbon dioxide; Dillow AK et al.; The three most common methods of sterilization in use today are ethylene oxide exposure, gamma-irradiation, and steam sterilization . Each of these methods has serious limitations for the sterilization of some materials used in medicine, especially thermally and hydrolytically sensitive polymers by themselves and in combination with proteins . In this work, we demonstrate a potential new method of sterilization by using supercritical fluid carbon dioxide . Using this method we achieve complete inactivation of a wide variety of bacterial organisms at moderate temperatures and in the absence of organic solvents or irradiation . Sterilization is a function of both the proximity to the fluid's critical point and the chemical nature of the fluid itself . When biodegradable polymers poly(lactic-co-glycolic) acid and polylactic acid were included in the sterilization process, there was no effect on the inactivation efficiency, yet no physical or chemical damage to these thermally and hydrolytically labile materials was observed.

J Infect, 1999 Jul, 39(1), 55 - 60
Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis; Ohga S et al.; OBJECTIVES: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 beta and tumor necrosis factor (TNF) alpha were measured to assess the effect and application of dexamethasone (Dex) therapy for bacterial meningitis . METHODS: associations between clinical findings and CSF parameters were first investigated, and prognosis was compared between 25 patients with Dex and 12 without Dex therapy . RESULTS: patients with the presence of disturbed consciousness showed higher CSF levels of TNF alpha (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P < 0.O5) . Simultaneous increase of TNF alpha (> 1000 pg/ml) and protein (> 100 g/dl) was observed in 80%, of patients with profoundly disturbed consciousness . Patients with Dex therapy presented higher TNF alpha/protein levels at diagnosis than those without Dex therapy (P < 0.05) . Despite worse conditions at diagnosis, only one of 14 Dex-treated patients whose initial CSF TNF alpha levels exceeded 1000 pg/ml developed deafness . On the other hand, two of four patients without Dex therapy who had the same TNF alpha level suffered from psychomotor retardation . The differences in the frequency of sequelae between those with and without Dex therapy were significant in patients showing high TNF alpha level (P < O.05), but not in those showing high CSF levels of IL-1 beta or protein . The logistic regression analysis indicated that high CSF protein level (P < O.0001), or no Dex therapy (P=0.0001) was the independent risk factor for sequelae . CONCLUSIONS: although the study number was small, our observations suggested that CSF TNF alpha/protein levels reflected the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF alpha levels.

Biotechnol Appl Biochem, 1999 Aug, 30 ( Pt 1), 59 - 64
Expression and purification of a secreted functional mouse/human chimaeric antibody against bacterial endotoxin in baculovirus-infected insect cells; Tan W et al.; We have created a mouse/human chimaeric antibody by taking antigen-binding fragment (Fab) genes of a mouse antibody-producing hybridoma with specificity for bacterial endotoxin and joining them to human Ig crystallizing-fragment (Fc) genes using recombinant DNA techniques . This chimaeric antibody has been expressed in Sf21 and High Fivetrade mark (BTI-TN-5B1-4) insect cells using the baculovirus expression system, which may allow the mass production of secretory recombinant antibodies . This was achieved by using infection with a double-recombinant virus containing cDNAs of both the Ig heavy-chain (HC) and light-chain (LC) genes . Prior to recombination, each gene was cloned into the dual-expression baculovirus transfer vector pPLSP2, which permitted the insertion of the LC gene in-frame with the signal peptide of honey bee melittin downstream of the polyhedrin promoter, and of the HC gene in-frame with the signal peptide of Bombyx mori larval serum protein downstream of the p10 promoter . Our results showed that the polypeptide chains were secreted by insect cells and correctly assembled into H(2)L(2) heterodimers containing N-linked carbohydrate at the heavy chain . Furthermore, the recombinant chimaeric antibody exhibited a similar antigen specificity to that of the monoclonal antibody . More importantly, it provides a generic method for the high-level expression of antibodies.

Genes Dev, 1999 Aug 15, 13(16), 2134 - 47
Bacterial promoter architecture: subsite structure of UP elements and interactions with the carboxy-terminal domain of the RNA polymerase alpha subunit; Estrem ST et al.; We demonstrate here that the previously described bacterial promoter upstream element (UP element) consists of two distinct subsites, each of which, by itself, can bind the RNA polymerase holoenzyme alpha subunit carboxy-terminal domain (RNAP alphaCTD) and stimulate transcription . Using binding-site-selection experiments, we identify the consensus sequence for each subsite . The selected proximal subsites (positions -46 to -38; consensus 5'-AAAAAARNR-3') stimulate transcription up to 170-fold, and the selected distal subsites (positions -57 to -47; consensus 5'-AWWWWWTTTTT-3') stimulate transcription up to 16-fold . RNAP has subunit composition alpha(2)betabeta'sigma and thus contains two copies of alphaCTD . Experiments with RNAP derivatives containing only one copy of alphaCTD indicate, in contrast to a previous report, that the two alphaCTDs function interchangeably with respect to UP element recognition . Furthermore, function of the consensus proximal subsite requires only one copy of alphaCTD, whereas function of the consensus distal subsite requires both copies of alphaCTD . We propose that each subsite constitutes a binding site for a copy of alphaCTD, and that binding of an alphaCTD to the proximal subsite region (through specific interactions with a consensus proximal subsite or through nonspecific interactions with a nonconsensus proximal subsite) is a prerequisite for binding of the other alphaCTD to the distal subsite.

Clin Ther, 1999 Jul, 21(7), 1158 - 70
Comparison of cefuroxime axetil and amoxicillin/clavulanate in the treatment of acute bacterial sinusitis; Henry DC et al.; This double-masked, multicenter, randomized clinical trial compared the efficacy and tolerability of cefuroxime axetil and amoxicillin/clavulanate in the treatment of acute bacterial maxillary sinusitis . A total of 263 patients with acute bacterial maxillary sinusitis were randomly assigned to receive 10 days of treatment with either cefuroxime axetil 250 mg twice daily (n = 132) or amoxicillin/clavulanate 500/125 mg 3 times daily (n = 131) . Patients' responses to treatment were assessed once during treatment (6 to 8 days after the start of treatment), at the end of treatment (1 to 3 days posttreatment), and at follow-up (26 to 30 days after cessation of treatment) . Clinical success, defined as cure or improvement, was equivalent in the cefuroxime axetil and amoxicillin/ clavulanate groups at the end-of-treatment and follow-up assessments . Patients in both groups showed improvements in symptoms of acute sinusitis at the during-treatment visit . Treatment with amoxicillin/clavulanate was associated with a significantly higher incidence of drug-related adverse events than treatment with cefuroxime axetil (29% vs 17%), primarily reflecting a higher incidence of gastrointestinal adverse events (23% vs 11%), particularly diarrhea . Two patients in the cefuroxime axetil group and 8 patients in the amoxicillin/clavulanate group withdrew from the study due to adverse events (P = 0.06) . These results indicate that cefuroxime axetil 250 mg twice daily is as effective as amoxicillin/clavulanate 500 mg 3 times daily in the treatment of acute sinusitis and produces fewer gastrointestinal adverse events . cefuroxime axetil, amoxicillin/clavulanate, acute sinusitis.

Pediatr Infect Dis J, 1999 Aug, 18(8), 666 - 71
Comparison of procalcitonin with interleukin 8, C-reactive protein and differential white blood cell count for the early diagnosis of bacterial infections in newborn infants; Franz AR et al.; OBJECTIVE: To evaluate procalcitonin (PCT) as a test for early diagnosis of bacterial infections (BI) in newborn infants and to compare the results of PCT with those of interleukin 8 (IL-8), C-reactive protein (CRP) and differential white blood cell count . STUDY DESIGN: PCT was prospectively measured along with IL-8, CRP and differential white blood cell counts and blood cultures in 197 newborn infants at the first suspicion of bacterial infection . PCT, IL-8, CRP and differential white blood cell counts were analyzed for sensitivity, specificity and positive and negative predictive values after receiver operating characteristic curve analysis for best thresholds . The kinetics of PCT was determined in infants with and without BI . RESULTS: Forty-six infants were diagnosed clinically as having BI, of whom 9 had BI with positive blood cultures . At a cutoff value of 0.50 microg/l, PCT detected combined culture-proved and clinical BI with a sensitivity of 57% (95% confidence interval, 41%, 71%) and a specificity of 66% (95% confidence interval, 57%, 74%) . The combination of IL-8 > or =70 ng/l and/or CRP >10 mg/l achieved a sensitivity of 91% (95% confidence interval, 79%, 98%) and a specificity of 73% (95% confidence interval, 64%, 81%) . PCT values of infected and not infected infants tended to rise for 24 h after initial evaluation and then decreased . CONCLUSION: The combination of IL-8 and CRP is more reliable than PCT as a test for early diagnosis of BI in newborn infants.

Drug Metab Dispos, 1999 Sep, 27(9), 999 - 1004
Enhancement of cytochrome P-450 3A4 catalytic activities by cytochrome b(5) in bacterial membranes; Yamazaki H et al.; Activities of testosterone, nifedipine, and midazolam oxidation by recombinant cytochrome P-450 (P-450) 3A4 coexpressed with human NADPH-P-450 reductase (NPR) in bacterial membranes (CYP3A4/NPR membranes) were determined in comparison with those of other recombinant systems and of human liver microsomes with high contents of CYP3A4 . Growth conditions for Escherichia coli transformed with the bicistronic construct affected expression levels of CYP3A4 and NPR; an excess of NPR over P-450 in membrane preparations enhanced CYP3A4-dependent testosterone 6beta-hydroxylation activities of the CYP3A4/NPR membranes . Cytochrome b(5) (b(5)) and apolipoprotein b(5) further enhanced the testosterone 6beta-hydroxylation activities of CYP3A4/NPR membranes after addition to either bacterial membranes or purified enzymes . NPR was observed to enhance catalytic activity when added to the CYP3A4/NPR membranes, either in the form of bacterial membranes or as purified NPR (in combination with cholate and b(5)) . Apparent maximal activities of testosterone 6beta-hydroxylation in CYP3A4/NPR membranes were obtained when the molar ratio of CYP3A4/NPR/b(5) was adjusted to 1:2:1 by mixing membranes containing each protein . Testosterone 6beta-hydroxylation, nifedipine oxidation, and midazolam 4- and 1'-hydroxylation activities in CYP3A4/NPR membranes plus b(5) systems were similar to those measured with microsomes of insect cells coexpressing CYP3A4 with NPR and/or of human liver microsomes, based on equivalent CYP3A4 contents . These results suggest that CYP3A4/NPR membrane systems containing b(5) are very useful models for prediction of the rates for liver microsomal CYP3A4-dependent drug oxidations.

Br J Ophthalmol, 1999 Sep, 83(9), 1050 - 5
Intravitreal dexamethasone in exogenous bacterial endophthalmitis: results of a prospective randomised study; Das T et al.; AIM: To evaluate the efficacy of intravitreal dexamethasone co-administered with intravitreal antibiotics along with vitrectomy in the management of exogenous bacterial endophthalmitis . METHODS: In a prospective randomised clinical trial, 63 patients (63 eyes) with suspected bacterial endophthalmitis (postoperative and post-traumatic) were treated with vitrectomy and intravitreal antibiotics and randomised to intravitreal dexamethasone (IOAB with = 29 eyes) and no dexamethasone (IOAB without = 34 eyes) . Inflammation score (IS) and visual acuity were measured by two masked observers before surgery, and at 1, 4, and 12 weeks after surgery in both the groups . RESULTS: There was significant reduction (p <0.0001) in IS at 1, 4, and 12 weeks after the surgery in the "IOAB with" group; there was temporary but significant increase (p <0.01) in IS at 1 week in the "IOAB without" group, before decline (p <0.001) of IS at 4 and 12 weeks . The magnitude and relative percentage change in IS between the two groups were found to be significant at 1 (p <0.0001), and 4 (p <0.01) weeks, and not at 12 weeks . The visual acuity at 12 weeks was comparable in both the IOAB with and IOAB without groups . CONCLUSION: Intravitreal dexamethasone helps in early reduction of inflammation in exogenous bacterial endophthalmitis, but has no independent influence on the visual outcome . In selected patients with endophthalmitis where oral corticosteroids cannot be given for medical reasons intravitreal corticosteroids could be beneficial; in other situations they could be complementary to oral corticosteroid therapy.

Br J Surg, 1999 Aug, 86(8), 1020 - 4
Bacterial infection and extent of necrosis are determinants of organ failure in patients with acute necrotizing pancreatitis; Isenmann R et al.; BACKGROUND: The risk factors predisposing to organ failure in patients with necrotizing pancreatitis remain unclear . The relationship between the extent of pancreatic necrosis, the presence of infection and the incidence of organ failure was analysed . METHODS: In a retrospective review, the occurrence of pulmonary insufficiency, renal insufficiency, shock, sepsis/sepsis-like syndrome (SLS) and coagulopathy was evaluated in 273 patients with necrotizing pancreatitis, and a comparison was made between patients with sterile or infected necrosis . Additionally, the relation between the incidence of organ failure and extent of pancreatic parenchymal necrosis was investigated by classifying the patients into three groups according to the amount of necrotic tissue found by contrast-enhanced computed tomography (group 1, extent less than 30 per cent; group 2, 30-50 per cent; group 3, more than 50 per cent) . RESULTS: Organ failure was more frequent in patients with infected necrosis than in those with sterile necrosis . Differences were found in the incidence of pulmonary insufficiency, sepsis/SLS and coagulopathy . Organ failure occurred more frequently in group 3 than in group 2 or 1 (95 versus 79 and 66 per cent; P = 0.0004) . The extent of infected necrosis was not related to the incidence of organ failure (group 1, 88 per cent; group 2, 86 per cent; group 3, 96 per cent) . However, there was a relation between the incidence of organ failure and the extent of sterile necrosis (group 1, 59 per cent; group 2, 74 per cent; group 3, 94 per cent; P = 0.0001) . Multivariate analysis confirmed the presence of infection and the extent of necrosis as independent determinants of organ failure . CONCLUSION: The incidence of organ failure is determined by both bacterial infection and extent of necrosis . The incidence of organ failure is determined by the extent of necrotic parenchyma in patients with sterile necrosis . Infected necrosis is associated with a high incidence of organ failure irrespective of the extent of necrosis.

Surgery, 1999 Aug, 126(2), 349 - 57
Discordant tumor necrosis factor-alpha superfamily gene expression in bacterial peritonitis and endotoxemic shock; Tannahill CL et al.; BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is a member of a large family of predominantly homotrimeric type II membrane-associated proteins with both proinflammatory and apoptosis-inducing properties . Although TNF-alpha expression has been studied extensively, little is known about the expression of other members of the TNF-alpha superfamily during acute inflammatory processes . METHODS: TNF-alpha, Fas ligand (FasL), and TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) messenger RNA (mRNA) expression were examined in liver, lung, spleen, and kidney after either a cecal ligation and puncture or endotoxemic shock with use of semiquantitative reverse transcriptase-polymerase chain reaction . RESULTS: Cecal ligation and puncture increased TNF-alpha mRNA in lung and liver (both P < .05) within 3 hours, which was paralleled by increased FasL mRNA . In the spleen TNF-alpha and FasL mRNA significantly declined (both P < .05) . In contrast to TNF-alpha and FasL, TRAIL mRNA levels were unchanged in all organs except lung, where it was reduced at 24 hours (P < .05) . Endotoxemic shock also increased lung TNF-alpha and FasL mRNA levels (both P < .05) . CONCLUSIONS: In acute inflammatory processes TNF-alpha and FasL mRNA increase concordantly in several solid organs . In contrast, TRAIL mRNA levels do not consistently change during these acute inflammatory processes, suggesting that its expression is under independent and discordant regulatory control.

Arch Pathol Lab Med, 1999 Sep, 123(9), 778 - 81
Endoscopic biopsy pathology of Helicobacter pylori gastritis . Comparison of bacterial detection by immunohistochemistry and Genta stain; Toulaymat M et al.; OBJECTIVES: To describe the endoscopic biopsy pathology of Helicobacter pylori gastritis, compare bacterial detection by immunohistochemistry using a specific antibody with the Genta stain, and to compare the relative costs of the 2 techniques . DESIGN: One hundred cases of gastritis identified as positive for H pylori by Genta stain and 100 cases considered negative by the same technique were stained using an anti-H pylori-specific polyclonal antibody . Laboratory reagent and labor costs for the 2 methods were compared . RESULTS: Chronic active gastritis with lymphoid follicles was significantly associated with H pylori infection (P <.0001) . The immunohistochemical method had a sensitivity of 97% and a specificity of 98% compared with the Genta stain, with strong agreement for grading density of organisms (kappa = 0.85; P <.001) . Reagent costs were similar for both methods, but immunohistochemistry using an autoimmunostainer required less dedicated technical time and hence was less expensive than the Genta stain . CONCLUSIONS: Immunohistochemistry using a specific antibody is an accurate and cost-effective method for H pylori detection in gastric biopsies.

Sex Transm Dis, 1999 Aug, 26(7), 404 - 9
Bacterial vaginosis, ethnicity, and the use of genital cleaning agents: a case control study; Rajamanoharan S et al.; BACKGROUND AND OBJECTIVES: Bacterial vaginosis and vaginal douching are both reported to be more common in African-American and Caribbean than white women . It is also thought that douching alters the vaginal milieu . This study was conducted to examine associations between genital cleaning practices, bacterial vaginosis, and ethnic group . STUDY DESIGN: Case-control study of 100 women with bacterial vaginosis, diagnosed by Nugent's criteria, and 100 women without bacterial vaginosis attending a sexually transmitted diseases clinic in an ethnically heterogeneous inner-city area in London, England . RESULTS: Bacterial vaginosis was more common among black Caribbean than white women (OR, 2.1; 95% CI, 1.1-4.1) . Vulval use of bubble bath or antiseptic solutions and douching with proprietary or homemade solutions were significantly more common in women with bacterial vaginosis than without . After controlling for use of vulval and vaginal antiseptics and bubble bath, douching, and a history of bacterial vaginosis, there was no ethnic difference in the occurrence of the condition (adjusted OR, 1.1; 95% CI, 0.5-2.5) . CONCLUSIONS: Ethnic differences in genital hygiene behaviors can explain a twofold increase in the risk of bacterial vaginosis in black Caribbean compared with white women . The role of vulval and vaginal cleaning practices in the development of bacterial vaginosis should be examined further in longitudinal or randomized controlled studies.

Biotechniques, 1999 Aug, 27(2), 321 - 4, 326
Differentiation of hard-to-type bacterial strains by RNA mismatch cleavage; Bricker BJ; Many bacteria are difficult to subtype due to high genetic relatedness . In the cases of pathogens of medical or veterinary importance, subtyping is an essential tool of epidemiologists . This report describes a method for molecular subtyping based on the detection of point mutations without DNA sequencing or specialized equipment . The method, known as RNA mismatch cleavage, hybridizes RNA transcripts derived from PCR-amplified DNA, with a control RNA transcript followed by RNase cleavage at point-mutation mismatches . The method was successful in distinguishing all six Brucella species tested and was able to distinguish 11 of the 18 biovars studied . Of the remaining seven biovars (all of which are Brucella abortus strains), three subgroups were identified . The method should be applicable to all hard-to-subtype bacterial strains.

Infect Immun, 1999 Sep, 67(9), 4834 - 42
The EspD protein of enterohemorrhagic Escherichia coli is required for the formation of bacterial surface appendages and is incorporated in the cytoplasmic membranes of target cells; Kresse AU et al.; The formation of EspA-containing surface appendages in pathogenic Escherichia coli strains, both enteropathogenic E . coli (EPEC) and Shiga toxin-producing E . coli strains, is essential for critical events in the infective process, e.g., localized bacterial adherence to host cells with formation of microcolonies and induction of attaching and effacing lesions . It has been reported that EPEC mutants deficient in the production of EspD, which is encoded by the esp operon, are unable to accumulate actin underneath adherent bacteria but exhibit an attachment similar to that of the wild type . Here, we report the construction and characterization of an in-frame espD deletion mutant of the enterohemorrhagic E . coli (EHEC) strain EDL933 . In contrast to what was observed in EPEC mutants, the EDL933 espD mutant not only lacked the capacity to accumulate actin but also exhibited an impaired attachment to HeLa cells . The synthesis of the EspD protein was also essential for the formation of EspA-containing filaments . Finally, localization studies demonstrated that the EspD protein is transferred to the cytoplasm and integrated into the cytoplasmic membranes of infected cells . These results help to elucidate the underlying molecular events in infections caused by EHEC.

Infect Immun, 1999 Sep, 67(9), 4594 - 602
Murine splenocytes induce severe gastritis and delayed-type hypersensitivity and suppress bacterial colonization in Helicobacter pylori-infected SCID mice; Eaton KA et al.; The goal of this study was to evaluate the role of host immunity in gastritis and epithelial damage due to Helicobacter pylori . Splenocytes from H . pylori-infected and uninfected C57BL/6 mice were adoptively transferred to H . pylori-infected and uninfected severe combined immunodeficient (SCID) mice . Transfer was verified by flow cytometry, and all mice were evaluated for the presence of delayed-type hypersensitivity (DTH) by footpad inoculation with sterile H . pylori sonicate and for humoral immunity by enzyme-linked immunosorbent assay . The severity of gastritis and gastric epithelial damage was quantified histologically, epithelial proliferation was determined by proliferating cell nuclear antigen staining, and colonization was quantified by culture . C57BL/6 mice, but not nonrecipient SCID mice, developed moderate gastritis in response to H . pylori . In contrast, recipient SCID mice developed severe gastritis involving 50 to 100% of the gastric mucosa and strong DTH responses not present in C57BL/6 mice . DTH, but not serum anti-H . pylori immunoglobulin G, correlated with adoptive transfer, gastritis, and bacterial clearance . Severe gastritis, but not bacterial colonization, was associated with epithelial metaplasia, erosions, and an elevated labeling index . This study demonstrates that (i) adaptive immunity is essential for development of gastritis due to H . pylori in mice, (ii) T-cell-enriched lymphocytes in SCID mice induce DTH and gastritis, which is more severe than donor gastritis, and (iii) the host inflammatory response, not direct bacterial contact, causes epithelial damage . The greater severity of gastritis in recipient SCID mice than in donor C57BL/6 mice suggests that gastritis is due to specific T-cell subsets and/or the absence of regulatory cell subsets in the transferred splenocytes.

J Exp Med, 1999 Aug 16, 190(4), 523 - 34
Transport of bacterial lipopolysaccharide to the golgi apparatus; Thieblemont N et al.; Addition of lipopolysaccharide (LPS) to cells in the form of LPS-soluble (s)CD14 complexes induces strong cellular responses . During this process, LPS is delivered from sCD14 to the plasma membrane, and the cell-associated LPS is then rapidly transported to an intracellular site . This transport appears to be important for certain cellular responses to LPS, as drugs that block transport also inhibit signaling and cells from LPS-hyporesponsive C3H/HeJ mice fail to exhibit this transport . To identify the intracellular destination of fluorescently labeled LPS after its delivery from sCD14 into cells, we have made simultaneous observations of different organelles using fluorescent vital dyes or probes . Endosomes, lysosomes, the endoplasmic reticulum, and the Golgi apparatus were labeled using Texas red (TR)-dextran, LysoTrackertrade mark Red DND-99, DiOC6(3), and boron dipyrromethane (BODIPY)-ceramide, respectively . After 30 min, LPS did not colocalize with endosomes, lysosomes, or endoplasmic reticulum in polymorphonuclear leukocytes, although some LPS-positive vesicles overlapped with the endosomal marker, fluorescent dextran . On the other hand, LPS did appear to colocalize with two markers of the Golgi apparatus, BODIPY-ceramide and TRITC (tetramethylrhodamine isothiocyanate)-labeled cholera toxin B subunit . We further confirmed the localization of LPS in the Golgi apparatus using an epithelial cell line, HeLa, which responds to LPS-sCD14 complexes in a CD14-dependent fashion: BODIPY-LPS was internalized and colocalized with fluorescently labeled Golgi apparatus probes in live HeLa cells . Morphological disruption of the Golgi apparatus in brefeldin A-treated HeLa cells caused intracellular redistribution of fluorescent LPS . These results are consistent with the Golgi apparatus being the primary delivery site of monomeric LPS.

Curr Opin Struct Biol, 1999 Aug, 9(4), 455 - 61
Beta-barrel proteins from bacterial outer membranes: structure, function and refolding; Buchanan SK; Recently solved outer membrane protein structures include the smallest and largest known beta-barrel structures, with functions distinct from the general and specific porins . Both protein expressed in outer membranes and protein deposited as cytoplasmic aggregates have been used for the structure determinations . As most beta-barrel proteins can be overexpressed in an aggregated form (inclusion bodies) and refolded to the native state, this provides an alternative to membrane-targeted expression strategies and yields sufficient quantities of protein for future structural studies.

Infect Dis Obstet Gynecol, 1999, 7(4), 190 - 4
Bacterial isolates from patients with preterm labor with and without preterm rupture of the fetal membranes; Mikamo H et al.; OBJECTIVE: The aim of this study is to describe the bacterial flora of women in preterm labor with or without premature rupture of membranes . METHODS: Retrospective studies of 239 patients with preterm labor were performed . RESULTS: One hundred and twenty-three of 239 patients with preterm labor (51.5%) had bacterial vaginosis . Seventy of the 239 patients with preterm labor (29.3%) developed premature rupture of the membranes (preterm PROM) . Of the 70 patients with preterm PROM, 51 (72.9%) had bacterial vaginosis . Therefore, 51 of the 123 patients with bacterial vaginosis (41.5%) developed preterm PROM . An increased number of organisms detected from the vaginal discharge in patients with preterm labor was associated with preterm PROM by Cochran-Armitage test . An increased number of organisms detected from the vaginal discharge in patients with preterm labor complicated with bacterial vaginosis was significantly associated with preterm PROM by Cochran-Armitage test . CONCLUSIONS: In preterm labor, the number of different species detected in the vagina provide sensitive and specific prediction of preterm PROM in patients with preterm labor.

Arch Intern Med, 1999 Aug 9-23, 159(15), 1807 - 10
Wegener granulomatosis simulating bacterial endocarditis; Anthony DD et al.; Cardiac involvement in Wegener granulomatosis is uncommon . We report a case of Wegener granulomatosis that presented as culture-negative endocarditis with aortic valvular vegetation . The clinical manifestations included gingival hyperplasia, gangrenous digital infarcts, mononeuritis multiplex, high fever, inflammatory arthritis, pansinusitis, splenic infarct, and aortic valvular vegetation, which underscore the difficulty of distinguishing systemic vasculitis from bacterial endocarditis . Contrary to the common notion that valvular vegetation is invariably associated with bacterial endocarditis, this case proves that such findings can occur in Wegener granulomatosis as well . Clinicians are guided toward early treatment with corticosteroids and cyclophosphamide to prevent fatal complications.

Curr Opin Immunol, 1999 Aug, 11(4), 400 - 5
T cell responses to bacterial infection; Kerksiek KM et al.; Many exciting advances in our understanding of T cell mediated immunity to bacterial infection have occurred in the past several years . T cell responses have been more fully characterized, due in part to the development of MHC class I tetramers . The importance of cytokines and various effector molecules in defense against infection has come to light . Finally, intracellular bacteria are being exploited to deliver antigens and DNA in an effort to induce immunity to pathogens.

Cancer Res, 1999 Aug 1, 59(15), 3641 - 5
Quinol-glutathione conjugate-induced mutation spectra in the supF gene replicated in human AD293 cells and bacterial MBL50 cells; Jeong JK et al.; Hydroquinone is a nephrocarcinogen in rats but generally tests negative in standard mutagenicity assays . However, 2,3,5-tris-(glutathion-S-yl)hydroquinone, a potent nephrotoxic metabolite of hydroquinone, and 2-bromo-bis-(glutathion-S-yl)hydroquinone, another cytotoxic quinol-glutathione (GSH) conjugate, cause extensive single strand breaks in DNA in a manner that is dependent on the formation of reactive oxygen species . We, therefore, investigated whether quinol-GSH conjugates have the potential to behave as genotoxicants . The shuttle vector pSP189, containing the supF gene, was treated with 2,3,5-tris-(glutathion-S-yl)hydroquinone and replicated in both human AD293 cells and Escherichia coli MBL50 cells . The mutation frequency increased 4.6- and 2.6-fold in human AD293 and bacterial MBL50 cells, respectively . Base substitutions were the major type of mutations, and they occurred predominantly at G:C sites in both cell types . A high frequency of deletions (30%), including < 10- and > 10-bp deletions, were observed in AD293-replicated plasmids . The most common types of mutations in AD293 cells were G:C to A:T transitions (33.8%) and G:C to T:A (29.4%) and G:C to C:G (19.1%) transversions . In MBL50 cells, the major mutations were G:C to T:A (33.8%) and G:C to C:G (31.3%) transversions and G:C to A:T transitions (27.5%) . The mutation spectra were similar to those reported for *OH-induced mutations, suggesting that *OH generated from polyphenolic-GSH conjugates not only plays a role in cytotoxicity but also provides a basis for their mutagenicity and carcinogenicity.

J Microbiol Methods, 1999 Aug, 37(2), 139 - 54
Development of radiographic and microscopic techniques for the characterization of bacterial transport in intact sediment cores from Oyster, Virginia; Dong H et al.; The objective of this study was to ascertain the physical and mineralogical properties responsible for the retention of bacteria in subsurface sediments . The sediment core chosen for this study was a fine-grained, quartz-rich sand with minor amounts of Fe and Al hydroxides . A bacterial transport experiment was performed using an intact core collected from a recent excavation of the Butler's Bluff member of the Nassawadox formation in the borrow pit at Oyster, VA . and a 14C-labeled bacterial strain OYS2-A was selected for its relatively low adhesion . After the bacterial breakthrough was observed in the effluent, the intact core was dissected to determine the internal distribution of the injected bacteria retained in the sediment . The sediment was dried, epoxy fixed, and thin sectioned . The distribution of 14C activity in the thin sections was mapped using a phosphor screen and X-ray film . The remainder of the core was subsampled and the 14C activity of the subsamples was determined by liquid scintillation counting . The phosphor imaging technique was capable of directly imaging the distribution of radiolabeled bacteria in thin sections, because of its high sensitivity and linear response over a large activity range . The phosphor imaging signal intensity was utilized as a measure of bacterial concentration . The distribution of bacteria at the millimeter scale in the thin sections was compared to the grain size, porosity, and mineralogy as measured by scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analyses . No apparent correlation was observed between the retention or collision efficiency of bacteria in the sediment and the amount of Fe and Al hydroxides . This apparent lack of correlation can be qualitatively explained by combination of several factors including a nearly neutral surface charge of the bacterial strain, and texture of the Fe and Al hydroxides in the sediment . The combination of phosphor imaging with SEM-EDS proved to be a robust method for relating the physical and mineralogical microscopic properties of poorly indurated sediment to the distribution of adsorbed bacteria, allowing bacterial retention mechanisms to be unambiguously unraveled.

Allergy, 1999 Jul, 54(7), 722 - 9
Allergen-stimulated expression of CD154 (CD40 ligand) on CD3+ lymphocytes in atopic, but not in nonatopic individuals . Modulation by bacterial lipopolysaccharide; Nakstad B et al.; The intention of this study was to mimic a naturally occurring stimulation by allergens and bacterial infection in order to determine whether specific allergen-induced, inflammatory responses may be changed or modified by bacterial products . Blood leukocytes from six atopic and six nonatopic individuals were examined for their surface expression of CD154, CD11a, and HLA-DR molecules and for secretion of IgE, eosinophil cationic protein (ECP), and the cytokines interleukin (IL)-4 and IL-5 . Signals through CD154 are required for activation and proliferation of effector cells associated with the allergic, inflammatory response . HLA-DR and CD11a/CD18-mediated interactions are also involved in T- and B-cell functions . Birch-pollen (BP) allergens induced CD154 expression on CD3-positive lymphocytes only in atopic individuals . In nonatopics, the expression of CD154 could be induced only after exposure to BP and subsequent lipopolysaccharide (LPS) stimulation . Levels of CD154 expression were always higher in atopics than nonatopics . CD11a and HLA-DR expressions were upregulated, irrespective of atopic state, after BP and/or LPS stimulation . The increased secretion of IL-5 and total IgE in BP-supplemented cell cultures indicated that an allergic response had occurred . In conclusion, the results of this report do not support the hypothesis of a changed inflammatory response stimulated by the combined action of bacteria and allergens, as compared to allergen provocation alone.

Microb Ecol, 1999 Aug, 38(2), 180 - 189
Coupling Bacterial Activity Measurements with Cell Sorting by Flow Cytometry; Servais P et al.; > Abstract A new procedure to investigate the relationship between bacterial cell size and activity at the cellular level has been developed; it is based on the coupling of radioactive labeling of bacterial cells and cell sorting by flow cytometry after SYTO 13 staining . Before sorting, bacterial cells were incubated in the presence of tritiated leucine using a procedure similar to that used for measuring bacterial production by leucine incorporation and then stained with SYTO 13 . Subpopulations of bacterial cells were sorted according to their average right-angle light scatter (RALS) and fluorescence . Average RALS was shown to be significantly related to the average biovolume . Experiments were performed on samples collected at different times in a Mediterranean seawater mesocosm enriched with nitrogen and phosphorus . At four sampling times, bacteria were sorted in two subpopulations (cells smaller and larger than 0.25 microm(3)) . The results indicate that, at each sampling time, the growth rate of larger cells was higher than that of smaller cells . In order to confirm this tendency, cell sorting was performed on six subpopulations differing in average biovolume during the mesocosm follow-up . A clear increase of the bacterial growth rates was observed with increasing cell size for the conditions met in this enriched mesocosm.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p180.html

Luminescence, 1999 Jul-Aug, 14(4), 199 - 200
Mechanisms of the effect of xenobiotics on bacterial bioluminescence; Kudryasheva NS; The influence of xenobiotics on the bioluminescent enzyme system is considered in terms of molecular action on the primary physicochemical processes-energy, electron and hydrogen (e(-) + H(+)) transduction . Dyes, non-fluorescent chemically inert organic compounds, redox-active organic compounds and metallic salts were investigated . The influence of the different xenobiotics depends in a complex way on physicochemical characteristics of the xenobiotic molecules (spectral-luminescent characteristics, electron-acceptation energy and redox potential) .

Pediatr Infect Dis J, 1999 Jul, 18(7), 581 - 90
Prospective, randomized, investigator-blinded study of the efficacy and safety of meropenem vs . cefotaxime therapy in bacterial meningitis in children . Meropenem Meningitis Study Group; Odio CM et al.; OBJECTIVES: To compare the efficacy and safety of meropenem with cefotaxime for the treatment of infants and children with bacterial meningitis . METHODS: Infants and children with strongly suspected or documented bacterial meningitis were randomly assigned in a prospective multicenter study to receive either meropenem or cefotaxime . Patients were assessed at the end of therapy and at 5 to 7 weeks and 5 to 7 months after the end of treatment for the presence of neurologic and sensory neural sequelae . RESULTS: A total of 258 children were randomized to either treatment group . A further 8 patients with suspected pneumococcal meningitis were treated with meropenem without randomization . Of the randomized patients 154 were fully evaluable, 79 in the meropenem group and 75 in the cefotaxime group . At the end of treatment there were no significant differences in clinical outcome between the two treatment groups . Clinical cure with or without sequelae was achieved in 97 and 96% of the meropenem- and cefotaxime-treated patients, respectively . At the end of treatment and at 5 to 7 weeks, 46 and 54% of meropenem patients were cured with no sequelae, respectively . Corresponding results for cefotaxime patients were 56 and 58% . All pathogens were eradicated . In total 37 patients had seizures during treatment, 15 (12%) in the meropenem and 22 (17%) in the cefotaxime group . None of the seizures was considered to be drug-related . CONCLUSIONS: This trial shows that meropenem is suitable therapy for bacterial meningitis in infants and children and that it offers an efficacy and safety profile similar to that of cefotaxime.

Scand J Gastroenterol, 1999 Jun, 34(6), 623 - 8
High prevalence of antibodies to calreticulin of the IgA class in primary biliary cirrhosis: a possible role of gut-derived bacterial antigens in its aetiology?
Kreisel W, Siegel A, Bahler A, Spamer C, Schiltz E, Kist M, Seilnacht G, Klein R, Berg PA, Heilmann C.
BACKGROUND: In a preliminary study we showed that antibodies to the endoplasmic reticulum protein calreticulin (CR) occur in primary biliary cirrhosis (PBC) and autoimmune hepatitis type 1 (AIH) . Since anti-CR antibodies have also been found in patients with infectious diseases, we investigated their prevalence and immunoglobulin classes in patients with various hepatic and intestinal diseases, hoping to get some information on a possible relationship between an infectious trigger and the induction of a certain class of anti-CR antibodies . METHODS: Sera were tested for anti-CR antibodies of the IgA, IgG, and IgM class by Western blotting, using CR isolated from human liver: in autoimmune liver diseases (primary biliary cirrhosis (PBC) (n = 86) and autoimmune hepatitis (AIH) type 1 (n = 57)), alcoholic liver cirrhosis (ALC) (n = 32), viral liver infections (acute hepatitis A (n = 8), acute hepatitis B (n = 20), and chronic hepatitis C (n = 28)), and intestinal diseases (Crohn disease (CD) (n = 30), acute yersiniosis (n = 26)) . Sera from 100 healthy individuals served as negative controls . RESULTS: The most prominent finding was the high prevalence of anti-CR antibodies of the IgA class and the similarity in the anti-CR antibody class pattern in PBC (IgA, 62%; IgG, 43%; IgM, 55%) and yersiniosis (IgA, 62%; IgG, 39%; IgM, 42%) . Class IgA anti-CR antibodies also occurred frequently in ALC (IgA, 44%; IgG, 41%; IgM, 19%) . In contrast, in AIH anti-CR antibodies were predominantly of class IgG (IgA, 28%; IgG, 60%; IgM, 33%) . In hepatitis A anti-CR antibodies were absent . In the other diseases they had a low prevalence and were mostly of class IgG (acute hepatitis B: IgA, 0%; IgG, 15%; IgM, 0%; chronic hepatitis C: IgA, 7%; IgG, 21%; IgM, 0%; CD: IgA, 13%; IgG, 20%; IgM, 13%) . Of the healthy individuals 7% had anti-CR antibodies exclusively of class IgG . CONCLUSIONS: The high prevalence of anti-CR antibodies of class IgA in patients with PBC and yersiniosis as well as in alcoholic liver disease reflects a reactivity of the gut-associated immune system and could imply that a still undefined gut-derived bacterial (?) agent may trigger PBC.

APMIS, 1999 Jul, 107(7), 645 - 54
Formation and structure of mixed bacterial communities; Tetz VV; Mixed bacterial communities are formed by unrelated bacteria on solid media . Mixed bacterial communities on solid media are similar to "classical" colonies and are formed after the growth of a large number of unrelated bacteria simultaneously plated onto a limited area of agar . The morphology of the mixed bacterial communities was similar for different combinations of bacteria and did not change when the bacteria were plated on different media . Different bacterial strains form zones of individual and mixed growth in the structure of mixed bacterial communities . The results of electron microscopic examination indicate that mixed bacterial communities are isolated from their external environment by a surface film . The basic part of this film is formed by an elementary membrane . The membrane of the surface film of mixed bacterial communities is a stable structure occupying a large surface area . The results of this investigation seem to indicate the existence of a special type of co-operation between different species of bacteria . This type of co-operation may be very important in the regulation of interactions between different bacteria and between bacteria and the environment.

Dig Surg, 1999, 16(3), 222 - 8
Bacterial translocation to the thoracic duct in a setting of ischemia, partial resection and reperfusion of the porcine liver; Lemaire LC et al.; BACKGROUND/AIMS: Bacterial translocation is postulated as a risk factor in the development of a systemic inflammatory response syndrome (SIRS) . Research on this topic has focused on the detection of bacteria and endotoxin in blood or mesenteric lymph nodes (MLNs) . We investigated whether bacterial translocation occurs beyond the MLNs into the thoracic duct in a setting of ischemia, partial resection and reperfusion of the porcine liver . METHODS: A porcine model of severe, extra-intestinal tissue injury, consisting of prolonged hepatic ischemia and reperfusion, in combination with hemihepatectomy, was used (experimental group, n = 5 pigs) . To prevent venous congestion of the gut during ischemia, a temporary portal-caval shunt was created . In 5 animals (sham group) a sham portal-caval shunt was constructed while liver ischemia, partial resection and reperfusion were not induced . Thoracic duct lymph, portal blood and systemic blood were collected, and analyzed for the presence of bacteria and endotoxin . RESULTS: In the experimental group, the incidence of bacterial translocation to the thoracic duct was significantly higher during early reperfusion compared to the sham group (5/5 animals versus 1/5 animals, p < 0.05) . CONCLUSION: This study demonstrates bacterial translocation into the thoracic duct . Translocation at this level leads to direct discharge of bacteria and endotoxin into the systemic circulation and therefore, may potentially enhance the development of SIRS.

J Anim Sci, 1999 Jul, 77(7), 1905 - 18
Effects of level of feeding and ruminally undegraded protein on ruminal bacterial protein synthesis, escape of dietary protein, intestinal amino acid profile, and performance of dairy cows; Volden H; Six cannulated lactating cows were used in two replicated, concurrently run 3 x 3 Latin square experiment to study the interaction between level of feeding and diets differing in ruminally undegraded protein (RUP) on bacterial protein synthesis, ruminal escape of dietary protein, and flow of total and individual amino acids (AA) to the small intestine . Treatments consisted of three diets formulated to contain 69 g (HL), 53 g (HH), and 48 g (LL) of RUP per kilogram of DM, respectively . Measurements were made in early lactation, at high feeding level (19.3 kg DM/d), and repeated at late lactation (9.8 kg DM/d, low feeding level) with the same animals and diets . Decreasing feed intake increased (P < .05) the apparent digestibility of OM, NDF, and ADF in the rumen and the total tract, decreased (P < .05) ruminal liquid and particulate passage rate and total ruminal VFA concentration, and increased ruminal pH and ammonia concentration . Decreased level of intake reduced the (P < .05) efficiency of bacterial N synthesis (28.1 vs 23.7 g bacterial N/kg OM truly digested in the rumen) and decreased (P < .05) ruminal protein degradation rate measured with an in situ method . Duodenal flow of nonammonia nitrogen (NAN), and total AA were highest (P < .05) for the HL diet and lowest (P < .05) for the LL diet at the high feeding level . However, at the low feeding level, diet composition did not affect the amount of NAN or total AA passing to the small intestine . Diet HL increased the proportion of Met, His (P < .05), and Arg (P < .07) in the duodenal digesta at both feeding levels . When purines were used to calculate bacterial N synthesis, no differences between diets were detected . However, when diaminopimelic acid was used, highest bacterial N synthesis was detected for diet HH at the high feeding level . Diet HL supported the highest (P < .05) milk protein production at the high feeding level, and the highest (P < .05) milk protein content at the low feeding level . In conclusion, level of feeding and amount of RUP altered the amount and composition of AA presented to the cows.

Br J Biomed Sci, 1998 Dec, 55(4), 253 - 7
Levels of serum immunoglobulin G, CSF IgG and IgG index in acute bacterial meningitis; Giasuddin AS et al.; This study characterised the levels of serum immunoglobulin G (IgG), cerebrospinal fluid IgG (CSF IgG) and IgG index as an aid to the diagnosis and prognosis of acute bacterial meningitis (ABM) . A total of 28 patients with proven ABM at admission (age range: one month to 10 years; 17 males, 11 females) (group A) and 17 age- and sex-matched control children (group B) were studied . Levels were also compared between patients with neurological morbidity (n = 4; group C) and without neurological morbidity (n = 24; group D) who were subsets of group A . In addition, patients were divided randomly into two groups based on the treatment received (i.e . ceftriaxone together with dexamethasone {n = 11; group A1} and ceftriaxone only {n = 9; group A2} to assess the effect of dexamethasone . The results (mean +/- SEM) demonstrated intrathecal synthesis of IgG in ABM (group A vs group B: CSF IgG (mg/L): 92.64 +/- 23.54 vs 2.12 +/- 1.08, P < 0.002; IgG index: 0.959 +/- 0.481 vs 0.029 +/- 0.006, P < 0.001) which showed good diagnostic significance . In the patients with permanent neurological morbidity (group C) vs healthy survivors (group D), the CSF IgG and IgG index showed good prognostic significance (group C vs group D: CSF IgG (mg/L): 10.75 +/- 9.75 vs 106.24 +/- 29.37, P < 0.01; IgG index: 0.046 +/- 0.039 vs 1.132 +/- 0.568, P < 0.05) . Dexamethasone lowered CSF-IgG and IgG-index levels, but the effect was not statistically significant (group A1 vs group A2: P > 0.1).

Biochem J, 1999 Aug 15, 342 ( Pt 1), 97 - 103
Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor 2, and its interaction with HIV-1 matrix; Wilson SA et al.; The cDNA for a human homologue (hIF2) of bacterial (bIF2) and yeast (yIF2) translation initiation factor two (IF2) has been identified during a screen for proteins which interact with HIV-1 matrix . The hIF2 cDNA encodes a 1220-amino-acid protein with a predicted relative molecular mass of 139 kDa, though endogeneous hIF2 migrates anomalously on SDS/PAGE at 180 kDa . hIF2 has an extended N-terminus compared with its homologues, although its central GTP-binding domain and C-terminus are highly conserved, with 58% sequence identity with yIF2 . We have confirmed that hIF2 is required for general translation in human cells by generation of a point mutation in the P-loop of the GTP-binding domain . This mutant protein behaves in a transdominant manner in transient transfections and leads to a significant decrease in the translation of a reporter gene . hIF2 interacts directly with HIV-1 matrix and Gag in vitro, and the protein complex can be immunoprecipitated from human cells . This interaction appears to block hIF2 function, since purified matrix protein inhibits translation in a reticulocyte lysate . hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans.

Clin Infect Dis, 1999 Jul, 29(1), 69 - 74
Predictive value of cerebrospinal fluid (CSF) lactate level versus CSF/blood glucose ratio for the diagnosis of bacterial meningitis following neurosurgery; Leib SL et al.; The value of cerebrospinal fluid (CSF) lactate level and CSF/blood glucose ratio for the identification of bacterial meningitis following neurosurgery was assessed in a retrospective study . During a 3-year period, 73 patients fulfilled the inclusion criteria and could be grouped by preset criteria in one of three categories: proven bacterial meningitis (n = 12), presumed bacterial meningitis (n = 14), and nonbacterial meningeal syndrome (n = 47) . Of 73 patients analyzed, 45% were treated with antibiotics and 33% with steroids at the time of first lumbar puncture . CSF lactate values (cutoff, 4 mmol/L), in comparison with CSF/blood glucose ratios (cutoff, 0.4), were associated with higher sensitivity (0.88 vs . 0.77), specificity (0.98 vs . 0.87), and positive (0.96 vs . 0.77) and negative (0.94 vs . 0.87) predictive values . In conclusion, determination of the CSF lactate value is a quick, sensitive, and specific test to identify patients with bacterial meningitis after neurosurgery.

Trends Microbiol, 1999 Aug, 7(8), 315 - 20
Following the leader: bacterial protein export through the Sec pathway; Economou A; Significant strides have been made during the past 20 years in our understanding of protein secretion across the bacterial inner membrane . Specialized chaperones select secretory polypeptide chains and usher them to a membrane-embedded preprotein translocase . This unique molecular machine envelops the polymeric substrate and migrates along its length in defined, energy-dependent steps . Consequently, preproteins are gradually pumped into the periplasm where they acquire their native, folded conformation.

Proc Natl Acad Sci U S A, 1999 Aug 3, 96(16), 9357 - 62
A high-density physical map of Sinorhizobium meliloti 1021 chromosome derived from bacterial artificial chromosome library; Capela D et al.; As part of the European Sinorhizobium meliloti (strain 1021) chromosome sequencing project, four genomic bacterial artificial chromosome (BAC) libraries have been constructed, one of which was mainly used for chromosome mapping . This library consists of 1,824 clones with an average insert size of 80 kilobases and represents approximately 20-fold total genome coverage {6.8 megabases (Mbs)} . PCR screening of 384 BAC clones with 447 chromosomal markers (PCR primer pairs), consisting of 73 markers representing 118 genes (40 individual genes and 78 genes clustered in 23 operons), two markers from the rrn operon (three loci), four markers from insertion sequences (approximately 16 loci) and 368 sequence-tagged sites allowed the identification of 252 chromosomal BAC clones and the construction of a high-density physical map of the whole 3.7-Mb chromosome of S . meliloti . An average of 5.5 overlapping and colinear BAC clones per marker, correlated with a low rate of deleted or rearranged clones (0.8%) indicate a solid BAC contigation and a correct mapping . Systematic BLASTX analysis of sequence-tagged site marker sequences allowed prediction of a biological function for a number of putative ORFs . Results are available at . This map, whose resolution averages one marker every 9 kilobases, should provide a valuable tool for further sequencing, functional analysis, and positional cloning.

Genetics, 1999 Aug, 152(4), 1459 - 74
Adapt globally, act locally: the effect of selective sweeps on bacterial sequence diversity; Majewski J et al.; Previous studies have shown that genetic exchange in bacteria is too rare to prevent neutral sequence divergence between ecological populations . That is, despite genetic exchange, each population should diverge into its own DNA sequence-similarity cluster . In those studies, each selective sweep was limited to acting within a single ecological population . Here we postulate the existence of globally adaptive mutations, which may confer a selective advantage to all ecological populations constituting a metapopulation . Such adaptations cause global selective sweeps, which purge the divergence both within and between populations . We found that the effect of recurrent global selective sweeps on neutral sequence divergence is highly dependent on the mechanism of genetic exchange . Global selective sweeps can prevent populations from reaching high levels of neutral sequence divergence, but they cannot cause two populations to become identical in neutral sequence characters . The model supports the earlier conclusion that each ecological population of bacteria should form its own distinct DNA sequence-similarity cluster.

Hepatogastroenterology, 1999 May-Jun, 46(27), 2057 - 62
Quantitative result of 13C urea breath test at 15 minutes may correlate with the bacterial density of H . pylori in the stomach; Sheu BS et al.; BACKGROUND/AIMS: We tried to test the diagnostic efficacy of a new 13C-labeled urea agent made in Taiwan for urea breath test (UBT) of H . pylori infection, and to assess the correlation between the bacterial load of H . pylori in the stomach and the results of UBT from different timings . METHODOLOGY: One hundred and ninety-six dyspeptic patients without usage of antibiotics and proton pump inhibitors in the last 4 weeks were recruited for endoscopy, which included CLO test and H . pylori culture . Three additional bits of gastric biopsy (each one from antrum, body, and cardia) were taken for histology to assess the H . pylori density (HPD, range 0-5) in each specimen and the total bacterial density (TBD, a sum of HPD from three sites, range 0-15) . Every study patient had been assigned to complete the UBT protocol . The gas samplings of UBT at baseline, 15 min and 30 min after ingestion of 100 mg 13C-labeled urea (INER-Hp 13C-tester, Taiwan) were collected for the ratio of 13CO2/12CO2 and labeled A, B, and C respectively . Both delta15 (B minus A) & delta30 (C minus A) were recorded to express the excess delta13CO2 per milliliter . During the 30 min period of UBT, the patient was scheduled to change lying positions every 5 minutes for even coating of the stomach with test agent . RESULTS: Based on two positive results of three invasive methods (CLO test, culture, and histology), 91 cases were confirmed to have H . pylori infection . The diagnostic efficacy of UBT was quite good with 96.7% sensitivity for both delta15 and delta30, and with 97.1% and 96.2% specificity for delta15 and delta30 respectively . Both delta15 and delta30 of UBT were well correlated with the TBD of H . pylori in histology (delta15: r=0.7574; delta30: r=0.7432, p<0.0001) . CONCLUSIONS: The new C13-labeled urea for UBT can achieve a high diagnostic yield for H . pylori infection . Furthermore, the density of H . pylori in the stomach can be assessed indirectly by UBT by applying 15-minute gas sampling.

FEMS Microbiol Lett, 1999 Jul 15, 176(2), 269 - 77
Proteic toxin-antitoxin, bacterial plasmid addiction systems and their evolution with special reference to the pas system of pTF-FC2; Rawlings DE; Genes encoding toxin-antitoxin proteins are frequently found on plasmids where they serve to stabilize the plasmid within a bacterial population . The toxin-antitoxin proteins do not increase the likelihood of a progeny cell receiving a plasmid but rather function as post-segregational killing mechanisms which decrease the proportion of cells that survive after losing the plasmid . These toxin-antitoxin couples therefore act as plasmid addiction systems . Several new proteic toxin-antitoxin systems have been identified and these systems appear to be ubiquitous on the chromosomes of bacteria and archaea . When placed on plasmids, these chromosomal systems also have the ability to stabilize plasmids and in at least one case, chromosomal- and plasmid-based toxin-antitoxin systems have been shown to interact . Recent findings regarding toxin-antitoxin systems and questions that have arisen as a result of these findings are reviewed.

Appl Environ Microbiol, 1999 Aug, 65(8), 3735 - 7
Improved method for purification of bacterial DNA from bovine milk for detection of Brucella spp . by PCR; Romero C et al.; Different methods of extraction of bacterial DNA from bovine milk to improve the direct detection of Brucella by PCR were evaluated . We found that the use of a lysis buffer with high concentrations of Tris, EDTA, and NaCl, high concentrations of sodium dodecyl sulfate and proteinase K, and high temperatures of incubation was necessary for the efficient extraction of Brucella DNA . The limit of detection by PCR was 5 to 50 Brucella CFU/ml of milk.

J Hepatol, 1999 Jul, 31(1), 18 - 26
Inhibition of concanavalin A-induced hepatic injury of mice by bacterial lipopolysaccharide via the induction of IL-6 and the subsequent reduction of IL-4: the cytokine milieu of concanavalin A hepatitis; Nishikage T et al.; BACKGROUND/AIMS: Liver natural killer 1.1 antigen (NK1)+ T cells and IL-4 play a crucial role in concanavalin-A (Con-A)-induced hepatic injury in mice, and a T helper (Th) 2 immune response was thus suggested to be involved . This study was designed to examine the effect of bacterial lipopolysaccharide (LPS), a strong inducer of a Th 1 immune response, on Con-A hepatic injury and also to clarify further the cytokine milieu of Con-A hepatitis . Methods: LPS were injected into mice before Con-A injection to evaluate the effect on hepatic injury . The effect of the pretreatment with various T1 and Th2 cytokines or anti-cytokine antibodies on Con-A hepatitis was also examined . Results: LPS in quantities > or = 500 ng/mouse, when injected 24 h before Con-A injection, abrogated the Con-A-induced elevation of transaminases, hepatocyte destruction and serum IL-4 elevation . This LPS inhibitory effect was blocked when the mice were injected with either anti-IL-6 antibody before LPS injection or IL-4 before Con-A injection . IL-6, but neither IL-10 nor IL-12 pretreatment suppressed Con-A-induced IL-4 production and hepatitis . NK1+ T cells produced IL-4 while both NK1+ T cells and NK1- T cells produced IFN-gamma . Not only anti-IL-4 antibody but also the anti-IFN-gamma antibody pretreatment inhibited Con-A hepatitis . However, although the anti-IL4 antibody suppressed IL-4 alone, the anti-IFN-gamma Ab unexpectedly inhibited both IFN-gamma and IL-4 elevation, while IL-4 injection evoked a moderate Con-A hepatitis even in the anti-IFN-gamma antibody-treated mice . Furthermore, the IL-4 mutant mice did not develop Con-A hepatitis . CONCLUSION: LPS inhibited Con-A hepatitis by inducing IL-6 and thereby inhibited IL-4 synthesis from NK1+ T cells . Although both IL-4 and IFN-gamma were required for the full induction of Con-A hepatic injury, exogenous IL-4 evoked a moderate Con-A hepatitis, even in the absence of IFN-gamma.

J Vet Med Sci, 1999 Jun, 61(6), 609 - 13
Decrease in hepatic CYP2C11 mRNA and increase in heme oxygenase activity after intracerebroventricular injection of bacterial endotoxin; Shimamoto Y et al.; We previously reported (Arch . Toxcol . 1998, 72, 492-498) that the differential decrease in the levels of hepatic cytochrome P450 (CYP) isozymes in rats was observed 24 hr after intracerebroventricular (i.c.v.) injection of bacterial lipopolysaccharide (LPS) at the dose ineffective (0.1 microgram) when injected intraperitoneally (i.p.) . Among CYP isozymes we examined, the male specific CYP isozyme, CYP2C11 was most severely affected by i.c.v . injection of LPS . In this study, we examined the gene expression of CYP2C11, the total P450 contents, the CYP2C11-dependent activity of imipramine N-demethylase (IMND) and protein of CYP2C11 10 hr after i.c.v . or i.p . injections of LPS . Intracerebroventricular injection of LPS significantly decreased the level of CYP2C11 mRNA (to 63% of saline i.c.v . control), the total P450 contents (to 70% of saline i.c.v . control), the IMND activity (to 74% of saline i.c.v . control), but not protein of CYP2C11 in rat liver . In contrast, i.p . injection of LPS at the same dose as i.c.v . did not significantly affect these parameters . Since CYP is a heme protein, we also measured the activity of heme oxygenase (HO) using the same rat liver microsomes . The HO activity was increased to 166% by i.c.v . injection of LPS and 135% by i.p . injection of LPS compared to corresponding saline control . It is suggested that i.c.v . injection of LPS down-regulates the expression of CYP2C11 at transcriptional level and that both the decrease in CYP2C11 mRNA and the increase in heme degradation may be involved in the decreased level of protein and activity of CYP2C11 by i.c.v . injection of LPS in rat liver.

J Med Virol, 1999 Aug, 58(4), 338 - 45
Bacterial expression of a human recombinant monoclonal antibody fab fragment against hepatitis B surface antigen; Maeda F et al.; The Fab fragment was cloned from the monoclonal cell line TAPC301-CL4, which was produced using the Epstein-Barr virus (EBV) transformation method . This cell line produces a human monoclonal antibody (CL4MAb) against the hepatitis B surface antigen (HBsAg) . This MAb was shown to have hepatitis B virus (HBV) neutralizing activity in chimpanzees . The Fab fragment was produced by subjecting the heavy and light chain antibody genes of the TAPC301-CL4 cell line to reverse transcription-polymerase chain reaction, cloning the products in the plasmid vector pFab1-His2 and introducing the plasmid into bacteria . Sequence analyses of the CL4Fab fragment revealed that the light and heavy chains belong to the Vk3a and VH3 groups of the immunoglobulin (Ig) family, respectively . An enzyme-linked immunosorbent assay confirmed that specificity of the recombinant CL4Fab antibody against HBsAg was the same as that of the parental MAb . Flow cytometric analysis using PLC/PRF/5 (Alexander) cells, which express HBsAg, showed the reactivities of the CL4MAb and CL4Fab antibody were the same . These results suggest that the recombinant CL4Fab antibody produced by Escherichia coli using the new vector-primer system developed for human IgG Fab fragments has a very high affinity for the HBsAg and may be useful clinically . A source for generation of human MAb for human therapy with very stable and specific expression was thus produced by isolating antibodies from EBV-transformed cell lines.

Photochem Photobiol, 1999 Jul, 70(1), 116 - 22
Computational analysis of the oxygen addition at the C4a site of reduced flavin in the bacterial luciferase bioluminescence reaction; Wada N et al.; The energetic characteristics of selected reaction steps in the bacterial luciferase-catalyzed luminescence reaction were examined by computation using the MNDO-PM3 method . Specifically, a three-step model was proposed to account for the reaction between oxygen and reduced riboflavin 5'-phosphate (1,5H2-FMN) to generate first the 5-hydroFMN-4a-peroxide (5H-FMN-4aOO-) and then the 5-hydro-4a-hydroperoxyFMN (5H-FMN-4aOOH) intermediates . Lysine (Lys-H+) and aspartate (Asp-) were chosen as representative catalytic residues involved in the protonation and deprotonation processes . Results show that deprotonation at the N1 site of 1,5H2-FMN by a basic amino acid residue at the luciferase active site would efficiently accelerate the reaction rate of O2 addition to form 5H-FMN-4aOO- . The most favored site of oxygen attack is at the flavin C4a . With the aid of a catalytic acid group, the 5H-FMN-4aOO- so formed tends to undergo a spontaneous protonation reaction to yield the 5H-FMN-4aOOH.

Mol Microbiol, 1999 Aug, 33(3), 499 - 509
The type IV bundle-forming pilus of enteropathogenic Escherichia coli undergoes dramatic alterations in structure associated with bacterial adherence, aggregation and dispersal; Knutton S et al.; BFP, a plasmid-encoded type IV bundle-forming pilus produced by enteropathogenic Escherichia coli (EPEC), has recently been shown to be associated with the aggregation of bacteria and dispersal of bacteria from bacterial microcolonies . In standard 3 h HEp-2 cell assays, EPEC adhere in localized microcolonies; after 6 h, bacterial microcolonies are no longer present, indicating that bacterial aggregation and dispersal occurs in vitro during EPEC adhesion to cultured epithelial cells . To examine the role of BFP in EPEC aggregation and dispersal, we examined HEp-2 cell adhesion of strain E2348/69 and defined E2348/69 mutants by immunofluorescence and immunoelectron microscopy . BFP was expressed initially as approximately 40 nm diameter pilus bundles that promoted bacteria-bacteria interaction and microcolony formation . BFP subsequently underwent a striking alteration in structural organization with the formation of much longer and thicker ( approximately 100 nm diameter) pilus bundles, which frequently aggregated laterally to form even thicker bundles often arranged in a loose three-dimensional network; EPEC dispersal from bacterial microcolonies was associated with this transformation of BFP from thin to thick bundles . Bacterial dispersal and transformation of BFP from thin to thick bundles did not occur with a bfpF mutant of strain E2348/69 . It is concluded that BFP promotes both the formation and the dispersal of EPEC microcolonies, that the dispersal phase requires BfpF and that dispersal is associated with dramatic alterations in the structure of BFP bundles.

BMJ, 1999 Jul 24, 319(7204), 220 - 3
Influence of bacterial vaginosis on conception and miscarriage in the first trimester: cohort study; Ralph SG et al.; OBJECTIVES: To assess whether bacterial vaginosis affects the rates of conception and miscarriage in the first trimester . DESIGN: Cohort study . SETTING: Assisted conception unit of a teaching hospital in Leeds . PARTICIPANTS: 867 consecutive women undergoing in vitro fertilisation . INTERVENTIONS: Screening for bacterial vaginosis with a Gram stained vaginal smear before egg collection . MAIN OUTCOME MEASURES: The presence of bacterial vaginosis or normal vaginal flora, and the rate of conception and miscarriage in the first trimester . RESULTS: 190 of 771 (24.6%) women had bacterial vaginosis . No difference in conception rate was found between those women with bacterial vaginosis and those with normal vaginal flora: 61 women (32.1%) and 146 of 493 women (29.6%) respectively (relative risk 1 . 08, 95% confidence interval 0.85 to 1.39; odds ratio 1.12, 0.77 to 1 . 64) . However, 22 women (31.6%) with bacterial vaginosis who conceived had a significantly increased risk of miscarriage in the first trimester compared with 27 women (18.5%) with normal vaginal flora (crude relative risk 1.95, 1.11 to 3.42; crude odds ratio 2.49, 1.21 to 5.12) . This increased risk remained significant after adjustment for factors known to increase the rate of miscarriage: increasing maternal age, smoking, history of three or more miscarriages, no previous live birth, and polycystic ovaries (adjusted relative risk 2.03, 1.09 to 3.78; adjusted odds ratio 2.67, 1.26 to 5.63) . CONCLUSIONS: Bacterial vaginosis does not affect conception but is associated with an increased risk of miscarriage in the first trimester in women undergoing in vitro fertilisation, independent of other risk factors.

Brain Pathol, 1999 Jul, 9(3), 481 - 93
Exacerbation of viral and autoimmune animal models for multiple sclerosis by bacterial DNA; Tsunoda I et al.; Theiler's murine encephalomyelitis virus (TMEV) infection and relapsing-remitting experimental allergic encephalomyelitis (R-EAE) have been used to investigate the viral and autoimmune etiology of multiple sclerosis (MS), a possible Th1-type mediated disease . DNA immunization is a novel vaccination strategy in which few harmful effects have been reported . Bacterial DNA and oligodeoxynucleotides, which contain CpG motifs, have been reported to enhance immunostimulation . Our objectives were two-fold: first, to ascertain whether plasmid DNA, pCMV, which is widely used as a vector in DNA immunization studies, could exert immunostimulation in vitro; and second, to test if pCMV injection could modulate animal models for MS in vivo . We demonstrated that this bacterially derived DNA could induce interleukin (IL)-12, interferon (IFN)gamma, (Th1-promoting cytokines), and IL-6 production as well as activate NK cells . Following pCMV injections, SJL/J mice were infected with TMEV or challenged with encephalitogenic myelin proteolipid protein (PLP) peptides . pCMV injection exacerbated TMEV-induced demyelinating disease in a dose-dependent manner . Exacerbation of the disease did not correlate with the number of TMEV-antigen positive cells but did with an increase in anti-TMEV antibody . pCMV injection also enhanced R-EAE with increased IFNgamma and IL-6 responses . These results caution the use of DNA vaccination in MS patients and other possible Th1-mediated diseases.

Int J Biol Macromol, 1999 Jun-Jul, 25(1-3), 193 - 200
Chemical composition distribution of bacterial copolyesters; Yoshie N et al.; Poly(3-hydroxybutyrate) {P(3HB)} and its copolymers with hydroxyalkanoates are naturally occurring thermoplastic materials produced by bacteria . There are many potential uses for these copolyesters owing to their biodegradability and biocompatibility . The physical properties of the copolyesters vary depending on the chemical structure as well as the composition of the comonomers . Usually, we expect, copolymers to have a narrow chemical composition distribution (CCD) . Several reports, however, have pointed out that some bacterial copolyesters have broad and/or multimodal CCD . Fractionation based on the chemical composition has also been reported for several bacterial copolyester samples . In this review, the literature concerning CCD and fractionation based on chemical composition is summarized . The width of CCD is approximated based on the data of diad sequence distribution . Generality of the complex CCD in bacterial copolyesters is also discussed.

Ann N Y Acad Sci, 1999 May 18, 870, 314 - 29
Detecting alien genes in bacterial genomes; Mrazek J et al.; We present new methods for calculating codon bias of a group of genes or an individual gene relative to a standard gene class . This method is suitable for identifying alien (e.g., horizontally transferred) and highly expressed genes . In yeast and several bacterial genomes, highly expressed genes typically include ribosomal protein genes, elongation factors, chaperonins (heat shock proteins), and a subset of genes involved in glycolysis generally essential in exponential growth . Highly expressed genes of the Synechocystis genome feature several photosystem II genes, and highly expressed genes in several methanogens (Methanococcus jannaschii, M . thermoautotrophicum) are essential for methanogenesis . Alien genes mostly consist of ORFs of unknown function, transposases, prophage genes, and restriction/modification enzymes . Notably, nuclear ribosomal proteins of yeast are highly expressed, whereas mitochondrial ribosomal protein genes appear to be alien genes . Alien genes often occur in clusters, suggesting in these cases that transfer events entail several genes.

Ann N Y Acad Sci, 1999 May 18, 870, 36 - 44
Involvement of gene products in bacterial evolution; Arber W; Three strategies of different quality contribute in parallel to the natural formation of genetic variants in bacteria: (1) small local alterations of DNA sequences; (2) recombinational reshuffling of segments of the genome; and (3) acquisition of DNA sequences by horizontal gene transfer . Key enzymes involved in these processes often act as variation generators by making use of structural flexibilities of biological macromolecules and of the effect of random encounter . In the theory of molecular evolution, genetic determinants of variation generators as well as of modulators of the frequency of genetic variation are defined as evolutionary genes . This postulate is consistent with the notion that spontaneous mutagenesis is in general not adaptive and that the direction of evolution depends on natural selection exerted on populations of genetic variants.

Gene, 1999 Jul 22, 235(1-2), 13 - 8
Sequence and expression analysis of a novel Xenopus laevis cDNA that encodes a protein similar to bacterial and chloroplast ribosomal protein L24; Kousteni S et al.; We report here the cloning and the characterization of a Xenopus laevis cDNA that encodes a basic protein of 276 amino acids with a central core region, which shows a substantial degree of homology to bacterial and chloroplast ribosomal protein L24, and additional diverged N- and C-terminal polypeptide extensions . The N-terminal extension displays similarities to the mitochondrial targetting sequence, thereby suggesting that the cDNA probably codes for a mitochondrial ribosomal protein . Although the gene was expressed ubiquitously, at fairly constant levels, during embryogenesis, the abundance of the transcripts in the different tissues varies with the mRNA levels in the kidney, adipose tissue, muscle and liver being greater than that present in the brain, heart, ovary and lung.

Arch Biochem Biophys, 1999 Aug 1, 368(1), 156 - 60
Escherichia coli membrane fluidity as detected by excimerization of dipyrenylpropane: sensitivity to the bacterial fatty acid profile; Mejia R et al.; A coordinated study of membrane fluidity and fatty acid composition has been carried out in Escherichia coli W3110 . The lipid acyl chain profile of the bacteria, altered by growing cells in steady state at 30, 37, 42, or 45 degrees C, was determined by gas chromatography of the fatty acid methyl esters . In parallel experiments, total membranes obtained from cells of the above-mentioned cultures were labeled with dipyrenylpropane and their relative fluidity was measured on the basis of the excimer to monomer fluorescence intensity ratio of the fluorophore . It has been found that, at constant assay temperature, fluidity determined with dipyrenylpropane decreases gradually with the growth temperature increment, from 30 to 45 degrees C . Interestingly, when fatty acid composition is taken into account, fluidity increases linearly in the range under study, with the proportion of unsaturated fatty acyl chains, both variables being highly correlated (0.924 </= r(2) </= 0.996) . Our results show that dipyrenylpropane is a reliable and quantitative indicator of changes in membrane fluidity, driven by modifications in the acyl chain composition of bacterial lipids .

Rev Assoc Med Bras, 1999 Apr-Jun, 45(2), 128 - 36
{Spontaneous bacterial peritonitis in hepatic cirrhosis: prevalence, predictive factors and prognosis}; Figueiredo FA et al.; BACKGROUND: Spontaneous Bacterial Peritonitis (SBP) is a common and potentially fatal complication of cirrhosis . Multiple variants of this infection have been described during the past decade . Few studies have investigated SBP in Brazil . MATERIAL AND METHOD: In order to investigate prospectively prevalence, predictive factors and prognosis of the episode of SBP, we studied 143 in and outpatients with cirrhosis admitted to HUCFF and HUPE between January, 1995 and January, 1996 . All patients were submitted to a questionnaire, physical examination, blood analysis and abdominal paracentesis with ascitic fluid analysis . They were followed for a mean follow-up period of 4 months and survival was determined . RESULTS: The prevalence of SBP was 20% . Culture-positive SBP, Culture-negative Neutrocytic Ascites and Bacterascites were identified in 24%, 66% and 10%, respectively . After uni- and multivariate analysis, only anterior gastrointestinal hemorrhage, serum albumin and ascitic fluid C4 reached statistical significance (p = 0.05) as predictive factors for the development of the SBP . The in-hospital and follow-up mortality rates were 33.3% and 53.8% for the SBP patients and 8.5% and 31.9% for the non-SBP patients, respectively (p = 0.01 and p = 0.04) . The cumulative probability of survival in the SBP group was significantly lower than the probability of the non-SBP group (p = 0.05) . CONCLUSIONS: We conclude that SBP is a frequent complication, depends of the severity of liver failure and is a marker for poor prognosis in patients with liver cirrhosis.

Plant Mol Biol, 1999 May, 40(2), 279 - 88
Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase; Alia et al.; Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis . This gene encodes choline oxidase, an enzyme that converts choline to glycinebetaine . The photosynthetic activity, monitored in terms of chlorophyll fluorescence, of transformed plants was more tolerant to light stress than that of wild-type plants . This enhanced tolerance to light stress was caused by acceleration of the recovery of the photosystem II (PS II) complex from the photo-inactivated state . The transformed plants synthesized glycinebetaine, but no changes were detected in the relative levels of membrane lipids or in the relative levels of fatty acids in the various membrane lipids . Transformation with the codA gene increased levels of H2O2, a by-product of the reaction catalyzed by choline oxidase, by only 50% to 100% under stress or non-stress conditions . The activity of ascorbate peroxidase and, to a lesser extent, that of catalase in transformed plants were significantly higher than in the wild-type plants . These observations suggest that H2O2 produced by choline oxidase in the transformed plants might have stimulated the expression of H2O2 scavenging enzymes, with resultant maintenance of the level of H2O2 within a certain limited range . It appears that glycinebetaine produced in vivo, but not changes in membrane lipids or in the level of H2O2, protected the PS II complex in transformed plants from damage due to light stress.

J Investig Allergol Clin Immunol, 1999 May-Jun, 9(3), 178 - 82
Effect of bacterial antigen lysate on IgG and IgA levels in children with recurrent infections and hypogammaglobulinemia; Quezada A et al.; To evaluate the effect of bacterial antigen lysate on serum immunoglobulin (Ig) levels, we studied 14 children with recurrent infections and hypogammaglobulinemia (IgG and IgA levels below 2 standard deviations for age) . Patients were treated for a 60-90 day period with OM-85 BV and reevaluated both clinically and by measuring serum Ig levels at the end of follow-up . The control group consisted of 10 children with recurrent infections who received a placebo . Serum Ig levels were also compared with the reference values for age . The Wilcoxon and Mann-Whitney tests were used for statistical analysis . In the study group, IgG (pretreatment: 707 mg/dl; post-treatment: 1,022 mg/dl; p < 0.004) and IgA levels (pretreatment: 41 mg/dl; post-treatment: 83 mg/dl; p < 0.018) increased significantly . Furthermore, 13/14 children reached normal IgG levels, and 12/14 children reached normal age levels for serum IgA . Similarly, when comparing the pre- and post-treatment levels in the study group with the levels in the control group, they were significant for IgG (p < 0.002) as well as IgA levels (p < 0.04) . The overall clinical response was favorable in all patients in the treated group . These results suggest an immunostimulant effect of OM-85 BV, both improving Ig levels and reducing recurrent infections.

Proc Natl Acad Sci U S A, 1999 Jul 20, 96(15), 8455 - 60
The kinetoplast structure-specific endonuclease I is related to the 5' exo/endonuclease domain of bacterial DNA polymerase I and colocalizes with the kinetoplast topoisomerase II and DNA polymerase beta during replication; Engel ML et al.; The mitochondrial DNA (kinetoplast DNA) of the trypanosomatid Crithidia fasciculata has an unusual structure composed of minicircles and maxicircles topologically interlocked into a single network and organized in a disc-shaped structure at the base of the flagellum . We previously purified a structure-specific endonuclease (SSE1), based on its RNase H activity, that is enriched in isolated kinetoplasts . The endonuclease gene has now been cloned, sequenced, and found to be closely related to the 5' exonuclease domain of bacterial DNA polymerase I proteins . Although the protein does not contain a typical mitochondrial leader sequence, the enzyme is shown to colocalize with a type II DNA topoisomerase and a DNA polymerase beta at antipodal sites flanking the kinetoplast disc . Cell synchronization studies with an epitope-tagged construct show that the localization of the endonuclease to the antipodal sites varies in a cell cycle-dependent manner similar to that of the DNA polymerase beta {Johnson, C . E . & Englund, P . T . (1998) J . Cell Biol . 143, 911-919} . Immunofluorescent localization of SSE1 to the antipodal sites is only observed during kinetoplast replication . Together, these results suggest a point of control for kinetoplast DNA replication through the regulation of the availability of DNA replication proteins and a possible role for the antipodal sites in removal of RNA primers and the repair of gaps in newly replicated minicircles.

J Leukoc Biol, 1999 Jul, 66(1), 172 - 82
Regulation of the plasminogen activator inhibitor-2 (PAI-2) gene in murine macrophages . Demonstration of a novel pattern of responsiveness to bacterial endotoxin; Costelloe EO et al.; We investigate the regulation of plasminogen activator inhibitor-2 (PAI-2) in murine macrophages . PAI-2 mRNA was inducible by bacterial lipopolysaccharide (LPS) in primary cells and macrophage-like cell lines . Evidence is presented for a role for autocrine factors, including cyclooxygenase products but not the cytokines tumor necrosis factor alpha or interferon-beta (IFN-beta) . PAI-2 mRNA levels generally varied inversely from those of its target, urokinase-type plasminogen activator (uPA), and the macrophage growth factor CSF-1, which induces uPA, inhibited PAI-2 expression in cells treated subsequently with LPS . Expression of PAI-2 was distinct from that of other LPS-inducible genes in terms of induction time course, LPS dose response, and sensitivity to co-stimulation with IFN-gamma . Induction of PAI-2 mRNA in subclones of the cell line RAW 264 was not uniform, reflecting heterogeneous expression in the parent line . The expression pattern of PAI-2 is discussed in terms of a possible role in LPS-induced pathology such as septicemia.

Annu Rev Biophys Biomol Struct, 1999, 28, 269 - 93
Structure and conformation of complex carbohydrates of glycoproteins, glycolipids, and bacterial polysaccharides; Bush CA et al.; For nuclear magnetic resonance determinations of the conformation of oligosaccharides in solution, simple molecular mechanics calculations and nuclear Overhauser enhancement measurements are adequate for small oligosaccharides that adopt single, relatively rigid conformations . Polysaccharides and larger or more flexible oligosaccharides generally require additional types of data, such as scalar and dipolar coupling constants, which are most conveniently measured in 13C-enriched samples . Nuclear magnetic resonance relaxation data provide information on the dynamics of oligosaccharides, which involves several different types of internal motion . Oligosaccharides complexed with lectins and antibodies have been successfully studied both by X-ray crystallography and by nuclear magnetic resonance spectroscopy . The complexes have been shown to be stabilized by a combination of polar hydrogen bonding interactions and van der Waals attractions . Although theoretical calculations of the conformation and stability of free oligosaccharides and of complexes with proteins can be carried out by molecular mechanics methods, the role of solvent water for these highly polar molecules continues to present computational problems.

J Biol Chem, 1999 Jul 23, 274(30), 21049 - 55
Bacterial lipopolysaccharide induces expression of the stress response genes hop and H411; Heine H et al.; CD14-transfected Chinese hamster ovary K1 fibroblasts (CHO/CD14) respond to lipopolysaccharide (LPS) by metabolizing arachidonic acid and with translocation of NF-kappaB to the nucleus . Although previous experiments failed to identify the production of tumor necrosis factor-alpha and interleukin (IL)-1beta by CHO/CD14 cells, LPS did induce the expression of IL-6 mRNA and the subsequent release of the IL-6 protein . To identify additional LPS-inducible genes, a cDNA library derived from LPS-stimulated CHO/CD14 cells was screened by subtractive hybridization . Fourteen genes were found to be expressed differentially, and two were analyzed in detail: hop (Hsp70/Hsp90-organizing protein), which is the hamster homologue of the stress-inducible yeast gene, STI1, and clone H411, which encodes a novel LPS-inducible growth factor . In response to LPS, the expression of Hop mRNA was also increased in both the murine macrophage cell line, RAW 264.7, as well as in primary hamster macrophages . This suggested that the up-regulation of Hop expression is part of the macrophage stress response to LPS . Clone H411 encodes a protein in the epidermal growth factor-like repeat protein family . Overexpression of H411 cDNA in the RAW 264.7 macrophage cell line promoted an increased growth rate, suggesting that expression of H411 is part of the proliferative cell response to LPS . Both Hop and H411 represent novel gene products not previously recognized as part of the complex biological response to endotoxin.

Am J Physiol, 1999 Jul, 277(1 Pt 1), G245 - 55
Bacterial cell wall polymers promote intestinal fibrosis by direct stimulation of myofibroblasts; van Tol EA et al.; Normal luminal bacteria and bacterial cell wall polymers are implicated in the pathogenesis of chronic intestinal inflammation . To determine the direct involvement of bacteria and their products on intestinal fibrogenesis, the effects of purified bacterial cell wall polymers on collagen and cytokine synthesis were evaluated in intestinal myofibroblast cultures established from normal fetal and chronically inflamed cecal tissues . In this study, the intestines of Lewis rats were intramurally injected with peptidoglycan-polysaccharide polymers . Collagen and transforming growth factor (TGF)-beta1 mRNA levels were measured and correlated with mesenchymal cell accumulation by immunohistochemistry . The direct effects of cell wall polymers on fibrogenic cytokine and collagen alpha1 (type I) expression were evaluated in intestinal myofibroblast cultures . We found that intramural injections of bacterial cell wall polymers induced chronic granulomatous enterocolitis with markedly increased collagen synthesis and concomitant increased TGF-beta1 and interleukin (IL)-6 expression . Intestinal myofibroblast cultures were established, which both phenotypically and functionally resemble the mesenchymal cells that are involved in fibrosis in vivo . Bacterial cell wall polymers directly stimulated collagen alpha1 (I), TGF-beta1, IL-1beta, and IL-6 mRNA expression in the intestinal myofibroblasts derived from both normal and inflamed cecum . Neutralization of endogenous TGF-beta1 inhibited in vitro collagen gene expression . From our results, we conclude that increased exposure to luminal bacterial products can directly activate intestinal mesenchymal cells, which accumulate in areas of chronic intestinal inflammation, thus stimulating intestinal fibrosis in genetically susceptible hosts.

Diagn Cytopathol, 1999 Jul, 21(1), 10 - 3
Routine Pap smears for the diagnosis of bacterial vaginosis; Prey M; This study investigated the role of Papanicolaou (Pap) smears in determining the presence of bacterial vaginosis (BV) . Pap results, vaginal Gram stains, signs, symptoms, and wet mounts were evaluated . Vaginal smears for Gram stain and routine Pap smears were collected from 420 consecutive patients . Ninety-three percent of patients with Pap smears showing only coccobacilli had a corresponding BV-positive Gram stain . Pap smears with mixed bacterial patterns had 22-71% positive Gram stains depending on the types of bacteria present . Only 10 of 70 symptomatic patients and 13 of 132 with cervicitis or discharge had a positive Gram stain and/or an altered bacterial pattern . All positive wet mounts had positive Gram stains and coccobacilli only on Pap smears . The most specific diagnosis of BV with Pap smears requires coccobacilli only . This reiterates the Bethesda system criteria . Clinical signs, physical symptoms, and wet-mount examinations were noncontributory in this study.

Perit Dial Int, 1999, 19 Suppl 2, S378 - 83
Nitric oxide production in peritoneal macrophages from peritoneal dialysis patients with bacterial peritonitis; Plum J et al.; Nitric oxide (NO) is produced by various cell types, and it is an important mediator in many biological processes, including macrophage-mediated cellular host defense . The relevance and amount of NO production in peritonitis during peritoneal dialysis (PD) treatment is still not clear . We studied whether human peritoneal macrophages (PMphi) isolated from healthy PD patients or PD patients with peritonitis showed different spontaneous or lipopolysaccharide (LPS)/interferon gamma (IFN-gamma)-induced NO production (LPS, 1 ng/mL-10 microg/mL; IFN-gamma, 10-1000 U/mL; incubation between 6-48 hours; measured by Griess reagent) . Results were compared with human blood monocytes (HBM) isolated from buffy coats . Inducible nitric oxide synthetase (iNOS) mRNA expression was looked for in PMphi by reverse transcriptase polymerase chain reaction (RT-PCR) . Furthermore, plasma (P) and peritoneal dialysate effluent (D) nitrite concentrations were measured in vivo . The dialysate-to-plasma ratio (D/P) of nitrite concentration was inverse in the case of peritonitis compared to infection-free patients (peritonitis D/P = 1.3, non peritonitis D/P = 0.4; p < 0.01) . PMphi from peritonitis patients produced higher amounts of NO than did those from infection-free patients (0.040+/-0.044 nmol per microgram cell protein versus 0.018+/-0.015 nmol per microgram cell protein, p < 0.05) . NO release could not be further enhanced by stimulation with LPS plus IFN-gamma (1 ng/mL, 250 U/mL, respectively) . However, NO production in PMphi from infection-free patients increased during in vitro stimulation (0.044+/-0.031 nmol per microgram cell protein versus 0.018+/-0.015 nmol per microgram cell protein, p < 0.01) . An increase of iNOS mRNA expression could be demonstrated by RT-PCR . Blood monocytes from healthy donors also increased NO release during cytokine stimulation (0.032+/-0.015 nmol per microgram cell protein versus 0.019+/-0.009 nmol per microgram cell protein, p < 0.05) . Our results indicate that significant amounts of NO are released intraperitoneally in the case of bacterial peritonitis . PMphi represent a site of NO production, though the absolute amounts released in vitro are only moderate . NO production can be induced in PMphi and HBM by LPS/IFN-gamma stimulation in vitro.

J Biotechnol, 1999 Jun 11, 72(1-2), 1 - 12
A bacterial single-chain Fv antibody fragment that inhibits binding of its parental anti-E-selectin monoclonal antibody to activated human endothelial cells; Casalvilla R et al.; Using the polymerase chain reaction, we cloned, modified, and linked antibody variable (V) region coding genes from a mouse hybridoma, and produced a bacterial single-chain Fv (scFv) antibody fragment specific for E-Selectin . A vector of pBR322 origin, bearing the tryptophan promoter and the ompA bacterial signal peptide, was used to direct scFv expression to periplasm . The vector included a six-histidine coding sequence 5' to the scFv for the purification of the expressed protein using immobilized metal affinity chromatography (IMAC) . We found that the VH-Linker-VL 32-33 kDa scFv remained insoluble after cellular fractionation, and transmission electron microscopy showed the new protein to be present in the periplasm as inclusion bodies . The scFv was solubilized using urea, purified using IMAC, and renatured to its active form . In a competitive enzyme-linked immunosorbent assay with activated human vein endothelial cells in the solid phase, the scFv competed for binding with the original monoclonal antibody.

Genome Res, 1999 Jun, 9(6), 568 - 74
The CMT2D locus: refined genetic position and construction of a bacterial clone-based physical map; Ellsworth RE et al.; Charcot-Marie-Tooth (CMT) disease is a progressive neuropathy of the peripheral nervous system, typically characterized by muscle weakness of the distal limbs . CMT is noted for its genetic heterogeneity, with four distinct loci already identified for the axonal form of the disease (CMT2) . In 1996, linkage analysis of a single large family revealed the presence of a CMT2 locus on chromosome 7p14 (designated CMT2D) . Additional families have been linked subsequently to the same genomic region, including one with distal spinal muscular atrophy (dSMA) and one with mixed features of dSMA and CMT2; symptoms in both of these latter families closely resemble those seen in the original CMT2D family . There is thus a distinct possibility that CMT2 and dSMA encountered in these families reflect allelic heterogeneity at a single chromosome 7 locus . In the study reported here, we have performed more detailed linkage analysis of the original CMT2D family based on new knowledge of the physical locations of various genetic markers . The region containing the CMT2D gene, as defined by the original family, overlaps with those defined by at least two other families with CMT2 and/or dSMA symptoms . Both yeast artificial chromosome (YAC) and bacterial clone-based {bacterial artificial chromosome (BAC) and P1-derived artificial chromosome (PAC)} contig maps spanning approximately 3.4 Mb have been assembled across the combined CMT2D critical region, with the latter providing suitable clones for systematic sequencing of the interval . Preliminary analyses have already revealed at least 28 candidate genes and expressed-sequence tags (ESTs) . The mapping information reported here in conjunction with the evolving sequence data should expedite the identification of the CMT2D/dSMA gene or genes.

J Biol Chem, 1999 Jul 16, 274(29), 20438 - 43
The bacterial magnesium transporter CorA can functionally substitute for its putative homologue Mrs2p in the yeast inner mitochondrial membrane; Bui DM et al.; The yeast nuclear gene MRS2 encodes a protein of 54 kDa, the presence of which has been shown to be essential for the splicing of group II intron RNA in mitochondria and, independently, for the maintenance of a functional respiratory system . Here we show that the MRS2 gene product (Mrs2p) is an integral protein of the inner mitochondrial membrane . It appears to be inserted into this membrane by virtue of two neighboring membrane spanning domains in its carboxyl-terminal half . A large amino-terminal and a shorter carboxyl-terminal part are likely to be exposed to the matrix space . Structural features and a short sequence motif indicate that Mrs2p may be related to the bacterial CorA Mg2+ transporter . In fact, overexpression of the CorA gene in yeast partially suppresses the pet- phenotype of an mrs2 disrupted yeast strain . Disruption of the MRS2 gene leads to a significant decrease in total magnesium content of mitochondria which is compensated for by the overexpression of the CorA gene . Mutants lacking or overproducing Mrs2p exhibit phenotypes consistent with the involvement of Mrs2p in mitochondrial Mg2+ homeostasis.

IMA J Math Appl Med Biol, 1999 Jun, 16(2), 155 - 70
The use of dummy data points when fitting bacterial growth curves; Kelly LA et al.; We consider the problem of fitting mathematical models for bacterial growth and decline to experimental data . Using models which represent the phases of the growth and decline cycle in a piecewise manner, we describe how least-squares fitting can lead to potentially misleading parameter estimates . We show how these difficulties can be overcome by extending a data set to include hypothetical observations (dummy data points) which reflect biological beliefs, and the resulting stabilization of parameter estimates is analysed mathematically . The techniques are illustrated using real and simulated data sets.

Immunol Rev, 1999 Apr, 168, 257 - 69
Understanding the mechanism of action of bacterial superantigens from a decade of research; Lavoie PM et al.; In the face of the unique diversity and plasticity of the immune system pathogenic organisms have developed multiple mechanisms in adaptation to their hosts, including the expression of a particular class of molecules called superantigens . Bacterial superantigens are the most potent stimulators of T cells . The functional consequences of the expression of superantigens by bacteria can be extended not only to T lymphocytes, but also to B lymphocytes and to cells of the myeloid compartment, including antigen-presenting cells and phagocytes . The biological effects of bacterial superantigens as well as their molecular aspects have now been studied for a decade . Although there is still a long way to go to clearly understand the role these molecules play in the establishment of disease, recently acquired knowledge of their biochemistry now offers unique experimental opportunities in defining the molecular rules of T-cell activation . Here, we present some of the most recent functional and molecular aspects of the interaction of bacterial superantigens with MHC class II molecules and the T-cell receptor.

Arch Microbiol, 1999 Jul, 172(1), 51 - 8
Characterization of the interaction of dinitrogenase reductase-activating glycohydrolase from Rhodospirillum rubrum with bacterial membranes; Halbleib CM et al.; The interaction of dinitrogenase reductase-activating glycohydrolase (DRAG) with bacterial membranes and the solubilization of DRAG in response to nucleotides were characterized . Purified DRAG from Rhodospirillum rubrum reversibly bound bacterial pellet fractions from Rsp . rubrum and other nitrogen-fixing bacteria . DRAG saturated the membrane fraction of Rsp . rubrum at a concentration of 0.2 mol DRAG/mol bacteriochlorophyll, suggesting that the DRAG-binding species is prevalent in the membrane . DRAG bound poorly to phospholipid vesicles, suggesting a protein requirement for DRAG interaction with the membrane . Guanosine and uridine tri- and di-nucleotides specifically dissociated DRAG from the pellet fractions of Rsp . rubrum and Azotobacter vinelandii, while adenosine nucleotides had no dissociative effect . Guanosine 5'-triphosphate dissociated DRAG from the membrane at a concentration causing 50% dissociation (EC50) of 5.0 +/- 0.5 mM; guanosine disphosphate had an EC50 of 15.0 +/- 2.0 mM . We propose that GTP is a potential participant in the regulation of DRAG, possibly controlling the extent of DRAG association with the membrane.Keywords Rhodospirillum rubrum . Membrane . association . Nitrogenase regulation . Nucleotide bindingcom/link/service/journals/00203/bibs/172n1p51.html

Proteins, 1999 Aug 1, 36(2), 238 - 48
A new subfamily of short bacterial adenylate kinases with the Mycobacterium tuberculosis enzyme as a model: A predictive and experimental study; Munier-Lehmann H et al.; The adk gene from Mycobacterium tuberculosis codes for an enzyme of 181 amino acids . A sequence comparison with 52 different forms of adenylate kinases (AK) suggests that the enzyme from M . tuberculosis belongs to a new subfamily of "short" bacterial AKs . The recombinant protein, overexpressed in Escherichia coli, exhibits a low catalytic activity and an unexpectedly high thermal stability (Tm = 64.8 degrees C) . Based on various spectroscopic data, on the known three-dimensional structure of the AK from E . coli and on secondary structure predictions for various sequenced AKs, we propose a structural model for AK from M . tuberculosis (AKmt) . Proteins 1999;36:238-248 .

Curr Opin Neurobiol, 1999 Jun, 9(3), 267 - 73
The bacterial K+ channel structure and its implications for neuronal channels; Yellen G; Voltage-gated K+ (Kv) channels play a central role in generating action potentials and rhythmic patterns, as well as in dendritic signal processing in neurons . Recently, the first structure of a member of the K+ channel family was solved . Although this channel is from bacteria and has a streamlined body plan with no voltage gating, it establishes the architecture of the functional core of the voltage-gated (K+) channels and their relatives . This architecture explains the crucial features of ion permeation and blockade, and gives some strong hints about gating . The bacterial K+ channel structure is the central piece in a puzzle; it remains to be seen how it will fit together with other domains of the Kv channels, with auxiliary subunits, and with other signal transduction molecules.

Curr Biol, 1999 Jul 1, 9(13), R493 - 6
Bacterial cells: The migrating kinase and the master regulator; Stephens C; It is becoming clear that, as in eukaryotes, proteins in bacterial cells are targeted to specific cellular locations . The most recently discovered example is a remarkable histidine kinase that oscillates between polar and global distributions while temporally regulating transcription and DNA replication in Caulobacter.

Curr Biol, 1999 Jul 1, 9(13), R485 - 6
Bacterial evolution: Jittery genomes; Ochman H; Recent studies of long-term experimental populations of bacteria have revealed the actual progression of evolutionary change and how rates of phenotypic evolution can be decoupled from rates of genomic evolution.

Biomaterials, 1999 Jul, 20(13), 1229 - 35
Preventing bacterial adhesion onto surfaces: the low-surface-energy approach; Tsibouklis J et al.; Good-quality coatings prepared from poly(methylpropenoxyfluoroalkylsiloxane)s or poly(perfluoroacrylate)s are capable of inhibiting the bacterial colonisation of surfaces.

Mol Gen Genet, 1999 Jun, 261(4-5), 698 - 706
Construction and characterization of bacterial artificial chromosome libraries from the silkworm, Bombyx mori; Wu C et al.; Two bacterial artificial chromosome (BAC) libraries were constructed using nuclear DNA from posterior silkglands of the silkworm (Bombyx mori) strains p50 and C108 . The libraries contain a total of 36,864 clones, or approximately 9 genome equivalents . The average insert sizes in the libraries were 134.5 kb and 120.8 kb, respectively . PCR-based screening was performed on the p50 library using probes for 34 sequence-tagged sites (STSs) . Between 3 and 11 (6.1 hits on average) clones were isolated with each STS, in good agreement with the library size, 5.8 genome equivalents . The previously reported close linkage between the Bombyx homologs of the invected (Bm in) and engrailed (Bm en) genes was confirmed by construction of a BAC contig that contained both . Moreover, screening revealed novel information about the chromosomal organization of the sericin-1 and DH-PBAN genes, which were localized within a 22-kb interval and are divergently oriented . These results show that it is possible to construct contigs and analyze chromosome organization using these libraries.

EDTNA ERCA J, 1998 Jul-Sep, 24(3), 40 - 2, 44
Bacterial growth prevention in liquid bicarbonate concentrate; Stragier A et al.; We describe an original Liquid Bicarbonate Concentrate (LBC) production and distribution unit, now functioning for five years . To prevent bacterial growth several measures were taken: LBC osmolarity as high as possible, fast concentrate turnover, UV irradiation of the tank and continuous circulation of LBC . Although, six and ten months elapsed before the first two positive cultures appeared after implementation of the new distribution circuit, subsequently, the interval between positive cultures became much shorter so that disinfection of the LBC unit is now required every 3 weeks . Changing the disinfecting agent from hypochlorite to peracetic acid did not succeed in increasing this interval . Our experience draws special the attention to the problem of bacterial growth in an on-line LBC production and distribution unit and defines the potential methods to control it . Continuous vigilance remains mandatory.

EMBO J, 1999 Jul 1, 18(13), 3736 - 45
A fork junction DNA-protein switch that controls promoter melting by the bacterial enhancer-dependent sigma factor; Guo Y et al.; Results of binding assays using DNA fork junction probes indicate that sigma 54 contains multiple determinants that regulate melting to allow RNA polymerase to remain in closed promoter complexes in order to respond to enhancers . Gel mobility shift studies indicate that the -12 promoter element and parts of sigma 54 act together to form a molecular switch that controls melting . The DNA sequences and the sigma 54 N-terminus help direct polymerase to the location within the -12 promoter element where melting will initiate . However, the fork junction that would lead to melting does not form, due to the action of an inhibitory DNA element . Such unregulated melting is inhibited further by the lack of availability of the single-strand binding elements, which are needed to spread opening from the junction to the transcription start site . Thus, in the absence of looping enhancer protein, proper regulation is maintained as the sigma 54 polymerase remains bound in an inactive state . These complex protein-DNA interactions allow the controls over protein recruitment and DNA melting to be separated, enhancing the diversity of accessible mechanisms of transcription regulation.

Clin Diagn Lab Immunol, 1999 Jul, 6(4), 534 - 6
Outcomes of Bordetella infections in vaccinated children: effects of bacterial number in the nasopharynx and patient age; He Q et al.; Five outbreaks of infection (three pertussis, one parapertussis, and one mixed) in schools were studied prospectively . Nasopharyngeal swabs were obtained from a total of 697 children for culture of Bordetella organisms . Of 50 vaccinated children with culture-confirmed Bordetella infections (29 with pertussis and 21 parapertussis), 40 were symptomatic and 10 remained symptom-free . Smaller numbers of colonies were recovered from the nasopharyngeal swabs of the asymptomatic children than from those of the symptomatic children . Older children had longer durations of illness than younger ones . Our results indicate that during outbreaks children who do not develop disease may have small amounts of Bordetella organisms in their nasopharynges and/or better immune defenses against the disease.

Biol Bull, 1999 Jun, 196(3), 273 - 80
Identification of sibling species of the bryozoan Bugula neritina that produce different anticancer bryostatins and harbor distinct strains of the bacterial symbiont "Candidatus Endobugula sertula"; Davidson SK et al.; Although the cosmopolitan marine bryozoan Bugula neritina is recognized as a single species, natural products from this bryozoan vary among populations . B . neritina is the source of the anticancer drug candidate bryostatin 1, but it also produces other bryostatins, and different populations contain different bryostatins . We defined two chemotypes on the basis of previous studies: chemotype O contains bryostatins with an octa-2,4-dienoate substituent (including bryostatin 1), as well as other bryostatins; chemotype M lacks bryostatins with the octa-2,4-dienoate substituent . B . neritina contains a symbiotic gamma-proteobacterium "Candidatus Endobugula sertula," and it has been proposed that bryostatins may be synthesized by bacterial symbionts . In this study, B . neritina populations along the California coast were sampled for genetic variation and bryostatin content . Colonies that differ in chemotype also differ genetically by 8% in the mitochondrial cytochrome c oxidase subunit 1 (CO I) gene; this difference is sufficient to suggest that the chemotypes represent different species . Each species contains a distinct strain of "E . sertula" that differs at four nucleotide sites in the small subunit ribosomal RNA (SSU rRNA) gene . These results indicate that the chemotypes have a genetic basis rather than an environmental cause . Gene sequences from an Atlantic sample matched sequences from the California chemotype M colonies, suggesting that this type may be cosmopolitan due to transport on boat hulls.

World J Surg, 1999 Jul, 23(7), 625 - 8; discussion 629
Experimental study of the effect of different meshes on bacterial translocation; Baykal A et al.; Implantation of intraabdominal biomaterials promotes bacterial translocation (BT) . In this study we planned to determine the effect of different types of mesh on the induction of BT . Swiss albino mice were divided into four groups: control, polypropylene (PP), polyglactin 910 (PG), and dura mater (DM) . At hour 0, an abdominal wall defect was created in all animals . In the control group the defect was closed primarily . PP, PG, and DM meshes were used to repair the defects such that the intestines were in contact with the mesh in the remaining three groups . BT was evaluated 4, 24, and 48 hours later . At 4 hours total BT increased in the PP group compared with that in the control (p = 0.0321) and DM (p = 0.0098) groups . At 24 hours the PG group had increased BT compared with the controls (p = 0.0392) and the DM group (p = 0.0274), whereas the PP group had increased BT compared with the DM group only (p = 0.0477) . At 48 hours both PG and PP groups had increased BT compared with controls (p = 0.0431 and p = 0.0001, respectively); the PP group had also increased BT compared to the DM group (p = 0.001) and the PG group (p = 0.017) . In the control, DM, and PP groups there was no intragroup statistical difference . In the PG group there was a significant increase in BT at 24 hours compared to that at 4 hours (p = 0.0274) . Prosthetic meshes led to increased BT compared to that with the DM mesh . This effect might be attributed to the different organic and physical properties of the meshes.

Acta Pharm Hung, 1999 Apr, 69(2), 69 - 71
{Effect of immunosuppressive agents and antilymphocyte serum on bacterial translocation in mice}; Anderlik P et al.; Following intraperitoneally applied treatment with 0.5 ml of ana partes diluted antilymphocyte serum (ALS) of immunosuppressive effect no bacterial translocation (BT) was observed in mice . The ALS treatment applied in combination with other immunosuppressive agents such as lymphotropic cytostatics as dianhydrogalactitol (30 mg/kg) or chlorpromazine (75 mg/kg) did not increase the mice drug sensitivity to used agents . According to our results, ALS can be suitable for combined application with other immunosuppressive agents as it can increase immunosuppression without side-effects such as those induced by bacterial translocation.

Lett Appl Microbiol, 1999 Jun, 28(6), 445 - 7
An easy colorimetric assay for screening and qualitative assessment of deiodination and dehalogenation by bacterial cultures; Kuritz T; Halogenated organic substances are among the main environmental concerns . A number of micro-organisms are able to dehalogenate these compounds . However, the methods for the assessment of micro-organismal ability to dehalogenate are expensive and require complex instrumentation . Here, an easy colorimetric assay for the screening and assessment of the ability of bacterial cultures to deiodinate, and potentially dehalogenate, chemical substances is proposed . The method is based on the oxidation of iodide, released due to biotransformation, to iodine followed by a subsequent detection of iodine by a classical reaction with starch.

Biochemistry, 1999 Jun 29, 38(26), 8253 - 70
Calculated protein and proton motions coupled to electron transfer: electron transfer from QA- to QB in bacterial photosynthetic reaction centers; Alexov EG et al.; Reaction centers from Rhodobacter sphaeroides were subjected to Monte Carlo sampling to determine the Boltzmann distribution of side-chain ionization states and positions and buried water orientation and site occupancy . Changing the oxidation states of the bacteriochlorophyll dimer electron donor (P) and primary (QA) and secondary (QB) quinone electron acceptors allows preparation of the ground (all neutral), P+QA-, P+QB-, P0QA-, and P0QB- states . The calculated proton binding going from ground to other oxidation states and the free energy of electron transfer from QA-QB to form QAQB- (DeltaGAB) compare well with experiment from pH 5 to pH 11 . At pH 7 DeltaGAB is measured as -65 meV and calculated to be -80 meV . With fixed protein positions as in standard electrostatic calculations, DeltaGAB is +170 meV . At pH 7 approximately 0.2 H+/protein is bound on QA reduction . On electron transfer to QB there is little additional proton uptake, but shifts in side chain protonation and position occur throughout the protein . Waters in channels leading from QB to the surface change site occupancy and orientation . A cluster of acids (GluL212, AspL210, and L213) and SerL223 near QB play important roles . A simplified view shows this cluster with a single negative charge (on AspL213 with a hydrogen bond to SerL233) in the ground state . In the QB- state the cluster still has one negative charge, now on the more distant AspL210 . AspL213 and SerL223 move so SerL223 can hydrogen bond to QB- . These rearrangements plus other changes throughout the protein make the reaction energetically favorable.

Protein Sci, 1999 Jun, 8(6), 1342 - 9
The crystal structure of a bacterial, bifunctional 5,10 methylene-tetrahydrofolate dehydrogenase/cyclohydrolase; Shen BW et al.; The structure of a bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase/cyclohydrolase from Escherichia coli has been determined at 2.5 A resolution in the absence of bound substrates and compared to the NADP-bound structure of the homologous enzyme domains from a trifunctional human synthetase enzyme . Superposition of these structures allows the identification of a highly conserved cluster of basic residues that are appropriately positioned to serve as a binding site for the poly-gamma-glutamyl tail of the tetrahydrofolate substrate . Modeling studies and molecular dynamic simulations of bound methylene-tetrahydrofolate and NADP shows that this binding site would allow interaction of the nicotinamide and pterin rings in the dehydrogenase active site . Comparison of these enzymes also indicates differences between their active sites that might allow the development of inhibitors specific to the bacterial target.

Carbohydr Res, 1999 Jan 31, 315(1-2), 137 - 41
Enzymatic synthesis of Kdn oligosaccharides by a bacterial alpha-(2-->6)-sialyltransferase; Kajihara Y et al.; Synthesis of CMP-deaminoneuraminic acid (CMP-beta-D-Kdn) and its enzymatic transfer reaction using bacterial alpha-(2-->6)-sialyltransferase were examined . CMP-beta-D-Kdn was prepared from methyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-D-glycero-beta-D-galacto-2- nonulopyranosonate (2) in 24% overall yield . Enzymatic synthesis of Kdn oligosaccharide with CMP-beta-D-Kdn (10.2 mumol), methyl beta-D-lactosaminide (7, 8.1 mumol) and purified sialyltransferase (80 munits) afforded Kdn-alpha-(2-->6)-Gal-beta-(1-->4)-GlcNAc-beta-1-OMe in 77% yield.

Hepatology, 1999 Jul, 30(1), 128 - 36
Hepatic regulation of platelet-activating factor acetylhydrolase and lecithin:cholesterol acyltransferase biliary and plasma output in rats exposed to bacterial lipopolysaccharide; Svetlov SI et al.; Normal rat bile contains secretory platelet-activating factor acetylhydrolase (PAF-AH), the enzyme capable of hydrolyzing the inflammatory mediator platelet-activating factor (PAF), and phospholipids containing oxidized truncated fatty acids . Because lecithin:cholesterol acyltransferase (LCAT) possesses intrinsic PAF-AH-like activity, it also may represent a potential anti-inflammatory enzyme . The behavior of PAF-AH and LCAT in hepatobiliary inflammatory responses in vivo has not been characterized . We therefore investigated the biliary and plasma secretion and pharmacological characteristics of these enzymes in rats subjected to intraportal bacterial endotoxin exposure (lipopolysaccharide {LPS}, Escherichia coli, 055:B5) . Portal vein LPS infusion (1 mg/kg, bolus) resulted in a maximal 4- to 5-fold increase in bile PAF-AH-specific activity with a gradual decline to baseline by 18 hours . Biliary PAF-AH hydrolyzed also the truncated sn-2-succinoyl and sn-2-glutaroyl analogs of PAF, indicating a broader activity of PAF-AH in bile toward byproducts of glycerophospholipid peroxidation . Plasma PAF-AH activity was not altered 5 hours after LPS injection compared with saline injection, but it was significantly elevated 18 hours after endotoxin exposure . The levels of LCAT in bile were low and declined to nearly undetectable values by 5 hours after cannulation in both control and LPS-exposed rats . Plasma LCAT activity was significantly increased after 5 hours and decreased 18 hours after LPS injection . In summary, hepatic exposure to endotoxin results in a rapid increase in biliary secretion of PAF-AH followed by elevation of LCAT and PAF-AH levels in plasma . We propose that biliary secretion of PAF-AH may be involved in the hepatic response to endotoxic insult by counteracting potential inflammatory damage in the biliary tree and gastrointestinal tract, whereas plasma increases in LCAT and PAF-AH may promote elimination of excess PAF and oxidized phospholipids in the circulation.

J Biomater Sci Polym Ed, 1999, 10(6), 679 - 97
Bacterial adhesion to functionalized polyurethanes; Flemming RG et al.; The effect of fibrinogen and high molecular weight kininogen on bacterial adhesion to functionalized polyurethanes was studied . Glass slides were coated with different polyurethanes, including Pellethane, sulfonated Pellethane, phosphonated Pellethane, a zwitterionic phosphonated polyurethane, and quaternized amine polyurethanes . The polymer-coated glass squares were exposed to radiolabelled S . aureus . When comparing adhesion to bare polyurethanes, it was found that adhesion was lowest on the phosphonated Pellethane and the zwitterionic phosphonated polyurethane while highest on the methyl quaternized polyurethanes . Fibrinogen-mediated adhesion was studied by first exposing the polymers to increasing concentrations of canine fibrinogen before incubating them with S . aureus . All the polymers except the quaternized amine polyurethanes exhibited at least ten-fold increases in bacterial adhesion as the fibrinogen treatment concentration was increased from 0.0 to 10.0 microg ml(-1) . The quaternized amine polyurethanes maintained their relatively high amount of bacterial adhesion regardless of the fibrinogen concentration . The effect of two-chain high molecular weight kininogen (TCHMWK) on fibrinogen-mediated bacterial adhesion was assessed by exposing the polymers to 1.0 microg ml(-1) fibrinogen followed by two different concentrations of TCHMWK . Decreases in bacterial adhesion were observed on all the polymers except the quaternized amine polyurethanes, which again retained their relatively high amount of bacterial adhesion.

J Immunol, 1999 Jul 1, 163(1), 224 - 31
Bacterial DNA or oligonucleotides containing unmethylated CpG motifs can minimize lipopolysaccharide-induced inflammation in the lower respiratory tract through an IL-12-dependent pathway; Schwartz DA et al.; To determine whether the systemic immune activation by CpG DNA could alter airway inflammation, we pretreated mice with either i.v . bacterial DNA (bDNA) or oligonucleotides with or without CpG motifs, exposed these mice to LPS by inhalation, and measured the inflammatory response systemically and in the lung immediately following LPS inhalation . Compared with non-CpG oligonucleotides, i . v . treatment with CpG oligonucleotides resulted in higher systemic concentrations of polymorphonuclear leukocytes, IL-10, and IL-12, but significantly reduced the concentration of total cells, polymorphonuclear leukocytes, TNF-alpha, and macrophage inflammatory protein-2 in the lavage fluid following LPS inhalation . The immunoprotective effect of CpG-containing oligonucleotides was dose-dependent and was most pronounced in mice pretreated between 2 and 4 h before the inhalation challenge, corresponding to the peak levels of serum cytokines . bDNA resulted in a similar immunoprotective effect, and methylation of the CpG motifs abolished the protective effect of CpG oligonucleotides . The protective effect of CpG oligonucleotides was observed in mice with either a disrupted IL-10 or IFN-gamma gene, but release of cytokines in the lung was increased, especially in the mice lacking IFN-gamma . In contrast, CpG DNA did not protect mice with a disrupted IL-12 gene against the LPS-induced cellular influx, even though CpG DNA reduced the release of TNF-alpha and macrophage inflammatory protein-2 in the lung . These findings indicate that CpG-containing oligonucleotides or bDNA are protected against LPS-induced cellular airway inflammation through an IL-12-dependent pathway, and that the pulmonary cytokine and cellular changes appear to be regulated independently.

Curr Opin Microbiol, 1999 Jun, 2(3), 312 - 6
Multilocus sequence typing: molecular typing of bacterial pathogens in an era of rapid DNA sequencing and the internet; Spratt BG; Multilocus sequence typing is a development of multilocus enzyme electrophoresis in which the alleles at multiple house-keeping loci are assigned directly by nucleotide sequencing, rather than indirectly from the electrophoretic mobilities of their gene products . A major advantage of this approach is that sequence data are unambiguous and electronically portable, allowing molecular typing of bacterial pathogens (or other infectious agents) via the Internet.

Clin Transplant, 1999 Jun, 13(3), 260 - 5
Impact of solid organ transplantation and immunosuppression on fever, leukocytosis, and physiologic response during bacterial and fungal infections; Sawyer RG et al.; Immunosuppressed solid organ transplant patients may exhibit a blunted response to infection compared to non-transplant patients . To test this hypothesis, we prospectively identified all episodes of bacterial and fungal infection on the in-patient abdominal organ transplant service in our hospital, in 1997, and compared them to infected general surgery and trauma admissions treated simultaneously on the same wards . Eighty-two infections occurred in transplant patients versus 463 in non-transplant patients . Transplant patients demonstrated an overall greater physiologic response {Acute Physiology and Chronic Health Evaluation (APACHE II) and Acute Physiology Scores (APS) at the time of infection of 17.0+/-0.7 and 10.3+/-0.6, respectively, vs . 12.2+/-0.4 and 8.0+/-0.3 for non-transplant patients, p < 0.003}, with a similar maximum temperature (38.0+/-0.1 vs . 38.2+/-0.1 degrees C, p = 0.2) and white blood cell (WBC) count (12.1+/-1.0 vs . 13.9+/-0.4 k/mL, p = 0.08) . Upon further analysis of subgroups, patients receiving mycophenolate or azathioprine had significantly lower maximum temperatures (37.9+/-0.2 degrees C) and WBC counts (11.0+/-0.9 k/mL) when compared to non-transplant patients, while steroids appeared to have little effect on the systemic inflammatory response . Overall mortality was similar between groups . In general, solid organ transplant recipients exhibit a physiologic response to bacterial or fungal infection (as measured by the APS) at least as great as that seen in non-transplant surgical patients, although mycophenolate and azathioprine appear to slightly depress the ability to respond with fever and leukocytosis . None of these differences appeared to affect overall mortality.

Cell, 1999 Jun 11, 97(6), 755 - 65
Polypeptide flux through bacterial Hsp70: DnaK cooperates with trigger factor in chaperoning nascent chains; Teter SA et al.; A role for DnaK, the major E . coli Hsp70, in chaperoning de novo protein folding has remained elusive . Here we show that under nonstress conditions DnaK transiently associates with a wide variety of nascent and newly synthesized polypeptides, with a preference for chains larger than 30 kDa . Deletion of the nonessential gene encoding trigger factor, a ribosome-associated chaperone, results in a doubling of the fraction of nascent polypeptides interacting with DnaK . Combined deletion of the trigger factor and DnaK genes is lethal under normal growth conditions . These findings indicate important, partially overlapping functions of DnaK and trigger factor in de novo protein folding and explain why the loss of either chaperone can be tolerated by E . coli.

J Neuroimmunol, 1999 Jan 1, 93(1-2), 122 - 5
Fas (APO-1/CD95) in inflammatory CNS diseases: intrathecal release in bacterial meningitis; Fassbender K et al.; Release of Fas (APO-1, CD95), a type L-membrane protein which plays a crucial role in cytokine-mediated apoptosis was investigated in bacterial meningitis, viral meningoencephalitis and multiple sclerosis in vivo . After correction for bloodbrain-CSF-disruption, significantly increased intrathecal release of Fas was demonstrated exclusively in bacterial meningitis arguing for an apoptotic cell death of granulocytes in the subarachnoidal space aimed to self-limit inflammatory host response.

Proc Natl Acad Sci U S A, 1999 Jun 22, 96(13), 7398 - 402
Stimulation of homologous recombination in plants by expression of the bacterial resolvase ruvC
Shalev G, Sitrit Y, Avivi-Ragolski N, Lichtenstein C, Levy AA.
Targeted gene disruption exploits homologous recombination (HR) as a powerful reverse genetic tool, for example, in bacteria, yeast, and transgenic knockout mice, but it has not been applied to plants, owing to the low frequency of HR and the lack of recombinogenic mutants . To increase the frequency of HR in plants, we constructed transgenic tobacco lines carrying the Escherichia coli RuvC gene fused to a plant viral nuclear localization signal . We show that RuvC, encoding an endonuclease that binds to and resolves recombination intermediates (Holliday junctions) is properly transcribed in these lines and stimulates HR . We observed a 12-fold stimulation of somatic crossover between genomic sequences, a 11-fold stimulation of intrachromosomal recombination, and a 56-fold increase for the frequency of extrachromosomal recombination between plasmids cotransformed into young leaves via particle bombardment . This stimulating effect may be transferred to any plant species to obtain recombinogenic plants and thus constitutes an important step toward gene targeting.

Vestn Oftalmol, 1999 Mar-Apr, 115(2), 31 - 2
{Clinical assessment of infrasonic phonophoresis efficacy in the treatment of bacterial keratitis}; Sidorenko EI et al.; Therapeutic efficacy of infrasonic phonophoresis is studied in 30 patients with bacterial keratitis . Control group consisted of 87 patients with the same diagnosis . Clinical studies included comparative evaluation of the therapeutic efficacy of infrasonic phonophoresis and traditional local instillations of the same drugs . Before treatment, visual acuity was the same in both groups, while after regression of inflammation after treatment it was 0.13 higher in the phonophoresis group . Results of clinical studies indicate a higher efficacy of infrasonic therapy of patients with keratitis . The duration of therapy was decreased, number of bed-days decreased, and visual acuity after treatment improved.

Infect Immun, 1999 Jul, 67(7), 3637 - 40
Enhanced in vivo immune responses to bacterial lipopolysaccharide by exogenous CD40 stimulation; Barr TA et al.; The lack of specific T-cell help in immune responses to thymus-independent antigens results in weak, predominantly immunoglobulin M-mediated immunity with little or no memory . In the work presented here we show how the exogenous stimulation of CD40 by monoclonal antibodies can mimic T-cell help, resulting in enhanced immune responses which are protective against bacterial infection.

J Mol Biol, 1999 Jun 25, 289(5), 1253 - 65
Filamentous phage are released from the bacterial membrane by a two-step mechanism involving a short C-terminal fragment of pIII; Rakonjac J et al.; Filamentous phage assemble at the membrane of infected cells . The phage filament is released from the membrane at the end of assembly, after four to five copies of the minor proteins, pIII and pVI, have been added to the end of the virion . In the absence of pIII or pVI, phage filaments are not released, but remain associated with the cells . The C-terminal portion of pIII, termed the "C" domain, is required for the release of stable virions.With the use of pIII C-terminal fragments of increasing size, termination of assembly can be divided into various steps . An 83-residue fragment leads to the incorporation of pVI into the assembling phage, but does not release it from the membrane . A slightly longer fragment (93 residues) is sufficient to release the particle into the culture supernatant . However, these released particles are unstable in the detergent, sarkosyl, which does not disrupt wild-type phage . A fragment of >121 residues is needed for the particle to become detergent resistant . Thus, the C-domain can be divided into two subdomains: C2, sufficient for release, and C1, required for virion stability.A model for termination of phage assembly is proposed in which pIII and pVI dock to the membrane-associated filament and form a pre- termination complex . Then, a conformational change involving the C2 domain of pIII disrupts the hydrophobic interactions with the inner membrane, releasing the phage from the cells . The pIII-mediated release of phage from the membranes points to one possible mechanism for excision of membrane-anchored protein complexes from lipid bilayers .

Genomics, 1999 Jun 15, 58(3), 250 - 3
A modular, positive selection bacterial artificial chromosome vector with multiple cloning sites; Frengen E et al.; To construct large-insert libraries for the sequencing, mapping, and functional studies of complex genomes, we have constructed a new modular bacterial artificial chromosome (BAC) vector, pBACe3.6 (GenBank Accession No . U80929) . This vector contains multiple cloning sites located within the sacB gene, allowing positive selection for recombinant clones on sucrose-containing medium . A recognition site for the PI-SceI nuclease has also been included, which permits linearization of recombinant DNA irrespective of the characteristics of the insert sequences . An attTn7 sequence present in pBACe3.6 permits retrofitting of BAC clones by Tn7-mediated insertion of desirable sequence elements into the vector portion . The ability to retrofit BAC clones will be useful for functional analysis of genes carried on the cloned inserts . The pBACe3.6 vector has been used for the construction of many genomic libraries currently serving as resources for large-scale mapping and sequencing .

J Trauma, 1999 Jun, 46(6), 1096 - 9
Experimental study of the effects of splenectomy and partial splenectomy on bacterial translocation; Baykal A et al.; BACKGROUND: The aim of this study is to evaluate the effect of splenectomy and partial splenectomy in a burn-induced bacterial translocation model and to study Kupffer cell (KC) morphology and number . METHODS: Mice were divided into sham-burn and burn groups . Each group was also subdivided to sham-splenectomy, partial-splenectomy, and splenectomy subgroups . At day 0, operations were performed . At the postoperative 10th day, a sham burn or burn injury was made in all animals . Twenty-four hours later, cultures for bacterial translocation were obtained and livers were evaluated for the quantity and morphology of KCs . RESULTS: Burned-splenectomized animals had significantly decreased bacterial translocation when compared with sham-splenectomized animals (p = 0.031) . Interestingly, in both the sham-burned and burned groups, splenectomy subgroups had significantly higher numbers of KCs compared with partial-splenectomy and sham-splenectomy subgroups (p<0.00000) . Burn injury caused a significant decrease of KC numbers in all subgroups compared with their correspondent sham-burned subgroups (p<0.05) . CONCLUSION: Results revealed that splenectomy decreases bacterial translocation and also increases the number of KCs.

FEMS Microbiol Rev, 1999 Jun, 23(3), 371 - 90
Function, mechanism and regulation of bacterial ribonucleases; Nicholson AW; The maturation and degradation of RNA molecules are essential features of the mechanism of gene expression, and provide the two main points for post-transcriptional regulation . Cells employ a functionally diverse array of nucleases to carry out RNA maturation and turnover . Viruses also employ cellular ribonucleases, or even use their own in their reproductive cycles . Studies on bacterial ribonucleases, and in particular those from Escherichia coli, are providing insight into ribonuclease structure, mechanism, and regulation . Ongoing biochemical and genetic analyses are revealing that many ribonucleases are phylogenetically conserved, and exhibit overlapping functional roles and perhaps common catalytic mechanisms . This article reviews the salient features of bacterial ribonucleases, with a focus on those of E . coli, and in particular, ribonuclease III . RNase III participates in a number of RNA maturation and RNA decay pathways, and is regulated by phosphorylation in the T7 phage-infected cell . Plasmid and phage RNAs, in addition to cellular transcripts, are RNase III targets . RNase III orthologues occur in eukaryotic cells, and play key functional roles . As such, RNase III provides an important model with which to understand mechanisms of RNA maturation, RNA decay, and gene regulation.

Pediatr Surg Int, 1999, 15(3-4), 160 - 3
Effect of growth hormone on bacterial translocation in experimental short-bowel syndrome; Eizaguirre I et al.; Despite the adaptive process triggered in the remaining intestine by massive bowel resection, bacterial translocation (BT) is frequent under these conditions . Several trophic factors, including growth hormone (GH), are involved in the process of adaptation in short-bowel syndrome (SBS) . However, the effect of GH on BT has not been investigated experimentally . The aim of this study was to test the hypothesis that GH administration prevents BT in rats with SBS receiving only parental nutrition (PN) . Nineteen adult Wistar rats underwent central venous cannulation and were randomly assigned to one of two groups receiving for 10 days two treatment regimes: PN group (n = 10): fasting, all-in-one PN solution (300 ml . kg . 24 h, 280 kcal/kg . 24 h), 80% gut section including ileocecal valve; GH group (n = 9): fasting, same PN regime and resection plus GH 1 mg/kg s.c) . At the end of the experiment, the rats were killed and mesenteric lymph nodes (MLN) and samples of systemic and portal blood were obtained and cultured . Several samples of full-thickness jejunal wall were taken for determining cell proliferation index (PCNA) and mucosal thickness . Jejunal mucosal thickness increased by 30% and PCNA index by 35% in GH-treated rats in comparison with those treated with PN alone . However, contrary to our expectations, BT expressed by positive culture of intestinal flora in portal blood, MLN, or systemic blood was found in 60% of PN and 87% of GH animals (P = 0.1) . Translocation to the general circulation expressed by the presence of organisms in systemic blood was detected in 0% of PN and 44% of GH rats (P < 0.05) . Although exogenous GH improves gut mucosal structure in rats with SBS treated with PN, it seems to increase rather than decrease mucosal permeability to intestinal bacteria.

Pediatr Surg Int, 1999, 15(3-4), 155 - 9
The effect of mucin on bacterial translocation in I-407 fetal and Caco-2 adult enterocyte cultured cell lines; Gork AS et al.; Although the intestinal mucosa forms a crucial barrier between the host and the environment, bacterial translocation (BT) occurs frequently in neonates and may be a source of sepsis . The intestinal mucous gel layer is thought to be a vital component of the gut barrier and is composed, in part, of a family of glycoproteins known as mucins . Our aim was to study the effects of mucin on BT in an enterocyte cell-culture model using a fetal (I-407) and an adult (Caco-2) intestinal cell line . I-407 and Caco-2 cells were grown to confluence on porous filters in a two-chamber Transwell system . The integrity of the monolayers was confirmed by transepithelial electrical resistance (TEER) and permeability using the macromolecule dextran blue . Cells were treated with mucin (40 mg/ml) prior to inoculation of 1 x 10(6) Escherichia coli C25 . The magnitude of BT was determined quantitatively by culturing the samples from the basal chamber of the wells and was expressed as log 10 {Colony Forming Units (CFU)/ml} . Statistical analysis was performed by the Mann-Whitney U test with statistical significance at P < 0.05 . Mucin inhibited BT across both fetal and adult cultured enterocyte monolayers; however, the inhibitory effect was less on the fetal cells compared to the adult cells . Dextran-blue studies showed that monolayers were intact throughout the experiments . Despite 98% inhibition of BT, mucin had a statistically significant effect on post-bacterial inoculation TEER in Caco-2 cells and no effect in I-407 cells . The ability of mucin, a mucous-barrier glycoprotein, to inhibit BT across immature intestinal enterocytes, as in the neonate, may be diminished compared to mature adult enterocytes.

Pediatr Surg Int, 1999, 15(3-4), 150 - 4
The effect of phospholipids and mucin on bacterial internalization in an enterocyte-cell culture model; Usui N et al.; A primary component of the intestinal mucous layer that functions as a barrier to luminal bacteria is mucin, a high-molecular-weight glucoprotein . In addition, the mucous layer also contains other important elements such as phospholipids (PLs), which may effect bacterial translocation (BTL) . It has been reported that mucin inhibits Escherichia coli translocation; however, the effect of PLs on intestinal permeability is still controversial . We have recently reported that the concentration of mucous PLs is higher in neonatal as compared to adult rabbits . The functional significance of these biochemical differences on BTL remains to be determined . The aim of this study was to evaluate the effect of PL and mucin composition on BTL in a human enterocyte-cell culture model . Human enterocyte Caco-2 cells were seeded in 24-well tissue-culture plates and grown for 14 days to confluence . The monolayers were pretreated with phosphate buffered saline as control, 10 mg/ml or 20 mg/ml mucin, 0 . 5 mM or 1.0 mM PL mixture based on neonatal (NPL) and adult (APL) composition, and 10 mg/ml mucin with 0.5 mM either APL or NPL mixtures 30 min before a 120-min incubation period at 37 degrees C with 10(8) colony forming units (CFU) of E . coli C25 . Non-internalized bacteria were killed by the addition of gentamicin . Internalized bacteria were quantified by counting CFU from enterocyte-cell lysates grown on MacConkey's agar . Mucin inhibited bacterial internalization, while both compositions of PLs promoted it . Mucin added to the PL solution also diminished the stimulatory effect of PLs on bacterial internalization . These results indicate that the increased concentration of PLs found in the intestinal mucous layer of neonates, and/or the alteration in the balance between PLs and mucin, may play a role in the increased BTL seen in neonates.

EMBO J, 1999 Jun 15, 18(12), 3271 - 81
Complementation of DsbA deficiency with secreted thioredoxin variants reveals the crucial role of an efficient dithiol oxidant for catalyzed protein folding in the bacterial periplasm; Jonda S et al.; The thiol/disulfide oxidoreductase DsbA is the strongest oxidant of the thioredoxin superfamily and is required for efficient disulfide bond formation in the periplasm of Escherichia coli . To determine the importance of the redox potential of the final oxidant in periplasmic protein folding, we have investigated the ability of the most reducing thiol/disulfide oxidoreductase, E.coli thioredoxin, of complementing DsbA deficiency when secreted to the periplasm . In addition, we secreted thioredoxin variants with increased redox potentials as well as the catalytic a-domain of human protein disulfide isomerase (PDI) to the periplasm . While secreted wild-type thioredoxin and the most reducing thioredoxin variant could not replace DsbA, all more oxidizing thioredoxin variants as well as the PDI a-domain could complement DsbA deficiency in a DsbB-dependent manner . There is an excellent agreement between the activity of the secreted thioredoxin variants in vivo and their ability to oxidize polypeptides fast and quantitatively in vitro . We conclude that the redox potential of the direct oxidant of folding proteins and in particular its reactivity towards reduced polypeptides are crucial for efficient oxidative protein folding in the bacterial periplasm.

Pediatr Res, 1999 Jun, 45(6), 871 - 6
Neutrophils from term and preterm newborn infants express the high affinity Fcgamma-receptor I (CD64) during bacterial infections; Fjaertoft G et al.; The high affinity Fcgamma-receptor I (FcgammaRI, CD64) is normally expressed only to a very low extent by neutrophils . During bacterial infections, however, neutrophils from adult patients significantly increase their expression of FcgammaRI . Stimulation through FcgammaRI is a highly effective way to improve various aspects of neutrophil function, including phagocytosis . In our study the expression of FcgammaRI on neutrophils from preterm (n = 9) and term (n = 3) newborn infants, children (n = 14), and adults (n = 6) during the early phase of an acute bacterial infection was investigated . Our results showed that neutrophils from newborn infants with bacterial infection expressed FcgammaRI to a significantly higher extent than both noninfected preterm (p < 0.001) and term (p < 0.001) newborn infants and that neutrophils from preterm neonates expressed FcgammaRI to the same extent as neutrophils from term neonates and older infants, children, and adults . No difference in the neutrophil cell surface expression of FcgammaRI during bacterial infections was found among newborn infants, children, and adults . Expression of FcgammaRI probably represents an important mechanism to improve neutrophil phagocytosis as well as other aspects of neutrophil function during bacterial infections, especially in preterm infants . Our study indicates that measurement of cell surface expression of FcgammaRI on neutrophils could be a useful indicator of severe bacterial infections in preterm and term neonates, as well as in older children and adults.

Eur J Surg, 1999 Apr, 165(4), 378 - 82
Effect of intraperitoneal and extraperitoneal insertion of mesh on bacterial translocation: does it make a difference?
Baykal A, Gunbatili F, Aran O, Hascelik G, Korkmaz A, Sayek I.
OBJECTIVE: To asses the effect of insertion of mesh, with or without contact with the peritoneum, on the induction of bacterial translocation . DESIGN: Open experimental study . SETTING: Surgical research laboratory, Turkey . SUBJECTS: 158 Swiss albino mice . INTERVENTIONS: A defect in the abdominal wall was created . In the control group, the defect was closed primarily . In the extraperitoneal group, polypropylene mesh was sutured over the abdominal wall after primary closure of the peritoneum and in the intraperitoneal group, polypropylene mesh was sutured to close the created defect so that it was in contact with the intestines . MAIN OUTCOME MEASURES: Bacterial translocation at 4, 24 and 48 hours . RESULTS: Insertion of mesh in contact with the peritoneum led to increased bacterial translocation to mesenteric lymph nodes at 4 (p = 0.02) and 48 (p = 0.03) hours compared with insertion without contact . CONCLUSION: Contact between a foreign body and the peritoneum is required to induce bacterial translocation.

Philos Trans R Soc Lond B Biol Sci, 1999 Apr 29, 354(1384), 701 - 10
Bacterial population genetics, evolution and epidemiology; Spratt BG et al.; Asexual bacterial populations inevitably consist of an assemblage of distinct clonal lineages . However, bacterial populations are not entirely asexual since recombinational exchanges occur, mobilizing small genome segments among lineages and species . The relative contribution of recombination, as opposed to de novo mutation, in the generation of new bacterial genotypes varies among bacterial populations and, as this contribution increases, the clonality of a given population decreases . In consequence, a spectrum of possible population structures exists, with few bacterial species occupying the extremes of highly clonal and completely non-clonal, most containing both clonal and non-clonal elements . The analysis of collections of bacterial isolates, which accurately represent the natural population, by nucleotide sequence determination of multiple housekeeping loci provides data that can be used both to investigate the population structure of bacterial pathogens and for the molecular characterization of bacterial isolates . Understanding the population structure of a given pathogen is important since it impacts on the questions that can be addressed by, and the methods and samples required for, effective molecular epidemiological studies.

Biochem Biophys Res Commun, 1999 Jun 16, 259(3), 550 - 6
Regulators of G-protein signaling (RGS) 1 and 16 are induced in response to bacterial lipopolysaccharide and stimulate c-fos promoter expression; Panetta R et al.; Regulators of G-protein signaling (RGS) are negative regulators of G-protein-coupled receptor (GPCR) signaling . Sepsis is a pathophysiological condition that is induced primarily in response to bacterial infection and is associated with decreased responsiveness to a number of vasoactive GPCR agonists . Using a degenerate RT-PCR screen, we report that RGS1 and RGS16 were amplified from the heart and aorta of septic animals . By Northern blot analysis, RGS1 and RGS16 were upregulated, with their respective levels increasing 6- and 50-fold in septic hearts . Using a yeast-based bioassay, both RGS1 and RGS16 were found to be equipotent in their ability to attenuate GPCR signaling . These results suggest that both RGS1 and RGS16 contribute to the sepsis-mediated decrease in GPCR signaling . Elevated levels of some RGSs may also lead to an increase in Gbetagamma-activated signaling pathways in the absence of GPCR agonists . Using a c-fos luciferase reporter gene that is responsive to Gbetagamma-activated signaling pathways, we observed a respective 8- and 7-fold increase in the basal luciferase in serum-deprived transfected mammalian cells overexpressing RGS1 or RGS16 . This suggests that RGSs play a role in promoting the sepsis-mediated increases in the activation of intracellular signal transduction pathways .

Neuroreport, 1999 Apr 26, 10(6), 1189 - 93
The bacterial Neo gene confers neomycin resistance to mammalian cochlear hair cells; Dulon D et al.; The aminoglycoside antibiotics are important agents in the treatment of bacterial infection . At pharmacological doses they also preferentially damage the sensory hair cells of the inner ear, leading to ototoxic hearing loss . However, it has been suggested that the mechanism of ototoxicity is different from that of bacterial toxicity . The bacterial neomycin phosphotransferase gene (Neo) confers resistance to this and related aminoglycoside antibiotics . To determine whether the Neo gene also confers resistance to vertebrate ototoxicity, the sensitivity of cochlear hair cells to neomycin was evaluated in mice with a targeted insertion of Neo . Organotypic cultures of the organ of Corti, isolated from neonatal wild-type mice and two strains of mice carrying the Neo gene, were cultured for 72 h in the absence (controls) or in the presence of 200 microM neomycin . Organs from wild-type mice showed no remaining outer hair cells and <25% of inner hair cells when incubated with neomycin . In contrast, organs from mice carrying the Neo gene showed no loss of hair cells after neomycin treatment.

Int J STD AIDS, 1999 May, 10(5), 305 - 8
Bacterial vaginosis in lesbians: evidence for lack of sexual transmission; McCaffrey M et al.; The effect of non-heterosexual factors on the vaginal flora has been studied . Ninety-one lesbians attending a specialist genitourinary medicine service for lesbians were studied . Bacterial vaginosis (BV) was diagnosed in 51.6% of them . While most of the women had previously had a male sexual partner, the presence of BV was not associated with a male sexual partner in the previous 12 months . A detailed analysis of lesbian sexual practices in the group did not relate BV to any sexual practice which would have the propensity to pass vaginal secretions from one to the other.

Jpn J Pharmacol, 1999 Apr, 79(4), 467 - 75
Bacterial expression and functional characterization of a rat thyroid hormone sulfotransferase, ST1B1; Fujita K et al.; At least three forms of phenol sulfotransferase (ST) ST1B1, ST1A1 and ST1C1 are contained in rat livers . To identify the form contributing to the metabolism of 3,3',5-triiodothyronine (T3), functional characterization of these forms was performed by expression in Escherichia coli . ST1B1 and ST1C1 were shown to be active on sulfation towards T3 with high affinity (Km: 44.4 and 25.8 microM, respectively), whereas ST1A1 had low affinity . In Western blotting using antibodies raised against the individual ST, hepatic contents of each ST were quantitatively determined . ST1B1 showed no clear sex-difference, whereas the level of ST1C1 was higher in adult males than adult females . The content of ST1B1 was 1.4, 6.8 and 10 times higher than that of ST1C1 in adult males, adult females and both sexes of immature rats, respectively . The developmental pattern of ST1B1 was similar to that of ST1A1, but differed from that of ST1C1 . These results indicate that ST1B1 and ST1C1 are involved in T3 metabolism in rats and ST1B1 is the constitutive form across sexes and ages.

Proc Natl Acad Sci U S A, 1999 Jun 8, 96(12), 6648 - 53
Feedback control of a master bacterial cell-cycle regulator; Domian IJ et al.; The transcriptional regulator CtrA controls several key cell-cycle events in Caulobacter crescentus, including the initiation of DNA replication, DNA methylation, cell division, and flagellar biogenesis . CtrA is a member of the response regulator family of two component signal transduction systems . Caulobacter goes to great lengths to control the time and place of the activity of this critical regulatory factor during the cell cycle . These controls include temporally regulated transcription and phosphorylation and spatially restricted proteolysis . We report here that ctrA expression is under the control of two promoters: a promoter (P1) that is active only in the early predivisional cell and a stronger promoter (P2) that is active in the late predivisional cell . Both promoters exhibit CtrA-mediated feedback regulation: the early P1 promoter is negatively controlled by CtrA, and the late P2 promoter is under positive feedback control . The CtrA protein footprints conserved binding sites within the P1 and P2 promoters . We propose that the P1 promoter is activated after the initiation of DNA replication in the early predivisional cell . The ensuing accumulation of CtrA results in the activation of the P2 promoter and the repression of the P1 promoter late in the cell cycle . Thus, two transcriptional feedback loops coupled to cell cycle-regulated proteolysis and phosphorylation of the CtrA protein result in the pattern of CtrA activity required for the temporal and spatial control of multiple cell-cycle events.

J Biol Chem, 1999 Jun 11, 274(24), 16736 - 40
Identification of critical, conserved vicinal aspartate residues in mammalian and bacterial ADP-ribosylarginine hydrolases; Konczalik P et al.; NAD:arginine ADP-ribosyltransferases and ADP-ribosylarginine hydrolases catalyze opposing arms of a putative ADP-ribosylation cycle . ADP-ribosylarginine hydrolases from mammalian tissues and Rhodospirillum rubrum exhibit three regions of similarity in deduced amino acid sequence . We postulated that amino acids in these consensus regions could be critical for hydrolase function . To test this hypothesis, hydrolase, cloned from rat brain, was expressed as a glutathione S-transferase fusion protein in Escherichia coli and purified by glutathione-Sepharose affinity chromatography . Conserved amino acids in each of these regions were altered by site-directed mutagenesis . Replacement of Asp-60 or Asp-61 with Ala, Gln, or Asn, but not Glu, significantly reduced enzyme activity . The double Asp-60 --> Glu/Asp-61 --> Glu mutant was inactive, as were Asp-60 --> Gln/Asp-61 --> Gln or Asp-60 --> Asn/Asp-61 --> Asn . The catalytically inactive single and double mutants appeared to retain conformation, since they bound ADP-ribose, a substrate analogue and an inhibitor of enzyme activity, with affinity similar to that of the wild-type hydrolase and with the expected stoichiometry of one . Replacing His-65, Arg-139, Asp-285, which are also located in the conserved regions, with alanine did not change specific activity . These data clearly show that the conserved vicinal aspartates 60 and 61 in rat ADP-ribosylarginine hydrolase are critical for catalytic activity, but not for high affinity binding of the substrate analogue, ADP-ribose.

J Pediatr, 1999 Jun, 134(6), 725 - 9
C-reactive protein is useful in distinguishing Gram stain-negative bacterial meningitis from viral meningitis in children; Sormunen P et al.; OBJECTIVE: To clarify to what extent Gram stain-negative bacterial meningitis can be distinguished from viral meningitis by assessment of cerebrospinal fluid (CSF) and blood indices and serum C-reactive protein (CRP) in children over 3 months of age . DESIGN: Common CSF indices, blood leukocyte counts, and serum CRP values were compared between patients with bacterial meningitis who had a positive CSF bacterial culture but a negative Gram stain and patients with viral meningitis . POPULATION: Three hundred twenty-five consecutive patients with CSF culture-proven bacterial meningitis, for whom Gram stain was negative in 55 cases, and 182 children with proven or presumed viral meningitis . RESULTS: Significant differences between patients with bacterial and viral meningitis were found in all indices with large overlap in all except serum CRP . In patients with bacterial meningitis, the mean CSF glucose concentration, protein concentration, leukocyte count, blood leukocyte count, and serum CRP were 2.9 mmol/L (52 mg/dL), 1.88 g/L, 4540 x 10(6)/L, 18.0 x 10(9)/L, and 115 mg/L; and in those with viral meningitis, mean values were 3.3 mmol/L (59 mg/dL), 0.52 g/L, 240 x 10(6)/L, 10.6 x 10(9)/L, and <20 mg/L, respectively . Of the tests investigated in this study, only serum CRP was capable of distinguishing Gram stain-negative bacterial meningitis from viral meningitis on admission with high sensitivity (96%), high specificity (93%), and high negative predictive value (99%) . CONCLUSION: Exclusion of bacterial meningitis with only the conventional tests is difficult . Combined with careful physical examination and CSF analyses, serum CRP measurement affords substantial aid.

Trends Microbiol, 1999 May, 7(5), 191 - 5
Pathoadaptive mutations: gene loss and variation in bacterial pathogens; Sokurenko EV et al.; Pathogenicity-adaptive, or pathoadaptive, mutations represent a genetic mechanism for enhancing bacterial virulence without horizontal transfer of specific virulence factors . Pathoadaptive evolution can be important within single infections and for defining the population structure of a pathogenic species.

J Microbiol Methods, 1999 May, 36(1-2), 139 - 45
Bacterial bio-mediated calcite precipitation for monumental stones conservation: methods of evaluation; Tiano P et al.; The weathering of monumental stones is a complex process inserted in the more general 'matter transformation cycle' operated by physical, chemical and biological factors . The consequence of these combined actions is a loss of cohesion with dwindling and scaling of stone material and the induction of a progressive mineral matrix dissolution . In the case of calcareous stones, calcite leaching increases the material porosity and decreases its mechanical features with a general weakening of the superficial structural strength . Attempts to stop, or at least to slow down, deterioration of monumental stones has been made by conservative treatments with both inorganic or organic products . More recent studies show a new approach to hinder these phenomena by inducing a bio-mediated precipitation of calcite directly inside the stone porosity . This can be achieved either through the application of organic matrix macromolecules extracted from sea shells or of living bacteria . The effectiveness of the treatment using calcinogenic bacteria has been evaluated with laboratory tests specifically developed to evaluate the parameters such as : porosity, superficial strength and chromatic changes, influenced by the treatment itself . The results obtained seem to indicate that this type of treatment might not be suitable for monumental stone conservation.

Cancer Metastasis Rev, 1998-99, 17(3), 285 - 94
The bacterial lacZ gene: an important tool for metastasis research and evaluation of new cancer therapies; Kruger A et al.; The bacterial lacZ gene has been used to genetically tag tumor cells . This has been of value, specifically in metastasis research where it allowed to visualize micrometastases and single tumor cells in tissues . lacZ tagging has also provided the feasibility of re-isolating metastatic tumor cell populations for ex vivo molecular analyses . This review summarizes studies that have utilized lacZ tagged tumor cells to understand aspects of metastasis including dormancy, tumor-host interactions, gene modulation and anti-tumor immunity . lacZ tagging is also a valuable tool for evaluating cancer therapies.

Am J Respir Crit Care Med, 1999 Jun, 159(6), 1981 - 4
Analysis of the Kveim-Siltzbach test reagent for bacterial DNA; Richter E et al.; The sarcoid spleen-derived reagent for the Kveim-Siltzbach test (KST) elicits a sarcoid-specific, granulomatous, cutaneous response used to establish the diagnosis of sarcoidosis . In the context of the ongoing discussion of a bacterial cause of sarcoidosis we asked the question whether bacterial DNA could be found in the KST reagent . For this purpose two different KST reagents, an identical preparation from a normal spleen, and a native sarcoid spleen were analyzed by polymerase chain reaction (PCR) employing universal primers detecting conserved DNA sequences coding for bacterial ribosomal 16S RNA . Neither KST reagents, the control preparation, nor the spleen yielded a positive signal, indicating that the preparations are free of bacterial contamination . Because the KST reagent elicits granuloma, these results do not support the hypothesis of a bacterial cause of sarcoid granuloma.

Adv Ther, 1998 Nov-Dec, 15(6), 330 - 41
Use of a polyvalent bacterial lysate in patients with recurrent respiratory tract infections: results of a prospective, placebo-controlled, randomized, double-blind study; Rutishauser M et al.; Respiratory tract infections (RTIs) are the most common infections in humans, and it is difficult to effectively treat patients with increased susceptibility to these ailments . LW 50020 (Luivac; Paspat oral), an oral immunomodulator consisting of the antigens of seven bacteria commonly involved in RTIs, has been developed for the induction of specific and nonspecific immune responses of the mucosa-associated lymphoid tissue . In this placebo-controlled study, the efficacy and safety of the tablet formulation of LW 50020 were evaluated in children and adults with recurrent RTIs . Tablets were taken once daily during two periods of 4 weeks each, interrupted by a treatment-free interval of 4 weeks . The main endpoint of the study, a clinical severity score that evaluated treatment benefits, was significantly lower in the second study period in patients treated with the bacterial lysate compared to patients given placebo . A comparison of the infection rates in the first and second study periods of patients treated with LW 50020 revealed a placebo-corrected reduction of 39% in children and a placebo-corrected reduction of 44% in adolescents and adults . The placebo-corrected duration of infections was shortened by 47% in children and by 55% in older patients . No serious drug-related side effects occurred . This study demonstrated that the oral bacterial immunomodulator LW 50020 is efficacious in treating patients with recurrent RTIs.

Adolesc Med, 1990 Jun, 1(2), 325 - 332
Bacterial Skin Infections in Adolescents; Prose NS et al.; This article reviews the salient features of diagnosis and treatment of the more common bacterial infections in adolescents, including impetigo contagiosa, bullous impetigo, cellulitis and erysipelas, folliculitis, furunculosis and carbunculosis, blistering distal dactylitis, toxic shock syndrome, and dog and cat bites.

Biochemistry, 1999 May 18, 38(20), 6449 - 59
NMR experiments reveal distinct antibody-bound conformations of a synthetic disaccharide representing a general structural element of bacterial lipopolysaccharide epitopes; Haselhorst T et al.; The recognition reactions between a synthetic disaccharide alpha-Kdo-(2-->4)-alpha-Kdo-(2-->O)-allyl and two monoclonal antibodies (mAbs) were studied by NMR, yielding two distinct bound conformations of the carbohydrate ligand . One mAb, S23-24, recognizes the disaccharides alpha-Kdo-(2-->4)-alpha-Kdo-(2-->O)-allyl and alpha-Kdo-(2-->8)-alpha-Kdo-(2-->O)-allyl with similar affinities, whereas mAb S25-2 binds to the disaccharide alpha-Kdo-(2-->8)-alpha-Kdo-(2-->O)-allyl with an approximately 10-fold higher affinity than to the disaccharide alpha-Kdo-(2-->4)-alpha-Kdo-(2-->O)-allyl . Compared to S25-2, S23-24 binds to alpha-Kdo-(2-->4)-alpha-Kdo-(2-->O)-allyl with an approximately 50-fold increased affinity . We used NMR experiments that are based on the transferred NOE effect, specifically, trNOESY, trROESY, QUIET-trNOESY, and MINSY experiments, to show that the (2-->8)-specific mAb, S25-2, stabilizes a conformation of the alpha-(2-->4)-linked disaccharide that is not highly populated in solution . S23-24 recognizes two conformations of alpha-Kdo-(2-->4)-alpha-Kdo-(2-->O)-allyl, one that is highly populated in aqueous solution and another conformation that is similar to the one bound by S25-2 . This is the first example where it is experimentally shown that a carbohydrate ligand may adopt different bioactive conformations upon interaction with mAbs with different fine specificities . Our NMR studies indicate that a careful examination of spin diffusion is critical for the analysis of bioactive conformations of carbohydrate ligands.

Methods Enzymol, 1999, 303, 495 - 511
Solid-phase differential display and bacterial expression systems in selection and functional analysis of cDNAs; Stahl S et al.; Differential gene expression can be expected during activation and differentiation of cells as well as during pathological conditions, such as cancer . A number of strategies have been described to identify and understand isolated differentially expressed genes . The differential display methodology has rapidly become a widely used technique to identify differentially expressed mRNAs . In this chapter we described a variant of the differential display method based on solid-phase technology . The solid-phase procedure offers an attractive alternative to solution-based differential display because minute amounts of sample can be analyzed in considerably less time than previously . The employed solid support, monodisperse super paramagnetic beads, which circumvents precipitation and centrifugations steps, has also allowed for optimization of the critical enzymatic and preparative steps in the differential display methodology . We also described how bacterial expression can be used as a means to elucidate gene function . An efficient dual-expression system was presented, together with a basic concept describing how parallel expression of selected portions of cDNAs can be used for production of cDNA-encoded proteins as parts of affinity-tagged fusion proteins . The fusion proteins are suitable both for the generation of antibodies reactive to the target cDNA-encoded protein and for the subsequent affinity enrichment of such antibodies . Affinity-enriched antibodies have proved to be valuable tools in various assays, including immunoblotting and immunocytochemical staining, and can thus be used to localize the target cDNA-encoded protein to certain cells in a tissue section or even to a specific cell compartment or organelle within a cell . High-resolution localization of a cDNA-encoded protein would provide valuable information toward the understanding of protein function.

Rev Med Chil, 1998 Nov, 126(11), 1323 - 9
{Prognostic factors in acute bacterial meningitis in children . A case control study}; Skarmeta M et al.; BACKGROUND: The prognosis of acute bacterial meningitis continues to be poor in our country . Previous studies suggest that the delay in diagnosis has an important prognostic value . AIM: To study the influence of diagnosis timing and the clinical conditions of children with acute bacterial meningitis on admission on death and incidence of gross sequelae . PATIENTS AND METHODS: Charts of children deceased or discharged with gross sequelae as consequence of an acute bacterial meningitis were selected . To each of these cases, 4 children with the same diagnosis but discharged in good conditions were selected as controls . Variables recorded were time and number of visits previous to the diagnosis, etiology of meningitis, neurological, respiratory, digestive and hemodynamic involvement on admission . RESULTS: Fifty seven cases and 224 controls were studied . Most cases were 12 months old or less (OR 4.1, 95% CI = 1.97-8.7) . Diagnosis made on the first visit or within the first 24 hours of disease, improved prognosis (OR 0.25, 95% CI = 0.07-0.78) . An age of less than 12 months and a diagnosis made after more than 12 hours of disease or after more than one consultation interacted multiplying their effect on a dismal prognosis . Coma on admission (OR 7.95% CI = 3-14.3) and S Pneumoniae etiology (OR 7, CI 95% = 3.4, 14.3) were also associated with a bad prognosis . CONCLUSIONS: Early diagnosis of acute bacterial meningitis is protective for death or gross sequelae at discharge . Age, coma and S Pneumoniae etiology are the main factors associated with a poor prognosis.

J Antibiot (Tokyo), 1999 Mar, 52(3), 281 - 7
New types of liposidomycins produced by Streptomyces that inhibit bacterial peptidoglycan synthesis . Structure elucidation of fatty acid components by tandem mass spectrometry; Esumi Y et al.; The structures of the fatty acid components of various new liposidomycins were determined using tandem mass spectrometry; the negative FAB/MS/MS/MS technique for liposidomycins with a 3-methylglutaric acid moiety and the negative FAB/MS/MS technique for liposidomycins without a 3-methylglutaric acid moiey . This structural information was obtained by analysis of peaks due to charge-remote fragmentations for 3-hydroxycarboxylate anions or carboxylate anions which were generated from liposidomycin molecules in a mass spectrometer . The MS/MS/MS technique that can exclude the matrix-derived and/or interfering ions showed higher sensitivity than the MS/MS technique.

Microbios, 1998, 96(383), 33 - 8
Location of haemagglutinin in bacterial cells of Fusobacterium necrophorum subsp . necrophorum; Kanoe M et al.; The location of haemagglutinin (HA) of Fusobacterium necrophorum subsp . necrophorum VPI 2891 strain was investigated by immunofluorescence, confocal laser scan microscopy and immunoelectron microscopy . The immunofluorescence study demonstrated the fluorescence specific for the HA on the bacterial cells and confocal laser scan microscopy indicated similar fluorescence around the cross section of the bacterial cell . The immunoelectron microscopic study also revealed that the protein A-gold conjugates were located around the bacterial surfaces . These findings suggest that HA is one of the components of the cell surfaces of F . necrophorum subsp, necrophorum.

Mol Pharmacol, 1999 Jun, 55(6), 957 - 69
A regulatory domain (R1-R2) in the amino terminus of the N-methyl-D-aspartate receptor: effects of spermine, protons, and ifenprodil, and structural similarity to bacterial leucine/isoleucine/valine binding protein; Masuko T et al.; There are complex interactions between spermine, protons, and ifenprodil at N-methyl-D-aspartate receptors . Spermine stimulation may involve relief of proton inhibition, whereas ifenprodil inhibition may involve an increase in proton inhibition . We studied mutations at acidic residues in the NR1 subunit using voltage-clamp recording of NR1/NR2B receptors expressed in Xenopus oocytes . Mutations at residues near the site of the exon-5 insert, including E181 and E185, reduced spermine stimulation and proton inhibition . Mutation NR1(D130N) reduced sensitivity to ifenprodil by more than 500-fold, but had little effect on sensitivity to spermine and pH . Mutations at six other residues in this region of the NR1 subunit reduced the potency and, in some cases, the maximum effect of ifenprodil . These mutants did not affect sensitivity to pH, glutamate, glycine, or other hallmark properties of N-methyl-D-aspartate channels such as Mg2+ block and Ba2+ permeability . Residues in this region presumably form part of the ifenprodil-binding site . To model this region of NR1 we compared the predicted secondary structure of NR1 (residues 19-400) with the known structures of 1,400 proteins . This region of NR1 is most similar to bacterial leucine/isoleucine/valine binding protein, a globular amino acid binding protein containing two lobes, similar to the downstream S1-S2 region of glutamate receptors . We propose that the tertiary structure of NR1(22-375) is similar to leucine/isoleucine/valine binding protein, containing two "regulatory" domains, which we term R1 and R2 . This region, which contains the binding sites for spermine and ifenprodil, may influence the downstream S1 and S2 domains that constitute the glycine binding pocket.

J Biol Chem, 1999 Jun 4, 274(23), 16311 - 9
Molecular cloning and characterization of a mouse homolog of bacterial ClpX, a novel mammalian class II member of the Hsp100/Clp chaperone family; Santagata S et al.; In this paper, we present the molecular cloning and characterization of a murine homolog of the Escherichia coli chaperone ClpX . Murine ClpX shares 38% amino acid sequence identity with the E . coli homolog and is a novel member of the Hsp100/Clp family of molecular chaperones . ClpX localizes to human chromosome 15q22.2-22.3 and in mouse is expressed tissue-specifically as one transcript of approximately 2.9 kilobases (kb) predominantly within the liver and as two isoforms of approximately 2.6 and approximately 2.9 kb within the testes . Purified recombinant ClpX displays intrinsic ATPase activity, with a Km of approximately 25 microM and a Vmax of approximately 660 pmol min-1 microgram-1, which is active over a broad range of pH, temperature, ethanol, and salt parameters . Substitution of lysine 300 with alanine in the ATPase domain P-loop abolishes both ATP hydrolysis and binding . Recombinant ClpX can also interact with its putative partner protease subunit ClpP in overexpression experiments in 293T cells . Subcellular studies by confocal laser scanning microscopy localized murine ClpX green fluorescent protein fusions to the mitochondria . Deletion of the N-terminal mitochondrial targeting sequence abolished mitochondrial compartmentalization . Our results thus suggest that murine ClpX acts as a tissue-specific mammalian mitochondrial chaperone that may play a role in mitochondrial protein homeostasis.

PDA J Pharm Sci Technol, 1999 Jan-Feb, 53(1), 11 - 22
Evaluation of the effects of fragmented steam exposure cycles on the survival of bacterial spores; Shirtz JT et al.; The purpose of this study was to examine the population and resistance characteristics of bacterial spores which have been exposed to an abbreviated steam sterilization cycle . The philosophy of many pharmaceutical manufacturers is to require a second complete terminal sterilization cycle in the event of an unplanned interruption during the terminal sterilization of a production batch . The impact of abbreviated steam sterilization cycles was examined for their effect on the survivability and resistance of bacterial spores following an inadequate sterilization cycle . Steam sterilization cycles of two minutes and four minutes were performed on separate groups of Biological Indicator spore strips . These groups were then held at room temperature and re-exposed to a range of sterilization conditions after 24, 48, and 72 hours, i.e., start cycle, abort, hold, start cycle, abort . Spore survivor curves were calculated and resistance estimations were determined . The results of the study indicated that the log level of the surviving spores remained fairly constant, but variability within groups increased as sterilization time increased . The resistance of these surviving spores, as measured by D value, also remained relatively constant throughout the holding period . Abbreviated cycles were similarly conducted on ampules containing a spore suspension, and the spore populations and moist heat resistances were determined over time . Contrary to the spore strip, the population of the subject ampules was less stable showing a gradual decline over the same observation period . The study also included a comparison of the surviving population of short and long fragmented cycles . The results of this study demonstrate that a second complete sterilization cycle is unnecessary to assure the absence of living matter in the sterilized units.

Med Hypotheses, 1999 Jan, 52(1), 85 - 7
Could antioxidant therapy reduce the incidence of deafness following bacterial meningitis?
Maurizi CP.
Sensorineural hearing loss following acute bacterial meningitis could be caused by hydroxyl radicals generated by the inflammatory response . Obstruction of cerebrospinal fluid circulation through the tela choroidae of the choroid plexuses, with subsequent rupture of the tela choroidae, would expose the auditory nerve to selective radical damage . Acute administration of lipophilic antioxidants might provide the auditory nerve with increased protection.

Mol Cells, 1999 Apr 30, 9(2), 115 - 8
Bacterial chemoreceptors: recent progress in structure and function; Mowbray SL; The behavior of a bacterial cell is determined by the interplay between transmembrane receptor molecules and a cytoplasmic kinase that is linked to the flagellar apparatus . In the absence of external stimulus, a balance exists between stresses in the periplasmic region of receptor molecules, and compensating cytoplasmic forces . A response, positive or negative, is due to a temporary disturbance in this balance, with corresponding alterations in kinase activity, and ultimately, of swimming behavior . Methylation acts to restore the balance by changing the properties of the receptor . Because methylation is slow, a response will continue for a period of time following stimulation . The mechanisms by which these processes occur are now being elucidated at the molecular level, and should soon make bacterial chemotaxis the first available picture of a complete sensory system.

FEMS Microbiol Lett, 1999 May 15, 174(2), 255 - 63
Electron beam fragmentation of bacterial polysaccharides as a method of producing oligosaccharides for the preparation of conjugate vaccines; Pawlowski A et al.; End-group mediated conjugation of bacterial polysaccharides (PSs) to carrier proteins containing T-helper cell epitopes renders such polysaccharides immunogenic also in young infants . Optimal construction of such conjugate vaccines requires fragmentation of the PS prior to the coupling reaction . In the present study a general simple and inexpensive method for the fragmentation of PSs is presented . It is based on the irradiation of isolated PSs in an electron beam accelerator . Exposure of isolated pneumococcal capsular polysaccharides (PnPSs) to ionizing radiation resulted in their partial depolymerization in a radiation dose-dependent manner . Radiation, unlike sonication, generated PnPS fragments of molecular size lower than 50 kDa and as small as 1.5 kDa when high radiation doses were used . These PnPS fragments have terminal reducing groups that can be easily used for chemical activation and subsequent coupling to any chosen carrier protein . The radiation-produced PnPS fragments retained their antigenic epitopes, when compared to native, full-size PnPSs as determined by enzyme-linked immunoassay.

FEMS Microbiol Lett, 1999 May 15, 174(2), 251 - 3
FramePlot: a new implementation of the frame analysis for predicting protein-coding regions in bacterial DNA with a high G + C content; Ishikawa J et al.; FramePlot is a web-based tool for predicting protein-coding regions in bacterial DNA with a high G + C content, such as Streptomyces . The graphical output provides for easy distinction of protein-coding regions from non-coding regions . The plot is a clickable map . Clicking on an ORF provides not only the nucleotide sequence but also its deduced amino acid sequence . These sequences can then be compared to the NCBI sequence database over the Internet . The program is freely available for academic purposes at http://www.nih.go.jp/jun/cgi-bin/frameplot.pl.

Transfus Clin Biol, 1999 Apr, 6(2), 124 - 8
{Diagnostic difficulties of transfusion incidents due to bacterial contamination: report of two cases}; Renom P et al.; The French hemovigilance system has recently underlined the relative frequency of transfusion-associated bacterial sepsis and the necessity to remain constantly aware of this eventuality . We describe the experience of a hematology unit over a 18-month period: 189 acute transfusion reactions were registered and bacterial cultures of the implicated cellular blood products realized in 82 of them . A positive result was obtained in two cases . For both cases, clinical symptoms of transfusion reaction were limited to a lasting fever, and a skin rash occurred in aplastic patients with preexisting signs of sepsis . The causal relationship between this contamination and the transfusion reaction is difficult to establish . Clinical manifestations justifying a bacterial inquiry must therefore be more precisely defined, particularly in multitransfused patients.

Proc Natl Acad Sci U S A, 1999 May 25, 96(11), 6183 - 8
Identification of the proton pathway in bacterial reaction centers: inhibition of proton transfer by binding of Zn2+ or Cd2+; Paddock ML et al.; The reaction center (RC) from Rhodobacter sphaeroides converts light into chemical energy through the light induced two-electron, two-proton reduction of a bound quinone molecule QB (the secondary quinone acceptor) . A unique pathway for proton transfer to the QB site had so far not been determined . To study the molecular basis for proton transfer, we investigated the effects of exogenous metal ion binding on the kinetics of the proton-assisted electron transfer kAB(2) (QA-*QB-* + H+ --> QA(QBH)-, where QA is the primary quinone acceptor) . Zn2+ and Cd2+ bound stoichiometrically to the RC (KD </= 0.5 microM) and reduced the observed value of kAB(2) 10-fold and 20-fold (pH 8.0), respectively . The bound metal changed the mechanism of the kAB(2) reaction . In native RCs, kAB(2) was previously shown to be rate-limited by electron transfer based on the dependence of kAB(2) on the driving force for electron transfer . Upon addition of Zn2+ or Cd2+, kAB(2) became approximately independent of the electron driving force, implying that the rate of proton transfer was reduced (>/= 10(2)-fold) and has become the rate-limiting step . The lack of an effect of the metal binding on the charge recombination reaction D+*QAQB-* --> DQAQB suggests that the binding site is located far (>10 A) from QB . This hypothesis is confirmed by preliminary x-ray structure analysis . The large change in the rate of proton transfer caused by the stoichiometric binding of the metal ion shows that there is one dominant site of proton entry into the RC from which proton transfer to QB-* occurs.

Arzneimittelforschung, 1999 Apr, 49(4), 344 - 50
Effects of erdosteine and its metabolites on bacterial adhesiveness; Braga PC et al.; Erdosteine (CAS 84611-23-4) is administered as a mucolytic drug in patients with pulmonary disorders who suffer from a thickening of bronchial mucus with altered physico-chemical characteristics . Erdosteine itself does not have a free thiol group but its metabolization produces active metabolites with a -SH group that is capable of breaking disulfide bonds of mucins and improving the mucociliary clearance of the airways, and thus reproducing the effects of the class of muco-active drugs having a thiol group . It has also been reported that muco-active drugs with this group reduce bacterial adhesiveness to human mucosal cells . The aim of this study was to investigate whether erdosteine and its SH-metabolites are capable of interfering with bacterial adhesiveness . Metabolite I significantly reduces both S . aureus and E . coli adhesiveness to human mucosal epithelial cells at concentrations of 2.5, 5 and 10 micrograms/ml . The same concentrations of erdosteine, metabolite II, metabolite III and N-acetylcysteine (as a control drug) were devoid of such activity, whereas the results of hemagglutination and hydrophobicity assays showed that the behaviour of metabolite I overlapped that of bacterial adhesiveness, thus indicating that interference takes place at a fimbrial level . This is confirmed by the fact that the incubation of human buccal cells with drugs does not reduce the adhesiveness of untreated bacteria . The presence of this additional activity in a muco-active drug is useful because bacteria not only adhere to epithelial cells but also to tracheobronchial secretions.

Protein Expr Purif, 1999 Jun, 16(1), 84 - 90
Bacterial expression and purification of the Fab fragment of a monoclonal antibody specific for the low-density lipoprotein receptor-binding site of human apolipoprotein E; Raffai R et al.; We report the bacterial expression and the purification of a monoclonal antibody (mAb) specific for an epitope that coincides with the LDL receptor (LDLr)-binding domain of human apolipoprotein E (apoE) . This antibody resembles the LDLr in its primary structure and its specificity for apoE variants . The recombinant Fab (rFab) fragment of mAb 2E8, consisting of the entire light chain and the Fd portion of the heavy chain, was expressed in Escherichia coli and purified to homogeneity . Purification was facilitated by including a five-histidine carboxyl-terminal extension on the Fd chain . A 5- to 10-fold difference in yield of the antibody was observed when the plasmid was expressed in two different strains of E . coli . Typically 2-6 mg of rFab per liter of culture medium was recovered in the periplasm of the TG1 strain and less than 1 mg was recovered in the periplasm of the XL1-Blue strain . Culture temperatures above 35 degrees C or inclusion of sucrose in the medium reduced rFab yields . The 2E8 rFab was indistinguishable from Fab prepared from 2E8 hybridoma-generated IgG with respect to its affinity and fine specificity . We are using this system to express a panel of 2E8 variant Fabs that will be used as probes to establish the structural features responsible for the binding of apoE to the LDLr .

Eur J Biochem, 1999 Jun, 262(2), 358 - 64
Investigation on the detergent role in the function of secondary quinone in bacterial reaction centers; Agostiano A et al.; In this paper are reported studies on the detergent role in isolated reaction centers (RC) from Rhodobacter sphaeroides, over a large range of lauryldimethylamino-N-oxide (LDAO) concentrations, in influencing the thermodynamics of the quinone exchange reaction as well as the protein aggregation . The occurrence of the quinone exchange reaction between the QB-binding site (where QB is the second quinone molecule of two in the RC) and the ubiquinone 0 dissolved in the different environments (water, LDAO micelles and detergent phase of the protein-detergent complex) has also been analyzed . Measurements carried out in QB-depleted RC to which exogenous quinone has been added show that the relative amplitudes of the slow and fast phase of the recombination reaction depend on this parameter . The overall amount of the restored QB-functionality is affected by the concentration of the LDAO in solution . Interpolation of the titration curves with a quadratic function obtained by simple considerations allowed the binding constant of UQ0 to the QB-binding site to be calculated . From the fitting procedure, the distribution of the quinone in the different environments present in solution was evaluated, indicating that the exchange reaction can take place only between the QB-site and the detergent phase . The dependence of the quinone pool size upon the volume of the phase in which the interacting quinone is solubilized is also discussed . The increasing difficulty in saturating the QB-pocket above the LDAO critical micellar concentration is finally related to the association of protein-detergent complexes to form large protein clusters.

Genomics, 1999 May 15, 58(1), 9 - 17
Construction and characterization of an eightfold redundant dog genomic bacterial artificial chromosome library; Li R et al.; A large insert canine genomic bacterial artificial chromosome (BAC) library was built from a Doberman pinscher . Approximately 166,000 clones were gridded on nine high-density hybridization filters . Insert analysis of randomly selected clones indicated a mean insert size of 155 kb and predicted 8.1 coverage of the canine genome . Two percent of the clones were nonrecombinant . Chromosomal fluorescence in situ hybridization studies of 60 BAC clones indicated no chimerism . The library was hybridized with dog PCR products representing eight genes (ADA, TNFA, GCA, MYB, HOXA, GUSB, THY1, and TOP1) . The resulting positive clones were characterized and shown to be compatible with an eightfold redundant library .

Br J Gen Pract, 1999 Feb, 49(439), 119 - 21
Improving diagnostic accuracy of bacterial pharyngitis by near patient measurement of C-reactive protein (CRP)
Gulich MS, Matschiner A, Gluck R, Zeitler HP.
BACKGROUND: Sore throat or pharyngitis is an extremely prevalent condition in primary care . There is a diagnostic dilemma in differentiating bacterial and non-bacterial infections for adequate use of antibiotics . Standard diagnostic procedures take too long for an immediate decision . AIM: To evaluate, if near patient C-reactive protein measurement in the general practice surgery improves diagnostic accuracy . METHOD: One hundred and seventy-nine consecutive patients with sore throat, from 15 general practitioners (GPs) in southern Germany (phase 1) and 161 consecutive patients from 14 GPs (phase 2), were examined physically and a throat-swab was taken and white blood-cell count (WBC) and CRP-measurement were performed . In phase 1, CRP was measured centrally to assess the method's diagnostic value and the adequate threshold . In the second phase, near patient CRP was measured and CRP values were used to make a diagnosis . RESULTS: Using relative operating characteristics (ROC) analysis, the diagnostic value of CRP measurement was much better than WBC count (area under curve = 0.85 versus 0.68) . All diagnostic parameters improved when using the near patient CRP measurement . Sensitivity went up from 0.61 (95% confidence interval = 0.45-0.75) to 0.78 (0.61-0.90), specificity went up from 0.73 (0.65-0.81) to 0.82 (0.73-0.88) . Positive and negative predictive value improved significantly as well . Diagnostic accuracy went up from 70.1% to 81.0% . Out of 1000 theoretical patients with sore throat, 109 more will be treated correctly when using CRP measurement as a diagnostic tool . CONCLUSIONS: Use of near patient CRP measurement can improve diagnostic accuracy in the differentiation of bacterial and non-bacterial pharyngitis in primary care, and potentially results in a more adequate use of antibiotics.

Anal Biochem, 1999 May 15, 270(1), 133 - 9
Specific immobilization of in vivo biotinylated bacterial luciferase and FMN:NAD(P)H oxidoreductase; Min DJ et al.; Bacterial bioluminescence, catalyzed by FMN:NAD(P)H oxidoreductase and luciferase, has been used as an analytical tool for quantitating the substrates of NAD(P)H-dependent enzymes . The development of inexpensive and sensitive biosensors based on bacterial bioluminescence would benefit from a method to immobilize the oxidoreductase and luciferase with high specific activity . Toward this end, oxidoreductase and luciferase were fused with a segment of biotin carboxy carrier protein and produced in Escherichia coli . The in vivo biotinylated luciferase and oxidoreductase were immobilized on avidin-conjugated agarose beads with little loss of activity . Coimmobilized enzymes had eight times higher bioluminescence activity than the free enzymes at low enzyme concentration and high NADH concentration . In addition, the immobilized enzymes were more stable than the free enzymes . This immobilization method is also useful to control enzyme orientation, which could increase the efficiency of sequentially operating enzymes like the oxidoreductase-luciferase system .

QJM, 1999 Mar, 92(3), 151 - 7
Cerebral malaria versus bacterial meningitis in children with impaired consciousness; Berkley JA et al.; Cerebral malaria (CM) and acute bacterial meningitis (ABM) are the two common causes of impaired consciousness in children presenting to hospital in sub-Sahara Africa . Since the clinical features of the two diseases may be very similar, treatment is often guided by the initial laboratory findings . However, no detailed studies have examined the extent to which the laboratory findings in these two diseases may overlap . We reviewed data from 555 children with impaired consciousness admitted to Kilifi District Hospital, Kenya . Strictly defined groups were established based on the malaria slide, cerebrospinal fluid (CSF) leucocyte count and the results of blood and CSF culture and CSF bacterial antigen testing . Our data suggests significant overlap in the initial CSF findings between CM and ABM . The absolute minimum proportions of children with impaired consciousness and malaria parasitaemia who also had definite bacterial meningitis were 4% of all children and 14% of children under 1 year of age . The estimated maximum proportion of all children with impaired consciousness and malaria parasitaemia in whom the diagnosis was dual or unclear was at least 13% . The finding of malaria parasites in the blood of an unconscious child in sub-Saharan Africa is not sufficient to establish a diagnosis of cerebral malaria, and acute bacterial meningitis must be actively excluded in all cases.

Dermatology, 1999, 198(2), 130 - 2
Helicobacter pylori as a possible bacterial focus of chronic urticaria; Wustlich S et al.; BACKGROUND: Chronic urticaria is one of the most frequent skin diseases . Its cause, however, remains unsolved in a large number of cases . Recent investigations pointed to a potential role of Helicobacter pylori infection of the upper gastrointestinal tract as a possible causative agent in chronic urticaria . OBJECTIVE: The aim of this study was to examine the effect of a 14-day eradication therapy on chronic urticaria . METHODS: Thirty patients with chronic urticaria and confirmed H . pylori infection were treated with amoxicillin and omeprazole . Follow-up was conducted over a period of 6 months concerning eradication of H . pylori and remission of urticaria . RESULTS: Only 8 out of 30 patients (26.7%) showed clinical improvement or disappearance of their urticarial symptoms . CONCLUSION: Though our results do not support the preliminary data of previous studies, the role of H . pylori as a possible bacterial focus of chronic urticaria has to be further investigated.

Curr Opin Microbiol, 1999 Apr, 2(2), 214 - 9
Starvation, cessation of growth and bacterial aging; Nystrom T; Several components of different Escherichia coli regulons are integrated to prevent premature oxidative deterioration of starving cells . The interconnected regulation of these regulons encompasses oxidation signalling, sigma factor competition, and possibly also the use of sigma factor inhibitors . Recent data demonstrate that stasis-induced oxidation targets both DNA and protein and that some enzymes are specifically susceptible to oxidative attack.

J Biomed Mater Res, 1999 Jun 15, 45(4), 395 - 403
Toxicity measurement of orthopedic implant alloy degradation products using a bioluminescent bacterial assay; Shettlemore MG et al.; The toxicity of aqueous metal solutions representative of ionic degradation products from orthopedic implant alloys was determined using a bacterial bioluminescence assay, Microtox . The toxicity of forms of the individual elements released from ASTM F75 Co-Cr-Mo (Co-Cr-Mo), F138 316L stainless steel (316L), and F136 Ti-6Al-4V (Ti-6Al-4V) was first determined, and a mathematical model was developed to predict the toxicity of mixtures of these ions . Aqueous metal solutions were then mixed according to the proportions of the ions found in these alloys, and their toxicity was measured with Microtox . Mixture behavior was classified as synergistic, antagonistic, or additive by comparing measured toxicity to predicted toxicity . Since relating these tests to actual implant corrosion processes can be confounded by selective leaching, the predicted and measured toxicity of aqueous metal solutions mixed according to proportions representative of selective leaching were next determined, and the mixture behaviors were classified as before . The most toxic individual alloying elements were found to be hexavalent Cr, Ni, and Co, in that order: a finding in accord with prior biocompatibility research . Co-Cr-Mo was found to be the most toxic alloy mixture of both those combined according to alloy composition and those combined to reflect selective leaching . The Ti-6Al-4V mixtures were found to behave synergistically, while the Co-Cr-Mo and 316L mixtures behaved antagonistically . By providing insight into degradation product toxicity and elemental interaction, these experiments demonstrate the utility of employing bioluminescent bacterial assays to investigate biocompatibility of implant materials . Further studies to more closely simulate in vivo conditions, though, are required to fully gauge their potential in this regard.

Int J Dermatol, 1999 Apr, 38(4), 279 - 84
Deep fungal and higher bacterial skin infections in Thailand: clinical manifestations and treatment regimens; Mahaisavariya P et al.; BACKGROUND: Deep fungal and higher bacterial skin infections occur fairly frequently in Thailand . METHODS: Cases with a provisional diagnosis of deep fungal and higher bacterial infections were prospectively collected from 1994 to 1997 in the Granuloma Clinic, Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand . Demographic data, clinical manifestations, causative organisms, histologic features, treatment, and outcome were investigated . RESULTS: The total cases in a 4-year period numbered 27 . The male to female ratio was approximately 1:1 . Mycetoma was most common, followed by chromoblastomycosis . Actinomycetoma was similar in incidence to eumycetoma . The only causative organism that could be identified among the mycetoma cases was Cladosporium carrionii, which caused mycetoma of the buttock of an aplastic anemia patient at the site of bone marrow aspiration . Surgical treatment was recommended for eumycetoma . Chromoblastomycosis was caused by C . carrionii and F . compactum and responded well with itraconazole orally . Mycotic abscesses were found in four cases, basidiobolomycosis in two cases, and cutaneous nocardiosis in one case . Cotrimoxazole was recommended in the treatment of actinomycetoma, cutaneous nocardiosis, and basidiobolomycosis . CONCLUSIONS: Localized, chronic, slow, progressive, and usually asymptomatic were the main cutaneous manifestations of deep fungal and higher bacterial skin infections . A skin biopsy for histologic study and culture identification should be performed in every suspected case . The causative organisms were found in the histologic sections of every case, but only about one-third were found by culture.

Crit Care Med, 1999 Apr, 27(4), 771 - 8
Hemoglobin infusion augments the tumor necrosis factor response to bacterial endotoxin (lipopolysaccharide) in mice; Su D et al.; OBJECTIVE: To determine whether cell-free hemoglobin augments the inflammatory cascade, as detected by production of tumor necrosis factor (TNF) elicited by bacterial endotoxin (lipopolysaccharide {LPS}) . DESIGN: In vivo and ex vivo study, using a mouse model of sepsis . SETTING: Animal research facility SUBJECTS: Female Swiss Webster mice . INTERVENTIONS: For the in vivo experiments, an LD50 dose (500 microg) of Escherichia coli LPS was injected intraperitoneally into mice . Cell-free crosslinked hemoglobin (60 mg/mouse) or saline was administered intravenously 10 hrs before or coincident with LPS . For the ex vivo experiments, hemoglobin (60 mg/mouse) or saline was administered intravenously to mice, and, 10 hrs later, hepatic Kupffer cells, peripheral blood mononuclear cells, or peritoneal macrophages were isolated . MEASUREMENTS AND MAIN RESULTS: Intravenous infusion of hemoglobin either 10 hrs before or coincident with intraperitoneal LPS resulted in a peak of plasma TNF that was greater than in control mice administered LPS only . Cultured Kupffer cells, isolated from mice that had received hemoglobin in vivo 10 hrs before cell collection, produced more TNF in response to LPS in vitro than cells from normal mice . A trend toward greater TNF production in vitro by peripheral blood mononuclear cells obtained from hemoglobin-treated mice also was observed . Enhanced sensitivity to LPS was not observed with cultured peritoneal macrophages from mice that had received hemoglobin . CONCLUSIONS: Intravenous hemoglobin increased the sensitivity of hepatic macrophages to subsequent stimulation by LPS . This effect may contribute to the increased mortality that we have observed in animals that have received both LPS and hemoglobin.

Przegl Epidemiol, 1998, 52(4), 491 - 8
{Complications and sequelae of the purulent, bacterial meningoencephalitis in the material from the 1st Clinic of Infectious Diseases of Silesian Medical Academy in Bytom in the years 1991-1997}; Kepa L et al.; From 1991 to 1997 at the I Clinic of Infectious Diseases of Silesian Medical Academy in Bytom 123 patients with purulent, bacterial meningoencephalitis were treated . Mortality in the analysed group was 28.5% (35 cases) . In the course of disease various complications were observed: seizures (43.1% cases), ischaemic stroke (2.4% cases), brain abscess (4.1%) . Permanent consequences subsequent to the disease were found in 16.3% cases: deafness and partial deafness, psychic disorders, paresis and paralysis, epilepsy and cranial nerves paralysis . Bacterial infections of the central nervous system are still danger diseases producing high lethality, complications and subsequent neurological sequelae.

J Reprod Med, 1999 Apr, 44(4), 359 - 62
Oral metronidazole vs . Metrogel Vaginal for treating bacterial vaginosis . Cost-effectiveness evaluation; Ransom SB et al.; OBJECTIVE: To compare the cost-effectiveness of metronidazole versus Metrogel Vaginal in the treatment of bacterial vaginosis . STUDY DESIGN: Sixty consecutive patients with a clinical diagnosis of bacterial vaginosis were randomly assigned prospectively into either the metronidazole, 500 mg (twice daily for seven days by mouth) or Metrogel Vaginal (one applicator twice daily for five days) treatment group . The study patients were aged 18-30 years, without other medical problems . The patients proceeded with outpatient therapy and returned 7-10 days after the completion of treatment for reevaluation . During the study, patients refrained from sexual relations, avoided alcohol and drugs, and avoided all medication . The physician evaluated the patients for bacterial vaginosis through standard wet preparation, whiff test and pH testing prior to and after treatment . The patients were randomized by a nurse and were blinded for study purposes to the evaluating physician . RESULTS: Successful treatment outcomes for bacterial vaginosis occurred in 27 and 28 patients for Metrogel Vaginal and metronidazole, respectively, out of the original 30 patients in each study group . All patients introduced into the study completed the study without difficulty . No significant complications were found in either treatment group . Three patients treated with metronidazole experienced nausea during the treatment interval . The entire cost of treatment was $19.71 and $1.51 for Metrogel Vaginal and metronidazole, respectively . CONCLUSION: The most cost-effective treatment for bacterial vaginosis was generic metronidazole . While the use of the more expensive Metrogel Vaginal may be reasonable for patients experiencing side effects of oral metronidazole, most patients should be treated with the less expensive generic metronidazole.

Proc Natl Acad Sci U S A, 1999 May 11, 96(10), 5645 - 50
Heat shock protein 90 mediates macrophage activation by Taxol and bacterial lipopolysaccharide; Byrd CA et al.; Taxol, a plant-derived antitumor agent, stabilizes microtubules . Taxol also elicits cell signals in a manner indistinguishable from bacterial lipopolysaccharide (LPS) . LPS-like actions of Taxol are controlled by the lps gene and are independent of binding to the known Taxol target, beta-tubulin . Using biotin-labeled Taxol, avidin-agarose affinity chromatography, and peptide mass fingerprinting, we identified two Taxol targets from mouse macrophages and brain as heat shock proteins (Hsps) of the 70- and 90-kDa families . Geldanamycin, a specific inhibitor of the Hsp 90 family, blocked the nuclear translocation of NF-kappaB and expression of tumor necrosis factor in macrophages treated with Taxol or with LPS . Geldanamycin did not block microtubule bundling by Taxol or macrophage activation by tumor necrosis factor . Thus, Taxol binds Hsps, and Hsp 90 helps mediate the activation of macrophages by Taxol and by LPS.

Immunology, 1999 Mar, 96(3), 404 - 10
Dietary lipids modify the cytokine response to bacterial lipopolysaccharide in mice; Sadeghi S et al.; To investigate the effect of dietary lipids with different fatty acid compositions upon the in vivo cytokine response to bacterial lipopolysaccharide (LPS), mice were fed for 5 weeks on a low-fat diet or on one of four high-fat diets that contained 20%, by weight, of coconut oil (CO), olive oil (OO), safflower oil (SO) or fish oil (FO) . The mice were injected intraperitoneally with a non-lethal dose of Escherichia coli LPS (100 micrograms/20 g body weight) and killed 90 or 180 min later . Plasma tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1alpha, IL-6 and IL-10 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) . Plasma TNF-alpha and IL-10 concentrations were higher 90 min postinjection than after 180 min, whereas plasma IL-1beta and IL-6 concentrations were higher 180 min postinjection than after 90 min . Peak plasma TNF-alpha, IL-1beta and IL-6 concentrations were lower in the CO- and FO-fed mice than in those fed the SO diet . Peak plasma IL-10 concentrations were higher in CO-fed mice than in those fed some of the other diets . These observations suggest that, relative to the n-6 polyunsaturated fatty acid-rich SO diet, CO and FO diminish production of proinflammatory cytokines in vivo . This indicates that these fatty acids might be useful therapies in acute and chronic inflammatory diseases . The enhanced production of IL-10 following CO feeding appears to be an additional antiinflammatory effect of this oil, which could give added benefit in various clinical conditions.

Biochim Biophys Acta, 1999 May 6, 1450(1), 53 - 60
Non-invasive determination of bacterial single cell properties by electrorotation; Holzel R; So far, electrorotation and its application to the determination of single cell properties have been limited to eukaryotes . Here an experimental system is described that allows the recording of electrorotation spectra of single bacterial cells . The small physical dimensions of the developed measuring chamber combined with a single frame video analysis made it possible to monitor the rotation of objects as small as bacteria by microscopical observation despite Brownian rotation and cellular movement . Thus physical properties of distinct organelles of E . coli could be simultaneously determined in vivo at frequencies between 1 kHz and 1 GHz . Experimental data were evaluated following a three-shell model of the cell . Electrical conductivities of cytoplasm and outer membrane were determined to 4.4 mS/cm and 25 microS/cm, respectively, that of the periplasmic space was found to increase with the square root of the medium ionic strength . Specific capacitances of inner and outer membrane amounted to 1.4 microF/cm2 and 0.26 microF/cm2, respectively, the thickness of the periplasm to about 50 nm . Heat treatment of the cells lead to a reduction of cytoplasmic conductivity to 0.9 mS/cm, probably caused by an efflux of ions through the permeabilized inner membrane.

Mol Microbiol, 1999 Apr, 32(2), 357 - 65
Conversion of a bacterial warm sensor to a cold sensor by methylation of a single residue in the presence of an attractant; Nishiyama SI et al.; The aspartate chemoreceptor (Tar) of Escherichia coli also serves as a thermosensor, and it is very amenable to genetic and biochemical analysis of the thermosensing mechanism . Its thermosensing properties are controlled by reversible methylation of the cytoplasmic signalling/adaptation domain of the protein . The unmethylated and the fully methylated (aspartate-bound) receptors sense, as attractant stimuli, increases (warm sensor) and decreases (cold sensor) in temperature respectively . To learn more about the mechanism of thermosensing, we replaced the four methyl-accepting glutamyl residues with non-methylatable aspartyl residues in all possible combinations . In a strain defective in both methyltransferase (CheR) and methylesterase (CheB) activities, all of the mutant Tar proteins functioned as warm sensors . To create a situation in which all of the remaining glutamyl residues were methylated, we expressed the mutant proteins in a CheB-defective, CheR-overproducing strain . The fully glutamyl-methylated proteins were designed to mimic the full range of methylation states possible for wild-type Tar . Almost all of the methylated mutant receptors, including those with single glutamyl residues, were cold sensors in the presence of aspartate . Thus, binding of aspartate to Tar and methylation of its single glutamyl residue can invert its temperature-dependent signalling properties.

Bioelectrochem Bioenerg, 1999 Feb, 48(1), 87 - 93
Studies on the heme and H2-uptake reaction from Azotobacter vinelandii bacterial ferritin; Huang HQ et al.; Bacterial ferritin of Azotobacter vinelandii (AvBF) is directly able to pick electrons up for iron release from or transfer them for storage to a platinum electrode in the absence of mediator or other reducer . The ferritin containing the structure of heme-Co2+ in part shows weakened activity to electrode and decreases the rate of iron release greatly . A reversible reduction process of the ferritin is observed by the spectral change regularly ranging from 310 to 260 nm under mixed gases containing 98% H2 and 2% to O2 . The activity of nitrogen fixation from the whole cell of A . vinelandii increases greatly by H2 reduction with potentials ranging from -397 to -425 mV vs . NHE, indicating two important roles of H2-uptake reaction of the ferritin in increasing activity of nitrogen fixation and in supplying iron to synthesize nitrogenase.

Food Chem Toxicol, 1999 Feb-Mar, 37(2-3), 117 - 23
Application of in vitro methods using peripheral whole blood to selecting highly susceptible individuals among common squirrel monkeys (Saimiri sciureus) to bacterial lipopolysaccharides; Yamaguchi F et al.; The present study was designed to elucidate whether the individual susceptibility of common squirrel monkeys (Saimiri sciureus) to bacterial lipopolysaccharides (LPS) can be predicted by in vitro testing batteries performed in advance . Of the in vitro tests, the blastogenic response (n = 11) to LPS was determined by a micro-blood culture technique, and the production (n = 6) of cytokines such as tumour necrosis factor (TNF-alpha), interleukin-1 (IL-1beta) and interleukin-6 (IL-6) released into the culture medium was measured with an enzyme-linked immunosolvent assay (ELISA) . In the blastogenic assay, four out of 11 animals showed an increase in the uptake of {3H}thymidine in a concentration-dependent manner (LPS-positive reaction), while seven remaining animals did not show any response to LPS (LPS-negative reaction) . Among the cytokines employed, an elevation in TNF-alpha production was noted in three out of six animals employed without affecting IL-1beta and IL-6 productions . After the completion of in vitro examinations, LPS was administered subcutaneously at 0.3 mg/kg to these animals (n = 11) for 14 consecutive days . The six monkeys including either four animals showing a LPS-positive reaction or three animals having an increase in TNF-alpha production exhibited moribund conditions from days 3 to 12, and five remaining monkeys including five animals showing a LPS-negative reaction or three animals having a decrease in TNF-alpha production survived . The extrapolation rate from the in vitro data to the in vivo results was over 80% (9/11) and 100% (6/6) in the blastogenic assay and TNF-alpha production, respectively . These results demonstrate that the in vitro methods can be available to selection of LPS-sensitive squirrel monkeys in advance.

J Biomater Sci Polym Ed, 1999, 10(4), 483 - 99
Hydrolytic and enzymatic incubation of polyhydroxyoctanoate (PHO): a short-term in vitro study of a degradable bacterial polyester; Marois Y et al.; The present study examined the degradation behaviour of poly(beta-hydroxy octanoate) (PHO), a bacterial poly(beta-hydroxy alkanoate), following incubation under hydrolytic or enzymatic conditions in vitro . Solution-cast PHO films were incubated in a citrate buffer solution with and without acid phosphatase and in an acetate buffer with and without beta-glucuronidase for periods ranging from 7 to 60 days . The physical characterization of the PHO films was analyzed by SEM and tensile strength studies . In addition, various analytical methods were used to detect modifications in the chemical and morphological structure of the PHO, namely, ESCA, FTIR, DSC, X-ray diffraction, and SEC . The results indicate that the enzymatic conditions selected in the present study induced no significant surface morphological or chemical modifications, and no significant weight loss was observed after 60 days of incubation . However, as revealed by weight average molecular weight Mw and number average molecular weight Mn decreases, changes in the bulk structure of the PHO were observed with acid phosphatase at 28 and 60 days, in contrast to smaller Mw and Mn decreases recorded in both the buffers and the beta-glucuronidase . The tensile properties had decreased following incubation, yet showed no difference under all of the selected conditions . With no weight loss or surface changes, the PHO films incubated in acid phosphatase showed only a chemical hydrolytic process characterized by Mw and Mn decreases with time of incubation . The present study demonstrated that the degradation of PHO films is one of slow, chemical hydrolysis only, perhaps requiring several months of incubation . The hydrophobic nature of the long alkyl pendent chain in PHO may be responsible for this slow process . The inability of enzymes to degrade PHO may be attributed to the latter's poor adsorption capacity, due to its hydrophobic nature, and to a lack of specificity in the catalytic activity of these enzymes.

Int J Urol, 1999 Mar, 6(3), 130 - 4
Role of ejaculation in the treatment of chronic non-bacterial prostatitis; Yavascaoglu I et al.; BACKGROUND: Chronic non-bacterial prostatitis (NBP) is the most common prostatitis syndrome . Prevention and cure are not possible because the cause of NBP is unknown . However, patients may benefit from supportive measures . The impact of the frequency of ejaculation alone on the course of NBP was evaluated in the present study . METHODS: Thirty-four single male patients who avoided masturbation and extramarital sexual intercourse for personal and/or religious beliefs and who did not respond to a clinical trial of doxycycline hydrochloride therapy (200 mg daily for 4 weeks) directed against mycoplasmas, chlamydiae and ureaplasmas were enrolled in the study . They were encouraged to masturbate regularly at least twice a week and were re-evaluated at the end of a 6 month period, including a complete inquiry regarding their sexual function during this time . Response was assessed by a symptom severity index . RESULTS: Clinical and laboratory re-evaluation could be performed in 28 patients . Of 18 patients who adhered to the recommendations, two (11%) experienced complete relief of symptoms, whereas six (33%) had marked improvement, six had moderate improvement and four (22%) did not benefit . In contrast, three of seven patients who masturbated less frequently reported partial improvement . Three patients who did not ejaculate other than during wet dreams had a worse prognosis . CONCLUSIONS: Young men who are single and suffering from NBP must be informed about their illness in detail and, if they are not doing so, they should be encouraged to ejaculate regularly, for example by masturbation in the absence of a sexual relationship with a partner . We believe that normal sexual activity decreases the incidence of NBP in some cases.

Int Arch Allergy Immunol, 1999 Feb-Apr, 118(2-4), 457 - 61
Bacterial DNA and CpG-containing oligodeoxynucleotides activate cutaneous dendritic cells and induce IL-12 production: implications for the augmentation of Th1 responses; Jakob T et al.; BACKGROUND: Unmethylated CpG sequences in bacterial DNA act as adjuvants selectively inducing Th1 predominant immune responses during genetic vaccination or when used in conjunction with protein Ag . The precise mechanism of this adjuvant effect is unknown . Because dendritic cells (DC) are thought to be crucially involved in T cell priming and Th1/Th2 education during vaccination via skin, we characterized the effects of bacterial DNA and CpG-containing oligodeoxynucleotides (CpG ODN) on cutaneous DC . METHODS AND RESULTS: Stimulation with CpG ODN 1826 (6 micrograms/ml) induced activation of immature Langerhans cell (LC)-like DC as determined by an increased expression of MHC class II and costimulatory molecules, loss of E-cadherin-mediated adhesion and increased ability to stimulate allogeneic T cells . Composition-matched control ODN 1911 lacking CpG sequences at equal concentrations was without effect . In comparison to LPS and ODN 1911, CpG ODN 1826 selectively stimulated DC to release large amounts of IL-12 (p40) and little IL-6 or TNF-alpha within 18 h and detectable levels of IL-12 p70 within 72 h . Stimulation with Escherichia coli DNA, but not calf thymus DNA, similarly induced DC maturation and IL-12 p40 production . Injection of CpG ODN into murine dermis induced enhanced expression of MHC class II and CD86 by LC in the overlying epidermis and intracytoplasmic IL-12 p40 accumulation in a subpopulation of activated LC . CONCLUSION: Bacterial DNA and CpG ODN stimulate DC in vitro and in vivo and may preferentially elicit Th1-predominant immune responses because they can activate and mobilize DC, inducing them to produce IL-12.

Scand J Infect Dis, 1998, 30(6), 591 - 6
Bacterial or crystal-associated arthritis? Discriminating ability of serum inflammatory markers; Soderquist B et al.; A retrospective study of patients with culture-verified septic arthritis (n = 54) and polarizing microscopy verified crystal-associated arthritis (n = 34) was conducted with the objective to identify discriminating laboratory parameters in serum . Serum CRP levels (p = 0.002) and ESR (p = 0.03) were significantly higher on admission in patients with septic arthritis than in those with crystal-associated arthritis . The peripheral WBC counts did not differ between the two groups, nor did the lactoferrin or procalcitonin (PCT) levels . Serum TNFalpha concentrations on admission were higher in patients with septic arthritis than in those with crystal-associated arthritis (p = 0.0008) . Significant differences were also found for IL-8 (p = 0.01) and G-CSF (p = 0.002), but not for IL-6 (p = 0.5) . However, extensive overlap between the groups was present, resulting in low sensitivity, specificity and predictive value for each test . Determining serum levels of acute phase reactants, including cytokines, does not replace careful synovial fluid examination, including direct microscopy and cultivation.

Eur J Anaesthesiol, 1999 Mar, 16(3), 169 - 75
Effects of endothelin-1 on bacterial clearance in rabbits; Schmeck J et al.; As elevated endothelin-1 (ET-1) levels have been reported in systemic inflammatory diseases, the role of ET-1 as a promoter of inflammatory reactions is currently under investigation . The purpose of this study was to investigate the potential influence of ET-1 on systemic vascular pressure and immune function in terms of blood clearance and organ distribution of injected Escherichia coli in a rabbit model . To enable quantification of the clearance process, defined numbers of exogenous E . coli (10(8) cfu) were injected intravenously 60 min after starting the infusion of ET-1 (0.2 microgram kg-1 min-1; n = 9) or after saline infusion (controls, n = 9) . Parameters monitored were arterial blood pressure, airway pressure, serum lactate concentrations and rates of bacterial elimination from the blood . At 180 min after E . coli injection, the animals were killed, and tissue samples of liver, kidney, spleen and lung were collected for bacterial counts . ET-1 infusion produced an increase in mean arterial pressure (83.9 +/- 3.9 mmHg vs . 50.1 +/- 4.1 mmHg at 120 min; P < 0.01) associated with higher serum lactate concentrations (12.6 +/- 1.3 vs . 5.4 +/- 0.3 mg dL-1; P < 0.001) and a delayed bacterial elimination from the blood compared with controls . Furthermore, there was increased colonization of the lungs (3.6 +/- 0.5 x 10(3) cfu vs . 745 +/- 120 cfu; P < 0.01), spleen (142.4 +/- 45.4 x 10(3) cfu vs . 227 +/- 5.2 x 10(3) cfu; P < 0.05) and kidney (758 +/- 329 vs . 357 +/- 151 cfu; NS), reflecting a reduced bacterial killing function.

Alaska Med, 1999 Jan-Mar, 41(1), 3 - 7
Palinopsia with bacterial brain abscess and Noonan syndrome; Arnold RW et al.; Though positive visual symptoms can be psychological in nature, or can result from a perceptive or anxious patients recognizing optical principals in the eye itself, this case illustrates how a thorough history is required to delineate those rarer signs which accompany serious macular or neuro-ophthalmic pathology.

J Biol Chem, 1999 May 7, 274(19), 13223 - 8
Co-translocation of a periplasmic enzyme complex by a hitchhiker mechanism through the bacterial tat pathway; Rodrigue A et al.; Bacterial periplasmic nickel-containing hydrogenases are composed of a small subunit containing a twin-arginine signal sequence and a large subunit devoid of an export signal . To understand how the large subunit is translocated into the periplasm, we cloned the hyb operon encoding the hydrogenase 2 of Escherichia coli, constructed a deletion mutant, and studied the mechanism of translocation of hydrogenase 2 . The small subunit (HybO) or the large subunit (HybC) accumulated in the cytoplasm as a precursor when either of them was expressed in the absence of the other subunit . Therefore, contrary to most classical secretory proteins, the signal sequence of the small subunit itself is not sufficient for membrane targeting and translocation if the large subunit is missing . On the other hand, the small subunit was required not only for membrane targeting of the large subunit, but also for the acquisition of nickel by the large subunit . Most interestingly, the signal sequence of the small subunit determines whether the large subunit follows the Sec or the twin-arginine translocation pathway . Taken together, these results provide for the first time compelling evidence for a naturally occurring hitchhiker co-translocation mechanism in bacteria.

Int J Parasitol, 1999 Feb, 29(2), 357 - 64
Effects of tetracycline on the filarial worms Brugia pahangi and Dirofilaria immitis and their bacterial endosymbionts Wolbachia; Bandi C et al.; Wolbachia endosymbiotic bacteria have been shown to be widespread among filarial worms and could thus play some role in the biology of these nematodes . Indeed, tetracycline has been shown to inhibit both the development of adult worms from third-stage larvae and the development of the microfilaraemia in jirds infected with Brugia pahangi . The possibility that these effects are related to the bacteriostatic activity of tetracycline on Wolbachia symbionts should be considered . Here we show that tetracycline treatment is very effective in blocking embryo development in two filarial nematodes, B . pahangi and Dirofilaria immitis . Embryo degeneration was documented by TEM, while the inhibition of the transovarial transmission of Wolbachia was documented by PCR . Phylogenetic analysis on the ssrDNA sequence of the Wolbachia of B . pahangi confirms that the phylogeny of the bacterial endosymbionts is consistent with that of the host worms . The possibility that tetracycline inhibition of embryo development in B . pahangi and D . immitis is determined by cytoplasmic incompatibility is discussed.

FEMS Microbiol Lett, 1999 Apr 1, 173(1), 231 - 8
Functional conservation between the argininosuccinate lyase of the archaeon Methanococcus maripaludis and the corresponding bacterial and eukaryal genes; Cohen-Kupiec R et al.; The argH gene encoding argininosuccinate lyase (ASL) of Methanococcus maripaludis was cloned on a 4.7-kb HindIII genomic fragment . The gene is preceded by a short open reading frame (ORF149), which encodes a polypeptide with an unknown function . The two genes are co-transcribed . The ASL of M . maripaludis shares a high amino acid identity with ASLs from both bacterial and eukaryal origins and was able to complement both an argH Escherichia coli mutant and an arg4 yeast mutant, showing its extraordinary evolutionary conservation . Attempts to create an argH auxotroph of M . maripaludis by disrupting the genomic allele were unsuccessful: although a knockout allele of argH was integrated into the M . maripaludis chromosome by homologous recombination, the intact copy was not excluded, suggesting that the argH gene is essential.

Microbiology, 1999 Apr, 145 ( Pt 4), 973 - 83
Transport of EDTA into cells of the EDTA-degrading bacterial strain DSM 9103; Witschel M et al.; In the bacterial strain DSM 9103, which is able to grow with the complexing agent EDTA as the sole source of carbon, nitrogen and energy, the transport of EDTA into whole cells was investigated . EDTA uptake was found to be dependent on speciation: free EDTA and metal-EDTA complexes with low stability constants were readily taken up, whereas those with stability constants higher than 1016 were not transported . In EDTA-grown cells, initial transport rates of CaEDTA showed substrate-saturation kinetics with a high apparent affinity for CaEDTA (affinity constant Kt= 0.39 microM) . Several uncouplers had an inhibitory effect on CaEDTA transport . CaEDTA uptake was also significantly reduced in the presence of an inhibitor of ATPase and the ionophore nigericin, which dissipates the proton gradient . Valinomycin, however, which affects the electrical potential, had little effect on uptake, indicating that EDTA transport is probably driven by the proton gradient . Of various structurally related compounds tested only Ca2+-complexed diethylenetriaminepentaacetate (CaDTPA) competitively inhibited CaEDTA transport . Uptake in fumarate-grown cells was low compared to that measured in EDTA-grown bacteria . These results strongly suggest that the first step in EDTA degradation by strain DSM 9103 consists of transport by an inducible energy-dependent carrier . Uptake experiments with 45Ca2+ in the presence and absence of EDTA indicated that Ca2+ is transported together with EDTA into the cells . In addition, these transport studies and electron-dispersive X-ray analysis of electron-dense intracellular bodies present in EDTA-grown cells suggest that two mechanisms acting simultaneously allow the cells to cope with the large amounts of metal ions taken up together with EDTA . In one mechanism the metal ions are excreted, in the other they are inactivated intracellularly in polyphosphate granules.

Electrophoresis, 1999 Mar, 20(3), 458 - 61
Mice immunization with gel electrophoresis-micropurified bacterial lipopolysaccharides; Pupo E et al.; Some evidence on the possible use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to elicit antibodies against smooth- or rough-type bacterial lipopolysaccharides (LPS) is shown . Gel-separated LPS were negatively stained with zinc-imidazole to precisely localize the bands of interest under fully reversible conditions . Then the bands of interest were excised and the resulting gel slices washed in a solution of a zinc-complexing agent (e.g., 100 mM EDTA), after which they were extruded through a metal sieve of 32 microm average size contained in a 1 mL syringe, to generate homogeneous gel microparticles . The LPS-containing gel slurries were used directly to immunize female BALB/c mice . Using this procedure, positive mouse polyclonal antibody responses against gel-purified smooth- or rough-LPS forms from Escherichia coli K-235 or Bordetella pertussis were elicited, as tested by a dot-immunoblotting assay . Our results may encourage the use of SDS-PAGE-micropurified LPS to develop optimized immunization procedures for the generation of specific antibodies against LPS bands of defined sizes, and therefore they constitute an intermediate step toward that aim.

Trends Biochem Sci, 1999 Mar, 24(3), 104 - 9
Bacterial solutions to the iron-supply problem; Braun V et al.; The insolubility of Fe3+ necessitates special mechanisms for iron acquisition in most organisms . Bacteria use siderophores to chelate Fe3+ and iron in heme, hemoglobin, transferrin and lactoferrin, and employ novel mechanisms for receptor-dependent iron transport and iron-regulated gene expression . These mechanisms involve transfer of energy from the cytoplasmic membrane to the outer membrane to drive active transport and might induce transcription of transport genes by transmitting a signal from the cell surface.

Eur J Biochem, 1999 Apr, 261(2), 468 - 74
Preferential degradation of polyadenylated and polyuridinylated RNAs by the bacterial exoribonuclease polynucleotide phosphorylase; Lisitsky I et al.; Polyadenylation of mRNA has been shown to target the RNA molecule for rapid exonucleolytic degradation in bacteria . To elucidate the molecular mechanism governing this effect, we determined whether the Escherichia coli exoribonuclease polynucleotide phosphorylase (PNPase) preferably degrades polyadenylated RNA . When separately incubated with each molecule, isolated PNPase degraded polyadenylated and non-polyadenylated RNAs at similar rates . However, when the two molecules were mixed together, the polyadenylated RNA was degraded, whereas the non-polyadenylated RNA was stabilized . The same phenomenon was observed with polyuridinylated RNA . The poly(A) tail has to be located at the 3' end of the RNA, as the addition of several other nucleotides at the 3' end prevented competition for polyadenylated RNA . In RNA-binding experiments, E . coli PNPase bound to poly(A) and poly(U) sequences with much higher affinity than to poly(C) and poly(G) . This high binding affinity defines poly(A) and poly(U) RNAs as preferential substrates for this enzyme . The high affinity of PNPase for polyadenylated RNA molecules may be part of the molecular mechanism by which polyadenylated RNA is preferentially degraded in bacterial cells.

Int J STD AIDS, 1999 Feb, 10(2), 93 - 7
A comparison of the use of Papanicolaou-stained cervical cytological smears with Gram-stained vaginal smears for the diagnosis of bacterial vaginosis in early pregnancy; Lamont RF et al.; Our objective is to compare the efficacy of using Papanicolaou (PAP)-stained cervical cytology smears with a standardized method of interpreting Gram-stained vaginal smears for the diagnosis of bacterial vaginosis (BV) in pregnancy . High vaginal smears were Gram-stained and examined by a single observer to characterize 3 grades of vaginal flora and diagnose BV . Cervical smears were PAP-stained and examined for characteristic patterns of vaginal flora including evidence of BV by either a number of cytotechnicians or a single cytopathologist . The results of the 2 methods were compared . Seven hundred and forty-seven women attending an antenatal clinic in a district general hospital who consented to have a smear of vaginal secretions and cervical cytology in early pregnancy . The main outcome measure is the diagnosis of BV by different methods in a pregnant population . Compared with the Gram-stain method for the diagnosis of BV, there was good agreement between PAP-stain interpretation by a single observer but the agreement was not as good with PAP-stain interpretation by multiple cytotechnicians . When the grades were consolidated to normal (grade I) and abnormal flora (grades II and III), compared to Gram-stained smears, PAP cytology undertaken by several cytotechnicians had a sensitivity of 80.7% and a specificity of 90.7% . The sensitivity and specificity increased to 87% and 97%, respectively, when the PAP-stained smears were read by a single cytopathologist . Using kappa scores, only those readings made by a single cytopathologist were reliable . The setting in a cytopathology laboratory comprises multiple cytotechnicians, so that PAP-stain analysis of vaginal smears for the diagnosis of BV is likely to provide results which are less reliable than those obtained by Gram staining . The latter should be the first choice and every effort should be made to set up this service.

Obstet Gynecol, 1999 Apr, 93(4), 517 - 22
Risk scoring, fetal fibronectin, and bacterial vaginosis to predict preterm delivery; Crane JM et al.; OBJECTIVE: To determine the value of markers for predicting spontaneous preterm birth . METHODS: One hundred forty asymptomatic gravidas were recruited from 20-24 weeks' gestation . Risk score was assessed, vaginal swabs were analyzed for bacterial vaginosis, and cervical and vaginal swab were tested for fetal fibronectin FDC-6, X18A4, and CAF . Univariate analysis was used to determine potential predictors (and combinations of predictors) of outcome . Multiple logistic regression was done to identify independent predictors of spontaneous preterm birth . Sensitivity, specificity, positive and negative predictive values; and odds and likelihood ratios were calculated for significant predictors . RESULTS: Predictors significantly associated with the primary outcome were preterm birth-risk score and vaginal fetal fibronection FDC-6 (logistic regression odds ratio {OR} 16.9 {95% confidence interval (CI) 3.1, 92.8}) and 8.0 ({95% CI 1.6, 38.2}, respectively) . Bacterial vaginosis, fetal fibronectin X18A4, fibronectin CAF, and cervical fetal fibronectin FDC-6 were not associated with spontaneous preterm birth; however, the statistical power to assess these variables was limited . The combination of positive preterm birth-risk score and vaginal fetal fibronectin FDC-6 had a sensitivity of 44.4%, specificity of 97.7%, positive predictive value of 57.1%, negative predictive value of 96.2%, and a significant likelihood ratio for a positive test of 19.4 (95% CI 5.1, 73.8) . CONCLUSION: The combination of preterm birth-risk score and vaginal fetal fibronectin FDC-6 predicted spontaneous preterm birth . Intervention trials are required to determine whether a combination of screening tests will reduce rates of spontaneous preterm birth.

J Investig Allergol Clin Immunol, 1999 Jan-Feb, 9(1), 6 - 13
Bacterial infection as an important triggering factor in bronchial asthma; Oehling AK; It is very surprising that in recent decades, the bacterial infection factor has been so overlooked in the causal treatment of bronchial asthma . Emphasis is put in the viral infection, but the bacterial infection usually associated with it is ignored . In several publications, we have insisted on the importance of the bacterial infection factor in the etiopathogenesis of bronchial asthma . It is alarming that even in the international consensus on its treatment this aspect is overlooked . In the first decades of this century, great importance had already been put on bacterial infection in the triggering of bronchospasm . In this review, we insist on this role of bacterial infection, which comes as a result of our extensive experience in this area, and the fact that in the last 10 years many authors have proven its responsibility at a bronchial mucosa level . In due time, we may be able to prove that the bacterial antigens can potentiate the action of inhalant allergens . Some authors have even proven that the action of these bacterial antigens even more energetically increases the number of intraepithelial dendritic cells in the bronchial mucosa after inhalation of bacterial lipopolysaccharide . Bystander respiratory bacterial infections can also directly modulate T helper 1 and 2 selection parallel to the immune response to inhalant allergens . Recent studies have also proven that in respiratory infection, bacterial antigens hold the main responsibility in the inflammatory and bronchospastic response in the etiopathogenesis of bronchial asthma . Therefore, a consequent treatment of the infection is required, by means of wide spectrum antibiotics, as well as prescription of bacterial immunotherapy, as we have emphasized on other occasions . In conclusion, we must try to cure asthmatic patients and not to maintain them with inhalers and unnecessary corticosteroid therapy, since increasing reactions to corticosteroids are witnessed every day.

Clin Ther, 1999 Feb, 21(2), 340 - 52
Comparison of sparfloxacin and clarithromycin in the treatment of acute bacterial maxillary sinusitis . Sparfloxacin Multicenter AMS Study Group; Henry DC et al.; Five hundred four patients were enrolled in a randomized, double-masked, multicenter study comparing the efficacy and tolerability of a 10-day regimen of sparfloxacin with a 14-day regimen of clarithromycin in the treatment of acute maxillary sinusitis . Two hundred fifty-two patients received sparfloxacin as a single 400-mg dose on day 1 and 200 mg once daily for 9 additional days, and 252 patients received clarithromycin 500 mg twice daily for 14 days . In the all-treated population, clinical success was observed at 6 to 10 days after therapy in approximately 82% of the patients in each treatment group . A total of 430 patients met the inclusion criteria for clinical assessment . The success rates in these patients were also comparable, at 83.1% and 83.4% for the sparfloxacin and clarithromycin groups, respectively . Sustained clinical success rates in the all-treated population 3 to 4 weeks after therapy were 71.6% for the sparfloxacin group and 68.6% for the clarithromycin group . All treated patients were included in the tolerability analysis . The frequency of adverse events in the clarithromycin and sparfloxacin groups was 57.9% and 48.4%, respectively . The most frequently noted adverse events were diarrhea, photosensitivity reaction, taste perversion, nausea, and abdominal pain; >96% of adverse events in the sparfloxacin group and 94% of adverse events in the clarithromycin group were of mild or moderate severity . Among adverse events at least possibly related to study drug, photosensitivity reaction was more common in the sparfloxacin group (9.5% vs . 0.4%), whereas taste perversion (8.7% vs . 0.8%) and abdominal pain (3.6% vs . 1.6%) were more common in the clarithromycin group . Thus the sparfloxacin's more convenient regimen was as effective as clarithromycin in the treatment of acute bacterial maxillary sinusitis, and the overall frequency of adverse events with sparfloxacin was comparable to that with clarithromycin.

Mol Microbiol, 1999 Mar, 31(6), 1611 - 8
Termination of DNA replication of bacterial and plasmid chromosomes; Bussiere DE et al.; Sequence-specific replication termini occur in many bacterial and plasmid chromosomes and consist of two components: a cis-acting ter site and a trans-acting replication terminator protein . The interaction of a terminator protein with the ter site creates a protein-DNA complex that arrests replication forks in a polar fashion by antagonizing the action of the replicative helicase (thereby exhibiting a contrahelicase activity) . Terminator proteins also arrest RNA polymerases in a polar fashion . Passage of an RNA transcript through a terminus from the non-blocking direction abrogates replication termination function, a mechanism that is likely to be used in conditional termini or replication check points.

Biochim Biophys Acta, 1999 Apr 14, 1418(1), 117 - 26
Water transport by the bacterial channel alpha-hemolysin; Paula S et al.; This study is an investigation of the ability of the bacterial channel alpha-hemolysin to facilitate water permeation across biological membranes . alpha-Hemolysin channels were incorporated into rabbit erythrocyte ghosts at varying concentrations, and water permeation was induced by mixing the ghosts with hypertonic sucrose solutions . The resulting volume decrease of the ghosts was followed by time-resolved optical absorption at pH 5, 6, and 7 . The average single-channel permeability coefficient of alpha-hemolysin for water ranged between 1.3x10-12 cm/s and 1.5x10-12 cm/s, depending on pH . The slightly increased single-channel permeability coefficient at lower pH-values was attributed to an increase in the effective pore size . The activation energy of water transport through the channel was low (Ea=5.4 kcal/mol), suggesting that the properties of water inside the alpha-hemolysin channel resemble those of bulk water . This conclusion was supported by calculations based on macroscopic hydrodynamic laws of laminar water flow . Using the known three-dimensional structure of the channel, the calculations accurately predicted the rate of water flow through the channel . The latter finding also indicated that water permeation data can provide a good estimate of the pore size for large channels.

J Neuroimaging, 1999 Apr, 9(2), 78 - 84
Cranial magnetic resonance imaging findings in bacterial endocarditis: the neuroimaging spectrum of septic brain embolization demonstrated in twelve patients; Bakshi R et al.; Infective endocarditis (IE) is an elusive systemic disorder that is often associated with neurologic complications . The contribution of brain magnetic resonance imaging (MRI) to the diagnosis of IE and the spectrum of such findings has been only sparsely described previously . The authors report cranial MRI findings in 12 patients with IE . Each of the patients had MRI evidence of cerebral embolization, with multiple brain lesions noted in most patients (n = 10) . Cortical branch infarction was the most common lesion (n = 8), which usually involved the distal middle cerebral artery tree . The next most common finding (n = 7) was numerous small embolic lesions which typically lodged in the supratentorial gray-white junction, some of which were clinically silent and many of which enhanced (probable microabscesses) . Brain hemorrhages were noted in four patients, most commonly subarachnoid hemorrhage (n = 3) . Two patients developed multiple frank parenchymal macroabscesses/cerebritis lesions . A previously unreported finding in septic embolization, a stroke that became infected with abscess formation ("septic infarction"), was noted in two patients . MRI showed orbital cellulitis in two patients . Most patients studied with gadolinium showed enhancement of lesions (n = 5/8) . The authors conclude that cranial MRI may be a valuable tool in the evaluation of patients with IE . The presence of characteristic cranial MRI lesions, especially of multiple types, may prompt early diagnosis and treatment.

Novartis Found Symp, 1999, 221, 38 - 50; discussions 50-4
pH sensing in bacterial chemotaxis; Levit MN et al.; Bacteria are able to sense a broad range of chemical and energetic stimuli and modulate their swimming behaviour to migrate to more favourable environments . Signal transduction in bacterial chemotaxis is mediated by a two-component system composed of a protein histidine kinase, CheA, and a response regulator, CheY . The phosphorylated response regulator, P approximately CheY, binds to a protein at the flagellar motor, FliM, to cause reversals in flagellar motor rotation . The level of P approximately CheY is controlled by the activity of the kinase CheA, which is in turn regulated by membrane receptors at the cell surface . Membrane receptors such as the aspartate receptor, Tar, are composed of two distinct regions: an extracellular sensing domain that binds stimulatory ligands, aspartate in the case of Tar; and an intracellular signalling domain that forms a complex with the protein kinase CheA . What is the mechanism of transmembrane signalling? How does aspartate binding to the sensing domain at the outside surface of the membrane translate into a change in kinase activity at the membrane cytosol interface? Recent results suggest that the mechanism depends on perturbations in lateral packing within an extensive array of receptors localized to patches at the cell poles . Receptor patching appears to depend on higher-order associations with the kinase CheA as well as an adaptor protein, CheW . It is difficult to assess the locus of pH effects within the context of even a simple signal transduction system like that involved in bacterial chemotaxis . Previous results with mutant strains have indicated that the serine receptor, Tsr, is critical for pH sensing, but in vitro results do not support such a straightforward interpretation of the genetic data.

Novartis Found Symp, 1999, 221, 4 - 14, discussion 14-8
Problems of adverse pH and bacterial strategies to combat it; Dilworth MJ et al.; This chapter aims to survey the problems faced by bacteria found in environments of adverse pH, to review strategies used to combat those problems and to ask how those strategies are implemented . At acid or alkaline pH, bacteria are challenged not just by excess of H+ or OH- but also by excess of metal ions (aluminium, heavy metals at acidic pH, Na+ at alkaline pH), as well as shortages . Bacteria attempt to maintain their intracellular pH by minimizing membrane permeability to H+ and other ions, buffering the cytoplasm, ameliorating the external pH through catabolism or selective substrate utilization, and developing ionic pumping systems . The amelioration of pH depends on the availability of substrate, and is unlikely in most naturally stressful environments . Ion pumping is expensive energetically, although the cost to growth is unknown . The response to adverse pH involves sensing systems and responsive regulatory systems . The adaptive acid tolerance response is now well known in and other bacteria, but is there a widespread adaptive alkali tolerance response? What and where are the sensors? Whether they sense intracellular pH, extracellular pH or delta pH is unclear, although an external sensory input seems essential . Is there one major sensory system responsive to pH or multiple systems with back-up mechanisms? What and where are the regulators? Is there one central regulator controlling all the responses or are there cascades of responses?

Plant J, 1999 Mar, 17(5), 581 - 7
Digital mapping of bacterial artificial chromosomes by fluorescence in situ hybridization; Jackson SA et al.; The bacterial artificial chromosome (BAC) has become the most popular tool for cloning large DNA fragments . The inserts of most BAC clones average 100-200 kilobases (kb) and molecular characterization of such large DNA fragments is a major challenge . Here we report a simple and expedient technique for physical mapping of BAC inserts . Individual BAC molecules were immobilized on glass slides coated with Poly-L-lysine . The intact circular BAC molecules were visualized by fluorescence in situ hybridization using BAC DNA as a probe . The 7.4 kb BAC vector was extended to approximately 2.44 kb per micrometer . Digitally measured linear distances can be transformed into kilobases of DNA using the extension of BAC vector as a standard calibration . We mapped DNA fragments as small as 2 kb directly on circular BAC molecules . A rice BAC clone containing both tandem and dispersed repeats was analyzed using this technique . The distribution and organization of the different repeats within the BAC insert were efficiently determined . The results showed that this technique will be especially valuable for characterizing BAC clones that contain complex repetitive DNA sequences.

EMBO J, 1999 Apr 15, 18(8), 2021 - 30
The crystal structure of a novel bacterial adenylyltransferase reveals half of sites reactivity; Izard T et al.; Phosphopantetheine adenylyltransferase (PPAT) is an essential enzyme in bacteria that catalyses a rate-limiting step in coenzyme A (CoA) biosynthesis, by transferring an adenylyl group from ATP to 4'-phosphopantetheine, yielding dephospho-CoA (dPCoA) . Each phosphopantetheine adenylyltransferase (PPAT) subunit displays a dinucleotide-binding fold that is structurally similar to that in class I aminoacyl-tRNA synthetases . Superposition of bound adenylyl moieties from dPCoA in PPAT and ATP in aminoacyl-tRNA synthetases suggests nucleophilic attack by the 4'-phosphopantetheine on the alpha-phosphate of ATP . The proposed catalytic mechanism implicates transition state stabilization by PPAT without involving functional groups of the enzyme in a chemical sense in the reaction . The crystal structure of the enzyme from Escherichia coli in complex with dPCoA shows that binding at one site causes a vice-like movement of active site residues lining the active site surface . The mode of enzyme product formation is highly concerted, with only one trimer of the PPAT hexamer showing evidence of dPCoA binding . The homologous active site attachment of ATP and the structural distribution of predicted sequence-binding motifs in PPAT classify the enzyme as belonging to the nucleotidyltransferase superfamily.

Rinsho Shinkeigaku, 1998 Oct-Nov, 38(10-11), 931 - 5
{Brain infarct due to non-bacterial thrombotic valvular vegetation associated with primary antiphospholipid antibodies--a case report}; Hino H et al.; A 50-year-old woman with antiphospholipid antibody syndrome (APAS) awoke in a morning to notice dizziness, so she came to our hospital . Several hours later she developed left oculomotor paralysis . Further two hours later she developed right oculomotor paralysis and could not stand . Brain MRI showed high signal intensity lesion of paramedian thalamic and midbrain on the T2-weighted image . Cerebral angiography did not reveal any occlusion . Transesophageal echocardiography disclosed mitral valvular vegetation . We thought this valvular abnormality was non-bacterial thrombotic vegetation associated with APAS and this suggests that cerebral infarction was due to emboli from this vegetation.

Inflamm Res, 1999 Feb, 48(2), 67 - 74
Dose-dependence of bacterial lipopolysaccharide (LPS) effects on peak response and time course of the immune-endocrine host response in humans; Vedder H et al.; OBJECTIVE AND DESIGN: Dose-dependence of lipopolysaccharide (LPS) effects on peak and time course parameters of the immune-endocrine host response was examined in a placebo-controlled design . SUBJECTS: Data from 42 male volunteers were included . TREATMENT: 0.4 or 0.8 ng LPS/kg body weight were applied at 7.00 p.m . METHODS: Body temperature, heart rate and leukocyte counts were quantified . Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), adrenocorticotropic hormone (ACTH), cortisol and human growth hormone (hGH) were measured . RESULTS: LPS increased significantly the levels of immune (TNF-alpha, IL-6) and endocrine (ACTH, cortisol) parameters . HGH secretion was advanced without changes in the total amount of hGH released . Dose-dependence of endotoxin's effects was significant for neuroendocrine (cortisol) and physiological (temperature, heart rate) parameters . Examination of time course parameters demonstrated that the higher dose of endotoxin prolonged the increases in temperature, IL-6 and cortisol levels . CONCLUSIONS: Our data show that increases in the dosage of LPS lead to differential peak responses and changed time course patterns of the human host response.

Eur J Nucl Med, 1999 Apr, 26(4), 333 - 41
Uptake of positron emission tomography tracers in experimental bacterial infections: a comparative biodistribution study of radiolabeled FDG, thymidine, L-methionine, 67Ga-citrate, and 125I-HSA; Sugawara Y et al.; The purpose of this study was to evaluate the localization of positron emission tomography (PET) tracers {2-deoxy-2-fluoro-D-glucose (FDG), thymidine, and L-methionine} in sites of bacterial infection, and to contrast this with that of other tracers . The left calf muscles of rats were infected with a suspension of Escherichia coli and the biodistribution of 18F- or 3H-FDG, 3H-thymidine, L-11C- or 3H-methionine, gallium-67 citrate (67Ga-citrate) and iodine-125 human serum albumin (125I-HSA) was determined in these animals . 3H-FDG uptake in the infectious foci was evaluated by autoradiography of histological sections . Although 18F-FDG, 67Ga-citrate, and 125I-HSA showed comparatively high uptake in the infected muscle {the percentage activity of injected dose (ID) per gram of tissue normalized for rat weight in kilogram (%ID/g)xkg at 2 h postinjection was as follows: 18F-FDG, 0.184+/-0.026 to 0.218+/-0.046; 67Ga-citrate, 0.221+/-0.016; 125I-HSA, 0 . 198+/-0.019}, the infected muscle to blood ratio was much higher for 18F-FDG than for 67Ga-citrate or 125I-HSA (18F-FDG, 10.31+/-0.76 to 14.89+/-2.26; 67Ga-citrate, 1.24+/-0.67; 125I-HSA, 0.20+/-0.02) . The draining reactive lymph nodes also showed higher accumulation of 18F-FDG than of 67Ga-citrate or 125I-HSA . The uptake of 3H-thymidine and L-11C- or 3H-methionine in the infected muscle was lower than that of 18F- or 3H-FDG (at 2 h postinjection, 3H-thymidine = 0 . 039+/-0.005 and L-3H-methionine = 0.063+/-0.007 (%ID/g)xkg . Autoradiographs showed that the highest 3H-FDG uptake was seen in the area of inflammatory cell infiltration surrounding the necrotic region . In conclusion, 18F-FDG, which rapidly accumulates in sites of bacterial infection and in reactive lymph nodes with a high target to background ratio, appears to be a promising infection detection agent.

Biochem Biophys Res Commun, 1999 Apr 13, 257(2), 635 - 41
Interferon-gamma, bacterial lipopolysaccharide, and tumor necrosis factor-alpha induce CD11a mRNA and protein via Na+/H+ exchange and protein kinase C-dependent mechanisms in tissue macrophages; Shackelford RE; Previously CD11a or leukocyte function-associated antigen alpha-1 was found to be induced at the surface protein level in thioglycolate-elicited peritoneal macrophages by bacterial lipopolysaccharide and interferon-gamma . To investigate this induction further, Northern blotting and enzyme-linked immunosorbent assays were used to examine the role of second messengers in CD11a gene product induction by these agents . Here I report that CD11a RNA and cell surface protein induced by bacterial lipopolysaccharide and tumor necrosis factor-alpha are sensitive to inhibition of protein kinase C, while insensitive to inhibition of Na+/H+ exchange . CD11a induction by interferon-gamma conversely is sensitive to inhibition of Na+/H+ exchange and insensitive to inhibition of protein kinase C . These observations indicate that CD11a may be induced by multiple and separate second messenger systems in primary macrophages .

J Neuropathol Exp Neurol, 1999 Mar, 58(3), 265 - 74
Apoptosis of neurons in the dentate gyrus in humans suffering from bacterial meningitis; Nau R et al.; Apoptosis of granular cells in the dentate gyrus frequently occurs in animal models of bacterial meningitis . In 37 autopsy cases of bacterial meningitis we evaluated, by light microscopy and in-situ tailing, whether this pattern of neuronal damage is of relevance in humans . Neuronal apoptoses in the dentate gyrus (density 1 to 19/mm2) were observed in 26 cases of bacterial meningitis and in none of 10 aged-matched control cases dying from non-neurological diseases . The density of apoptotic neurons depended on the interval between the onset of symptoms of meningitis and death (death within the first 2 days: 1.8+/-2.8 apoptoses/mm2; later than 18 days: 1.8+/-1.7/mm2; compared to death between days 3 and 18: 7.4+/-6.6 apoptoses/mm2, p = 0.007 and 0.004, respectively) . Neuronal apoptosis in the dentate gyrus was not linked to neuronal damage in other parts of the brain or previous treatment with corticosteroids . Since learning deficits are frequently observed in survivors of bacterial meningitis, strategies to reduce the density of apoptotic neurons in the dentate gyrus may decrease the frequency of neurological sequela in patients surviving bacterial meningitis.

Cancer Res, 1999 Apr 1, 59(7), 1417 - 21
Superiority of yeast over bacterial cytosine deaminase for enzyme/prodrug gene therapy in colon cancer xenografts; Kievit E et al.; The enzyme/prodrug strategy using bacterial cytosine deaminase (bCD) and 5-fluorocytosine (5-FC) is currently under investigation for cancer gene therapy . A major limitation for the use of bCD is that it is inefficient in the conversion of 5-FC into 5-fluorouracil . In the present study, we show that the K(m) of yeast cytosine deaminase (yCD) for 5-FC was 22-fold lower when compared with that of bCD . HT29 human colon cancer cells transduced with yCD (HT29/yCD) were significantly more sensitive to 5-FC in vitro than HT29 cells transduced with bCD (HT29/bCD) . In tumor-bearing nude mice, complete tumor regression was observed in 6 of 13 HT29/yCD tumors in response to 5-FC treatment (500 mg/kg i.p . daily, 5 days a week for 2 weeks), whereas 0 of 10 HT29/bCD tumors were cured . Our study demonstrates an improved efficacy of the CD/5-FC treatment strategy when yCD was used . This enzyme has, therefore, a high potential to increase the therapeutic outcome of the enzyme/prodrug strategy in cancer patients.

Thorax, 1998 Dec, 53(12), 1047 - 52
Inflammatory response after inhalation of bacterial endotoxin assessed by the induced sputum technique; Thorn J et al.; BACKGROUND: Organic dusts may cause inflammation in the airways . This study was performed to assess the usefulness of the induced sputum technique for evaluating the presence of airways inflammation using inhaled endotoxin (lipopolysaccharide) as the inducer of inflammation . METHODS: To characterise the inflammatory response after inhalation of endotoxin, 21 healthy subjects inhaled 40 micrograms lipopolysaccharide and were examined before and 24 hours after exposure . Examinations consisted of a questionnaire for symptoms, spirometric testing, blood sampling, and collection of induced sputum using hypertonic saline . Eleven of the subjects inhaled hypertonic saline without endotoxin exposure as controls . Cell counts, eosinophilic cationic protein (ECP), and myeloperoxidase (MPO) were determined in blood and sputum . RESULTS: A significantly higher proportion of subjects reported respiratory and general symptoms after endotoxin inhalation . MPO and the number of neutrophils in the blood were higher and spirometric values were decreased after the lipopolysaccharide challenge . In the sputum MPO, ECP, and the numbers of neutrophils and lymphocytes were higher after the lipopolysaccharide challenge . No significant differences were found after the inhalation of hypertonic saline compared with before, except for a significantly lower number of lymphocytes in the sputum . CONCLUSIONS: The results support previous studies that inhaled endotoxin causes an inflammation at the exposure site itself, as well as general effects . Sampling of sputum seems to be a useful tool for assessing the presence of airways inflammation, and the inhalation of hypertonic saline used to induce sputum did not significantly interfere with the results found after inhalation of lipopolysaccharide.

J Appl Physiol, 1999 Apr, 86(4), 1311 - 8
Gas supersaturation in the cecal wall of mice due to bacterial CO2 production; Rasmussen H et al.; PCO2 in the lumen and serosa of cecum and jejunum was measured in mice . The anesthetic used was a fentanyl-fluanisone-midazolam mixture . PCO2 was recorded in vivo and postmortem . PCO2 was 409 +/- 32 Torr (55 +/- 4 kPa) in the cecal lumen and 199 +/- 22 Torr (27 +/- 3 kPa) on the serosa in normal mice . Irrigation of the cecum resulted in serosal and luminal PCO2 levels of 65-75 Torr . Cecal PCO2 was significantly lower in germ-free mice (65 +/- 5 Torr) . Cecal PCO2 increased significantly after introduction of normal bacterial flora into germ-free mice . Introduction of bacterial monocultures into germ-free mice had no effect . After the deaths of the mice, cecal PCO2 increased rapidly in normal mice . The intestinal bacteria produced the majority of the cecal PCO2, and the use of tonometry in intestinal segments with a high bacterial activity should be interpreted with caution . We propose that serosal PCO2 levels >150-190 Torr (20-25 kPa) in the cecum of mice with a normal circulation may represent a state of gas supersaturation in the cecal wall.

Clin Infect Dis, 1999 Mar, 28(3), 505 - 13
Induction of prostaglandin release from macrophages by bacterial endotoxin; Offenbacher S et al.; This review summarizes the role of the monocytic responses to lipopolysaccharide as it relates to periodontal disease severity . Data are presented which illustrate that the levels of prostaglandin E2 (PGE2) secreted by systemic peripheral blood monocytes in culture, in the presence of bacterial endotoxins, are highly correlated with the levels observed in the gingival crevicular fluid . Furthermore, the different periodontal diagnostic categories have varying levels of monocytic and crevicular fluid PGE2, in juxtaposition with clinical disease severity . These data are consistent with the concept that there is close synchrony between the systemic responsiveness of peripheral blood monocytes with regard to prostanoid synthesis and the local levels of mediator present within the gingival crevice.

J Trop Pediatr, 1999 Feb, 45(1), 48 - 51
Signs of severe bacterial infection in neonates; Ronfani L et al.; The objective of this study was to identify a short list of valid signs for the development of standard case management guidelines for severe bacterial infection (SBI) in newborn infants, an important cause of neonatal deaths in low-income countries . The reported and observed signs of 83 sick neonates admitted during 12 consecutive months were recorded . At discharge, 50 cases were classified, using predefined criteria, as SBI, mostly pneumonia, and 33 as other disease . The neonates with other diseases were significantly younger than those with SBI . None of the reported and observed signs, when used alone, had a high sensitivity, an important feature for a severe disease amenable to effective treatment . The best sensitivity (74 per cent) was obtained when a doctor observed severe chest indrawing or fast breathing or 'not looking well'; the specificity was 67 per cent and the positive predictive value 77 per cent . The sensitivity of reported difficult breathing and of observed severe chest indrawing, when measured only for the diagnosis of pneumonia, improved to 77 per cent, with a specificity of 84 per cent and 66 per cent, respectively . Reported fever and the observation that the neonate was 'not looking well' were the best independent predictors of SBI on logistic regression analysis . Simple standard case management (SCM) guidelines based only on reported and observed clinical signs would not identify the majority of neonates with SBI at primary health care level.

Genomics, 1999 Apr 1, 57(1), 62 - 9
A 1-Mb bacterial clone contig spanning the endometrial cancer deletion region at 1p32-p33; Arlt MF et al.; Our laboratory previously reported a high frequency of loss of heterozygosity (LOH) at 1p32-p33 in endometrial cancers . LOH at 1p32-p33 is a specific feature of one of the most aggressive forms of endometrial carcinoma, uterine papillary serous cancer (UPSC) . The minimum region of allelic loss in UPSC is defined by D1S190 and D1S447, an interval corresponding to less than 1 cM . Here we describe the construction and characterization of a sequence-ready clone contig that spans the deletion region . The contig consists of 24 bacterial artificial chromosome clones and 18 P1 artificial chromosome clones and spans approximately 1050 kb . The consensus region of allelic loss between D1S190 and D1S447 represents approximately 792 kb . Eight previously described ESTs have been positioned within the contig .

Appl Environ Microbiol, 1999 Apr, 65(4), 1721 - 30
Molecular analysis of bacterial community structure and diversity in unimproved and improved upland grass pastures; McCaig AE et al.; Bacterial community structure and diversity in rhizospheres in two types of grassland, distinguished by both plant species and fertilization regimen, were assessed by performing a 16S ribosomal DNA (rDNA) sequence analysis of DNAs extracted from triplicate soil plots . PCR products were cloned, and 45 to 48 clones from each of the six libraries were partially sequenced . Phylogenetic analysis of the resultant 275 clone sequences indicated that there was considerable variation in abundance in replicate unfertilized, unimproved soil samples and fertilized, improved soil samples but that there were no significant differences in the abundance of any phylogenetic group . Several clone sequences were identical in the 16S rDNA region analyzed, and the clones comprised eight pairs of duplicate clones and two sets of triplicate clones . Many clones were found to be most closely related to environmental clones obtained in other studies, although three clones were found to be identical to culturable species in databases . The clones were clustered into operational taxonomic units at a level of sequence similarity of >97% in order to quantify diversity . In all, 34 clusters containing two or more sequences were identified, and the largest group contained nine clones . A number of diversity, dominance, and evenness indices were calculated, and they all indicated that diversity was high, reflecting the low coverage of rDNA libraries achieved . Differences in diversity between sample types were not observed . Collector's curves, however, indicated that there were differences in the underlying community structures; in particular, there was reduced diversity of organisms of the alpha subdivision of the class Proteobacteria (alpha-proteobacteria) in improved soils.

J Gen Physiol, 1999 Apr, 113(4), 525 - 40
Energetic and spatial parameters for gating of the bacterial large conductance mechanosensitive channel, MscL; Sukharev SI et al.; MscL is multimeric protein that forms a large conductance mechanosensitive channel in the inner membrane of Escherichia coli . Since MscL is gated by tension transmitted through the lipid bilayer, we have been able to measure its gating parameters as a function of absolute tension . Using purified MscL reconstituted in liposomes, we recorded single channel currents and varied the pressure gradient (P) to vary the tension (T) . The tension was calculated from P and the radius of curvature was obtained using video microscopy of the patch . The probability of being open (Po) has a steep sigmoidal dependence on T, with a midpoint (T1/2) of 11.8 dyn/cm . The maximal slope sensitivity of Po/Pc was 0.63 dyn/cm per e-fold . Assuming a Boltzmann distribution, the energy difference between the closed and fully open states in the unstressed membrane was DeltaE = 18.6 kBT . If the mechanosensitivity arises from tension acting on a change of in-plane area (DeltaA), the free energy, TDeltaA, would correspond to DeltaA = 6.5 nm2 . MscL is not a binary channel, but has four conducting states and a closed state . Most transition rates are independent of tension, but the rate-limiting step to opening is the transition between the closed state and the lowest conductance substate . This transition thus involves the greatest DeltaA . When summed over all transitions, the in-plane area change from closed to fully open was 6 nm2, agreeing with the value obtained in the two-state analysis . Assuming a cylindrical channel, the dimensions of the (fully open) pore were comparable to DeltaA . Thus, the tension dependence of channel gating is primarily one of increasing the external channel area to accommodate the pore of the smallest conducting state . The higher conducting states appear to involve conformational changes internal to the channel that don't involve changes in area.

Immunopharmacology, 1999 Feb, 41(2), 165 - 8
Monophosphoryl lipid A, a derivative of bacterial lipopolysaccharide, fails to induce B1-receptor-dependent responses to (des-Arg9)-bradykinin in the rabbit in vivo; Mazenot C et al.; OBJECTIVE: The aim of this study was to evaluate whether monophosphoryl lipid A (MLA) was able to induce a hypotensive response to (des-Arg9)-bradykinin in the rabbit in vivo, by inducing B1-receptor synthesis . MATERIALS AND METHODS: Arterial pressure was measured after intra-arterial administration of B1- and B2-receptor agonists and antagonists in control rabbits and in rabbits pre-treated 24 h earlier with MLA (100 microg kg(-1) i.v.) or lipopolysaccharide (LPS) (10 microg kg(-1) i.v.) . RESULTS: Intra-arterial bradykinin administration induced a similar dose-dependent hypotension in all groups (BK 0.25 microg kg(-1), 36 +/- 3 mm Hg, BK 1 microg kg(-1), -39 +/- 3 mm Hg, p < 0.05 vs . control conditions) that was significantly antagonised by intra-arterial HOE 140 (2 microg kg(-1)) (-5 +/- 2 mm Hg, p < 0.05) . Intra-arterial (des-Arg9)-bradykinin induced a hypotensive response in the LPS-pre-treated group (DBK 1 microg kg(-1), -6 +/- 1 mm Hg, DBK 10 microg kg(-1), -10 +/- 1 mm Hg, p < 0.05 vs . control conditions) that was totally abolished by intra-arterial (des-Arg9, Leu8)-bradykinin (10 microg kg(-1) min(-1)) (+1 +/- 2 mm Hg, p < 0.05) . In the control and MLA-pre-treated groups, (des-Arg9)-bradykinin had no effect . CONCLUSION: MLA pre-treatment did not induce a hypotensive response to (des-Arg9)-bradykinin . We conclude that, in contrast to LPS, MLA does not induce B1-receptor synthesis, 24 h after its administration in the rabbit . Thus, the cardioprotective effects of MLA do not appear to be related to the kinin pathway.

Neurology, 1999 Mar 23, 52(5), 1003 - 9
Bacterial meningitis in adults: demonstration of inner ear involvement using high-resolution MRI; Dichgans M et al.; OBJECTIVE: To visualize the sites involved in audiovestibular dysfunction during bacterial meningitis in adults and to relate these findings to the extent of hearing impairment and vestibular dysfunction . BACKGROUND: Hearing impairment is among the most frequent complications of bacterial meningitis . METHODS: High-resolution MRI (HR-MRI) of the inner ear was performed in seven adult patients with hearing loss as a complication of bacterial meningitis . Results: Five patients had unilateral (n = 1) or bilateral (n = 4) contrast enhancement of vestibulocochlear structures . The structures most frequently involved were the cochlear nerve (n = 9), the first cochlear turn (n = 9), the vestibulum (n = 9), and the semicircular canals (n = 7) . There was a significant correlation between clinical and MRI findings: all nine ears with cochlear enhancement were deaf (hearing loss >90 dB), whereas none of the five ears with normal MRI findings had hearing losses of more than 90 dB (range, 30 to 70 dB; p = 0.0005) . Vestibular dysfunction as revealed clinically and by quantitative vestibular function testing was found in six of seven patients (11 of 14 ears) . Five of these patients (nine ears) also demonstrated enhancement of the vestibular organ on high-resolution MRI of the inner ear . CONCLUSIONS: High-resolution MRI can visualize the involvement of vestibulocochlear structures in bacterial meningitis in both cooperative and consciously impaired patients . These findings suggest a correlation between abnormalities on MRI and the extent of cochlear dysfunction.

Sex Transm Dis, 1999 Mar, 26(3), 137 - 42
Comparison of once-daily and twice-daily dosing of 0.75% metronidazole gel in the treatment of bacterial vaginosis; Livengood CH 3rd et al.; BACKGROUND AND OBJECTIVES: Bacterial vaginosis is the most common cause of vaginal symptoms in women and has potential complications . Efforts to improve treatment of this disease process are warranted . GOAL OF THIS STUDY: The goal of this study was to compare the safety and efficacy of once-daily intravaginal administration of 0.75% metronidazole gel for 5 days to the established twice-daily regimen in the treatment of bacterial vaginosis . STUDY DESIGN: Nonpregnant women with bacterial vaginosis diagnosed by accepted clinical criteria at 14 geographically diverse general gynecology clinics were enrolled in this prospective, randomized, investigator-blind, parallel study . They were treated with either once-daily or twice-daily 0.75% metronidazole gel 5 g intravaginally for 5 days and were reevaluated at 7 to 12 days and 28 to 35 days after completing treatment . Efficacy was determined by clinical criteria . Adverse drug reactions were monitored . RESULTS: Of the 514 evaluable women enrolled, bacterial vaginosis was cured at the first return visit among evaluable patients in 153 of 199 (77%) of those who received the once-daily and in 157 of 196 (80%) of those who received the twice-daily administration . Bacterial vaginosis was cured among evaluable patients at the final visit in 104 of 180 (58%) of those who received once-daily and 109 of 178 (61%) of those who received the twice-daily regimen . Intent-to-treat analysis showed cure at 1 month in 118 of 207 (57%) of those treated once daily and 129 of 209 (62%) of those treated twice daily . Side effects were mild, and none caused treatment discontinuation . CONCLUSIONS: Once-daily dosing of 0.75% metronidazole gel 5 g for 5 days yields efficacy, safety, and tolerance equivalent to the currently used twice-daily dosing in the treatment of bacterial vaginosis, adding another competitive choice to the available therapeutic options for this condition.

Trends Genet, 1999 Feb, 15(2), 70 - 4
Upheaval in the bacterial nucleoid . An active chromosome segregation mechanism; Sharpe ME et al.; Recent advances have completely overturned the classical view of chromosome segregation in bacteria . Far from being a passive process involving gradual separation of the chromosomes, an active, possibly mitotic-like machinery is now known to exist . Soon after the initiation of DNA replication, the newly replicated copies of the oriC region, behaving rather like eukaryotic centromeres, move rapidly apart towards opposite poles of the cell . They then determine the positions that will be taken up by the newly formed sister nucleoids when DNA replication has been completed . Thus, the gradual expansion of the diffuse nucleoid camouflages an underlying active mechanism . Several genes involved in chromosome segregation in bacteria have now been defined; their possible functions are discussed.

J Acquir Immune Defic Syndr Hum Retrovirol, 1999 Apr 1, 20(4), 382 - 6
Bacterial vaginosis associated with HIV infection in pregnant women from North Carolina; Royce RA et al.; BACKGROUND: We investigated whether bacterial vaginosis is associated with HIV infection in pregnant women in North Carolina, U.S.A . METHODS: At 24 to 29 weeks' gestation, we recruited 724 women receiving prenatal care to provide interview information and vaginal swabs for Gram's stain scoring of vaginal flora . FINDINGS: As vaginal flora score increased, prevalence of HIV increased (trend p = .03) . HIV prevalence was 0.8% (4 of 489 patients), 1.2% (1 of 84 patients), and 3.3% (5 of 151 patients) among women with normal, intermediate, and abnormal vaginal flora, respectively . All HIV-infected women were free from AIDS and were taking antiretroviral medication . Compared with women with normal vaginal flora, the relative risk for prevalence of HIV infection with intermediate flora was 1.5 (95% confidence interval {CI}, 0.2, 12.9) and with abnormal flora was 4.0 (95% CI, 1.1, 14.9) . The association between abnormal vaginal flora and HIV infection could not be explained by age, ethnicity, number of sexual partners in the past 6 months, sexually transmitted diseases (STDs), or douching during pregnancy . INTERPRETATION: In a population with a relatively low HIV prevalence, vaginal flora abnormalities were associated with prevalent HIV infection . We cannot determine whether vaginal flora abnormalities increase women's susceptibility to HIV infection or become more common after infection . The increased prevalence of bacterial vaginosis among HIV-infected pregnant women increases risk for preterm delivery . Incidence studies are required to discern whether control of bacterial vaginosis might reduce HIV infectivity.

J Heart Valve Dis, 1999 Jan, 8(1), 71 - 3
Mitral valve homograft for mitral valve replacement in acute bacterial endocarditis; Reardon MJ et al.; Homograft use for aortic valve replacement (AVR) in aortic valve acute bacterial endocarditis (ABE) has gained in popularity, due mainly to the relative resistance of homografts to infection . Recent success with mitral valve homograft use led us to apply homograft mitral valve replacement (MVR) in a patient with severe ABE that was not amenable to valve repair . Following surgery, the patient improved rapidly with normalization of infection parameters and chest radiography, and was discharged home on postoperative day 11 . Follow up echocardiography showed good function of the homograft mitral valve with no regurgitation . After four months, the patient had normal valve function, with no evidence of infection . In conclusion, MVR with a mitral valve homograft in the setting of ABE was satisfactory, though patient follow up was relatively short (four months).

Eur J Biochem, 1999 Mar, 260(2), 414 - 20
Drosophila melanogaster transferrin . Cloning, deduced protein sequence, expression during the life cycle, gene localization and up-regulation on bacterial infection; Yoshiga T et al.; Drosophila melanogaster transferrin cDNA was cloned from an ovarian cDNA library by using a PCR fragment amplified by two primers designed from other dipteran transferrin sequences . The clone (2035 bp) encodes a protein of 641 amino acids containing a signal peptide of 29 amino acids . Like other insect transferrins, Drosophila transferrin appears to have a functional iron-binding site only in the N-terminal lobe . The C-terminal lobe lacks iron-binding residues found in other transferrins, and has large deletions which make it much smaller than functional C-terminal lobes in other transferrins . In-situ hybridization using a digoxigenin labeled transferrin cDNA probe revealed that the gene is located at position 17B1-2 on the X chromosome . Northern blot analysis showed that transferrin mRNA was present in the larval, pupal and adult stages, but was not detectable in the embryo . Iron supplementation of the diet resulted in lower levels of transferrin mRNA . When adult flies were inoculated with bacteria (Escherichia coli), transferrin mRNA synthesis was markedly increased relative to controls.

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