Hepatology, 1999 Apr, 29(4), 1057 - 63 Vascular endothelial growth factor production in peritoneal macrophages of cirrhotic patients: regulation by cytokines and bacterial lipopolysaccharide; Perez-Ruiz M et al.; Vascular endothelial growth factor (VEGF) is an angiogenic peptide with vascular permeability and relaxing properties . This study assessed whether peritoneal macrophages of cirrhotic patients can be up-regulated to produce VEGF under proper stimulatory conditions . Macrophages were isolated from ascites . VEGF protein secretion and mRNA expression were measured in basal conditions and after stimulation with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), and interleukin-1 (IL-1) . These substances induced a time- and dose-dependent increase in both VEGF production and transcript expression . Assays with actinomycin D showed that VEGF mRNA induction is secondary to both higher VEGF gene transcription and mRNA stability . Ascites and plasma concentration of VEGF was also measured in cirrhotic patients with (n = 15) and without (n = 10) spontaneous bacterial peritonitis (SBP) . Plasma values did not differ between both groups of patients . However, ascites VEGF levels were higher in SBP patients than in noninfected cirrhotic patients (710 +/- 183 vs . 94 +/- 15 pg/mL; P <.025) . These results indicate that cytokines and LPS markedly increase VEGF protein secretion and mRNA expression in macrophages of cirrhotic patients, and suggest that this substance could be an important mediator of the pronounced arterial vasodilation frequently occurring in SBP patients. FEBS Lett, 1999 Feb 26, 445(2-3), 384 - 8 Key role of barstar Cys-40 residue in the mechanism of heat denaturation of bacterial ribonuclease complexes with barstar; Protasevich II et al.; The mechanism by which barnase and binase are stabilized in their complexes with barstar and the role of the Cys-40 residue of barstar in that stabilization have been investigated by scanning microcalorimetry . Melting of ribonuclease complexes with barstar and its Cys-82-Ala mutant is described by two 2-state transitions . The lower-temperature one corresponds to barstar denaturation and the higher-temperature transition to ribonuclease melting . The barstar mutation Cys-40-Ala, which is within the principal barnase-binding region of barstar, simplifies the melting to a single 2-state transition . The presence of residue Cys-40 in barstar results in additional stabilization of ribonuclease in the complex. Pathol Res Pract, 1999, 195(2), 89 - 92 The role of persisting infections in the pathogenesis of pulmonary emphysema . Electron microscopy reveals a probable bacterial colonization of the alveolar space and the bronchioles; Theegarten D et al.; Lung volume reduction surgery (LVRS) yields resection specimens from patients with advanced pulmonary emphysema . Regarding the development of lung function parameters, recent results obtained by light microscopy revealed an unfavorable prognosis in patients with remarkable inflammation, particularly in the bronchioli . Tissue from ten patients (alpha1-antitrypsin level in the normal range) was furthermore investigated by electron microscopy . Scanning electron microscopy shows 0.4-0.6 micron spherical bodies variably densely arranged in the whole alveolar space and in the bronchioles of all patients . These bodies are mostly seen on the microvilli of type II pneumocytes . An immunological reaction with activation of macrophages and granulocytes occurs simultaneously . Macrophages show cytoplasmic extensions to the spherical bodies, which exhibit a cellular membrane but no cellular wall . This favors the diagnosis of bacterial colonization of the alveolar space and the bronchioles by mycoplasmas or L-forms of other bacteria . As patients undergoing lung volume reduction surgery are under optimal medical treatment and without any infection clinically, these findings appear to be relevant for the pathogenesis and/or progression of pulmonary emphysema. Pediatr Pulmonol Suppl, 1999, 18, 141 - 3 The role of viral and atypical bacterial pathogens in asthma pathogenesis; Johnston SL; The recent development of PCR for the diagnosis of respiratory viral infections has permitted studies revealing the importance of virus infections in acute exacerbations of asthma . Several studies implicate rhinovirus as the major virus type in mild and severe wheezing illness in children of all age groups, but particularly over 1 year of age . Rhinoviruses have been shown to replicate in the lower airway, suggesting that virus induced asthma exacerbations result from direct inoculation, spread of the virus from the upper to the lower airway . The importance of RS virus infection in bronchiolitis and wheezing in infants has been reaffirmed . Recent studies using PCR to detect C pneumoniae, suggests a high prevalence of chronic infection in asthmatic children, and that the immune response to this organism may play a pathological role in asthma . These studies now require confirmation with larger carefully controlled studies. Biochem Mol Biol Int, 1999 Jan, 47(1), 117 - 25 The polarization model in bacterial photosynthesis; Borisov AYu et al.; The widely accepted model of reaction center /RC/ functioning is proved to come into contradiction with some recent data . In particular, it cannot explain why only a minor part of electronic excitations (approximately 10%) escapes from excited RC special pairs back to antenna BChls . Therefore we believe that the model must be substantially modernized . In 1981 we developed a new model/1,2/ . We suggested a femtosecond state to precede primary e-transfer reaction due to reorientation of water molecule dipole in the electric field of excited RC dimer . This mechanism is responsible for energy trapping before the primary e-transport occurs . During last years his mechanism got support from various experimental works . Now this polarization model claims to fit all reliable experimental data at least in bacterial photosynthesis. Acta Crystallogr D Biol Crystallogr, 1999 Feb, 55 ( Pt 2), 549 - 51 Crystallization of L-aspartate oxidase, the first enzyme in the bacterial de novo biosynthesis of NAD; Bacchella L et al.; The flavoenzyme L-aspartate oxidase from Escherichia coli was crystallized using the hanging-drop vapour-diffusion technique with PEG 4000 as precipitant . The crystals belong to space group P3121 (or P3221) with unit-cell parameters a = b = 84.9, c = 159.9 A . A solvent content of 42% corresponds to a monomer (60 kDa) in the asymmetric unit . A complete 2.8 A resolution data set was collected using a rotating-anode X-ray generator. Acta Crystallogr D Biol Crystallogr, 1999 Apr, 55 ( Pt 4), 915 - 7 Crystallization and preliminary x-ray diffraction studies of a novel bacterial esterase; Bourne PC et al.; A novel bacterial esterase has been crystallized in two forms suitable for X-ray diffraction studies . Crystals have been obtained by vapour-phase diffusion at 290 K using ammonium sulfate as precipitant . The first crystals grew in space group C2 with unit-cell parameters a = 134.7, b = 55.8, c = 110.3 A, beta = 125.1 degrees . A monoclinic data set has been collected to 2.0 A resolution . Microseeding yielded a second crystal form which grew in space group P212121 with unit-cell parameters a = 57.1, b = 115.4, c = 130.4 A . Native data from these crystals have been collected to 1.6 A resolution . A molecular envelope has been determined using an uranyl acetate derivative for phase calculation. Lab Anim Sci, 1999 Feb, 49(1), 62 - 9 Bacterial lipopolysaccharide induces a conduction block in the sciatic nerves of rats; Brown RF et al.; A single injection of Escherichia coli lipopolysaccharide (LPS; intraperitoneally {i.p.} and intravenously {i.v.}) reliably induces peripheral nerve disturbances in the hindlimbs of inbred Australian albino Wistar (AaW) rats . In the series of experiments presented here, we aimed to characterize this syndrome by examining electrophysiologic, immunologic, and immunochemical features . The LPS-induced neurologic sequelae in AaW rats were transient, at least partly reversible by drug treatment, and were not associated with any detectable neuropathologic findings by light microscopy . Neurologic sequelae were prevented by administration of dexamethasone and by pretreatment with the macrophage inhibitor gadolinium chloride, suggesting that they were caused by LPS-induced activation of peripheral macrophages . Sequelae were associated with early decreases in compound muscle-action potential amplitudes, indicating impaired functioning of either proximal sciatic nerve axons and/or neuromuscular synapses . Spinal somatosensory-evoked potential latencies also were increased, indicating impaired somatosensory function at the sciatic nerve, dorsal roots, spinal cord, and/or postsynaptic interneurons, although the precise location of impairment could not be delineated . Similarities between this syndrome and immune-mediated polyneuropathies in humans are discussed. Fogorv Sz, 1999 Feb, 92(2), 45 - 50 {Bacterial flora of odontogenic and non-odontogenic inflammations of the oro-facial region}; Szontagh E et al.; Samples were collected from 34 patients after extraoral incision in case of infections of oro-facial region (29 odontogen and 5 non odontogen) . The authors examined the prevalence, ration and susceptibility of the isolated bacteria to antibiotics . The 98-100% of the bacteria has found were sensitive to Clindamycin and Amoxicillin/Clavulan acid . These antibiotics could be the first choice to treat the above mentioned diseases. Arch Surg, 1999 Mar, 134(3), 287 - 92 Enteral nutrition prevents bacterial translocation but does not improve survival during acute pancreatitis; Kotani J et al.; OBJECTIVE: To evaluate the effect of enteral nutrition (EN) in attenuating bacterial and/or endotoxin translocation, maintaining immune responsiveness, and improving outcome in early acute pancreatitis (AP) in Wistar male rats . DESIGN: Acute pancreatitis was induced in rats receiving total parenteral nutrition (TPN) (AP/TPN group) (n=34) and EN (AP/EN group) (n=35) by pressure injection of 1% deoxycholate into the biliopancreatic duct (0.6 mg/kg of body weight) . Rats in the sham/TPN and sham/EN groups (n=10 each) underwent laparotomy without induction of AP . Catheters for TPN and EN were placed into the external jugular vein and jejunum, respectively . Rats were infused with Ringer lactate solution for 48 hours followed by TPN in the AP/TPN and sham/TPN groups, and EN in the AP/EN and sham/EN groups until day 7 . The fluid volume and energy (calories) intake were similar in all groups . SETTING: Medical school research laboratory . MAIN OUTCOME MEASURES: Survival, blood endotoxin level, villus height, 5-bromo-2'-deoxyuridine (BrdU) uptake in the jejunum and ileum, bacterial culture of mesenteric lymph nodes, and CD4/CD8 ratio of T cells in mesenteric lymph nodes, spleen, and peripheral blood . RESULTS: There was no difference in survival and pancreatic healing between the AP/TPN and AP/EN groups . Colony-forming units of the mesenteric lymph nodes and the endotoxin level were significantly lower in the AP/EN group than in the AP/TPN group (P<.05) . Villus height and BrdU intake was significantly higher in the AP/EN group than in the AP/TPN group (P<.05) . The CD4/CD8 ratio of T cells in spleen and peripheral blood was higher in the AP/EN group than in the AP/TPN group (P<.05), whereas there was no difference in mesenteric lymph nodes . CONCLUSIONS: Jejunal administration of EN is well tolerated in early AP, maintains immune responsiveness and gut integrity, and reduces bacterial and/or endotoxin translocation . However, compared with TPN, EN does not improve outcome . These results suggest that factors other than bacterial and/or endotoxin translocation may be responsible for mortality in this rat model of early AP . However, additional studies of both early bacterial and/or endotoxin translocation and late assessment of outcome are indicated. Scand J Clin Lab Invest, 1998 Dec, 58(8), 661 - 8 A modified fast micro method in agarose for isotype, allotype, light chain and idiotype-specific analysis of antibody clonotypes to bacterial virulence antigens; Nagao AT et al.; A modified fast micro method for spectrotypic/clonotypic analysis of human IgG1-4 antibodies against bacterial virulence antigens of polysaccharide or protein nature is described . Serum samples of as small volumes as 0.5 microliter were isoelectrically focused in micro agarose gels made in plexiglass matrices and blotted using immunoaffinity-mediated capillary blotting onto nitrocellulose membranes previously coated with antigen . The bands of the antigen-specific antibodies were identified with respect to isotypes, light chain types, allotypes or idiotypes by incubating the nitrocellulose membranes with mouse monoclonal anti-human IgG subclass antisera and then with alkaline phosphatase-conjugated rabbit anti-mouse immunoglobulins . The method was applied for characterization of human monoclonals against tetanus toxoid (TT) and for the analysis of variable patterns of clonotypes in IgG subclass-deficient patients . The usefulness of the technique was also demonstrated by comparing the variable specificity and reactivity of different commercial monoclonals against human IgG subclasses . This method is fast, specific, sensitive, uses little material, is simple and reproducible. Ann Hum Genet, 1998 Sep, 62 ( Pt 5), 401 - 9 Construction of a bacterial artificial chromosome (BAC) contig across the minimally deleted region in 13q14.3 in B-cell chronic lymphocytic leukemia; Hawthorn LA et al.; Loss of heterozygosity (LOH) analysis in B-cell chronic lymphocytic leukemia (BCLL) has indicated that a frequent genetic event is loss of alleles from an approximately 500 kb region in 13q14.3, distal to the retinoblastoma gene . We have used DNA markers from this region to isolate and characterize a series of bacterial artificial chromosomes (BACs) which span the region between markers D13S319 and D13S25, which represents the common region of LOH . This entire region appears to be contained within only two minimally overlapping BACs, representing a maximum distance of approximately 350 kb . This BAC contig has been used to position known STS, EST and gene markers within the region . We have also used a modified differential display/RNA fingerprinting procedure designed to isolated transcribed sequences from YACs to isolate two transcribed units from the region which have also been positioned within the contig . The construction of a BAC contig with minimal redundancy provides the ideal resources from which to begin to identify candidate genes related to BCLL. Nihon Kokyuki Gakkai Zasshi, 1999 Jan, 37(1), 10 - 3 {Influence of beclomethasone dipropionate inhalation therapy on respiratory bacterial infection in patients with an acute exacerbation of COPD}; Watanabe Y et al.; The aim of this clinical study was to investigate the influence of beclomethasone dipropionate (BDP) inhalation therapy on respiratory bacterial infections in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) . We studied 30 patients who had been admitted twice, (before and after the beginning BDP inhalation therapy) to our hospital because of an exacerbation of COPD by respiratory tract infection . No differences were observed before and after BDP inhalation therapy in values for PaO2, PaCO2, body temperature, CRP, WBC count, number of admission days, and bacterial culture of sputum on admission . These results suggest that BDP inhalation therapy has little influence on respiratory bacterial infection during exacerbation of COPD. Curr Top Microbiol Immunol, 1999, 241, 155 - 80 Mechanisms of Helicobacter pylori infection: bacterial factors; McGee DJ et al.; Since the discovery of H . pylori in 1982 (MARSHALL 1983; WARREN 1983), research on the mechanisms of virulence of H . pylori has advanced substantially . It is now well established that urease and flagella are virulence factors of H . pylori . Although known for some time to be toxic to epithelial cells in vitro, VacA has only recently been established as a virulence factor . The cag pathogenicity island has also emerged as another virulence contender, although the specific genes involved in virulence are still being determined . Other possible virulence factors, not yet confirmed by gene disruptions, are hapA, katA, sodA, cagA, and iron-regulated genes . As of yet, no adhesins have been confirmed as being important for in vivo survival of H . pylori . With the sequence of the H . pylori genome in hand, it should be possible to more easily determine the role of specific genes in virulence . Genes of immediate interest are the OMPs, which may under go phase and antigenic variation and may represent adhesins . Additionally, virulence-related orthologs and vacA-related genes may provide some interesting findings . Once we define the genes that contribute to H . pylori virulence, we may be able to more easily develop novel therapeutic drugs or vaccines to treat and prevent H . pylori infection. Pacing Clin Electrophysiol, 1999 Feb, 22(2), 393 - 6 Predominant tricuspid stenosis secondary to bacterial endocarditis in a patient with permanent pacemaker and balloon dilatation of the stenosis; Nisanci Y et al.; In a 49-year-old woman with sick sinus syndrome and a permanent VVI pacemaker, severe tricuspid stenosis and its clinical consequences developed 4 years after the attack of endocarditis . Besides the quite unusual occurrence of lead related tricuspid stenosis, successful treatment with balloon dilatation is the unique feature of this case. Genomics, 1999 Mar 15, 56(3), 337 - 9 pPAC-ResQ: A yeast-bacterial shuttle vector for capturing inserts from P1 and PAC clones by recombinogenic targeted cloning; Bhargava J et al.; We have developed a method to capture inserts from P1 and P1 artificial chromosome (PAC) clones into a yeast-bacteria shuttle vector by using recombinogenic targeting . We have engineered a vector, pPAC-ResQ, a derivative of pClasper, which was previously used to capture inserts from yeast artificial chromosome clones . pPAC-ResQ contains DNA fragments flanking the inserts in P1 and PAC vectors as recombinogenic ends . When linearized pPAC-ResQ vector and P1 or PAC DNA are cotransformed into yeast, recombination between the two leads to the transfer of inserts into pPAC-ResQ . pPAC-ResQ clones thus obtained can be further modified in yeast for functional analysis and shuttled to Escherichia coli to produce large quantities of cloned DNA . This approach provides a rapid method to modify P1/PAC clones for functional analysis . Genomics, 1999 Mar 15, 56(3), 237 - 46 Contig assembly of bacterial artificial chromosome clones through multiplexed fluorescence-labeled fingerprinting; Ding Y et al.; A rapid multiplexed fingerprinting method has been developed for bacterial artificial chromosome (BAC) contig assembly . Defined subsets of BAC DNA fragments that result from digestion by three paired restriction endonucleases are labeled with unique fluorescent F-ddATP for each subset . Lists of the labeled fragment size are generated by an ABI 377 DNA sequencer and the GeneScan analysis software and then processed by an assembly program, FPC (Fingerprinted Contigs), to produce contig maps . Data obtained from the multiplexed labeling permit detection of smaller overlaps than is observed when data from a single double-digest are analyzed . The method has been tested on 98 BACs from chromosome 22 regions where large-scale sequencing is under way and also through simulation, using randomly generated BAC clones derived from existing DNA sequence data . In each case, contig assembly results demonstrated the advantages of multiplexed fingerprinting . Arch Biochem Biophys, 1999 Apr 1, 364(1), 42 - 52 Bacterial expression and characterization of the ligand-binding domain of the vitamin D receptor; Strugnell SA et al.; The ligand-binding domain of the rat vitamin D receptor (amino acids 115-423) was expressed as an amino-terminal His-tagged protein in a bacterial expression system and purified over Ni-nitrilotriacetic acid resin and a Mono S column . The purified protein bound its ligand, 1,25-dihydroxyvitamin D3, with high affinity, similar to that of the full-length protein . Saturation of the protein with ligand quenched 90% of the tryptophan fluorescence, consistent with the purified protein being uniformly able to bind ligand . Addition of ligand produced no change in the tryptophan fluorescence lifetime, suggesting static quenching as the mechanism of fluorescence decrease . The near-UV circular dichroism spectrum showed a large increase in signal following the addition of ligand, consistent with a change in the environment of aromatic amino acid side chains . The far-UV circular dichroism spectrum was consistent with a protein of high alpha-helical content . Sedimentation equilibrium experiments demonstrated that the protein formed higher-order complexes, and the distribution of the protein among these complexes was significantly shifted by addition of ligand . Nat Med, 1999 Mar, 5(3), 298 - 302 Neuroprotection by a caspase inhibitor in acute bacterial meningitis; Braun JS et al.; Half of the survivors of bacterial meningitis experience motor deficits, seizures, hearing loss or cognitive impairment, despite adequate bacterial killing by antibiotics . We demonstrate that the broad-spectrum caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl-ketone (z-VAD-fmk) prevented hippocampal neuronal cell death and white blood cell influx into the cerebrospinal fluid compartment in experimental pneumococcal meningitis . Hippocampal neuronal death was due to apoptosis derived from the inflammatory response in the cerebrospinal fluid . Apoptosis was induced in vitro in human neurons by inflamed cerebrospinal fluid and was blocked by z-VAD-fmk . As apoptosis drives neuronal loss in pneumococcal meningitis, caspase inhibitors might provide a new therapeutic option directed specifically at reducing brain damage. Ostomy Wound Manage, 1999 Jan, 45(1A Suppl), 109S - 118S; quiz 119S-120S Bacterial colonization/infection and the surgical management of pressure ulcers; Brown DL et al.; The purpose of this paper is to review the current recommendations and guidelines for the care and treatment of pressure ulcers with specific reference to the control of infection within these wounds and surgical management . After reviewing the literature published between May 1993 and April 1998, it is our contention that no significant changes in the clinical management of this problem are warranted . This may signal the need for further study in this area . Recommendations for the optimal care of clean and infected pressure ulcers are included. Biochem J, 1999 Apr 1, 339 ( Pt 1), 33 - 6 Position-independent and copy-number-related expression of a goat bacterial artificial chromosome alpha-lactalbumin gene in transgenic mice; Stinnakre MG et al.; A bacterial artificial chromosome goat insert comprising the alpha-lactalbumin-encoding transcription unit with approximately 150 and 10 kb of 5'- and 3'-flanking sequences, respectively, was micro-injected into mouse eggs . In six out of seven transgenic lines, the level of mammary tissue- and stage-specific expression was position-independent and copy-number-dependent . The exogenous alpha-lactalbumin yield, about 0.8 mg/ml of milk per copy, compared favourably with the alpha-lactalbumin content of mouse and goat milks, about 0.8 and >1 mg/ml, respectively . This suggests that the insert contains most if not all of the cis-acting elements involved in the full and specific expression of the goat alpha-lactalbumin gene and opens up opportunities to use this vector to target expression of foreign genes in the lactating mammary gland of transgenic animals . The transgene was silent in the seventh line for an unknown reason. Infect Immun, 1999 Apr, 67(4), 1539 - 46 Febrile-range temperature modifies early systemic tumor necrosis factor alpha expression in mice challenged with bacterial endotoxin; Jiang Q et al.; Fever improves survival in acute infections, but the effects of increased core temperature on host defenses are poorly understood . Tumor necrosis factor alpha (TNF-alpha) is an early activator of host defenses and a major endogenous pyrogen . TNF-alpha expression is essential for survival in bacterial infections but, if disregulated, can cause tissue injury . In this study, we show that passively increasing core temperature in mice from the basal (36.5 to 37.5 degrees C) to the febrile (39.5 to 40 degrees C) range modifies systemic TNF-alpha expression in response to bacterial endotoxin (lipopolysaccharide) . The early TNF-alpha secretion rate is enhanced, but the duration of maximal TNF-alpha production is shortened . We identified Kupffer cells as the predominant source of the excess TNF-alpha production in the warmer animals . The enhanced early TNF-alpha production observed at the higher temperature in vivo could not be demonstrated in isolated Kupffer cells or in precision-cut liver slices in vitro, indicating the participation of indirect pathways . Therefore, expression of the endogenous pyrogen TNF-alpha is regulated by increments in core temperature during fever, generating an enhanced early, self-limited TNF-alpha pulse. Chest, 1999 Mar, 115(3), 829 - 35 Bacterial endotoxin is an active component of cigarette smoke; Hasday JD et al.; BACKGROUND: Chronic bronchitis in cigarette smokers shares many clinical and histologic features with environmental lung diseases attributed to bacterial endotoxin (lipopolysaccharide {LPS}) inhalation . Experimental LPS inhalation mimics many of the acute effects of cigarette smoke in the lower airway . Therefore, we reasoned that LPS may be a biologically active component of cigarette smoke . DESIGN: The Limulus amebocyte lysate (LAL) assay was used to measure LPS in the tobacco and filter tip components of unsmoked 1R4F experimental cigarettes and commercially available "light" cigarettes, as well as in mainstream (MS) and sidestream (SS) smoke particles generated with an automated smoking machine and collected on ventilator mainflow filters . SETTING AND PARTICIPANTS: Blood LPS activity and plasma cytokine concentrations were measured in groups of healthy smokers and nonsmokers who reported to the walk-in clinic at the Baltimore VA Medical Center for unrelated complaints . MEASUREMENTS: Blood LPS levels were measured by LAL assay and plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), soluble TNF receptors I and II (sTNFR I and sTNFR II) were measured by enzyme-linked immunosorbent assay . RESULTS: Bioactive LPS was detected in both the tobacco portion (1R4F, 17.8+/-1.0 microg/cigarette; light, 26.8+/-7.3 microg/cigarette {mean+/-SE}) and filter tips (1R4F, 0.67+/-0.55 microg/cigarette; light, 0.70+/-0.39 microg/cigarette) of cigarettes . Bioactive LPS was also detected in both MS (1R4F, 120+/-64 ng/cigarette; light: 45.3+/-16 ng/cigarette) and SS smoke (1R4F, 18+/-1.5 ng/cigarette; light: 75+/-49 ng/cigarette) . Although systemic absorption of inhaled LPS may occur, we failed to detect any differences between nonsmokers and smokers in median blood LPS levels (median values, 66.75 and 72.1 pg/mL, respectively; p = 0.55) or plasma concentrations of TNF-alpha (0 vs 0 pg/mL, respectively; p = 0.71), sTNFR I(1,469 vs 1,576 pg/mL, respectively), sTNFR II (2,011 vs 3,110 pg/mL, respectively), or IL-6 (8.8 vs 0 pg/mL, respectively; p = 0.20) . CONCLUSIONS: Smoking one pack of cigarettes per day delivers a dose of respirable LPS that is comparable to the levels of LPS associated with adverse health effects in cotton textile workers . Thus, we suggest that the bioactive LPS in cigarette smoke may contribute to the pathogenesis of chronic bronchitis that develops in susceptible cigarette smokers. FEMS Microbiol Lett, 1999 Feb 15, 171(2), 73 - 9 Bacterial alpha-glucan phosphorylases; Schinzel R et al.; Although glycogen and other alpha-1,4-D-glucan storage polysaccharides are present in many bacteria, only few glucan phosphorylases from bacteria have been identified and characterised on the protein or gene level . All bacterial phosphorylases follow the same catalytic mechanisms as their plant and vertebrate counterparts, but differ considerably in terms of their substrate specificity and regulation . The catalytic domains are highly conserved while the regulatory sites are only poorly conserved . The degree of conservation between bacterial and mammalian phosphorylases is comparable to that of other non-mammalian and mammalian alpha-glucan phosphorylases . Only for maltodextrin phosphorylase from E . coli the physiological role of the enzyme in the utilisation of maltodextrins is known in detail; that of all other phosphorylases remains still unclear . Roles in regulation of endogenous glycogen metabolism in periods of starvation, and sporulation, stress response or quick adaptation to changing environments are imaginable. J Virol, 1999 Apr, 73(4), 2650 - 7 Bacterial lipopolysaccharide inhibits dengue virus infection of primary human monocytes/macrophages by blockade of virus entry via a CD14-dependent mechanism; Chen YC et al.; Monocytes/macrophages (MO/Mphi) are the major target cells for both dengue virus (DV) and bacterial lipopolysaccharide (LPS), and the aim of this study was to define their interactions . We had found that LPS markedly suppressed DV infection of primary human MO/Mphi when it was added to cultures prior to or together with, but not after, viral adsorption . The inhibitory effect of LPS was direct and specific and was not mediated by LPS-induced secretion of cytokines and chemokines such as tumor necrosis factor alpha, interleukin-1beta (IL-1beta), IL-6, IL-8, IL-12, alpha interferon, MIP-1alpha, and RANTES . In fact, productive DV infection was not blocked but was just postponed by LPS, with a time lag equal to one viral replication cycle . Time course studies demonstrated that LPS was only effective in suppressing DV infection of MO/Mphi that had not been previously exposed to the virus . At various time points after viral adsorption, the level of unbound viruses that remained free in the culture supernatants of LPS-pretreated cultures was much higher than that of untreated controls . These observations suggest that the LPS-induced suppression of DV replication was at the level of virus attachment and/or entry . Blockade of the major LPS receptor, CD14, with monoclonal antibodies MY4 or MoS39 failed to inhibit DV infection but could totally abrogate the inhibitory effect of LPS . Moreover, human serum could significantly enhance the LPS-induced DV suppression in a CD14-dependent manner, indicating that the "binding" of LPS to CD14 was critical for the induction of virus inhibition . Taken together, our results suggest that LPS blocked DV entry into human MO/Mphi via its receptor CD14 and that a CD14-associated cell surface structure may be essential for the initiation of a DV infection. J Immunol, 1999 Mar 1, 162(5), 2931 - 8 Bacterial lipopolysaccharide causes rapid shedding, followed by inhibition of mRNA expression, of the IL-1 type II receptor, with concomitant up-regulation of the type I receptor and induction of incompletely spliced transcripts; Penton-Rol G et al.; The IL-1 type I receptor (IL-1RI) is part of a signaling complex together with the IL-1R accessory protein, whereas available information is consistent with a "decoy" model of function for the IL-1 type II receptor (IL-1RII) . The present study was designed to investigate the effect of bacterial LPS on IL-1R in human monocytes . LPS causes rapid release of the IL-1RII, an effect blocked by a metalloprotease inhibitor . Subsequently, LPS-treated monocytes showed a drastic reduction of IL-1RII mRNA . In contrast, LPS induced IL-1RI and, to a lesser extent, IL-1AcP expression . LPS-induced augmented expression of the canonical 5-kb IL-1RI mRNA was accompanied by the appearance of 2.4-kb IL-1RI transcripts . The use of probes representative of different regions of the IL-1RI mRNA, as well as cDNA cloning, revealed that the 2.4-kb inducible band includes incompletely spliced, polyadenylated transcripts potentially encoding truncated versions of the receptor . The observation that the prototypic proinflammatory molecule LPS has divergent effects on IL-1Rs, with inhibition of IL-1RII and stimulation of IL-1RI and IL-1R accessory protein, is consistent with the view that these molecules subserve opposite functions in the pathophysiology of the IL-1 system . The rapid shedding of IL-1RII by monocytes early in recruitment may serve to buffer the systemic action of IL-1 leaking from sites of inflammation . This early event, followed by prolonged inhibition of IL-1RII expression and up-regulation of IL-1RI, may render monocytes more responsive to IL-1 at sites of inflammation. J Protein Chem, 1999 Jan, 18(1), 127 - 36 Properties of soluble fusions between mammalian aspartic proteinases and bacterial maltose-binding protein; Sachdev D et al.; The mammalian aspartic proteinases procathepsin D and pepsinogen form insoluble inclusion bodies when expressed in bacteria . They become soluble but nonnative when synthesized as fusions to the carboxy terminus of E . coli maltose-binding protein (MBP) . Since these nonnative states of the two aspartic proteinases showed no tendency to form insoluble aggregates, their biophysical properties were analyzed . The MBP portions were properly folded as shown by binding to amylose, but the aspartic proteinase moieties failed to bind pepstatin and lacked enzymatic activity, indicating that they were not correctly folded . When treated with proteinase K, only the MBP portion of the fusions was resistant to proteolysis . The fusion between MBP and cathepsin D had increased hydrophobic surface exposure compared to the two unfused partners, as determined by bis-ANS binding . Ultracentrifugal sedimentation analysis of MBP-procathepsin D and MBP-pepsinogen revealed species with very large and heterogeneous sedimentation values . Refolding of the fusions from 8 M urea generated proteins no larger than dimers . Refolded MBP-pepsinogen was proteolytically active, while only a few percent of renatured MBP-procathepsin D was obtained . The results suggest that MBP-aspartic proteinase fusions can provide a source of soluble but nonnative folding states of the mammalian polypeptides in the absence of aggregation. Br J Neurosurg, 1998 Oct, 12(5), 440 - 4 Embolic bacterial aneurysm of the basilar artery: case report; Roberts G et al.; A patient with basilar artery rupture caused by a septic embolus originating from a mitral valve vegetation is reported . The pathogenesis, investigation and management of infected cerebral aneurysms are reviewed. Trends Microbiol, 1999 Jan, 7(1), 16 - 22 Throwing the switch in bacterial chemotaxis; Silversmith RE et al.; In Escherichia coli chemotaxis, the switch from counterclockwise to clockwise rotation of the flagella occurs as a result of binding of the phosphorylated CheY protein to the base of the flagellum . Analysis of CheY variants has provided a picture of the surface of CheY that undergoes conformational shifts, as a result of phosphorylation, to interact directly with the flagellum . Whether phospho-CheY binding and flagellar switching are sequential steps or can occur in a concerted fashion has yet to be determined. J Surg Res, 1999 Mar, 82(1), 106 - 11 Glycyl-glutamine-enriched long-term total parenteral nutrition attenuates bacterial translocation following small bowel transplantation in the pig; Li YS et al.; BACKGROUND: Improvements in immunosuppression, operative procedure, and posttransplant management have made clinical small bowel transplantation (SBT) feasible . Ischemia and reperfusion injury, total parenteral nutrition (TPN), and devoidment of enteral feeding lead to graft atrophy, gut barrier dysfunction, and bacterial translocation . Glutamine (Gln) is the principal fuel for the enterocyte . The influence of Gln dipeptide-supplemented TPN, especially long-term TPN, on intestinal graft permeability and bacterial translocation is not clear following SBT in the large animal model . Therefore, we studied the effect of glutamine dipeptide, glycyl-glutamine (Gly-Gln), on bacterial translocation following SBT in the pig, which has a physiology similar to humans . MATERIALS AND METHODS: The outbred pigs underwent segmental small bowel autotransplantation and were divided into two groups . In the STPN group (n = 5), the animal received standard TPN devoid of Gly-Gln for 28 days . In the GTPN group (n = 5), the animal received isonitrogenous (0.3 g/kg.day) and isocaloric (33 kcal/kg.day) TPN solution with 2% Gly-Gln for 28 days . RESULTS: At the end of the experiment, Gly-Gln-enriched TPN could maintain the plasma Gln level, graft mucosal Gln and protein concentrations, and skeletal muscle Gln and protein concentrations . Gly-Gln-enriched TPN significantly decreased the bacterial number of mesenteric lymph nodes in the liver and spleen and intestinal permeability to 99mTc-DTPA . There were no significant differences in body weight gain . CONCLUSIONS: The Gly-Gln-enriched long-term TPN may maintain the plasma Gln level, mucosal and muscle Gln, and protein concentrations and attenuate the intestinal permeability to 99mTc-DTPA and bacterial translocation following small bowel transplantation in the pig . Curr Opin Microbiol, 1998 Oct, 1(5), 509 - 15 Bacterial enzymatic resistance: beta-lactamases and aminoglycoside-modifying enzymes; Bush K et al.; Numerous novel beta-lactamases and aminoglycoside-modifying enzymes with altered substrate profiles continue to be identified . Plasmid-mediated transmission of many of these enzymes readily occurs due to inclusion of the encoding genes in mobile gene cassettes . Recent crystallographic determinations of the structures of metallo-beta-lactamases and aminoglycoside-modifying enzymes provide the opportunity for the rational design of inhibitors. Curr Opin Microbiol, 1998 Oct, 1(5), 572 - 9 Mycoplasma pneumoniae and Mycoplasma genitalium: a comparison of two closely related bacterial species; Herrmann R et al.; The rapid progress in sequencing large quantities of DNA will provide an increasing number of complete genome sequences of closely related bacterial species as well as of pairs of isolates from the same species with different features, such as a pathogenic and an apathogenic representative . This opens the way to apply subtractive comparative analysis as a tool to select from the large pool of all bacterial genes a relatively small set of genes that can be correlated with the expression of a certain phenotype . These selected genes can then be the target for further functional analyses. J Pediatr Gastroenterol Nutr, 1999 Mar, 28(3), 296 - 300 Helicobacter pylori and nonulcer dyspepsia in childhood: clinical pattern, diagnostic techniques, and bacterial strains; Rutigliano V et al.; BACKGROUND: This is a report of the results of a multicenter study performed in children with dyspepsia from five pediatric centers in Puglia, a region in southern Italy . In the study, clinical features of Helicobacter pylori infection, the reliability of diagnostic techniques, and the involvement of bacterial strains were examined . METHODS: Fifty-three outpatients with dyspepsia enrolled in our study and compiled a diary recording clinical symptoms in patients before they underwent the following diagnostic techniques: endoscopy, biopsy for histologic analysis, rapid urease test, 13C urea breath test, serology specific for immunoglobulin (Ig)G and anti-CagA and VacA . RESULTS: H . pylori showed a prevalence of 30.2% (n = 16) . Histologic positivity was seen in all patients at the antral level (H . pylori-associated chronic gastritis) . In the gastric body, bacterial chronic active gastritis was present only in six patients (H . pylori-associated chronic pangastritis) . Clinical evaluation showed a significant difference in favor of subjects positive for H . pylori only for epigastric burning and/or pain (p < 0.001) . The comparison of results of diagnostic tests, using histology as the gold standard, showed sensitivity and specificity of more than 93% for 13C urea breath test and more than 85% for rapid urease test and serology . Anti-CagA antibodies were found in 64.3% and anti-VacA antibodies in 42.8% of H . pylori-positive patients . CONCLUSIONS: H . pylori prevalence in children with dyspepsia from the geographic area studied is comparable with that found in other developed countries . Approximately 50% of the studied patients were infected by cytotoxic strains . The urea breath test was the most reliable noninvasive diagnostic tool and is suitable for routine use, although endoscopy with histologic assessment remains the definitive investigation and is particularly important in patients with positive serology for CagA and VacA . Finally, the frequency of aggressive strains in our region seems to affect the clinical pattern; this emphasizes the importance of definitive diagnosis in children and offers a new role for serology. Microbiol Mol Biol Rev, 1999 Mar, 63(1), 161 - 73 Protein targeting to the bacterial cytoplasmic membrane; Fekkes P et al.; Proteins that perform their activity within the cytoplasmic membrane or outside this cell boundary must be targeted to the translocation site prior to their insertion and/or translocation . In bacteria, several targeting routes are known; the SecB- and the signal recognition particle-dependent pathways are the best characterized . Recently, evidence for the existence of a third major route, the twin-Arg pathway, was gathered . Proteins that use either one of these three different pathways possess special features that enable their specific interaction with the components of the targeting routes . Such targeting information is often contained in an N-terminal extension, the signal sequence, but can also be found within the mature domain of the targeted protein . Once the nascent chain starts to emerge from the ribosome, competition for the protein between different targeting factors begins . After recognition and binding, the targeting factor delivers the protein to the translocation sites at the cytoplasmic membrane . Only by means of a specific interaction between the targeting component and its receptor is the cargo released for further processing and translocation . This mechanism ensures the high-fidelity targeting of premembrane and membrane proteins to the translocation site. Clin Diagn Lab Immunol, 1999 Mar, 6(2), 247 - 53 Predictive value of CD19 measurements for bacterial infections in children infected with human immunodeficiency virus; Betensky RA et al.; We investigated the predictive value of CD19 cell percentages (CD19%) for times to bacterial infections, using data from six pediatric AIDS Clinical Trials Group protocols and adjusting for other potentially prognostic variables, such as CD4%, CD8%, immunoglobulin (IgA) level, lymphocyte count, prior infections, prior zidovudine treatment, and age . In addition, we explored the combined effects of CD19% and IgG level in predicting time to infection . We found that a low CD19% is associated with a nonsignificant 1.2-fold increase in hazard of bacterial infection (95% confidence interval: 0.97, 1.49) . In contrast, a high IgG level is associated with a nonsignificant 0.87-fold decrease in hazard of infection (95% confidence interval: 0.68, 1.12) . CD4% was more prognostic of time to bacterial infection than CD19% or IgG level . Low CD19% and high IgG levels together lead to a significant (P < 0 . 01) 0.50-fold decrease in hazard (95% confidence interval: 0.35, 0 . 73) relative to low CD19% and low IgG levels . Similarly, in a model involving assay result changes (from baseline to 6 months) as well as baseline values, the effect of CD19% by itself is reversed from its effect in conjunction with IgG . In this model, CD19% that are increasing and high are associated with decreases in hazard of infection (P < 0.01), while increasing CD19% and increasing IgG levels are associated with significant (at the P = 0.01 level) fourfold increases in hazard of infection relative to stable CD19% and decreasing, stable, or increasing IgG levels . Our data suggest that CD19%, in conjunction with IgG level, provides a useful prognostic tool for bacterial infections . It is highly likely that T-helper function impacts on B-cell function; thus, inclusion of CD4% in such analyses may greatly enhance the assessment of risk for bacterial infection. Curr Opin Microbiol, 1998 Apr, 1(2), 210 - 5 The regulation of bacterial cell division: a time and place for it; Lutkenhaus J; Temporal and spatial regulation of cell division assures that each daughter cell receives a copy of the chromosome . Within the past year, the application of fluorescence microscopy to the cell biology of bacteria has revealed an increasing number of proteins that are localized within the bacterial cell to carry out DNA segregation and cell division . The localization of these proteins implies the existence of positional information in the cell, but how this information is established is unknown. Curr Opin Microbiol, 1998 Apr, 1(2), 248 - 53 Bacterial solute uptake and efflux systems; Lolkema JS et al.; The recent discovery of binding protein dependent secondary transporters and the ever-growing family of membrane potential generating secondary transporters emphasize the diversity of transport systems in both the mechanistical and physiological sense . The vast amount of data on the lactose permease is now beginning to crystallize in a model that relates functional events to structural changes of the protein . Evidence has been presented that multidrug transporters pick up their substrates from the membrane, and the binding of a number of substrates to the binding-protein components of ATP-driven transporters is now understood in detail. Curr Opin Microbiol, 1998 Apr, 1(2), 145 - 51 Some repressors of bacterial transcription; Muller-Hill B; For a long time, repression of transcription in Escherichia coli was thought to be generally caused by one repressor binding to one operator . Recent work has indicated the frequent presence of auxiliary operators and helper proteins . The recent solution of the X-ray structures of Lac and Pur repressors were breakthroughs; yet, it has become painfully clear that important aspects of repression are still not understood. Curr Opin Microbiol, 1998 Feb, 1(1), 96 - 102 Helicobacter pylori: molecular evolution of a bacterial quasi-species; Covacci A et al.; Helicobacter pylori persists chronically within individuals and as they spread the mutating bacteria migrate with them . The continuous selection and microevolution generates a population of closely related but different bacteria that behave like a quasi-species . Within this heterogeneity, H . pylori strains fall into distinct types, into the virulent (type I) and less virulent (type II) strains, based on the presence of a pathogenicity island (cag) that encodes a specialized secretion machinery . We propose that during chronic infection a dynamic equilibrium between bacteria expressing a disparate degree of virulence is established, and that diverse forms prevail at different times. J Mol Biol, 1999 Mar 12, 286(5), 1471 - 85 An irregular beta-bulge common to a group of bacterial RNases is an important determinant of stability and function in barnase; Axe DD et al.; Single amino acid residue substitutions rarely destroy the structural integrity of proteins . Substitution of glycine residues, however, is among the few sorts of alterations that can have such an effect . Here, we seek to understand what accounts for the extreme functional impairment of the bacterial ribonuclease barnase upon substitution of Gly52 or Gly53 . We find that inactivation is caused by overall disruption of the folded state that manifests itself in three ways: (1) dramatically reduced stability (by 5.2 to 8.4 kcal mol-1 for mutants showing inactivation in vivo); (2) progressive loss of folded-state activity with increasing temperature, indicating a less well formed fold; and (3) substantial proteolytic degradation of mutant enzymes in vivo . Examination of two deletion mutants, missing either Gly53 or Asp54, shows that the irregular beta-bulge formed by these two residues is of vital importance to the structural integrity of barnase . The parallel behaviour of mutants carrying replacements of either of the two glycine residues therefore appears to arise from a common mechanism: disruption of local structure at the beta-bulge . The importance of this structural element to the function of barnase raises the question of whether it may be present in other RNases . The Streptomyces enzymes RNase Sa and RNase St differ considerably from barnase in both sequence and structure, yet both show significant sequence similarity to barnase over a region beginning at Gly53 . Structural comparison indicates that the Streptomyces enzymes do have the barnase-like irregular beta-bulge, making this an important characteristic feature of a group of bacterial ribonucleases . The sensitivity of this feature demonstrates that detailed aspects of local structure may have a major role in determining the overall structural and functional properties of an enzyme, even where no explanation for this role is readily apparent . If this is a general characteristic of the structure-function relationship, it may pose a formidable obstacle to the de novo design of new enzymes . J Mol Biol, 1999 Mar 12, 286(5), 1365 - 78 A three-way junction and constituent stem-loops as the stimulator for programmed -1 frameshifting in bacterial insertion sequence IS911; Rettberg CC et al.; Several signals are required for the programmed frameshifting in translation of IS911 mRNA . These include a Shine Dalgarno (SD)-like sequence, a slippery sequence of six adenine residues and a guanine residue (A6G) and a 3' secondary structure . The structure of the mRNA containing these elements was investigated using chemical and enzymatic probing . The probing data show that the 3' structure is a three-way junction of stems . The function of the three-way junction was investigated by mutagenesis . Disrupting the stability of the structure greatly affects frameshifting and transposition levels as tested by separate in vivo assays . Structural probing and thermal melting profiles indicate that the disrupted three-way junctions have altered structures . J Mol Biol, 1999 Mar 12, 286(5), 1275 - 84 Inversion of thermosensing property of the bacterial receptor Tar by mutations in the second transmembrane region; Nishiyama S et al.; The aspartate chemoreceptor Tar of Escherichia coli serves as a warm sensor that produces attractant and repellent signals upon increases and decreases in temperature, respectively . However, increased levels of methylation of the cytoplasmic domain of Tar resulting from aspartate binding convert Tar to a cold sensor with the opposite signaling behavior . Detailed analyses of the methylation sites, which are located in two separate alpha-helices (MH1 and MH2), have suggested that intra- and/or intersubunit interactions of MH1 and MH2 play a critical role in thermosensing . These interactions may be influenced by binding of aspartate, which could trigger some displacement of MH1 through the second transmembrane region (TM2) . As an initial step toward understanding the role of TM2 in thermosensing, we have examined the thermosensing properties of 43 mutant Tar receptors with randomized TM2 sequences (residues 190-210) . Among them, we identified one mutant receptor (Tar-I2) that functioned as a cold sensor in the absence of aspartate . This is the first example of attractant-independent inversion of thermosensing in Tar . Further analyses identified the minimal essential divergence from the wild-type Tar sequence (Q191V-W192R-Q193C) required for the inverted response . Thus, displacements of TM2 seem to influence the thermosensing function of Tar . Eur J Immunol, 1999 Feb, 29(2), 499 - 511 Distinct regulation of HLA class II and class I cell surface expression in the THP-1 macrophage cell line after bacterial phagocytosis; De Lerma Barbaro A et al.; Expression of HLA and CD1b molecules was investigated in the THP-1 macrophage cell line within 2 weeks following phagocytosis of mycobacteria or Escherichia coli . During the first 2-3 days, cell surface expression of HLA class II and CD1b was drastically down-modulated, whereas HLA class I expression was up-modulated . In the following days both HLA class II and CD1b expression first returned to normal, then increased and finally returned to normal with kinetics similar to that observed for the steadily increased HLA class I . The initial down-modulation of HLA class II and CD1b cell surface antigens was absolutely dependent on phagocytosis of bacteria . Further studies indicated that initial HLA class II cell surface down-modulation (1) was not due to reduced transcription or biosynthesis of mature HLA class II heterodimers, (2) was only partially, if at all, rescued by treatment with IFN-gamma, although both mRNA and corresponding intracellular proteins increased up to sixfold with respect to untreated cells, and (3) resulted in failure of THP-1 cells to process and present mycobacterial antigens to HLA-DR-restricted antigen-specific T cell lines . The existence of a transient block of transport of mature HLA class II heterodimers to the cell surface in the first days after phagocytosis of bacteria may have negative and positive consequences: it decreases APC function early but it may increase it later by favoring optimal loading of bacterial antigens in cellular compartments at high concentration of antigen-presenting molecules. Appl Environ Microbiol, 1999 Mar, 65(3), 1045 - 9 Polynucleotide probes that target a hypervariable region of 16S rRNA genes to identify bacterial isolates corresponding to bands of community fingerprints; Heuer H et al.; Temperature gradient gel electrophoresis (TGGE) is well suited for fingerprinting bacterial communities by separating PCR-amplified fragments of 16S rRNA genes (16S ribosomal DNA {rDNA}) . A strategy was developed and was generally applicable for linking 16S rDNA from community fingerprints to pure culture isolates from the same habitat . For this, digoxigenin-labeled polynucleotide probes were generated by PCR, using bands excised from TGGE community fingerprints as a template, and applied in hybridizations with dot blotted 16S rDNA amplified from bacterial isolates . Within 16S rDNA, the hypervariable V6 region, corresponding to positions 984 to 1047 (Escherichia coli 16S rDNA sequence), which is a subset of the region used for TGGE (positions 968 to 1401), best met the criteria of high phylogenetic variability, required for sufficient probe specificity, and closely flanking conserved priming sites for amplification . Removal of flanking conserved bases was necessary to enable the differentiation of closely related species . This was achieved by 5' exonuclease digestion, terminated by phosphorothioate bonds which were synthesized into the primers . The remaining complementary strand was removed by single-strand-specific digestion . Standard hybridization with truncated probes allowed differentiation of bacteria which differed by only two bases within the probe target site and 1.2% within the complete 16S rDNA . However, a truncated probe, derived from an excised TGGE band of a rhizosphere community, hybridized with three phylogenetically related isolates with identical V6 sequences . Only one of the isolates comigrated with the excised band in TGGE, which was shown to be due to identical sequences, demonstrating the utility of a combined TGGE and V6 probe approach. J Struct Biol, 1998 Dec 15, 124(2-3), 189 - 200 Structural analysis of bacterial chemotaxis proteins: components of a dynamic signaling system; Djordjevic S et al.; Most motile bacteria are capable of directing their movement in response to chemical gradients, a behavior known as chemotaxis . The signal transduction system that mediates chemotaxis in enteric bacteria consists of a set of six cytoplasmic proteins that couple stimuli sensed by a family of transmembrane receptors to behavioral responses generated by the flagellar motors . Signal transduction occurs via a phosphotransfer pathway involving a histidine protein kinase, CheA, and a response regulator protein, CheY, that in its phosphorylated state, modulates the direction of flagellar rotation . Two auxiliary proteins, CheW and CheZ, and two receptor modification enzymes, methylesterase CheB and methyltransferase CheR, influence the flux of phosphoryl groups within this central pathway . This paper focuses on structural characteristics of the four signaling proteins (CheA, CheY, CheB, and CheR) for which NMR or x-ray crystal structures have been determined . The proteins are examined with respect to their signaling activities that involve reversible protein modifications and transient assembly of macromolecular complexes . A variety of data suggest conformational flexibility of these proteins, a feature consistent with their multiple roles in a dynamic signaling pathway . J Struct Biol, 1998 Dec 15, 124(2-3), 123 - 8 Bacterial helicases; Egelman EH; Helicases are proteins that use the energy of ATP hydrolysis to open double-stranded DNA, RNA, or RNA-DNA hybrids into two single strands . Based upon sequence analysis, at least 12 helicases exist in Escherichia coli . We know that these proteins play important roles in DNA replication, recombination, repair, and transcription, as well as in RNA processing . Recent crystallographic studies have revealed a highly conserved catalytic core in the helicases, shared with the RecA protein and the F1-ATPase . However, evidence suggests that the functional divergence may be large . J Struct Biol, 1998 Dec 15, 124(2-3), 104 - 14 A structural feature in the central channel of the bacterial flagellar FliF ring complex is implicated in type III protein export; Suzuki H et al.; The FliF ring complex, which consists of the M-S ring and a proximal portion of the rod of the flagellar basal body, is the base structure for the bacterial flagellar assembly . The FliF ring is also thought to be part of the export apparatus for flagellar proteins from its amino acid sequence homology to proteins involved in type III protein export systems . We established a new purification procedure for the FliF ring particles and carried out electron microscopic image analyses in their two distinct forms: well-dispersed single particles in the presence of salt and ordered monolayer arrays of hexagonal packing formed in the absence of salt . In both cases, the axial projection maps showed a common feature, a pair of concentric rings: the inner ring corresponds to the proximal rod; the outer ring represents the thick, edge portion of the M-S ring . However, the central channel of the FliF ring, the putative pathway for the flagellar protein export, appeared to show distinct structural features in the two forms . This suggests that a domain of FliF partially occupies the central channel to be involved in the export and gate mechanism, and the domain changes its conformation depending on the ionic strength . Protein Expr Purif, 1999 Mar, 15(2), 162 - 70 Refolding, purification, and characterization of a loop deletion mutant of human Bcl-2 from bacterial inclusion bodies; Anderson M et al.; This report describes the cloning of recombinant human Bcl-2, in which the putative disordered loop region has been replaced with a flexible linker and the hydrophobic C-terminus has been replaced with a 6xHis tag (Bcl-2(6-32)-AAAA-Bcl-2(86-206)-HHHHHH, abbreviation rhBcl-2; amino acid numbering excludes the initiating methionine) . This protein was expressed in Escherichia coli where it accumulated in insoluble form in inclusion bodies . After lysis the washed inclusion bodies were solubilized and an l-arginine assisted protein refolding route was employed to obtain biologically active protein . rhBcl-2 was purified further by nickel chelate chromatography to give protein of >95% purity, with an overall yield of 5 mg per g of E . coli cell paste . Edman sequencing showed that approximately 90% of the rhBcl-2 retained the initiating methionine residue . Analytical size exclusion chromatography suggested that the refolded and purified rhBcl-2 was monomeric in nondenaturing solution . Purified protein had an affinity for a Bax BH3 domain peptide comparable to that for in vivo folded recombinant human Bcl-2 and suppressed caspase activation in a cell-free assay for apoptosis . 1H NMR spectroscopy of rhBcl-2, both free and complexed with the Bax BH3 domain peptide, provided further evidence for the structural and functional integrity of the refolded protein . These findings parallel and extend those of Muchmore et al., who found that a loop deletion mutant of human Bcl-XL retained anti-apoptotic function . Pediatr Infect Dis J, 1999 Feb, 18(2), 157 - 63 Evaluating children with respiratory tract infections: the role of immunization with bacterial polysaccharide vaccine; Wasserman RL et al.; Antibody deficiency syndromes are an important cause of recurrent infections in children . Today it is possible to perform a complete evaluation of antibody-mediated immunity leading to a definitive diagnosis of either normal or abnormal immunity in most patients . However, the interpretation of the results of IgG subclass determinations and specific antibody responses is still being defined . At this time our recommendation is that patients who meet the criteria for an evaluation of antibody-mediated immunity be referred to subspecialists trained in this evaluation until better criteria for normal have been developed . The possibility that protective amounts of antibodies against pneumococcal serotypes may develop only transiently must be considered in patients with recurrent infections after initial improvement after immunization, especially if IgG2 subclass deficiency is also present . In the future it may be possible to use a faster and more economical approach to evaluate patients with recurrent infections by immunization with pneumococcal vaccine and then measuring IgM, IgG and IgA along with postimmunization specific antipneumococcal antibody titers 4 to 6 weeks later . For this approach to become feasible, further studies comparing the information obtained from the evaluation of pre- and postimmunization antibody concentrations with that obtained from the evaluation of postimmunization concentrations alone are needed. J Antibiot (Tokyo), 1998 Dec, 51(12), 1099 - 104 Selective inhibition of the bacterial peptidoglycan biosynthesis by the new types of liposidomycins; Kimura K et al.; We examined the inhibitory activity against bacterial peptidoglycan biosynthesis, mammalian glycoprotein biosynthesis and growth of BALB/3T3 cells of four different types of liposidomycins which have the structure with or without sulfate and/or 3-methylglutaric acid moieties . Liposidomycins inhibited peptidoglycan biosynthesis about 30 to 500 times more effectively than tunicamycin, whereas liposidomycins inhibited mammalian glycoprotein biosynthesis about 30 to 300 times less effectively than tunicamycin . When the cytotoxic effect of liposidomycins and tunicamycin on the growth of mammalian cells were compared, liposidomycins did not show toxicity against BALB/3T3 cell at 25 microg/ml, though tunicamycin inhibited cell growth by 50% at 0.05 microg/ml . On the basis of these results, it is concluded that liposidomycins are selective antibiotics showing highly specific inhibition toward bacterial peptidoglycan biosynthesis. Nucleic Acids Res, 1999 Mar 15, 27(6), 1555 - 7 Rapid modification of bacterial artificial chromosomes by ET-recombination; Muyrers JP et al.; We present a method to modify bacterial artificial chromosomes (BACs) resident in their host strain . The method is based on homologous recombination by ET-cloning . We have successfully modified BACs at two distinct loci by recombination with a PCR product containing homology arms of 50 nt . The procedure we describe here is rapid, was found to work with high efficiency and should be applicable to any BAC modification desired. Am J Surg, 1999 Jan, 177(1), 38 - 41 Biliary bacterial infection decreased the secretion of bile acids and bilirubin into bile; Nishida T et al.; BACKGROUND: Bacterial cholangitis is frequently associated with serious complications . METHODS: The plasma disappearance rates and the biliary output of bile acids and bilirubin after percutaneous transhepatic biliary drainage (PTBD) were examined in 29 patients with extrahepatic biliary obstruction . RESULTS: Twenty-nine patients were divided into the bacteria-minus (n = 17) and bacteria-plus (n = 12) groups . Decreases in the plasma bile acid and bilirubin levels of the bacteria-minus group (t1/2 = 0.38 and 3.8 days for bile acids and bilirubin, respectively) were faster than those of the bacteria-plus group (t1/2 = 1.7 and 7.5 days) . The bile flow rate was significantly increased in the bacteria-plus group compared with the bacteria-minus group . The calculated values of bilirubin and bile acid in the bile were higher in the bacteria-minus group than in the bacteria-plus group . CONCLUSIONS: Bacterial colonization in the bile stimulates bile duct cells to increase bile volume and inhibits the hepatocyte transport activity of bile acids and bilirubin. Trends Microbiol, 1998 Dec, 6(12), 496 - 500 Bacterial DNA as immune cell activator; Lipford GB et al.; Pattern recognition receptors of the innate and adaptive immune systems apparently recognize unmethylated CpG motifs of bacterial DNA . Cells of the innate immune system are activated directly by CpG motifs, and the resulting response dictates a Th1 bias to the developing adaptive immune response . Interestingly, antigen receptor occupancy of cells of the adaptive immune system augments their responsiveness to CpG motifs, suggesting that co-stimulatory mechanisms are operative. Am J Respir Cell Mol Biol, 1999 Mar, 20(3), 493 - 9 Bacterial lipopolysaccharide induction of the prostaglandin G/H synthase 2 gene causes thromboxane-dependent pulmonary hypertension in rabbits; Delong P et al.; Two genes encode proteins with prostaglandin G/H synthase (PGHS) activity . PGHS-1 is primarily a constitutively expressed gene, whereas inflammatory agents such as bacterial lipopolysaccharide (LPS) endotoxin rapidly induce the PGHS-2 gene in leukocytes . Both PGHS-1 and PGHS-2 are rate-limiting enzymes for the production of prostaglandins and thromboxane following release of arachidonic acid by phospholipases . We previously reported that LPS perfusion into the circulation of isolated perfused rabbit lung (IPL) results in thromboxane-dependent pulmonary hypertension and lung edema when the LPS-primed lung is subsequently stimulated with platelet activating factor (PAF) (J . Clin . Invest . 1990;85:1135) . In this study, we showed that the mechanism by which LPS primes IPL for enhanced production of thromboxane and pulmonary hypertension in response to PAF depends on specific upregulation of the PGHS-2 gene in the rabbit lung . LPS perfusion of IPL induced PGHS-2 gene expression, which correlated with the conversion of free arachidonic acid to thromboxane-B2 (TXB2) and the onset of pulmonary hypertension . LPS-induced PGHS-2 expression, TXB2 release, and pulmonary hypertension were inhibited by actinomycin D (an inhibitor of transcription) and cycloheximide (an inhibitor of protein synthesis) . The constitutively expressed PGHS-1 remained unchanged with LPS perfusion, and did not convert free arachidonic acid to TXB2, suggesting that PGHS-1 does not contribute to the induction of pulmonary hypertension by LPS . These studies reveal a pathogenic role for induction of PGHS-2 in lung injury. FEMS Immunol Med Microbiol, 1999 Jan, 23(1), 67 - 73 A typical bacterial ornithine-containing lipid Nalpha-(D)-{3-(hexadecanoyloxy)hexadecanoyl}-ornithine is a strong stimulant for macrophages and a useful adjuvant; Kawai Y et al.; Nalpha-{3-(Hexadecanoyloxy)hexadecanoyl}-ornithine is a typical bacterial ornithine-containing lipid (OL) . The configuration of the 3-hydroxy fatty acids in the OL was proved to be D by using HPLC with chiral column . For this analysis, Nalpha-(D or L)-{3-(hexadecanoyloxy)hexadecanoyl}-L-ornithine were synthesized and used as standards . The typical bacterial OL, as well as the synthesized one, exhibited strong interleukin-1- and prostaglandin E2-inducing activities, and further, it induced the production of high IgG anti-tetanus toxoid antibodies in mice . The typical OL is expected to be utilized as a nontoxic, potent adjuvant. Vet J, 1999 Jan, 157(1), 85 - 9 A comparison of endoscopic and surgical collection procedures for the analysis of the bacterial flora in duodenal fluid from cats; Johnston KL et al.; In order to assess an endoscopic collection procedure, populations of bacteria in duodenal fluid from seven adult cats were compared in paired samples obtained by endoscopy and direct needle aspiration during laparotomy . Each sample of duodenal juice was subjected to quantitative and qualitative culture of bacteria under both aerobic and anaerobic conditions . There were no significant differences in total numbers or individual species of bacteria comparing the two collection procedures . These findings indicate that collection of duodenal juice by endoscopy using the procedure described provides a representative sample of small bowel fluid for the assessment of the bacterial flora . Therefore, there appears to be no need for more invasive or complicated sampling techniques when quantitative and qualitative culture of duodenal juice is indicated as part of an investigation of small bowel disease in cats. Fam Plann Perspect, 1999 Jan-Feb, 31(1), 4 - 9, 23 Correlates of sexually transmitted bacterial infections among U.S . women in 1995; Miller HG et al.; CONTEXT: Sexually transmitted diseases (STDs) of bacterial origin such as gonorrhea and chlamydial infection can lead to pelvic inflammatory disease (PID) and infertility . Identifying behaviors and characteristics associated with infection may assist in preventing these often asymptomatic diseases and their sequelae . METHODS: Data from 9,882 sexually active women who participated in the 1995 National Survey of Family Growth describe the characteristics of women who report a history of infection with a bacterial STD or of treatment for PID . Multivariate analysis is used to determine which demographic characteristics and sexual and health-related behaviors affect the likelihood of infection or the occurrence of complications . RESULTS: Overall, 6% of sexually active women reported a history of a bacterial STD, and 8% reported a history of PID . Women who first had sexual intercourse before age 15 were nearly four times as likely to report a bacterial STD, and more than twice as likely to report PID, as were women who first had sex after age 18 . Having more than five lifetime sexual partners also was associated with both having an STD and having PID . PID was more common among women reporting a history of a bacterial STD (23%) than among women who reported no such history (7%) . In multivariate analyses, age, race, age at first intercourse and lifetime number of sexual partners had a significant effect on the risk of a bacterial STD . Education, age, a history of IUD use, douching and a history of a bacterial STD had a significant impact on the risk of PID, but early onset of intercourse did not, and lifetime number of partners had only a marginal effect . CONCLUSIONS: The pattern of characteristics and behaviors that place women at risk of infection with bacterial STDs is not uniform among groups of women . Further, the level of self-reported PID would suggest higher rates of gonorrhea and chlamydial infection than reported. Clin Infect Dis, 1999 Jan, 28 Suppl 1, S57 - 65 Bacterial vaginosis: review of treatment options and potential clinical indications for therapy; Joesoef MR et al.; We reviewed data on the treatment of bacterial vaginosis published from 1993 through 1996 . For nonpregnant women, we recommend use of metronidazole (500 mg orally twice daily for 7 days), clindamycin vaginal cream (2%, once daily for 7 days), or metronidazole vaginal gel (0.75%, twice daily for 5 days) as the preferred treatment for bacterial vaginosis . For pregnant high-risk women (women with a prior preterm birth), the objective of the treatment is to prevent adverse outcomes of pregnancy, in addition to relief of symptoms . Thus, systemic therapy for possible subclinical upper tract infection as well as medication that has been studied in pregnant women are preferable . Therefore, we recommend metronidazole (250 mg orally three times a day for 7 days) . For pregnant low-risk women (women without a prior preterm birth) with symptomatic disease, the main objective of the treatment is to relieve symptoms . We recommend metronidazole (250 mg orally three times a day for 7 days) . Data do not support routine treatment of male sex partners. Pediatr Dermatol, 1999 Jan-Feb, 16(1), 19 - 22 Selective antibody deficiency to bacterial polysaccharide antigens in patients with Netherton syndrome; Stryk S et al.; Three patients with Netherton syndrome, recurrent sinopulmonary infections, and humoral immune deficiency are described . Although quantitative serum immunoglobulin levels were generally normal, two patients had selective antibody deficiency to bacterial polysaccharide antigens, one associated with IgA-IgG-2 deficiency . A third patient had an antibody deficiency to protein antigens . This is the first report, to our knowledge, that describes antibody deficiency in patients with Netherton syndrome . This finding demonstrates the importance of evaluating functional antibody responses to both protein and bacterial polysaccharide antigens and not relying on IgG subclass determination. Arthritis Rheum, 1999 Feb, 42(2), 210 - 20 Overexpression of human homologs of the bacterial DnaJ chaperone in the synovial tissue of patients with rheumatoid arthritis; Kurzik-Dumke U et al.; OBJECTIVE: To study the expression of the chaperone family of J proteins in the synovial tissue of patients with rheumatoid arthritis (RA) or osteoarthritis . METHODS: Rabbit antibodies specific for a synthetic peptide (pHSJ1: EAYEVLSDKHKREIYD), representing the most conserved part of all J domains thus far identified--among them the Drosophila tumor suppressor Tid56--were used in immunohistochemical analyses of frozen sections of synovial tissue and immunoblotting of protein extracts of adherent synovial cells . IgG specific for Tid56 was also used . RESULTS: Both antisera predominantly and intensely stained synovial lining cells from RA patients; other cells did not stain or stained only faintly . In immunoblots, anti-pHSJ1 specifically detected several bands with molecular weights of >74 kd (type I), 57-64 kd (type II), 41-48 kd (type III), and < or =36 kd (type IV) . The strongest band detected in RA adherent synovial cells was the type II band, whereas in a B cell line, a type I band was prominent . CONCLUSION: Several potentially new members of the J family are described . The type II band represents the human homolog of the Drosophila Tid56 protein and is strongly expressed in RA synovial tissue. No To Hattatsu, 1999 Jan, 31(1), 76 - 9 {Two cases of recurrent bacterial meningitis following traumatic cerebrospinal fluid rinorrhea}; Ikeda S et al.; We report here two cases of recurrent bacterial meningitis following traumatic cerebrospinal fluid rhinorrhea . Case-1: an 1-year-old girl had a penetrating injury to the nasal cavity with a chopstick . From 1 day after this accident, she had suffered from recurrent bacterial meningitis . She was diagnosed as having cerebrospinal fluid rhinorrhea, and underwent surgical repair of the bone defect . Case-2: a 5-year-old girl had suffered from bacterial meningitis 4 times after head trauma . A bone defect was demonstrated by 3-D CT and repaired surgically . We consider that 3-D CT is a useful tools to detect cerebrospinal fluid fistula. Infect Immun, 1999 Mar, 67(3), 1100 - 6 Transcutaneous immunization with bacterial ADP-ribosylating exotoxins as antigens and adjuvants; Glenn GM et al.; Transcutaneous immunization (TCI) is a new technique that uses the application of vaccine antigens in a solution on the skin to induce potent antibody responses without systemic or local toxicity . We have previously shown that cholera toxin (CT), a potent adjuvant for oral and nasal immunization, can induce both serum and mucosal immunoglobulin G (IgG) and IgA and protect against toxin-mediated mucosal disease when administered by the transcutaneous route . Additionally, CT acts as an adjuvant for coadministered antigens such as tetanus and diphtheria toxoids when applied to the skin . CT, a member of the bacterial ADP-ribosylating exotoxin (bARE) family, is most potent as an adjuvant when the A-B subunits are present and functional . We now show that TCI induces secondary antibody responses to coadministered antigens as well as to CT in response to boosting immunizations . IgG antibodies to coadministered antigens were also found in the stools and lung washes of immunized mice, suggesting that TCI may target mucosal pathogens . Mice immunized by the transcutaneous route with tetanus fragment C and CT developed anti-tetanus toxoid antibodies and were protected against systemic tetanus toxin challenge . We also show that bAREs, similarly organized as A-B subunits, as well as the B subunit of CT alone, induced antibody responses to themselves when given via TCI . Thus, TCI appears to induce potent, protective immune responses to both systemic and mucosal challenge and offers significant potential practical advantages for vaccine delivery. Lancet, 1999 Jan 9, 353(9147), 139 - 42 Bacterial infection in the pathogenesis of variceal bleeding; Goulis J et al.; Variceal bleeding is a life-threatening complication of cirrhosis . Potential risk factors include clinical, endoscopic, and haemodynamic factors, but why bleeding occurs unpredictably in individual patients is not known . We postulate that bacterial infections in patients with variceal haemorrhage may be the critical factor that triggers bleeding . In patients with large varices and a high wall tension, the release of endotoxin into the systemic circulation during episodes of bacterial infection results in a further increase in portal pressure through the induction of endothelin and possibly vasoconstrictive cyclo-oxygenase products . The subsequent contraction of hepatic stellate cells causes a rise in intrahepatic vascular resistance . Furthermore, endotoxin-induced nitric oxide and prostacyclin, and prostacyclin induced by endothelin could inhibit platelet aggregation, which may result in a further deterioration of primary haemostasis at the level of varix . We propose that the combination of these two effects leads to the onset of variceal haemorrhage. EMBO J, 1999 Feb 15, 18(4), 959 - 67 Anopheles gambiae Ag-STAT, a new insect member of the STAT family, is activated in response to bacterial infection; Barillas-Mury C et al.; A new insect member of the STAT family of transcription factors (Ag-STAT) has been cloned from the human malaria vector Anopheles gambiae . The domain involved in DNA interaction and the SH2 domain are well conserved . Ag-STAT is most similar to Drosophila D-STAT and to vertebrate STATs 5 and 6, constituting a proposed ancient class A of the STAT family . The mRNA is expressed at all developmental stages, and the protein is present in hemocytes, pericardial cells, midgut, skeletal muscle and fat body cells . There is no evidence of transcriptional activation following bacterial challenge . However, bacterial challenge results in nuclear translocation of Ag-STAT protein in fat body cells and induction of DNA-binding activity that recognizes a STAT target site . In vitro treatment with pervanadate (vanadate and H2O2) translocates Ag-STAT to the nucleus in midgut epithelial cells . This is the first evidence of direct participation of the STAT pathway in immune responses in insects. J Urol, 1999 Mar, 161(3), 964 - 9 Effects of bacterial endotoxin on the contraction and relaxation responses of the rabbit cavernous smooth muscles; Kim SC et al.; PURPOSE: We evaluated effects of bacterial endotoxin during septicemia on contraction and relaxation responses of cavernous smooth muscles in rabbits . MATERIALS AND METHODS: We performed isometric tension studies with norepinephrine (NE), endothelium-dependent and endothelium-independent vasodilators, and nonadrenergic noncholinergic (NANC)-selective electrical field stimulation on the muscle strips of control and endotoxin (lipopolysaccharide; LPS)-treated rabbits . To determine reversibility of the LPS effects on the cavernous smooth muscle, the contraction and relaxation studies were repeated after resting the strips for 1 day at 4C . We also investigated the effect of the nonspecific nitric oxide synthase (NOS) inhibitor (NW-nitro-L-arginine methyl ester; L-NAME) and the selective immunologic NOS inhibitor (aminoguanidine) on reactivity of the strips to NE and acetylcholine . RESULTS: Contractile response to NE was significantly (p <0.01) reduced in the cavernous smooth muscles from the systemically and locally LPS-treated rabbits, compared with control group . Both aminoguanidine and L-NAME markedly improved the diminished contraction of the strips . Relaxation response to endothelium-dependent agonists (acetylcholine and bradykinin) was significantly (p <0.05) decreased in the LPS-treated groups, compared with the control group but not to endothelium-independent vasodilators (papaverine and verapamil) and NANC-selective electrical field stimulation . L-NAME completely inhibited the relaxation response to acetylcholine in the control and LPS-treated groups but aminoguanidine did not . The impaired contraction and relaxation of the strips was completely restored after resting for 1 day . CONCLUSIONS: Bacterial endotoxin may cause non-endothelial overproduction of NO and inhibition of endothelium-derived NO production, which may contribute to impairment of contraction and relaxation of rabbit cavernous smooth muscles. Toxicol Lett, 1998 Dec 28, 102-103, 65 - 9 A transient brain ischemia- and bacterial endotoxin-induced glial iNOS expression and NO-induced neuronal apoptosis; Nomura Y; Astroglia cells seem to be closely involved in neuronal survival/death via neurotrophins, cytokines and so on . We found that a transient four-vessel occlusion/reperfusion induced glial iNOS expression and neuronal apoptosis in a CA1 region of the rat hippocampus . Bacterial endotoxin (LPS)/INFgamma induced iNOS expression in cultured C6 rat glioma cells . LPS caused intranuclear translocation of NF-kappaB, and IFNgamma induced phosphorylation of Jak2 and Stat1, followed by the translocation of Stat1 into the nucleus . A NO donor (SNP) caused chromosomal condensation and fragmentation of nuclei and internucleosomal DNA fragmentation in NG108-15 cells, suggesting NO-induced neuronal apoptosis . Koningic acid (KO), a chemical modifier and enzyme inhibitor of glyceraldehyde-3 phosphate dehydrogenase (GAPDH), induced the apoptosis too . In addition, a NO donor (NOC18)-induced apoptosis was inhibited by Z-Asp-CH2-DCB, a caspase inhibitor, in SH-SY5Y cells . NOC18 increased caspase 3-like proteolytic activity to a substrate (Ac-DEVD-MCA), indicating the involvement of caspase, at least caspase 3, in NO-induced neuronal apoptosis. Am J Trop Med Hyg, 1999 Jan, 60(1), 35 - 40 Bacterial expression of a neutralizing mouse monoclonal antibody Fab fragment to a 150-kilodalton surface antigen of Entamoeba histolytica; Tachibana H et al.; A mouse monoclonal antibody (MAb) (EH3015, IgG1 with a K light chain) prepared by hybridoma technology recognizes a 150-kD surface antigen of Entamoeba histolytica and inhibits adherence and cytotoxicity of the ameba to mammalian cells . The genes encoding the light chain and the Fd region of the heavy chain of the MAb were cloned and expressed in Escherichia coli . The plasmid used was designed for the expression of Fab with a hexa-histidine tag in the periplasmic space . Recombinant Fab fragments were purified and analyzed by an indirect immunofluorescence antibody test and Western immunoblot . The specificity of the recombinant Fab fragment was comparable with the parent whole IgG . In addition, the Fab fragments significantly inhibited the adherence of E . histolytica to erythrocytes . These results suggest that the production of a neutralizing MAb in Escherichia coli is practical and efficient with this expression system. Eur J Neurosci, 1999 Jan, 11(1), 178 - 86 Impaired glucocorticoid receptor function evolves in aberrant physiological responses to bacterial endotoxin; Linthorst AC et al.; The consequences of glucocorticoid receptor (GR) dysfunction for neuroimmunoendocrine responses to an inflammatory challenge were studied in transgenic mice expressing antisense RNA directed against the GR {GR-impaired (GR-i) mice} . Mice were implanted intraperitoneally with a biotelemetry transmitter to monitor body temperature and locomotion . GR-i mice showed decreased locomotion and body temperature during the dark phase of the diurnal cycle . Intraperitoneal administration of saline caused a rapid increase in body temperature in control mice, which was terminated within 90 min . In GR-i mice, however, body temperature remained elevated for about 6 h . Intraperitoneal injection of endotoxin (10 micrograms/mouse) produced a biphasic fever in control mice . However, in endotoxin-injected GR-i mice, body temperature was not significantly different from their saline-injected controls during the first 6 h . Body temperature then increased and remained elevated during the night period . Both strains showed hypolocomotion after endotoxin . In a second experiment, mice were injected intraperitoneally with saline or endotoxin and killed after 1, 3, 6 or 24 h . In GR-i mice, endotoxin caused an augmented rise in plasma ACTH, but not in corticosterone levels . The endotoxin-induced increase in serum levels of interleukin-1 beta and interleukin-6 was not different between the strains . However, whereas in control mice tumour necrosis factor-alpha levels were below detection at the time points studied, substantial levels of this cytokine were found in the serum of GR-i mice 1 h after endotoxin administration . It may be concluded that life-long impairment of GR evolves in aberrant physiological and humoral responses to an acute inflammatory challenge . These findings expand our understanding about the neuroendocrine and physiological disturbances associated with stress-related disorders. J Acquir Immune Defic Syndr Hum Retrovirol, 1999 Feb 1, 20(2), 201 - 6 Effect of trimethoprim-sulfamethoxazole as Pneumocystis carinii pneumonia prophylaxis on bacterial illness, Pneumocystis carinii pneumonia, and death in persons with AIDS; Buskin SE et al.; To measure the effect of trimethoprim-sulfamethoxazole (TMP-SMX) in preventing bacterial illness, Pneumocystis carinii pneumonia (PCP), and death in people with AIDS, we conducted a retrospective medical record review of 1078 persons who were observed for 3 years on average who attended nine outpatient facilities in Seattle, Washington between January 1990 and April 1996 . We calculated relative risk estimates to measure the protective effect of TMP-SMX on the development of major bacterial illnesses, PCP, and death . Use of TMP-SMX decreased the risk of PCP (relative risk {RR} = 0.23; 95% confidence interval {CI}, 0.14-0.36) and deaths not attributable to PCP (RR = 0.59; 95% CI, 0.47-0.73) . Prevention of major bacterial illnesses of known etiology was of borderline significance (RR = 0.77; 95% CI, 0.57-1.05) and became statistically significant with the addition of patients with infections of unknown etiology (RR = 0.77; 95% CI 0.61-0.97) . Use of TMP-SMX PCP prophylaxis significantly reduced the risks of death and of PCP and was associated with a trend toward reduced risk of major bacterial infections. J Immunol, 1999 Feb 15, 162(4), 1884 - 8 Cutting edge: chronic intestinal inflammation in STAT-4 transgenic mice: characterization of disease and adoptive transfer by TNF- plus IFN-gamma-producing CD4+ T cells that respond to bacterial antigens; Wirtz S et al.; We generated transgenic mice for STAT-4, a regulatory protein specifically associated with IL-12 signaling, under the control of a CMV promoter . These mice expressed strikingly increased nuclear STAT-4 levels in lamina propria CD4+ T lymphocytes upon systemic administration of dinitrophenyl-keyhole limpet hemocyanin and developed chronic transmural colitis characterized by infiltrates of mainly CD4+ T lymphocytes . The latter cells produced predominantly TNF and IFN-gamma but not IL-4 upon activation with alphaCD3/CD28 or autologous bacterial Ags, consistent with a Th1-type cell response . Furthermore, chronic colitis in STAT-4 transgenic mice could be adoptively transferred to SCID mice by colonic and splenic CD4+ T cells that were activated with Ags from autologous bacterial flora . These data establish a critical molecular signaling pathway involving STAT-4 for the pathogenesis of chronic intestinal inflammation, and targeting of this pathway may be relevant for the treatment of colitis in humans. J Electron Microsc (Tokyo), 1998, 47(6), 543 - 52 Characterization of the damage to membranes caused by bacterial cytolysins; Sekiya K et al.; The damage to cell membranes caused by bacterial cytolysins has been studied for many years . In this review, we attempt to summarize the historical contribution of electron microscopy to our understanding of the modes of action of pore-forming and channel-forming toxins . We describe the ways in which these toxins form holes in membranes by binding to and forming oligomers on biological membranes . We also introduce the new technique of electron spectroscopic imaging (ESI) with an imaging plate (IP), which has been used to analyse the mechanisms of membrane damage by cytolysins. Hepatogastroenterology, 1998 Nov-Dec, 45(24), 2165 - 70 Heavy bacterial loads of H . pylori may precipitate duodenal ulcer bleeding but not bleeding severity; Bor-Shyang S et al.; BACKGROUND/AIMS: To determine whether severity of Helicobacter pylori (H . pylori) infection is aggravated during acute duodenal ulcer bleeding and related to bleeding severity . METHODOLOGY: One hundred and thirty-eight patients with H . pylori-infected bleeding duodenal ulcer and 112 non-bleeding cases were included in the study . A comparison was made of the anti-H . pylori IgG titer, endoscopic finding, density of H . pylori (range: 1-5) in the antrum, and severity of antral gastritis (score: 0-3) between bleeding and non-bleeding cases . The role of H . pylori in bleeding cases was further analyzed to survey its relationship to the severity of bleeding judged by clinical parameters . The H . pylori status of patients with rebleeding within the first week was compared to that of the non-rebleeding cases as well . RESULTS: The anti-H . pylori IgG titer and H . pylori density of the non-bleeding group were lower than those of the bleeding group (0.466+/-0.288 vs . 0.912+/-0.559, p<0.001; 2.13+/-1.02 vs . 3.34+/-1.32, p<0.001) . The percentages of bleeding ulcers in the study cases increased in a trend as the density of H . pylori increased (density: 1-5; 32.7%, 33.8%, 57.4%, 81.3%, 91.4%, p<0.001) . Although the severity of gastritis and density of H . pylori disclosed an upward trend as bleeding severity increased, only ulcer size was significantly associated with bleeding severity (p<0.05) . The 10 cases with recurrent bleeding had higher bacterial density and serological titer than the 128 non-rebleeding cases (p<0.005) . CONCLUSIONS: Heavy bacterial loads of H . pylori infection may precipitate bleeding episodes of duodenal ulcer . However, in bleeding duodenal ulcer, the status of H . pylori infection is not strongly associated with initial bleeding severity before therapeutic endoscopy . With the aim of enhancing hemostasis and preventing rebleeding, further studies could focus on diminishing the bacterial load of H . pylori during bleeding episodes. Ter Arkh, 1998, 70(11), 72 - 4 {Clinico-biochemical effectiveness of emoxpine in patients with bacterial bronchial asthma}; Lapik SV et al.; AIM: To determine effectiveness of a synthetic antioxidant drug emoxipine in combined treatment of bacterial bronchial asthma (BBA) . MATERIALS AND METHODS: A total of 59 BBA patients were treated who had the disease for 1-14 years . The previous treatment consisted of bronchodilating, mucolytic and expectorant drugs . 19 of them received i.m . adjuvant emoxipine for 10 days in daily dose 0.3 mg/kg as a 1% aqueous solution . Metabolic activity of alveolar macrophages (AM) was measured . RESULTS: Emoxipine-treated patients had reduced content of primary lipid peroxidation products and schiff bases in AM, catalase level in them returned to normal, blood levels of alpha-tocopherol went up . CONCLUSION: Emoxipine is beneficial for AM antioxidant defence system in BBA patients. Surg Today, 1999, 29(1), 47 - 50 Hypertonic saline prevents early bacterial translocation in hemorrhagic shock; Topaloglu U et al.; The most appropriate solution for volume replacement in hemorrhagic shock is controversial; however, hypertonic saline (HTS) solutions have recently gained widespread acceptance . In this study, various solutions were used to resuscitate rats in hemorrhagic shock, and their impact on the extent of bacterial translocation was investigated . Rats were bled to a mean arterial blood pressure of about 35 mmHg which was maintained for 30 min . They were then randomized into six groups . Blood pressure was found to be regulated by blood + lactated Ringer's solution (LR) and HTS + LR, but no significant improvement was observed in the control and LR groups . Groups II (7.5% HTS + 60 ml/kg LR) and IV (60 ml/kg LR + autologous blood) had a significantly better result than groups I (7.5% HTS), III (60 ml/kg LR), and IV (P < 0.05), among which no statistically different results were seen (P > 0.05) . While no organisms were isolated from the mesenteric lymph nodes in the sham group, the rates of positive culture were 12.5%, 12.5%, 50%, 62.5%, and 62.5% in groups I, II, III, and the control group, respectively . Escherichia coli was the most commonly isolated organism . HTS + LR was demonstrated to be effective for decreasing the rate of early bacterial translocation to mesenteric lymph nodes and also for restoring the mean arterial pressure. Eur J Immunol, 1999 Jan, 29(1), 109 - 18 Neonatal colonization of rats induces immunological tolerance to bacterial antigens; Karlsson MR et al.; We wanted to investigate the immunological events occurring in rats intestinally colonized from birth (neonatally) or at adult age with an ovalbumin (OVA)-producing Escherichia coli O6K13 strain, carrying type 1 pili . The neonatally colonized animals responded with lower delayed type hypersensitivity (DTH) against OVA and lower levels of IgG antibodies against OVA, O6 lipopolysaccharide (LPS) and type 1 pili compared to age-matched controls . The IgG antibody response against the bystander antigen, human serum albumin (HSA), was lower in the neonatally colonized animals than in the controls co-immunized with HSA and E . coli, indicating a release of suppressive factors induced by the bacterial antigens . The adult colonized animals showed an increased DTH and antibody response against OVA after immunization . They also had high pre-immunization levels of IgG anti-O6 LPS antibodies compared to controls . However, the relative increase in IgG anti-O6 LPS antibody levels after the immunization with dead E . coli was much lower in the adult colonized animals . The present results suggest that neonatal animals develop tolerance against antigen on bacterial colonizers of the intestine . In addition, this tolerance contains components of suppression. Electrophoresis, 1998 Dec, 19(18), 3062 - 8 Preparative separation of plasmid and bacterial artificial chromosome DNA by density gradient electrophoresis in the presence of linear polymers; Cole KD; A density gradient apparatus was used to examine the separation of different physical forms and sizes of DNA . A gradient of sucrose was used to stabilize thermal convection during electrophoresis in the column (2.2 cm in diameter) . Linear polymers were added to the density gradient and screened for their ability to separate the supercoiled, nicked circular, and linear forms of the plasmid pBR 322 . The influence of different concentrations and molecular weights of the polymers was examined on the separation . Polyethylene oxide with a molecular weight of 5,000,000 and a concentration of 0.2% w/v achieved the best separation results for the different physical forms of the plasmid . The order of separation of the different physical forms of the plasmid were linear (fastest), supercoiled, and nicked circular (slowest) . These conditions were also used to separate a preparation of bacterial artificial chromosome (BAC) DNA . A rapidly moving form, presumably the supercoiled form, was resolved from a large amount of E . coli genomic DNA and from sheared forms of the BAC DNA. Acta Neurochir (Wien), 1998, 140(12), 1263 - 70 Current treatment strategies and factors influencing outcome in patients with bacterial brain abscess; Takeshita M et al.; We clearly determined the key to managing patients with brain abscess by retrospectively evaluating the factors affecting poor outcome in these patients . This study included 113 patients with brain abscess diagnosed in the CT era . Basic characteristics and therapeutic parameters were estimated as independent predictors of poor outcome by using univariate and multivariate logistic regression analysis . Patients with poor outcomes more frequently had deeply-located abscesses (p < 0.02), IVROBA (intraventricular rupture of brain abscess (p < 0.001) and were in a severely deteriorated neurological state (p < 0.001) than those with good outcomes . Multiple logistic regression analysis predicted that IVROBA (ORs, 24.5; 95% CI, 3.04 to 197.9) and severely deteriorated cases (ORs, 13.7; 95% CI, 2.34 to 80.8) resulting from IVROBA increased the relative risk of poor outcome . Patients with IVROBA more frequently had also deeply-located abscesses (p < 0.005), positively immunocompromised states (p < 0.05) and were in a severely deteriorated condition (p < 0.003) than those without IVROBA . Patients with metastatic abscess had also IVROBA (p < 0.006) . Multiple logistic regression analysis anticipated that deeply-located abscess (ORs, 3.90; 95% CI, 1.38 to 11.04), and metastatic abscess (ORs, 12.26; 95% CI, 1.35 to 111.2) increased the relative risk of IVROBA . Patients in an obtunded state and with marked neurological deficit had IVROBA more often than patients in an alert state and/or mild neurological deficit (ORs, 3.23; 95% CI, 1.17 to 8.86, p < 0.03) before treatment . Our findings suggest that IVROBA strongly influences poor outcome in patients with brain abscess . The key to decreasing poor outcomes may be the prevention and management of IVROBA, by evaluating intracranial pressure pathophysiology . IVROBA should be aggressively treated by aspiration methods for the abscess coupled with appropriate intravenous and intrathecial administration of antibiotics. Ann Otol Rhinol Laryngol, 1999 Jan, 108(1), 87 - 90 Carotid artery occlusion due to bacterial paranasal sinusitis; Ozuer MZ et al.; Complications of paranasal sinusitis still continue to be a serious health problem . We present an orbita-related complication of sinusitis in a patient with diabetic ketoacidosis . It was not a rhinocerebral mucormycosis, but a bacterial sinusitis-induced development of left cavernous sinus thrombophlebitis and carotid artery occlusion . We discuss the diagnosis, surgical options, and clinical outcome. Lipids, 1998 Dec, 33(12), 1213 - 6 Phytanic acid alpha-hydroxylation by bacterial cytochrome P450; Matsunaga I et al.; Fatty acid alpha-hydroxylase, a cytochrome P450 enzyme, from Sphingomonas paucimobilis, utilizes various straight-chain fatty acids as substrates . We investigated whether a recombinant fatty acid alpha-hydroxylase is able to metabolize phytanic acid, a methyl-branched fatty acid . When phytanic acid was incubated with the recombinant enzyme in the presence of H2O2, a reaction product was detected by gas chromatography, whereas a reaction product was not detected in the absence of H2O2 . When a heat-inactivated enzyme was used, a reaction product was not detected with any concentration of H2O2 . Analysis of the methylated product by gas chromatography-mass spectrometry revealed a fragmentation pattern of 2-hydroxyphytanic acid methyl ester . By single-ion monitoring, the mass ion and the characteristic fragmentation ions of 2-hydroxyphytanic acid methyl ester were detected at the retention time corresponding to the time of the product observed on the gas chromatogram . The Km value for phytanic acid was approximately 50 microM, which was similar to that for myristic acid, although the calculated Vmax for phytanic acid was about 15-fold lower than that for myristic acid . These results indicate that a bacterial cytochrome P450 is able to oxidize phytanic acid to form 2-hydroxyphytanic acid. Annu Rev Genet, 1998, 32, 339 - 77 The diverse and dynamic structure of bacterial genomes; Casjens S; Bacterial genome sizes, which range from 500 to 10,000 kbp, are within the current scope of operation of large-scale nucleotide sequence determination facilities . To date, 8 complete bacterial genomes have been sequenced, and at least 40 more will be completed in the near future . Such projects give wonderfully detailed information concerning the structure of the organism's genes and the overall organization of the sequenced genomes . It will be very important to put this incredible wealth of detail into a larger biological picture: How does this information apply to the genomes of related genera, related species, or even other individuals from the same species? Recent advances in pulsed-field gel electrophoretic technology have facilitated the construction of complete and accurate physical maps of bacterial chromosomes, and the many maps constructed in the past decade have revealed unexpected and substantial differences in genome size and organization even among closely related bacteria . This review focuses on this recently appreciated plasticity in structure of bacterial genomes, and diversity in genome size, replicon geometry, and chromosome number are discussed at inter- and intraspecies levels. Infect Control Hosp Epidemiol, 1999 Jan, 20(1), 58 - 60 Bacterial filters in anesthesia: results of 9 years of surveillance; van Hassel S et al.; In 9 years of surveillance of postoperative lower respiratory infections, the infection rate in patients following regional anesthesia was 0.2% and 0.1% in patients following general anesthesia . No bacterial filters in the breathing circuit were used . Infected patients had risk factors such as type of surgery, American Society of Anesthesiologists class > or =2, old age, chronic obstructive pulmonary disease, or smoking habits . Infections were not clustered . This suggests that, in our setting, patient factors are most important in the development of postoperative lower respiratory infections and that the role of bacterial filters as a preventive measure is negligible. Appl Environ Microbiol, 1999 Feb, 65(2), 732 - 6 Estimating bacterial growth parameters by means of detection times; Baranyi J et al.; We developed a new numerical method to estimate bacterial growth parameters by means of detection times generated by different initial counts . The observed detection times are subjected to a transformation involving the (unknown) maximum specific growth rate and the (known) ratios between the different inoculum sizes and the constant detectable level of counts . We present an analysis of variance (ANOVA) protocol based on a theoretical result according to which, if the specific rate used for the transformation is correct, the transformed values are scattered around the same mean irrespective of the original inoculum sizes . That mean, termed the physiological state of the inoculum, alpha, and the maximum specific growth rate, mu, can be estimated by minimizing the variance ratio of the ANOVA procedure . The lag time of the population can be calculated as lambda = -ln alpha/mu; i.e . the lag is inversely proportional to the maximum specific growth rate and depends on the initial physiological state of the population . The more accurately the cell number at the detection level is known, the better the estimate for the variance of the lag times of the individual cells. J Endocrinol, 1999 Feb, 160(2), 291 - 6 Effect of bacterial endotoxin on the in vitro release of Type II phospholipase-A2 and prostaglandin E2 from human placenta; Farrugia W et al.; The aim of this study was to establish the effect of bacterial endotoxin lipopolysaccharide (LPS) on the release of Type II phospholipase-A2 (PLA2) and prostaglandin E2 (PGE2) from late-pregnant human placental tissue incubated in vitro . Under basal conditions, immunoreactive Type II PLA2 and PGE2 were released from tissue explants in a time-dependent manner (up to 24 h, ANOVA, P<0 . 0001, n=6) . The release of these mediators was not associated with a loss of cell membrane integrity, as indicated by concentrations of the intracellular enzyme, lactate dehydrogenase (LDH), in the incubation medium . Incubation of explants in the presence of LPS (0 . 001-100 microg LPS/ml) significantly decreased PLA2 tissue content (P<0.02, n=6) and increased the accumulation of PLA2 and PGE2 in the incubation medium (P<0.0001, n=6) . The data obtained in this study indicated that Type II PLA2 and PGE2 are released from term placenta under basal conditions and that LPS stimulated their release . The associated decrease in PLA2 tissue content is consistent with the hypothesis that LPS induces the release of stored PLA2 . This study identifies one pathway by which products of bacterial infection may induce the release of a pro-inflammatory, extracellularly active PLA2 from intrauterine tissues that may promote the formation of phospholipid metabolites involved in the process of labour and delivery (e.g . the prostaglandins). Nature, 1999 Jan 14, 397(6715), 168 - 71 Robustness in bacterial chemotaxis; Alon U et al.; Networks of interacting proteins orchestrate the responses of living cells to a variety of external stimuli, but how sensitive is the functioning of these protein networks to variations in their biochemical parameters? One possibility is that to achieve appropriate function, the reaction rate constants and enzyme concentrations need to be adjusted in a precise manner, and any deviation from these 'fine-tuned' values ruins the network's performance . An alternative possibility is that key properties of biochemical networks are robust; that is, they are insensitive to the precise values of the biochemical parameters . Here we address this issue in experiments using chemotaxis of Escherichia coli, one of the best-characterized sensory systems . We focus on how response and adaptation to attractant signals vary with systematic changes in the intracellular concentration of the components of the chemotaxis network . We find that some properties, such as steady-state behaviour and adaptation time, show strong variations in response to varying protein concentrations . In contrast, the precision of adaptation is robust and does not vary with the protein concentrations . This is consistent with a recently proposed molecular mechanism for exact adaptation, where robustness is a direct consequence of the network's architecture. Acta Chir Belg, 1998 Dec, 98(6), 245 - 9 The effect of intestinal transit time on bacterial translocation; Erbil Y et al.; Increase in intraluminal bacterial count, disruption of the mucosal integrity, changes in intestinal immunity and transit time are the factors involved in bacterial translocation . The relationship between intestinal transit time, intra luminal bacterial count and translocation rate were investigated in 40 Wistar-albino rats . The study was conducted in 4 groups with 10 animals in each . Group I (controls): saline + laboratory chow, Group II: saline + oral total parenteral nutrition (TPN) solution, Group III: morphine sulfate (MS) + oral TPN solution, Group IV: neostigmine bromide (NB) + oral TPN solution . Intestinal transit time was measured by using Indium111-labeled diethylene triamine pentaacetic acid (DTPA) . It was prolonged in the MS-treated group and shortened in the NB-treated group (p < 0.01) . The frequency of bacterial translocation was 60% in the oral TPN solution group, 100% in the MS-treated group, 20% in the NB-treated group and 10% in controls . Bacterial counts in duodenum, jejunum, ileum and caecum were significantly increased (p < 0.001) in the MS-treated group and decreased (p < 0.05) in the NB-trea