Sci Total Environ, 1994 Sep 16, 154(2-3), 201 - 15 Pathology and toxicology of beluga whales from the St . Lawrence Estuary, Quebec, Canada . Past, present and future; Martineau D et al.; An indigenous population of 450-500 beluga whales (Delphinapterus leucas) inhabiting the St . Lawrence Estuary has been exposed chronically for more than 50 years to a complex mixture of industrial pollutants including organochlorinated compounds (OC), polycyclic aromatic hydrocarbons (PAH) and heavy metals . From 1983 to 1990, we have necropsied 45 well preserved carcasses out of a total of 120 beluga whales reported dead over this period . Of these 45 animals, nine were affected by 10 malignant neoplasms . Fifteen animals (33%) were affected by pneumonia . Milk production was compromised in eight of 17 mature females (41%), by inflammatory changes (seven animals) and cancer (one animal) which affected the mammary glands . Opportunistic bacteria were found in pure culture, and/or in significant amounts in at least two organs in 20 belugas (44%) . The concentrations of both total PCBs and highly chlorinated PCB congeners were much higher in St . Lawrence animals than in Arctic beluga whales . OC-induced immunosuppression has been repeatedly demonstrated in a wide variety of animal species . Therefore, it is probable that the immune functions of St . Lawrence beluga whales are impaired . Benzo{a}pyrene adducts were detected in 10 of the 11 St . Lawrence beluga whales of which tissues (six livers, 10/11 brains) were analyzed by a method based on HPLC . No such adducts were found in four Arctic animals . Since benzo{alpha}pyrene is one of the most potent chemical carcinogens known to man, these compounds might be responsible for some of the cancers observed in that population . Overall, our findings contrast vividly with those of others who found that cancers are exceedingly rare in free-ranging odontocete populations and that the major causes for mortalities in these populations are bacteria, parasites, and trauma. Biochem Biophys Res Commun, 1994 Sep 15, 203(2), 1181 - 7 E5510 antagonizes thrombin receptor signals by inhibiting NF-kappa B activation; Nakajima T et al.; We have recently demonstrated that NF-kappa B is involved in a thrombin-signaling and that the antisense oligodeoxynucleotides (ODNs) of NF-kappa B has a marked inhibitory effect on thrombin-induced cellular responses . In this study, we demonstrate that E5510 (4-cyano-5,5-bis(methoxyphenyl)-4-pentenoic acid), a compound with anti-platelet activity preferentially inhibits the thrombin-inducible NF-kappa B activation and then antagonizes the following thrombin-induced cellular responses, proliferation and cytokines production in vascular smooth muscle cell, and the adherency of differentiated HL-60 cells . These data suggest that E5510 is an anti-atherosclerotic or anti-restenotic drug induced by thrombin. J Biol Chem, 1994 Sep 9, 269(36), 22698 - 704 Identification of calmodulin-, Ca(2+)-, and ruthenium red-binding domains in the Ca2+ release channel (ryanodine receptor) of rabbit skeletal muscle sarcoplasmic reticulum; Chen SR et al.; cDNAs encoding trpE fusion proteins containing fragments of the skeletal muscle Ca2+ release channel (ryanodine receptor) were expressed in bacteria . The fusion proteins, which covered about 90% of the linear sequence of the ryanodine receptor, were used to identify calmodulin- (CaM), Ca(2+)-, and ruthenium red-binding regions in the ryanodine receptor through the use of 125I-CaM, 45Ca2+, and ruthenium red overlay procedures . Six Ca(2+)-dependent CaM-binding domains were detected in the skeletal muscle ryanodine receptor . Strong CaM-binding domains were localized in regions 6, 11, 12, and 13, in subregions 6b, 11b, and 13b, and in short sequences 6b3, 11b1, and 13b2, lying between amino acid residues 2063 and 2091, 3611 and 3642, and 4303 and 4328 . Weaker CaM-binding domains were localized in regions 4, 9, and 10 and in subregions 4b, 9b, and 10a, lying between residues 921 and 1173, 2804 and 2930, and 2961 and 3084 . Most of these CaM-binding domains encompassed all or part of previously predicted CaM-binding sites . Strong 45Ca(2+)- and ruthenium red-binding sites domains were localized in the NH2- and COOH-terminal regions of the ryanodine receptor and in regions 6, 12, and 13 . The 45Ca(2+- and ruthenium red-binding sites in regions 6 and 12 were localized in subregions 6b and 12b, lying between residues 1861-2094 and 3657-3776 . These data together with earlier studies (Chen, S . R . W., Zhang, L., and MacLennan, D . H . (1992) J . Biol . Chem . 267, 23318-23326), show that strong CaM-, Ca(2+)-, and ruthenium red-binding domains are colocalized in the skeletal muscle ryanodine receptor. Eur J Prosthodont Restor Dent, 1994 Sep, 3(1), 27 - 32 Pulp response to a novel adhesive calcium hydroxide based cement; Watts A et al.; This study compares pulp responses to 3 formulations of calcium hydroxide, namely: a) An experimental adhesive calcium hydroxide cement containing polyacrylic acid, b) Dycal (L.D> Caulk Co, Milford, Delaware) Batch Nos 176970/176990, c) "Analar" calcium hydroxide mixed with sterile distilled water . After 28 days dentine bridges were present in 77% of teeth capped with the test material, 64% of teeth treated with Dycal and in 62% of teeth capped with calcium hydroxide and water . Inflammatory infiltrates were observed in a number of teeth remote from the bridges . Bacteria were detected in these specimens . Exposed rat molar pulp responses to an experimental adhesive calcium hydroxide cement were similar to to those observed with 2 other calcium hydroxide formulations. Biochem J, 1994 Sep 1, 302 ( Pt 2), 587 - 93 Purification and properties of a novel cytochrome: flavocytochrome c from Shewanella putrefaciens; Morris CJ et al.; The major soluble cytochrome isolated from microaerobically grown cells of Shewanella putrefaciens has been shown to be a novel type of flavocytochrome with fumarate reductase activity . This flavocytochrome, located in the periplasmic fraction of cell extracts, has been purified to homogeneity and shown to contain 4 mol of haem c and 1 mol of non-covalently bound FAD per mol of protein . An M(r) value of 63,800 is estimated from sequence analysis assuming 4 mol of haem/mol of protein . In the presence of the artificial electron donor, reduced methyl viologen, the flavocytochrome catalysed the reduction of fumarate but not that of nitrite, dimethylsulphoxide, trimethylamine-N-oxide or sulphite . The pH optimum was 7.4 with calculated pKa values of 6.8 and 8.0 for contributing catalytic groups . The Km and kcat . values for fumarate reduction were 21 microM and 250 s-1 respectively, whereas the corresponding values for succinate oxidation with 2,6-dichlorophenol-indophenol as electron carriers were 200 microM and 0.07 s-1 respectively . Mesaconic acid was a competitive inhibitor of fumarate reduction with a Ki of 2 microM . Zymogram staining of polyacrylamide gels with purified protein showed a band of fumarate reductase activity . Polyclonal antibodies, raised to the purified flavocytochrome, were shown to titrate out fumarate reductase activity . We conclude that the physiological role of this enzyme is as a fumarate reductase . Optical absorption spectra of the flavocytochrome indicated that all the haems were of the c-type and gave alpha, beta and gamma peaks at 552.3, 523 and 418 nm in the reduced spectrum with epsilon values of 30.2, 15.9 and 188.2 mM-1.cm-1 respectively . Oxidized spectra showed no 695 nm band that would be indicative of His-Met coordination . Two redox potentials were resolved at -220 mV and -320 mV . The cytochrome was reduced by formate in the presence of particulate cell fractions . The relationship of this cytochrome to other low-potential flavocytochromes c is discussed. Ann Surg, 1994 Sep, 220(3), 353 - 60; discussion 360-3 Optimal therapy for stress gastritis; Maier RV et al.; OBJECTIVE: The authors compared the results of sucralfate versus H2 blocker +/- antacid as prophylaxis for stress ulceration in an intensive care unit patient population . SUMMARY BACKGROUND DATA: Stress ulceration carries high morbidity and mortality for the patient who is critically ill . Gastric acid neutralization is an effective prophylaxis . The impact of increased gastric colonization with bacterial pathogens on nosocomial pneumonia after acid neutralization is unclear . The efficacy of sucralfate prophylaxis for stress ulceration and its the effect on the nosocomial pneumonia rate is controversial . The financial implications of sucralfate prophylaxis versus H2 blocker-based acid neutralization therapy has not been studied . METHODS: Ninety-eight injured patients who were critically ill and who required intubation and intensive care unit (ICU) support for at least 72 hours without gastric feeding were randomized and received either maximal H2 blocker infusion therapy (continuous infusion of ranitidine at 0.25 mg/kg/hr after a loading dose of 0.5 mg/kg) plus antacids (for persistent pH < 4) or sucralfate (1 g every 6 hours via nasogastric tube) for stress ulcer prophylaxis . Efficacy in preventing stress ulcer complications was determined . The impact of each therapeutic approach on development of nosocomial pneumonia was evaluated . The charges/cost for each approach was analyzed . RESULTS: Heme-positive gastric aspirates occurred in 99% of the patients, whereas 12 (7 in the H2 blocker group and 5 in the sucralfate group) were grossly positive for blood . However, only one from each group required transfusion, and one in the H2 blocker group required operation . Gastric colonization preceded tracheobronchial colonization in five patients in the H2 blocker group and one patient in the sucralfate group; simultaneous gastric/oropharyngeal colonization preceded positive tracheobronchial growth in six patients who received H2 blocker and one patient who received sucralfate . The overall pneumonia rate was 27.5% in the H2 blocker group and 20.8% in the sucralfate group (p = 0.48) . Days on ventilator were 13.5 versus 9.1, (p = 0.06), ICU lengths of stay were 14.7 versus 10.2 (p = 0.06), and hospital lengths of stay were 27.8 versus 20.0 (p = 0.029) for the H2 blocker group and sucralfate group, respectively . Based on current charges and protocols for optimal H2 blocker and sucralfate prophylaxis, use of sucralfate rather than H2 blockers would decrease the annual cost by more than $30,000 per bed . CONCLUSIONS: Sucralfate is as efficacious as maximal H2 blocker therapy for stress ulceration prophylaxis, and may have a beneficial effect on the incidence of nosocomial pneumonia . Sucralfate has a major reduction on nursing requirements for stress ulcer prophylaxis and would save approximately $30,000 per ICU bed per year in patient charges. Invest Ophthalmol Vis Sci, 1994 Sep, 35(10), 3747 - 58 Bovine connexin44, a lens gap junction protein: molecular cloning, immunologic characterization, and functional expression; Gupta VK et al.; PURPOSE: To identify, clone molecularly, characterize immunochemically, and express functionally a bovine lens gap junction protein (connexin) . METHODS . The methods used were polymerase chain reaction, genomic cloning, RNA and DNA blotting, bacterial expression of a fusion protein, immunoblotting, alkaline phosphatase treatment, Xenopus oocyte expression, and voltage clamp technique . RESULTS . A bovine genomic clone encoding a polypeptide of 44,424 d, termed connexin44 (Cx44), was isolated . Cx44 was most closely related to the lens connexins rat Cx46 and chicken Cx56 . The Cx44 DNA hybridized to a 2.5 kb mRNA detected only in lens RNA . The carboxyl terminal 161 amino acids from Cx44 were expressed in bacteria fused to maltose binding protein (MBP) . The Cx44/MBP fusion protein reacted in immunoblots with anti-rat Cx46(411 to 416) antibodies and with the monoclonal antibody 5H1, but not with a monoclonal antibody to MP70 nor with antibodies to other connexins . Cx44 translated in vitro from the cloned DNA showed a single band with an apparent electrophoretic mobility of approximately 50 kd on polyacrylamide gels containing sodium dodecyl sulfate . Multiple bands of 53 to 57 kd were detected by immunoblotting in homogenates of bovine lens; these bands were reduced to a broad band of approximately 50 kd by alkaline phosphatase treatment, suggesting that they represented phosphorylated forms of Cx44 . Cx44 RNA injected in single oocytes induced a large and characteristic time- and voltage-dependent current . Overexpression of Cx44 produced depolarization and cell lysis . Junctional currents that could be regulated by transjunctional voltage were induced between paired oocytes injected with Cx44 RNA . Observations in paired oocytes suggested the assembly of hemichannels into junctional channels . CONCLUSIONS . Cx44 is a phosphoprotein component of bovine lens fiber gap junctions . Although it has a relatively distinct sequence, it shares sequence similarity, immunologic cross-reactivity, and electrophysiological properties with rat Cx46 . These data suggest that Cx44 is the protein previously identified in several immunohistochemical studies of bovine lens gap junctions that used anti-rat Cx46 antibodies . They also suggest that the formation of intercellular channels by pairing of hemichannels might prevent the cell lysis induced by the opening of unpaired hemichannels. J Bacteriol, 1994 Sep, 176(18), 5615 - 21 Mutations in the bvgA gene of Bordetella pertussis that differentially affect regulation of virulence determinants; Stibitz S; By using chemical mutagenesis and genetic mapping, a search was undertaken for previously undescribed genes which may be involved in different regulatory mechanisms governing different virulence factors of Bordetella pertussis . Previous studies have shown that the fha locus encoding filamentous hemagglutinin is regulated directly by the bvgAS two component system, while regulation of ptx encoding pertussis toxin is less direct or occurs by a different mechanism . With a strain containing gene fusions to each of these regulated loci, screening was done for mutations which were defective for ptx expression but maintained normal or nearly normal levels of fha expression . Two mutations which had such a phenotype and were also deficient in adenylate cyclase toxin/hemolysin expression were found and characterized more fully . Both were found to affect residues in the C-terminal portion of the BvgA response regulator protein, a domain which shares sequence similarity with a family of regulatory proteins including FixJ, UhpA, MalT, RcsA, RcsB, and LuxR . The residues affected are within a region which, by extension from studies on the LuxR protein, may be involved in transcriptional activation. Ann Emerg Med, 1994 Sep, 24(3), 457 - 61 Expedited detection of drug resistance in tuberculosis patients; Heifets LB; The increase in disease-causing organisms resistant to standard drug therapy has captured the attention of the medical community and the lay press . Drug resistance in rapidly growing bacteria can be detected within a short period . However, in the case of Mycobacterium tuberculosis, detection may take weeks . This paper examines the current methods available to determine drug susceptibility in M tuberculosis . These laboratory methods can be used as a model to assist the clinician in making rational decisions when managing patients with potentially resistant bacterial infections. J Bacteriol, 1994 Sep, 176(17), 5244 - 54 Phylogeny of mycoplasmalike organisms (phytoplasmas): a basis for their classification; Gundersen DE et al.; A global phylogenetic analysis using parsimony of 16S rRNA gene sequences from 46 mollicutes, 19 mycoplasmalike organisms (MLOs) (new trivial name, phytoplasmas), and several related bacteria placed the MLOs definitively among the members of the class Mollicutes and revealed that MLOs form a large discrete monophyletic clade, paraphyletic to the Acholeplasma species, within the Anaeroplasma clade . Within the MLO clade resolved in the global mollicutes phylogeny and a comprehensive MLO phylogeny derived by parsimony analyses of 16S rRNA gene sequences from 30 diverse MLOs representative of nearly all known distinct MLO groups, five major phylogenetic groups with a total of 11 distinct subclades (monophyletic groups or taxa) could be recognized . These MLO subclades (roman numerals) and designated type strains were as follows: i, Maryland aster yellows AY1; ii, apple proliferation AP-A; iii, peanut witches'-broom PnWB; iv, Canada peach X CX; v, rice yellow dwarf RYD; vi, pigeon pea witches'-broom PPWB; vii, palm lethal yellowing LY; viii, ash yellows AshY; ix, clover proliferation CP; x, elm yellows EY; and xi, loofah witches'-broom LfWB . The designations of subclades and their phylogenetic positions within the MLO clade were supported by a congruent phylogeny derived by parsimony analyses of ribosomal protein L22 gene sequences from most representative MLOs . On the basis of the phylogenies inferred in the present study, we propose that MLOs should be represented taxonomically at the minimal level of genus and that each phylogenetically distinct MLO subclade identified should represent at least a distinct species under this new genus. Infect Immun, 1994 Sep, 62(9), 4063 - 5 Production of Apx toxins by field strains of Actinobacillus pleuropneumoniae and Actinobacillus suis; Kamp EM et al.; The three Apx toxins of Actinobacillus pleuropneumoniae have potential value for use in vaccines and diagnostic tests which will be species specific instead of serotype specific, provided that the Apx toxins are species specific and all field strains produce these toxins . We examined 114 A . pleuropneumoniae field strains and found that they secreted either ApxI, ApxII, ApxI and ApxII, or ApxII and ApxIII and secreted no other cytolytic activities . However, proteins similar to ApxI and ApxII were also produced by Actinobacillus suis. Infect Immun, 1994 Sep, 62(9), 4043 - 6 Nitric oxide-mediated antiplasmodial activity in human and murine hepatocytes induced by gamma interferon and the parasite itself: enhancement by exogenous tetrahydrobiopterin; Mellouk S et al.; Expression of inducible nitric oxide (NO) synthase has been shown to inhibit the development of several pathogens, including fungi, bacteria, parasites, and viruses . However, there is still controversy as to whether this effector mechanism can inhibit the development of human pathogens . We now report that gamma interferon (IFN-gamma) induces the elimination of Plasmodium falciparum-infected primary human hepatocytes from cultures and that the antimalarial activity is dependent on NO . Infection with the parasite alone in the absence of added IFN-gamma caused a 10-fold increase in NO formation . Both spontaneous inhibition and IFN-gamma-induced inhibition of Plasmodium yoelii-infected murine hepatocytes were increased with the addition of the NO synthase cofactor tetrahydrobiopterin, or sepiapterin, which is converted to tetrahydrobiopterin . These results indicate that under in vitro conditions the parasite itself provides a signal that triggers induction of the NO pathway in human and murine hepatocytes and that NO formation in infected hepatocytes is limited by tetrahydrobiopterin availability. Infect Immun, 1994 Sep, 62(9), 3604 - 7 Effect of gastric pH on urease-dependent colonization of gnotobiotic piglets by Helicobacter pylori; Eaton KA et al.; Thirty-seven gnotobiotic piglets from seven litters were infected with either Helicobacter pylori N6 or urease-negative H . pylori N6ureG::Km which contains an insertion in the ureG gene and produces inactive urease . To produce achlorhydria, piglets were treated throughout the experiment with omeprazole (5 mg intravenously every 12 h) and ranitidine (75 mg orally every 6 h) . Treatment resulted in elevation of gastric pH to 7.0 +/- 1.1 throughout the experiment . Control piglets were not treated and remained normochlorhydric . Strain N6 colonized well in both normal and achlorhydric piglets . All 10 piglets were colonized, and colonization ranged from 4.4 +/- 1.5 log10 CFU/g of gastric mucosa in normochlorhydric piglets sacrificed after 2 days to 6.9 +/- 0.5 log10 CFU/g in normochlorhydric piglets sacrificed after 5 days . Strain N6ureG::Km did not colonize any of seven normochlorhydric piglets and was recovered only in low numbers (< 100 CFU/g) from four of nine achlorhydric piglets . In the second experiment, piglets were coinoculated with both strains N6 and N6ureG::Km . Coinoculation did not affect colonization by urease-positive N6 . Urease-deficient N6ureG::Km was unable to colonize even in the presence of urease-positive bacteria . These results confirm that urease enzymatic activity (and not urease protein) is essential for colonization, that this effect is independent of diffusible products of urea metabolism, and that gastric pH protection is not a major role of urease in promoting colonization by H . pylori. Cancer, 1994 Sep 1, 74(5), 1629 - 33 Chemotherapy-induced lactose intolerance in adults; Parnes HL et al.; BACKGROUND . Anorexia and weight loss contribute to the morbidity and mortality from cancer . This study was designed to test the hypothesis that chemotherapy produces lactose intolerance which could have an adverse effect on the nutritional status of patients receiving cytotoxic drugs . METHODS . Twenty-seven patients were evaluated for the development of lactose intolerance during chemotherapy . Lactose breath hydrogen testing (LBHT) was used to assess lactose malabsorption objectively . This test is based on the principle that in patients with lactase deficiency, lactose is not hydrolyzed in the small intestine and ultimately is degraded by colonic bacteria . This results in the production of hydrogen gas, which is excreted by the lungs and can be quantified with a breath hydrogen analyzer . RESULTS . Of the 27 patients studied, 8 (30%) had an abnormal postchemotherapy LBHT results, and for the population as a whole, postchemotherapy LBHT values were significantly greater than prechemotherapy values (P = 0.04) . However, only three patients (11%) showed clinical symptoms of lactose intolerance during the post-chemotherapy LBHT . Five patients had asymptomatic elevations in breath hydrogen excretion on prechemotherapy testing . One of these patients had a further increase in hydrogen excretion on Day 8 after chemotherapy, which was accompanied by symptoms of lactose intolerance . Twenty-two patients had normal prechemotherapy LBHT results . Two of these patients had abnormal post-chemotherapy LBHT results, which were associated with symptoms of lactose intolerance . CONCLUSION . Although chemotherapy may interfere with lactose metabolism, the development of symptomatic lactose intolerance is uncommon . Dietary restriction of milk products in patients receiving chemotherapy therefore is not warranted unless clinical symptoms of lactose intolerance are observed. J Anim Sci, 1994 Sep, 72(9), 2362 - 8 Effect of level of dietary neutral detergent fiber on ileal apparent digestibility and ileal nitrogen losses in pigs; Schulze H et al.; A study was conducted with 20 barrows (average BW 25 kg) to determine the effect of various levels of neutral detergent fiber (NDF) in the diet on the apparent ileal nutrient digestibility and ileal diaminopimelic acid (DAPA) content, and consequently on the amount of ileal endogenous nitrogen . The pigs were fitted with a post-valvular T-cecal cannula . They were fed .8 kg/d of a corn starch-based semisynthetic diet formulated to contain equal amounts of protein and starch and 0, 60, 120, or 180 g of purified NDF/kg of diet, included at the expense of glucose . The purified NDF (pNDF) was isolated from wheat bran using an incubation procedure with pancreatin . Ileal digestibility of NDF was approximately 17% and was independent of the pNDF level in the diet . By increasing the amount of pNDF in the diets, apparent ileal digestibilities of dry matter (DM), nitrogen (N), neutral detergent insoluble N (NDF-N), and ash decreased linearly (P < .05) . The DAPA content of the ileal digesta (g/d) was not affected by the percentage of pNDF in the diets . Calculation of the ileal bacterial N excretion indicated that more than 50% of the ileal N was of bacterial origin . With increased percentage of dietary pNDF, both endogenous and exogenous N in ileal chyme were linearly increased (P < .05) . Thus, an increase in the dietary fiber content leads to a decreased apparent ileal protein digestibility due to increased ileal losses of both endogenous and exogenous protein. Infect Control Hosp Epidemiol, 1994 Sep, 15(9), 581 - 2 Contaminated disinfectants in health clinics in Ilorin, Nigeria; Olayemi AB et al.; Five of 18 samples of working dilutions of disinfectants used in the University of Ilorin Teaching Hospital, the University Clinic, and three other urban medical centers were found to be contaminated with bacteria . The results confirmed that disinfectants in storage support the growth of infectious agents, underlining the need to use fresh preparations of disinfectants. J Emerg Med, 1994 Sep-Oct, 12(5), 645 - 9 Tissue adhesive wound repair revisited; Noordzij JP et al.; The purpose of this experimental study was to compare the effect of a tissue adhesive, N-butyl-2-cyanoacrylate, on the wound's ability to resist infection and gain strength to the effect of percutaneous polypropylene suture . Percutaneous sutures damaged host defenses, inviting the growth of bacteria to a level that was significantly greater than that encountered with the tissue adhesive . Immediately after wound closure, percutaneous sutures provided a more secure closure, as measured by breaking strength, than did tissue adhesives . Seven days later, the breaking strengths of wounds closed by tissue adhesives did not differ significantly from those repaired with percutaneous sutures . Tissue adhesive closure requires less psychomotor skills than suture closure and is accomplished more rapidly than suture closure. Bioessays, 1994 Sep, 16(9), 689 - 92 Molecular chaperones in cellular protein folding; Martin J et al.; The discovery of 'molecular chaperones' has dramatically changed our concept of cellular protein folding . Rather than folding spontaneously, most newly synthesized polypeptide chains seem to acquire their native conformation in a reaction mediated by these versatile helper proteins . Understanding the structure and function of molecular chaperones is likely to yield useful applications for medicine and biotechnology in the future. Hautarzt, 1994 Sep, 45(9), 623 - 9 {HIV-associated dermatoses and their prevalence in 456 HIV-infected patients . Relation to immune status and its importance as a diagnostic marker}; Garbe C et al.; Some 456 patients with HIV-associated skin disorders were documented in the HIV follow-up clinics at the Department of Dermatology, University Medical Center Steglitz, Berlin, during the years 1982-1992 . Males comprised 91% of the patients . The most important risk groups for HIV infection were homosexual and bisexual men (77.9%) and individuals with intravenous drug abuse (12.7%) . The most frequent dermatological diagnoses were oral candidosis (44.5%), seborrhoeic dermatitis (38.6%), folliculitis (32.9%) and Kaposi's sarcoma (23.5%) . Altogether, 138 of the patients died during the time of observation . The most frequent cause of death was disseminated Kaposi's sarcoma (26.8%) . A significant proportion of the patients developed skin diseases before significant reduction of the circulating CD4+ lymphocytes . In a still satisfactory immune situation, predominantly infections of the skin with dermatophytes (tinea), human papilloma viruses (warts) and bacteria (pyodermas) were observed . A considerable number of the HIV patients who developed zoster were also still in a favourable immune status; another 50% of these cases, however, developed the disease with reduced CD4+ lymphocyte count (< 300/microliters) . Skin manifestations that tended to occur later in the course of HIV infection were oral candidosis, oral hairy leukoplakia, herpes genitoanalis, mollusca contagiosa and Kaposi's sarcoma, in spite of their early appearance in some cases . In the large majority of these patients the immunological parameters were already clearly reduced . Fungal, bacterial and viral infections of the skin, especially with extended skin involvement, may manifest themselves during the early phases of HIV infection . The number and severity of the skin manifestations increase with progressing immunosuppression, and treatment is often a difficult challenge for the dermatologist. Nucleic Acids Res, 1994 Sep, 22(17), 3640 - 59 Effect of site-specific modification on restriction endonucleases and DNA modification methyltransferases; McClelland M et al.; Restriction endonucleases have site-specific interactions with DNA that can often be inhibited by site-specific DNA methylation and other site-specific DNA modifications . However, such inhibition cannot generally be predicted . The empirically acquired data on these effects are tabulated for over 320 restriction endonucleases . In addition, a table of known site-specific DNA modification methyltransferases and their specificities is presented along with EMBL database accession numbers for cloned genes. Nucleic Acids Res, 1994 Sep, 22(17), 3620 - 4 The translational termination signal database (TransTerm) now also includes initiation contexts; Brown CM et al.; The TransTerm database of termination codon contexts has been extended to include sense codon usage, and initiation codon contexts . The database was constructed from 23,721 coding sequences from 93 organisms . The database contains: a) the sequence around the termination codon (-10, +10); b) the sequence around the initiation codon (-20, +10); c) the length, 'G+C%' of the third position of codons (GC3), the 'codon adaptation index' (CAI) and the 'effective number of codons' statistic (Nc); d) summary tables for each organism including total codon usage, stop codon and tetranucleotide stop-signal usage, and matrices tallying base frequencies at each position around the initiation and termination codons . The data are arranged to facilitate investigation of the relationships between the three phases of protein synthesis . The database is available electronically from EMBL. FEMS Microbiol Lett, 1994 Sep 1, 121(3), 297 - 301 Identification of Renibacterium salmoninarum surface proteins by radioiodination; Fredriksen A et al.; Surface exposed proteins of Renibacterium salmoninarum were identified by radiolabelling whole bacterial cells with 125I, followed by SDS-PAGE and autoradiography . The most prominent bands had molecular masses of approximately 57 kDa and 22 kDa; in addition, some less intensively labelled bands were detected . Polyclonal sera raised against the 22 kDa protein did not react with the 57 kDa protein . N-terminal amino acid sequence analysis of the purified 22 kDa protein showed no similarity with the sequence of the 57 kDa protein. Carcinogenesis, 1994 Sep, 15(9), 1895 - 902 The role of two conserved amino acids, glutamine 90 and asparagine 137, in O6-methylguanine-DNA methyltransferase stability, activity and substrate specificity; Pieper RO et al.; To assess the possibility that two conserved amino acids (glutamine 90 and asparagine 137) in O6-methylguanine-DNA methyltransferase (MGMT) are involved in protein-substrate contact and/or discrimination between favored and non-favored substrates, families of proteins mutant at these two sites were expressed in alkyltransferase-deficient bacteria and analyzed for stability, ability to repair O6-methylguanine (MG)-containing DNA, and ability to differentially repair a preferred (MG-containing DNA) versus a non-preferred (free base MG) substrate . All seven proteins mutant at glutamine 90 (except a proline mutant) were stable in bacteria and repaired MG-containing DNA (> 50% of wild-type levels) . A representative glutamine 90 mutant protein was not, however, significantly different from the wild-type protein in the preferential repair of MG-containing DNA versus MG free base . Of eight proteins mutant at asparagine 137, only glutamine and serine mutants repaired MG-containing DNA to any degree (8.5% and 0.8% of wild-type respectively) and only the glutamine mutant protein was detectable in bacterial sonicates by Western blot analysis . Alanine and leucine mutant alkyltransferases, inactive and unstable as non-fusion proteins, could, however, be stably expressed in bacteria as glutathione S-transferase fusion proteins, although the proteins were still inactive in repair . These results suggest that while glutamine 90 has no direct role in MG-DNA methyltransferase-mediated repair or free base/lesioned DNA substrate specificity, asparagine 137 is important in both the stability and activity of the protein and may contribute to the formation or function of the active site of the protein. Clin Exp Immunol, 1994 Sep, 97(3), 386 - 91 Primary T lymphocyte immunodeficiency associated with a selective impairment of CD2, CD3, CD43 (but not CD28)-mediated signal transduction; Rodriguez-Gallego C et al.; A 2-year-old female with important signs of immune response failure against virus, bacteria, fungi and protozoa and no obvious humoral or lymphocyte phenotypical defect was studied . Both peripheral blood mononuclear cells and IL-2-dependent T cell lines derived from the patient showed a severe selective T cell activation impairment via CD2, CD3 and CD43; however, this defect was reversible with the addition of either IL-2, or phorbol myristate acetate (PMA) or anti-CD28 antibodies . Concordantly, the induction of IL-2 (and, in part, IL-3 and IL-4) messenger RNA was severely reduced in stimulated T cells, but that of other cytokines was either normal (IL-5) or only slightly diminished (interferon-gamma (IFN-gamma)) . It is concluded that an activation T cell defect exists previous to protein kinase C (PKC) and between membrane receptors and the activation pathway of certain response genes encoding for interleukins involved in proliferation (i.e . IL-2, IL-3 and IL-4), but not of others (i.e . IL-5) . The use of T cell lines from human T lymphocyte activation deficiencies allows dissection of T cell pathology and the corresponding physiological pathways . In the present description, there is an evident independence of the CD28 T cell activation pathway from those induced through CD2 or CD3, and the differential gene regulation of the different interleukins. Prev Med, 1994 Sep, 23(5), 704 - 8 Prevention of periodontal diseases in adults: strategies for the future; Jeffcoat MK; Gingivitis and periodontitis are the most prevalent periodontal diseases in adults . Gingivitis is characterized by inflammation of the gingiva without loss of connective tissue attachment to the teeth while periodontitis results in loss of attachment and alveolar bone and may lead to tooth loss . Gingivitis is highly prevalent in adults in the United States, and up to 70% of adults have at least mild periodontitis . In only a small proportion of adults (< 15%) does periodontitis progress to severe disease . The etiology of periodontal disease is infection with pathogenic dental plaque bacteria in a susceptible host . Strategies for preventing periodontal diseases therefore may intervene at the level of the initiation of the inflammatory process, or by preventing the progression of bone and attachment loss in periodontitis . Improved mechanical and chemical plaque control as well as improved restorative materials to facilitate plaque removal continue to enhance the patient's ability to control the plaque bacteria . Strategies to target prevention to the patients who need it most include risk factor assessment, new diagnostic methods, and further elucidation of the natural history of periodontal disease . Further study of the etiology and pathophysiology of periodontitis will aid in the prevention of further destruction through targeted use of local and systemic antibiotics and well as drugs to aid in the host response . Ultimately research may yield multivalent vaccines to be used in high-risk patients. Mol Endocrinol, 1994 Sep, 8(9), 1245 - 52 A chimeric thyroid hormone receptor constitutively bound to DNA requires retinoid X receptor for hormone-dependent transcriptional activation in yeast; Lee JW et al.; T3 receptors (TRs) regulate transcription by binding to specific DNA response elements as heterodimers with the retinoid X receptors (RXRs) . To study the consequences of this heterodimerization for transcriptional regulation in the absence of complications associated with its effects on DNA binding affinity, we expressed in the yeast Saccharomyces cerevisiae a chimeric protein consisting of the rat TR beta 1 ligand-binding domain fused to the DNA-binding domain of the bacterial repressor lexA (lexATR) . LexATR is a weak, T3-responsive activator of a beta-galactosidase reporter gene controlled by upstream lexA-binding sites (lexA-beta-gal) . In contrast, coexpression of human RXR alpha (hRXR alpha) strongly enhances both the basal and ligand-induced transcriptional activities . Both the N-terminal activation domain of RXR and sequences at the extreme C terminus of lexATR are required for this T3- and RXR-dependent transcriptional activation . The lexATR chimera was also used to characterize receptor-receptor interactions using the two-hybrid system . Coexpression of B42RXR, a fusion protein of the human RXR alpha ligand-binding domain and the B42 transcriptional activation domain, strongly increases the transcriptional activity of lexATR in the absence of T3 or 9-cis-retinoic acid . We conclude that RXR is essential for full, T3-dependent transcriptional activity of the TR in yeast, and that protein-protein interaction of TR and RXR in vivo is ligand-independent. Semin Respir Infect, 1994 Sep, 9(3), 153 - 65 An overview of community acquired pneumonia with lessons learned from the British Thoracic Society Study; Macfarlane J; There are many factors resulting in a changing pattern of pneumonia . This varies from the impact of an aging population, patients surviving longer with underlying chronic disease, severe illness, and various causes of immunosuppression and the effect of new investigations, new antibiotics, and the recognition of new pathogens . Numerous studies have been performed over the last few years regarding the cause and outcome of community-acquired pneumonia (CAP) . Marked variation in results has been seen related to the criteria used for defining and diagnosing pneumonia, the population studied, and the use of differing investigations and diagnostic criteria . This is particularly apparent when comparing the different incidence of pneumococcal infection as a cause of CAP in studies from different parts of the world . Extrapolation of the findings from the multicenter British Thoracic Society (BTS) study of pneumonia suggests that pneumococcal infection is more common than several studies suggest . Having said that, it is clear from examination of the many studies that CAP is a diverse disease and that different part of the world will have to develop individual management strategies based on a critical analysis of the best available study data appropriate to their local or national situation. J Gastroenterol Hepatol, 1994 Sep-Oct, 9(5), 501 - 6 Prevalence of Helicobacter pylori in southern Indian controls and patients with gastroduodenal disease; Prasad S et al.; The spiral organism Helicobacter pylori has been causally implicated in the genesis of various gastroduodenal diseases . Since these diseases are common in southern India, this study was undertaken to determine the prevalence of H . pylori in the gastric mucosa of asymptomatic adults and patients with various gastroduodenal diseases . H . pylori was detected in the gastric mucosa of 25 of 30 (83.3%) normal volunteers . Prevalence rates in the disease groups were also high, and included 38 of 41 patients with duodenal ulcer (92.6%), 13/16 with gastric ulcer (81.3%), and 85/119 subjects (71.4%) with non-ulcer dyspepsia . Light microscopic examination of the gastric mucosa provided the best method of detecting H . pylori . H . pylori colonization was significantly associated with histological abnormalities, mainly chronic atrophic gastritis (147) and superficial gastritis (11), while only three of 161 H . pylori positive patients had histologically normal antral mucosa . Ultrastructural examination revealed changes in the apical complex of the gastric mucosal cells in response to bacterial adhesion, with mucus depletion and cellular damage . Bacteria were also noted disrupting the tight junctions and entering the intercellular spaces . The high prevalence of H . pylori infection may explain the high incidence of gastritis, duodenal ulceration and gastric carcinoma in this population . However, in this population, the prevalence of infection in asymptomatic individuals was nearly as high as that in duodenal ulcer, underlining the need for further study to identify the differences in host response or bacterial pathogenicity that lead to the development of ulcer in only some individuals. Am J Forensic Med Pathol, 1994 Sep, 15(3), 231 - 5 Postmortem redistribution and degradation of dothiepin . Human case studies and an animal model; Pounder DJ et al.; Two suicides took estimated maximum dothiepin doses of 765 and 1875 mg, respectively . Initial drug levels in nine and 12 blood samples were 0.26-1.85 and 4.08-23.98 mg/L, with highest concentrations in the pulmonary veins . Pulmonary artery concentrations rose markedly over 18 h: 0.32 rising to 0.9, and 6.54 rising to 19.53 mg/L . Peripheral blood concentrations were relatively stable . Concentrations in liver, heart, lung, and skeletal muscle were, for case 1, 4.3, 2.92, 18.6, and 1.1 mg/kg; and, for case 2, 52, 16.8, 73.9, and 8.98 mg/kg . New Zealand white female rabbits (2.4-3.2 kg) given 20 mg dothiepin hydrochloride intravenously were killed with pentobarbital after 1 h . Blood was sampled from the thorax, infra-renal inferior vena cava, and supra-renal inferior vena cava at 0, 1/2, 1, 4, 8, 12, and 24 h postmortem in paired animals . Liver, heart, lung, and skeletal muscle were sampled at 0 and 24 h . Mean dothiepin levels in thoracic blood rose from 0.43 mg/L at time 0 to 1.73 at 8 h and then fell to 0.61 at 12 h, likely reflecting initial redistribution from the lungs (63.4 mg/kg at time 0 and 27.3 mg/kg at 24 h) followed by putrefaction-associated bacterial degradation . Falls in blood drug levels associated with putrefaction were not seen in the human cases . Interpretation of postmortem dothiepin blood concentrations is complicated by pronounced interindividual variations in in vivo pharmacokinetics, the postmortem redistribution phenomenon, and variable drug degradation by bacteria. Proteins, 1994 Sep, 20(1), 34 - 51 Pyrrolidone carboxyl peptidase (Pcp): an enzyme that removes pyroglutamic acid (pGlu) from pGlu-peptides and pGlu-proteins; Awade AC et al.; Pyrrolidone carboxyl peptidase (EC 3.4.11.8) is an exopeptidase commonly called PYRase, which hydrolytically removes the pGlu-proteins . pGlu also known as pyrrolidone carboxylic acid may occur naturally by an enzymatic procedure or may occur as an artifact in proteins or peptides . The enzymatic synthesis of pGlu suggests that this residue may have important biological and physiological functions . Several studies are consistent with this supposition . PYRase has been found in a variety of bacteria, and in plant, animal, and human tissues . For over two decades, biochemical and enzymatic properties of PYRase have been investigated . At least two classes of PYRase have been characterized . The first one includes the bacterial and animal type I PYRases and the second one the animal type II and serum PYRases . Enzymes from these two classes present differences in their molecular weight and in their enzymatic properties . Recently, the genes of PYRases from four bacteria have been cloned and characterized, allowing the study of the primary structure of these enzymes, and their over-expression in heterelogous organisms . Comparison of the primary structure of these enzymes revealed striking homologies . Type I PYRases and bacterial PYRases are generally soluble enzymes, whereas type II PYRases are membrane-bound enzymes . PYRase II appears to play as important a physiological role as other neuropeptide degrading enzymes . However, the role of type I and bacterial PYRases remains unclear . The primary application of PYRase has been its utilization for some protein or peptide sequencing . Development of chromogenic substrates for this enzyme has allowed its use in bacterial diagnosis. Biotechniques, 1994 Sep, 17(3), 484 - 6, 488, 490 Application of cycle dideoxy fingerprinting to screening heterogeneous populations of the equine infectious anemia virus; Langemeier JL et al.; Nucleotide sequence heterogeneity in a population of the equine infectious anemia virus (EIAV) was investigated using a modification of the dideoxy fingerprinting (ddF) technique . PCR-amplified regions of the gag gene from EIAV isolates were ligated into plasmid vectors and used to transform bacteria . The single dideoxynucleotide sequencing step was performed using plasmid DNA prepared from individual bacterial colonies using an 35S end-labeled primer and Taq DNA polymerase . Analysis of the products of this reaction was conducted using non-denaturing polyacrylamide gel electrophoresis . Polymorphism within this gene was suggested by the presence of several distinct electrophoretic profiles . Significantly, each profile could be correlated with variations in nucleotide sequence, which demonstrates that cycle ddF (CddF) offers a rapid and sensitive approach to identify polymorphism in PCR-amplified products. Vet Clin North Am Small Anim Pract, 1994 Sep, 24(5), 921 - 52 Management of otitis externa; Rosychuk RA; Otitis externa represents one of the most common reasons that pets are presented for veterinary attention . They are also some of the more frustrating entities practitioners are called on to deal with . Successful management depends on an understanding of the primary, predisposing, and perpetuating factors involved in the pathogenesis of otitis externa . Emphasis is then placed on establishing a diagnosis through physical examination, cytologic examination, culture and sensitivity testing, radiographs and biopsies . The general goals of management are to resolve, remove, or control primary factors, clean and dry the ear, reduce inflammation and resolve secondary infections . These goals are achieved through various cleaning techniques, topical, and systemic therapies . Therapeutic alternatives are given for otitis involving bacteria, Malassezia, otodectes, demodex, allergies, ceruminous disorders, the idiopathic inflammatory/hyperplastic otitis externa of cocker spaniels, "Swimmer's Ear", contact/irritant reactions, overtreatment, and concurrent otitis media. Infect Dis Clin North Am, 1994 Sep, 8(3), 617 - 35 Dermatologic manifestations of nosocomial infections; Valainis GT; There is no substitute for preventing dermatologic infection in a hospitalized patient by maintaining intact, well nourished skin . The integrity of the integument becomes assaulted on a daily basis from a variety of methods . Measures to lessen this risk can be undertaken, but it may not be totally preventable . The phenomenon of infected desquamated squamous cells being dispersed into the environment by patients and health care workers is one that deserves further study . If this proves to be an important factor, hospital spread of bacteria may indeed be unavoidable . It is hoped that this review will serve as a starting point in an area short on clinical data . Further study into this arena is clearly needed. Clin Infect Dis, 1994 Sep, 19(3), 402 - 8 Brain abscess following marrow transplantation: experience at the Fred Hutchinson Cancer Research Center, 1984-1992; Hagensee ME et al.; The etiology of brain abscess in patients undergoing marrow transplantation at the Fred Hutchinson Cancer Research Center in Seattle was assessed in a retrospective review . Fifty-eight patients with histology- or culture-proven brain abscess diagnosed between January 1984 and March 1992 were identified . A fungus was isolated in 92% of cases . Aspergillus species were the most prevalent fungi (58% of cases), and Candida species were second in frequency (33%); sporadic cases were caused by Rhizopus, Absidia, Scopulariopsis, and Pseudallescheria species . Bacteria were involved in fewer than 10% of cases . There was no appreciable variation from year to year in the incidence of brain abscess over this period . Aspergillus brain abscess was associated with concomitant pulmonary disease (87% of cases), whereas candida brain abscess often occurred in association with fungemia (63% of cases) or neutropenia (63%) . Mortality was high (97%); the risk of death was unrelated to etiology or therapeutic regimen . Since the etiology of brain abscess in patients undergoing marrow transplantation is primarily fungal, the development of better antifungal therapeutic and/or prophylactic modalities is warranted. Biologicals, 1994 Sep, 22(3), 233 - 42 Development of pertussis serological potency test . Serological assessment of antibody response induced by whole cell vaccine as an alternative to mouse protection in an intracerebral challenge model; van der Ark A et al.; The current potency test for pertussis vaccines, the mouse protection test (MPT), has many disadvantages . However, no alternative is yet available . The purpose of this study is to develop a serological alternative for the MPT based on in vitro assessment of the humoral immune response against pertussis in mice . After immunization with pertussis whole cell vaccine, the MPT shows a normal primary and secondary antibody response . Moreover, the i.c . challenge has a distinct booster effect on the pertussis IgG response . The relationship between the concentration of IgG antibodies against the surface-antigens of pertussis bacteria and the survival of mice after the i.c . challenge was demonstrated in a modified MPT (R = 0.91) . To this end a protecting antibody level of > or = 45 EU/ml was selected as a level at which concentration most of the mice survived . Survival of mice in the MPT could be predicted, based on the antibody concentration at the day of challenge . Potencies estimated with the predicted and actual survival corresponded well (P = 0.990) . This confirmed the essential role of vaccine induced pertussis antibodies in the protection against a lethal i.c . challenge and offered a possibility to develop a pertussis potency test based on serology . We developed a model in which mice (20-24 g) are immunized (i.p.) with graded doses of vaccine and bled after four weeks . Sera are titrated in Bordetella pertussis whole cell ELISA and potency based on vaccine dose dependent antibody response is estimated by means of a parallel line analysis . The potency of vaccines tested in the Pertussis Serological Potency Test (PSPT) and MPT are significantly similar, a P-value of 0.92 was found by means of the chi 2 test . Compared to the MPT, the PSPT is more reproducible as is indicated by its smaller 95% confidence intervals . Moreover, by using the PSPT the animal distress can be reduced to an acceptable level and the PSPT also results in a reduction of more than 25% in use of mice. Trends Biotechnol, 1994 Sep, 12(9), 379 - 86 The cellulosome--a treasure-trove for biotechnology; Bayer EA et al.; The cellulases of many cellulolytic bacteria are organized into discrete multienzyme complexes, called cellulosomes . The multiple subunits of cellulosomes are composed of numerous functional domains, which interact with each other and with the cellulosic substrate . One of these subunits comprises a distinctive new class of noncatalytic scaffolding polypeptide, which selectively integrates the various cellulase and xylanase subunits into the cohesive complex . Intelligent application of cellulosome hybrids and chimeric constructs of cellulosomal domains should enable better use of cellulosic biomass and may offer a wide range of novel applications in research, medicine and industry. Mycoses, 1994 Sep-Oct, 37(9-10), 329 - 35 Pulmonary fungal infections in immunocompromised patients: incidence and risk factors; von Eiff M et al.; In a prospective study, 178 patients with fever > 38.4 degrees C and newly diagnosed pulmonary infiltrates underwent bronchoscopy with bronchoalveolar lavage (BAL), aspiration of bronchial secretions (BS) and, in 71 cases, protected specimen brushing (PSB) . In 42/143 immunocompromised patients (haematological malignancies, n = 92; AIDS, n = 22; immunosuppressant therapy, n = 29) and in 4/35 patients with no defined underlying disease fungal pneumonia was present (candidosis, n = 35; aspergillosis, n = 8 mixed fungal infection, n = 3) . Candidosis was combined, in 17 cases, with Aspergillus (n = 3), bacterial (n = 15) or cytomegalovirus (n = 2) infection . Aspergillosis was combined in eight cases with infection with Candida (n = 3), Pneumocystis carinii (n = 1) or bacteria (n = 5) . The sensitivity of BAL and PSB in Candida pneumonia was 48% and 50%, respectively; specificity was 75% and 74% respectively . Bronchial secretions were more sensitive in detecting Candida pneumonia, but specificity was only 55% . In aspergillosis, the specificity of BAL, BS and PSB in each case was 100%; the sensitivity of BAL, BS and PSB was 38%, 64% and 100% . Twenty-four fungal infections were fatal . Unfavourable prognostic factors were respiratory failure needing mechanical ventilation, diffuse bilateral pulmonary infiltrates, mixed fungal infections and start of i.v . antifungal treatment > 14 days after fever onset, which were associated with a mortality rate of 74%, 67%, 67% and 63% respectively. Lik Sprava, 1994 Sep-Dec, (9-12), 100 - 2 {Functional disorders of the blood neutrophils and their correction in patients with bronchiectasis and lung abscess}; Kazimirko VK; Studies conducted in 25 patients with bronchiectatic disease, 40 with chronic lung abscess, revealed decrement of the blood neutrophil capacity for uptaking bacteria, and cytochemical changes in these . Expediency of inclusion into the combination therapy of those drugs intensifying the leucocyte energy metabolism and phagocytic activity (vitamins C, B1, B2, B6, B12, PP, glutamic acid, prodigiosane, polyglucine) was validated in the experiment. J Biochem (Tokyo), 1994 Sep, 116(3), 575 - 81 Cloning and functional expression of human inducible nitric oxide synthase (NOS) cDNA from a glioblastoma cell line A-172; Hokari A et al.; Nitric oxide (NO) is a messenger molecule with diverse functions throughout the body . The inducible type of nitric oxide synthase (NOS) is considered to be a key molecule in the immune responses to bacteria, parasites, and tumors, and its gene expression is regulated by cytokines . We isolated 3 overlapping partial inducible NOS cDNA clones from a human glioblastoma cell line A-172 induced by IL-1, TNF-alpha, and IFN-gamma . The 3,963-bp human glioblastoma inducible NOS cDNA contained the longest open reading frame of 3,459 bp, which encoded a polypeptide of 1,153 amino acids with a calculated molecular mass of 131 kDa . This human inducible NOS possessed consensus recognition sites for the cofactors FMN, FAD, and NADPH and calmodulin recognition sites, and displayed 48.1% sequence identity with the endothelial type, 43.1% with the neuronal type, and 99.3% with the inducible type from hepatocytes, and 99.9% with the inducible type from chondrocytes and adenocarcinoma . An expression plasmid consisting of pSG5 expression vector and cDNA containing the entire putative coding sequence was constructed and transfected into COS-1 cells . COS-1 cells showed nitric oxide synthase activity together with a 130 kDa immunoreactive band on Western blot analysis. Nucleic Acids Res, 1994 Sep, 22(17), 3502 - 7 Collection of small subunit (16S- and 16S-like) ribosomal RNA structures: 1994; Gutell RR; A collection of diverse 16S and 16S-like rRNA secondary structure diagrams are available . This set of rRNAs contains representative structures from all of the major phylogenetic groupings--Archaea, (eu)Bacteria, and the nucleus, mitochondrion, and chloroplast of Eucarya . Within this broad phylogenetic sampling are examples of the major forms of structural diversity currently known for this class of rRNAs . These structure diagrams are available online through our computer-network WWW server and anonymous ftp, as well as from the author in hardcopy format. Proc Natl Acad Sci U S A, 1994 Aug 30, 91(18), 8562 - 6 Divergent T-cell cytokine patterns in inflammatory arthritis; Simon AK et al.; A major immunoregulatory mechanism in inflammatory infections and allergic diseases is the control of the balance of cytokines secreted by Th1/Th2 subsets of T helper (Th) cells . This might also be true in autoimmune diseases; a Th2 pattern that prevents an effective immune response in infections with intracellular bacteria may favor immunosuppression in autoimmune disease . The pattern of cytokine expression was compared in the synovial tissue from patients with a typical autoimmune disease, rheumatoid arthritis, and with a disorder with similar synovial pathology but driven by persisting exogenous antigen, reactive arthritis . We screened 12 rheumatoid and 9 reactive arthritis synovial tissues by PCR and in situ hybridization for their expression of T-cell cytokines . The cytokine pattern differs significantly between the two diseases; rheumatoid arthritis samples express a Th1-like pattern whereas in reactive arthritis interferon gamma expression is accompanied by that of interleukin 4 . Studying the expression of cytokines by in situ hybridization confirmed the results found by PCR; they also show an extremely low frequency of cytokine-transcribing cells . In a double-staining experiment, it was demonstrated that interleukin 4 is made by CD4 cells . These experiments favor the possibility of therapeutic intervention in inflammatory rheumatic disease by means of inhibitory cytokines. Schweiz Med Wochenschr, 1994 Aug 27, 124(34), 1479 - 88 {Infectious complications in cardiac transplantation: Lausanne experience}; Menafoglio A et al.; Infectious complications, a major cause of morbidity and mortality after heart transplantation, were reviewed in 49 heart transplant patients at Lausanne . The follow-up lasted 32 months on average . 43 patients (88%) presented 108 infections (2.20 episodes of infection/patient) . 38 severe infections (0.78 episodes/patient) were diagnosed in 27 patients (55%) . 2 of the 9 deaths which occurred were due to infection . The viruses, principally of the herpes group, were responsible for 37% of all the infections, and bacteria for 28% . About a third of the viral and bacterial infections were severe . The other documented infections were caused by fungi (13%), which were most often responsible for superficial infections, and rarely by protozoa (5%) . Finally, in 17% of infectious episodes, the pathogen could not be identified . Cytomegalovirus was the pathogen the most frequently responsible in severe infections . The highest incidence of infections occurred during the first 2-3 months after transplantation and was reduced considerably after the 6th month . The distribution of different pathogens was related to specific periods after the transplant . Our results confirm that infection is a major complication of heart transplantation . Clinical and prophylactic aspects of some infections are reviewed. Gene, 1994 Aug 19, 146(1), 123 - 7 Codon usage adaptation in the ferredoxin-NADP+ oxidoreductase of Cyanophora paradoxa upon translocation from cyanoplast to nucleus; Luttke A et al.; Previous investigations of the petH gene of the biflagellated autotrophic protist Cyanophora paradoxa (Cp; Glaucocystophyta), descendant of an original endocyanome (symbiotic consortium of a eukaryote with an endocytobiotic cyanobacterium), established that: (i) the gene coding for a cyanoplast protein (FNR) is located on the nuclear genome; (ii) the sequence of the mature protein shows a high degree of amino-acid conservation to cyanobacterial homologs; (iii) the sequence of the transit peptide of the pre-protein displays poor, if any, homology to counterparts in higher plants . Here, we show that the G+C content and codon usage of this gene are most similar to a genuine nuclear gene . By contrast, the G+C content and codon usage display substantial differences to a collection of 30 cyanoplast encoded genes mainly attributable to alterations in the third codon position . Correspondence analysis on codon preference parameters corroborates the claim of codon usage adaptation of the translocated gene to the nuclear pattern . As a consequence, codon usage distances of genes of Cp encoded either by the nucleus or the cyanoplasts vs . homologous genes of the cyanobacterium, Anabaena, are notably different; this result has important phylogenetic implications. Mol Cell Biochem, 1994 Aug 17, 137(1), 39 - 55 Structure, biosynthesis, and function of salivary mucins; Wu AM et al.; The glandular secretions of the oral cavity lining the underlying buccal mucosa are highly specialized fluids which provide lubrication, prevent mechanical damage, protect efficiently against viral and bacterial infections, and promote the clearance of external pollutants . This mucus blanket contains large glycoproteins termed mucins which contribute greatly to the viscoelastic nature of saliva and affect its complex physiological activity . The protein core of mucins consists of repetitive sequences, rich in O-glycosylated serine and threonine, and containing many helix-breaking proline residues . These features account for the extended, somewhat rigid structure of the molecule, a high hydrodynamic volume, its high buoyant density, and high viscosity . The oligosaccharide moiety of salivary mucins accounts for up to 85% of their weight . The oligosaccharide side chains exhibit an astonishing structural diversity . The isolation, composition, structure, molecular characteristics, and functional relevance of salivary mucins and their constituents is discussed in relation to recent advancements in biochemistry and molecular biology. Biochemistry, 1994 Aug 16, 33(32), 9741 - 52 Photosynthetic deficiency of a pufX deletion mutant of Rhodobacter sphaeroides is suppressed by point mutations in the light-harvesting complex genes pufB or pufA; Barz WP et al.; The pufX gene of the facultative phototroph Rhodobacter sphaeroides encodes a membrane protein that is required for photoheterotrophic growth . Deletion of pufX impairs the photosynthetic generation of a transmembrane potential, suggesting a role for the PufX protein in light-driven cyclic electron transfer {Farchaus, J . W., et al . (1992) EMBO J . 11, 2779-2788} . Here we describe the isolation and characterization of 65 spontaneous suppressor mutants in which photosynthetic competence was restored by secondary mutations . Genetic analysis revealed the occurrence of single point mutations altering highly conserved residues within the light-harvesting complex, B875 . One of three tryptophan codons was changed to stop or arginine codons in 89% of these suppressor mutants . Spectral characterization and Western blot analysis were used to examine the B875 assembly and the stable expression of the altered light-harvesting polypeptides . Three different groups of suppressor mutants were found: (1) No stable expression of altered B875 polypeptides was detected for the alpha 43W-->* and beta 44W-->* mutants . (2) There was expression of the mutated B875-beta chain, but no stable B875 assembly in the beta 47W-->R mutants . (3) Intact B875 complexes were found for the alpha 47S-->F or beta 20H-->R mutants . These results provide evidence that the differently altered B875 polypeptides do not substitute directly for the PufX protein but lead to structural rearrangements in the macromolecular membrane organization, thus restoring a sufficiently high capacity for light-driven cyclic electron transfer. Proc Natl Acad Sci U S A, 1994 Aug 16, 91(17), 8190 - 4 Hypothesis: disseminated intravascular inflammation as the inflammatory counterpart to disseminated intravascular coagulation; Bull BS et al.; We have identified a leukocyte activation syndrome that is occasionally associated with the transfusion of intraoperatively recovered erythrocytes . This syndrome appears to result from intravascular damage caused by leukocytes activated during the erythrocyte salvage process . We hypothesize that this syndrome is part of a larger disease grouping: disseminated intravascular inflammation (DII) . DII is the analog of the coagulation disorder disseminated intravascular coagulation . In disseminated intravascular coagulation, the organ damage results from uncontrolled activation of the clotting pathway; in DII the damage is caused by leukocytes that have become activated by direct contact with bacteria or in rare instances--such as erythrocyte salvage--in the absence of bacteria and bacterial products . Recent studies of the hazards associated with intraoperative blood salvage indicate that activation of leukocytes can be achieved by exposure to activated platelets alone . If such activated leukocytes are reinfused along with the washed erythrocytes, widespread organ damage may result . The lung is the organ most severely affected by activated leukocytes . Adult respiratory distress syndrome is one outcome . It is likely that DII is a presently unrecognized pathophysiological process that complicates a variety of primary disease states and increases their lethality. FEBS Lett, 1994 Aug 15, 350(1), 24 - 8 The electronic structure of P840+ . The primary donor of the Chlorobium limicola f . sp . thiosulphatophilum photosynthetic reaction centre; Rigby SE et al.; The radical cation P840+ . was studied in frozen suspensions of Chlorobium limicola f . sp . thiosulphatophilum membranes using ENDOR and Special TRIPLE spectroscopies . The spectra show that P840+ . arises from a bacteriochlorophyll a 'special' pair with a highly symmetrical distribution of electron spin density between the constituent bacteriochlorophylls . Special TRIPLE spectroscopy has resolved the separate contributions of the two halves of the pair and revealed small deviations from a 1:1 electron spin density distribution . Nevertheless P840+ . appears to come the closest yet to the symmetrical 'dimer' originally proposed for the structure of the primary donor radical cation (P870+.) in purple non-sulphur photosynthetic bacteria. J Healthc Mater Manage . 1994 Sep;12(9):28, 30, 32. Mattress evaluation for long-term care facilities; Stank C et al.; Patients spend more than a third of their hospital time in bed and considerably more than that if they are residents in a long-term care facility . When our facility, Fair Acres Geriatric Center, a 911-bed long-term care facility in Lima, PA, noticed increasing losses of our standard mattresses, we decided to evaluate new products . We listed very important criteria (bacteria resistance, flame retardation, self-deodorization and comfort and resiliency) and important criteria (stain resistance, cost and warranty) and then brought in three standard mattresses for our staff to evaluate . We were able to procure a mattress that met our criteria and halved our costs in the process. J Biol Chem, 1994 Aug 5, 269(31), 19826 - 9 Identification of a putative metal binding site in a new family of metalloregulatory proteins; Shi W et al.; The transcription of the ars operon is negatively controlled by the ArsR repressor and induced by arsenite and antimonite . Using hydroxylamine mutagenesis, four arsR mutants were isolated; three were selected for inability to respond to inducers: C32Y, C32F, and C34Y . Each of the three altered proteins still bound specifically to the ars operator, but inducers were less effective in effecting the release of the altered proteins from the DNA . Each of the mutant arsR genes in trans with a reporter gene controlled by the ars promoter repressed expression of the reporter gene, and addition of inducer did not relieve repression . These results suggest that the altered ArsR proteins are defective in the inducer binding site . The fourth arsR mutation, resulting in a H50Y alteration, produced constitutive expression . His-50 is located within a putative helix-turn-helix region of the ArsR protein . We propose that cysteines Cys-32 and Cys-34 in the ArsR protein comprise part of a metal binding motif found in members of the ArsR family of metalloregulatory proteins. Proc Natl Acad Sci U S A, 1994 Aug 2, 91(16), 7653 - 7 Vaccinia protein kinase 2: a second essential serine/threonine protein kinase encoded by vaccinia virus; Lin S et al.; The major protein kinase activity from vaccinia virus core particles was purified to near homogeneity . The protein kinase is a 50-kDa polypeptide that is shown here to phosphorylate primarily seryl residues in alpha-casein, a casein kinase I-specific peptide substrate, and itself through autophosphorylation . The sequence of four peptides derived from the protein kinase demonstrated that it is encoded by the vaccinia virus F10L gene . Expression of the F10L gene product in bacteria as a fusion with glutathione S-transferase confirmed that the vaccinia F10L gene encodes the protein kinase . We have termed this enzyme vaccinia protein kinase 2 (VPK2) to distinguish it from the protein kinase encoded by the vaccinia B1R gene . Targeted disruption of the VPK2 gene with a positive selectable marker demonstrated that all viruses with a disrupted gene also possessed a wild-type gene, suggesting that VPK2 is essential for viability . The discovery of a second essential protein kinase encoded by vaccinia virus, in addition to a protein phosphatase, underscores the importance of protein phosphorylation in poxvirus biogenesis. Biochim Biophys Acta, 1994 Aug 2, 1218(3), 478 - 80 Identification and cloning of human chaperonin 10 homologue; Monzini N et al.; We have identified a heat-shock-inducible 10 kDa protein in the human hepatoma cell line HepG2 . The total RNA extracted from the heat-shocked cells was amplified by reverse transcription PCR (polymerase chain reaction) using 21 5' and 18 3' oligonucleotides of rat cpn10 (chaperonin10) cDNA as primers . Sequencing of the above PCR fragment showed a very high homology between human, bovine and rat cpn10 cDNA . The predicted amino acid sequence revealed a 100% identity with the bovine homologue. Biochim Biophys Acta, 1994 Aug 2, 1218(3), 273 - 82 Cloning and characterization of the SmIMP25 integral membrane protein of the parasitic helminth Schistosoma mansoni; Markovics A et al.; The cDNA and genomic clones encoding a 25 kDa integral membrane protein, termed SmIMP25, were isolated from Schistosoma mansoni . The 2.2 kb SmIMP25 mRNA was found in all developmental stages of the parasite tested: miracidium, sporocyst, cercaria and adult worm . The SmIMP25 gene is at least 16 kb long and it is split by four introns ranging in size from 36 bp to > or = 9 kb . Excluding the introns, the gene and the cDNA show 100% sequence identity . The cDNA has an open reading frame encoding a protein 223 amino acids long . The predicted sequence reveals a distinct hydrophobic domain of 20 amino acids located 12 residues from the carboxyl-terminal end . The properties of this domain (marked hydrophobicity, size, flanking by charged residues and C-terminal location) are typical of the transmembrane segments of integral membrane proteins . The presence of three potential N-glycosylation sites is also consistent with membrane proteins that are often glycosylated at the extracellular domain . Accordingly we propose that SmIMP25 is an integral membrane protein in which residues 1-191 are extracellular, residues 192-211 comprise the hydrophobic domain that spans the membrane, and residues 212-223 are intracellular . The SmIMP25 was synthesized as a fusion protein in bacteria and antibodies were elicited in rabbits . Antibodies against SmIMP25 specifically precipitated a 25 kDa protein from cell-free products programmed by schistosome mRNA, in agreement with the size of the protein predicted from the cDNA sequence . Immunofluorescence studies showed SmIMP25 on the surface of the parasite . Surface molecules expressed at the host-parasite interface are likely to provide information on host parasite relationship and may serve as targets for protective immunity. Nippon Shokakibyo Gakkai Zasshi, 1994 Aug, 91(8), 1277 - 82 {Evaluation of polymerase chain reaction for diagnosis of Helicobacter pylori infection}; Takagi A et al.; To evaluate diagnostic tests of Helicobacter pylori (H . pylori), we compared polymerase chain reaction (PCR) for the specific detection of H . pylori, culture and positivity of serum antibody against the bacteria in 59 patients with gastroduodenal disease . PCR assay was designed to amplify 203bp of DNA fragments . PCR detected 10pg of H . pylori DNA, or 40 CFU of the bacteria . PCR was positive in 82.1% of histological gastritis with neutrophil infiltration . Culture and serum antibody to H . pylori were positive in 65.0%, and 94.1% of those patients . Detection rate by PCR was significantly higher than that by the culture methods in patients with chronic gastritis . These results demonstrate that PCR is a sensitive diagnostic test for H . pylori infection. FEMS Microbiol Lett, 1994 Aug 1, 121(1), 61 - 9 Purification and characterization of two new c-type cytochromes involved in Fe2+ oxidation from Thiobacillus ferrooxidans; Valkova-Valchanova MB et al.; Two new c-type cytochromes have been purified from cell membranes of the acidophilic Thiobacillus ferrooxidans . In contrast to a soluble cytochrome c with molecular mass of 14 kDa reported earlier, a membrane-bound cytochrome c with a mass of 21 kDa was solubilized with octylthioglucoside and purified to homogeneity . In addition, a high molecular mass c-type cytochrome (68 kDa) was also solubilized and purified using Triton X-100 as a detergent . Both acid-stable species are partially released during osmotic shock and chloroform treatment of the bacteria; they are integral components in the respiratory chain donating electrons to the terminal cytochrome oxidase. J Egypt Soc Parasitol, 1994 Aug, 24(2), 247 - 57 Isolation and identification of free-living amoebae from some water sources in Alexandria; Sadaka HA et al.; Samples from different water sources of Alexandria, and from nasal passages of 500 healthy children inhabiting areas nearby these sources were examined for the presence of free-living amoebae . These samples were cultured on 1.5% non nutrient agar streaked with bacteria . Amoebae were isolated and identified by means of their morphological characters and ability to produce flagellated forms . Characteristics of the cystic stages and pattern of excystation also aided in the identification of the various species . Nine species, Naegleria gruberi, N . fowleri, Acanthamoeba rhysodes, A . glebae, A . culbertsoni, A . astronyxis, A . palestinensis, V . avara and V . inornata were isolated from the water of canals and drains . N . gruberi and A . rhysodes were found in the nasal passages of six healthy children living near the contaminated canals . No amoebae were encountered in the drinking water, swimming pools, sea and lake water included in this study. Plant Mol Biol, 1994 Aug, 25(5), 855 - 64 A protein involved in co-ordinated regulation of inorganic carbon and glucose metabolism in the facultative photoautotrophic cyanobacterium Synechocystis PCC6803; Beuf L et al.; The involvement of a gene of Synechocystis PCC6803, icfG, in the co-ordinated regulation of inorganic carbon and glucose metabolism, was established . The icfG gene codes for a 72 kDa protein, which shows no homology with those registered in data libraries . Expression of icfG required glucose, the actual inducer probably being glucose-6-phosphate, and was independent of light and of the external inorganic carbon concentration . Mutants carrying an inactivated copy of icfG were constructed . Their growth characteristics were identical to those of the wild type under all regimes except in limiting inorganic carbon with glucose being present either before or after the transfer to the limiting conditions . These conditions completely prevented growth, both in the light and in the dark . The inhibition could be relieved by several intermediates of the tricarboxylic acid cycle . Assays of various enzymic activities related to inorganic carbon uptake and to its assimilation via either the Calvin cycle or phosphoenolpyruvate carboxylase did not reveal the level of action of IcfG . Possible models include a blockage of the assimilation of both carbon sources in the absence of IcfG, or the inhibition of Ci incorporation route(s) essential under limiting inorganic carbon conditions, even when glucose is present, and even in the dark. Food Chem Toxicol, 1994 Aug, 32(8), 685 - 96 Safety evaluation of lipase G from Penicillium camembertii; Kondo M et al.; Lipase G, a partial glycerides eliminating enzyme produced by Penicillium camembertii, was subjected to safety evaluation studies to establish its safety when used as a processing aid in the food industry . The toxicological studies on the enzyme included a 90-day gavage study with rats, a mutagenicity study using bacteria, and a pathogenicity study using mice . The no-adverse-effect level from the 90-day gavage toxicity study was 2000 mg/kg body weight/day for rats . There was no evidence of mutagenic potential . The micro-organism was evaluated for pathogenicity using mice and classified as a non-pathogen . Results indicate that the production and use of lipase G may be regarded as safe for the enzyme production worker and the consumer. J Am Dent Assoc, 1994 Aug, 125(8), 1071 - 8 Current concepts in periodontal disease testing; Jeffcoat MK; Tests for periodontal disease fall into four categories . The test may identify putative periodontopathic plaque bacteria, the susceptible host, metabolic changes associated with inflammation, tissue damage or death or anatomic changes including periodontal probing and radiographs . The current understanding of tests for periodontal disease is reviewed within a framework for understanding the rationale for such tests. Am J Obstet Gynecol, 1994 Aug, 171(2), 365 - 70; discussion 370-1 Low amniotic fluid glucose levels are a specific but not a sensitive marker for subclinical intrauterine infections in patients in preterm labor with intact membranes; Greig PC et al.; OBJECTIVE: The purpose of this study was to evaluate the ability of a low amniotic fluid glucose level, as defined by previously published thresholds, to identify a subclinical intrauterine infection in women in preterm labor with intact membranes . STUDY DESIGN: Amniotic fluid glucose levels, amniotic fluid cultures, and placental histologic characteristics were determined in women with preterm labor (n = 55) and in preterm controls (n = 58) . These amniotic fluid glucose levels were compared between women with and without intrauterine infection using the Mann-Whitney U test . The sensitivity, specificity, and positive and negative predictive values for the identification of an intrauterine infection were determined with four different previously published amniotic fluid glucose threshold levels and the threshold from receiver-operator characteristic curve analysis of the study data . RESULTS: The median amniotic fluid glucose level was significantly lower in patients with positive amniotic fluid cultures (intraamniotic infection group) but was not lower in the group of patients with only histologic chorioamnionitis (extra-amniotic infection group), compared with noninfected controls . The sensitivity of a low amniotic fluid glucose level to detect both types of intrauterine infection ranged from 41% to 55%, depending on the threshold used . The specificity of a low amniotic fluid glucose level to detect an intrauterine infection ranged from 94% to 100%, the positive predictive value ranged from 86% to 100%, and the negative predictive value ranged from 70% to 80% with the same thresholds . CONCLUSION: Low amniotic fluid glucose levels are a specific but not a sensitive marker for either intraamniotic or extra-amniotic intrauterine infections in patients with preterm laborPIP: Between August, 1991, and November, 1992, in North Carolina, obstetricians performed amniocentesis on 55 women in preterm labor with intact membranes at 24-34 weeks gestation to test for a subclinical intrauterine infection . They compared the amniocentesis results with those of 58 controls at the same gestational age to determine whether low amniotic fluid glucose levels would identify intraamniotic infection or extraamniotic infection . Women with intraamniotic infection had a considerably lower median amniotic fluid glucose level than did those with extraamniotic infection (chorioamnionitis), those with preterm labor but no infection, and the controls (2 vs . 25.5, 33, and 34 mg/dl, respectively; p = .017 for chorioamnionitis group and p .001 for both groups with no infection) . The researchers used 4 different threshold values to determine sensitivity, specificity, positive predictive value, and negative predictive value (= or 5 mg/dl, = or 10 mg/dl, = or 14 mg/dl, and = or 16 mg/dl) . Depending on the threshold level, the sensitivity of a low amniotic fluid glucose level to detect intraamniotic infection and chorioamnionitis varied from 41 to 55% . The specificity of a low amniotic fluid glucose level to detect these infections was 94-100% . The positive and negative predictive values were 86-100% and 70-80%, respectively . These findings show that a low amniotic fluid glucose level can correctly identify patients in preterm labor who do not have intraamniotic infection or chorioamnionitis, but it does not correctly identify preterm labor patients with intrauterine or extrauterine infection . J Neuroimmunol, 1994 Aug, 53(1), 9 - 16 Human IgG monoclonal autoantibodies against muscle acetylcholine receptor: direct evidence for clonal heterogeneity of the antiself humoral response in myasthenia gravis; Cardona A et al.; Human hybridomas were established from myasthenia gravis (MG) patients and screened using a fast and sensitive cell ELISA with the rhabdomyosarcoma cell line TE671 . In a first series of 14 fusions using a standard protocol, 36 positive clones were detected and maintained for three passages . The number of clones in each fusion was correlated with in vivo titers of anti-acetylcholine receptor (AChR) autoantibodies . In a second series of four experiments, fusions were immediately followed by cell plating under limiting dilution conditions ('fusion cloning') providing eight stable hybridomas . These hybridomas produced monoclonal antibodies (mAbs) of IgG isotype reactive with TE671 cells, but not with AChR in solution using the radioimmunoprecipitation assay . Fine analysis of antigen specificity of these mAbs was performed using solid-phase ELISA against purified AChR from Torpedo (T-AChR) and immunoblot against recombinant chimaeric human AChR produced in bacteria . Five of the eight mAbs derived from the few patients whose antibodies showed cross-reactivity with T-AChR reacted against T-AChR . Of these five mAbs, two also reacted against chimaeric human AChR by immunoblotting . Furthermore, at least one of these two mAbs was capable of inducing antigenic modulation of labeled AChR with {125I}alpha-bungarotoxin from the surface of TE671 cells . These mAbs provide useful tools to explore the molecular basis of the structural and functional heterogeneity of the humoral anti-AChR response in myasthenia gravis. J Bacteriol, 1994 Aug, 176(16), 5171 - 6 The Rhodobacter capsulatus glnB gene is regulated by NtrC at tandem rpoN-independent promoters; Foster-Hartnett D et al.; The protein encoded by glnB of Rhodobacter capsulatus is part of a nitrogen-sensing cascade which regulates the expression of nitrogen fixation genes (nif) . The expression of glnB was studied by using lacZ fusions, primer extension analysis, and in vitro DNase I footprinting . Our results suggest that glnB is transcribed from two promoters, one of which requires the R . capsulatus ntrC gene but is rpoN independent . Another promoter upstream of glnB is repressed by NtrC; purified R . capsulatus NtrC binds to sites that overlap this distal promoter region. J Bacteriol, 1994 Aug, 176(16), 4803 - 8 Loci of Mycobacterium avium ser2 gene cluster and their functions; Mills JA et al.; The highly antigenic glycopeptidolipids present on the surface of members of the Mycobacterium avium complex serve to distinguish these bacteria from all others and to define the various serovars that compose this complex . Previously, the genes responsible for the biosynthesis of the disaccharide hapten {2,3-di-O-methyl-alpha-L-fucopyranosyl-(1-->3)-alpha-L-rhamnopyranose} of serovar 2 of the M . avium complex were isolated, localized to a contiguous 22- to 27-kb fragment of the M . avium genome, and designated the ser2 gene cluster (J . T . Belisle, L . Pascopella, J . M . Inamine, P . J . Brennan, and W . R . Jacobs, Jr., J . Bacteriol . 173:6991-6997, 1991) . In the present study, transposon saturation mutagenesis was used to map the specific genetic loci within the ser2 gene cluster required for expression of this disaccharide . Four essential loci, termed ser2A, -B, -C, and -D, constituting a total of 5.7 kb within the ser2 gene cluster, were defined . The ser2B and ser2D loci encode the methyltransferases required to methylate the fucose at the 3 and 2 positions, respectively . The rhamnosyltransferase was encoded by ser2A, whereas either ser2C or ser2D encoded the fucosyltransferase . The ser2C and ser2D loci are also apparently involved in the de novo synthesis of fucose . Isolation of the truncated versions of the hapten induced by the transposon insertions provides genetic evidence that the glycopeptidolipids of M . avium serovar 2 are synthesized by an initial transfer of the rhamnose unit to the peptide core followed by fucose and finally O methylation of the fucosyl unit. Infect Immun, 1994 Aug, 62(8), 3586 - 9 A urease-negative mutant of Helicobacter pylori constructed by allelic exchange mutagenesis lacks the ability to colonize the nude mouse stomach; Tsuda M et al.; The urease of Helicobacter pylori has been proposed to be one of its pathogenic factors . A kanamycin resistance determinant was inserted in a cloned urease gene, and transformation-mediated allelic exchange mutagenesis was carried out to introduce the disrupted gene into the corresponding wild-type chromosomal region of a clinical isolate of H . pylori, CPY3401 . The resulting mutant, HPT73, had the null activity of urease . Nude mouse stomachs were challenged with these two isogenic strains to examine the role of urease in pathogenesis . Gastritis was found in the CPY3401-challenged stomachs, from which bacteria indistinguishable from CPY3401 were recovered . There was no gastritis in the HPT73-challenged stomachs, and we could not recover H . pylori from them . These results indicated that H . pylori urease is essential for colonizing the nude mouse stomach. Infect Immun, 1994 Aug, 62(8), 3381 - 90 BvgAS-mediated signal transduction: analysis of phase-locked regulatory mutants of Bordetella bronchiseptica in a rabbit model; Cotter PA et al.; Members of the Bordetella genus alternate between two distinct phenotypic phases in response to changes in their environment . This switch, termed phenotypic modulation, is mediated by the BvgAS sensory transduction system . We developed an animal model based on the interaction of Bordetella bronchiseptica with one of its natural hosts, the rabbit . To investigate the importance of BvgAS signal transduction, we constructed constitutive (RB53) and Bvg- (RB54) phase-locked derivatives of a wild-type strain, RB50 . RB50 and RB53, but not RB54, established respiratory infections in B . bronchiseptica-free rabbits with an intranasal 50% infective dose of less than 200 organisms, and the course of the infection closely resembled that observed with naturally infected rabbits . Bacteria were recovered from the nasal cavity, larynx, trachea, and lungs in similar numbers from RB50- and RB53-infected rabbits, yet no pathology was detected by histological examination of lung and tracheal sections . The antibody responses in rabbits inoculated with RB50 or RB53 were quantitatively and qualitatively indistinguishable; high titers of antibodies were generated primarily against Bvg(+)-phase-specific antigens . No response against flagella, a Bvg- phase factor, was detected . Assessment of bacteria associated with alveolar macrophages indicated that only a small percentage of bacteria, if any, appear to be residing within lung macrophages . We also tested the ability of these strains to survive in a nutrient poor environment, conditions which may be encountered within certain niches in the host or in an environmental reservoir . The Bvg- phase was advantageous for growth under these conditions . Our results indicate the Bvg+ phase is sufficient for establishment of respiratory tract infection in the rabbit and the normal BvgAS-mediated response to environmental signals is not required during initial colonization . The Bvg- phase may play a role at later stages of infection, including persistence, transmission, or survival in the environment. Infect Immun, 1994 Aug, 62(8), 3254 - 61 Growth of Legionella pneumophila in Acanthamoeba castellanii enhances invasion; Cirillo JD et al.; Legionella pneumophila is considered to be a facultative intracellular parasite . Therefore, the ability of these bacteria to enter, i.e., invade, eukaryotic cells is expected to be a key pathogenic determinant . We compared the invasive ability of bacteria grown under standard laboratory conditions with that of bacteria grown in Acanthamoeba castellanii, one of the protozoan species that serves as a natural host for L . pneumophila in the environment . Amoeba-grown L . pneumophila cells were found to be at least 100-fold more invasive for epithelial cells and 10-fold more invasive for macrophages and A . castellanii than were L . pneumophila cells grown on agar . Comparison of agar- and amoeba-grown L . pneumophila cells by light and electron microscopy demonstrated dramatic differences in the morphology and structure of the bacteria . Analyses of protein expression in the two strains of bacteria suggest that these phenotypic differences may be due to the expression of new proteins in amoeba-grown L . pneumophila cells . In addition, the amoeba-grown bacteria were found to enter macrophages via coiling phagocytosis at a higher frequency than agar-grown bacteria did . Replication of L . pneumophila in protozoans present in domestic water supplies may be necessary to produce bacteria that are competent to enter mammalian cells and produce human disease. Infect Immun, 1994 Aug, 62(8), 3206 - 12 Immune and pathologic responses in mice infected with Brucella abortus 19, RB51, or 2308; Stevens MG et al.; Immune and pathologic responses were measured for 20 weeks after infection of mice with Brucella abortus 19, RB51, or 2308 . Live bacteria and bacterial antigens of 19 and RB51 persisted in spleens for 10 and 4 weeks after infection, respectively, whereas 2308 bacteria and bacterial antigens persisted for at least 20 weeks . Small germinal centers and profound lymphoid depletion occurred in spleens of mice during the first 4 weeks of infection with strain 19 or 2308; however, mice infected with strain RB51 had much larger germinal centers but no lymphoid depletion . At 4 weeks, only spleen cells from RB51-infected mice proliferated when incubated with 2308 bacteria . Large germinal centers in the spleen and spleen cell proliferative responses to 2308 did not appear in strain 19-infected mice until 6 weeks or in strain 2308-infected mice until 10 weeks . Similar proliferative responses to 2308 occurred in mice infected with strain 19 or RB51 at 6 weeks and in mice infected with strain 19, RB51, or 2308 at 10 weeks . However, at 20 weeks, spleen cell proliferative responses to 2308 occurred in mice infected with strain 19 or 2308 but not in mice infected with strain RB51 . Mice infected with strain RB51 had lower and less persistent antibody titers to 2308 than did mice infected with strain 19 or 2308 . Collectively, these results indicate that RB51-infected mice have less persistent immune responses to 2308 than do mice infected with 19 or 2308 . The shorter duration of the responses probably resulted because RB51 is considerably less pathogenic and is cleared more rapidly from mice than are 19 and 2308. Infect Immun, 1994 Aug, 62(8), 3129 - 37 Transfer of immunity against lethal murine Francisella infection by specific antibody depends on host gamma interferon and T cells; Rhinehart-Jones TR et al.; Both serum and spleen cells from mice immune to Francisella tularensis transfer protection to naive recipients . Here we characterize the mechanism of protection induced by transfer of immune mouse serum (IMS) . IMS obtained 4 weeks after intradermal infection with 10(3) bacteria of the live vaccine strain (LVS) contained high levels of immunoglobulin G2 (IgG2a) and IgM (end point titers, 1:16,600 and 1:7,200, respectively) and little IgG1, IgG2b, or IgG3 . LVS-specific antibodies were detected 5 days after intradermal infection, and reached peak levels by 2 weeks postinfection . Only sera obtained 10 days or more after sublethal infection, when IgG titers peaked, transferred protection against a challenge of 100 50% lethal doses (LD50s) . Purified high-titer IgG anti-LVS antibody but not IgM anti-LVS antibody was responsible for transfer of protection against an intraperitoneal challenge of up to 3,000 LD50s . IMS had no direct toxic effects on LVS and did not affect uptake or growth of bacteria in association with peritoneal cells . One day after LVS infection, liver, spleen, and lung tissue from mice treated with IMS contained 1 to 2 log units fewer bacteria than did tissue from mice treated with normal mouse serum or phosphate-buffered saline . Between 2 and 4 days after infection, however, bacterial growth rates in tissues were similar in both serum-protected mice and unprotected mice . Bacterial burdens in IMS-treated, LVS-infected mice declined in infected tissues after day 5, whereas control animals died . This lag phase suggested that development of a host response was involved in complete bacterial clearance . In fact, transfer of IMS into normal recipients that were simultaneously treated with anti-gamma interferon and challenged with LVS did not protect mice from death . Further, transfer of IMS into athymic nu/nu mice did not protect against LVS challenge; protection was, however, reconstituted by transfer of normal T cells into nu/nu mice . Thus, "passive" transfer of protection against LVS with specific antibody is not passive but depends on a host T-cell response to promote clearance of systemic infection and protection against lethal disease. Arch Biochem Biophys, 1994 Aug 1, 312(2), 524 - 33 Structural analysis of transcripts for the protein L-isoaspartyl methyltransferase reveals multiple transcription initiation sites and a distinct pattern of expression in mouse testis: identification of a 5'-flanking sequence with promoter activity; Galus A et al.; The gene encoding the protein L-isoaspartyl-(D-aspartyl) methyltransferase (protein carboxyl methyltransferase, PCMT) is widely expressed in bacteria and eucaryotic cells . An antisense probe encompassing the first exon of the murine PCMT gene {E . A . Romanik, C . L . Ladino, S . C . D'Ardenne, and C . M . O'Connor (1992) Gene 118, 217-222} was used in ribonuclease protection assays to identify the initiation sites for PCMT transcription in mouse testis, brain, and liver tissues . Two major initiation sites, 155-157 nucleotides (nt) and 119 nt upstream from the ATG initiation codon, were identified in all tissues in addition to several minor sites . The locations of the initiation sites in testicular RNA were confirmed using ligation-mediated 5'-rapid amplification of cDNA ends (RACE) . These initiation sites are situated at the 3'-end of a 407-bp genomic sequence which is sufficient to drive the expression of a firefly luciferase gene in transient transfection assays with NIH/3T3 cells . The 407-bp sequence resembles a housekeeping gene promoter in its high G+C content, lack of a TATA box and the presence of multiple potential binding sites for the transcription factors Sp1 and ETF . Alternative splicing in the C-terminal encoding sequence and in the 3'-untranslated regions of PCMT transcripts generates three distinct classes of mRNAs which were cloned from testicular poly(A)+ RNA using 3'-RACE . Transcript splicing either 38 nt downstream or 7 nt upstream from the termination codon in exon 7 produces mRNAs encoding PCMT isozymes with -RWK or -RDEL, respectively, at their C-termini . The predominant transcript in testis, which is not detected in somatic tissues by Northern blotting and which may be specific to germ cells, is not spliced within exon 7 and also encodes the -RWK isozyme. Virology, 1994 Aug 1, 202(2), 1003 - 6 Detection of the readthrough protein of barley yellow dwarf virus; Cheng SL et al.; The single open reading frame (ORF) 5 encoding the 50-kDa protein of barley yellow dwarf virus PAV-IL (BYDV-PAV-IL) was expressed in bacteria, purified, and used as an immunogen/antigen to produce/screen antibodies specific to the 50-kDa protein . Two monoclonal antibodies (MAb PAV-IL-22 kDa and MAb PAV-IL-50 kDa) raised against BYDV-PAV-IL could specifically detect the presence of the 72-kDa readthrough protein in extracts from the BYDV-infected leaf tissue . The results suggest that ORF 5 (50-kDa protein) is translated by readthrough of ORF 3 (22-kDa coat protein) to produce the 72-kDa protein . The readthrough protein is thought to be a structural protein on the external surface of BYDV. Mol Microbiol, 1994 Aug, 13(4), 619 - 26 Redundancy of the conserved His residue in Azotobacter vinelandii NifL, a histidine autokinase homologue which regulates transcription of nitrogen fixation genes; Woodley P et al.; The NifL protein of Azotobacter vinelandii inhibits NifA, the activator of nif (nitrogen fixation) transcription, in response to oxygen and fixed nitrogen . NifL shows strong homology in its C-terminal domain to the histidine autokinase domains of the canonical two-component sensor proteins, including the region around His-304, which corresponds to the residue known to be phosphorylated in other systems . To examine the mechanism of sensory transduction by NifL, mutations encoding 10 substitutions for His-304 were introduced into the A . vinelandii chromosome . Regulation of nif transcription was measured using acetylene reduction and RNA blots . The substitutions His-304-->Arg and His-304-->Pro impaired regulation by both fixed nitrogen and oxygen, but substitution of Ala, Phe, Ile, Lys, Asn, Ser, Thr, Val had no effect . None of the mutants, including His-304-->Arg and His-304-->Pro, excreted ammonium during diazotrophy, a phenotype of nifL deletion mutants, suggesting that the molecular basis of this effect differs from that responsible for the inhibition of nif transcription . The data show conclusively that phosphorylation of His-304 is not essential for any of the known functions of A . vinelandii NifL . Homology to the family of histidine autokinases is therefore inadequate evidence for a mechanism of sensory transduction involving phosphorylation of the conserved histidine residue. J Endod, 1994 Aug, 20(8), 381 - 5 Effect of IRM root end fillings on healing after replantation; Pitt Ford TR et al.; The effect of IRM as a root end filling placed in teeth prior to replantation was examined in 21 molar teeth in monkeys . After extraction, root ends were resected, the canals contaminated with oral bacteria, root end cavities prepared, and fillings of IRM or amalgam placed prior to replantation . After 8 wk the jaws were removed and prepared for histological examination . Bacteria were demonstrated in only 9 of 15 teeth filled with IRM; 18 of the roots (60%) were associated with inflammation, which was only moderate or severe around 5 (17%), and extended > 0.1 mm around only 2 roots . In contrast, of the 6 teeth filled with amalgam, all contained bacteria in the root canals and 11 roots were associated with moderate or severe inflammation, which around 8 roots extended > 0.5 mm . The difference in severity of inflammation for the two materials was statistically significant (p < 0.001) . The tissue response to root end fillings of IRM in replanted teeth was less severe and less extensive than that to amalgam. Khirurgiia (Mosk), 1994 Aug, (8), 48 - 52 {Laser and ultrasonic therapy in the treatment of acute purulent diseases of the soft tissues in children}; Rakhimov AU et al.; The article analyses the results of active treatment of pyoinflammatory diseases in 138 children by means of CO2-laser and ultrasonic cavitation . The control group was formed of 145 children who were treated by the commonly applied methods . The efficacy of surgical debridement was appraised according to the number of bacteria per g of tissues . Various methods of opening and treatment of the purulent cavity are compared . The differentiated use of the laser beam and ultrasonic cavitation depending on the character of the pathological process is substantiated . The schemes of ultrasonic cavitation with the use of various solutions and their combination depending on the phase of the wound process are shown . A combination of laser cleansing and ultrasonic cavitation is most rational . Complete epithelialization of the wound occurs 5-6 days earlier than in the control group. Khirurgiia (Mosk), 1994 Aug, (8), 18 - 21 {Hirschsprung's disease in newborns}; Stepanov EA et al.; The authors examined and treated 52 newborn babies and infants with Hirschsprung's disease . The total form was encountered in 25%, the subtotal in 23.1%, the rectosigmoid in 36.5%, the rectal in 9.6%, and the supraanal in 5.8% of cases . The clinical picture was characterized by retention of meconium (94.2%), regurgitation or vomiting (75%), abdominal distention (100%) . Irrigography with calculation of the rectosigmoid ratio was conducted in 35 children, histochemical examination in 46, and histological examination in 38 children . Twenty-four (68.5%) children had the third phase of disturbed proportion of the intestinal bacteria with clinical manifestations of enterocolitis . Emergency decompression of the intestine for low acute intestinal obstruction was carried out in 27 newborn babies . Twenty children were subjected to radical surgery in the first 2-4 months of life . The choice of the operative method was guided by the form of the disease and the length of the aganglionic zone. Curr Opin Cell Biol, 1994 Aug, 6(4), 499 - 509 Post-translational protein import and folding; Hohfeld J et al.; Significant advances have been made over the past year in analyzing the membrane machineries for the post-translational export of proteins in bacteria and for the import of proteins into mitochondria . Another important development is the identification in mitochondria of homologs of the bacterial heat-shock proteins DnaJ and GrpE, which function together with Hsp70 in membrane translocation and folding of imported proteins . A number of gene products involved in peroxisomal protein uptake have been identified, which are now awaiting biochemical analysis. Biotechniques, 1994 Aug, 17(2), 316, 318, 320 - 2 A nontoxic and versatile protein salting-out method for isolation of DNA; Laitinen J et al.; A pivotal technique in basic and applied molecular biology is the isolation of DNA . However, the present DNA extraction methods are either toxic, expensive, time-consuming and laborious or restricted to certain applications . Here we describe a nontoxic and versatile protein salting-out method for convenient and rapid extraction of large as well as small DNA molecules from vertebrate cells and plasmid DNA from bacteria . Easy and relatively imprecise manipulations of a large number of samples result in high yields of pure mammalian and plasmid DNA that are suitable for transformation of bacteria, restriction enzyme analyses, Southern blotting, end labeling of DNA, PCR and sequencing. Vet Microbiol, 1994 Aug 1, 41(3), 205 - 12 Polymerase chain reaction for diagnosis of porcine proliferative enteropathy; McOrist S et al.; A polymerase chain reaction (PCR) assay for detection of the intracellular bacteria, ileal symbiont intracellularis of porcine proliferative enteropathy is described . The test is based on specific DNA primers and gave positive PCR product from samples of preserved intestinal mucosa and faeces from affected pigs . Mucosa and faeces from normal pigs gave no positive PCR products . The identity of the PCR product was confirmed by DNA-DNA hybridization with a probe, pCLO78, specific for IS intracellularis . Positive results were only observed in animals with active lesions of proliferative enteropathy . PCR is probably the most useful method for diagnosis of proliferative enteropathy that is currently available for live animals. Ryumachi, 1994 Aug, 34(4), 779 - 85 {Hemophagocytic syndrome observed in a patient with systemic lupus erythematosus}; Hayashi S et al.; A 52-year-old woman was admitted to our hospital because of a skin rash, high fever and myalgia . She had been diagnosed ten years ago by a dermatologist as having MCTD (mixed connective tissue disease) . At the time of admission a diagnosis of active SLE was made by fulfilling four of the 1982 ARA criteria together with increasing levels of anti-DNA antibody and low levels of complements . Prednisolone (PSL) given orally in an initial dosage of 60 mg/day was effective during the first 6 weeks . Then a high fever, skin rash and pancytopenia appeared without active findings of SLE . Infection caused by bacteria, fungus or virus was suspected, but no infectious agent was present in cultures derived from blood or other sources . Antimicrobic drugs used were not effective at all . The clinical picture was suggestive of a drug allergy, but no causative drug was found . A diagnosis of hemophagocytic syndrome (HPS) was made because of the increased number of unusual hemophagocytic cells in the bone marrow . High levels of serum ferritin and neopterin, which are known to reflect macrophage activation, supported the diagnosis of HPS . HPS is characterized by activated phagocytosis presumably induced by hypersecretion of cytokines . Malignant lymphoma and infection are the two representative diseases which may cause HPS . Recently, an acute lupus HPS was reported in patients with active SLE . Here we reported a case of reactive HPS observed in a patient with SLE who had been receiving high dose PSL . Symptoms and findings of the patient gradually disappeared in several weeks after rapid reduction of the PSL dose.(ABSTRACT TRUNCATED AT 250 WORDS) Poult Sci, 1994 Aug, 73(8), 1254 - 9 Age-related changes in the incidence of tibial dyschondroplasia in turkeys; Rath NC et al.; Age-related changes in the incidence and severity of tibial dyschondroplasia (TD) and its relationship to body weight and other bone pathologies were studied in turkeys from ages 2 through 15 wk . A steady increase in the incidence and severity of TD was observed from 11 wk onwards . Whereas there was no correlation between the body weight and TD in early ages, during Weeks 14 and 15 the turkeys with severe TD had significantly higher body weight relative to those without or with mild lesions . Starting from Week 13, hemorrhage was evident in the base of TD-affected growth plates of many turkeys, which increased linearly during the following weeks . Histological examination of these areas revealed mild necrosis with erosion in TD tissues accompanied by occasional bone formations, fibrosis, and the presence of multinucleate chondroclasts and large number of erythrocytes adjacent to lesions . Sporadic rod-like bacterial colonies were discernible in TD tissues and cartilage canals . These studies show 1) whereas the onset of TD may have an independent etiology, the severity of the disease may be influenced by a higher body weight; and 2) subepiphyseal hemorrhages possibly facilitate a healing-type response that leads to replacement of TD tissue by way of resorption, bone formation, and fibrosis, but simultaneously makes the tissue accessible to bacteria. J Vet Pharmacol Ther, 1994 Aug, 17(4), 279 - 83 Pharmacokinetic and toxicological aspects of the medication of beef-type calves with an oral formulation of chloramphenicol palmitate; Gassner B et al.; Chloramphenicol (CAP) plasma levels were determined after oral administration of four doses of CAP palmitate (each dose corresponding to CAP 25 mg/kg/12 h) to four ruminating beef-type calves . Steady-state plasma concentrations of CAP were reached after the fourth oral dose and varied between 5 and 6 micrograms/ml . Half-life of elimination of CAP was 4.5 h . In addition to CAP, dehydrochloramphenicol (DH-CAP), a metabolite of chloramphenicol, was detected in plasma at concentrations between 3 and 7 ng/ml . DH-CAP is known to be produced from CAP by intestinal bacteria . This is significant since DH-CAP is suspected of being involved in the development of fatal aplastic anaemia, which occurs in man after exposure to CAP . Thus, it cannot be excluded that DH-CAP residues may occur in edible tissues . A risk arising from DH-CAP can neither be excluded for the animals being treated with CAP nor for consumers. J Dent, 1994 Aug, 22(4), 223 - 8 Effect of gingival fluid collection on subgingival plaque sampling; Mullally B et al.; The purpose of this study was to determine whether gingival crevicular fluid (GCF) sampling by paper strip removes sufficient bacteria to affect subsequent subgingival plaque sampling using a curette . In 25 subjects, one healthy, gingivitis and periodontitis site was sampled for GCF using a strip followed by subgingival plaque sampling with a curette . Bacterial assays indicated that GCF strips removed significant numbers of bacteria when placed intracrevicularly for 5 s . A greater proportion of total bacteria was removed with strip sampling at healthy rather than gingivitis or periodontitis sites . Qualitative assessment of presence or absence of spirochaetes and dark-pigmented species indicated potential for significant interference of curette sampling by the strip at gingivitis and healthy sites . We concluded that paper strip GCF sampling may significantly affect curette sampling at the same sites . The magnitude of this impact depended on the clinical classification of specific sites and the assay performed. J Clin Pathol, 1994 Aug, 47(8), 699 - 704 Electron microscopic study of association between Helicobacter pylori and gastric and duodenal mucosa; Noach LA et al.; AIM--To study the ultrastructural appearances of Helicobacter pylori in antral and duodenal biopsy specimens and its relation with the epithelial cells . METHODS--Endoscopically obtained antral and duodenal biopsy specimens were examined using transmission electron microscopy and freeze fracture analysis . RESULTS--Most bacteria looked curved, but in the duodenal bulb coccoid bacteria were relatively common . Bacteria were often found around intercellular junctions . freeze fracture examination indicated abnormalities of the tight junction complexes in patients with H pylori infection . In many biopsy specimens bacteria were seen closely attached to the epithelial cell membrane by different forms of adhesion . In addition to what looked like intracytoplasmic penetration by bacteria, several examples of genuine penetration were observed . CONCLUSION--H pylori is commonly found adhering to epithelial cells . Occasionally, H pylori may also penetrate cells . These features may contribute to the pathogenic action of the organism. Genes Dev, 1994 Aug 1, 8(15), 1839 - 52 A sigma 54 transcriptional activator also functions as a pole-specific repressor in Caulobacter; Wingrove JA et al.