Antonie Van Leeuwenhoek, 1998 Apr, 73(3), 223 - 8 Biochemical alterations in Bradyrhizobium sp USDA 3187 induced by the fungicide Mancozeb; Fabra A et al.; We have previously shown that fungicide Mancozeb causes a 50% decrease in Bradyhizobium sp USDA 3187 growth rate and affects the bacteria-root symbiotic interaction . In order to elucidate the fungicide toxicity mechanism we determined the effects of Mancozeb on cell chemical composition, glutathione (GSH) content (molecule involved in the detoxification process), glutathione S-transferase (GST) activity and on polyamine, exopolysaccharides, capsular polysaccharides and lipopolysaccharides . Mancozeb produced biochemical alterations in membrane composition, polysaccharides and polyamines . In spite of the increment of GSH content and GST activity, they are not enough to prevent the growth diminution. J Neurosci, 1998 Nov 15, 18(22), 9238 - 44 A memory for extracellular Ca2+ by speeding recovery of P2X receptors from desensitization; Cook SP et al.; Nerve endings of nociceptors (pain-sensing neurons) express an unusual subtype of ATP-gated ion channel, the P2X3 receptor, that rapidly desensitizes (<100 msec) and slowly recovers (>20 min) . Here we show that Ca2+, or certain other polyvalent cations, binds to an extracellular site on rat sensory neurons and can increase current through P2X3 channels more than 10-fold . Importantly, Ca2+ facilitates P2X3 current to precisely the same level whether a transient Ca2+ change occurred just before or several minutes before activating the channels with ATP . This memory for past changes in Ca2+ is integrative in that a 90 sec Ca2+ stimulus delivered just before an ATP application has the same effect as an earlier series of three, separated 30 sec Ca2+ stimuli . These diverse phenomena are explained by a single mechanism: Ca2+ speeds recovery of P2X channels from desensitization . Recovery follows an exponential growth curve that depends on the duration, but not the timing, of changes in recovery rate . Modulation of desensitization underlies a well described short-term memory in bacteria, and it might be similarly used in the nervous system. Infect Control Hosp Epidemiol, 1998 Oct, 19(10), 805 - 7 Economic consequences of hospital infections in a 1,000-bed university hospital in Norway; Andersen BM; Hospital infections were studied among 41,000 patients admitted to a 1,000-bed university hospital in Oslo, Norway . A prevalence rate of 8.5% in 1995 contributed to 14,500 days of extra stay in the hospital . The direct economic consequences of hospital infections was 40 to 50 million Norwegian kroner ($6-$7 million) . The extra direct cost per infected patient was 14,300 Norwegian kroner ($2,200) . Hospital infections are generating high extra costs and morbidity in countries with good general health care and with few problems with resistant bacteria. Philos Trans R Soc Lond B Biol Sci, 1998 Sep 29, 353(1374), 1405 - 12 The ethylene-receptor family from Arabidopsis: structure and function; Bleecker AB et al.; The gaseous hormone ethylene regulates many aspects of plant growth and development . Ethylene is perceived by a family of high-affinity receptors typified by the ETR1 protein from Arabidopsis . The ETR1 gene codes for a protein which contains a hydrophobic N-terminal domain that binds ethylene and a C-terminal domain that is related in sequence to histidine kinase-response regulator two-component signal transducers found in bacteria . A structural model for the ethylene-binding domain is presented in which a Cu(I) ion is coordinated within membrane-spanning alpha-helices of the hydrophobic domain . It is proposed that binding of ethylene to the transition metal would induce a conformational change in the sensor domain that would be propagated to the cytoplasmic transmitter domain of the protein . A total of four additional genes that are related in sequence to ETR1 have been identified in Arabidopsis . Specific missense mutations in any one of the five genes leads to ethylene insensitivity in planta . Models for signal transduction that can account for the genetic dominance of these mutations are discussed. Semin Immunol, 1998 Oct, 10(5), 373 - 81 Mast cells and basophils in innate immunity; Abraham SN et al.; Mast cells and basophils are primarily associated with the pathophysiology of allergic diseases . Considering that these cells have been preserved through evolution they must serve a valuable function . Intrinsically, mast cells are ideally placed and well endowed with inflammatory mediators to play a critical role in immune surveillance . Recent studies have shown that mast cells and basophils can bind various bacteria even in the absence of opsonizing antibodies . The resulting interaction caused release of a variety of inflammatory mediators and, in the case of mast cells, also uptake of bacteria . Among the mediators released by these inflammatory cells, TNF-alpha appears critical as it potentiates the early neutrophil responses to bacteria . Observations in mutant mice that are deficient in mast cells has provided further evidence for the specific role of mast cells in host defense against bacteria . We believe that there is now sufficient evidence (at least for mast cells) to propose a multi-faceted and significant role for these cells in the host's innate immune response to infectious agents . Eur J Biochem, 1998 Oct 1, 257(1), 202 - 9 Stopped-flow kinetics of hydride transfer between nucleotides by recombinant domains of proton-translocating transhydrogenase; Venning JD et al.; Transhydrogenase catalyses the transfer of reducing equivalents between NAD(H) and NADP(H) coupled to proton translocation across the membranes of bacteria and mitochondria . The protein has a tridomain structure . Domains I and III protrude from the membrane (e.g . on the cytoplasmic side in bacteria) and domain II spans the membrane . Domain I has the binding site for NAD+/NADH, and domain III for NADP+/NADPH . We have separately purified recombinant forms of domains I and III from Rhodospirillum rubrum transhydrogenase . When the two recombinant proteins were mixed with substrates in the stopped-flow spectrophotometer, there was a biphasic burst of hydride transfer from NADPH to the NAD+ analogue, acetylpyridine adenine dinucleotide (AcPdAD+) . The burst, corresponding to a single turnover of domain III, precedes the onset of steady state, which is limited by very slow release of product NADP+ (k approximately 0.03 s(-1)) . Phase A of the burst (k approximately 600 s(-1)) probably arises from fast hydride transfer in complexes of domains I and III . Phase B (k approximately 10-50 s(-1)), which predominates when the concentration of domain I is less than that of domain III, probably results from dissociation of the domain I:III complexes and further association and turnover of domain I . Phases A and B were only weakly dependent on pH, and it is therefore unlikely that either the hydride transfer reaction, or conformational changes accompanying dissociation of the I:III complex, are directly coupled to proton binding or release . A comparison of the temperature dependences of AcPdAD+ reduction by {4B-2H}NADPH, and by {4B-1H}NADPH, during phase A shows that there may be a contribution from quantum mechanical tunnelling to the process of hydride transfer . Given that hydride transfer between the nucleotides is direct {Venning, J . D., Grimley, R . L., Bizouarn, T., Cotton, N . P . J . & Jackson, J . B . (1997) J . Biol . Chem . 272, 27535-27538}, this suggests very close proximity of the nicotinamide rings of the two nucleotides in the I:III complex. Eur J Biochem, 1998 Oct 1, 257(1), 160 - 8 Purification and characterization of a flavoprotein involved in the degradation of epoxyalkanes by Xanthobacter Py2; Westphal AH et al.; Recently a newly discovered pyridine nucleotide-disulfide oxidoreductase was reported to be essential for the degradation of epoxyalkanes by the Xanthobacter Py2 {Swaving, J., De Bont, J . A . M., Westphal, A . & De Kok, A . (1996) J . Bacteriol . 178, 6644-6646} . The disulfide oxidoreductase has now been purified from propene-grown Xanthobacter Py2 . This enzyme (component II) is a NADPH-dependent FAD-containing homodimeric protein . The physiological substrate for this enzyme is unknown . The enzyme was active with the following dithiol substrates in decreasing order: 1,3-propanedithiol, reduced lipoamide and dithiothreitol, and inactive with glutathione and monothiols . In the reversed direction, only activity with 5,5'-dithiobis(2-nitrobenzoate) could be measured . Compared with other disulfide reductases it has a high activity with 5,5'-dithiobis(2-nitrobenzoate) and a low diaphorase and oxidase activity . Steady-state kinetic studies at pH 8.5 with 1,3-propanedithiol show that the enzyme operates by a ternary complex mechanism in the direction of NADP+ reduction . Anaerobic incubation of the enzyme with 1,3-propanedithiol resulted in slow reduction of the enzyme to yield the thiolate-FAD charge-transfer complex, the rate depending on the pH . At pH 7, where reduction was not detectable within 2 h, rapid mixing of NADP+ with the enzyme-propanedithiol mixture resulted in the formation of a complex between the reduced enzyme and NADP+ within the dead time of the instrument (5.6 ms) . This is followed by slow formation of NADPH, concomitant with the appearance of the flavin C(4a)-thiol adduct, as judged from the spectral changes . This suggests that the rate-limiting step is the transfer of a hydride ion from the half-reduced enzyme to NADP+ . Stopped-flow experiments involving reduction by NADPH show a biphasic behavior . The rapid formation (k(obs) = 40 s(-1)) of a transient intermediate with little absorption decrease at 460 nm and long wavelength absorption was followed by the slow formation (k(obs) = 4 s(-1)) of a species characterized as the thiolate-FAD charge-transfer complex with bound NADP+ . Some formation of the FAD C(4a)-thiol adduct was also observed . Photoreduction in the presence of deazaflavin results in rapid bleaching at 450 nm, followed by the slow formation of a stable semiquinone . Full reduction could not be achieved, either by photoreduction or with NADPH, and was incomplete even with dithionite or NADPH in the presence of arsenite . The results indicate a low redox potential of the FAD and a slow rate of electron transfer from the pyridine nucleotide to the redox active disulfide and vice versa . From a sequence alignment with other disulfide reductases, it appears that the active site His-Glu diad is absent in this enzyme . The kinetic and spectral features described above will be discussed in this context. J Mol Evol, 1998 Nov, 47(5), 508 - 16 The root of the universal tree of life inferred from anciently duplicated genes encoding components of the protein-targeting machinery; Gribaldo S et al.; The key protein of the signal recognition particle (termed SRP54 for Eucarya and Ffh for Bacteria) and the protein (termed SRalpha for Eucarya and Ftsy for bacteria) involved in the recognition and binding of the ribosome SRP nascent polypeptide complex are the products of an ancient gene duplication that appears to predate the divergence of all extant taxa . The paralogy of the genes encoding the two proteins (both of which are GTP triphosphatases) is argued by obvious sequence similarities between the N-terminal half of SRP54(Ffh) and the C-terminal half of SRalpha(Ftsy) . This enables a universal phylogeny based on either protein to be rooted using the second protein as an outgroup . Phylogenetic trees inferred by various methods from an alignment (220 amino acid positions) of the shared SRP54(Ffh) and SRalpha(Ftsy) regions generate two reciprocally rooted universal trees corresponding to the two genes . The root of both trees is firmly positioned between Bacteria and Archaea/Eucarya, thus providing strong support for the notion (Iwabe et al . 1989; Gogarten et al . 1989) that the first bifurcation in the tree of life separated the lineage leading to Bacteria from a common ancestor to Archaea and Eucarya . None of the gene trees inferred from the two paralogues support a paraphyletic Archaea with the crenarchaeota as a sister group to Eucarya. Appl Environ Microbiol, 1998 Nov, 64(11), 4530 - 2 Methanotrophs and methanogens in masonry Kussmaul M, Wilimzig M, Bock E. Methanotrophs were present in 48 of 225 stone samples which were removed from 19 historical buildings in Germany and Italy . The average cell number of methanotrophs was 20 CFU per g of stone, and their activities ranged between 11 and 42 pmol of CH4 g of stone-1 day-1 . Twelve strains of methane-oxidizing bacteria were isolated . They belonged to the type II methanotrophs of the genera Methylocystis, Methylosinus, and Methylobacterium . In masonry, growth substrates like methane or methanol are available in very low concentrations . To determine if methane could be produced by the stone at rates sufficient to support growth of methanotrophs, methane production by stone samples under nonoxic conditions was examined . Methane production of 0.07 to 215 nmol of CH4 g of stone-1 day-1 was detected in 23 of 47 stone samples examined . This indicated the presence of the so-called "mini-methane"-producing bacteria and/or methanogenic archaea . Methanotrophs occurred in nearly all samples which showed methane production . This finding indicated that methanotrophs depend on biogenic methane production in or on stone surfaces of historical buildings. Appl Environ Microbiol, 1998 Nov, 64(11), 4522 - 9 Kinetic bias in estimates of coastal picoplankton community structure obtained by measurements of small-subunit rRNA gene PCR amplicon length heterogeneity Suzuki M, Rappe MS, Giovannoni SJ. Marine bacterioplankton diversity was examined by quantifying natural length variation in the 5' domain of small-subunit (SSU) rRNA genes (rDNA) amplified by PCR from a DNA sample from the Oregon coast . This new technique, length heterogeneity analysis by PCR (LH-PCR), determines the relative proportions of amplicons originating from different organisms by measuring the fluorescence emission of a labeled primer used in the amplification reaction . Relationships between the sizes of amplicons and gene phylogeny were predicted by an analysis of 366 SSU rDNA sequences from cultivated marine bacteria and from bacterial genes cloned directly from environmental samples . LH-PCR was used to compare the distribution of bacterioplankton SSU rDNAs from a coastal water sample with that of an SSU rDNA clone library prepared from the same sample and also to examine the distribution of genes in the PCR products from which the clone library was prepared . The analysis revealed that the relative frequencies of genes amplified from natural communities are highly reproducible for replicate sets of PCRs but that a bias possibly caused by the reannealing kinetics of product molecules can skew gene frequencies when PCR product concentrations exceed threshold values. Gastroenterology, 1998 Nov, 115(5), 1113 - 22 Lack of correlation between Lewis antigen expression by Helicobacter pylori and gastric epithelial cells in infected patients; Taylor DE et al.; BACKGROUND & AIMS: Lewis antigens are expressed by both human gastric epithelial tissue and Helicobacter pylori . We examined Lewis antigens expressed by gastric epithelium and by H . pylori isolated from the corresponding biopsy tissue . METHODS: H . pylori Lewis expression was determined by enzyme immunoassays, and immunoelectron microscopy was used to confirm the Lewis antigens on some H . pylori cells and in some biopsy specimens . Histopathology using identical monoclonal antibodies specific for Lewis A, B, X, and Y antigens was used to detect these antigens in 24 gastric biopsy specimens . RESULTS: We identified Lewis Y in 100%, Lewis X and Lewis B in 95.8%, and Lewis A in 87.5% of biopsy specimens . In H . pylori, 87.5% expressed Lewis Y, 79.2% Lewis X, and 4.2% (one strain) Lewis B . No Lewis A was detected . Antibody specific for Lewis X labeled the bacteria and associated adhesion pedestal . The cagA gene was present in 92% of strains . CONCLUSIONS: There was no direct relationship between Lewis antigen expression by H . pylori and gastric epithelial cells in infected patients . Expression of Lewis X and Lewis Y by H . pylori suggests the possibility of their requirement for establishment and/or maintenance of infection . An immunoelectron micrograph of H . pylori interaction with the gastric epithelial adhesion pedestal suggests a tentative role for Lewis X in the adhesion process. Appl Environ Microbiol, 1998 Nov, 64(11), 4246 - 54 PCR-ribotyping of Xenorhabdus and Photorhabdus isolates from the Caribbean region in relation to the taxonomy and geographic distribution of their nematode hosts; Fischer-Le Saux M et al.; The genetic diversity of symbiotic Xenorhabdus and Photorhabdus bacteria associated with entomopathogenic nematodes was examined by a restriction fragment length polymorphism analysis of PCR-amplified 16S rRNA genes (rDNAs) . A total of 117 strains were studied, most of which were isolated from the Caribbean basin after an exhaustive soil sampling . The collection consisted of 77 isolates recovered from entomopathogenic nematodes in 14 Caribbean islands and of 40 reference strains belonging to Xenorhabdus and Photorhabdus spp . collected at various localities worldwide . Thirty distinctive 16S rDNA genotypes were identified, and cluster analysis was used to distinguish the genus Xenorhabdus from the genus Photorhabdus . The genus Xenorhabdus appears more diverse than the genus Photorhabdus, and for both genera the bacterial genotype diversity is in congruence with the host-nematode taxonomy . The occurrence of symbiotic bacterial genotypes was related to the ecological distribution of host nematodes. Antimicrob Agents Chemother, 1998 Nov, 42(11), 2923 - 31 The Epstein-Barr virus thymidine kinase does not phosphorylate ganciclovir or acyclovir and demonstrates a narrow substrate specificity compared to the herpes simplex virus type 1 thymidine kinase; Gustafson EA et al.; The Epstein-Barr virus (EBV) thymidine kinase (TK) was expressed in mammalian 143B TK- cells to investigate its substrate specificity . The herpes simplex virus type 1 (HSV-1) TK was similarly expressed for comparison . Both viral TKs conferred a TK+ phenotype on 143B TK- cells . The nucleoside analog ganciclovir (GCV) did not affect the growth of 143B EBV TK or 143B TK- cells but effectively killed 143B HSV-1 TK cells . Furthermore, lysates of 143B EBV TK cells could not phosphorylate GCV, which was confirmed by high-performance liquid chromatography . EBV TK, HSV-1 TK, and EBV TK N-, a truncated EBV TK missing 243 N-terminal amino acids, were purified as fusion proteins expressed in bacteria, and all had TK activity . In addition, EBV TK was observed to have a thymidylate kinase activity but could not phosphorylate GCV, acyclovir, or 2'-deoxycytidine . In competition assays, only nucleoside analogs of thymidine significantly inhibited thymidine phosphorylation by EBV TK, with the following rank order: 5-bromodeoxyuridine > zidovudine > stavudine > sorivudine . These results demonstrate that EBV TK substrate specificity is narrower than those of alphaherpesvirus TKs and that thymidine analogs may be the most suitable nucleoside antivirals to target the enzyme . Clinical implications for gammaherpesviruses are discussed. Acta Gastroenterol Belg, 1998 Jul-Sep, 61(3), 350 - 1 Adverse events of HP eradication: long-term negative consequences of HP eradication; Koster ED; Two problems can be identified as possible long term negative consequences of HP eradication: diminished efficacy of acid-lowering drugs, and an accelerated development of GERD . It was shown that omeprazole produces a greater decrease in gastric acidity in subjects with H . pylori infection than in those who are H . pylori negative, and that omeprazole produces a smaller decrease in gastric acidity after cure of H . pylori . This effect persisted for at least one year after HP eradication . It is not limited to omeprazole, but can also be seen with the H2 receptor antagonist ranitidine . At least one proven mechanism involved in this phenomenon is the disappearance of the alkalinizing effect of ammonia, generated from urea by HP's urease, after eradication of the bacteria; other mechanisms may also be involved . HP eradication may therefore potentially hamper acid inhibitory treatment . It is unknown to what extent this is clinically relevant . Although one study did not observe a relation between H . pylori status and efficacy of omeprazole maintenance therapy for GERD, it cannot be excluded that some patients may need more potent or higher doses of acid-lowering medication after HP eradication . Three studies suggest that duodenal ulcer patients who were successfully treated with H . pylori eradication therapy, may be at increased risk to develop GERD . Labenz's study finds that the incidence of GERD may be double 3 years after eradication . The life-table analysis suggested that cure of the infection was associated with an increased risk of reflux oesophagitis during the first year after treatment, whereas later the incidence of reflux oesophagitis was similar in both groups . Patients who developed reflux oesophagitis after the cure had a more severe body gastritis before cure, gained weight more frequently after cure, and were predominantly men . There are no data on the fate of the oesophagus after HP eradication in patients with reflux oesophagitis . The data thus strongly suggest that there is a risk for developing reflux oesophagitis after HP eradication in patients with duodenal ulcer . It is unknown whether HP eradication in patients without duodenal ulcer also increases the risk for developing reflux oesophagitis. Biochim Biophys Acta, 1998 Oct 23, 1425(2), 437 - 40 Cloning, characterization and expression of beta-N-acetylglucosaminidase gene from Streptomyces thermoviolaceus OPC-520(1); Tsujibo H et al.; The nagB gene encoding beta-N-acetylglucosaminidase from S . thermoviolaceus OPC-520 was cloned and sequenced . The nagB gene could encode a protein of 541 amino acids with a calculated molecular mass of 58274 . NagB revealed significant similarities to beta-N-acetylhexosaminidases and chitobiases from bacteria, which are classified into family 20 glycosyl hydrolases . NagB effectively hydrolyzed all of the chitin oligosaccharides from dimer to hexamer. Arch Pharm (Weinheim), 1998 Sep, 331(9), 269 - 72 Synthesis and biological evaluation of a series of substituted pyrazolo{3,4-d}-1,2,3-triazoles and pyrazolo{3,4-d}oxazoles; Vicentini CB et al.; In view of the biological relevance of triazole-based heterocyclic structures as antifungal, antiviral, and antitumor agents, we have synthesized a series of substituted pyrazolo{3,4-d}-1,2,3-triazoles (2e-h, 2j, 4b) which we evaluated for their cytostatic and antiviral (HIV-1 included) activity and for their capability to inhibit the multiplication of various human pathogenic fungi and bacteria . Moreover, the biological activities of a few compounds, namely pyrazolo{3,4-d}oxazoles (3a-e) and pyrazolo{3,4-d}-1,2,3-triazoles (2a-d, 4a, 5), previously obtained by us but not investigated for their biological activity, were also studied . Only compounds 3a-e were endowed with a significative antiproliferative activity on the human lymphoblastoid cell line MT-4 cells . All pyrazole derivatives proved ineffective in protecting cell cultures against the HIV-1-induced cytopathogenicity, and none of the compounds was active against the bacteria and fungi tested. J Biochem (Tokyo), 1998 Nov, 124(5), 869 - 75 Emerging roles of Dlg-like PDZ proteins in the organization of the NMDA-type glutamatergic synapse; Nagano T et al.; A group of proteins found at cell-cell junctions have a common structural domain, called PDZ-a stretch of 80-90 amino acid residues initially identified in the three proteins PSD-95, Dlg, and ZO-1 . This domain is found in various proteins from bacteria to mammals and is involved in protein-protein interaction . Recently, many proteins containing this domain were identified in the nervous system by molecular cloning and shown to interact with other synaptic proteins, including various transmitter receptors, ion channels, and signal transducers . These PDZ-containing proteins are mostly located near the synaptic membrane and are, therefore, speculated to transport associated proteins to the synapse and/or anchor them at the synaptic sites . Alternatively, as a single molecule often contains multiple PDZ domains that can interact with each other, it may cluster all these synaptic molecules and facilitate their signaling at synaptic sites . This review focuses on the best characterized PDZ-containing proteins that interact with N-methyl-D-aspartate (NMDA)-type glutamate receptors and discusses their functions in synaptic organization. Histochem J, 1998 Aug, 30(8), 549 - 52 The modified Steiner stain: a new use for an old stain? Staining cytomegalovirus-infected cells in gastrointestinal biopsies; Saiz E et al.; The modified Steiner stain is a non-specific silver stain for identifying bacteria in formalin-fixed, paraffin-embedded tissues . The principle behind its use is that bacteria are first sensitized using uranyl nitrate solution, making them able to precipitate silver from a silver nitrate solution . It is used routinely for staining gastric biopsies to identify Helicobacter pylori . Upon staining a gastric biopsy from a patient with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus gastritis, we recognized that this technique also stains the viral inclusions of cytomegalovirus-infected cells . We then proceeded to stain 43 consecutive cytomegalovirus-positive gastrointestinal biopsies from 33 immunocompromised patients based on positive cytomegalovirus immunohistochemistry (DAKO-cytomegalovirus monoclonal antibody, clones DDG9 and CCH2) . We also stained eight cytomegalovirus-infected, non-gastrointestinal tissues, including lung, adrenal gland, ovary, skin and neural tissue, to ensure that the stain was staining the cytomegalovirus-infected cells and not argyrophilic or argentaffin neuroendocrine cells of the gastrointestinal tract . In 40 of the 43 cytomegalovirus-infected gastrointestinal biopsies, we saw positive staining with the modified Steiner stain (93% sensitivity) . The cytomegalovirus-infected, non-gastrointestinal tissues all stained positively with the modified Steiner stain . Because the modified Steiner stain is frequently used to identify Helicobacter pylori in gastric biopsies, we propose that it be studied further for possible use either as a screen or as a confirmatory tool, or both, for cytomegalovirus inclusions in gastrointestinal biopsies. Eur Heart J, 1998 Sep, 19(9), 1321 - 7 The prevalence of chronic Chlamydia pneumoniae infection as detected by polymerase chain reaction in pharyngeal samples from patients with ischaemic heart disease; Gabriel AS et al.; AIMS: Cross-sectional serological studies have suggested an association between ischaemic heart disease and infections from Chlamydia pneumoniae and Helicobacter pylori . We therefore sought to find out if patients with ischaemic heart disease had an increased prevalence of C . pneumoniae in the pharynx . As the course of the C . pneumoniae infection remains unclear, both acute and follow-up samples were taken and compared with antibody levels . METHODS AND RESULTS: We studied 282 patients with ischaemic heart disease . One hundred and two subjects without history or symptoms of ischaemic heart disease served as controls . Pharyngeal specimens for polymerase chain reaction detection of C . pneumoniae, and blood samples for C . pneumoniae and H . pylori antibody detection, were collected . In patients with positive polymerase chain reaction or C . pneumoniae IgA titres > or = 32, indicating current infection, convalescent samples were taken at least 6 weeks later . An immunofluorescent antigen detection test was used to confirm the presence of C . pneumoniae elementary bodies in specimens found to be polymerase chain reaction positive . The prevalence of positive polymerase chain reaction tests was 36% among patients and 22% among controls (P<0.05) . Forty-seven percent of patients with positive polymerase chain reaction remained positive in the convalescent test . Elevated C . pneumoniae IgG titres > or = 512 were found in 39% of patients and 26% of the controls (P<0.05) . IgA titres > or = 32 were found in 46% of the patients and 44% of the controls (ns) . Antibody titres remained largely unchanged at convalescent testing . Two patients and none of the controls had IgM titres > 16 . There was no link between positive H . pylori serology and positive C . pneumoniae polymerase chain reaction tests . CONCLUSIONS: The high prevalence and persistence of positive pharyngeal C . pneumoniae polymerase chain reaction and elevated antibody titres in patients with ischaemic heart disease indicate a chronic infection . The pharyngeal presence of C . pneumoniae might contribute to a low grade inflammatory activation or be a source for further spread of the bacteria to atherosclerotic vessels. Toxicon, 1998 Nov, 36(11), 1683 - 92 From noxiustoxin to Shiva-3, a peptide toxic to the sporogonic development of Plasmodium berghei; Possani LD et al.; This communication reviews shortly the main structural and functional characteristics of Noxiustoxin, a 39 amino acid residue peptide, maintained closely packed by three-disulfide bridges and its effects on excitable membranes . Shiva-3, a cecropin like-peptide composed of 38 amino acid residues is also briefly reviewed . Its design and synthesis was made possible by the expertise gained through the work previously performed with Noxiustoxin . One of the most prominent functional characteristics of Shiva-3 is the toxic effect upon the sporogonic development of Plasmodium berghei (responsible for a murine version of malaria) . A synthetic Shiva-3 gene was constructed by recursive polymerase-chain reaction (PCR) methodology and expressed using the vector pGEX2T as a hybrid protein between the glutathione-S-transferase at the N-terminal and Shiva-3 in the C-terminal part of the hybrid . The recombinant protein kills bacteria and Plasmodium berghei . The future aim of this work is to produce a transgenic mosquito that carries the message for synthesis and excretion of Shiva-3 and similar peptides, in the midgut of mosquitoes, in an attempt to control the spreading of human malaria. J Bacteriol, 1998 Nov, 180(21), 5567 - 73 Identification and recombinant expression of a Mycobacterium avium rhamnosyltransferase gene (rtfA) involved in glycopeptidolipid biosynthesis; Eckstein TM et al.; The Mycobacterium avium complex is a source of disseminated infections in patients with advanced AIDS . This group of mycobacteria is distinguished by the presence of highly antigenic, surface-exposed glycopeptidolipids, and these glycolipids possess variant oligosaccharide structures that are the chemical basis of the 28 distinct serovars of the M . avium complex . We previously described the ser2 gene cluster, encoding the synthesis of the haptenic oligosaccharide (2, 3-dimethylfucose-rhamnose-6-deoxytalose-) of the serovar 2-specific glycopeptidolipid, and revealed a locus (ser2A) encoding a putative rhamnosyltransferase . Sequencing of the ser2A locus demonstrated the presence of three open reading frames, two of which yielded significant homology to several glycosyltransferases, and the deduced amino acid sequences of these two putative glycosyltransferases had 63% identity . These two genes were expressed in Mycobacterium smegmatis, and the resulting recombinant glycopeptidolipids were characterized by thin-layer chromatography and gas chromatography-mass spectrometry . These analyses demonstrated that only one of these genes, termed rtfA, encoded the rhamnosyltransferase responsible for the transfer of rhamnose to 6-deoxytalose . The identification of rtfA will permit further evaluation of glycopeptidolipid biosynthesis and the construction of isogenic mutants of multiple M . avium complex serovars . Moreover, such mutants will help define the role of glycopeptidolipids in the intracellular survival of these bacteria. Biochem Biophys Res Commun, 1998 Oct 29, 251(3), 920 - 5 Molecular cloning of rat klotho cDNA: markedly decreased expression of klotho by acute inflammatory stress; Ohyama Y et al.; We have recently identified a novel gene, termed klotho, that is involved in the suppression of several aging phenotypes . The gene encodes a membrane protein that shares sequence similarity with the beta-glucosidases of bacteria and plants . In this study, we isolated rat klotho cDNA and examined its tissue distribution in rats . The deduced amino acid sequence of rat Klotho protein was 1014 amino acids in length and 94 and 85% homologous to those of mouse and human Klotho proteins, respectively . Northern blot analysis using the rat klotho cDNA probe identified a single transcript of 5.2 kb in size expressed predominantly in the kidney, while RT-PCR detected low levels of expression also in the brain, lung, intestine, and ovaries . During development, klotho expression in the kidney was markedly augmented after birth . Chromosomal localization of rat klotho was mapped to 12q12 . Northern blot analysis showed that expression of klotho was markedly decreased by lipopolysaccharide (LPS) in vivo, suggesting that expression of klotho is affected by acute inflammatory stress . The present study leads to a better understanding of the physiologic and pathophysiologic roles of Klotho . Microb Pathog, 1998 Sep, 25(3), 157 - 64 Outer membrane proteins of Bartonella henselae and their interaction with human endothelial cells; Burgess AW et al.; Members of the genus Bartonella are unique in that they are bacteria which cause proliferation of microvascular endothelial cells and neovascularization (angiogenesis) . The mechanisms by which Bartonella henselae causes these processes are unknown . Given the importance of surface-exposed determinants in the pathogenesis of many organisms, outer membrane proteins (OMPs) of B . henselae were identified . Enrichment of the outer membrane fraction of B . henselae by sarkosyl treatment of total membranes, together with radioiodination and biotinylation of intact organisms, suggest that at least nine proteins, with molecular weights of 28, 30, 35, 43, 58, 61, 79, 92 and 171 kDa, are located in the outer membrane . Triton X-100-extracted biotinylated human umbilical vein endothelial cell (HUVEC) surface proteins bound to the 43 kDa B . henselae OMP after B . henselae whole-cell lysates and sarkosyl-fractionated OMPs were separated by SDS-PAGE and transferred onto nylon . Biotinylated B . henselae surface proteins of 28, 32, 43, 52 and 58 kDa were shown to bind intact HUVEC, with the 43 kDa protein being the major adhesin . Preincubation of HUVEC with an increasing concentration (20 microg/ml to 4 mg/ml) of sarkosyl-fractionated unlabelled B . henselae outer membrane proteins inhibited the attachment of all identified HUVEC binding proteins . The identification of B . henselae OMPs, as well as adhesins, should provide a basis for further investigation of the role of adherence in the pathogenesis of B . henselae . Environ Health Perspect, 1998 Oct, 106 Suppl 5, 1157 - 63 Contribution of reactive oxygen and nitrogen species to particulate-induced lung injury; Zhu S et al.; Recently, a second pathway for the generation of potential oxidants with the reactivity of the hydroxyl radical without the need for metal catalysis has been described . In response to various inflammatory stimuli, lung endothelial, alveolar, and airway epithelial cells, as well as activated alveolar macrophages, produce both nitric oxide (.NO) and superoxide anion radicals (O2.-) . .NO regulates pulmonary vascular and airway tone and plays an important role in lung host defense against various bacteria . However, .NO may be cytotoxic by inhibiting critical enzymes such as mitochondrial aconitase and ribonucleotide reductase, by S-nitrosolation of thiol groups, or by binding to their iron-sulfur centers . In addition, .NO reacts with O2.- at a near diffusion-limited rate to form the strong oxidant peroxynitrite (ONOO-), which can nitrate and oxidize key amino acids in various lung proteins such as surfactant protein A, and inhibit their functions . The presence of ONOO- in the lungs of patients with acute respiratory distress syndrome has been demonstrated by measuring levels of nitrotyrosine, the stable product of tyrosine nitration . Various studies have shown that inhalation or intratracheal instillation of various respirable mineral dusts or asbestos fibers increased levels of inducible nitric oxide synthase mRNA . In this presentation, we review the evidence for the upregulation of .NO in the lungs of animals exposed to mineral particulates and assess the contribution of reactive nitrogen species in the pathogenesis of the resultant lung injury. Mol Gen Genet, 1998 Sep, 259(5), 491 - 503 The pea (Pisum sativum L.) genes sym33 and sym40 control infection thread formation and root nodule function; Tsyganov VE et al.; Two novel non-allelic mutants that were unable to fix nitrogen (Fix ) were obtained after EMS (ethyl methyl sulfonate) mutagenesis of pea (Pisum sativum L.) . Both mutants, SGEFix(-)-1) and SGEFix(-)-2, form two types of nodules: SGEFix(-)-1 forms numerous white and some pink nodules, while mutant SGEFix(-)-2 forms white nodules with a dark pit at the distal end and also some pinkish nodules . Both mutations are monogenic and recessive . In both lines the manifestation of the mutant phenotype is associated with the root genotype . White nodules of SGEFix(-)-1 are characterised by hypertrophied infection threads and infection droplets, mass endocytosis of bacteria, abnormal morphological differentiation of bacteroids, and premature degradation of nodule symbiotic structures . The structure of the pink nodules of SGEFix(-)-1 does not differ from that of the parental line, SGE . White nodules of SGEFix(-)-2 are characterised by "locked" infection threads surrounded with abnormally thick plant cell walls . In these nodules there is no endocytosis of bacteria into host-cell cytoplasm . The pinkish nodules of SGEFix(-)-2 are characterised by virtually undifferentiated bacteroids and premature degradation of nodule tissues . Thus, the novel pea symbiotic genes, synm40 and sym33, identified after complementation analysis in SGEFix(-)-1 and SGEFix(-)-2 lines, respectively, control early nodule developmental stages connected with infection thread formation and function. Mol Gen Genet, 1998 Sep, 259(5), 475 - 83 StgR, a new Streptomyces alboniger member of the LysR family of transcriptional regulators; Tercero JA et al.; A 3240-bp DNA fragment, located next to the puromycin biosynthetic gene cluster of Streptomyces alboniger, contains three complete ORFs in the order: stgA, stgU and stgR . The transcriptional orientation of stgA is opposite to that of stgU and stgR . Each gene is expressed from its own promoter, although stgU and stgR can be cotranscribed . The deduced amino acid sequences of their products present similarities to a variety of pyridoxal-phosphate-dependent aspartate aminotransferases (StgA), several proteins of unknown function (StgU), and the LysR-type of transcriptional regulators (StgR) . In a delta stgR null mutant of S . alboniger, transcription of stgA and stgU is increased with respect to that in the wild type . In addition, in vivo experiments with promoter-probe plasmids indicated that in the delta stgR mutant, stgA- or stgU-promoter-dependent expression of the reporter gene was up to three-fold higher than in the wild type . Taken together, these results indicate that StgR is a LysR-type transcriptional repressor of both stgA and stgU. Dis Aquat Organ, 1998 Sep 11, 34(1), 21 - 6 Performance of serum-free broth media for growth of Renibacterium salmoninarum; Starliper CE et al.; Growth of Renibacterium salmoninarum was compared in 14 different broth media; 13 serum-free, and 1 that contained newborn calf serum, KDM2+M . Supplementation with 1% v/v R . salmoninarum MCO4M metabolite was evaluated for 6 of the media that do not utilize it as part of their ingredients . Viable cells were enumerated on Days 10, 20, and 30 post inoculation to evaluate performance . The experiment was repeated 3 times using high, low, and medium (trials 1 to 3, respectively) cell concentrations as inoculum . In general there was no optimal medium and all performed well . The choice of which to employ depends on the ease of preparation and presence of certain ingredients that might affect subsequent assays . In trials 2 and 3, the pH was estimated using test papers at the same time as cells were counted . Maximum pH increase occurred with KDM2+M and those media containing charcoal . For most media, a simple pH determination could be used as a means to check that growth has occurred in a culture, particularly if charcoal was added directly to the media and a visual inspection could not be made to detect growth. Acta Physiol Scand Suppl, 1998 Aug, 643, 257 - 64 Structure and function of the Na+/glucose cotransporter; Wright EM et al.; Cotransporters are a major class of membrane transport proteins that are responsible for the accumulation of nutrients, neurotransmitters, osmolytes and ions in cells from bacteria to man . The energy for solute accumulation comes from the proton and/or sodium electrochemical gradients that exist across cell membranes . A major problem in biology is how transport is coupled to these electrochemical potential gradients . The primary example of this class of membrane proteins is the intestinal brush border Na+/glucose cotransporter (SGLT1), first described by Bob Crane in 1960 . Over 35 members of the SGLT1 gene family have been identified in animal cells, yeast and bacteria, and all share a common core structure of 13 transmembrane (TM) helices . Electrophysiological techniques have been used to examine the function of several family members, chimeras and mutants expressed in heterologous systems such as Xenopus laevis oocytes . These have revealed that cotransporters are multi-functional proteins: they are responsible for 1) . uncoupled passive Na+ transport (Na+ uniport); 2) . down-hill water transport in the absence of substrate; 3) . Na+/substrate cotransport; and 4) . Na+/substrate/water cotransport . The sugar binding and translocation pathway is formed by 4 TM helices near the C-terminal of the protein, helices 10-13 . We propose that the N-terminal domains of SGLT1 are responsible for Na+ binding and/or translocation, and that Na+/glucose cotransport results from interactions between the N- and C-terminal domains of the protein. Zentralbl Hyg Umweltmed, 1998 Sep, 201(3), 279 - 84 Persistence of infectious hepatitis A virus and its genome in artificial seawater; Arnal C et al.; The stability of the hepatitis A virus (HAV) genome detectable by RT-PCR in artificial sterile seawater seeded with HAV has been compared to that of HAV detectable in cell culture . The HAV genome was detectable by RT-PCR for 232 days while virus particles were detectable in cell culture for only 35 days . This difference in stability indicates that detection of the HAV genome by RT-PCR is not a reliable indicator of the survival of HAV detectable in cell cultures . However, before these results can be extrapolated to stability in natural seawater, the effect of additional elements in the natural environment, such as bacteria, fungi and suspended matter, on the stability of the HAV genome and cell culture infectious HAV particles, will have to be examined. Toxicol Lett, 1998 Sep 15, 98(3), 147 - 53 Genotoxicity of the dust organic extract and its fractions derived from an aluminium electrolytic plant; Yumei W et al.; The dust derived from an aluminium electrolytic plant was collected on a filter, then extracted by mixed solvent of benzene, hexane and isopropanol (7/2/1, v/v) . The solvent-soluble components was separated into five fractions, namely organic acids, organic alkalis, aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and polar compounds . The genotoxicities of the dust organic extract and its five fractions were examined with Ames test, unscheduled DNA synthesis (UDS), micronucleus (MN) and sister-chromatid exchange (SCE) tests in human lymphocytes in vitro which involve the different test systems (bacteria and mammalian cells) and three genetic endpoints (gene mutation, chromosome aberration and DNA damage) . The results of four experiments indicated that the dust organic extract showed higher genotoxicity . Among the five fractions, three fractions, namely organic acids, polycyclic aromatic hydrocarbons and polar compounds had higher genotoxicity than others . The other fractions, organic alkalis and aliphatic hydrocarbons had no genotoxicity . According to this study, it is necessary to take effective measures to abate the dust and protect the environment and human health. Dis Colon Rectum, 1998 Oct, 41(10), 1273 - 80 Effect of bowel preparation and a fiber-free liquid diet on expression of transforming growth factor and procollagen in colonic tissue preoperatively and postoperatively; Buckmire M et al.; PURPOSE: Dehiscence of colonic anastomoses is prevalent and potentially fatal . In an attempt to reduce the likelihood of anastomotic dehiscence, the colon is cleansed before surgery and fiber-free diets are prescribed postoperatively . However, fiber-free diets induce colonic atrophy and impair healing . This study was designed to investigate the effect of bowel preparation and postoperative fiber-free diet on the local gene expression of transforming growth factor-beta 1 and procollagen type I . METHODS: Four Sprague-Dawley rats underwent bowel preparation with a fiber-free liquid diet and polyethylene glycol in a balanced electrolyte solution for two days (fiber-free preoperative diet group), whereas four rats received standard chow with fiber (preoperative diet with fiber group) . On the third day tissue was obtained from the descending colon of each rat to assess the effect of bowel preparation . Forty additional rats had their bowels prepared and underwent transection of the descending colon and anastomosis . These rats were then randomly assigned to continue on the liquid diet (fiber-free postoperative diet group) or rat chow (postoperative diet with fiber group) . On postoperative days 3, 5, 6, 7, and 14, colonic tissue was obtained from the anastomosis and analyzed with the use of semiquantitative reverse transcriptase-polymerase chain reaction to examine the relative expression of transforming growth factor-beta 1 and procollagen type I genes normalized to that of a constitutive gene . RESULTS: There was a decrease in the expression of the transforming growth factor-beta 1 and the procollagen type I genes in the fiber-free preoperative diet group compared with the preoperative diet with fiber group; however, this difference only reached statistical significance for procollagen type I . Postoperatively, significant increases in the expression of the transforming growth factor-beta 1 and procollagen type I genes over baseline levels were observed around postoperative day 7 in both groups, which temporally correlates with active phases of collagen deposition in the wounded colon . Expression of the procollagen type I gene, however, was significantly decreased at this time in the fiber-free postoperative diet group compared with the postoperative diet with fiber group . CONCLUSION: Although necessary to reduce septic complications, preoperative bowel preparation has a detrimental effect on the expression of transforming growth factor-beta 1 and procollagen type I . A postoperative fiber-free liquid diet also may be detrimental to the expression of these transcripts in the bowel . Alternative methods for delivery of colonic fuels are needed to create a better environment for colonic healing while eliminating bacteria and bulk. Nat Biotechnol, 1998 Oct, 16(10), 925 - 8 Development of transgenic yellow poplar for mercury phytoremediation; Rugh CL et al.; We examined the ability of yellow poplar (Liriodendron tulipifera) tissue cultures and plantlets to express modified mercuric reductase (merA) gene constructs . Mercury-resistant bacteria express merA to convert highly toxic, ionic mercury, Hg(II), to much less toxic, elemental mercury, Hg(O) . Expression of merA in transgenic plants might provide an ecologically compatible approach for the remediation of mercury pollution . Because the alteration of the bacterial merA gene sequence is necessary for high-level expression in Arabidopsis thaliana, yellow poplar proembryogenic masses (PEMs) were transformed with three modified merA constructs via microprojectile bombardment . Each construct was synthesized to have altered flanking regions with increasing amounts of modified coding sequence . All merA constructs conferred resistance to toxic, ionic mercury in independently transformed PEM colonies . Stability of merA transgene expression increased in parallel with the extent of gene coding sequence modification . Regenerated plantlets containing the most modified merA gene (merA18) germinated and grew vigorously in media containing normally toxic levels of ionic mercury . The merA18 plantlets released elemental mercury at approximately 10 times the rate of untransformed plantlets . These results indicate that plants expressing modified merA constructs may provide a means for the phytoremediation of mercury pollution. Biospectroscopy, 1998, 4(5), 311 - 26 Orientation of the heme vinyl groups in the hydrogen sulfide-binding hemoglobin I from Lucina pectinata; Silfa E et al.; Hemoglobin I (HbI) from the claim Lucina pectinata is a unique heme protein that binds and transfers hydrogen sulfide (H2S) to a symbiotic bacteria . The metcyano, metaquo, carbon monoxy, oxy, and deoxy complexes of HbI were studies by resonance Raman (RR) spectroscopy, and the metacyano and carbon monoxy complexes were also studied by 1H-NMR . The results indicate a unique orientation of the heme 2-vinyl group relative to other heme proteins . The RR spectra of the HbICO, metHbICN, metHbIH2O, HbIO2 and deoxyHbI heme derivatives show a band at 1621 cm-1 and a shoulder at 1626 cm-1, indicative of an out-of-plane position for one of the vinyls relative to the other one . Spin-lattice relaxation properties of protons in the metHbICN complex also suggest a unique orientation for the heme 2-vinyl group of HbI . The longitudinal relaxation time (T1) for the 2-H alpha, 2-H beta c, and H beta t protons are 120 ms, 115 ms, and 135 ms, respectively . The data from both techniques suggest an out-of-plane and trans-oriented 2-vinyl group, and an in-plane and cis-oriented 4-vinyl group for the low-spin complexes of HbI . These results imply that the electron withdrawing character of the out-of-plane vinyl group contributes to the stability of the heme Fe+3 oxidation state, facilitates the binding of the H2S ligand, and promotes the stability of this ferric H2S complex. Comp Biochem Physiol B Biochem Mol Biol, 1998 May, 120(1), 205 - 16 Pyruvate dehydrogenase E1 alpha isoform in rat testis: cDNA cloning, characterization, and biochemical comparison of the recombinant testis and liver enzymes; Jeng J et al.; Previous data indicated a tissue-specific regulation of mitochondrial pyruvate dehydrogenase (PDH) complex, especially in the brain and testis . The lack of biochemical data on the rat testis PDH limits comparative analysis between testis and liver enzymes . Therefore, we have isolated a cDNA clone encoding rat testis PDH E1 alpha isoform, determined its nucleotide sequence, studied the tissue-specific expression, and characterized the recombinant protein produced in bacteria, compared to the liver counterpart . Our cDNA clone (2.2 kb) contained the identical open reading frame (from nt 974 to 2149) with that previously reported (Cullingford et al., 1993 Biochim Biophys Acta 1216:149-153) but contained a long 5' untranslated region, which has little identity to the other clone . Northern blot confirmed testis-specific expression of this isoform . Genomic DNA analyses by PCR amplification suggested this clone is a gene product distinct from its X-linked somatic counterpart . Our biochemical and kinetic analyses revealed that the purified recombinant rat testis PDH E1 (containing both E1 alpha and E1 beta subunits) was enzymatically active and phosphorylated in vitro by purified PDH-kinase p48 or p45, similar to the recombinant human liver enzyme . Our current data thus indicate that the differential regulation of testis PDH observed in the animal model may result from differential modulation of PDH-kinase or -phosphatase in this tissue rather than the presence of functionally different PDH E1 subunit. Stress, 1997 May, 1(3), 123 - 134 Mini-Review; Stress Genes: An Introductory Overview; Macario AJ et al.; Molecular sequence data, made available in the last 15 years or so, have led to the classification of living cells into three phylogenetic domains: Bacteria, Archaea, and Eucarya . All the organisms that have been tested belonging to either domain were capable of mounting a stress response with essentially the same characteristics, regardless of the stressor . The protagonists in the cell's stress response are the stress genes and their protein products . Some of the latter are molecular chaperones . Under physiological conditions, these chaperones aid other cellular proteins to fold properly and achieve a native -functional- configuration, and to translocate from the place of synthesis to the cell's locale in which they will operate . In a stressed cell, the stress proteins that are chaperones protect other molecules from denaturation and help those partially damaged to regain a functional configuration . Thus, cell death is avoided and recovery is enhanced . The study of stress genes and proteins has progressed considerably in organisms belonging to the domains Bacteria and Eucarya . Less is known about the archaeal stress genes . Here, research with an organism from the Archaea is discussed, focusing on the stress genes of the hsp70 (dnaK) locus . Future perspectives for basic and applied research within the health sciences and biotechnology industries are presented. Eur J Oral Sci, 1998 Oct, 106(5), 938 - 44 Adherence of Porphyromonas gingivalis to epithelial cells: analysis by flow cytometry; Huard-Delcourt A et al.; Porphyromonas gingivalis, implicated in the pathogenesis of periodontitis, can adhere to epithelial cells and gingival fibroblasts . This study employed flow cytometry to evaluate the adherence of P . gingivalis to epithelial cells under various conditions . The cell lines SK-MES and KB were used in the first experiments . The P . gingivalis strains employed were ATCC 33277, ATCC 49417 and W83 . Different adherence conditions were tested (contact time, bacteria/cell ratio, contact temperature) . In later experiments, adherence of P . gingivalis to human gingival epithelial cells (GEC) obtained by explant was studied under various conditions . Results showed that P . gingivalis had a high affinity for buccal keratinocytes compared with SK-MES . Adherence showed a level of saturation . The number of receptors may be limited for each epithelial cell line, and there may be more receptors for gingival keratinocytes . Depending on contact time, P . gingivalis showed a higher affinity for GEC, compared with the other two lines . P . gingivalis thus showed specific adherence for a host cell type from a site associated with periodontal disease. Mol Microbiol, 1998 Oct, 30(1), 197 - 208 Intracellular multiplication and human macrophage killing by Legionella pneumophila are inhibited by conjugal components of IncQ plasmid RSF1010; Segal G et al.; Previously we have reported that Legionella pneumophila can mediate plasmid DNA transfer at a frequency of about 10(-3) transconjugants per donor and that this process is dependent on several icm genes . Here we characterize the icm-dependent conjugal ability of L . pneumophila and study its relationship to intracellular multiplication and host cell killing . We found that three icm genes and the RSF1010 mobA gene are completely required and that three icm genes and the RSF1010 mobC gene are partially required for conjugation . Conjugation occurred during lag phase and stopped when the cell number increased . Inhibition of transcription or translation in the donor had only a minor effect on conjugation frequency . These results suggest that stationary-phase bacteria contain a functional icm complex that can mediate conjugal DNA transfer and probably can initiate infection of human macrophages as well . We also found that a functional RSF1010 mobilization system inhibits intracellular multiplication and killing of human macrophages by L . pneumophila . The strongest inhibition was observed in icm insertion mutants complemented with wild-type icm genes on an RSF1010-derived plasmid . These results suggest that the conjugation substrate probably competes with the natural substrate of the L . pneumophila icm system for transfer outside the bacterial cell . We propose that the function of the L . pneumophila icm system is to transfer effector molecules to the host cell . These effector molecules may interact with components of the host cell that are involved in phagosome formation and fate. Mol Microbiol, 1998 Oct, 30(1), 107 - 19 An essential GTP-binding protein functions as a regulator for differentiation in Streptomyces coelicolor; Okamoto S et al.; The Streptomyces coelicolor obg gene, which encodes a putative GTP-binding protein of the Obg/Gtp1 family, was characterized . The obg gene was essential for viability . Introduction of multiple copies of obg into wild-type S . coelicolor suppressed aerial mycelium formation . A single amino acid substitution at any of six positions was introduced into the GTP binding site of Obg, and the mutated proteins were expressed in wild-type cells . Obg(P168-->V) exerted a more accentuated suppressive effect on aerial mycelium formation than did the wild-type Obg protein . In contrast, Obg(G171-->A) accelerated the development of aerial mycelium . These results show that Obg protein functions as a pivotal regulator for the onset of cell differentiation through its ability to bind GTP . Western analysis revealed that expression of obg is regulated in a growth phase-dependent manner, indicating a sharp decrease just after onset of aerial mycelium development or at the end of vegetative growth . Obg was a membrane-bound protein as determined by immunoelectron microscopy. Infect Immun, 1998 Nov, 66(11), 5534 - 6 Murine model of Bartonella henselae infection in the immunocompetent host; Regnath T et al.; Bartonella henselae is an emerging pathogen causing cat scratch disease, bacillary angiomatosis, and peliosis hepatis . Progress in understanding the pathogenesis of and the immune response to these infections has been limited by the lack of an animal model . Following intraperitoneal infection of C57BL/6 mice with B . henselae, organs were cleared of cultivatable bacteria within 6 days . In contrast, B . henselae DNA could be detected in liver tissue for at least 3 months . Liver tissue showed granulomatous inflammation reaching its highest degree of intensity during the fourth week of infection and resolving within 12 weeks postinfection . This mouse model is applicable to the study of the pathogenesis of B . henselae and the immune response to this pathogen in the immunocompetent host. Infect Immun, 1998 Nov, 66(11), 5494 - 500 High-level expression of Chlamydia psittaci major outer membrane protein in COS cells and in skeletal muscles of turkeys; Vanrompay D et al.; The omp1 genes encoding the major outer membrane proteins (MOMPs) of avian Chlamydia psittaci serovar A and D strains were cloned and sequenced . The nucleotide sequences of the avian C . psittaci serovar A and D MOMP genes were found to be 98.9 and 87.8% identical, respectively, to that of the avian C . psittaci serovar A strain 6BC, 84.6 and 99.8% identical to that of the avian C . psittaci serovar D strain NJ1, 79.1 and 81.1% identical to that of the C . psittaci guinea pig inclusion conjunctivitis strain, 60.9 and 62.5% identical to that of the Chlamydia trachomatis L2 strain, and 57.5 and 60.4% identical to that of the Chlamydia pneumoniae IOL-207 strain . The serovar A or D MOMPs were cloned in the mammalian expression plasmid pcDNA1 . When pcDNA1/MOMP A or pcDNA1/MOMP D was introduced into COS7 cells, a 40-kDa protein that was identical in size, antigenicity, and electrophoretic mobility to native MOMP was produced . Recombinant MOMP (rMOMP) was located in the cytoplasm of transfected COS7 cells as well as in the plasma membrane and was immunoaccessible . Intramuscular administration of pcDNA1/MOMP in specific-pathogen-free turkeys resulted in local expression of rMOMP in its native conformation, after which anti-MOMP antibodies appeared in the serum. Infect Immun, 1998 Nov, 66(11), 5477 - 84 SCID/NCr mice naturally infected with Helicobacter hepaticus develop progressive hepatitis, proliferative typhlitis, and colitis; Li X et al.; Hepatitis, proliferative typhlitis, and colitis were characterized in young adult and older SCID/NCr mice naturally infected with Helicobacter hepaticus . Liver lesions consisted of Kupffer, Ito, and oval cell hyperplasia along with multifocal to coalescing coagulative hepatocyte necrosis . Numerous Warthin-Starry-positive bacteria were observed in the parenchyma, and there were minimal to mild accumulations of monocytic cells and neutrophils . Proliferative typhlitis was characterized by moderate to marked mucosal epithelial cell hyperplasia with mild monocytic and neutrophilic infiltration . Minimal to mild colitis with mucosal epithelial cell hyperplasia of the colon was most marked in older mice . Comparable gastrointestinal lesions were not observed in uninfected control SCID/NCr mice . H . hepaticus was cultured from fetal viscera of 2 of 11 pups sampled late in gestation from infected SCID/NCr females, suggesting transplacental infection of H . hepaticus . As expected, most of the naturally infected SCID/NCr mice had no serum immunoglobulin G response against H . hepaticus . These findings contrast with those in infected immunocompetent A/JCr mice, which develop a significant immune response to H . hepaticus associated with prominent multifocal mononuclear cell infiltrates in the liver, with only rare bacteria observable at the periphery of inflammatory foci or in the biliary canaliculi . The results demonstrate that chronic inflammatory and proliferative lesions simultaneously affecting the liver, cecum, and colon are associated with natural infection of SCID/NCr mice with H . hepaticus and that lesions are progressive with age . Concurrent infection with H . hepaticus may confound studies that have been attributed to similar lesions due to other experimental manipulations of SCID/NCr mice. Infect Immun, 1998 Nov, 66(11), 5113 - 8 Local immune responses to Chlamydia pneumoniae in the lungs of BALB/c mice during primary infection and reinfection; Penttila JM et al.; Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections . In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae . The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge . A mild lymphoid reaction characterized the pathology in the lungs . In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-gamma) . The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220(+)) . After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells . The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site . In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-gamma) CMI response . These results suggest that repeated infections with C . pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C . trachomatis infection models. J Eukaryot Microbiol, 1998 Sep-Oct, 45(5), 475 - 83 Molecular cloning and characterization of a superoxide dismutase (sod) gene in Pneumocystis carinii; Denis CM et al.; This work reports the isolation and characterization of a gene encoding a superoxide dismutase (SOD, EC.1.15.1.1.) from Pneumocystis carinii derived from rat . Sense and antisense oligonucleotides, deduced from SOD amino acid sequences from a wide variety of organisms, allowed amplification of a 669 bp genomic DNA fragment specific to this P . carinii . RACE-PCR was used to obtain the major part of the complementary DNA; the 5'- and 3'-genomic regions were obtained respectively from a Mbol subgenomic library and from an amplified fragment using oligonucleotides designed from the cDNA sequence . Comparison of genomic and cDNA sequences showed an open reading frame of 660 bp interrupted by seven small introns . The deduced amino acid sequence contained 220 residues . Protein sequence alignment demonstrated the highest homology (50.5% identity; 70.3% similarity) with Saccharomyces cerevisiae manganese-SOD (MnSOD) suggesting that P . carinii SOD belongs to the mitochondrial MnSOD group . A putative targeting peptide found at the 5'-end of the P . carinii SOD sequence also suggested its mitochondrial localization. Extremophiles, 1998 Aug, 2(3), 359 - 66 Dietzia natronolimnaios sp . nov., a new member of the genus Dietzia isolated from an east African soda lake; Duckworth AW et al.; Two novel alkaliphilic aerobic organotrophic bacteria have been isolated from a moderately saline and alkaline East African soda lake . The new isolates grow at pH values between 6 and 10, with a pH optimum for growth of 9.0, and at a salt concentration between 0% and 10% (w/v) . Phylogenetic analysis based on 16S rDNA sequence shows that these isolates are very closely related (99.6% similarity) and are members of the monospecific genus Dietzia (98.8% and 98.7% similarity) . DNA/DNA hybridization revealed a relatedness of 83% between the two isolates, but only 8% between them and the type strain Dietzia maris . The G + C content as measured by thermal denaturation is 66.1 mol% . Phenotypic comparisons between D . maris and one isolate showed that they share very similar morphological and chemotaxonomic properties, but differ significantly in carbon source utilization profiles and halotolerance in alkaline medium . We propose a second species of this genus which we name Dietzia natronolimnaios (type strain 15LN1 = CBS 107.95). Ostomy Wound Manage, 1998 Aug, 44(8), 44 - 52 Wound infection: a nurse's perspective; Fowler E; There is clinical uncertainty about the involvement of bacteria in open wounds . Frequently asked questions are: Is this wound infected? Should I culture the wound? How should I clean the wound? Do I need to use sterile technique when I perform local wound care? Using available science and common sense, a practical approach is proposed to answer these questions. Wien Klin Wochenschr, 1998 Aug 21, 110(15), 511 - 20 Genesis of the uraemic syndrome: role of uraemic toxins; Horl WH; A variety of signs and symptoms constituting the uraemic syndrome may be related to the retention and accumulation of uraemic toxins . Several identified (and yet unidentified) uraemic toxins of low molecular weight are removed at least in part by dialysis therapy resulting in marked improvement of multiple organ dysfunctions and clinical symptoms . However, many abnormalities persist due to the high protein binding of several uraemic toxins or their high molecular weight associated with inadequate dialysis clearance . Moreover, carbamoylation of amino acids and proteins in uraemia as well as metabolic acidosis contribute to the functional and metabolic abnormalities of the uraemic state . Uraemia interferes with the function of polymor-phonuclear leukocytes by deranging their cellular biochemistry and biology . P-cresol and several newly identified granulocyte inhibitory proteins are responsible for reduced chemotaxis, oxidative activity, intracellular killing of bacteria, and glucose consumption by polymorphonuclear leukocytes . Hyperhomocysteinaemia is an independent risk factor for vascular disease in end-stage renal disease patients . Uraemic toxins interfere with calcitriol synthesis and concentration or activity of the calcitriol receptor . Advanced glycolysation end-products (AGEs) accumulate as a result of impaired renal excretion . AGE peptides may represent a modern-day version of "middle molecule" toxicity or uraemia . Of potential clinical importance are pentosidine-, imidazolone- and carboxymethyllysine-modifications of beta 2-microglobulin with respect to the development of uraemia associated amyloidosis . Several uraemic toxins also affect nitric oxide pathway . Particularly, dimethyl-L-arginine (ADMA) is a potent inhibitor of nitric oxide synthesis . Parathyroid hormone satisfies the strict criteria of an uraemic toxin . Many uraemic symptoms can be attributed to the excess of parathyroid hormone in patients with chronic renal failure . Finally, recent investigations indicate, that one or more dialyzable uraemic toxin(s) suppress(es) appetite and may contribute to malnutrition in uraemia. Adv Exp Med Biol, 1998, 440, 355 - 9 Coronavirus nucleocapsid protein . RNA interactions; Cologna R et al.; The coronavirus nucleocapsid protein (N) is involved in encapsidation and packaging of viral RNA . In this study we investigated the ability of the bovine coronavirus (BCV) N protein to interact with RNA . Histidine-tagged BCV N (his-N) protein was expressed in bacteria . A filter binding assay was established to quantitatively measure the binding efficiency of purified his-N to different RNAs . The results indicate that bacterially expressed N bound both BCV and mouse hepatitis coronavirus (MHV) RNAs . Binding to in vitro generated BCV and MHV RNA transcripts was significantly higher than binding to a non-coronavirus RNA . Similar binding efficiencies were measured for a BCV defective genome, pDrep, and a transcript that contained the MHV packaging signal . Interestingly, the entire MHV DI, pMIDI-C, was bound at a higher efficiency than the packaging signal alone . This is one of the first reports to show that N interacts with the MHV packaging signal. Acta Anat (Basel), 1998, 161(1-4), 7 - 17 Glycoproteins now and then: a personal account; Sharon N; The present article opens with a brief summary of the current knowledge of glycoproteins and their medical applications, as compared to the almost complete ignorance of these substances during the first half of the century . The author then relates how he became interested in carbohydrates in the 1950s, and subsequently in glycoproteins . He focuses on the identification of soybean agglutinin as the first known plant protein of this class, to which a widely occurring N-linked oligomannoside is attached, and continues with an account of his work on the coral tree lectin that contains plant-specific N-glycans . Moving at the same time deep into lectin research, he describes the discovery of the crucial role of bacterial surface lectins in the initiation of infectious diseases, thus providing the rationale for the current attempts to use carbohydrates for antiadhesion therapy of such diseases . The article ends with a survey of the author's contribution to spreading wide the knowledge of glycoproteins and of their great importance in biology and medicine. Adv Exp Med Biol, 1998, 439, 249 - 67 Flavonoids as hormones . A perspective from an analysis of molecular fossils; Baker ME; Although for centuries plants have been known to have hormone-like actions in humans, the mechanism(s) by which plant-derived compounds act in humans is still being elucidated, a goal that has assumed more importance due to interest in the protective actions of fruits and vegetables in diseases such as cancer . Here I use the "molecular fossil record" of amino acid sequences of proteins involved in regulating the actions steroids, retinoids, thyroid hormone and prostaglandins to propose some mechanisms by which flavonoids in fruits and vegetables can have hormone-like actions in humans . I focus on: i) hormone receptors that bind to DNA and regulate gene transcription and ii) the enzymes that regulate the concentrations of these hormones . Comparative analyses of amino acid sequences show that nuclear receptors for steroids, retinoids, thyroid hormone and prostaglandins in humans and insects are descended from a common ancestor . Similar analyses of dehydrogenases that regulate the concentrations of steroids, retinoids and prostaglandins reveal strong sequence similarity to enzymes in plants, insects, fungi, and bacteria . The similarity is sufficient to suggest that some compounds that bind receptors or enzymes in invertebrates, plants or unicellular organisms may also bind to mammalian homologs that are involved in endocrine physiology . Among the phytochemicals that are candidates for such activity are flavonoids because they are involved in plant-insect and plant-bacteria interactions and have some structural and chemical similarities to steroids, retinoids, thyroid hormone, prostaglandins and fatty acids . These similarities and the kinship of human, plant, insect and bacterial proteins involved in signal transduction provide a conceptual framework for investigating flavonoids for hormone-like actions in humans . Understanding these modes of action may be useful in developing protocols for preventing hormone-dependent diseases such as breast and prostate cancer. J Hist Dent, 1998 Jul, 46(2), 53 - 7 Leeuwenhoek and Vermeer, an association of genius; Shklar G; Antony van Leeuwenhoek, the inventor of the microscope and originator of the microscopic sciences, had an interesting association with the great Dutch artist, Vermeer, whose paintings were recently displayed in major exhibitions in Holland and the U.S.A . Leeuwenhoek is of particular interest to dental medicine for the first description of the oral bacteria and the first microscopic description of the stratified squamous epithelium of the oral mucosa, with its different layers from stratum germinativum to stratum corneum. Clin Ter, 1998 Mar-Apr, 149(2), 151 - 4 {Sulbactam-ampicillin monotherapy in the ambulatory treatment of pneumonia . Results of mono-administration}; Natale F et al.; Since ampicillin, the parent drug of aminopenicillins, is hydrolyzed by penicillinase, it is normally used in association with sulbactam, a sodium penicillinate sulfone with potent inhibiting activity on type II, III, IV, and V beta-lactamases . The combination ampicillin-sulbactam has been found remarkably useful for the treatment of severe community pneumonia caused by bacteria resistant to ampicillin alone . Approximately 300 patients with community pneumonia of various degrees of severity have been treated with a single dose of 3-4 g ampicillin-sulbactam either diluted in normal saline or in dextrose solution, usually associated with methylprednisolone 20 mg or betametasone 8 mg (tapered) . As assessed by clinical and radiological findings, recovery has been obtained all cases. J Infect Dis, 1998 Nov, 178(5), 1521 - 5 Helicobacter pylori urease significantly reduces opsonization by human complement; Rokita E et al.; The role of Helicobacter pylori urease in opsonization by human complement was investigated . H . pylori wild type strain N6 and isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) were incubated with different sera . C3b bound to the bacteria was measured by specific staining and flow cytometry . As compared with opsonization of N6 and the UreG-lacking mutant, opsonization of the UreB-lacking mutant was significantly increased after incubation with sera from both H . pylori uninfected (P<.001) or infected (P<.05) persons . However, when sera from uninfected persons were used, effective opsonization of this mutant proved to be dependent mainly on the classical pathway of complement activation . Irrespective of the serum used, opsonization values were very low after selective inactivation of the classical or the alternative pathway . Reduced opsonization of the urease-expressing strains could, to some extent, result from degradation of bound C3b. J Infect Dis, 1998 Nov, 178(5), 1399 - 405 Vaccination of gnotobiotic piglets against Helicobacter pylori; Eaton KA et al.; To determine the effect of oral adjuvant-assisted and parenteral vaccination, germ-free piglets were vaccinated orally with and without labile toxin adjuvant or parenterally and challenged with viable Helicobacter pylori . All prechallenge vaccination regimens induced anti-H . pylori antibodies and suppressed bacterial colonization, but no vaccination regime completely prevented infection . Parenteral vaccination given after infection had no effect on bacterial colonization . Lymphocytic gastritis was present in all piglets challenged with live bacteria regardless of vaccination status . Neutrophilic gastritis was present in vaccinated challenged piglets but not in infected, unvaccinated piglets . Gastritis was not present in uninfected control piglets regardless of vaccination status . In gnotobiotic piglets, vaccination suppresses but does not prevent infection by H . pylori, and parenteral vaccination does not cure infected piglets . Vaccination does not ameliorate gastritis due to H . pylori in piglets but does induce neutrophilic gastric inflammation in some infected piglets. Cardiology, 1998 Oct, 90(2), 83 - 8 Lack of evidence for a pathogenic role of Chlamydia pneumoniae and cytomegalovirus infection in coronary atheroma formation; Daus H et al.; Atherosclerotic cardiovascular disease is generally accepted to be the result of metabolic disturbances . However, recent studies have suggested an infectious agent, especially Chlamydia pneumoniae or cytomegalovirus, to be involved in the pathogenesis of atherosclerosis . Atherosclerotic plaque specimens obtained from patients with coronary disease either by balloon dilatation catheter (13 cases) or atherectomy (16 patients) were examined for the presence of C . pneumoniae and cytomegalovirus . Using two primer pairs for C . pneumoniae, two primer pairs for the identification of unknown bacteria and primer pairs for the detection of immediate early gene E2 and the late genomic region of cytomegalovirus, we were unable to detect the suspected agents . The absence of C . pneumoniae, other bacteria and CMV in coronary atheromas is against the hypothesis of a pathogenetic role of these agents in coronary atheroma formation in the patients studied. Acta Radiol Suppl, 1998, 419, 7 - 35 The influence of radiographic contrast media on some granulocyte functions; Rasmussen F; Radiographic CM are used to change the X-ray absorption of tissue . They have been used since the 1930's and today four main types are available . All these CM are derived from one original structure: the 2,4,6 triiodobenzoic acid with the substituents in positions 1,2 and 5 as a carboxylic group or amides . According to the nature of the substituents and the number of aromatic rings, the four different types of CM can be identified . Three of the four types of CM are hyperosmolar, some of the ionic CM contain meglumine and all CM contain calcium disodium EDTA . To fulfil their role in host defence, circulatory PMN must adhere to endothelium of capillaries and venules adjacent to the inflammatory locus, migrate through the vessel wall to the area of inflammation, phagocytose opsonized bacteria, kill ingested organisms and, finally, inactivate their own toxic products to prevent damage to normal tissue . CM should be biologically inert, but many physiological and pathophysiological effects have been described . This review deals with the present knowledge about the influence of CM on PMN . This thesis presents results of the effects of the four main types of CM on PMN exocytosis of elastase and lactoferrin, adherence to nylon fibers, chemotaxis under agarose and phagocytosis of latex particles, as well after in vitro exposure of CM to PMN and after intravascular injection of CM . After in vitro exposure of CM to whole blood, a dose-dependent fall in lactoferrin and elastase concentration was observed, statistically significant for diatrizoate and ioxaglate at high concentrations . I.v . injection of iohexol or ioxaglate resulted in small, although statistical, decreases in lactoferrin concentration in plasma . No differences between the CM groups were seen . PMN adherence to nylon fibers after incubation of CM with whole blood or isolated PMNs was inhibited . The most inhibitive agents were the ionic CM diatrizoate and ioxaglate . The meglumine ion was found to contribute to the inhibitive effect of diatrizoate upon adherence . Following i.v . injection of iohexol or ioxaglate, increased numbers of PMNs, in combination with decreased adherence, were noted with ioxaglate, and the opposite with iohexol . Immediately after arteriography with iohexol and ioxaglate, a small increase of PMN count, in combination with decreased adherence, could be seen . An inhibition of adherence will result in a shift from the marginal to the circulatory pool of PMNs and thus an increase in PMN count . Although statistically significant the changes were minor . A pronounced increase in PMN count was seen 2-5 hours after arteriography in combination with a decrease in adherence . These changes may be due to a release of glucocorticoids from the adrenals in response to the procedure and/or the injection of CM . CMs do not act as chemoattractants . However, when CM are added to the chemoattractant N-fMLP in the under agarose assay, the number of PMNs migrating (density) was lowered, while the distance migrated by the leading front was not affected except for diatrizoate that almost abolished migration . When diatrizoate was added to PMNs, a dose-dependent inhibition was observed . Following i.v . injection of CM, no changes in PMN chemotaxis or changes in the chemoattractive potential of serum could be demonstrated compared to the baseline levels . The ability of PMNs to ingest latex particles after incubation with CM was inhibited in a dose-dependent way . The most inhibitive agents were diatrizoate and ioxaglate . A solution containing the same amount of disodium calcium EDTA as the CM solutions inhibited phagocytosis significantly, although less than the CM solution . Improved phagocytosis was observed in hyperosmolar environments due to NaCl or mannitol at osmolarities higher than 369 mOsm . I.v . injection of ioxaglate or iohexol inhibited the phagocytosis of latex particles by PMNs . The impairment was most pronounced immediately after the injection, and had almost returned to ba Yakugaku Zasshi, 1998 Sep, 118(9), 415 - 22 {Inactivation and toxoiding of biologically-active components of Bordetella pertussis by tea catechins}; Watanabe M et al.; An ability of tea catechins known as agents for the disinfection to bacteria and viruses were tested on application for toxoiding biologically active components of Bordetella pertussis . The effects on the activities and antigenicity of filamentous hemagglutinin (FHA) and pertussis toxin (PT) were investigated . The activities of FHA and PT were inactivated by catechins at approximately 10(3) times lower dose (0.2 mM) compared with that of formalin . The activity of inactivated FHA was recovered by dialysis against Tris-HCl buffer, pH 8.0, containing glutathione or Tris-HCl buffer, pH 6.0 . But the activity of inactivated PT was not recovered . Antigenicity of catechin-treated antigens were investigated by immunization to mice . The sera from mice immunized by catechin-treated FHA or PT were contained antibody against not only catechin-treated but also non-treated FHA or PT . These results suggest that antigenicity of FHA or PT was not destroyed by the treatment with catechin . We prepared pertussis-component vaccines by treatment of several catechins on the condition that FHA or PT activity was not recovered . Higher efficacy were found on the vaccines made by treatment of epicatechin, epicatechin gallate, or epigallocatechin than those by formalin . The vaccine prepared by using epigallocatechin gallate had significant efficacy as well as that by formalin treated one . From these results, it is suggested that tea leaf catechins were effective agents for toxoiding of vaccine components. Curr Biol, 1998 Oct 8, 8(20), 1129 - 32 Caspases and programmed cell death in the hypersensitive response of plants to pathogens; del Pozo O et al.; The hypersensitive response (HR) is induced by certain plant pathogens and involves programmed cell death (PCD) to restrict the spread of pathogens from the infection site {1} . Concurrent with the induction of cell death, the host activates a defense response {2} . The cell death associated with the HR in several plant-pathogen systems has morphological similarities to animal apoptosis {3,4}, which suggests that cell death mechanisms in plants and animals may share common components that lead to similar cellular events . Caspases are conserved cysteine proteases that regulate animal PCD {5}; caspase activity or an involvement of caspases in cell death has yet to be reported in plants . In this work, we investigated the participation of caspases in HR cell death . Caspase-specific peptide inhibitors, Ac-YVAD-CMK {6} and Ac-DEVD-CHO {7}, could abolish bacteria-induced plant PCD but did not significantly affect the induction of other aspects of HR, such as the expression of defense genes . This result confirmed our previous model that cell death can be uncoupled from defense gene activation during HR {8} . Caspase-like proteolytic activity was detected in tobacco tissues that were developing HR following infection with tobacco mosaic virus (TMV) . Our results provide evidence for the presence of caspase-like plant protease(s) that participate in HR cell death. Biochemistry, 1998 Oct 20, 37(42), 14900 - 9 Triplet properties and interactions of the primary electron donor and antenna chromophores in membranes of Heliobacterium chlorum, studied with ADMR spectroscopy; Vrieze J et al.; The triplet states of antenna and reaction center bacteriochlorophyll (BChl) g in membranes of Heliobacterium chlorum were studied by optically detected magnetic resonance in zero magnetic field, using absorbance detection . A variety of triplet states was detected, which were all localized on single BChl g chromophores as concluded from a comparison with the triplet state of monomeric BChl g in organic solvents . With the aid of the microwave-induced absorbance difference spectra, we assign a triplet state with zero-field splitting parameters |D| = 727.5 and |E| = 254 . 5 MHz to that of the primary donor . The low |E| value indicates that the BChls of the primary donor are monoligated . The intensities of the zero-field transitions were strongly dependent on the redox state of the secondary electron acceptors . A triplet state with |D| = 690-705 MHz and |E| =230 MHz, present under all redox conditions, is associated with antenna BChl g absorbing at 814 nm . Its triplet yield was independent of the redox conditions; we conclude therefore that the antenna chromophores absorbing at 814 nm are not connected with the reaction center at cryogenic temperatures (1.2 K) . In addition, relatively strong signals were detected belonging to triplet states with |D| and |E| of 663-680 and 220-227 MHz, respectively, whose amplitudes were dependent on the redox conditions . Triplet states with these zero-field splitting parameters are located on antenna chromophores absorbing between 798-814 nm; their zero-field transitions and absorbance difference spectra indicate a considerable heterogeneity . The concentration of triplet states of antenna chromophores absorbing around 800 nm decreased markedly upon prolonged excitation at 1.2 K . This phenomenon is attributed to quenching of excitations on antenna pigments by stable charge separation in the closely connected reaction center, possibly involving a low-quantum yield menaquinone electron acceptor. Am J Surg, 1998 Aug, 176(2A Suppl), 11S - 19S The development and complications of diabetic foot ulcers; Laing P; Neuropathy and ischemia, two common complications of diabetes mellitus, are the primary underlying risk factors for the development of foot ulcers and their complications . The presence of symmetric distal polyneuropathy, encompassing motor, sensory, and autonomic involvement, is one of the most important factors in the development of diabetic foot ulcers . Perhaps one third of diabetic foot ulcers have a mixed neuropathic and ischemic etiology . Although neuropathy and ischemia are the primary predisposing factors in the formation of diabetic foot ulcers, an initiating factor, such as physical or mechanical stress, is required for an ulcer to develop . Ischemic ulcers develop as a result of low perfusion pressure in a foot with inadequate blood supply, whereas neuropathic ulcers result from higher pressures in a foot with adequate blood supply but loss of protective sensation . In addition to increasing the risk of ulceration, diabetes mellitus also increases the risk of infection by impairing the body's ability to eliminate bacteria . The processes by which ulcers develop are reviewed here. Immunobiology, 1998 Aug, 199(2), 190 - 9 Ficolins and the fibrinogen-like domain; Lu J et al.; Ficolins are a group of proteins containing collagen-like and fibrinogen-like (FBG) sequences and they have a similar overall structure to C1q and the collectins . There are two types of ficolin in man: L-ficolin and M-ficolin . L-ficolin is synthesized in the liver and secreted into the plasma . It binds to several apparently unrelated structures including sugar residues and enhances phagocytosis of bound bacteria . M-ficolin is synthesized mainly in monocytes and is detected on the monocyte surface . The polypeptide sequences of ficolins, the collectins and C1q diverge mainly in their C-terminal globular regions which are, respectively, FBG domains, Ca(2+)-dependent carbohydrate recognition domains (C-type CRD), and collagen-related sequences . The FBG domain consists of 220-250 residues and is found in a number of proteins besides fibrinogen and ficolins . The crystal structure of the FBG domain has been characterized and the elucidation of its binding properties should provide essential insights into its role in ficolins and other proteins. Avian Dis, 1998 Jul-Sep, 42(3), 613 - 7 Isolation of Georgia variant (Georgia isolate 1992) infectious bronchitis virus but not Ornithobacterium rhinotracheale from a Kentucky broiler complex; Erbeck DH et al.; Integrated broiler production operations in western Kentucky have been very successful . The reason for this success includes the fact that flocks are free of many endemic diseases for a period of time, often years, because birds are raised in virgin, disease-free territory . This case report documents that importation of birds from an area with endemic Georgia variant (GA-92) infectious bronchitis virus and Ornithobacterium rhinotracheale (ORT) bacterial infection resulted in introduction of GA-92, but not ORT, to Kentucky farms . As more broiler production units locate in western Kentucky, in the early phases of operation, they may not experience the "virgin territory," disease-free advantage. Avian Dis, 1998 Jul-Sep, 42(3), 572 - 8 Vaccination of chickens against Ornithobacterium rhinotracheale infection; van Empel P et al.; Vaccination of young broilers with inactivated vaccines against experimental Ornithobacterium rhinotracheale challenge was found to be effective, but the results of vaccination were influenced, in a negative way, by the presence of maternal antibodies . The use of a strong adjuvant, such as mineral oil, in a bacterin was necessary to obtain good protection when maternal antibodies were present . Vaccination of broiler breeders resulted in high serologic responses and protection of their progeny against experimental O . rhinotracheale challenge up to an age of 4 wk . Vaccination of broilers with a live vaccine was found to be effective when the maternal antibody levels were low . A combination of vaccinating the breeders with a bacterin and their progeny with a live vaccine at approximately 3 wk of age seems to be the best way to protect broilers against O . rhinotracheale infection. J Biomed Mater Res, 1998 Nov, 42(2), 272 - 7 The effect on immunocytes of anodic oxide titanium after hydrothermal treatment; Takebe J et al.; All dental root implants come in contact with the oral epithelium, and many complex factors are found to arise in this region . In order to perform a successful dental root implantation, it is necessary to clarify the interaction of the dental root implant material with the host defense mechanisms involved in the specific and nonspecific immune responses to many antigens in oral bacteria and their components . Recently, focusing on developing the dental root implant, the Nikon Corporation improved the surface characteristics of pure titanium even further by developing a hydroxyapatite (HA) layer formed on an anodic titanium oxide film containing Ca and P via hydrothermal treatment (SA treatment) . However, since little is known about the effect of SA-treated pure titanium (HA/Ti) on the defense mechanisms of the oral membrane epithelium, we investigated (1) the in vitro proliferation of murine splenic B lymphocytes on the surface of HA/Ti in the presence of three lipopolysaccharide (LPS) concentrations and (2) interleukin-1alpha (IL-1alpha) production by the reaction of human peripheral blood mononuclear cells (PBM cells) on the surface of HA/Ti under the same concentrations . After culture, murine splenic lymphocytes were measured by uptake of 3H-thymidine, and cytokine release (IL-1alpha) from PBM cells was measured by ELISA . Results showed that HA/Ti had hardly any effect on the LPS-induced proliferation of B lymphocytes and IL-1alpha production . In vitro investigations of the effects of HA/Ti on the LPS-induced proliferation of murine splenic B lymphocytes and IL-1alpha from PBM cells might be a useful way of elucidating the defense mechanism between implants and the oral epithelium. J Histochem Cytochem, 1998 Nov, 46(11), 1243 - 8 Immunohistochemical analysis of the distribution of the human ATPase (hASNA-I) in normal tissues and its overexpression in breast adenomas and carcinomas; Kurdi-Haidar B et al.; Human ATPase (hASNA-I) is a novel human gene recently cloned on the basis of homology to the arsA gene of bacteria . Its protein product is an ATPase that is free in the cytoplasm and bound in the perinuclear area and nucleolus in human cells . We prepared the hASNA-I-specific 5G8 monoclonal antibody and used it to investigate the expression of hASNA-I in normal human tissues and breast cancers . hASNA-I was detected immunohistochemically only in the epithelial cells of the liver, kidney, and stomach wall, in the adrenal medulla, in the islet cells of the pancreas, in the red pulp of the spleen, and in cardiac and skeletal muscle . No staining was observed in the uterus, testis, lung, thyroid, cerebellum, and large intestine . Although no staining was also observed in normal breast tissue, all four cases of breast fibroadenomas and all 15 cases of either primary or metastatic breast carcinoma demonstrated increased staining . No embryological or functional common denominator is readily apparent . However, the increased expression in malignant breast cells is of particular interest with respect to the use of this antibody for screening of cytological specimens. J Biol Chem, 1998 Oct 23, 273(43), 27786 - 93 An eukaryotic RuvB-like protein (RUVBL1) essential for growth; Qiu XB et al.; A human protein (RUVBL1), consisting of 456 amino acids (50 kDa) and highly homologous to RuvB, was identified by using the 14-kDa subunit of replication protein A (hsRPA3) as bait in a yeast two-hybrid system . RuvB is a bacterial protein involved in genetic recombination that bears structural similarity to subunits of the RF-C clamp loader family of proteins . Fluorescence in situ hybridization analysis demonstrated that the RUVBL1 gene is located at 3q21, a region with frequent rearrangements in different types of leukemia and solid tumors . RUVBL1 co-immunoprecipitated with at least three other unidentified cellular proteins and was detected in the RNA polymerase II holoenzyme complex purified over multiple chromatographic steps . In addition, two yeast homologs, scRUVBL1 and scRUVBL2 with 70 and 42% identity to RUVBL1, respectively, were revealed by screening the complete Saccharomyces cerevisiae genome sequence . Yeast with a null mutation in scRUVBL1 was nonviable . Thus RUVBL1 is an eukaryotic member of the RuvB/clamp loader family of structurally related proteins from bacteria and eukaryotes that is essential for viability of yeast. Am J Gastroenterol, 1998 Oct, 93(10), 1996 - 8 Helicobacter colonization of the biliary tree: commensal, pathogen, or spurious finding? Metz DC. The authors hypothesized that Helicobacter species may be present in the bile and gallbladder wall of patients with chronic cholecystitis who live in a region with a high prevalence of gallbladder cancer . They attempted to identify such species by obtaining both bile and resected gallbladder tissue from 46 patients who underwent cholecystectomy . Tissue specimens were stained with hematoxylin and eosin as well as other stains used specifically for the identification of Helicobacter species, and culture was attempted using specialized media on samples from tissue and bile . Unfortunately, the authors were unable to culture any Helicobacter species, and the yield from histopathology was also poor with silver stains identifying curved bacteria suggestive, but not diagnostic, of Helicobacter species in only two cases . Molecular techniques were more successful . DNA was extracted from both tissue and bile and amplified by polymerase chain reaction (PCR) using a specific primer . The amplicons they identified were then compared with known Helicobacter proteins using a Southern blot approach . PCR amplification was relatively successful with 9 of 23 gallbladder samples and 13 of the 23 bile samples coming up positive for Helicobacter species using two specific primers . These specimens were also positive by Southern blot hybridization . The cloning and sequencing of the 16S ribosomal RNA amplicons in eight cases verified true Helicobacter origin with a phylogenetic analysis showing greater than 99.3% similarity . Five of the amplicons clustered with H . bilis, two with Flexispira rappini, and one with H . pullorum . The authors concluded that despite their being unable to identify organisms directly, the stringent PCR technique with amplicon sequencing confirmed that Helicobacter species could be identified within the bile and gallbladder tissue of patients with chronic cholecystitis in a region with high incidence of gallbladder cancer . They indicated that further studies are needed to ascertain whether similar species have a causative role in the development of gallbladder cancer. Life Sci, 1998, 63(14), 1251 - 67 Some chemical properties and biological role of thiazolidine compounds; Terzuoli L et al.; In this study we have investigated some chemical properties and the biological role of thiazolidine compounds, obtained by condensation of aminothiols (L- or D-cysteine, cysteamine) with pyridoxal-5'-phosphate . These products have been tested in presence of rat liver extracts (supernatant and mitochondria); bacterial suspensions and enzymes (L- or D-aminoacid oxidase, xanthine oxidase) with interesting results which gives evidence to a biological role . Their formation in vivo may represent the regulation of intracellular levels of pyridoxal-5'-phosphate and aminothiols . Moreover, we have analysed the two diastereoisomers of the thiazolidine compounds derived from L-cysteine and D-cysteine: we have succeeded to distinguish by NMR analysis the cis and the trans forms, concluding that the interconversion of the free forms is extremely rapid at pH 7: thus, it may be relevant for the protein bound forms. Probl Tuberk, 1998, (4), 13 - 4 {Dynamics of morbidity at health care institutions and penal labor facilities in the Udmurt Republic}; Russkikh OE et al.; Comparative analysis indicated that morbidity in the corrective labour institutions, Ministry Internal Affairs of the Udmurt Republic, is much higher than that in the therapeutical-and-prophylactic institutions of the republic . In the corrective labour institutions, patients who isolate bacteria and who have destructive processes are much more common . The clinical course of clinical tuberculosis is noted to be aggravated, there is an increase in the incidence of caseous pneumonia. Exp Cell Res, 1998 Oct 10, 244(1), 340 - 8 Cytoskeletal association of an esterase in Dictyostelium discoideum; Chia CP et al.; A 70-kDa glycoprotein, gp70, was found enriched in the detergent-insoluble cytoskeletal fraction of axenically grown Dictyostelium discoideum cells . Its N-terminal amino acid sequence identified it as 'crystal protein' (L . Bomblies et al., 1990, J . Cell Biol . 110, 669-679) . This finding was corroborated when antibody to crystal protein cross-reacted with gp70 and its deglycosylated form . The postulated esterase activity of gp70/crystal protein was verified through comparative enzyme assays of extracts derived from cells that either overexpressed or lacked gp70 . Gp70 cosedimented with cytoskeletons on sucrose gradients, suggesting an interaction with the cytoskeleton . Coisolation of gp70 with detergent-extracted cells, observed by immunofluorescence microscopy, also implied a gp70-cytoskeletal association . These data supported the idea that the localization or secretion of gp70, or both, was cytoskeletally mediated . Although axenically grown cells contained high levels of gp70, the same cell lines had reduced levels of gp70 when grown in bacterial suspension or in nutrient media containing bacteria . Bacterially grown cells, compared to axenically grown cells, had lower fluid-phase uptake rates even when nutrient media was present, indicating that phagocytosis was a preferred mode of feeding . Thus, bacteria inhibited gp70 expression, which suggested a role for prestarvation factor, in regulating its synthesis . Pathology, 1998 Aug, 30(3), 295 - 8 Chlamydia pneumoniae DNA is not detectable within sarcoidosis tissue; Mills GD et al.; Sarcoidosis is a granulomatous disease of unknown etiology . Recent studies have suggested the possibility of a bacterial origin with Chlamydia pneumoniae being one of the many bacteria considered . The aim of this study was to use the polymerase chain reaction (PCR) in an attempt to identify C . pneumoniae within fresh/frozen sarcoidosis tissue . Tissue from 20 sarcoidosis patients and 17 controls was evaluated . DNA was extracted from all tissue specimens and PCR amplified with primers specific for C . pneumoniae . All study tissues were negative for the presence of DNA sequences from C . pneumoniae . These findings could not be attributed to PCR inhibition or to lack of sensitivity of the PCR assay . The negative finding suggests either that there is no involvement between C . pneumoniae and sarcoidosis or that, having incited granulomata formation, it is no longer present in detectable amounts. Pathol Biol (Paris), 1998 Feb, 46(2), 92 - 5 {Compact genomes}; Forterre P; The number of procaryotic genomes (both Archaea and Bacteria) completely sequenced is rapidly increasing since the publication in 1995 of the first ever finished one, Haemophilis influenzae . The small size and "simplicity" of these genomes make them ideal models for training in genomic before attacking more complex genomes, but they have also great intrinsic interest . Preliminary analyses of these compact genomes have detected many orphan genes, even in organisms previously extensively studied, as well as many families of duplicated genes . A major task now is to identify the function of these orphans by a combination of in silico, biochemical and genetic analyses (examples will be presented) . Several genomes of hyperthermophiles have been or will be completely sequenced soon . Many of their genes have commercial (stable proteins), as well as medical interest (crystallization of proteins with eucaryotic homologs involved in pathogenesis) . However, further work with these genomes will require the development of genetic tools for these hyperthermophiles . The complete understanding of genome evolution, structure and function will require the sequencing of many genomes at the different levels of the evolutionary scale . Sequencing of genomes from closely related organisms can be relevant to study genome plasticity, whilst sequencing of genome from different domains (Archaea, Bacteria, Eucarya) can help to reconstruct the Last Universal Common Ancestor (LUCA) . The latter is a difficult task and will require not only classical molecular phylogenetic studies (which can be sometimes greatly misleading) but also in depth comparative analyses of all central genetic mechanisms in the three domains to infer their respective evolution . The fundamental problem is to determine if the compact genome of procaryotes is indeed a primitive one (as suggested by the term procaryote itself) or if it has been compacted from a more complex one by evolutionary forces related to the procaryotic way of life . Finally, taking into account the extreme diversity of procaryotes and their metabolism, it should be kept in mind that beside a core of genes essential for cellular life, the myriad of procaryotic genomes contain a mine of non essential genes with potential commercial or medical application . The total number of these genes probably outnumber the total number of eucaryotic genes. Med Clin North Am, 1998 Sep, 82(5), 1001 - 31, v Infectious diseases; Ko WT et al.; Approximately 5% of the general population develops a skin infection each year, leading to a significant number of outpatient visits to the primary care physician . Bacteria, infestations, fungi, yeasts, and viruses are organisms that present with a myriad of cutaneous findings that pose a challenge to the investigating clinician . This article provides a contemporary review of these skin infections, with particular emphasis on clinical features, and a concise, updated review on therapies. Trends Genet, 1998 Sep, 14(9), 368 - 74 Selfishness and death: raison d'être of restriction, recombination and mitochondria; Kobayashi I; Type II restriction-modification gene complexes, such as the EcoRI system, are not easily lost from their host cell . The descendants of cells that lose a restriction-modification gene complex are unable to modify a sufficient number of recognition sites in their chromosomes to protect them from lethal attack by the remaining molecules of restriction enzyme . This capacity to act as a selfish genetic element is likely to have contributed to the spread and maintenance of restriction-modification systems . Homologous recombination machineries of cells and viruses appear to be well adapted to cope with these elements . By extrapolation, the capacity of mitochondria to kill their host eukaryotic cell might have stabilized their initial symbiosis. Toxicology, 1998 Aug 7, 129(1), 63 - 71 Biomarkers of immunotoxicity in fish and other non-mammalian sentinel species: predictive value for mammals? Zelikoff JT. Through the efforts of different laboratories, a battery of immunological assays is available to predict the immunotoxicity of xenobiotics . These assays, originally developed in rodents, have been adapted for use in a variety of animal species and are now used routinely in these models to assess the immunotoxicity of different chemical classes . For example, our laboratory has employed assays that measure antibody-forming cell response to T-dependent antigens, T- and B-cell lymphoproliferation, macrophage function, and host resistance against infectious bacteria to assess metal-induced immunotoxicity in laboratory-reared Japanese medaka (Oryzias latipes); immunologically-related assays measuring antioxidant activity have also been used in this capacity . Results of the aforementioned investigations have shown the usefulness of these endpoints to reliably demonstrate chemical-mediated immunotoxicity in teleost systems . Many of these same endpoints have also proved successful for predicting the immunotoxic effects of contaminated aquatic environments in feral fish populations . For example, smallmouth bass collected from a chlorinated hydrocarbon-contaminated site demonstrated significant changes in blood cell profiles and kidney phagocyte function compared to fish collected from a 'clean water' reference site . Some of these same immune parameters have also been used successfully to predict the immunotoxicity of polluted aquatic environments in feral populations of fish-eating birds and harbor seals . While interspecies extrapolation is difficult and should be approached with caution due to variables such as metabolism and pharmacokinetics, results from these studies demonstrate the usefulness of these immune assays to predict the immunomodulating effects of xenobiotics in fish and other wildlife species, as well as the applicability of fish to serve as additional/alternate animal models for mammalian species in immunotoxicological studies. Presse Med, 1998 Jun 20, 27(22), 1084 - 8 {Severe pneumonia with a pneumococcal aspect during an ornithosis outbreak}; Goupil F et al.; OBJECTIVES: To describe the clinical, radiological and biological features of Chlamydia psittaci pneumonia . METHODS: A pneumonia outbreak occurred in a healthy middle-aged population working in a poultry slaughterhouse . Systematic serology (2 samples at 5 weeks intervals) provided the diagnosis of Chlamydia psittaci pneumonia in 6 patients . Patient files were analyzed retrospectively . RESULTS: The clinical presentations in this series of pneumonia were particularly homogeneous with a pneumococcal profile in all 6 cases: sudden onset, temperature above 39 degrees C, lobar alveolar involvement, hypoxemia, hyperleukocytosis and liver dysfunction . One case of hallucinatory delirium was observed . The patients were given spiramycin (9 million units per day for 3 weeks) and all recovered rapidly with no complications . CONCLUSION: The unusual virulence of the Chlamydia psittaci and very important inoculum were probably involved in this outbreak because of the severity of the pulmonary features and the short exposure of some patients to the bacteria . These cases suggest that the prevention of ornithosis in poultry slaughterhouses should be reinforced. Mol Microbiol, 1998 Sep, 29(5), 1249 - 61 The pilH gene encodes an ABC transporter homologue required for type IV pilus biogenesis and social gliding motility in Myxococcus xanthus; Wu SS et al.; Type IV pilus genes have been shown to be required for social gliding motility in Myxococcus xanthus . We report the discovery of four additional pil genes: pilD, a homologue of type IV prepilin leader peptidases; and pilG, pilH and pilI, which have no known homologues in other type IV pilus systems . pilH encodes an ATP-binding cassette (ABC) transporter homologue, the first such homologue to be required for the biogenesis of any bacterial pilus type . pilG and pilI are co-transcribed with pilH and appear to be functionally related to pilH . Null mutants of pilG, pilH and pilI all lack social motility, are deficient in pilus production, have elevated sporulation efficiencies and display similar developmental abnormalities . In addition, all three mutations reduced the amount of PilA found