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| Transplantation, 2001 Sep 15, 72(5), 818 - 22 Neuropathy in miniature swine after administration of the mutant diphtheria toxin-based immunotoxin, pCD3-CRM9; Gargollo P et al.; BACKGROUND: Effective in vivo T-cell depletion is a critical component of many transplantation tolerance protocols . We have previously demonstrated T-cell depletion in miniature swine using a CRM9-based CD3-immunotoxin, pCD3-CRM9 . CRM9 is a mutant form of diphtheria toxin (DT) that binds less efficiently than wild-type DT to the DT receptor (proHB-EGF) of primates . In this report, we describe and characterize the dose-dependent neurotoxicity associated with CRM9-based immunotoxin administration in swine . METHODS: Miniature swine were treated with varying doses of pCD3-CRM9 followed by daily monitoring for symptoms of neuropathy, including limb weakness, paresis, sluggishness, and/or respiratory distress . Animals demonstrating severe respiratory distress were euthanized and peripheral nerve, spinal cord, and skeletal muscle tissue samples were obtained at autopsy for microscopic examination . Unconjugated CRM9 was administered to one animal to define its toxicity independent of the effects of T-cell depletion . RESULTS: Excellent T-cell depletion was obtained using doses of pCD3-CRM9 greater than 0.1 mg/kg . However, neurotoxicity was observed at these doses, as manifested by transient muscle weakness or paresis, which in some cases progressed to respiratory failure and death . Dorsal root ganglia samples revealed pathological changes typical of diphtheritic polyneuropathy . The animal receiving unconjugated CRM9 exhibited the same neurotoxic side effects as those receiving the pCD3-CRM9 conjugate . CONCLUSIONS: Administration of pCD3-CRM9 immunotoxin provides excellent T-cell depletion in miniature swine but is associated with significant dose-dependent neurotoxicity . A possible reason for CRM9-associated neurotoxicity in swine, but not primates, is suggested on the basis of a known amino acid difference in the exodomain of the DT receptor (proHB-EGF) of swine compared with that of primates. Appl Environ Microbiol, 2001 Oct, 67(10), 4850 - 7 Detection and enumeration of methanotrophs in acidic Sphagnum peat by 16S rRNA fluorescence in situ hybridization, including the use of newly developed oligonucleotide probes for Methylocella palustris; Dedysh SN et al.; Two 16S rRNA-targeted oligonucleotide probes, Mcell-1026 and Mcell-181, were developed for specific detection of the acidophilic methanotroph Methylocella palustris using fluorescence in situ hybridization (FISH) . The fluorescence signal of probe Mcell-181 was enhanced by its combined application with the oligonucleotide helper probe H158 . Mcell-1026 and Mcell-181, as well as 16S rRNA oligonucleotide probes with reported group specificity for either type I methanotrophs (probes M-84 and M-705) or the Methylosinus/Methylocystis group of type II methanotrophs (probes MA-221 and M-450), were used in FISH to determine the abundance of distinct methanotroph groups in a Sphagnum peat sample of pH 4.2 . M . palustris was enumerated at greater than 10(6) cells per g of peat (wet weight), while the detectable population size of type I methanotrophs was three orders of magnitude below the population level of M . palustris . The cell counts with probe MA-221 suggested that only 10(4) type II methanotrophs per g of peat (wet weight) were present, while the use of probe M-450 revealed more than 10(6) type II methanotroph cells per g of the same samples . This discrepancy was due to the fact that probe M-450 targets almost all currently known strains of Methylosinus and Methylocystis, whereas probe MA-221, originally described as group specific, does not detect a large proportion of Methylocystis strains . The total number of methanotrophic bacteria detected by FISH was 3.0 (+/-0.2) x 10(6) cells per g (wet weight) of peat . This was about 0.8% of the total bacterial cell number . Thus, our study clearly suggests that M . palustris and a defined population of Methylocystis spp . were the predominant methanotrophs detectable by FISH in an acidic Sphagnum peat bog. Appl Environ Microbiol, 2001 Oct, 67(10), 4773 - 80 The glycogen-bound polyphosphate kinase from Sulfolobus acidocaldarius is actually a glycogen synthase; Cardona S et al.; Inorganic polyphosphate (polyP) is obtained by the polymerization of the terminal phosphate of ATP through the action of the enzyme polyphosphate kinase (PPK) . Despite the presence of polyP in every living cell, a gene homologous to that of known PPKs is missing from the currently sequenced genomes of Eukarya, Archaea, and several bacteria . To further study the metabolism of polyP in Archaea, we followed the previously published purification procedure for a glycogen-bound protein of 57 kDa with PPK as well as glycosyl transferase (GT) activities from Sulfolobus acidocaldarius (R . Skorko, J . Osipiuk, and K . O . Stetter, J . Bacteriol . 171:5162-5164, 1989) . In spite of using recently developed specific enzymatic methods to analyze polyP, we could not reproduce the reported PPK activity for the 57-kDa protein and the polyP presumed to be the product of the reaction most likely corresponded to glycogen-bound ATP under our experimental conditions . Furthermore, no PPK activity was found associated to any of the proteins bound to the glycogen-protein complex . We cloned the gene corresponding to the 57-kDa protein by using reverse genetics and functionally characterized it . The predicted product of the gene did not show similarity to any described PPK but to archaeal and bacterial glycogen synthases instead . In agreement with these results, the recombinant protein showed only GT activity . Interestingly, the GT from S . acidocaldarius was phosphorylated in vivo . In conclusion, our results convincingly demonstrate that the glycogen-protein complex of S . acidocaldarius does not contain a PPK activity and that what was previously reported as being glycogen-bound PPK is a bacterial enzyme-like thermostable glycogen synthase. Appl Environ Microbiol, 2001 Oct, 67(10), 4765 - 72 Copper-induced inhibition of growth of Desulfovibrio desulfuricans G20: assessment of its toxicity and correlation with those of zinc and lead; Sani RK et al.; The toxicity of copper {Cu(II)} to sulfate-reducing bacteria (SRB) was studied by using Desulfovibrio desulfuricans G20 in a medium (MTM) developed specifically to test metal toxicity to SRB (R . K . Sani, G . Geesey, and B . M . Peyton, Adv . Environ . Res . 5:269-276, 2001) . The effects of Cu(II) toxicity were observed in terms of inhibition in total cell protein, longer lag times, lower specific growth rates, and in some cases no measurable growth . At only 6 microM, Cu(II) reduced the maximum specific growth rate by 25% and the final cell protein concentration by 18% compared to the copper-free control . Inhibition by Cu(II) of cell yield and maximum specific growth rate increased with increasing concentrations . The Cu(II) concentration causing 50% inhibition in final cell protein was evaluated to be 16 microM . A Cu(II) concentration of 13.3 microM showed 50% inhibition in maximum specific growth rate . These results clearly show significant Cu(II) toxicity to SRB at concentrations that are 100 times lower than previously reported . No measurable growth was observed at 30 microM Cu(II) even after a prolonged incubation of 384 h . In contrast, Zn(II) and Pb(II), at 16 and 5 microM, increased lag times by 48 and 72 h, respectively, but yielded final cell protein concentrations equivalent to those of the zinc- and lead-free controls . Live/dead staining, based on membrane integrity, indicated that while Cu(II), Zn(II), and Pb(II) inhibited growth, these metals did not cause a loss of D . desulfuricans membrane integrity . The results show that D . desulfuricans in the presence of Cu(II) follows a growth pattern clearly different from the pattern followed in the presence of Zn(II) or Pb(II) . It is therefore likely that Cu(II) toxicity proceeds by a mechanism different from that of Zn(II) or Pb(II) toxicity. Appl Environ Microbiol, 2001 Oct, 67(10), 4694 - 700 Response of the endophytic diazotroph Gluconacetobacter diazotrophicus on solid media to changes in atmospheric partial O(2) pressure; Pan B et al.; Gluconacetobacter diazotrophicus is an N(2)-fixing endophyte isolated from sugarcane . G . diazotrophicus was grown on solid medium at atmospheric partial O(2) pressures (pO(2)) of 10, 20, and 30 kPa for 5 to 6 days . Using a flowthrough gas exchange system, nitrogenase activity and respiration rate were then measured at a range of atmospheric pO(2) (5 to 60 kPa) . Nitrogenase activity was measured by H(2) evolution in N(2)-O(2) and in Ar-O(2), and respiration rate was measured by CO(2) evolution in N(2)-O(2) . To validate the use of H(2) production as an assay for nitrogenase activity, a non-N(2)-fixing (Nif(-)) mutant of G . diazotrophicus was tested and found to have a low rate of uptake hydrogenase (Hup(+)) activity (0.016 +/- 0.009 micromol of H(2) 10(10) cells(-1) h(-1)) when incubated in an atmosphere enriched in H(2) . However, Hup(+) activity was not detectable under the normal assay conditions used in our experiments . G . diazotrophicus fixed nitrogen at all atmospheric pO(2) tested . However, when the assay atmospheric pO(2) was below the level at which the colonies had been grown, nitrogenase activity was decreased . Optimal atmospheric pO(2) for nitrogenase activity was 0 to 20 kPa above the pO(2) at which the bacteria had been grown . As atmospheric pO(2) was increased in 10-kPa steps to the highest levels (40 to 60 kPa), nitrogenase activity decreased in a stepwise manner . Despite the decrease in nitrogenase activity as atmospheric pO(2) was increased, respiration rate increased marginally . A large single-step increase in atmospheric pO(2) from 20 to 60 kPa caused a rapid 84% decrease in nitrogenase activity . However, upon returning to 20 kPa of O(2), 80% of nitrogenase activity was recovered within 10 min, indicating a "switch-off/switch-on" O(2) protection mechanism of nitrogenase activity . Our study demonstrates that colonies of G . diazotrophicus can fix N(2) at a wide range of atmospheric pO(2) and can adapt to maintain nitrogenase activity in response to both long-term and short-term changes in atmospheric pO(2). BMC Microbiol . 2001;1(1):19 . Epub 2001 Aug 31. amiA is a negative regulator of acetamidase expression in Mycobacterium smegmatis; Parish T et al.; BACKGROUND: The acetamidase of Mycobacterium smegmatis is a highly inducible enzyme . Expression of this enzyme is increased 100-fold when the substrate acetamide is present . The acetamidase gene is found immediately downstream of three open reading frames . Two of these are proposed to be involved in regulation . RESULTS: We constructed a deletion mutant in one of the upstream ORFs (amiA) . This mutant (Mad1) showed a constitutively high level of acetamidase expression . We identified four promoters in the upstream region using a beta-galactosidase reporter gene . One of these (P2) was inducible in the wild-type, but was constitutively active in Mad1 . CONCLUSIONS: These results demonstrate that amiA encodes a negative regulatory protein which interacts with P2 . Since amiA has homology to DNA-binding proteins, it is likely that it exerts the regulatory effect by binding to the promoter to prevent transcription. Protein Expr Purif, 2001 Oct, 23(1), 22 - 32 Formation of soluble inclusion bodies by hpv e6 oncoprotein fused to maltose-binding protein; Nomine Y et al.; Many polypeptides overexpressed in bacteria are produced misfolded and accumulate as solid structures called inclusion bodies . Inclusion-body-prone proteins have often been reported to escape precipitation when fused to maltose-binding protein (MBP) . Here, we have examined the case of HPV 16 oncoprotein E6 . The unfused sequence of E6 is overexpressed as inclusion bodies in bacteria . By contrast, fusions of E6 to the C-terminus of MBP are produced soluble . We have analyzed preparations of soluble MBP-E6 fusions by using three independent approaches: dynamic light scattering, lateral turbidimetry, and sandwich ELISA . All three methods showed that MBP-E6 preparations contain highly aggregated material . The behavior of these soluble aggregates under denaturating conditions suggests that they are formed by agglomeration of misfolded E6 moieties . However, precipitation is prevented by the presence of the folded and highly soluble MBP moieties, which maintain the aggregates in solution . Therefore, the fact that a protein or protein domain is produced soluble when fused to the C-terminus of a carrier protein does not guarantee that the protein of interest is properly folded and active . We suggest that aggregation of fusion proteins should be systematically assayed, especially when these fusions are to be used for binding measurements or activity tests . Biotechniques, 2001 Sep, 31(3), 541 - 5 Development of a new epitope tag recognized by a monoclonal antibody to Rickettsia typhi; Lee JR et al.; The epitope recognized by a mouse monoclonal antibody (MAb) to the crystalline surface layer protein of Rickettsia typhi, SRT10, was mapped to 10 amino acid residues (SRTag TFIGAIATDT) . The oligonucleotide sequence covering the epitope recognized by SRT10 was inserted into a mammalian expression vector together with multiple cloning sites . When the SRTag was fused in frame to the coding region of the NCC27/CLIC1 gene and expressed in mammalian cells, the MAb SRT10 could detect the tagged protein by immunoblotting, immunocytochemistry, and immunoprecipitation . In addition to the SRT-NCC27/CLIC1, SRT10 could detect N-terminal-tagged MEF2D and C-terminal-tagged CD4 by immunocytochemistry . We suggest that this specific recognition of the SRTag by SRT10 is generally applicable to cellular and molecular biology research that requires the expression and detection of fusion proteins. C R Acad Sci III, 2001 Oct, 324(10), 929 - 33 {Discovery of the first virus, the tobacco mosaic virus: 1892 or 1898?}; Lecoq H; Two scientists contributed to the discovery of the first virus, Tobacco mosaic virus . Ivanoski reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filter-candle . Bacteria are retained by such filters, a new world was discovered: filterable pathogens . However, Ivanovski probably did not grasp the full meaning of his discovery . Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic . He showed that the incitant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria . Ivanovski and Beijerinck brought unequal but decisive and complementary contributions to the discovery of viruses . Since then, discoveries made on Tobacco mosaic virus have stood out as milestones of virology history. Biofactors, 2001, 14(1-4), 87 - 92 Evolution of selenocysteine-containing proteins: significance of identification and functional characterization of selenoproteins; Gladyshev VN et al.; In the genetic code, UGA serves as either a signal for termination or a codon for selenocysteine (Sec) . Sec rarely occurs in protein and is different from other amino acids in that much of the biosynthetic machinery governing its incorporation into protein is unique to this amino acid . Sec-containing proteins have diverse functions and lack a common amino acid motif or consensus sequence . Sec has previously been considered to be a relic of the primordial genetic code that was counter-selected by the presence of oxygen in the atmosphere . In the present report, it is proposed that Sec was added to the already existing genetic code and its use has accumulated during evolution of eukaryotes culminating in vertebrates . The more recently evolved selenoproteins appear to take advantage of unique redox properties of Sec that are superior to those of Cys for specific biological functions . Further understanding of the evolution of selenoproteins as well as biological properties and biomedical applications of the trace element selenium requires identification and functional characterization of all mammalian selenoproteins. Biofactors, 2001, 14(1-4), 75 - 83 Selenoprotein synthesis in archaea; Rother M et al.; The availability of the genome sequences from several archaea has facilitated the identification of the encoded selenoproteins and also of most of the components of the machinery for selenocysteine biosynthesis and insertion . Until now, selenoproteins have been identified solely in species of the genera Methanococcus (M.) and Methanopyrus . Apart from selenophosphate synthetase, they include only enzymes with a function in energy metabolism . Like in bacteria and eukarya, selenocysteine insertion is directed by a UGA codon in the mRNA and involves the action of a specific tRNA and of selenophosphate as the selenium donor . Major differences to the bacterial system, however, are that no homolog for the bacterial selenocysteine synthase was found and, especially, that the SECIS element of the mRNA is positioned in the 3' nontranslated region . The characterisation of a homolog for the bacterial SelB protein showed that it does not bind to the SECIS element necessitating the activity of at least a second protein . The use of the genetic system of M . maripaludis allowed the heterologous expression of a selenoprotein gene from M . jannaschii and will facilitate the elucidation of the mechanism of the selenocysteine insertion process in the future. J Bacteriol, 2001 Oct, 183(20), 6135 - 9 Glycerol 3-phosphate inhibits swarming and aggregation of Myxococcus xanthus; Moraleda-Munoz A et al.; We have cloned a gene of Myxococcus xanthus with similarities to the permease for glycerol 3-phosphate (G3P) of other bacteria . Expression of the gene increased significantly during the first hours of starvation . Swarming of the wild-type strain was inhibited and aggregation was delayed by G3P . Conversely, a DeltaglpT strain aggregated even on rich medium . These results indicate that G3P may function to regulate the timing of aggregation in M . xanthus. J Bacteriol, 2001 Oct, 183(20), 6119 - 25 The alternative sigma factor SigH regulates major components of oxidative and heat stress responses in Mycobacterium tuberculosis; Raman S et al.; Mycobacterium tuberculosis is a specialized intracellular pathogen that must regulate gene expression to overcome stresses produced by host defenses during infection . SigH is an alternative sigma factor that we have previously shown plays a role in the response to stress of the saprophyte Mycobacterium smegmatis . In this work we investigated the role of sigH in the M . tuberculosis response to heat and oxidative stress . We determined that a M . tuberculosis sigH mutant is more susceptible to oxidative stresses and that the inducible expression of the thioredoxin reductase/thioredoxin genes trxB2/trxC and a gene of unknown function, Rv2466c, is regulated by sigH via expression from promoters directly recognized by SigH . We also determined that the sigH mutant is more susceptible to heat stress and that inducible expression of the heat shock genes dnaK and clpB is positively regulated by sigH . The induction of these heat shock gene promoters but not of other SigH-dependent promoters was markedly greater in response to heat versus oxidative stress, consistent with their additional regulation by a heat-labile repressor . To further understand the role of sigH in the M . tuberculosis stress response, we investigated the regulation of the stress-responsive sigma factor genes sigE and sigB . We determined that inducible expression of sigE is regulated by sigH and that basal and inducible expression of sigB is dependent on sigE and sigH . These data indicate that sigH plays a central role in a network that regulates heat and oxidative-stress responses that are likely to be important in M . tuberculosis pathogenesis. J Bacteriol, 2001 Oct, 183(20), 5997 - 6008 Recombination in the ompA gene but not the omcB gene of Chlamydia contributes to serovar-specific differences in tissue tropism, immune surveillance, and persistence of the organism; Millman KL et al.; Sequences of the major outer membrane protein (MOMP) gene (ompA) and the outer membrane complex B protein gene (omcB) from Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci were analyzed for evidence of intragenic recombination and for linkage equilibrium . The Sawyer runs test, compatibility matrices, and index of association analyses provided substantial evidence that there has been a history of intragenic recombination at ompA including one instance of interspecies recombination between the C . trachomatis mouse pneumonitis strain and the C . pneumoniae horse N16 strain . Although none of these methods detected intragenic recombination within omcB, differences in divergence reported in earlier studies suggested that there has been intergenic recombination involving omcB, and the analyses presented in this study are consistent with this . For C . trachomatis, index-of-association analyses suggested a higher degree of recombination for C class than for B class strains and a higher degree of recombination in the downstream half of ompA . In concordance with these findings, many significant breakpoints were found in variable segments 3 and 4 of MOMP for the recombinant strains D/B120, G/UW-57, E/Bour, and LGV-98 identified in this study . We provide examples of how genetic diversity generated by repeated recombination in these regions may be associated with evasion of immune surveillance, serovar-specific differences in tissue tropism, and persistence. Biophys J, 2001 Oct, 81(4), 2395 - 402 Reliable and global measurement of fluorescence resonance energy transfer using fluorescence microscopes; Xia Z et al.; Green fluorescence protein (GFP)-based fluorescence resonance energy transfer (FRET) is increasingly used in investigation of inter- and intramolecular interactions in living cells . In this report, we present a modified method for FRET quantification in cultured cells using conventional fluorescence microscopy . To reliably measure FRET, three positive control constructs in which a cyan fluorescence protein and a yellow fluorescence protein were linked by peptides of 15, 24, or 37 amino acid residues were prepared . FRET was detected using a spectrofluorometer, a laser scanning confocal microscope, and an inverted fluorescence microscope . Three calculation methods for FRET quantification using fluorescence microscopes were compared . By normalization against expression levels of GFP fusion proteins, the modified method gave consistent FRET values that could be compared among different cells with varying protein expression levels . Whole-cell global analysis using this method allowed FRET measurement with high spatial resolutions . Using such a procedure, the interaction of synaptic proteins syntaxin and the synaptosomal associated protein of 25 kDa (SNAP-25) was examined in PC12 cells, which showed strong FRET on plasma membranes . These results demonstrate the effectiveness of the modified method for FRET measurement in live cell systems. Biophys J, 2001 Oct, 81(4), 2314 - 9 Early photocycle kinetic behavior of the E46A and Y42F mutants of photoactive yellow protein: femtosecond spectroscopy; Devanathan S et al.; In the photoactive yellow protein, PYP, both Glu46 and Tyr42 form hydrogen bonds to the phenolic OH group of the p-hydroxycinnamoyl chromophore . Previous work on replacement of the carboxyl group of Glu46 by an amide group (Glu46Gln) has shown that changing the nature of this hydrogen bond has a minimal effect on the rate constant for the formation of the first intermediate (I(0)) and on the excited state lifetime, whereas the rate constants for the formation of the second (I(0)( not equal)) and third (I(1)) intermediates were increased by factors of approximately 30 and 5, respectively . In the present experiments, two additional mutants (Glu46Ala and Tyr42Phe) have been studied . These two mutants are shown to behave kinetically very similarly to one another . In both cases, the rate constant for I(0) formation is decreased by a factor of approximately 2, with little or no effect on the photochemical yield as a consequence of a compensating increase in the excited state lifetime . Although we are unable to resolve the rate constant for the formation of the second intermediate from that of the first intermediate, the rate constant for the formation of the third intermediate is increased by a factor of approximately 100 . The structural implications of these results are discussed. Biophys J, 2001 Oct, 81(4), 2082 - 99 Two-dimensional kinetic analysis suggests nonsequential gating of mechanosensitive channels in Xenopus oocytes; Gil Z et al.; Xenopus oocytes express mechanosensitive (MS(XO)) channels that can be studied in excised patches of membrane with the patch-clamp technique . This study examines the steady-state kinetic gating properties of MS(XO) channels using detailed single-channel analysis . The open and closed one-dimensional dwell-time distributions were described by the sums of 2-3 open and 5-7 closed exponential components, respectively, indicating that the channels enter at least 2-3 open and 5-7 closed kinetic states during gating . Dependency plots revealed that the durations of adjacent open and closed intervals were correlated, indicating two or more gateway states in the gating mechanism for MS channels . Maximum likelihood fitting of two-dimensional dwell-time distributions to both generic and specific models was used to examine gating mechanism and rank models . A kinetic scheme with five closed and five open states, in which each closed state could make a direct transition to an open state (two-tiered model) could account for the major features of the single-channel data . Two-tiered models that allowed direct transitions to subconductance open states in addition to the fully open state were also consistent with multiple gateway states . Thus, the gating mechanism of MS(XO) channels differs from the sequential (linear) gating mechanisms considered for MS channels in bacteria, chick skeletal muscle, and Necturus proximal tubule. J Hazard Mater, 2001 Oct 12, 87(1-3), 11 - 21 Toxic effect of sulfur compounds on anaerobic biogranule; Lin CY et al.; The effects of sulfide, sulfite and sulfate on degradation of volatile fatty acid (VFA) in UASB process have been studied by using serum bottle assay and septage-leachate acclimated biogranules . The relative toxicity of the compounds towards methane production and degradation of total VFA varied as SO(4)(2-) -S>S(2-)>SO(3)(2-) -S and SO(4)(2-) -S>SO(3)(2-) -S>S(2-), respectively . The difference of this order shows the importance of choosing monitoring factor in evaluating the effect of sulfur compounds on a UASB system . For the individual VFA the effects of sulfur compounds depended on the types of VFA . The VFA-degrading activity of anaerobic biogranules was decreased by 50% when 34, 26 and 20mg of S(2-), SO(3)(2-) -S and SO(4)(2-) -S were added to each gram of biomass, respectively . A comparison of the toxicity-resistance between two different anaerobic biogranules that acclimatized with septage-leachate mixture and septage was also made.In the presence of the leachate, the toxicity-resistance of biogranules was not weakened to sulfide and sulfate but was enhanced to sulfite. J Biotechnol, 2001 Oct 4, 91(2-3), 127 - 41 Evaluation of plant growth promoting and colonization ability of endophytic diazotrophs from deep water rice; Verma SC et al.; A study of the diversity of endophytic bacteria present in seeds of a deepwater rice variety revealed the presence of seven types of BOX-PCR fingerprints . In order to evaluate the plant growth promoting potential the presence of nitrogenase, indole acetic acid production and mineral phosphate solubilization were estimated in the representative BOX-PCR types . The seven representatives of BOX-PCR types produced indole acetic acid, reduced acetylene and showed specific immunological cross-reaction with anti-dinitrogenase reductase antibody . Only four types showed mineral phosphate solubilizing ability . Comparison of cellulase and pectinase activities showed differences among different BOX-PCR types . PCR fingerprinting data showed that one strain isolated from the surface sterilized seeds as well as the aerial parts of the seedlings of rice variety showed low cellulase and pectinase but relatively high ARA . On the basis of 16S rDNA nucleotide sequence and BIOLOG system of bacterial identification, this strain was identified as Pantoea agglomerans . For studying the endophytic colonization this strain was genetically tagged with the reporter gene, gusA . Histochemical analysis of the seedling grown in hydroponics showed that the tagged strain colonized the root surface, root hairs, root cap, points of lateral root emergence, root cortex and the stelar region . Treatment of the roots with 2,4-D produced short thickened lateral roots which showed better colonization by P . agglomerans. Clin Chim Acta, 2001 Sep 25, 311(2), 119 - 23 Increased serum amylase and lipase in fructose malabsorbers; Ledochowski M et al.; BACKGROUND: Fructose malabsorption is frequently seen in the general population and is characterised by the inability to absorb fructose efficiently . Due to fructose malabsorption, fructose reaches the colon where it is broken down by bacteria to short fatty acids, CO(2) and H(2) . Bloating, cramps, osmotic diarrhea and other symptoms of irritable bowel syndrome are the consequence . We recently found that fructose malabsorption is associated with low plasma folic acid concentrations and low serum tryptophan and zinc . Because fructose malabsorption apparently is associated not only with malabsorption of other nutrients, but also with abdominal discomfort, it was of interest to examine whether mild pancreatitis may be involved . METHODS: We retrospectively examined our data in 159 otherwise healthy adults (110 females, 49 males) aged 14-84 years (mean 45.6+/-14.4 S.D.) with gastrointestinal complaints for serum amylase and serum lipase concentrations . The patients have been tested earlier for fructose malabsorption and lactose maldigestion by measuring breath H(2) concentrations after an oral dose of 25 g fructose and 50 g lactose, respectively, 1 week apart . RESULTS: Fructose malabsorption (H(2) concentrations > or =20 ppm over baseline values) was detected in 107 of 159 individuals (67.3%) . These subjects with fructose malabsorption presented with significantly higher serum amylase concentrations (73.1 U/l+/-25.7 S.D.) compared to individuals with normal fructose absorption (59.6 U/l+17.9 S.D; p=0.0009) . Fructose malabsorbers also presented with higher serum lipase concentrations (122.0 U/l+/-100.3 S.D.) compared to normals (89.5 U/l+/-46.5 S.D.; p<0.05) . To determine whether this finding is a consequence of any sort of malabsorption syndrome or whether it is specific for fructose malabsorption, all subjects were screened for lactose maldigestion . Lactose maldigestion (H(2) concentrations>20 ppm over baseline after lactose loading) was found in 50 of 159 individuals (31.4%) . There were no significant differences in either amylase or lipase concentrations in lactose maldigestors . CONCLUSION: Serum amylase and lipase concentrations are higher in subjects with fructose malabsorption compared to normals . Therefore, fructose malabsorption should be considered as a differential diagnosis in moderately elevated serum amylase. Arch Biochem Biophys, 2001 Oct 1, 394(1), 76 - 86 A role for rubredoxin in oxidative stress protection in Desulfovibrio vulgaris: catalytic electron transfer to rubrerythrin and two-iron superoxide reductase; Coulter ED et al.; Desulfovibrio vulgaris rubredoxin, which contains a single {Fe(SCys)4} site, is shown to be a catalytically competent electron donor to two enzymes from the same organism, namely, rubrerythrin and two-iron superoxide reductase (a.k.a . rubredoxin oxidoreductase or desulfoferrodoxin) . These two enzymes have been implicated in catalytic reduction of hydrogen peroxide and superoxide, respectively, during periods of oxidative stress in D . vulgaris, but their proximal electron donors had not been characterized . We further demonstrate the incorrectness of a previous report that rubredoxin is not an electron donor to the superoxide reductase and describe convenient assays for demonstrating the catalytic competence of all three proteins in their respective functions . Rubrerythrin is shown to be an efficient rubredoxin peroxidase in which the rubedoxin:hydrogen peroxide redox stoichiometry is 2:1 mol:mol . Using spinach ferredoxin-NADP+ oxidoreductase (FNR) as an artificial, but proficient, NADPH:rubredoxin reductase, rubredoxin was further found to catalyze rapid and complete reduction of all Fe3+ to Fe2+ in rubrerythrin by NADPH under anaerobic conditions . The combined system, FNR/rubredoxin/rubrerythrin, was shown to function as a catalytically competent NADPH peroxidase . Another small rubredoxin-like D . vulgaris protein, Rdl, could not substitute for rubredoxin as a peroxidase substrate of rubrerythrin . Similarly, D . vulgaris rubredoxin was demonstrated to efficiently catalyze reduction of D . vulgaris two-iron superoxide reductase and, when combined with FNR, to function as an NADPH:superoxide oxidoreductase . We suggest that, during periods of oxidative stress, rubredoxin could divert electron flow from the electron transport chain of D . vulgaris to rubrerythrin and superoxide reductase, thereby simultaneously protecting autoxidizable redox enzymes and lowering intracellular hydrogen peroxide and superoxide levels . Biochem Biophys Res Commun, 2001 Sep 28, 287(3), 789 - 800 Differences in HAC1 mRNA processing and translation between yeast and mammalian cells indicate divergence of the eukaryotic ER stress response; Bowring CE et al.; Perturbation of normal endoplasmic reticulum (ER) function induces a stress response found throughout eukaryotes, sometimes termed the unfolded protein response (UPR) . In yeast, auxotrophic mutants have identified two genes, IRE1 and HAC1, whose products are key components . Normally HAC1 mRNA is not translated owing to a 252-nt "intron." Disruption of ER function activates Ire1p to remove this intron through endogenous endoribonuclease activity . Together with tRNA ligase, cleavage and splicing produces a translatable HAC1 mRNA to give Hac1p, a transcription factor that upregulates the expression of genes responsive to ER stress . No Hac1p homologue has been identified in mammalian cells, but Ire1p homologues exist with endoribonuclease activity required for a fully functional UPR, raising the possibility that the key features of the yeast UPR might be conserved in higher eukaryotic cells . To address this, we expressed yeast HAC1 in HeLa and HEK 293T human cell lines, both on its own and as fusions with yellow fluorescent protein (YFP) to investigate its processing and translation . HAC1 mRNA was not processed, but efficiently translated irrespective of whether the cells were subjected to ER stress . Expression of exogenous HAC1 mRNA constructs in yeast showed UPR-induced splicing required the presence of its 3' UTR . These results suggest that the mammalian ER stress response has diverged from the yeast UPR . Water Environ Res, 2001 Mar-Apr, 73(2), 223 - 32 pH as a key factor in the competition between glycogen-accumulating organisms and phosphorus-accumulating organisms; Filipe CD et al.; The effects of pH on the anaerobic metabolism of glycogen-accumulating organisms (GAOs) and phosphorus-accumulating organisms (PAOs) were compared using models for the kinetics of acetate uptake . The comparison revealed that GAOs take up acetate faster than PAOs when the pH of the anaerobic zone is less than 7.25, but that PAOs remove acetate faster than GAOs at pHs greater than 7.5 . It was also found that the growth efficiencies of the two organisms are similar . Furthermore, the amount of polyhydroxy-alkanoates available after replenishment of the polymers used during acetate uptake under anaerobic conditions is similar for the two organisms, making GAOs highly competitive in nutrient removal systems . The effects of pH on the competition between the two organisms were demonstrated during the operation of a laboratory-scale sequencing batch reactor . When the overall pH of the system was low, poor phosphate removal was observed . When the pH of the system was allowed to increase to a maximum of 7.5, phosphate removal improved, but was still incomplete . Total removal was only achieved when the pH of the system was never allowed to drop lower than 7.25 . After the minimum pH in the system was increased, total removal of phosphate was achieved in 14 days . The results showed that pH control is a promising strategy for minimizing the accumulation of GAOs and increasing the reliability of biological excess phosphorus removal systems. Water Environ Res, 2001 Mar-Apr, 73(2), 213 - 22 Effects of pH on the rates of aerobic metabolism of phosphate-accumulating and glycogen-accumulating organisms; Filipe CD et al.; The effect of pH on the aerobic metabolism of phosphorus-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) was studied using aerobic batch experiments performed at pH 6.5, 7.0, and 7.5 . For PAOs, the rates of phosphate uptake, polyhydroxy-alkanoates consumption, and biomass growth observed at pH 6.5 were 42, 70, and 53%, respectively, of the rates observed at pH 7.0 . In contrast, the rates for GAOs were relatively independent of pH for the range tested . The results suggest that the stability of biological excess phosphorus removal (BEPR) is strongly dependent on the pH in the aerobic zone . If the pH is low, growth of PAOs will be inhibited whereas the growth of GAOs will be only mildly affected . This may lead to the proliferation of GAOs in BEPR systems, resulting in reduced phosphorus removal. Water Environ Res, 2001 Mar-Apr, 73(2), 154 - 64 Ammonia inhibition in the anaerobic treatment of fishery effluents; Aspe E et al.; Inhibition of the organic matter consumption rate of a saline and rich proteic effluent by free ammonia was assessed in anaerobic filters at 37 degrees C . Inhibition of substrate (total organic carbon, TOC) consumption rate by ammonia was fitted by the Luong and noncompetitive models . Calculated kinetic parameters using the Luong model were maximum specific growth rate, micromax = 0.28 day(-1); average saturation constant, Ks = 568 mg TOC/L; Luong inhibition parameter, KNH3 = 1707mg ammonia-nitrogen (NH3-N)/L; and Luong exponent, gamma = 0.283 and the noncompetitive calculated parameters were umax= 0.26 day(-1), Ks = 703 mg TOC/L, and inhibition parameter, INH3 = 325 mg NH3-N/L . The Luong and noncompetitive models predicted 50% inhibition of the substrate consumption rate at ammonia concentrations of 147 and 325 mg NH3-N/L, respectively, suggesting biomass adaptation to the ammonia concentration (80 mg NH3-N/L as average) at which the anaerobic filters were previously operating . Ammonia formation by anaerobic digestion of fishing effluent would produce a maximum of 65.1 and 58.6% inhibition of the efficiency, predicted by the Luong and noncompetitive models, respectively . Ammonia influence on the digestion steps was determined by comparing fishing effluent with volatile fatty acids as substrates . The noncompetitive model predicted a 50% inhibition of methane production rate at ammonia concentrations of 196.6 and 188.6 mg NH3-N/L for fishing effluent and volatile fatty acids, respectively, suggesting that the methanogenic step is the one most affected by ammonia. Int J Parasitol, 2001 Sep, 31(11), 1166 - 76 Inhibition of apoptosis by intracellular protozoan parasites; Heussler VT et al.; Protozoan parasites which reside inside a host cell avoid direct destruction by the immune system of the host . The infected cell, however, still has the capacity to counteract the invasive pathogen by initiating its own death, a process which is called programmed cell death or apoptosis . Apoptotic cells are recognised and phagocytosed by macrophages and the parasite is potentially eliminated together with the infected cell . This potent defence mechanism of the host cell puts strong selective pressure on the parasites which have, in turn, evolved strategies to modulate the apoptotic program of the host cell to their favour . Within the last decade, the existence of cellular signalling pathways which inhibit the apoptotic machinery has been demonstrated . It is not surprising that intracellular pathogens subvert these pathways to ensure their own survival in the infected cell . Molecular mechanisms which interfere with apoptotic pathways have been studied extensively for viruses and parasitic bacteria, but protozoan parasites have come into focus only recently . Intracellular protozoan parasites which have been reported to inhibit the apoptotic program of the host cell, are Toxoplasma gondii, Trypanosoma cruzi, Leishmania sp., Theileria sp., Cryptosporidium parvum, and the microsporidian Nosema algerae . Although these parasites differ in their mechanism of host cell entry and in their final intracellular localisation, they might activate similar pathways in their host cells to inhibit apoptosis . In this respect, two families of molecules, which are known for their capacity to interrupt the apoptotic program, are currently discussed in the literature . First, the expression of heat shock proteins is often induced upon parasite infection and can directly interfere with molecules of the cellular death machinery . Secondly, a more indirect effect is attributed to the parasite-dependent activation of NF-kappaB, a transcription factor that regulates the transcription of anti-apoptotic molecules. Mem Inst Oswaldo Cruz, 2001 Aug, 96(6), 865 - 73 A new continuous cell line from the mosquito Psorophora confinnis (Diptera: Culicidae) and its susceptibility to infections with some arboviruses; Bello FJ et al.; A new cell line, PC-0199-BR, was established from embryonated eggs of the mosquito Psorophora confinnis . To date (September 2000) it has had 62 continuous passages . This is the first report of a cell line of mosquitoes belonging to the genus Psorophora . Cell growth initially was achieved in the MM/VP12 medium, supplemented with 20% fetal bovine serum; however, the subcultures were later adapted to Grace's medium with 10% fetal bovine serum . Cell morphology in the primary cultures was heterogeneous; but later in the established cell line, the predominant cell type was epithelioid . Cultured cells were predominantly diploid (2n=6); however, chromosome abnormalities were observed in a small proportion of the cells in later passages . C and G band patterns were also determined in the karyotype . The cell line isozyme profiles coincided with pupae and adult samples of the species taken from the same colony . A preliminary arbovirus susceptibility study for the cell line was undertaken . No evidence was observed of contamination of the cell line with bacteria, fungi or mycoplasma. J Biol Chem, 2001 Nov 16, 276(46), 43152 - 9 Epub 2001 Sep 18. Structural determinants of Ca2+ transport in the Arabidopsis H+/Ca2+ antiporter CAX1; Shigaki T et al.; Ca(2+) levels in plants, fungi, and bacteria are controlled in part by H(+)/Ca(2+) exchangers; however, the relationship between primary sequence and biological activity of these transporters has not been reported . The Arabidopsis H(+)/cation exchangers, CAX1 and CAX2, were identified by their ability to suppress yeast mutants defective in vacuolar Ca(2+) transport . CAX1 has a much higher capacity for Ca(2+) transport than CAX2 . An Arabidopsis thaliana homolog of CAX1, CAX3, is 77% identical (93% similar) and, when expressed in yeast, localized to the vacuole but did not suppress yeast mutants defective in vacuolar Ca(2+) transport . Chimeric constructs and site-directed mutagenesis showed that CAX3 could suppress yeast vacuolar Ca(2+) transport mutants if a nine-amino acid region of CAX1 was inserted into CAX3 (CAX3-9) . Biochemical analysis in yeast showed CAX3-9 had 36% of the H(+)/Ca(2+) exchange activity as compared with CAX1; however, CAX3-9 and CAX1 appear to differ in their transport of other ions . Exchanging the nine-amino acid region of CAX1 into CAX2 doubled yeast vacuolar Ca(2+) transport but did not appear to alter the transport of other ions . This nine-amino acid region is highly variable among the plant CAX-like transporters . These findings suggest that this region is involved in CAX-mediated Ca(2+) specificity. Curr Pharm Des, 2001 Nov, 7(17), 1839 - 62 Peptide-nucleic acids (PNAs): a tool for the development of gene expression modifiers; Gambari R; Peptide nucleic acids (PNAs) represent nucleic acid analogues with unique biochemical properties and of great interest for the development of therapeutic agents . The firstly designed and tested PNAs are molecules in which the sugar-phosphate backbone of DNA was replaced with a pseudopeptide chain constituted by N-(2-aminoethyl) glycine monomers . Nucleobases can be linked to this backbone through a carboxymethyl moiety, which allows to maintain a two atom spacer between the backbone and the bases . Since the first reports on PNAs based on N-(2-aminoethyl) glycine backbone, other PNA analogues have been synthesized, with the main purpose of improve biological activities as well as stability and efficient delivery to target cells . Of great interest are chiral PNAs, PNA analogues bearing phosphate groups (PHONA), PNA-DNA and PNA-peptide chimeras, PNA linked to non-peptide vectors . PNAs hybridize to DNA and RNA with high efficiency following the Watson-Crick hybridization rules, forming highly stable PNA/DNA and PNA/RNA duplexes . In addition, homopyrimidine PNAs, as well as PNAs containing a high pyrimidine:purine ratio, are able to bind to DNA or RNA forming highly stable (PNA)(2)-DNA triple helices . Accordingly, therapeutic PNA and PNA analogues could act as antigene as well as antisense molecules . In addition, recent studies provide evidences for the possible use of PNA-based therapeutic molecules as artificial promoters, as decoy or ribozyme facilitator . Among the therapeutic applications of PNA-based molecules, the most pomising include anti-cancer and anti-viral experimental strategies, but activity of PNAs against bacteria and medically important parasitic organisms have been also reported. Biochemistry, 2001 Sep 25, 40(38), 11472 - 82 Pigment organization and their interactions in reaction centers of photosystem II: optical spectroscopy at 6 K of reaction centers with modified pheophytin composition; Germano M et al.; Photosystem II reaction centers (RC) with selectively exchanged pheophytin (Pheo) molecules as described in {Germano, M., Shkuropatov, A . Ya., Permentier, H., Khatypov, R . A., Shuvalov, V . A., Hoff, A . J., and van Gorkom, H . J . (2000) Photosynth . Res . 64, 189-198} were studied by low-temperature absorption, linear and circular dichroism, and triplet-minus-singlet absorption-difference spectroscopy . The ratio of extinction coefficients epsilon(Pheo)/epsilon(Chl) for Q(Y) absorption in the RC is approximately 0.40 at 6 K and approximately 0.45 at room temperature . The presence of 2 beta-carotenes, one parallel and one perpendicular to the membrane plane, is confirmed . Absorption at 670 nm is due to the perpendicular Q(Y) transitions of the two peripheral chlorophylls (Chl) and not to either Pheo . The "core" pigments, two Pheo and four Chl absorb in the 676-685 nm range . Delocalized excited states as predicted by the "multimer model" are seen in the active branch . The inactive Pheo and the nearby Chl, however, mainly contribute localized transitions at 676 and 680 nm, respectively, although large CD changes indicate that exciton interactions are present on both branches . Replacement of the active Pheo prevents triplet formation, causes an LD increase at 676 and 681 nm, a blue-shift of 680 nm absorbance, and a bleach of the 685 nm exciton band . The triplet state is mainly localized on the Chl corresponding to B(A) in purple bacteria . Both Pheo Q(Y) transitions are oriented out of the membrane plane . Their Q(X) transitions are parallel to that plane, so that the Pheos in PSII are structurally similar to their homologues in purple bacteria. Biochemistry, 2001 Sep 25, 40(38), 11460 - 71 Light-induced proton release and proton uptake reactions in the cyanobacterial phytochrome Cph1; van Thor JJ et al.; The P(r) to P(fr) transition of recombinant Synechocystis PCC 6803 phytochrome Cph1 and its N-terminal sensor domain Cph1Delta2 is accompanied by net acidification in unbuffered solution . The extent of this net photoreversible proton release was measured with a conventional pH electrode and increased from less than 0.1 proton released per P(fr) formed at pH 9 to between 0.6 (Cph1) and 1.1 (Cph1Delta2) H(+)/P(fr) at pH 6 . The kinetics of the proton release were monitored at pH 7 and pH 8 using flash-induced transient absorption measurements with the pH indicator dye fluorescein . Proton release occurs with time constants of approximately 4 and approximately 20 ms that were also observed in parallel measurements of the photocycle (tau(3) and tau(4)) . The number of transiently released protons per P(fr) formed is about one . This H(+) release phase is followed by a proton uptake phase of a smaller amplitude that has a time constant of approximately 270 ms (tau(5)) and is synchronous with the formation of P(fr) . The acidification observed in the P(r) to P(fr) transition with pH electrodes is the net effect of these two sequential protonation changes . Flash-induced transient absorption measurements were carried out with Cph1 and Cph1Delta2 at pH 7 and pH 8 . Global analysis indicated the presence of five kinetic components (tau(1)-tau(5): 5 and 300 micros and 3, 30, and 300 ms) . Whereas the time constants were approximately pH independent, the corresponding amplitude spectra (B(1), B(3), and B(5)) showed significant pH dependence . Measurements of the P(r)/P(fr) photoequilibrium indicated that it is pH independent in the range of 6.5-9.0 . Analysis of the pH dependence of the absorption spectra from 6.5 to 9.0 suggested that the phycocyanobilin chromophore deprotonates at alkaline pH in both P(r) and P(fr) with an approximate pK(a) of 9.5 . The protonation state of the chromophore at neutral pH is therefore the same in both P(r) and P(fr) . The light-induced deprotonation and reprotonation of Cph1 at neutral pH are thus due to pK(a) changes in the protein moiety, which are linked to conformational transitions occurring around 4 and 270 ms after photoexcitation . These transient structural changes may be relevant for signal transduction by this cyanobacterial phytochrome. Exp Parasitol, 2001 Aug, 98(4), 171 - 9 Encephalitozoon cuniculi (Microspora): characterization of a phospholipid metabolic pathway potentially linked to therapeutics; El Alaoui H et al.; Phospholipid metabolism of the microsporidian Encephalitozoon cuniculi, an obligate intracellular parasite, has been investigated . Labeled precursor incorporation experiments have shown that phosphatidylserine decarboxylase and phosphatidylethanolamine N-methyltransferase are more active in cells infected by E . cuniculi than in uninfected cells . In contrast, no difference was observed in the activity of Kennedy pathway's enzymes, the mammalian pathway . This suggests the occurrence in microsporidia of a bacteria- and fungi-typical pathway for phospholipid synthesis, which is supported by the identification of two genes implicated in this pathway, the cds gene encoding the key enzyme CDP-diacylglycerol synthase (E.C . 2.7.7.41) and the pss gene for CDP-alcohol phosphatidyltransferase . The pss gene could encode phosphatidylserine synthase (E.C . 2.7.8.8.), which catalyses the de novo synthesis of phosphatidylserine in bacteria and fungi . The complete CDP-diacylglycerol synthase messenger has been isolated and shows very short 5' and 3' untranslated regions . This is strong evidence for the functionality of a metabolic pathway which could be a potential target against microsporidia which infect humans . Biofizika, 2001 Jul-Aug, 46(4), 656 - 60 {Model of dynamics of the insect cellular immune system}; Nedorezov LV et al.; A mathematical model for the dynamics of functioning of an insect immune subsystem is considered . It is assumed that the interaction between hemocytes and bacteria corresponds to the Volterra principle of "pair interactions": the rate at which bacteria enter the system decreases in proportion to the rate of interaction of hemocytes with bacteria . In the absence of interaction, the intrinsic dynamics of bacteria is described by the Malthus law . Dynamic regimes of the model for different values of the parameters were analyzed . In particular, it was shown that, depending on the initial values of variables and the values of the parameters, there exist two regimes, the regime of death of the organism and the regime of elimination of bacteria. Water Environ Res, 2001 Jan-Feb, 73(1), 118 - 26 Biological sulfate reduction using molasses as a carbon source; Annachhatre AP et al.; The feasibility of using a laboratory-scale upflow anaerobic sludge blanket process for sulfate reduction with molasses as a carbon source was demonstrated . Competition between methane-producing bacteria (MPB) and sulfate-reducing bacteria (SRB) was influenced by the chemical oxygen demand-to-sulfur (COD:S) ratio in the feed . Sulfate removal greater than 80% could be achieved at COD:S greater than 10 when MPB predominated . Activity of MPB and SRB was inhibited at a dissolved sulfide concentration of approximately 200 mg/L . Competition between MPB and SRB was intense as the COD:S was reduced from 5 to 2 . Further reduction in the COD:S to 0.7 led to the formation of sulfidogenic granules . The COD removal decreased to approximately 30% at a COD:S less than 2 because of accumulation of sulfurous precipitates and the nonbiodegradable portion of molasses in the sludge . Reduced gas production rates further imposed limitations on diffusion of the organic substrate into granules . Sulfidogenic process operation yielded sulfate removal as great as 70% at a COD:S of approximately 3.5. Water Environ Res, 2001 Jan-Feb, 73(1), 103 - 9 Anaerobic treatment of condensates: trial at a kraft pulp and paper mill; Dufresne R et al.; The Domtar Papers pulp and paper mill in Windsor, Quebec, Canada, investigated the potential for anaerobic treatment of contaminated kraft mill condensates . The objectives of this project were to assess the technical feasibility of replacing the steam stripper with anaerobic treatment, to provide basic information for the design of an anaerobic treatment process for condensates, and to provide information on treated condensate quality for eventual reuse . The project involved extensive chemical characterization of condensates, followed by treatability tests . The tests included laboratory bench-scale tests and on-site pilot testing using direct feed from the process . Characterization showed that the organic content of the condensates was essentially methanol, as expected, but that foul evaporator condensates had high sulfide contents . It was found that undiluted foul condensates at the Windsor mill are toxic to the anaerobic biomass because of these high concentrations of sulfides . Treatment of combined condensates is possible at an approximate volumetric loading of 10 to 12 g/L.d chemical oxygen demand (COD) with good production of biogas (0.35 L/g of COD removed) and excellent methanol removal (better than 95%) . The biogas produced is of excellent fuel quality with close to 90% methane, but with a high sulfide content (close to 4%). Mikrobiologiia, 2001 Jul-Aug, 70(4), 444 - 51 {Growth of mesophilic methanotrophs at low temperatures}; Kevbrina MV et al.; The optimal growth of mesophilic methanotrophic bacteria (collection strains of the genera Methylocystis, Methylomonas, Methylosinus, and Methylobacter) occurred within temperature ranges of 31-34 degrees C and 23-25 degrees C . None of the strains studied were able to grow at 1.5 or 4 degrees C . Representatives of six methanotrophic species (strains Mcs . echinoides 2, Mm . methanica 12, Mb . bovis 89, Mcs . pyriformis 14, Mb . chroococcum 90, and Mb . vinelandii 87) could grow at 10 degrees C (with a low specific growth rate) . The results obtained suggest that some mesophilic methane-oxidizing bacteria display psychrotolerant (psychrotrophic) but not psychrophilic properties . In general, the Rosso model, which describes bacterial growth rate as a function of temperature, fits well the experimental data, although, for most methanotrophs, with symmetrical approximations for optimal temperature. Aust Fam Physician, 2001 Jul, 30(7), 681 - 4 Herbal medicine in infectious disease; Pinn G; This eighth article in the series looks at the current role of plant therapy in infection . Plant chemicals are useful for infection control and, until the advent of antibiotics (many themselves of natural origin) were the only remedies available . The current role of plants in this area could be summarised as treating minor acute infections, topical therapy for skin or wound infections and perhaps a supportive role in chronic infection . With increasing resistance of bacteria, viruses and malaria to standard therapy, alternative treatments are being re-explored with some urgency. Nature, 2001 Sep 13, 413(6852), 211 - 8 How the olfactory system makes sense of scents; Firestein S; The human nose is often considered something of a luxury, but in the rest of the animal world, from bacteria to mammals, detecting chemicals in the environment has been critical to the successful organism . An indication of the importance of olfactory systems is the significant proportion - as much as 4% - of the genomes of many higher eukaryotes that is devoted to encoding the proteins of smell . Growing interest in the detection of diverse compounds at single-molecule levels has made the olfactory system an important system for biological modelling. Nature, 2001 Sep 13, 413(6852), 128 - 9 Nitrogen fixation . Endocrine disrupters and flavonoid signalling; Fox JE et al.; Nitrogen fixation is a symbiotic process initiated by chemical signals from legumes that are recognized by soil bacteria . Here we show that some endocrine-disrupting chemicals (EDCs), so called because of their effect on hormone-signalling pathways in animal cells, also interfere with the symbiotic signalling that leads to nitrogen fixation . Our results raise the possibility that these phytochemically activated pathways may have features in common with hormonal signalling in vertebrates, thereby extending the biological and ecological impact of EDCs. Science, 2001 Oct 26, 294(5543), 818 - 23 Epub 2001 Sep 13. Biogeography and ecological setting of Indian Ocean hydrothermal vents; Van Dover CL et al.; Within the endemic invertebrate faunas of hydrothermal vents, five biogeographic provinces are recognized . Invertebrates at two Indian Ocean vent fields (Kairei and Edmond) belong to a sixth province, despite ecological settings and invertebrate-bacterial symbioses similar to those of both western Pacific and Atlantic vents . Most organisms found at these Indian Ocean vent fields have evolutionary affinities with western Pacific vent faunas, but a shrimp that ecologically dominates Indian Ocean vents closely resembles its Mid-Atlantic counterpart . These findings contribute to a global assessment of the biogeography of chemosynthetic faunas and indicate that the Indian Ocean vent community follows asymmetric assembly rules biased toward Pacific evolutionary alliances. Mol Biol Evol, 2001 Oct, 18(10), 1919 - 28 Mitochondrial type iron-sulfur cluster assembly in the amitochondriate eukaryotes Trichomonas vaginalis and Giardia intestinalis, as indicated by the phylogeny of IscS; Tachezy J et al.; Pyridoxal-5'-phosphate-dependent cysteine desulfurase (IscS) is an essential enzyme in the assembly of FeS clusters in bacteria as well as in the mitochondria of eukaryotes . Although FeS proteins are particularly important for the energy metabolism of amitochondrial anaerobic eukaryotes, there is no information about FeS cluster formation in these organisms . We identified and sequenced two IscS homologs of Trichomonas vaginalis (TviscS-1 and TviscS-2) and one of Giardia intestinalis (GiiscS) . TviscS-1, TviscS-2, and GiiscS possess the typical conserved regions implicated in cysteine desulfurase activity . N-termini of TviscS-1 and TviscS-2 possess eight amino acid extensions, which resemble the N-terminal presequences that target proteins to hydrogenosomes in trichomonads . No presequence was evident in GiiscS from Giardia, an organism that apparently lacks hydrogenosmes or mitochondria . Phylogenetic analysis showed a close relationship among all eukaryotic IscS genes including those of amitochondriates . IscS of proteobacteria formed a sister group to the eukaryotic clade, suggesting that isc-related genes were present in the proteobacterial endosymbiotic ancestor of mitochondria and hydrogenosomes . NifS genes of nitrogen-fixing bacteria, which are IscS homologs required for specific formation of FeS clusters in nitrogenase, formed a more distant group . The phylogeny indicates the presence of a common mechanism for FeS cluster formation in mitochondriates as well as in amitochondriate eukaryotes . Furthermore, the analyses support a common origin of Trichomonas hydrogenosomes and mitochondria, as well as secondary loss of mitochondrion/hydrogenosome-like organelles in Giardia. Phytochemistry, 2001 Oct, 58(3), 441 - 9 Isolation, characterization, and systematic significance of 2-pyrone-4,6-dicarboxylic acid in Rosaceae; Wilkes S et al.; 2-Pyrone-4,6-dicarboxylic acid was isolated from Potentilla anserina . Until now this substance was only found in bacteria and not in higher plants . By sterile cultivation it was verified that this compound is genuine also in plants . In addition the systematic relevance of 2-pyrone-4,6-dicarboxylic acid within the Rosaceae was tested . The compound seems to be a chemotaxonomic marker for the Rosoideae sensu stricto proposed by Morgan et al . (Morgan, D.R., Soltis, D.E., Robertson, K.R., 1994 . Systematic and evolutionary implications of rbcL sequence variation in Rosaceae . American Journal of Botany 81, 890-903). Brain Pathol, 2001 Oct, 11(4), 452 - 64 Polymerase chain reaction as a diagnostic adjunct in herpesvirus infections of the nervous system; Kleinschmidt-DeMasters BK et al.; Polymerase chain reaction (PCR) is a powerful technique that allows detection of minute quantities of DNA or RNA in cerebrospinal fluid (CSF), vesicle and endoneurial fluids, blood, fresh-frozen, and even formalin-fixed tissues . Various infectious agents can be detected with high specificity and sensitivity, including bacteria, parasites, rickettsia and viruses . PCR analysis of CSF has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses (HHV), and has now replaced brain biopsy as the gold standard for diagnosis of herpes simplex virus (HSV) encephalitis . PCR analysis of both CSF and nervous system tissues has also broadened our understanding of the spectrum of disease caused by HSV-1 and -2, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), and HHV-6 . Nonetheless, positive tissue PCR results must be interpreted cautiously, especially in cases that lack corroborating clinical and neuropathologic evidence of infection . Moreover, positive PCR results from tissues do not distinguish latent from productive (lytic) viral infections . In several neurological diseases, negative PCR results have provided strong evidence against a role for herpesviruses as the causative agents . This review focuses on the use of PCR tests to diagnose HSV and VZV infections of the nervous system. Vox Sang, 2001, 81(2), 87 - 92 Granulocyte transfusion: a review; Yeghen T et al.; Neutrophils are the body's main defence against invasion by bacteria and fungi and, below a level of 1 x 10(9)/l, there is a direct relationship between their circulating number and the risk of systemic infection . Despite advances in supportive care, such as improved broad-spectrum antibiotics and the haemopoietic growth factors, neutropenia following myelosuppressive chemotherapy for malignant disease remains the most important cause of treatment-related morbidity and mortality and its most important dose-limiting toxicity . Although there is clear theoretical, experimental and anecdotal clinical evidence supporting the use of transfused granulocytes to prevent and treat infection in neutropenia, early attempts at exploiting this clinically were unsuccessful, mainly because of difficulties in collecting a sufficient number of cells . Improvements in the technology of collection, including the use of red cell sedimenting agents, glucocorticoids and, more recently, granulocyte-colony-stimulating factor, now allow granulocyte doses within the therapeutic range to be routinely collected . Preliminary evidence suggests clinical efficacy . However, well-designed trials with clinically relevant end-points will be required before granulocyte transfusion can become part of routine clinical practice. Mol Microbiol, 2001 Sep, 41(5), 1077 - 89 SREA is involved in regulation of siderophore biosynthesis, utilization and uptake in Aspergillus nidulans; Oberegger H et al.; Under conditions of low iron availability, most fungi excrete siderophores in order to mobilize extracellular iron . We show that lack of the GATA-type transcription factor SREA in Aspergillus nidulans not only leads to derepression of siderophore biosynthesis but also to deregulation of siderophore-bound iron uptake and ornithine esterase expression . Furthermore, SREA deficiency causes increased accumulation of ferricrocin, the siderophore responsible for intracellular iron storage . In sreA deletion strains, extracellular siderophore production is derepressed but still regulated negatively by iron availability, indicating the presence of an additional iron-regulatory mechanism . In contrast, iron affects ferricrocin accumulation in a positive way, suggesting a protective role for this siderophore in detoxification of intracellular iron excess . The harmfulness of deregulated iron uptake in this mutant is demonstrated by increased expression of genes encoding the antioxidative enzymes catalase CATB and the superoxide dismutases SODA and SODB . It is noteworthy that iron starvation was found to repress catB expression in wild-type (wt) and SREA-deficient strains, consistent with catB being subject to SREA-independent iron regulation . Differential display led to the identification of putative SREA target genes amcA and mirA . The deduced MIRA amino acid sequence displays significant similarity to recently characterized siderophore permeases of Saccharomyces cerevisiae . amcA encodes a putative mitochondrial carrier for the siderophore precursor ornithine, indicating cross-regulation of siderophore and ornithine metabolism. Mol Ecol, 2001 Aug, 10(8), 2101 - 6 Wolbachia infection shared among planthoppers (Homoptera: Delphacidae) and their endoparasite (Strepsiptera: Elenchidae): a probable case of interspecies transmission; Noda H et al.; Wolbachia, a group of parasitic bacteria of arthropods, are believed to be horizontally transmitted among arthropod taxa . We present a new probable example of interspecies horizontal transmission of Wolbachia by way of an endoparasite based on the conformity of Wolbachia gene sequences . Field samples of two rice planthoppers, Laodelphax striatellus and Sogatella furcifera possessed identical Wolbachia . Among three major endoparasites of planthoppers, a strepsipteran, Elenchus japonicus, harboured the identical Wolbachia strain, suggesting strepsipteran transmission of Wolbachia from one planthopper to the other . No Wolbachia was detected in a mermithid nematode Agamermis unka, and dryinid wasps possessed different types of Wolbachia. J Oral Pathol Med, 2001 Oct, 30(9), 560 - 3 Helicobacter pylori colonization of tongue mucosa--increased incidence in atrophic glossitis and burning mouth syndrome (BMS); Gall-Troselj K et al.; Nested polymerase chain reaction (PCR) was performed to detect the presence of Helicobacter pylori in tongue mucosa in 268 patients divided into four groups according to their diagnosis: 87 with atrophic glossitis, 37 with benign migratory glossitis and 144 with burning mouth syndrome (BMS) . The latter group was subdivided according to anatomic site of burning sensation: subgroup A (54 patients) with complaints limited to tongue and subgroup B (90 patients) with burning sensations in other parts of oral mucosa . H . pylori was found in 43 samples (16%) . Bacteria were significantly less present in tongue mucosa affected with benign migratory glossitis compared with atrophic glossitis and BMS (P=0.025) . This difference was more obvious when compared with atrophic glossitis only (P=0.006) . Mucosal changes in these conditions might make the oral environment more acceptable for H . pylori colonization compared with normal mucosa, and this mechanism may play a role in its oro-oral transmission. Anal Biochem, 2001 Sep 15, 296(2), 162 - 6 Pellet pestle homogenization of agarose gel slices at 45 degrees C for deoxyribonucleic acid extraction; Kurien BT et al.; A simple method for extracting DNA from agarose gel slices is described . The extraction is rapid and does not involve harsh chemicals or sophisticated equipment . The method involves homogenization of the excised gel slice (in Tris-EDTA buffer), containing the DNA fragment of interest, at 45 degrees C in a microcentrifuge tube with a Kontes pellet pestle for 1 min . The "homogenate" is then centrifuged for 30 s and the supernatant is saved . The "homogenized" agarose is extracted one more time and the supernatant obtained is combined with the previous supernatant . The DNA extracted using this method lent itself to restriction enzyme analysis, ligation, transformation, and expression of functional protein in bacteria . This method was found to be applicable with 0.8, 1.0, and 2.0% agarose gels . DNA fragments varying from 23 to 0.4 kb were extracted using this procedure and a yield ranging from 40 to 90% was obtained . The yield was higher for fragments 2.0 kb and higher (70-90%) . This range of efficiency was maintained when the starting material was kept between 10 and 300 ng . The heat step was found to be critical since homogenization at room temperature failed to yield any DNA . Extracting DNA with our method elicited an increased yield (up to twofold) compared with that extracted with a commercial kit . Also, the number of transformants obtained using the DNA extracted with our method was at least twice that obtained using the DNA extracted with the commercial kit . Infect Immun, 2001 Oct, 69(10), 6541 - 4 Mouse cytokine profiles associated with Brucella abortus RB51 vaccination or B . abortus 2308 infection; Pasquali P et al.; This study indicated that mice immunized with Brucella abortus RB51 bacteria and subsequently challenged with B . abortus 2308 were protected from reinfection . After vaccination, both Th1 and Th2 cytokine patterns were observed . Of those, the early production of gamma interferon seems to have the prominent role in inducing an immunologically based protection. Infect Immun, 2001 Oct, 69(10), 6427 - 33 Bartonella henselae-specific cell-mediated immune responses display a predominantly Th1 phenotype in experimentally infected C57BL/6 mice; Arvand M et al.; Immune responses of the immunocompetent host to Bartonella henselae infection were investigated in the murine infection model using C57BL/6 mice . Following intraperitoneal infection with human-derived B . henselae strain Berlin-1, viable bacteria could be recovered from livers and spleens during the first week postinfection, while Bartonella DNA remained detectable by PCR in the liver for up to 12 weeks after infection . Granulomatous lesions developed in livers of infected mice, reached maximal density at 12 weeks after infection, and persisted for up to 20 weeks, indicating that B . henselae induced a chronic granulomatous hepatitis in the immunocompetent murine host . T-cell-mediated immune responses were analyzed in vitro by means of spleen cell proliferation and cytokine release assays as well as analysis of immunoglobulin G (IgG) isotypes . Spleen cells from infected mice proliferated specifically upon stimulation with heat-killed Bartonella antigen . Proliferative responses were mainly mediated by CD4+ T cells, increased during the course of infection, peaked at 8 weeks postinfection, and decreased thereafter . Gamma interferon, but not interleukin-4, was produced in vitro by spleen cells from infected animals upon stimulation with Bartonella antigens . Bartonella-specific IgG was detectable in serum of infected mice by 2 weeks, and the antibody concentration peaked at 12 weeks postinfection . IgG2b was the prominent isotype among the Bartonella-specific serum IgG antibodies . These data indicate that B . henselae induces cell-mediated immune responses with a Th1 phenotype in immunocompetent C57BL/6 mice. Infect Immun, 2001 Oct, 69(10), 6348 - 63 High extracellular levels of Mycobacterium tuberculosis glutamine synthetase and superoxide dismutase in actively growing cultures are due to high expression and extracellular stability rather than to a protein-specific export mechanism; Tullius MV et al.; Glutamine synthetase (GS) and superoxide dismutase (SOD), large multimeric enzymes that are thought to play important roles in the pathogenicity of Mycobacterium tuberculosis, are among the bacterium's major culture filtrate proteins in actively growing cultures . Although these proteins lack a leader peptide, their presence in the extracellular medium during early stages of growth suggested that they might be actively secreted . To understand their mechanism of export, we cloned the homologous genes (glnA1 and sodA) from the rapid-growing, nonpathogenic Mycobacterium smegmatis, generated glnA1 and sodA mutants of M . smegmatis by allelic exchange, and quantitated expression and export of both mycobacterial and nonmycobacterial GSs and SODs in these mutants . We also quantitated expression and export of homologous and heterologous SODs from M . tuberculosis . When each of the genes was expressed from a multicopy plasmid, M . smegmatis exported comparable proportions of both the M . tuberculosis and M . smegmatis GSs (in the glnA1 strain) or SODs (in the sodA strain), in contrast to previous observations in wild-type strains . Surprisingly, recombinant M . smegmatis and M . tuberculosis strains even exported nonmycobacterial SODs . To determine the extent to which export of these large, leaderless proteins is expression dependent, we constructed a recombinant M . tuberculosis strain expressing green fluorescent protein (GFP) at high levels and a recombinant M . smegmatis strain coexpressing the M . smegmatis GS, M . smegmatis SOD, and M . tuberculosis BfrB (bacterioferritin) at high levels . The recombinant M . tuberculosis strain exported GFP even in early stages of growth and at proportions very similar to those of the endogenous M . tuberculosis GS and SOD . Similarly, the recombinant M . smegmatis strain exported bacterioferritin, a large (approximately 500-kDa), leaderless, multimeric protein, in proportions comparable to GS and SOD . In contrast, high-level expression of the large, leaderless, multimeric protein malate dehydrogenase did not lead to extracellular accumulation because the protein was highly unstable extracellularly . These findings indicate that, contrary to expectations, export of M . tuberculosis GS and SOD in actively growing cultures is not due to a protein-specific export mechanism, but rather to bacterial leakage or autolysis, and that the extracellular abundance of these enzymes is simply due to their high level of expression and extracellular stability . The same determinants likely explain the presence of other leaderless proteins in the extracellular medium of actively growing M . tuberculosis cultures. Infect Immun, 2001 Oct, 69(10), 6131 - 9 Mannheimia haemolytica leukotoxin activates a nonreceptor tyrosine kinase signaling cascade in bovine leukocytes, which induces biological effects; Jeyaseelan S et al.; The leukotoxin (LktA) produced by Mannheimia haemolytica binds to bovine lymphocyte function-associated antigen 1 (LFA-1) and induces biological effects in bovine leukocytes in a cellular and species-specific fashion . We have previously shown that LktA also binds to porcine LFA-1 without eliciting any effects . These findings suggest that the specificity of LktA effects must entail both binding to LFA-1 and activation of signaling pathways which are present in bovine leukocytes . However, the signaling pathways leading to biological effects upon LktA binding to LFA-1 have not been characterized . In this context, several reports have indicated that ligand binding to LFA-1 results in activation of a nonreceptor tyrosine kinase (NRTK) signaling cascade . We designed experiments with the following objectives: (i) to determine whether LktA binding to LFA-1 leads to activation of NRTKs, (ii) to examine whether LktA-induced NRTK activation is target cell specific, and (iii) to determine whether LktA-induced NRTK activation is required for biological effects . We used a biologically inactive mutant leukotoxin (DeltaLktA) for comparison with LktA . Our results indicate that LktA induces tyrosine phosphorylation (TP) of the CD18 tail of LFA-1 in bovine leukocytes . The DeltaLktA mutant does not induce TP of the CD18 tail, albeit binding to bovine LFA-1 . LktA-induced TP of the CD18 tail was attenuated by an NRTK inhibitor, herbimycin A; a phosphatidylinositol 3'-kinase (PI 3-kinase) inhibitor, wortmannin; and a Src kinase inhibitor, PP2, in a concentration-dependent manner . Furthermore, LktA induces TP of the CD18 tail in bovine, but not porcine, leukocytes . Moreover, LktA-induced intracellular calcium ({Ca2+}i) elevation was also inhibited by herbimycin A, wortmannin, and PP2 . Thus, our data represent the first evidence that binding of LktA to bovine LFA-1 induces a species-specific NRTK signaling cascade involving PI 3-kinase and Src kinases and that this signaling cascade is required for LktA-induced biological effects. Infect Immun, 2001 Oct, 69(10), 6038 - 43 Role of ADP-ribosyltransferase activity of pertussis toxin in toxin-adhesin redundancy with filamentous hemagglutinin during Bordetella pertussis infection; Alonso S et al.; Pertussis toxin (PT) and filamentous hemagglutinin (FHA) are two major virulence factors of Bordetella pertussis . FHA is the main adhesin, whereas PT is a toxin with an A-B structure, in which the A protomer expresses ADP-ribosyltransferase activity and the B moiety is responsible for binding to the target cells . Here, we show redundancy of FHA and PT during infection . Whereas PT-deficient and FHA-deficient mutants colonized the mouse respiratory tract nearly as efficiently as did the isogenic parent strain, a mutant deficient for both factors colonized substantially less well . This was not due to redundant functions of PT and FHA as adhesins, since in vitro studies of epithelial cells and macrophages indicated that FHA, but not PT, acts as an adhesin . An FHA-deficient B . pertussis strain producing enzymatically inactive PT colonized as poorly as did the FHA-deficient, PT-deficient strain, indicating that the ADP-ribosyltransferase activity of PT is required for redundancy with FHA . Only strains producing active PT induced a local transient release of tumor necrosis factor alpha (TNF-alpha), suggesting that the pharmacological effects of PT are the basis of the redundancy with FHA, through the release of TNF-alpha . This may lead to damage of the pulmonary epithelium, allowing the bacteria to colonize even in the absence of FHA. Vet Immunol Immunopathol, 2001 Sep 20, 81(3-4), 251 - 4 The ACVD task force on canine atopic dermatitis (XIII): threshold phenomenon and summation of effects; Marsella R et al.; The concepts of a threshold for pruritus and a threshold for canine atopic dermatitis (AD) are useful in the understanding of the development of clinical manifestations of this disease . Multiple flare factors, such as infections with bacteria and yeasts, can contribute to the severity of clinical signs in affected patients. Environ Microbiol, 2001 Jul, 3(7), 460 - 70 Evidence for anaerobic syntrophic acetate oxidation during methane production in the profundal sediment of subtropical Lake Kinneret (Israel); Nusslein B et al.; Methane production was measured in samples of the profundal sediment from Lake Kinneret . Production rates of CH(4) were higher at 30 degrees C than at the in situ temperature of 15 degrees C and were higher in the top 5 cm layer than below . Turnover of {2-(14)C}-acetate resulted in the production of (14)CH(4) and (14)CO(2) with turnover times of < 42 min . However, < 30% of the added radioactivity was converted to gaseous products, indicating that only part of the acetate pool was microbially available . The calculated acetate turnover rates were sufficient to account for total CH(4) production, indicating that CH(4) was produced exclusively from acetate . This conclusion was confirmed by inhibition of methanogens with chloroform, which resulted in an almost stoichiometric accumulation of acetate . However, a large percentage (30-60%) of {2-(14)C}-acetate was converted to (14)CO(2), despite lack of reducible sulphate or other oxidants in the sediment . Anoxic preincubation of the sediment did not result in reduced production of (14)CO(2) . Therefore, part of the acetate must have been oxidized rather than methanogenically cleaved . Conversion of {(14)C}-bicarbonate to (14)CH(4) indicated that 30-50% of total CH(4) production originated from reduction of CO(2) . To reconcile the relatively high contribution of H(2)/CO(2)-dependent methanogenesis with the relatively high oxidative conversion of acetate, we assume that part of the acetate was used syntrophically by consortia of acetate-oxidizing bacteria and H(2)/CO(2)-using methanogens . This conclusion is supported by favourable thermodynamic conditions for syntrophic acetate oxidation under in situ conditions and complete inhibition of {2-(14)C}-acetate turnover at high H(2) partial pressures . Further evidence to support this conclusion comes from the analysis of the structure of the archaeal community . Terminal restriction fragment length polymorphism (T-RFLP) and partial sequence analysis of the SSU rRNA genes amplified from DNA extracts of the sediment showed Methanomicrobiaceae as the dominant methanogenic group, whereas acetoclastic methanogens could not be detected. Cell Microbiol, 2001 Sep, 3(9), 623 - 32 Evidence of a leading role for VEGF in Bartonella henselae-induced endothelial cell proliferations; Kempf VA et al.; Bartonella henselae causes the vasculoproliferative disorders bacillary angiomatosis (BA) and bacillary peliosis (BP) . The pathomechanisms of these tumorous proliferations are unknown . Our results suggest a novel bacterial two-step pathogenicity strategy, in which the pathogen triggers growth factor production for subsequent proliferation of its own host cells . In fact, B . henselae induces host cell production of the angiogenic factor vascular endothelial growth factor (VEGF), leading to proliferation of endothelial cells . The presence of B . henselae pili was associated with host cell VEGF production, as a Pil- mutant of B . henselae was unable to induce VEGF production . In turn, VEGF-stimulated endothelial cells promoted the growth of B . henselae . Immunohistochemistry for VEGF in specimens from patients with BA or BP revealed increased VEGF expression in vivo . These findings suggest a novel bacteria-dependent mechanism of tumour growth. ANZ J Surg, 2001 Oct, 71(10), 574 - 6 Prevalence of Helicobacter pylori in gastric cancer in a South-East Asian population by 14C-urea breath test; Chung AY et al.; BACKGROUND: Helicobacter pylori is believed to play an important role in the aetiology of gastric cancer . There is a great variability in seropositivity and histological frequency of H . pylori in gastric cancer . The present prospective study investigates the prevalence of H . pylori infection in gastric cancer patients using 14C-urea breath testing . METHODS: Patients with endoscopic biopsy-proven gastric cancer were fasted for 6 h prior to ingesting 18.5 x 104 Bq of 14C-urea cocktail orally . Breath samples were collected after 20 min by asking them to blow into a hyamine solution and measurements were read in a scintillation counter . RESULTS: Fifty out of 51 patients (98%) with gastric cancer were positive on the 14C-urea breath test compared to 29 patients (61%) who were positive on histology . There was no association between sex, age or tumour site, stage, differentiation, Lauren type and H . pylori status . The test was negative in one patient with cardial tumour in which histology of the resected specimen was also negative for the bacteria . CONCLUSIONS: Active H . pylori infection is highly prevalent in gastric cancer in a South-East Asian population . The 14C-urea breath test is a highly sensitive method for detecting the presence of H . pylori even in gastric adenocarcinoma irrespective of the stage. Khirurgiia (Mosk), 2001, (8), 17 - 20 {Ultrasound-controlled minimally invasive surgical interventions in abdominal abscesses}; Ektov VN et al.; Results of ultrasound-controlled minimally invasive surgical interventions (UAMISI) for abdominal abscesses are analyzed . 84 operations were performed in 72 patients with good results . Puncture method was used in 12 patients, drainage operation--in 58, endoscopy-guided puncture method--in 2 patients . Indications for different ultrasonic-assisted interventions are developed . It is concluded that at present the UAMISI are the alternative to conventional "open" treatment of abdominal abscesses. J Biol Chem, 2001 Nov 23, 276(47), 44044 - 51 Epub 2001 Sep 10. Conformational component in the coupled transfer of multiple electrons and protons in a monomeric tetraheme cytochrome; Louro RO et al.; Cell metabolism relies on energy transduction usually performed by complex membrane-spanning proteins that couple different chemical processes, e.g . electron and proton transfer in proton-pumps . There is great interest in determining at the molecular level the structural details that control these energy transduction events, particularly those involving multiple electrons and protons, because tight control is required to avoid the production of dangerous reactive intermediates . Tetraheme cytochrome c(3) is a small soluble and monomeric protein that performs a central step in the bioenergetic metabolism of sulfate reducing bacteria, termed "proton-thrusting," linking the oxidation of molecular hydrogen with the reduction of sulfate . The mechano-chemical coupling involved in the transfer of multiple electrons and protons in cytochrome c(3) from Desulfovibrio desulfuricans ATCC 27774 is described using results derived from the microscopic thermodynamic characterization of the redox and acid-base centers involved, crystallographic studies in the oxidized and reduced states of the cytochrome, and theoretical studies of the redox and acid-base transitions . This proton-assisted two-electron step involves very small, localized structural changes that are sufficient to generate the complex network of functional cooperativities leading to energy transduction, while using molecular mechanisms distinct from those established for other Desulfovibrio sp . cytochromes from the same structural family. J Biol Chem, 2001 Dec 14, 276(50), 47563 - 74 Epub 2001 Sep 10. Phosphatidylinositol 3-kinase-dependent pathways oppose Fas-induced apoptosis and limit chloride secretion in human intestinal epithelial cells . Implications for inflammatory diarrheal states; Abreu MT et al.; The epithelial lining of the intestine serves as a barrier to lumenal bacteria and can be compromised by pathologic Fas-mediated epithelial apoptosis . Phosphatidylinositol (PI)3-kinase signaling has been described to limit apoptosis in other systems . We hypothesized that PI3-kinase-dependent pathways regulate Fas-mediated apoptosis and barrier function in intestiynal epithelial cells (IEC) . IEC lines (HT-29 and T84) were exposed to agonist anti-Fas antibody in the presence or absence of chemical inhibitors of PI3-kinase (LY294002 and wortmannin) . Apoptosis, barrier function, changes in short circuit current (DeltaI(sc)), and expression of adhesion molecules were assessed . Inhibition of PI3-kinase strongly sensitized IEC to Fas-mediated apoptosis . Expression of constitutively active Akt, a principal downstream effector of the PI3-kinase pathway, protected against Fas-mediated apoptosis to an extent that was comparable with expression of a genetic caspase inhibitor, p35 . PI3-kinase inhibition sensitized to apoptosis by increasing and accelerating Fas-mediated caspase activation . Inhibition of PI3-kinase combined with cross-linking Fas was associated with increased permeability to molecules that were <400 Da but not those that were >3,000 Da . Inhibition of PI3-kinase resulted in chloride secretion that was augmented by cross-linking Fas . Confocal analyses revealed polymerization of actin and maintenance of epithelial cell adhesion molecule-mediated interactions in monolayers exposed to anti-Fas antibody in the context of PI3-kinase inhibition . PI3-kinase-dependent pathways, especially Akt, protect IEC against Fas-mediated apoptosis . Inhibition of PI3-kinase in the context of Fas signaling results in increased chloride secretion and barrier dysfunction . These findings suggest that agonists of PI3-kinase such as growth factors may have a dual effect on intestinal inflammation by protecting epithelial cells against immune-mediated apoptosis and limiting chloride secretory diarrhea. Biochemistry, 2001 Sep 18, 40(37), 11270 - 8 Mouse alpha1-syntrophin binding to Grb2: further evidence of a role for syntrophin in cell signaling; Oak SA et al.; Syntrophins have been proposed to serve as adapter proteins . Syntrophins are found in the dystrophin glycoprotein complex (DGC); defects in the constituents of this complex are linked to various muscular dystrophies . Blot overlay experiments demonstrate that alpha-dystroglycan, beta-dystroglycan, and syntrophins all bind Grb2, the growth factor receptor bound adapter protein . Mouse alpha1-syntrophin sequences were produced as chimeric fusion proteins in bacteria and found to also bind Grb2 in a Ca2+-independent manner . This binding was localized to the proline rich sequences adjacent to and overlapping with the N-terminal pleckstrin homology domain (PH1) . Grb2 bound syntrophin with an apparent KD of 563 +/- 15 nM . Grb2-C-SH3 domain bound syntrophin with slightly higher affinity than Grb2-N-SH3 domain . Crk-L, an SH2/SH3 protein of similar domain structure but different specificity, does not bind these syntrophin sequences. Biochemistry, 2001 Sep 18, 40(37), 11227 - 33 Ceramide inhibition of mammalian phospholipase D1 and D2 activities is antagonized by phosphatidylinositol 4,5-bisphosphate; Singh IN et al.; Ceramides inhibit phospholipase D (PLD) activity in several mammalian cell types . These effects have been related to preventing activation by ARF1, RhoA, and protein kinase C-alpha and -beta and therefore indicate that PLD1 is inhibited . In the present work, we investigated the effects of ceramides in inhibiting both PLD1 and PLD2 and the interaction with another activator, phosphatidylinositol 4,5-bisphosphate (PIP2) . PLD1 and PLD2 were overexpressed separately in Sf9 insect cells using baculovirus vectors . In our cell-free system, PLD1 activity was inhibited completely by C2-ceramide at sub-optimum concentrations of PIP2 (3 and 6 microM), whereas at supra-optimum PIP2 concentrations (18 and 24 microM) C2-ceramide did not inhibit PLD1 activity . Partially purified PLD2 exhibited an absolute requirement for PIP2 when the activity was measured using Triton X-100 micelles . Ceramides inhibited PLD2 activity, and this inhibition was decreased as PIP2 concentrations increased . However, C2-ceramide also reversibly inhibited the activity of PLD1 and PLD2 mutants in which binding of PIP2 was decreased, indicating that ceramides are interacting with the catalytic core of the mammalian PLDs . By contrast, C2-ceramide failed to produce a significant inhibition of PLDs from bacteria and plants . Our results provide a novel demonstration that ceramides reversibly inhibit mammalian PLD2 as well as PLD1 activities and that both of these actions are more pronounced when PIP2 concentrations are rate-limiting. Appl Microbiol Biotechnol, 2001 Aug, 56(3-4), 350 - 60 Flow cytometry in biotechnology; Rieseberg M et al.; Flow cytometry is a general method for rapidly analyzing large numbers of cells individually using light-scattering, fluorescence, and absorbence measurements . The power of this method lies both in the wide range of cellular parameters that can be determined and in the ability to obtain information on how these parameters are distributed in the cell population . Flow cytometric assays have been developed to determine both cellular characteristics such as size, membrane potential, and intracellular pH, and the levels of cellular components such as DNA, protein, surface receptors, and calcium . Measurements that reveal the distribution of these parameters in cell populations are important for biotechnology, because they better describe the population than the average values obtained from traditional techniques . This Mini-Review provides an overview of the principles of flow cytometry, with descriptions of methods used to measure various cellular parameters and examples of the application of flow cytometry in biotechnology . Finally, a discussion of the challenges and limitations of the method is presented along with a future outlook. Morfologiia, 2001, 119(2), 40 - 4 {Interaction of artificial carbon-mineral sorption preparations with the wound content}; Maiborodin IV et al.; The surface of SUMS1 was studied using scanning electron microscopy after contact with the wound contact . In vivo sorbent action was found to differ from in vitro adsorption properties of sorption drugs, as during the contact with organism tissue in the inflammation focus granule active surface is covered by fibrin, to which necrotic tissues, bacteria and immunocompetent cells adhere . The use of sorption drainage in acute and chronic inflammation lowers the challenge on lymphatic tissue because removal of sorption preparations also causes elimination of large fragments of non viable tissues, antigens and protein-cellular conglomerates that might block lymphatic vessels and regional lymph nodes. IUBMB Life, 2001 Mar, 51(3), 165 - 73 Oxygen signal transduction; Gilles-Gonzalez MA; Although manifestations of O2 adaptation have long been examined, only now are biochemical mechanisms of O2 regulation beginning to be understood . This article comments on the current state of knowledge about proteins that function as direct sensors of molecular oxygen and makes predictions about as yet undiscovered sensors. Mol Cell, 2001 Aug, 8(2), 251 - 62 DExD/H box RNA helicases: from generic motors to specific dissociation functions; Tanner NK et al.; RNA helicases of the DEAD box and related DExD/H proteins form a very large superfamily of proteins conserved from bacteria and viruses to humans . They have seven to eight conserved motifs, the characteristics of which are used to subgroup members into individual families . They are associated with all processes involving RNA molecules, including transcription, editing, splicing, ribosome biogenesis, RNA export, translation, RNA turnover, and organelle gene expression . Analysis of the three-dimensional structures obtained through the crystallization of viral and cellular RNA helicases reveals a strong structural homology to DNA helicases . In this review, we discuss our current understanding of RNA helicases and their biological function. J Mol Microbiol Biotechnol, 2001 Oct, 3(4), 611 - 7 A new class of glutaminase from Aspergillus oryzae; Thammarongtham C et al.; The koji mold Aspergillus oryzae is able to produce glutaminase which converts glutamine to glutamic acid, one of the most important flavor components in soy sauce . We present here the isolation and the complete nucleotide sequence of the glutaminase- encoding gene from A . oryzae U212, an industrial strain used in Thailand . N-terminal and internal amino acid sequences were determined from purified glutaminase . A 700-bp fragment was amplified by PCR using oligonucleotide primers designed from partial amino acid sequences . This PCR fragment was used as a homologous probe for screening an A . oryzae genomic DNA library . RT-PCR showed that the gene contained seven short introns . Sequence analysis revealed an open reading frame that encodes a protein of 690 amino-acid residues with a predicted molecular mass of 76 kDa . The N-terminal and internal amino acid sequences of the deduced protein exactly matched the ones determined from the purified protein . Comparison of the amino acid sequence with glutaminase sequences from other origins showed that A . oryzae glutaminase shares little homology with those of bacteria, eukaryote and mammals . The A . oryzae glutaminase gene was expressed in A . nidulans to confirm the presence of a functional glutaminase gene in the cloned DNA . To our knowledge, this is the first reported glutaminase gene cloned from filamentous fungi. Nature, 2001 Sep 6, 413(6851), 70 - 4 Mobilization of a Drosophila transposon in the Caenorhabditis elegans germ line; Bessereau JL et al.; Transposons have been enormously useful for genetic analysis in both Drosophila and bacteria . Mutagenic insertions constitute molecular tags that are used to rapidly clone the mutated gene . Such techniques would be especially advantageous in the nematode Caenorhabditis elegans, as the entire sequence of the genome has been determined . Several different types of endogenous transposons are present in C . elegans, and these can be mobilized in mutator strains (reviewed in ref . 1) . Unfortunately, use of these native transposons for regulated transposition in C . elegans is limited . First, all strains contain multiple copies of these transposons and thus new insertions do not provide unique tags . Second, mutator strains tend to activate the transposition of several classes of transposons, so that the type of transposon associated with a particular mutation is not known . Here we demonstrate that the Drosophila mariner element Mos1 can be mobilized in C . elegans . First, efficient mobilization of Mos1 is possible in somatic cells . Second, heritable insertions of the transposon can be generated in the germ line . Third, genes that have been mutated by insertion can be rapidly identified using inverse polymerase chain reaction . Fourth, these insertions can subsequently be remobilized to generate deletion and frameshift mutations by imperfect excision. J Immunol, 2001 Sep 15, 167(6), 3375 - 82 The effect of an anti-HLA-B27 immune response on CTL recognition of Chlamydia; Popov I et al.; The interplay between triggering bacteria and HLA-B27 in the pathogenesis of the spondyloarthropathies remains one of the most active areas of investigation in the rheumatic diseases . This has proved difficult to study systematically in the clinical setting, and in this study we utilized a rat model to address the influence that B27-related immunity may have on the process of generating anti-Chlamydia immunity . When splenocytes from HLA-B27 DNA-immunized Lewis (LEW) animals received restimulation in vitro with Chlamydia-treated cells from B27-transgenic LEW rats, we observed that in addition to the expected CTL recognition of HLA-B27, there was also anti-Chlamydia CTL killing of Chlamydia-sensitized syngeneic fibroblast targets . This was not seen when responding cells in vitro were naive LEW splenocytes . To confirm the existence of CTLs recognizing both HLA-B27 and Chlamydia, LEW rats were immunized with B27-transgenic LEW cells, instead of the B27 DNA construct . Splenocytes from the immune rats were restimulated in vitro with Chlamydia-treated B27-transgenic LEW cells . In this instance, the CTLs retained the allele-specific recognition of HLA-B27, as well as recognition of Chlamydia-sensitized syngeneic fibroblasts . Thus, if there is prior expansion of an immune response against HLA-B27, then the resulting splenocytes demonstrate a reduced threshold for generating a primary anti-Chlamydia CTL response . These studies implicate a dynamic interrelationship between recognition of HLA-B27 and Chlamydia trachomatis . The results may have implications for deciphering the cellular basis of Chlamydia-induced reactive arthritis. J Bacteriol, 2001 Oct, 183(19), 5544 - 53 Genetics and regulation of chitobiose utilization in Borrelia burgdorferi; Tilly K et al.; Borrelia burgdorferi spends a significant proportion of its life cycle within an ixodid tick, which has a cuticle containing chitin, a polymer of N-acetylglucosamine (GlcNAc) . The B . burgdorferi celA, celB, and celC genes encode products homologous to transporters for cellobiose and chitobiose (the dimer subunit of chitin) in other bacteria, which could be useful for bacterial nutrient acquisition during growth within ticks . We found that chitobiose efficiently substituted for GlcNAc during bacterial growth in culture medium . We inactivated the celB gene, which encodes the putative membrane-spanning component of the transporter, and compared growth of the mutant in various media to that of its isogenic parent . The mutant was no longer able to utilize chitobiose, while neither the mutant nor the wild type can utilize cellobiose . We propose renaming the three genes chbA, chbB, and chbC, since they probably encode a chitobiose transporter . We also found that the chbC gene was regulated in response to growth temperature and during growth in medium lacking GlcNAc. J Bacteriol, 2001 Oct, 183(19), 5491 - 5 Properties of a thermostable nitrate reductase from the hyperthermophilic archaeon Pyrobaculum aerophilum; Afshar S et al.; The nitrate reductase of the hyperthermophilic archaeon Pyrobaculum aerophilum was purified 137-fold from the cytoplasmic membrane . Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, the enzyme complex consists of three subunits with apparent molecular weights of 130,000, 52,000, and 32,000 . The enzyme contained molybdenum (0.8-mol/mol complex), iron (15.4-mol/mol complex) and cytochrome b (0.49-mol/mol complex) as cofactors . The P . aerophilum nitrate reductase distinguishes itself from nitrate reductases of mesophilic bacteria and archaea by its very high specific activity using reduced benzyl viologen as the electron donor (V(max) with nitrate, 1,162 s(-1) (326 U/mg); V(max) with chlorate, 1,348 s(-1) (378 U/mg) {assayed at 75 degrees C}) . The K(m) values for nitrate and chlorate were 58 and 140 microM, respectively . Azide was a competitive inhibitor and cyanide was a noncompetitive inhibitor of the nitrate reductase activity . The temperature optimum for activity was > 95 degrees C . When incubated at 100 degrees C, the purified nitrate reductase had a half-life of 1.5 h . This study constitutes the first description of a nitrate reductase from a hyperthermophilic archaeon. Genomics, 2001 Sep, 77(1-2), 65 - 70 The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders; Kenmochi N et al.; Mitochondria possess their own translational machinery, which is composed of components distinct from their cytoplasmic counterparts . To investigate the possible involvement of mitochondrial ribosomal defects in human disease, we mapped nuclear genes that encode mitochondrial ribosomal proteins (MRPs) . We generated sequence-tagged sites (STSs) of individual MRP genes that were able to be detected by PCR . They were placed on an STS content map of the human genome by typing of radiation hybrid panels . We located 54 MRP genes on the STS-content map and assigned these genes to cytogenetic bands of the human chromosomes . Although mitochondria are thought to have originated from bacteria, in which the genes encoding ribosomal proteins are clustered into operons, the mapped MRP genes are widely dispersed throughout the genome, suggesting that transfer of each MRP gene to the nuclear genome occurred individually . We compared the assigned positions with candidate regions for mendelian disorders and found certain genes that might be involved in particular diseases . This map provides a basis for studying possible roles of MRP defects in mitochondrial disorders. Geochim Cosmochim Acta, 2000 Dec, 64(23), 4049 - 81 Elongated prismatic magnetite crystals in ALH84001 carbonate globules: potential Martian magnetofossils; Thomas-Keprta KL et al.; Using transmission electron microscopy (TEM), we have analyzed magnetite (Fe3O4) crystals acid-extracted from carbonate globules in Martian meteorite ALH84001 . We studied 594 magnetites from ALH84001 and grouped them into three populations on the basis of morphology: 389 were irregularly shaped, 164 were elongated prisms, and 41 were whisker-like . As a possible terrestrial analog for the ALH84001 elongated prisms, we compared these magnetites with those produced by the terrestrial magnetotactic bacteria strain MV-1 . By TEM again, we examined 206 magnetites recovered from strain MV-1 cells . Natural (Darwinian) selection in terrestrial magnetotactic bacteria appears to have resulted in the formation of intracellular magnetite crystals having the physical and chemical properties that optimize their magnetic moment . In this study, we describe six properties of magnetite produced by biologically controlled mechanisms (e.g., magnetotactic bacteria), properties that, collectively, are not observed in any known population of inorganic magnetites . These criteria can be used to distinguish one of the modes of origin for magnetites from samples with complex or unknown histories . Of the ALH84001 magnetites that we have examined, the elongated prismatic magnetite particles (similar to 27% of the total) are indistinguishable from the MV-1 magnetites in five of these six characteristics observed for biogenically controlled mineralization of magnetite crystals. J Geophys Res, 2000 May 25, 105(E5), 11981 - 90 Greenhouse warming by CH4 in the atmosphere of early Earth; Pavlov AA et al.; Earth appears to have been warm during its early history despite the faintness of the young Sun . Greenhouse warming by gaseous CO2 and H2O by itself is in conflict with constraints on atmospheric CO2 levels derived from paleosols for early Earth . Here we explore whether greenhouse warming by methane could have been important . We find that a CH4 mixing ratio of 10(-4) (100 ppmv) or more in Earth's early atmosphere would provide agreement with the paleosol data from 2.8 Ga . Such a CH4 concentration could have been readily maintained by methanogenic bacteria, which are thought to have been an important component of the biota at that time . Elimination of the methane component of the greenhouse by oxidation of the atmosphere at about 2.3-2.4 Ga could have triggered the Earth's first widespread glaciation. Polar Biol, 1999 May, 21(5), 285 - 94 Ciliated protozoa of two antarctic lakes: analysis by quantitative protargol staining and examination of artificial substrates; Kepner RL Jr et al.; Planktonic and artificial substrate-associated ciliates have been identified in two perennially ice-covered antarctic lakes of the McMurdo Dry Valleys . Abundances estimated by quantitative protargol staining ranged from < 5 to 31690 cells l-1, levels that are comparable to those previously obtained using other methods . Nineteen ciliate taxa were identified from these lakes, with the most frequently encountered genera being Plagiocampa, Askenasia, Monodinium, Sphaerophrya and Vorticella . The taxonomic findings compare favorably with those of previous investigators; however four previously unreported genera were observed in both Lakes Fryxell and Hoare . The variability in the depth distributions of ciliates in Lake Fryxell is explained in terms of lake physicochemical properties and ciliate prey distributions, while factors related to temporal succession in the Lake Hoare assemblage remain unexplained . Local marine or temperate zone freshwater habitats are a more likely source than the surrounding dry valleys soils for present ciliate colonists in these lakes . Although the taxonomic uncertainties require further examination, our results suggest that ciliate populations in these antarctic lakes undergo significant fluctuations and are more diverse than was previously recognized. Gravit Space Biol Bull, 2000 Jun, 13(2), 13 - 23 Metazoans in extreme environments: adaptations of hydrothermal vent and hydrocarbon seep fauna; McMullin ER et al.; Some of the most extreme environments where animals survive are associated with active vents and seeps in the deep sea . In addition to the extreme pressure, low temperatures, and lack of light that characterize the deep sea in general, a variety of other factors that are hostile to most animals prevail in these environments . Hydrothermal vent regions show extremes in temperature, areas of very low oxygen, and the presence of toxic hydrogen sulfide and heavy metals . Hydrocarbon seeps, though much cooler than vents, also have regions of very low oxygen and high hydrogen sulfide, as well as other potentially harmful substances such as crude oil and supersaturated brine . Specially adapted animals not only tolerate these conditions, they often thrive under them . In most cases this tolerance is due to a combination of physiological and behavioral adaptations that allow animals to avoid the extremes of their habitats and yet benefit from the chemoautotrophic production characteristic of these environments. Eur J Protistol, 1999 Oct 15, 35(3), 327 - 37 Devescovinid trichomonad with axostyle-based rotary motor ("Rubberneckia"): taxonomic assignment as Caduceia versatilis sp . nov; d'Ambrosio U et al.; An amitochondriate trichomonad cell of the family Devescovinidae (Class Parabasalia), helped demonstrate the fluid model of lipoprotein cell membranes . This wood-ingesting symbiont in the hindgut of the dry wood-eating termite Cryptotermes cavifrons is informally known to cell biologists as "Rubberneckia" . As the microtubular axo-style complex generates force causing clockwise movement of the entire anterior portion of the cell at the shear zone the protist displays "head" rotation . Studies by phase contrast and videomicroscopy of live cells, of whole mounts by scanning, and thin sections by transmission electron microscopy extend the observations of Tamm and Tamm {24-26} and Tamm {19-23} . Habitat, cell shape, size, nuclear features, parabasal apparatus and other morphological details permit the assignment of "Rubberneckia" to Kirby's cosmopolitan genus Caduceia . This large-sized devescovinid has distinctive parabasal gyres, an axostylar rotary, motor, and regularly-associated nonflagellated, fusiform and flagellated rod epibiotic surface bacteria . In addition to regularly aligned epibionts intranuclear and endocytoplasmic bacteria are abundant and hydrogenosomes are Present . "Rubberneckia" is compared here to the other seven species of Caduceia . Since it is clearly sufficiently distinctive to warrant new species status, we named it C . versatilis. Proc NIPR Symp Antarct Meteorites, 1995 Oct, 8, 258 - 67 Geochemical characteristics of organic compounds in a permafrost sediment core sample from northeast Siberia, Russia; Matsumoto GI et al.; We studied total organic carbon (TOC), hydrocarbons and fatty acids in a permafrost sediment core sample (well 6-90, length 32.0 m, 1.5-2.5 Ma BP) from northeast Siberia (approximately 70 degrees N, 158 degrees E), Russia, to elucidate their geochemical features in relation to source organisms and paleoenvironmental conditions . Long-chain n-alkanes and n-alkanoic acids (>C19) were most predominant hydrocarbons and fatty acids, respectively, so organic matter in the sediment core was derived mainly from vascular plants and, to a much smaller extent, from bacteria . Low concentrations of unsaturated fatty acids revealed that organic matter in the sediment core was considerably degraded during and/or after sedimentation . The predominance of vascular plant components, the major ionic components of nonmarine sources, and geological data strongly implied that the sediment layers were formed in shallow lacustrine environments, such as swamp with large influences of tundra or forest-tundra vegetation . Also, no drastic changes in paleoenvironmental conditions for biological activity or geological events, such as sea transgressions or ice-sheet influences, occurred at the sampling site approximately 100 km from the coast of the East Siberian Sea during the late Pliocene an early Pleistocene periods. Appl Spectrosc, 1999 Sep, 53(9), 338A - 355A Ion mobility spectrometry: arriving on site and moving beyond a low profile; Baumbach JI et al.; NASA: Trends in the development of ion mobility spectrometry are reviewed . A discussion of general principles of operation includes an overview and examines drift tube technology and ionization and response . A discussion of the scope of applications examines detection and characterization of single substances and complex mixtures . The technology that permitted the development of hand-held instruments is reviewed . A discussion of barriers to hand-held ion mobility spectrometers includes gas-phase chemistry, ion characterization and separation, sample inlets, bacterial assays by ion mobility spectrometry, databases and artificial intelligence, and ion sources . Directions for future applications and research are examined . Adv Space Res, 1983, 3(8), 39 - 42 An extraterrestrial habitat on Earth: the algal mat of Don Juan {correction of Jaun} Pond; Siegel BZ et al.; On the edge of Don Juan Pond in the Wright Valley of Antarctica lies a mat of mineral and detritus cemented by organic matter . In spite of a CaCl2 concentration of about 33% (w/v), the mat contains Oscillatoria and other cyanobacteria, unicellular forms, colonial forms rich in carotenoids, and diatoms . Bacteria are rare; fungal filaments are not . Oscillatoria showed motility but only at temperatures <10 degrees C . Acetone extracts of the mat and nearby muds yielded visible spectra similar to those of laboratory grown O . sancta, with 50- to 70-fold molar ratio of chlorophyll a to b . Although rare, tardigrades were also found . The algal mat had enzymatic activities characteristic of peroxidase, catalase, dehydrogenase, and amylase . Cellulose, chitin, protein, lipid and ATP were present . Previously, algae in the Wright Valley have been described in melt water, not in the brine itself . Wright Valley has been used as a near sterile Martian model . It obviously contains an array of hardy terrestrial organisms. Adv Space Res, 1983, 3(9), 153 - 8 Experimental and theoretical analysis of the influence of gravity at the cellular level: a review; Tairbekov MG et al.; The present paper is a review of the experimental investigations published in the literature and performed by the authors on space vehicles . The paper also gives an analysis of theoretical concepts concerning gravitational effects on the cell . Taking this into account, the authors put forth a hypothesis that free-living unicellular organisms are indifferent to variations in the magnitude and direction of the gravitational field. J Gravit Physiol, 1998 Jul, 5(1), P125 - 6 Microgravity and hypergravity effect on survival and reproduction of microinvertebrates; Ricci C et al.; Preliminary to carry out long-term experiments on the International Space Station (ISS) using living orgainisms, the capacity of the experimental organisms to cope with perturbations of gravity should be tested . Actually, animals have evolved under gravity, because on earth gravity force cannot be eluded, and several features that influence life-history traits may be affected by the presence of gravity . Among the other features, feeding efficiency may be affected by gravity if the animals feed by filtering suspended particles, creating currents that carry the particulate food to their mouth opening . In presence of gravity the food particles tend to sink to the bottom and filter-feeders must be able to suspend and collect the particles with some apparatus such as ciliary wreaths . It can be predicted that hypergravity, increasing the particle sedimentation rate, will reduce the animal filtering efficiency, while microgravity will increase filtering rate . Differently, some bacteriophagous animals do not possess structures to collect their food, but commonly live and move into sediment and feed on the bacteria upon encounter . Hypergravity will apply higher pressure on their bodies, and could force them to adhere to some surface and to reduce their displacement, and microgravity could impede adhesion to the surface and make food item encounters improbable . Thus, gravity perturbations may affect animal life-history traits, such as survival or fecundity, by influencing their feeding efficiency . In this study we exposed a filter-feeding organism (Macrotrachela quadricornifera, Rotifera Bdelloidea) and a bacteriophagous one (Panagrolaimus rigidus, Nematoda) to both microgravity and hypergravity to test their reproduction capacity under such stressful conditions, and their suitability as models for experiments on the ISS. Natl Widl, 1996 Aug-Sep, 34(5), 36 - 42 The cave that holds clues to life on Mars; Nelson P; Deep in Lechuguilla Cave, a researcher ponders slots carved millions of years ago by dripping sulfuric acid . Though the cave was formed by acid bubbling up from below, here gases condensed on the chamber's ceiling and then rained down as acid . Scientists think Mars may also hold caves carved by sulfuric acid . On Earth, almost all other caves are formed by flowing water. J Phys Chem B Condens Matter Mater Surf Interfaces Biophys, 1997, 101(37), 7211 - 20 Exciton dynamics in FMO bacteriochlorophyll protein at low temperatures; Freiberg A et al.; A time response over almost 5 decades (from 10(-13) to about 10(-8) s) to a (sub)picosecond laser pulse excitation has been observed in the Fenna, Matthews, and Olson (FMO) antenna protein trimer . The FMO protein is unique in having a fine-structured bacteriochiorophyll a Qy exciton absorption spectrum over the whole investigated temperature range between 6 and 160 K . As measured by a two-color pump-probe differential absorption, the population decay of the exciton states of seven strongly coupled bacteriochlorophyll a molecules in a protein monomer is the dominant dynamical process in the subpicosecond time domain . The through-band scattering takes a few picoseconds and depends only weakly on temperature, probably because of a low density of exciton states . At low temperatures, evidence for a slow pico-nanosecond relaxation process has also been obtained via time-dependent red-shift and broadening of the exciton emission spectrum . Two nonexclusive tentative interpretations to this effect have been provided . The phenomenon may be due to exciton solvation in the surrounding protein and water-glycerol matrix or/and due to slow scattering of closely spaced bacteriochlorophyll a exciton states in a protein trimer . The shape of the excited-state absorption spectrum (arising from transitions between singly and doubly excited exciton states) and its oscillator strength has been roughly estimated from the analysis of the pump-probe spectrum . The spectrum peaks at around 805 nm and is less featured compared to the ground-state absorption spectrum . Both spectra have comparable strength. Int J Syst Bacteriol, 1988 Jul, 38(3), 291 - 302 Morphology as a basis for taxonomy of large spirochetes symbiotic in wood-eating cockroaches and termites: Pillotina gen . nov., nom . rev.; Pillotina calotermitidis sp . nov., nom . rev.; Diplocalyx gen . nov., nom . rev.; Diplocalyx calotermitidis sp . nov., nom . rev.; Hollandina gen . nov., nom.{TRUNCATED}; Bermudes D et al.; The purposes of this paper are (i) to present a framework for the morphometric analysis of large uncultivable spirochetes that are symbiotic in wood-eating cockroaches and termites; (ii) to revive, in accordance with the rules of the International Code of Nomenclature of Bacteria, the names of three genera (Pillotina, Diplocalyx, and Hollandina) and three species (Pillotina calotermitidis, Diplocalyx calotermitidis, and Hollandina pterotermitidis) for the same organisms to which the names were originally applied, because these names were not included on the 1980 Approved Lists of Bacterial Names; and (iii) to formally propose the name Clevelandina reticulitermitidis for a new genus and species of spirochetes from the termite Reticulitermes tibialis . None of these genera and species has been cultivated either axenically or in mixed culture; hence, all are based on type-descriptive material. Nature, 1988 Aug 4, 334, 424 - 7 Exceptional preservation of fossils in an Upper Proterozoic shale; Butterfield NJ et al.; Late Proterozoic organisms must have been diverse and widely distributed, but in general their fossil record is both taxonomically and environmentally limited . Exceptional preservation of Proterozoic fossils is not unknown, but it is usually associated with silicified carbonates from restricted peritidal or playa lake environments . We report here an exceptionally well preserved and distinctive assemblage of Late Proterozoic fossils from subtidal marine shales . In addition to the sphaeromorphic acritarchs and cyanobacterial sheaths routinely preserved in Proterozoic rocks, this assemblage includes multicellular algae ('seaweeds'), a diverse assortment of morphologically complex protistan vesicles, and probable heterotrophic bacteria . Thus, it provides one of the clearest and most taxonomically varied views of Proterozoic life yet reported. Nature, 1984 May 24, 309, 340 - 2 Suboxic diagenesis in banded iron formations; Walker JC; Anomalous isotopic composition has been reported for the carbon in carbonate minerals of banded iron formations . Well studied examples show and enrichment in the light isotope of carbon, 12C . This enrichment presumably reflects unusual circumstances in the deposition of these sedimentary rocks . It is suggested here that the isotopically-light carbonate results from early diagenetic oxidation by bacteria of substantial amounts of isotopically light organic carbon . The electron acceptor that permits oxidation in the absence of free oxygen is presumed to the iron(III) which may have been significantly more abundant in the initial chemical precipitate than in the post-diagenetic sedimentary rock. Chem Geol, 1984, 42, 25 - 43 Extended hopanoids in peat environments; Quirk MM et al.; Detailed results are presented for the distributions of triterpenoid alkanes, acids and alcohols of the hopane family in ten samples of peat from three environments, and of contributing organisms in the case of Lyne of Skene, Scotland . Extended hopanoids of the beta alpha and alpha beta configuration appear at the very earliest stage of diagenesis . Such environments appear to be characterised by particular distributions of C32 hopanoid acids and alcohols, and a high preponderance of the C31 alpha beta hopane. Biol Sci Space, 1998 Jun, 12(2), 115 - 8 A materially-closed aquatic-ecosystem: a useful tool for determining changes of ecological processes in space; Sugiura K; A materially-closed aquatic ecosystem (microcosm) was developed . The microcosm contained two families of green algae and blue-green alga as primary producers, protozoa, two species of rotifers and oligochaetes as consumers, and bacteria as decomposers . The microcosm could be readily replicated . It was confirmed the population densities of each organism were almost constant for 365 days without artificial operation except temperature and light . The population dynamics and the spatial patterns of the organisms were simulated by mathematical models . This hermetically-sealed microcosm could be a useful subject to investigate ecology under space environment. Biol Sci Space, 1998 Jun, 12(2), 112 - 4 Ecological cultivation ark (ECA) project--mutation and evolution of micro-organisms in space; Hashimoto H et al.; Ecological cultivation capsules (ECC), that is a materially sealed microcosm . composed of primary producers, consumers and bacteria as a decomposer were developed in order to cultivate bacteria without any artificial operation for long duration more than 10 years in space . It is planned to be left on the space station to study the process that bacteria in MIR space station had acquired their resistance to cosmic ray radiation as well as ultra-violet light . As contrasted with the space experiment, bacteria are cultivating in the ECC on the ground to trace the changes of bacteria under the simulated radiation dose in Earth orbit. Symbiosis, 1997, 22, 229 - 39 Staurojoenina and other symbionts in Neotermes from San Salvador Island, Bahamas; Dolan M et al.; Staurojoenina, a conspicuous hypermastigote protist (undocumented in any Neotermes) and other hindgut symbionts are reported for the first time in Neotermes nr . jouteli, a dry-wood-eating termite (Kalotermitidae), from the red mangroves at the northeast corner of San Salvador Island . Other distinctive protists (Macrotrichomonas, Metadevescovina, two morphotypes of small trichomonads) and bacteria (Arthromitus-type filamentous spore-formers) symbionts were also found in this termite . This Staurojoenina sp . replete with epibiotic bacterial symbionts is not distinguished from previously described species of Staurojoenina. Chem Geol, 1997, 134, 277 - 88 Productivity-induced sulphur enrichment of hydrocarbon-rich sediments from the Kimmeridge Clay Formation; Lallier-Verges E et al.; This work aims to highlight the relationship between primary productivity, sulphate reduction and organic carbon preservation in cyclic marine sediments from the Kimmeridge Clay Formation . A concomitant increase of the total sulphur content with the preserved organic content (TOC), shows the progressive supply of both metabolisable organic matter and resistant organic matter is linked to primary productivity . However, variations in sulphate reduction efficiency, based on elemental abundance and isotopic composition of sulphur, reveal that the proportion of metabolisable vs . resistant organic matter has varied along the cycles . This is interpreted in terms of the variation in organic delivery . Organic sulphur content is found to be proportional to the organic matter content, whereas concentrations of pyritic sulphur are constant at very high (> 10% TOC) values . This result is explained by a limitation of available iron for pyritisation at times of very high organic flux . Under such conditions, HS- in excess could be responsible for the early formation of organo-sulphur compounds and thus for the preservation of highly aliphatic (i.e . lipid-rich) organic matter. J Geol Soc London, 1997 May, 154(3), 377 - 402 The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front; Russell MJ et al.; Here we argue that life emerged on Earth from a redox and pH front at c . 4.2 Ga . This front occurred where hot (c . 150 degrees C), extremely reduced, alkaline, bisulphide-bearing, submarine seepage waters interfaced with the acid, warm (c . 90 degrees C), iron-hearing Hadean ocean . The low pH of the ocean was imparted by the ten bars of CO2 considered to dominate the Hadean atmosphere/hydrosphere . Disequilibrium between the two solutions was maintained by the spontaneous precipitation of a colloidal FeS membrane . Iron monosulphide bubbles comprising this membrane were inflated by the hydrothermal solution upon sulphide mounds at the seepage sites . Our hypothesis is that the FeS membrane, laced with nickel, acted as a semipermeable catalytic boundary between the two fluids, encouraging synthesis of organic anions by hydrogenation and carboxylation of hydrothermal organic primers . The ocean provided carbonate, phosphate, iron, nickel and protons; the hydrothermal solution was the source of ammonia, acetate, HS-, H2 and tungsten, as well as minor concentrations of organic sulphides and perhaps cyanide and acetaldehyde . The mean redox potential (delta Eh) across the membrane, with the energy to drive synthesis, would have approximated to 300 millivolts . The generation of organic anions would have led to an increase in osmotic pressure within the FeS bubbles . Thus osmotic pressure could take over from hydraulic pressure as the driving force for distension, budding and reproduction of the bubbles . Condensation of the organic molecules to polymers, particularly organic sulphides, was driven by pyrophosphate hydrolysis . Regeneration of pyrophosphate from the monophosphate in the membrane was facilitated by protons contributed from the Hadean ocean . This was the first use by a metabolizing system of protonmotive force (driven by natural delta pH) which also would have amounted to c . 300 millivolts . Protonmotive force is the universal energy transduction mechanism of life . Taken together with the redox potential across the membrane, the total electrochemical and chemical energy available for protometabolism amounted to a continuous supply at more than half a volt . The role of the iron sulphide membrane in keeping the two solutions separated was appropriated by the newly synthesized organic sulphide polymers . This organic take-over of the membrane material led to the miniaturization of the metabolizing system . Information systems to govern replication could have developed penecontemporaneously in this same milieu . But iron, sulphur and phosphate, inorganic components of earliest life, continued to be involved in metabolism. Nature, 1996 Jul 11, 382, 111 - 2 Breathing room for early animals Knoll AH. Did an increase in atomospheric oxygen concentration some time during the Neoproterozoic era 1,000 to 543 million years ago, make possible the diversification of multicelluar animals? Acta Astronaut, 1995 Oct-Dec, 36(8-12), 615 - 23 Animal protein production modules in biological life support systems: novel combined aquaculture techniques based on the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.); Blum V et al.; Based on the experiences made with the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) which was primarily developed for long-term and multi-generation experiments with aquatic animals and plants in a space station highly effective fresh water recycling modules were elaborated utilizing a combination of ammonia oxidizing bacteria filters and higher plants . These exhibit a high effectivity to eliminate phosphate and anorganic nitrogen compounds and are, in addition, able to contribute to the oxygen supply of the aquatic animals . The C.E.B.A.S . filter system is able to keep a closed artificial aquatic ecosystem containing teleost fishes and water snails biologically stable for several month and to eliminate waste products deriving from degraded dead fishes without a decrease of the oxygen concentration down to less than 3.5 mg/l at 25 degrees C . More advanced C.E.B.A.S . filter systems, the BIOCURE filters, were also developed for utilization in semiintensive and intensive aquaculture systems for fishes . In fact such combined animal-plant aquaculture systems represent highly effective productions sites for human food if proper plant and fish species are selected . The present papers elucidates ways to novel aquaculture systems in which herbivorous fishes are raised by feeding them with plant biomass produced in the BIOCURE filters and presents the scheme of a modification which utilizes a plant species suitable also for human nutrition . Special attention is paid to the benefits of closed aquaculture system modules which may be integrated into bioregenerative life support systems of a higher complexity for, e.g., lunar or planetary bases including some psychological aspects of the introduction of animal protein production into plant-based life support systems . Moreover, the basic reproductive biological problems of aquatic animal breeding under reduced gravity are explained leading to a disposition of essential research programs in this context. Nature, 1987 Sep 3, 329, 48 - 51 Isotopic compositions and probable origins of organic molecules in the Eocene Messel shale; Hayes JM et al.; The sediments that now comprise the Messel shale accumulated 47 +/- 2 million years ago in anaerobic waters at the bottom of a lake . Subsequent depths of burial have not exceeded 300 m, nor has the temperature of the shale exceeded 40 degrees C . Contents of organic carbon reach 25%, and preservation of molecular structures has been excellent . Sixteen different geoporphyrins, including three derived from bacteriochlorophylls of the d series and thus indicative of the existence in the lake of an anaerobic photic zone, have been isolated and identified . Here, we show that the carbon isotopic compositions of these and other biomarkers allow identification of specific sources for some materials and reconstruction of carbon flows within the lake and its sediments . The 13C content of organic matter synthesized by lacustrine primary producers can be estimated from the observed 13C content of the geoporphyrins derived from their chlorophylls . Total organic material in the shale is depleted in 13C by six parts per thousand relative to that input . This difference cannot be explained by selective loss of components enriched in 13C, nor, as shown by isotopic compositions of other biomarkers, by inputs from land plants surrounding the lake or from methanogenic bacteria. Acta Astronaut, 1996 Oct, 39(8), 617 - 22 Perspectives of different type biological life support systems (BLSS) usage in space missions; Bartsev SI et al.; In the paper an attempt is made to combine three important criteria of LSS comparison: minimum mass, maximum safety and maximum quality of life . Well-known types of BLSS were considered: with higher plant, higher plants and mushrooms, microalgae, and hydrogen-oxidizing bacteria . These BLSSs were compared in terms of "integrated" mass for the case of a vegetarian diet and a "normal" one (with animal proteins and fats) . It was shown that the BLSS with higher plants and incineration of wastes becomes the best when the exploitation period is more than 1 yr . The dependence of higher plants' LSS structure on operation time was found . Comparison of BLSSs in terms of integral reliability (this criterion includes mass and quality of life criteria) for a lunar base scenario showed that BLSSs with higher plants are advantageous in reliability and comfort . This comparison was made for achieved level of technology of closing and for perspective one. Gravit Space Biol Bull, 1998 May, 11(2), 23 - 30 Earth's early biosphere; Des Marais DJ; Understanding our own early biosphere is essential to our search for life elsewhere, because life arose on Earth very early and rocky planets shared similar early histories . The biosphere arose before 3.8 Ga ago, was exclusively unicellular and was dominated by hyperthermophiles that utilized chemical sources of energy and employed a range of metabolic pathways for CO2 assimilation . Photosynthesis also arose very early . Oxygenic photosynthesis arose later but still prior to 2.7 Ga . The transition toward the modern global environment was paced by a decline in volcanic and hydrothermal activity . These developments allowed atmospheric O2 levels to increase . The O2 increase created new niches for aerobic life, most notably the more advanced Eukarya that eventually spawned the megascopic fauna and flora of our modern biosphere. Limnol Oceanogr, 1996 Dec, 41(8), 1629 - 50 Pathways of carbon oxidation in continental margin sediments off central Chile; Thamdrup B et al.; Rates and oxidative pathways of organic carbon mineralization were determined in sediments at six stations on the shelf and slope off Concepcion Bay at 36.5 degrees S . The depth distribution of C oxidation rates was determined to 10 cm from accumulation of dissolved inorganic C in 1-5-d incubations . Pathways of C oxidation were inferred from the depth distributions of the potential oxidants (O2, NO3-, and oxides of Mn and Fe) and from directly determined rates of SO4(2-) reduction . The study area is characterized by intense seasonal upwelling, and during sampling in late summer the bottom water over the shelf was rich in NO3- and depleted of O2 . Sediments at the four shelf stations were covered by mats of filamentous bacteria of the genera Thioploca and Beggiatoa . Carbon oxidation rates at these sites were extremely high near the sediment surface (>3 micromol cm-3 d-1) and decreased exponentially with depth . The process was entirely coupled to SO4(2-) reduction . At the two slope stations where bottom-water O2 was > 100 microM, C oxidation rates were 10-fold lower and varied less with depth; C oxidation coupled to the reduction of O2, NO3-, and Mn oxides combined to yield an estimated 15% of the total C oxidation between 0 and 10 cm . Carbon oxidation through Fe reduction contributed a further 12-29% of the depth-integrated rate, while the remainder of C oxidation was through SO4(2-) reduction . The depth distribution of Fe reduction agreed well with the distribution of poorly crystalline Fe oxides, and as this pool decreased with depth, the importance of SO4(2-) reduction increased . The results point to a general importance of Fe reduction in C oxidation in continental margin sediments . At the shelf stations, Fe reduction was mainly coupled to oxidation of reduced S . These sediments were generally H2S-free despite high SO4(2-) reduction rates, and precipitation of Fe sulfides dominated H2S scavenging during the incubations . A large NO3- pool was associated with the Thioploca, and the shelf sediments were thus enriched in NO3- relative to the bottom water, with maximum concentrations of 3 micromol cm-3 . The NO3- was consumed during our sediment incubations, but no effects on either C or S cycles could be discerned. Biol Sci Space, 1996 Dec, 10(4), 262 - 70 {Meteoritics and mineralogy on possible ancient Martian life}; Tsuchiyama A; Possible relic biogenic activity in martian meteorite ALH84001 was proposed by McKay et al . (Science, 273, 924-930, 1996) . This ancient meteorite of 4.5 billion years old contains abundant carbonates as secondary minerals precipitated from a fluid on the martian surface . They showed the following lines of evidence for the ancient life; (1) unique mineral compositions and biominerals, (2) polycyclic aromatic hydrocarbons (PAHs) in association with the carbonates, and (3) unique structures and morphologies typical of nanobacteria or microfossils . This review is divided into two parts; one is on the martian meteorites in general and ALH84001, which has many features unlike other martian meteorites, and the other is on mineralogical (biomineralogical) and geochemical features of the carbonates and microfossil-like structures . There is little doubt that ALH84001 is from Mars as well as eleven other SNC meteorites . However, the mineralogical and biomineralogical evidence for martian bacteria given by McKay et al . (1996) is controversial, and could be formed by non-biogenic processes . Thus, further study of ALH84001 and other martian meteorites is required . We also need to consider the future Mars mission especially sample return mission. Adv Space Res, 1994 Nov, 14(11), 89 - 98 C.E.B.A.S . MINI MODULE: test results of an artificial (man-made) aquatic ecosystem; Blum V et al.; The original Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is a long-term multi-generation research facility for experiments with aquatic animals and plants in a space station the development of which is surrounded by a large international scientific program . In addition, a miniaturized laboratory prototype, the C.E.B.A.S . MINI MODULE, with a total volume of about 10-12 liters for a Spacelab middeck locker was developed and a first version was tested successfully for two weeks with a population of fishes (Xiphophorus helleri) in the animal tank and a Ceratophyllum spec . in the illuminated higher plant growth chamber . The water recycling system consisted of a bacteria filter and a mechanical filter and the silastic tubing gas exchanger was separated by valves for the utilization in emergency cases only . Data were collected with the acquisition module of the original C.E.B.A.S . process control system . In addition, an optimized version was tested for 7 weeks with fishes and plants and thereafter with fish and with plants only for 2 and 1 weeks, resp. . The paper presents the relevant water parameters (e.g., pH, pressure, temperature, oxygen saturation, flow rate, ion concentrations) during the test period as well as morphological and physiological data of the enclosed animals and plants . On the basis of the given results the possible role of the C.E.B.A.S . system as a scientific tool in artificial ecosystem research and for the development of a combined animal-plant intensive aquaculture system and its utilization in bioregenerative life support is discussed. Adv Space Res, 1994 Nov, 14(11), 53 - 60 Plant-module for autonomous space support (P-MASS); Luttges MW et al.; A wide variety of technical and science questions arise when attempting to envision the long-term support of plants, algae and bacteria in space . Currently, spaceflight data remain elusive since there are no U.S . carriers for investigating either the germane technical or scientific issues . The first flight of the Commercial Experiment Transporter (COMET) will provide a nominal 30 day orbital opportunity to evaluate such issues . The P-MASS is a small payload that is designed to meet the mass (40 lbs.), volume (1.5 cu.ft.), and power (120 W) constraints of one of several COMET payloads while enabling flight evaluations of plants, algae and bacteria . Various P-MASS subsystems have been subjected to extensive ground tests as well as KCl35 tests . Various biological sub-systems have been similarly evaluated . Through a variety of sensors coupled with color video, the P-MASS performance and the supported biological systems will be compared for terrestrial controls versus spaceflight materials . This small, low cost payload should return valuable information regarding the requirements for hardware and biological systems needed to move toward bioregenerative life support systems in space . In addition, it should be possible to accurately identify major unresolved difficulties that may arise in the long-term, spaceflight support of various biological systems . Finally, this generic spaceflight capability should enable a variety of plant research programs focused on the use of microgravity to modulate and exploit plant products for commercial applications ranging from new agricultural products to pharmacological feedstocks and new controlled agricultural strategies. Adv Space Res, 1994 Nov, 14(11), 135 - 42 Indications and counterindications for applying different versions of closed ecosystems for space and terrestrial problems of life support; Mezhevikin VV et al.; Different versions of manned closed ecosystems (CES) based on photosynthesis of unicellular and/or higher plants and chemosynthesis or bacteria are considered . Different versions of CES have been compared for applying them on Earth, Moon, Mars and Venus orbital stations, for Mars missions and planetary stations as well as to provide high-quality life in extreme conditions on the Earth . In microgravity {correction of mycrogravity} we recommend CES with unicellular organisms based on photosynthesis or chemosynthesis (depending of the availability of the light or electric energy) . For the planetary stations with Moon gravity and higher CES with higher plants are recommended . Improvement of indoor air quality by CES biotechnology is considered. J R Astron Soc Can, 1996 Aug, 90(4), 184 - 92 Astrophysical and biological constraints on radiopanspermia; Secker J et al.; We have carried out a series of calculations involving bacteria and viruses embedded in dust grains, which are ejected from our solar system by radiation pressure and travel through space to other star systems . Under many conditions this type of panspermia is impractical, primarily because the ultraviolet (UV) radiation of the present Sun inactivates the micro-organisms . However, if the organisms are shielded by an absorbing material like carbon and if ejection takes place in the red-giant phase of a one solar mass star like our Sun, there is a significant probability that the micro-organisms can reach another star system alive (i.e . with only sub-lethal damage from UV and ionizing radiation) . In addition to panspermia with viable micro-organisms, it is possible to seed the Galaxy with inactivated ones whose DNA and RNA fragments may provide the initial information necessary to start biological evolution in favourable environments. Geology, 1994 May, 22, 387 - 90 Abiological origin of described stromatolites older than 3.2 Ga; Lowe DR; The three well-documented occurrences of three-dimensional stromatolites older than 3.2 Ga meet most criteria for biogenicity except the presence of fossil bacteria . However, they also show features more consistent with nonbiological origins . Small conical structures in the Strelley Pool chert in the upper part of the Warrawoona Group (3.5-3.2 Ga), Western Australia, lack the structure typical of stromatolites and probably formed mainly through evaporitc precipitation . A domal structure from the North Pole chert, Warrawoona Group, formed by soft-sediment deformation or originally flat layers . Laminated chert containing domal and pseudocolumnar structures in the Onverwacht Group (3.5-3.3 Ga), Barberton Greenstone Belt, South Africa, extends downward into veins and cavities, where it formed through inorganic precipitation . Although bacterial communities were widespread on Earth prior to 3.2 Ga, these particular three-dimensional structures are probably abiotic in origin and do not provide information on the paleobiology or paleoecology of early organisms . The paucity of Archean stromatolites older than 3.2 Ga probably reflects the paucity of known and possibly extant carbonate deposits of this age. J Phys Chem B Condens Matter Mater Surf Interfaces Biophys, 1997 May 15, 101(20), 4136 - 41 Time-resolved spectroscopy of energy transfer and trapping upon selective excitation in membranes of Heliobacillus mobilis at low temperature; Chiou HC et al.; Transient absorption difference spectra in the Qy absorption band of bacteriochlorophyll (BChl) g and in the 670 nm absorption band of the primary acceptor A0 in membranes of Heliobacillus mobilis (Hc . mobilis) were measured at 20 K upon selective excitation at 668, 793, 810, and 815 nm with a 5 nm spectral bandwidth . When excited at 793 nm, the spectral equilibration of excitations from shorter to longer wavelength-absorbing pigments occurred within 3 ps and mostly localized at the band centered around 808 nm . When excited at 668 nm, the excitation energy transfer from the 670 nm absorbing pigment to the Qy band of BChl g took less than 0.5 ps, and the energy redistribution occurred and localized at 808 nm as in the case of the 793 nm excitation . All of the excitations were localized at the long wavelength pigment pool centered around 810 or 813 nm when excited at 810 or 815 nm . A slower energy transfer process with a time constant of 15 ps was also observed within the pool of long wavelength-absorbing pigments upon selective excitation at different wavelengths as has been observed by Lin et al . (Biophys . J . 1994, 67, 2479) when excited at 590 nm . Energy transfer from long wavelength antenna molecules to the primary electron donor P798 followed by the formation of P+ took place with a time constant of 55-70 ps for all excitations . Direct excitation of the primary electron acceptor A0, which absorbed at 670 nm, showed the same kinetic behavior as in the case when different forms of antenna pigments were excited in the Qy region . This observation generally supports the trapping-limited case of energy transfer in which the excitations have high escape probability from the reaction center (RC) until the charge separation takes place . Possible mechanisms to account for the apparent "uphill" energy transfer from the long wavelength antenna pigments to P798 are discussed. Geochim Cosmochim Acta, 1995, 59(9), 1895 - 900 Evidence for gammacerane as an indicator of water column stratification; Sinninghe Damste JS et al.; A new route for the formation of gammacerane from tetrahymanol is proposed; in addition to dehydration and hydrogenation, sulphurisation and early C-S cleavage are shown to be important in the pathway of formation, especially in marine sediments . Evidence is twofold . First, relatively large amounts of the gammacerane skeleton are sequestered in S-rich macromolecular aggregates formed by natural sulphurisation of functionalised lipids . Selective cleavage of polysulphide linkages with MeLi/MeI led to formation of 3-methylthiogammacerane, indicating that the gammacerane skeleton is primarily bound via sulphur at position 3, consistent with the idea that tetrahymanol (or the corresponding ketone) is the precursor for gammacerane . Second, upon mild artificial maturation of two sediments using hydrous pyrolysis, gammacerane is released from S-rich macromolecular aggregates by cleavage of the relatively weak C-S bonds . The stable carbon isotopic compositions of gammacerane and lipids derived from primary producers and green sulphur bacteria in both the Miocene Gessoso-solfifera and Upper Jurassic Allgau Formations indicate that gammacerane is derived from bacterivorous ciliates which were partially feeding on green sulphur bacteria . This demonstrates that anaerobic ciliates living at or below the chemocline are important sources for gammacerane, consistent with the fact that ciliates only biosynthesize tetrahymanol if their diet is deprived of sterols . This leads to the conclusion that gammacerane is an indicator for water column stratification, which solves two current enigmas in gammacerane geochemistry . Firstly, it explains why gammacerane is often found in sediments deposited under hypersaline conditions but is not necessarily restricted to this type of deposits . Secondly, it explains why lacustrine deposits may contain abundant gammacerane since most lakes in the temperate climatic zones are stratified during summer. Planet Rep, 1991, Mar-Apr, 8 - 11 From Siberia to Mars McKay CP, Friedmann EI, Meyer MA. Because Mars is so similar to Earth, planetary scientists looking for answers to questions like these often use analogous environments on Earth to help them design future Mars missions . Such terrestrial sites, however remote, are still much more accessible than Mars . Field studies in such places give us a chance to test and refine instruments and procedures, develop overall concepts and collect baseline data to compare with actual results from Mars . Perhaps the best terrestrial analogue to the martian permafrost lies in northeastern Siberia . Freezing conditions have persisted here for over 3 million years . Although young by martian standards, these are among the oldest continuously frozen localities on Earth . They also hold something remarkable: not only organic residues, but also large numbers of viable bacteria (up to 100 million per gram of frozen soil), preserved for 3 million years in ice. Org Geochem, 1992 Dec, 19(1-3), 265 - 76 An isotopic biogeochemical study of the Green River oil shale; Collister JW et al.; Thirty-five different samples from three different sulfur cycles were examined in this stratigraphically oriented study of the Shell 22x-l well (U.S.G.S . C177 core) in the Piceance Basin, Colorado . Carbon isotopic compositions of constituents of Green River bitumens indicate mixing of three main components: products of primary photoautotrophs and their immediate consumers (delta approximately -30% vs PDB), products of methanotrophic bacteria (delta approximately -85%), and products of unknown bacteria (delta approximately -40%) . For individual compounds synthesized by primary producers, delta-values ranged from -28 to -32% . 13C contents of individual primary products (beta-carotane, steranes, acyclic isoprenoids, tricyclic triterpenoids) were not closely correlated, suggesting diverse origins for these materials . 13C contents of numerous hopanoids were inversely related to sulfur abundance, indicating that they derived both from methanotrophs and from other bacteria, with abundances of methanotrophs depressed when sulfur was plentiful in the paleoenvironment . gamma-Cerane coeluted with 3 beta(CH3),17 alpha(H),21 beta(H)-hopane, but delta-values could be determined after deconvolution . gamma-Cerane (delta approximately -25%) probably derives from a eukaryotic heterotroph grazing on primary materials, the latter compound (delta approximately -90%) must derive from methanotrophic organisms . 13C contents of n-alkanes in bitumen differed markedly from those of paraffins generated pyrolytically . Isotopic and quantitative relationships suggest that alkanes released by pyrolysis derived from a resistant biopolymer of eukaryotic origin and that this was a dominant constituent of total organic carbon. J Microbiol Methods, 1992 Oct, 16(2), 157 - 67 A novel directly coupled gradostat; Wimpenny JW et al.; The original bidirectional compound chemostat (gradostat) described by Lovitt and Wimpenny has been simplified by making a more compact apparatus in which chemical gradients are established by diffusion between adjacent culture chambers . The experimental model (diffusion coupled (DC) gradostat) consisted of five chambers whose contents could be agitated by turbines rotating in the horizontal plane on a common shaft . Two biological experiments were designed to reveal the value of the DC gradostat . A methylotroph (Methylophilus methylotrophus) grown in a methanol gradient showed expected changes in cell viability as a function of position in the five vessel array . Cells of two species of photosynthetic bacteria (Rhodobacter capsulata and Rhodopseudomonas marina/agilis) with different salt sensitivities could be mixed and subsequently separated by the DC gradostat operating with a NaCl gradient of 0-3% w/v. Adv Space Res, 1994 Oct, 14(10), 1005 - 19 Cellular changes in microgravity and the design of space radiation experiments; Morrison DR; Cell metabolism, secretion and cell-cell interactions can be altered during space flight . Early radiobiology experiments have demonstrated synergistic effects of radiation and microgravity as indicated by increased mutagenesis, increased chromosome aberrations, inhibited development, and retarded growth . Microgravity-induced changes in immune cell functions include reduced blastogenesis and cell-mediated, delayed-type hypersensitivity responses, increased cytokine secretions, but inhibited cytotoxic effects and macrophage differentiation . These effects are important because of the high radiosensitivity of immune cells . It is difficult to compare ground studies with space radiation biology experiments because of the complexity of the space radiation environment, types of radiation damage and repair mechanisms . Altered intracellular functions and molecular mechanisms must be considered in the design and interpretation of space radiation experiments . Critical steps in radiocarcinogenesis could be affected . New cell systems and hardware are needed to determine the biological effectiveness of the low dose rate, isotropic, multispectral space radiation and the potential usefulness of radioprotectants during space flight. Photosynth Res, 1994 Jul, 41(1), 115 - 23 Spectroscopic evidence for the presence of an iron-sulfur center similar to Fx of Photosystem I in Heliobacillus mobilis; Kleinherenbrink FA et al.; Treatment of membranes of Heliobacillus mobilis with high concentrations of the chaotropic agent urea resulted in the removal of the iron-sulfur centers FA and FB from the reaction center, as indicated by EPR spectra under strongly reducing conditions . In urea-treated membranes, transient absorption measurements upon a laser flash indicated a recombination between the photo-oxidized primary donor P798+ and a reduced acceptor with a time constant of 20 ms at room temperature . Benzylviologen, vitamin K-3 and methylene blue were found to accept electrons from the reduced acceptor efficiently . A differential extinction coefficient of 225-240 mM-1 cm-1 at 798 nm was determined from experiments in the presence of methylene blue . Transient absorption difference spectra between 400 and 500 nm in the presence and absence of artificial acceptors indicated that the electron acceptor involved in the 20 ms recombination has an absorption spectrum similar to that of an iron-sulfur center . This iron-sulfur center was assigned to be analogous to Fx of Photosystem I . Our results provide evidence in support of the presence of Fx in heliobacteria, which was proposed on the basis of the reaction center polypeptide sequence (Liebl et al . (1993) Proc . Natl . Acad . Sci . USA 90: 7124-7128) . Implications for the electron transfer pathway in the reaction center of heliobacteria are discussed. Planta, 1987, 171, 321 - 31 Thioredoxin and NADP-thioredoxin reductase from cultured carrot cells; Johnson TC et al.; Dark-grown carrot (Daucus carota L.) tissue cultures were found to contain both protein components of the NADP/thioredoxin system--NADP-thioredoxin reductase and the thioredoxin characteristic of heterotrophic systems, thioredoxin h . Thioredoxin h was purified to apparent homogeneity and, like typical bacterial counterparts, was a 12-kdalton (kDa) acidic protein capable of activating chloroplast NADP-malate dehydrogenase (EC 1.1.1.82) more effectively than fructose-1,6-bisphosphatase (EC 3.1.3.11) . NADP-thioredoxin reductase (EC 1.6.4.5) was partially purified and found to be an arsenite-sensitive enzyme composed of two 34-kDa subunits . Carrot NADP-thioredoxin reductase resembled more closely its counterpart from bacteria rather than animal cells in acceptor (thioredoxin) specificity . Upon greening of the cells, the content of NADP-thioredoxin-reductase activity, and, to a lesser extent, thioredoxin h decreased . The results confirm the presence of a heterotrophic-type thioredoxin system in plant cells and raise the question of its physiological function. Adv Space Res, 1984, 4(10), 231 - 5 Effect of secondary radiation produced by 70 GeV protons on DNA of mammalian cells; Leont'eva GA et al.; It is shown that the RBE of the 70 GeV proton secondary radiation for the induction of single-strand break is 1.6-7.6 in Chinese hamster fibroblasts and 1.04-3.8 in limphoid cells and for the lethality of Chinese hamster cells 1.14-1.7 . The RBE value increases with decreasing dose of the secondary radiation . On post-irradiation incubation of mammalian cells at 37 degrees C, single-strand breaks induced by the secondary radiation are repaired with the sane time course as those induced by gamma-rays . In our earlier works we have made an attempt to estimate the biological efficiency of radiation generated by the 70 GeV protons on bacteria, phage T4 and Vicia faba beans . The obtained values of the relative biological efficiency (RBE) of this radiation varied between 1.4 and 5.5, depending on the object, criterion of estimation, times of registration and other experimental conditions . The aim of the present work is to estimate the biological efficiency of synchrotron radiation by its effect on mammalian cells. Trends Ecol Evol, 1994 Oct, 9(10), 375 - 7 The early evolution of life: solution to Darwin's dilemma; Schopf JW; NASA: Recent studies of Precambrian fossils indicate that life on Earth originated earlier than assumed, microscopic life was prevalent in the Precambrian Eon, the tempo and mode of evolution during the Precambrian period were different from other periods, and that only the Precambrian fossil record can be used as evidence of early life . Implications for future research include directing the search for the origin of life away from the geological record, modification of hypotheses about molecular change, use of Precambrian microfossils in dating younger geological units, and progress in defining the nature of major events in early evolution . Acta Astronaut, 1994 Jul, 33, 167 - 77 C.E.B.A.S.-AQUARACK project: the Mini-Module as tool in artificial ecosystem research; Blum V et al.; The evolution of the C.E.B.A.S-AQUARACK project including results of the scientific frame program was frequently presented at the IAA Man in Space Symposia 1989 and 1991 and the IAF/IAA congresses since 1990 . C.E.B.A.S . (Closed Equilibrated Biological Aquatic System) is a combined animal/plant system for long-term multi-generation experiments with aquatic organisms in ground laboratories and in a space station . For short-term missions a miniaturized version was developed which fits into a spacelab middeck locker together with all surrounding equipment . The latest development is an optimized prototype with a total volume of about 11 liters which consists of a main animal tank (Zoological Component) with integrated bacteria filter, a semibiological coarse filter, an illuminated higher plant container (Botanical Component) and combined small animal and electrode compartment . A silastic tubing gas exchanger in a closed side-loop serves as an emergency unit in case of the malfunction of the Botanical Component and the water is driven through the system by rotatory pumps . It is operative for several weeks in closed state . This C.E.B.A.S . Mini-Module also represents an aquatic artificial ecosystem in which basic scientific problems of component interactions and system theory can be solved with the side aspects of combined production of animal and plant food in bioregenerative life support systems . The paper presents details of the current status of the hardware development and data about the function of the fully biological life support of the system, e . g . mid-term registrations of water parameters . Moreover, morphological and physiological data of the experimental animals (-the teleost fish Xiphophorus helleri-) and plants (-a tropical Ceratophyllum species-) demonstrate the biological stability of the system . These are used to elaborate first details of population interactions and inter-dependencies as a basis of a disposed comprehensive system analysis which is the essential precondition for the design of possible aquatic modules for bioregenerative life support systems. Science, 1993 Oct 22, 262, 555 - 7 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence; Ohmoto H et al.; Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate . These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>>10(-13) of the present atmospheric level) of free oxygen. Org Geochem, 1993, 20(8), 1253 - 63 Molecular and bulk isotopic analyses of organic matter in marls of the Mulhouse Basin (Tertiary, Alsace, France); Hollander DJ et al.; Contents of 13C in kerogens and carbonates in 21 samples from a core of the MAX borehole, Mulhouse Evaporite Basin, range from -27.3 to -23.5 and -3.7 to -1.8% vs PDB, respectively . Organic nitrogen in the same samples is enriched in 15N relative to atmospheric N2 by 12.2-15.7% . Hydrogen indices and delta values for kerogens vary systematically with facies, averaging 493 mg HC/g Corg and -25.7% in the most saline facies (dominated by inputs from aquatic sources) and 267 mg HC/g Corg and -23.7% in the least saline facies (50/50 aquatic/terrigenous) . Values of delta were measured for individual aliphatic hydrocarbons from three samples representing three different organic facies . For all samples, terrigenous inputs were unusually rich in 13C, the estimated delta value for bulk terrigenous debris, apparently derived partly from CAM plants, being -22.5% . In the most saline facies, isotopic evidence indicates the mixing of 13C-depleted products of photosynthetic bacteria with 13C-enriched products of halotolerant eukaryotic algae . At lower salinities, a change in the producer community is marked by a decrease in the 13C content of algal lipids . The content of 13C in algal lipids increases in the least saline facies, due either to succession of different organisms or to decreased concentrations of dissolved CO2. Org Geochem, 1994, 21(6-7), 645 - 59 Partial resolution of sources of n-alkanes in the saline portion of the Parachute Creek Member, Green River Formation (Piceance Creek Basin, Colorado); Collister JW et al.; Systematic variations in the 13C contents of individual extractable n-alkanes (C16-C29) can be modelled quantitatively and interpreted as indicating contributions from at least five distinct sources . These appear to be cyanobacterial (C16-C18, delta 13C = -37% vs PDB), phytoplanktonic (C16-C23, delta = -32%), chemoautotrophic bacterial (C20-C29, delta = -38%), phytoplanktonic or heterotrophic bacterial (C20-C29, delta = -30%), and vascular plants (C23-C29, delta = -29%) . Hydrous pyrolysis of related kerogens yields large quantities of additional n-alkanes with different and much more uniform delta values . The latter materials are apparently derived from the thermolysis of aliphatic biopolymers whose presence in the Green River Oil Shale has been recognized visually. Org Geochem, 1994, 21(6-7), 629 - 44 Predictive isotopic biogeochemistry: hydrocarbons from anoxic marine basins; Freeman KH et al.; Carbon isotopic compositions were determined for individual hydrocarbons in water column and sediment samples from the Cariaco Trench and Black Sea . In order to identify hydrocarbons derived from phytoplankton, the isotopic compositions expected for biomass of autotrophic organisms living in surface waters of both localities were calculated based on the concentrations of CO2(aq) and the isotopic compositions of dissolved inorganic carbon . These calculated values are compared to measured delta values for particulate organic carbon and for individual hydrocarbon compounds . Specifically, we find that lycopane is probably derived from phytoplankton and that diploptene is derived from the lipids of chemoautotrophs living above the oxic/anoxic boundary . Three acyclic isoprenoids that have been considered markers for methanogens, pentamethyleicosane and two hydrogenated squalenes, have different delta values and apparently do not derive from a common source . Based on the concentration profiles and isotopic compositions, the C31 and C33 n-alkanes and n-alkenes have a similar source, and both may have a planktonic origin . If so, previously assigned terrestrial origins of organic matter in some Black Sea sediments may be erroneous. J Phys Chem, 1996 May 16, 100(20), 8573 - 9 Qy-excitation resonance Raman spectra of chlorophyll a and bacteriochlorophyll c/d aggregates . Effects of peripheral substituents on the low-frequency vibrational characteristics; Diers JR et al.; Low-frequency (80-700 cm-1) Qy-excitation resonance Raman (RR) spectra are reported for thin-solid-film aggregates of several chlorophyll (Chl) a and bacteriochlorophyll (BChl) c/d pigments . The pigments include Chl a, pyrochlorophyll a (PChl a), methylpyrochloropyllide a (MPChl a), methylbacteriochloropyllide d (MBChl d), {E,M} BChl cS, {E,E} BChl cF, and {P,E} BChl cF . The BChl c/d's are the principal constituents of the chlorosomal light-harvesting apparatus of green photosynthetic bacteria . Together, the various Chl a's and BChl c/d's represent a series in which the peripheral substituent groups on the chlorin macrocycle are varied in systematic fashion . All of the Chl a and BChl c/d aggregates exhibit rich low-frequency vibrational patterns . In the case of the BChl c/d's, certain modes in the very low-frequency region (100-200 cm-1) experience exceptionally strong Raman intensity enhancements . The frequencies of these modes are qualitatively similar to those of oscillations observed in femtosecond optical experiments on chlorosomes . The RR data indicate that the low-frequency vibrations are best characterized as intramolecular out-of-plane deformations of the chlorin macrocycle rather than intermolecular modes . The coupling of the out-of-plane modes in turn implies that the Qy electronic transition(s) of the aggregate have out-of-plane character . The RR spectra of the BChl c/d's also reveal that the nature of the alkyl substituents at the 8 and 12 positions of the macrocycle plays an important role in determining the detailed features of the low-frequency vibrational patterns . The frequencies of the modes are particularly sensitive to larger substituent groups whose conformations may be more easily perturbed in the tightly packed aggregates . These factors also make aggregates of pigments containing larger substituents more susceptible to structural, electronic, and vibrational inhomgeneities . Collectively, the RR studies of the various pigments delineate the factors which influence the low-frequency vibrational characteristics of chlorosomal aggregates. Chem Geol, 1994, 114, 315 - 29 Factors influencing organic carbon preservation in marine sediments; Canfield DE; The organic matter that escapes decomposition is buried and preserved in marine sediments, with much debate as to whether the amount depends on bottom-water O2 concentration . One group argues that decomposition is more efficient with O2, and hence, organic carbon will be preferentially oxidized in its presence, and preserved in its absence . Another group argues that the kinetics of organic matter decomposition are similar in the presence and absence of O2, and there should be no influence of O2 on preservation . A compilation of carbon preservation shows that both groups are right, depending on the circumstances of deposition . At high rates of deposition, such as near continental margins, little difference in preservation is found with varying bottom-water O2 . It is important that most carbon in these sediments decomposes by anaerobic pathways regardless of bottom-water O2 . Hence, little influence of bottom-water O2 on preservation would, in fact, be expected . As sedimentation rate drops, sediments deposited under oxygenated bottom water become progressively more aerobic, while euxinic sediments remain anaerobic . Under these circumstances, the relative efficiencies of aerobic and anaerobic decomposition could affect preservation . Indeed, enhanced preservation is observed in low-O2 and euxinic environments . To explore in detail the factors contributing to this enhanced carbon preservation, aspects of the biochemistries of the aerobic and anaerobic process are reviewed . Other potential influences on preservation are also explored . Finally, a new model for organic carbon decomposition, the "pseudo-G" model, is developed . This model couples the degradation of refractory organic matter to the overall metabolic activity of the sediment, and has consequences for carbon preservation due to the mixing together of labile and refractory organic matter by bioturbation. Adv Space Res, 1995 Mar, 15(3), 345 - 56 On the levels of enzymatic substrate specificity: implications for the early evolution of metabolic pathways; Lazcano A et al.; The most frequently invoked explanation for the origin of metabolic pathways is the retrograde evolution hypothesis . In contrast, according to the so-called "patchwork" theory, metabolism evolved by the recruitment of relatively inefficient small enzymes of broad specificity that could react with a wide range of chemically related substrates . In this paper it is argued that both sequence comparisons and experimental results on enzyme substrate specificity support the patchwork assembly theory . The available evidence supports previous suggestions that gene duplication events followed by a gradual neoDarwinian accumulation of mutations and other minute genetic changes lead to the narrowing and modification of enzyme function in at least some primordial metabolic pathways. Org Geochem, 1995 Jun, 23(6), 485 - 526 Molecular indicators for palaeoenvironmental change in a Messinian evaporitic sequence (Vena del Gesso, Italy) . II: High-resolution variations in abundances and 13C contents of free and sulphur-bound carbon skeletons in a single marl bed; Kenig F et al.; The extractable organic matter of 10 immature samples from a marl bed of one evaporitic cycle of the Vena del Gesso sediments (Gessoso-solfifera Fm., Messinian, Italy) was analyzed quantitatively for free hydrocarbons and organic sulphur compounds . Nickel boride was used as a desulphurizing agent to recover sulphur-bound lipids from the polar and asphaltene fractions . Carbon isotopic compositions (delta vs PDB) of free hydrocarbons and of S-bound hydrocarbons were also measured . Relationships between these carbon skeletons, precursor biolipids, and the organisms producing them could then be examined . Concentrations of S-bound lipids and free hydrocarbons and their delta values were plotted vs depth in the marl bed and the profiles were interpreted in terms of variations in source organisms, 13 C contents of the carbon source, and environmentally induced changes in isotopic fractionation . The overall range of delta values measured was 24.7%, from -11.6% for a component derived from green sulphur bacteria (Chlorobiaceae) to -36.3% for a lipid derived from purple sulphur bacteria (Chromatiaceae) . Deconvolution of mixtures of components deriving from multiple sources (green and purple sulphur bacteria, coccolithophorids, microalgae and higher plants) was sometimes possible because both quantitative and isotopic data were available and because either the free or S-bound pool sometimes appeared to contain material from a single source . Several free n-alkanes and S-bound lipids appeared to be specific products of upper-water-column primary producers (i.e . algae and cyanobacteria) . Others derived from anaerobic photoautotrophs and from heterotrophic protozoa (ciliates), which apparently fed partly on Chlorobiaceae . Four groups of n-alkanes produced by algae or cyanobacteria were also recognized based on systematic variations of abundance and isotopic composition with depth . For hydrocarbons probably derived from microalgae, isotopic variations are well correlated with those of total organic carbon . A resistant aliphatic biomacromolecule produced by microalgae is, therefore, probably an important component of the kerogen . These variations reflect changes in the depositional environment and early diagenetic transformations . Changes in the concentrations of S-bound lipids induced by variations in conditions favourable for sulphurization were discriminated from those related to variations in primary producer assemblages . The water column of the lagoonal basin was stratified and photic zone anoxia occurred during the early and middle stages of marl deposition . During the last stage of the marl deposition the stratification collapsed due to a significant shallowing of the water column . Contributions from anaerobic photoautotrophs were apparently associated with variations in depth of the chemocline. Org Geochem, 1994 Dec, 22(3-5), 703 - 25 A molecular and carbon isotopic study towards the origin and diagenetic fate of diaromatic carotenoids; Hartgers WA et al.; Pyrolysates of high-molecular-weight sedimentary fractions of the Duvernay Formation (Western Canada Basin) are dominated by 1,2,3,4- and 1,2,3,5-tetramethylbenzene, which, generated via beta-cleavage, indicate the presence of diaromatic carotenoids in the macromolecular aggregates . This was substantiated by desulphurization of sulphur-rich aggregates of the polar fraction, which released (partly) hydrogenated carotenoids . Furthermore, these components were important constituents of the aromatic hydrocarbon fractions and related oils . Apart from renieratane and isorenieratane, 1H NMR analysis established the aromatic substitution pattern of the most abundant component present, which was identified as a diaromatic compound with an unprecedented 2,3,6-/3,4,5-trimethyl aromatic substitution pattern . Molecular and isotopic analyses of both soluble and insoluble fractions of organic matter revealed relationships between diagenetically-derived carotenoids found in bitumen and related oils and their precursors incorporated into high-molecular-weight fractions . Aryl isoprenoids, important components in extracts and oils, were apparently derived from thermal cracking of bound diaromatic carotenoids rather than cleavage of free carotenoids as previously suggested . Furthermore, products derived from diaromatic carotenoids were substantially enriched in 13C relative to n-alkanes of algal origin . Together with the characteristic carotenoids, this isotopic enrichment provides evidence of significant contributions from photosynthetic green sulphur bacteria (Chlorobiaceae), which fix carbon via the reversed tricarboxylic acid (TCA) cycle . In spite of the prominence of these molecular signals, the overall isotopic composition of the organic matter indicated that only a very small portion of the preserved organic carbon was derived from the biomass of photosynthetic green sulphur bacteria. HortScience, 1987 Oct, 22(5), 873 - 4 The effects of nutrient solution sterilization on the growth and yield of hydroponically grown lettuce; Schwartzkopf SH et al.; Two methods of removing bacteria from hydroponic nutrient solution {ultraviolet (UV) radiation and submicronic filter} were evaluated for efficiency and for their effects on lettuce (Lactuca sativa L.) production . Both methods were effective in removing bacteria; but, at high intensity, the ultraviolet sterilizer significantly inhibited the production of plants grown in the treated solution . Bacterial removal by lower intensity UV or a submicronic filter seemed to promote plant growth slightly, but showed no consistent, statistically significant effect. Annu Rev Earth Planet Sci, 1990, 18, 317 - 56 The origin and early evolution of life on Earth; Oro J et al.; NASA: We do not have a detailed knowledge of the processes that led to the appearance of life on Earth . In this review we bring together some of the most important results that have provided insights into the cosmic and primitive Earth environments, particularly those environments in which life is thought to have originated . To do so, we first discuss the evidence bearing on the antiquity of life on our planet and the prebiotic significance of organic compounds found in interstellar clouds and in primitive solar system bodies such as comets, dark asteroids, and carbonaceous chondrites . This is followed by a discussion on the environmental models of the Hadean and early Archean Earth, as well as on the prebiotic formation of organic monomers and polymers essential to life . We then consider the processes that may have led to the appearance in the Archean of the first cells, and how these processes may have affected the early steps of biological evolution . Finally, the significance of these results to the study of the distribution of life in the Universe is discussed . NASA Edited Photosynth Res, 1992, 32, 11 - 22 Protein sequences and redox titrations indicate that the electron acceptors in reaction centers from heliobacteria are similar to Photosystem I; Trost JT et al.; Photosynthetic reaction centers isolated from Heliobacillus mobilis exhibit a single major protein on SDS-PAGE of 47 000 Mr . Attempts to sequence the reaction center polypeptide indicated that the N-terminus is blocked . After enzymatic and chemical cleavage, four peptide fragments were sequenced from the Heliobacillus mobilis apoprotein . Only one of these sequences showed significant specific similarity to any of the protein and deduced protein sequences in the GenBank data base . This fragment is identical with 56% of the residues, including both cysteines, found in highly conserved region that is proposed to bind iron-sulfur center Fx in the Photosystem I reaction center peptide that is the psaB gene product . The similarity to the psaA gene product in this region is 48% . Redox titrations of laser-flash-induced photobleaching with millisecond decay kinetics on isolated reaction centers from Heliobacterium gestii indicate a midpoint potential of -414 mV with n = 2 titration behavior . In membranes, the behavior is intermediate between n = 1 and n = 2, and the apparent midpoint potential is -444 mV . This is compared to the behavior in Photosystem I, where the intermediate electron acceptor A1, thought to be a phylloquinone molecule, has been proposed to undergo a double reduction at low redox potentials in the presence of viologen redox mediators . These results strongly suggest that the acceptor side electron transfer system in reaction centers from heliobacteria is indeed analogous to that found in Photosystem I . The sequence similarities indicate that the divergence of the heliobacteria from the Photosystem I line occurred before the gene duplication and subsequent divergence that lead to the heterodimeric protein core of the Photosystem I reaction center. Photosynth Res, 1992, 33, 91 - 111 Origin and early evolution of photosynthesis; Blankenship RE; Photosynthesis was well-established on the earth at least 3.5 thousand million years ago, and it is widely believed that these ancient organisms had similar metabolic capabilities to modern cyanobacteria . This requires that development of two photosystems and the oxygen evolution capability occurred very early in the earth's history, and that a presumed phase of evolution involving non-oxygen evolving photosynthetic organisms took place even earlier . The evolutionary relationships of the reaction center complexes found in all the classes of currently existing organisms have been analyzed using sequence analysis and biophysical measurements . The results indicate that all reaction centers fall into two basic groups, those with pheophytin and a pair of quinones as early acceptors, and those with iron sulfur clusters as early acceptors . No simple linear branching evolutionary scheme can account for the distribution patterns of reaction centers in existing photosynthetic organisms, and lateral transfer of genetic information is considered as a likely possibility . Possible scenarios for the development of primitive reaction centers into the heterodimeric protein structures found in existing reaction centers and for the development of organisms with two linked photosystems are presented. Isot Geosci, 1988, 73, 205 - 10 Sulfur isotope effects associated with oxidation of sulfide by O2 in aqueous solution; Fry B et al.; Normal sulfur isotope effects averaging epsilon = -5.2 +/- 1.4% (s.d.) were consistently observed for the oxidation of sulfide in aqueous solution . Reaction products were sulfate, thiosulfate and sulfite at pH 10.8-11 in distilled water; S0 was formed in two experiments with synthetic seawater at pH 8-9.5 . Because the -5.2% normal isotope effect differs significantly from the previously measured +2% inverse effect associated with anaerobic oxidation of sulfide by photosynthetic bacteria, stable sulfur isotopic measurements are potentially useful for distinguishing aerobic vs . anaerobic sulfide oxidation in marine and freshwater sulfureta. Space Technol, 1989, 9(1-2), 41 - 5 Research on Biolab, a multi-user facility for APM; Cogoli M et al.; A study carried out by a team of seven scientists appointed by ESA resulted in the design of a biological laboratory "Biolab" for Columbus APM . The basis for the study were four pre-Phase A studies performed by industry on the assumption that 15 racks would be available to biology and biotechnology in the APM . Due to the constraints newly imposed by the Columbus project, only five racks are now allocated . The tasks of the Biolab scientific team were: (i) to define the scientific objectives of biological research in Columbus; (ii) to review the requirements of the industrial studies; and (iii) to design a multi-purpose facility compatible with the present constraints and satisfying the requirements of the biological investigations considered in the four studies . The Biolab team was able to define a facility capable of accommodating in five racks the following biological objects: small plants (up to 40 cm), insects like drosophila, frog eggs, single cells from animals, bacteria, slime molds and protozoa, as well as human physiology, but restricted to general diagnostic needs . The Biolab facility includes instruments and devices providing the capacity of holding and/or growing the organisms as well as to perform basic experimentation and a minimum essential diagnostic inflight . Within the growth unit the growth chambers/incubators are exchangeable, permitting the use of growth chambers of different sizes . The temperature will be adjustable to the requirements of the objects under investigation, i.e . either 20 or 37 degrees C . Thus a considerable level of flexibility will permit to investigate a broad spectrum of living systems. Symbiosis, 1991, 11, 93 - 101 Bellagio conference and book . Symbiosis as Source of Evolutionary Innovation: Speciation and Morphogenesis . Conference--June 25-30, 1989, Bellagio Conference Center, Italy; Margulis L et al.; NASA: This conference at the Bellagio Conference Center, Italy, from June 25-30, 1989, provided a unique opportunity for evolutionary theorists and symbiosis biologists to cross the boundaries of their respective disciplines and share ideas . A major task was to address the adequacy of the prevailing neodarwinian concept of evolution with respect to the relative importance of symbiosis in the origin of morphological and evolutionary novelty . NASA Edited New Sci, 1991 Mar 23, 1761, 46 - 50 Kingdoms in turmoil; Margulis L et al.; How should the world's living organisms be classified? Into how many kingdoms should they be grouped? Scientists have been grappling with these questions since the time of Aristotle, drawing on a broad base of biological characteristics for clues . The fossil record, visible traits of living organisms and, more recently, results from cell biology have all shaped theories of biological classification . But last year a new and controversial concept emerged: a classification of life based solely on molecular traits . The focal point of the controversy is a tree of life, or "phylogeny", devised by Carl Woese of the University of Illinois, Otto Kandler of the University of Munich and Mark Wheelis of the University of California . The tree is unusual because, unlike all previous schemes, it is constructed solely from biochemical data such as DNA sequences rather than a range of different organism characteristics . But that is not all . The scheme also challenges the idea that life on Earth is best divided into five kingdoms, with the main split being between bacteria and all other organisms . Woese and his colleagues create three main groupings by dividing the bacteria in two and unifying all other organisms. J Phys Chem, 1993 May 27, 97(21), 5519 - 24 Optical spectroscopy of a highly fluorescent aggregate of bacteriochlorophyll c; Causgrove TP et al.; Bacteriochlorophyll (BChl) c and a similar model compound, Mg-methyl bacteriopheophorbide d, form several types of aggregates in nonpolar solvents . One of these aggregates is highly fluorescent, with a quantum yield higher than that of the monomer . This aggregate is also unusual in that it shows a rise time in its fluorescence emission decay at certain wavelengths, which is ascribed to a change in conformation of the aggregate . An analysis of fluorescence depolarization data is consistent with either a linear aggregate of four or five monomers or preferably a cyclic arrangement of three dimers. Photochem Photobiol, 1993, 57(2), 324 - 30 The photophysics of monomeric bacteriochlorophylls c and d and their derivatives: properties of the triplet state and singlet oxygen photogeneration and quenching; Krasnovsky AA Jr et al.; Measurements of pigment triplet-triplet absorption, pigment phosphorescence and photosensitized singlet oxygen luminescence were carried out on solutions containing monomeric bacteriochlorophylls (Bchl) c and d, isolated from green photosynthetic bacteria, and their magnesium-free and farnesyl-free analogs . The energies of the pigment triplet states fell in the range 1.29-1.34 eV . The triplet lifetimes in aerobic solutions were 200-250 ns; they increased to 280 +/- 70 microseconds after nitrogen purging in liquid solutions and to 0.7-2.1 ms in a solid matrix at ambient or liquid nitrogen temperatures . Rate constants for quenching of the pigment triplet state by oxygen were (2.0-2.5) x 10(9) M-1 s-1, which is close to 1/9 of the rate constant for diffusion-controlled reactions . This quenching was accompanied by singlet oxygen formation . The quantum yields for the triplet state formation and singlet oxygen production were 55-75% in air-saturated solutions . Singlet oxygen quenching by ground-state pigment molecules was observed . Quenching was the most efficient for magnesium-containing pigments, kq = (0.31-1.2) x 10(9) M-1 s-1 . It is caused mainly by a physical process of singlet oxygen (1O2) deactivation . Thus, Bchl c and d and their derivatives, as well as chlorophyll and Bchl a, combine a high efficiency of singlet oxygen production with the ability to protect photochemical and photobiological systems against damage by singlet oxygen. Photochem Photobiol, 1993, 57(1), 13 - 8 Lifetimes of bacteriochlorophyll fluorescence in Rhodopseudomonas viridis and Heliobacterium chlorum at low temperatures; Kleinherenbrink FA et al.; Fluorescence lifetimes of isolated membranes of Rhodopseudomonas viridis were measured in the temperature range of 77 K to 25 K . At room temperature, the main component of the fluorescence decay of bacteriochlorophyll (BChl) b had a time constant of 50 ps . In contrast to other purple bacteria, the emission at low temperature was spectrally homogeneous and showed essentially single lifetimes of 140 ps at 77 K and 180 ps at 25 K, with the primary electron donor in the oxidized state . Taking into account the relative fluorescence yields with open and closed reaction centers, we arrive at numbers of 125 ps and 215 ps, respectively, for open reaction centers . These numbers are significantly smaller than expected on the basis of measurements of the efficiency of charge separation, perhaps suggesting that the excitation decay in the absence of reaction centers is considerably faster at low temperature than at room temperature . At least four different spectral components with different lifetimes were observed at 25 K in the emission of Heliobacterium chlorum, a short-wavelength component of about 30 ps and three longer-wavelength components of about 100 ps, 300 ps, and 900 ps . This indicates a strong heterogeneity in the emitting pigment, BChl g-808 . The component with the shortest lifetime does not appear to be affected by the redox state of the reaction center and might reflect energy transfer to BChl g species which are connected to the reaction center. Adv Space Res, 1984, 4(12), 195 - 201 Cell symbiosis {correction of symbioisis} theory: status and implications for the fossil record; Margulis L et al.; Recent geological treatises have presented three alternative models of the origins of eukaryotes as if they merited equal treatment . However, modern biological techniques, especially nucleic acid and protein sequencing, have clearly established the validity of the symbiotic theory of the origin of eukaryotic organelles . The serial endosymbiotic theory in its most extreme form states that three classes of eukaryotic cell organelles (mitochondria, plastids and undulipodia) originated as free-living bacteria (aerobic respirers, phototrophic bacteria and spirochetes respectively) in association with hosts that become the nucleocytoplasm (Thermoplasma-like archaebacterial hosts) . Molecular biological information, primarily derived from ribosomal RNA nucleotide sequencing studies leads to the conclusion that the symbiotic origin theory for both mitochondria and plastids has been proven . The probability of an ancestral archaebacterial-Thermoplasma-like host for the nucleocytoplasm has been rendered more likely by discoveries by Dennis Searcy and his colleagues and Carl Woese and his colleagues . The most equivocal postulate of the symbiotic theory, the origin of undulipodia (cilia and other organelles of motility that develop from kinetosomes is under investigation now . The status of these postulates, as well as their implications for the fossil record, is briefly summarized here. Acta Astronaut, 1992 Jul, 27, 197 - 204 C.E.B.A.S.-AQUARACK: second generation hardware and latest scientific results; Bluem V et al.; A second version of the C.E.B.A.S.-AQUARACK laboratory prototype was developed which includes a new water recycling system and a "Botanical Component" with higher water plants for nitrate elimination . It was modified by a compact commercial filter system which involves a semi-biological coarse filter, a bacteria filter, gas and heat exchangers and a UV sterilization device . A highly sophisticated process control system offers all possibilities to implement robotics and telescience . With the installation of the Botanical component into the system the first step of the realisation of the conception of a "Closed Equilibrated Biological Aquatic System" is performed . In the scientific frame program the reproductive biology of the main experimental animal, Xiphophorus helleri, plays an important role . After the establishment of a morphological reference system of the stages of sexual maturity in both sexes this is correlated with relevant physiological data as concentrations of sexual steroids in gonadal tissue and plasma . On the brain-pituitary level the ontogeny of the gonadotropin releasing hormone (GnRH) and the gonadotropin (GtH) systems were investigated by immunohistochemistry . Surprisingly gonadotropin was not only localized in the pituitary gland but also in brain neurons and fibers which undergo a distinct ontogenetic development and a major part of which are in close structural relation to the GnRH system . A special chapter pays attention to the role of the C.E.B.A.S.-system in C.E.L.S.S . research. Orig Life Evol Biosph, 1991, 21, 157 - 63 Hydrogen peroxide and the evolution of oxygenic photosynthesis; McKay CP et al.; The early atmosphere of the Earth is considered to have been reducing (H2 rich) or neutral (CO2-N2) . The present atmosphere by contrast is highly oxidizing (20% O2) . The source of this oxygen is generally agreed to have been oxygenic photosynthesis, whereby organisms use water as the electron donor in the production of organic matter, liberating oxygen into the atmosphere . A major question in the evolution of life is how oxygenic photosynthesis could have evolved under anoxic conditions--and also when this capability evolved . It seems unlikely that water would be employed as the electron donor in anoxic environments that were rich in reducing agents such as ferrous or sulfide ions which could play that role . The abiotic production of atmospheric oxidants could have provided a mechanism by which locally oxidizing conditions were sustained within spatially confined habitats thus removing the available reductants and forcing photosynthetic organisms to utilize water as the electron donor . We suggest that atmospheric H2O2 played the key role in inducing oxygenic photosynthesis because as peroxide increased in a local environment, organisms would not only be faced with a loss of reductant, but they would also be pressed to develop the biochemical apparatus (e.g., catalase) that would ultimately be needed to protect against the products of oxygenic photosynthesis . This scenario allows for the early evolution of oxygenic photosynthesis while global conditions were still anaerobic. Adv Space Res, 1989, 9(6), 197 - 202 Planetary protection issues in advance of human exploration of Mars; McKay CP et al.; Current planetary quarantine considerations focus on robotic missions and attempt a policy of no biological contamination . The presence of humans on Mars, however, will inevitably result in biological contamination and physical alteration of the local environment . The focus of planetary quarantine must therefore shift toward defining and minimizing the inevitable contamination associated with humans . This will involve first determining those areas that will be affected by the presence of a human base, then verifying that these environments do not harbor indigenous life nor provide sites for Earth bacteria to grow . Precursor missions can provide salient information that can make more efficient the planning and design of human exploration missions . In particular, a robotic sample return mission can help to eliminate the concern about returning samples with humans or the return of humans themselves from a planetary quarantine perspective . Without a robotic return the cost of quarantine that would have to be added to a human mission may well exceed the cost of a robotic return mission . Even if the preponderance of scientific evidence argues against the presence of indigenous life, it must be considered as part of any serious planetary quarantine analysis for missions to Mars . If there is life on Mars, the question of human exploration assumes an ethical dimension. Adv Space Res, 1989, 9(11), 79 - 82 Ultrastructural and growth indices of Chlorella culture in multicomponent aquatic systems under space flight conditions; Popova AF et al.; Submicroscopic organization of Chlorella cells cultivated under space flight conditions in three-component aquatic system has been studied . Comparison of the experimental cells with that of the controls revealed certain rearrangements of cell organelles particularly, a reduction in the amount of reserve polysaccharides in chloroplasts, increase of cell vacuolization and mitochondrion volume, complication configuration of plasmalemma evaginations and invaginations, and also disturbances in the process of cytokinesis . More over an increase in the number of Chlorella cells infected by bacteria was shown in the experimental variant . No considerable differences were established in the growth characteristics of the experimental and control populations . A comparative cytological analysis revealed general regularities of organelles in Chlorella cells cultivated under space flight condition in the uni- and multicomponent systems. Adv Space Res, 1989, 9(10), 31 - 4 Stochastics of HZE-induced microlesions; Todd P; Fundamental biological experiments with bacteria, yeast, and mammalian cells irradiated with ions heavier than helium indicate that maximal probability of single-hit inactivation does not occur when the ion has LET below about 100-200 keV/micrometer . Theoretical treatments of cell inactivation data and the radiation chemistry in particle tracks are consistent with this finding . If a "microlesion" is defined as a linear array, within a tissue, of cells inactivated with maximum probability, surrounded by non-lethally damaged cells, then, by this definition, there must be an LET below which "microlesion" damage cannot be expected . In a retrospective survey of experimental literature in which single-particle effects in tissues were sought, it was found that little or no evidence has been reported supporting single-particle effects in tissues when LET was below 200 keV/micrometer, while some experimenters who irradiated tissues with particles having LET greater than 200 keV/micrometer reported effects that could be attributed to single-particle tracks. Adv Space Res, 1989, 9(10), 3 - 8 Radiation biology in space: a critical review; Hagen U; A short summary of the results of radiobiological studies in space or on respective particles on ground will be given . Among the various types of radiation in space, the effect of heavy ions with high energy (HZE-particles) are most essential . Thus, radiobiology in space concerns mostly to the effect of these particles, in cells and in whole organism . Cell death, mutation and malignant transformation are the relevant endpoints, with can be studied on ground with heavy ions of different energy with suitable accelerators or in space, especially by the BIOSTACK concept . In space, however, the effect of microgravity has to be considered as well and there are hints, that under weightlessness the biological effect of radiation may be enhanced . There are still open questions to be answered concerning radioprotection of man in space . Further experiments are necessary. Adv Space Res, 1989, 9(10), 197 - 201 Combined effects of radiation and trauma; Messerschmidt O; Injuries, caused by both whole-body irradiation and wounds or burns, have been relatively little studied . Possibly because many investigators think that these injuries are just modified radiation-induced diseases for which the same treatment principles are valid . Other authors had the impression that, for instance, the radiation burn trauma is a new kind of disease which differs significantly from either radiation syndrome alone or from burn disease . There are many experimental data on animals which suggest that the pathology of combined injuries differs significantly from that of radiation-induced disease or of thermal or mechanical traumas . Wounds or burns which, in general, do not cause septicaemia could become entrance ports for bacteria when animals are exposed to whole-body irradiation . Thrombocytopenia is the reason for hemorrhages in wounds . The susceptibility to shock is increased considerably in combined injuries and the formation of callus in the bone fractures is significantly delayed . The healing of wounds and burns in the initial phase of the radiation syndrome does not always differ from healing in the non-irradiated organism . However, a few days or weeks later very serious wound infections and hemorrhages can occur . The additional injuries almost always worsen the development and prognosis of radiation-induced disease . The recommended treatment for combined injuries will differ in many respects from the treatment of wounds and burns or the radiation syndrome. Adv Space Res, 1987, 7(4), 17 - 27 Operation of an experimental algal gas exchanger for use in a CELSS; Smernoff DT et al.; Concepts of a CELSS anticipate the use of photosynthetic organisms (higher plants and algae) for air revitalization . The rates of production and uptake of carbon dioxide and oxygen between the crew and the photosynthetic organisms are mismatched . An algal {correction of aglal} system used for gas exchange only will have the difficulty of an accumulation or depletion of these gases beyond physiologically tolerable limits (in a materially closed system the mismatch between assimilatory quotient (AQ) and respiratory quotient (RQ) will be balanced by the operation of the waste processor) . We report the results of a study designed to test the feasibility of using environmental manipulations to maintain physiologically appropriate atmospheres for algae (Chlorella pyrenoidosa) and mice (Mus musculus strain DW/J) in a gas-closed system . Specifically, we consider the atmosphere behavior of this system with Chlorella grown on nitrate or urea and at different light intensities and optical densities . Manipulation of both the photosynthetic rate and AQ of the alga has been found to reduce the mismatch of gas requirements and allow operation of the system in a gas-stable manner . Operation of such a system in a CELSS may be useful for reduction of buffer sizes, as a backup system for higher plant air revitalization and to supply extra oxygen to the waste processor or during crew changes . In addition, mass balance for components of the system (mouse, algae and a waste processor) are presented. Geochim Cosmochim Acta, 1990, 54, 247 - 51 Identification of the methylhopanes in sediments and petroleum; Summons RE et al.; Three C31 methylhopanes have been prepared by partial synthesis from appropriate diplopterol precursors . 2 alpha-Methyldiplopterol (prepared from 22-hydroxyhopan-3-one), 2 beta-methyldiplopterol (isolated from Methylobacterium organophilum), and a mixture of diplopterol and 3 beta-methyldiplopterol (isolated from Methylococcus capsulatus) were each converted to the corresponding 17 alpha(H), 21 beta(H)-hopane . Comparison of these standards, using gas chromatography--mass spectrometry with multiple reaction monitoring, with the hopanoids from a variety of bitumens showed that all three C31 hydrocarbons may occur in sediments and that they are members of C28 and C30-C36 pseudohomologous series . 2 alpha-Methyl-17 alpha(H), 21 beta(H)-hopane, and 3 beta-methyl-17 alpha(H), 21 beta(H)-hopane are most commonly encountered in mature bitumens . 2 beta-Methyl-17 alpha(H), 21 beta(H)-hopane occurs in some immature bitumens, is much less abundant in others of intermediate maturity, and appears to be absent from mature samples . This, and the similarity of the distribution patterns of homohopane and methylhomohopane isomers, indicates that the common sedimentary methylhopanes are probably derived from biogenic precursors via diagenetic processes analogous to those which give rise to hopanes . In the case of the 2 alpha-methyl series, common to petroleum and mature sediments, derivation from the 2 beta-methyl hopanoids found in certain bacteria implies a maturity-related change in the configuration at C-2. ASGSB Bull, 1991 Jul, 4(2), 133 - 46 The study of cells by optical trapping and manipulation of living cells using infrared laser beams; Ashkin A; The new technique of optical trapping and manipulation of living cells using the forces of radiation pressure from infrared single beam gradient laser traps is reviewed . These traps, also referred to as "optical tweezers," are capable of stably trapping transparent micron and submicron biological particles free of optical damage . Entire cells or organelles within the interior of living cells can be manipulated without damaging the cell wall . The trap is built into a high resolution microscope for combined trapping and high resolution viewing . Experiments demonstrating reproduction of motile bacteria and yeast cells within infrared traps and manipulations of plant and animal cells are discussed . Applications to the study of the mechanical properties of cell cytoplasm, study of cell function, and cell separation and orientation are considered . The ability to apply controlled light forces on cells of magnitude comparable to or often much greater than gravity suggests that these optical techniques might have relevance to experiments showing the influence of gravity on cells. Acta Astronaut, 1992 Mar-Apr, 26(3-4), 157 - 8 Recent advances in chemical evolution and the origins of life; Oro J et al.; This paper discusses the already 60 year old ideas of Oparin and Haldane, who suggested that the first forms of life were anaerobic, heterotrophic bacteria coming from chemical abiotic synthesis of organic compounds. Photochem Photobiol, 1996 Jul, 64(1), 32 - 7 Temperature dependence of charge recombination in Heliobacillus mobilis; Chiou HC et al.; Transient absorption difference spectroscopy was used to study the temperature dependence of the P798+ decay kinetics in heliobacteria . For membrane samples, two components were obtained from the fitting of kinetic traces in the temperature range of 4-29 degrees C . A 3-9 ms component representing the cytochrome (cyt) c oxidation has an activation energy of 33.0 +/- 2.8 kJ/mol . A 12-22 ms component representing either P798+FX- or P798+FA/B- recombination has an activation energy of 15.3 +/- 2.4 kJ/mol . In isolated reaction centers (RC), only one 14 ms component due to P798+FX- recombination was obtained in this temperature range . The Arrhenius plot shows that the recombination rate of this P798+FX- state is temperature independent in the near room temperature range . For RC in the temperature range of 60-298 K, a 12-15 ms decay was obtained at temperatures greater than 240 K . Biphasic decay traces (12-15 ms and 2-4 ms components) were obtained at temperatures between 170 K and 230 K . Only one 2-4 ms component was found at temperatures lower than 160 K . The gradual switchover from the 12-15 ms to the 2-4 ms component upon cooling may indicate the shift of the P798+FX- recombination state to a state that is prior to P798+FX-, although other interpretations can not be excluded . The absorption difference spectrum (delta A @ 160 K - delta A @ 240 K) in the blue region shows a positive amplitude below 405 nm and a negative amplitude above 405 nm implying that the 2-4 ms decay component may be due to the recombination of P798+A1-, where A1 is a quinone-type acceptor. Nature, 1996 Jul 11, 382(6587), 127 - 32 Late Proterozoic rise in atmospheric oxygen concentration inferred from phylogenetic and sulphur-isotope studies; Canfield DE et al.; The evolution of non-photosynthetic sulphide-oxidizing bacteria was contemporaneous with a large shift in the isotopic composition of biogenic sedimentary sulphides between 0.64 and 1.05 billion years ago . Both events were probably driven by a rise in atmospheric oxygen concentrations to greater than 5-18% of present levels--a change that may also have triggered the evolution of animals. FEMS Microbiol Lett, 1996 May 15, 139(1), 63 - 9 Structure and properties of novel inclusions in Shewanella putrefaciens; Krause B et al.; Cytoplasmic inclusions surrounded by a bilayer membrane were seen in thin sections . negatively stained and freeze-fractured preparations of Shewanella putrefaciens . Cells harvested from the late exponential and early stationary phase showed a higher number of these vesicles than bacteria isolated from early exponential or late stationary phase . Chemical dyes for polyphosphate or poly-beta-hydroxybutyrate did not stain the material enclosed within these vesicles . Elemental analysis of the material indicated that the content was organic in nature and might be a protein . HPLC analysis of the material showed that it was probably not a carbon source, nor an electron acceptor used by S . putrefaciens. Appl Environ Microbiol, 1995 Feb, 61(2), 576 - 82 Identification of methanotrophic lipid biomarkers in cold-seep mussel gills: chemical and isotopic analysis; Jahnke LL et al.; A lipid analysis of the tissues of a cold-seep mytilid mussel collected from the Louisiana slope of the Gulf of Mexico was used in conjunction with a compound-specific isotope analysis to demonstrate the presence of methanotrophic symbionts in the mussel gill tissue and to demonstrate the host's dependence on bacterially synthesized metabolic intermediates . The gill tissue contained large amounts of group-specific methanotrophic biomarkers, bacteriohopanoids, 4-methylsterols, lipopolysaccharide-associated hydroxy fatty acids, and type I-specific 16:1 fatty acid isomers with bond positions at delta 8, delta 10, and delta 11 . Only small amounts of these compounds were detected in the mantle or other tissues of the host animal . A variety of cholesterol and 4-methylsterol isomers were identified as both free and steryl esters, and the sterol double bond positions suggested that the major bacterially derived gill sterol {11.0% 4 alpha-methyl-cholesta-8(14),24-dien-3 beta-ol} was converted to host cholesterol (64.2% of the gill sterol was cholest-5-en-3 beta-ol) . The stable carbon isotope values for gill and mantle preparations were, respectively, -59.0 and -60.4% for total tissue, -60.6 and -62.4% for total lipids, -60.2 and-63.9% for phospholipid fatty acids, and -71.8 and 73.8% for sterols . These stable carbon isotope values revealed that the relative fractionation pattern was similar to the patterns obtained in pure culture experiments with methanotrophic bacteria (R.E . Summons, L.L . Jahnke, and Z . Roksandic, Geochim . Cosmochim . Acta 58: 2853-2863, 1994) further supporting the conversion of the bacteria methylsterol pool. Orig Life Evol Biosph, 1995 Jun, 25(1-3), 99 - 110 Evolution of the biosynthesis of the branched-chain amino acids; Keefe AD et al.; The origin of the biosynthetic pathways for the branched-chain amino acids cannot be understood in terms of the backwards development of the present acetolactate pathway because it contains unstable intermediates . We propose that the first biosynthesis of the branched-chain amino acids was by the reductive carboxylation of short branched chain fatty acids giving keto acids which were then transaminated . Similar reaction sequences mediated by nonspecific enzymes would produce serine and threonine from the abundant prebiotic compounds glycolic and lactic acids . The aromatic amino acids may also have first been synthesized in this way, e.g . tryptophan from indole acetic acid . The next step would have been the biosynthesis of leucine from alpha-ketoisovaleric acid . The acetolactate pathway developed subsequently . The first version of the Krebs cycle, which was used for amino acid biosynthesis, would have been assembled by making use of the reductive carboxylation and leucine biosynthesis enzymes, and completed with the development of a single new enzyme, succinate dehydrogenase . This evolutionary scheme suggests that there may be limitations to inferring the origins of metabolism by a simple back extrapolation of current pathways. Nature, 1989 Nov 2, 342(6245), 69 - 72 Evidence for anoxygenic photosynthesis from the distribution of bacteriochlorophylls in the Black Sea; Repeta DJ et al.; The contribution of anoxygenic photosynthesis to carbon cycling in the Black Sea, the world's largest body of anoxic marine water, has been vigorously investigated and debated for over four decades . Penetration of light into the sulphide-containing deep water may result in a zone of anaerobic primary production by photosynthetic bacteria . We report here the results of analyses of photosynthetic pigments in samples of suspended particulate matter collected from two stations in the western basin of the Black Sea . Our data demonstrate high concentrations of a bacterio-chlorophyll at the chemocline, and thus the potential for anoxygenic photosynthesis as a component of primary production in the carbon cycle of the Black Sea . More than 95% of the pigments in the bacteriochlorophyll-maximum are accounted for by a series of aromatic carotenoids and bacteriochlorophylls-e, including a previously unreported geranyl ester of 4-i-butyl bacteriochlorophyll-e . The distribution of pigments is characteristic of the obligate phototrophs Chlorobium phaeobacteroides and C . phaeovibriodes . Total depth-integrated bacteriochlorophyll at one station exceeded total chlorophyll-a in the overlying oxygenated portion of the euphotic zone . We suggest that anoxygenic photosynthesis is a relatively recent phenomenon in the Black Sea initiated by shallowing of the chemocline over the past decade and development of an anoxic layer devoid of O2 and H2S. Ann N Y Acad Sci, 1987, 503, 92 - 102 Origins of the plant chloroplasts and mitochondria based on comparisons of 5S ribosomal RNAs; Delihas N et al.; In this paper, we provide macromolecular comparisons utilizing the 5S ribosomal RNA structure to suggest extant bacteria that are the likely descendants of chloroplast and mitochondria endosymbionts . The genetic stability and near universality of the 5S ribosomal gene allows for a useful means to study ancient evolutionary changes by macromolecular comparisons . The value in current and future ribosomal RNA comparisons is in fine tuning the assignment of ancestors to the organelles and in establishing extant species likely to be descendants of bacteria involved in presumed multiple endosymbiotic events. Nature, 1993 Apr 29, 362(6423), 827 - 9 A 6,000-year sedimentary molecular record of chemocline excursions in the Black Sea; Sinninghe Damste JS et al.; The Black Sea is the world's largest anoxic basin; it is also a contemporary analogue of the environment in which carbonaceous shales and petroleum source beds formed . Recently, Repeta et al . reported that anoxygenic photosynthesis may be an important component of carbon cycling in the present Black Sea, owing to a shoaling of the chemocline and consequent penetration of the photic zone by anaerobic waters in the past few decades . It has been suggested that this was due to an anthropogenic decrease in freshwater input to the Black Sea, although natural causes were not ruled out . Here we report the distributions of sequestered photosynthetic pigments in eight core samples of sediments from the Black Sea ranging in age from zero to 6,200 years before the present . Our results show that photosynthetic green sulphur bacteria (Chlorobiaceae {correction of Clorobiaceae}) have been active in the Black Sea for substantial periods of time in the past . This finding indicates that the penetration of the photic zone by anaerobic waters is not a recent phenomenon, and suggests that natural causes for shoaling of the chemocline are more likely than anthropogenic ones. J Bioenerg Biomembr, 1992 Apr, 24(2), 137 - 8 The rhodopsins: structure and function . Introduction; Lanyi JK; NASA: Nature makes use of the propensity of retinal for light-dependent double-bond isomerization in a number of systems and in a variety of ways . The common theme for light receptors based on this kind of chemistry is that (1) the retinal is bound in most cases to a small membrane protein via a protonated lysine-retinal Schiff base, (2) the absorption maximum in the visible is tuned to a suitable wavelength largely by electrostatic interaction with polar protein residues, and (3) the light-induced bond rotations and strains in the retinal set off reaction chains during which at least part of the excess free energy acquired is transferred to the protein and causes pK shifts of acidic residues and/or backbone conformational changes . The physiological consequence of the process initiated by absorption of light is either the activation of an information transfer chain (sensory and visual rhodopsins) or energy transduction which drives the electrogenic movement of ions across the membrane (ion-motive rhodopsins) . Rhodopsins with these functions occur in bacteria and in higher organisms; from an evolutionary standpoint they are not related to one another . Nevertheless, all of these proteins are remarkably similar and form a distinct family . NASA Edited Nature, 1990 Jan 18, 343(6255), 254 - 6 Evidence from carbon isotope measurements for diverse origins of sedimentary hydrocarbons; Freeman KH et al.; The organic matter found in sedimentary rocks must derive from many sources; not only from ancient primary producers but also from consumers and secondary producers . In all of these organisms, isotope effects can affect the abundance and distribution of 13C in metabolites . Here, by using an improved form of a previously described technique in which the effluent of a gas chromatograph is continuously analysed isotopically, we report evidence of the diverse origins of sedimentary organic matter . The record of 13C abundances in sedimentary carbonate and total organic carbon can be interpreted in terms of variations in the global carbon cycle . Our results demonstrate, however, that isotope variations within sedimentary organic mixtures substantially exceed those observed between samples of total organic carbon . Resolution of isotope variations at the molecular level offers a new and convenient means of refining views both of localized palaeoenvironments and of control mechanisms within the global carbon cycle. Bioessays, 2001 Sep, 23(9), 848 - 55 Gleanings of a chemiosmotic eye; Harold FM; In 1961, an inventive Englishman, named Peter Mitchell, proposed a radically novel hypothesis to explain how energy is conserved during respiration and photosynthesis, and applied to the generation of ATP and other kinds of functional work . The chemiosmotic hypothesis sparked an intense controversy that lasted for 15 years . Today, Mitchell's conception of proton currents and their role in phosphorylation and active transport is generally accepted, and has ramified into many corners of cellular physiology . His most profound contribution may have been to introduce spatial direction into biochemistry, and thereby transform our perception of the relationship between molecules and cells . Eur J Immunol, 2001 Sep, 31(9), 2690 - 701 N-linked carbohydrates in tyrosinase are required for its recognition by human MHC class II-restricted CD4(+) T cells; Housseau F et al.; Glycosylation of mammalian proteins is known to influence their intracellular trafficking, half life, and susceptibility to enzymatic degradation . Rare instances of natural T cell epitopes dependent upon glycosylation for recognition have been described . We report here on human CD4(+) T lymphocyte cultures and clones from two melanoma patients that recognize the melanoma-associated Ag tyrosinase in the context of HLA-DR4 and -DR8 . These T cells recognize tyrosinase, normally a heavily glycosylated molecule, when expressed constitutively in melanoma cells or in COS-7 transfectants pulsed as lysates onto autologous APC . However, these T cells fail to recognize tyrosinase expressed in bacteria, nor do they react with overlapping peptides covering full-length tyrosinase, suggesting a critical role for glycosylation in the processing and / or composition of the stimulatory epitopes . The requirement for glycosylation was demonstrated by the failure of tyrosinase-specific CD4(+) T cells to recognize tyrosinase synthesized in the presence of glycosylation inhibitors, or deglycosylated enzymatically . Site-directed mutagenesis of each of seven potential N-glycosylation sites showed that four sites were required to generate forms of tyrosinase that could be recognized by individual T cell clones . These data indicate that certain carbohydrate moieties are required for processing the tyrosinase peptides recognized by CD4(+) T cells . Post-translational modifications of human tumor-associated proteins such as tyrosinase could be a critical factor for the development of antitumor immune responses. Proc Natl Acad Sci U S A, 2001 Sep 11, 98(19), 10658 - 63 Epub 2001 Sep 04. Compaction of single DNA molecules induced by binding of integration host factor (IHF); Ali BM et al.; We studied the interaction between the integration host factor (IHF), a major nucleoid-associated protein in bacteria, and single DNA molecules . Force-extension measurements of lambda DNA and an analysis of the Brownian motion of small beads tethered to a surface by single short DNA molecules, in equilibrium with an IHF solution, indicate that: (i) the DNA-IHF complex retains a random, although more compact, coiled configuration for zero or small values of the tension, (ii) IHF induces DNA compaction by binding to multiple DNA sites with low specificity, and (iii) with increasing tension on the DNA, the elastic properties of bare DNA are recovered . This behavior is consistent with the predictions of a statistical mechanical model describing how proteins bending DNA are driven off by an applied tension on the DNA molecule . Estimates of the amount of bound IHF in DNA-IHF complexes obtained from the model agree very well with independent measurements of this quantity obtained from the analysis of DNA-IHF crosslinking . Our findings support the long-held view that IHF and other histone-like proteins play an important role in shaping the long-scale structure of the bacterial nucleoid. J Ethnopharmacol, 2001 Oct, 77(2-3), 247 - 52 The effects of storage on the biological activity of medicinal plants from Nepal; Griggs JK et al.; The in vitro biological activity of 19 medicinal plants from Nepal was re-assessed after 6 years of storage . Methanol extracts from the plants were assayed for activity against six strains of bacteria and three strains of fungi . The extracts were tested with and without exposure to UV light in order to identify photoactivity . Out of the 19 plants tested, three lost all activity, six retained all activity, and ten had partial activity . The results will be of interest to traditional healers in Nepal, and may impact the sustainable harvesting of these medicinal plants. Plasmid, 2001 Jul, 46(1), 10 - 5 ISMh2, a novel insertion sequence-like element associated with nifA from Mesorhizobium huakuii; Gao C et al.; Sequence analysis of the nifA gene, including its 5' flanking region, of Mesorhizobium huakuii revealed the presence of a novel IS-like element called ISMh2 . It is 828 bp in length and possesses two imperfect terminal inverted repeats of 14 bp with only one mismatch . The putative transposase encoded by ISMh2 is composed of 204 amino acids . In comparison with other insertion sequences ISMh2 likely belongs to the IS6 family . Multiple copies of ISMh2 were detected in the genome of M . huakuii 159 by Southern hybridization . RT-PCR analysis showed that nifA and ISMh2 cotranscribed . Attempts to detect the transposition ability of ISMh2 were unsuccessful . Scanning, 2001 Jul-Aug, 23(4), 267 - 72 Manipulating biological samples for environmental scanning electron microscopy observation; Tai SS et al.; Biological samples having different characteristics were observed by environmental scanning electron microscopy (ESEM) . The environmental conditions for untreated biological samples was determined by optimizing sample temperature and chamber pressure . When the temperature was at 4 degrees - 6 degrees C and chamber pressure was 5.2-5.9 Torr, the relative humidity in the specimen chamber was about 85% . Under these conditions, the surface features of the sample were completely exposed and did not exhibit charging . The images obtained from the untreated samples at different ESEM conditions were also compared with fixed and coated samples observed under high vacuum. J Parasitol, 2001 Aug, 87(4), 877 - 89 Phylogeny of Steinernema travassos, 1927 (Cephalobina: Steinernematidae) inferred from ribosomal DNA sequences and morphological characters; Stock SP et al.; Entomopathogenic nematodes in Steinernema, together with their symbiont bacteria Xenorhabdus, are obligate and lethal parasites of insects that can provide effective biological control of some important lepidopteran, dipteran, and coleopteran pests of commercial crops . Phylogenetic relationships among 21 Steinernema species were estimated using 28S ribosomal DNA (rDNA) sequences and morphological characters . Sequences of the rDNA internal transcribed spacers were obtained to provide additional molecular characters to resolve relationships among Steinernema carpocapsae, Steinernema scapterisci, Steinernema siamkavai, and Steinernema monticolum . Four equally parsimonious trees resulted from combined analysis of 28S sequences and 22 morphological characters . Clades inferred from analyses of molecular sequences and combined datasets were primarily reliably supported as assessed by bootstrap resampling, whereas those inferred from morphological data alone were not . Although partially consistent with some traditional expectations and previous phylogenetic studies, the hypotheses inferred from molecular evidence, and those from combined analysis of morphological and molecular data, provide a new and comprehensive framework for evaluating character evolution of steinernematids . Interpretation of morphological character evolution on 6 trees inferred from sequence data and combined evidence suggests that many structural features of these nematodes are highly homoplastic, and that some structures previously used to hypothesize relationships represent ancestral character states. Pharmazie, 2001 Aug, 56(8), 654 - 6 Post-irradiation effect of Broncho-Vaxom, OM-85 BV, and its relationship to anti-oxidant activities; Saada HN et al.; This study was conducted to test the efficacy of Broncho-Vaxom (OM-85 BV) in rats after exposure to radiation-induced oxidative stress . Daily administration of Broncho-Vaxom (2.5 mg/kg/day) to rats for a period of 28 days produced a progressive significant increase in the activities of superoxide dismutase (SOD) and catalase in lungs and erythrocytes . No changes were recorded in reduced glutathione (GSH) content in lungs, while an increase was recorded in erythrocytes . Significant increase was also observed in serum gamma-globulin content . Intraperitoneal administration of Broncho-Vaxom to rats for 11 days before gamma-irradiation and daily during the period of irradiation, delivered as 1 Gy every other day to reach 9 Gy, significantly reduced radiation-induced lipid peroxidation (LPO) measured as thiobarbituric acid-reactive substances (TBARS) in the lungs and erythrocytes . Treatment with Broncho-Vaxom modified the radiation-induced decrease of serum gamma-globulins contents . It is postulated that Broncho-Vaxom, by enhancing the antioxidant system and increasing serum gamma-globulin content, could play an important role in modifying radiation-induced oxidative stress. Rheum Dis Clin North Am, 2001 Aug, 27(3), 551 - 63 Origin of antiphospholipid antibodies; Gharavi AE et al.; Our observations and those from others give further support to our hypothesis that "autoimmune aPL" may be generated by immunization with products from bacteria or viruses after incidental exposure or infection . We also were able to generate an APS-like syndrome in a strain of mice susceptible to autoimmunity, indicating that other factors such as genetic factors are likely to be involved in development of APS . Furthermore, not all aPL generated by immunization with bacterial or viral products were pathogenic . Based on the clinical experience and on the numerous reports indicating the presence of aPL in large number of infectious diseases, it may be expected that not all aPL produced during infection are pathogenic . We hypothesize that a limited number aPL induced by certain viral or bacterial products would be pathogenic in certain groups of predisposed individuals . Identification of those bacterial or viral agents may help to find strategies for the prevention of production of "pathogenic" aPL . Alternatively, free peptides may be used to induce tolerance against aPL production. Nat Rev Genet, 2001 Sep, 2(9), 702 - 15 Time zones: a comparative genetics of circadian clocks; Young MW et al.; The circadian clock is a widespread cellular mechanism that underlies diverse rhythmic functions in organisms from bacteria and fungi, to plants and animals . Intense genetic analysis during recent years has uncovered many of the components and molecular mechanisms comprising these clocks . Although autoregulatory genetic networks are a consistent feature in the design of all clocks, the weight of evidence favours their independent evolutionary origins in different kingdoms. Nat Cell Biol, 2001 Sep, 3(9), 852 - 5 Four-dimensional imaging and quantitative reconstruction to analyse complex spatiotemporal processes in live cells; Gerlich D et al.; Live-cell imaging technology using fluorescent proteins (green fluorescent protein and its homologues) has revolutionized the study of cellular dynamics . But tools that can quantitatively analyse complex spatiotemporal processes in live cells remain lacking . Here we describe a new technique--fast multi-colour four-dimensional imaging combined with automated and quantitative time-space reconstruction--to fill this gap . As a proof of principle, we apply this method to study the re-formation of the nuclear envelope in live cells . Four-dimensional imaging of three spectrally distinct fluorescent proteins is used to simultaneously visualize three different cellular compartments at high speed and with high spatial resolution . The highly complex data, comprising several thousand images from a single cell, were quantitatively reconstructed in time-space by software developed in-house . This analysis reveals quantitative and qualitative insights into the highly ordered topology of nuclear envelope formation, in correlation with chromatin expansion - results that would have been impossible to achieve by manual inspection alone . Our new technique will greatly facilitate study of the highly ordered dynamic architecture of eukaryotic cells. J Antimicrob Chemother, 2001 Sep, 48(3), 431 - 4 Airways delivery of rifampicin microparticles for the treatment of tuberculosis; Suarez S et al.; A Mycobacterium tuberculosis (H37Rv)-infected guinea pig model was used to screen for targeted delivery to the lungs by insufflation (with lactose excipient) or nebulization, of either rifampicin alone, rifampicin within poly(lactide-co-glycolide) microspheres (R-PLGA) or polymer microparticles alone (PLGA) . Animals treated with single and double doses of R-PLGA microspheres exhibited significantly reduced numbers of viable bacteria, inflammation and lung damage compared with lactose-, PLGA- or rifampicin-treated animals 28 days post-infection (P < 0.05) . Two doses of R-PLGA resulted in reduced splenic enlargement . These studies support the potential of R-PLGA delivered to the lung to treat pulmonary tuberculosis. EMBO J, 2001 Sep 3, 20(17), 4964 - 72 Structure of the ABC ATPase domain of human TAP1, the transporter associated with antigen processing; Gaudet R et al.; The transporter associated with antigen processing (TAP) is an ABC transporter formed of two subunits, TAP1 and TAP2, each of which has an N-terminal membrane-spanning domain and a C-terminal ABC ATPase domain . We report the structure of the C-terminal ABC ATPase domain of TAP1 (cTAP1) bound to ADP . cTAP1 forms an L-shaped molecule with two domains, a RecA-like domain and a small alpha-helical domain . The diphosphate group of ADP interacts with the P-loop as expected . Residues thought to be involved in gamma-phosphate binding and hydrolysis show flexibility in the ADP-bound state as evidenced by their high B-factors . Comparisons of cTAP1 with other ABC ATPases from the ABC transporter family as well as ABC ATPases involved in DNA maintenance and repair reveal key regions and residues specific to each family . Three ATPase subfamilies are identified which have distinct adenosine recognition motifs, as well as distinct subdomains that may be specific to the different functions of each subfamily . Differences between TAP1 and TAP2 in the nucleotide-binding site may be related to the observed asymmetry during peptide transport. EMBO J, 2001 Sep 3, 20(17), 4952 - 63 A moving DNA replication factory in Caulobacter crescentus; Jensen RB et al.; The in vivo intracellular location of components of the Caulobacter replication apparatus was visualized during the cell cycle . Replisome assembly occurs at the chromosomal origin located at the stalked cell pole, coincident with the initiation of DNA replication . The replisome gradually moves to midcell as DNA replication proceeds and disassembles upon completion of DNA replication . Although the newly replicated origin regions of the chromosome are rapidly moved to opposite cell poles by an active process, the replisome appears to be an untethered replication factory that is passively displaced towards the center of the cell by the newly replicated DNA . These results are consistent with a model in which unreplicated DNA is pulled into the replication factory and newly replicated DNA is bidirectionally extruded from the complex, perhaps contributing to chromosome segregation. Front Biosci, 2001 Sep 01, 6, D1109 - 27 The human mast cell: functions in physiology and disease; Krishnaswamy G et al.; Mast cells are multifunctional, tissue-dwelling cells capable of secreting a wide variety of mediators . They develop from bone marrow-derived progenitor cells, primed with stem cell factor (SCF), which mediates its actions by interacting with the SCF receptor or c-kit on the cell surface . Mast cells continue their maturation and differentiation in peripheral tissue, developing into two well described subsets of cells, MCT and MCTC cells, varying in content of tryptase and chymase as well as in immunobiology . Mast cells are activated by numerous stimuli, including antigen (acting via the high affinity IgE receptor, Fc?RI), superoxides, complement proteins, neuropeptides and lipoproteins resulting in activation and degranulation . Following activation, these cells express mediators such as histamine, leukotrienes and prostanoids, as well as proteases, and many cytokines and chemokines, pivotal to the genesis of an inflammatory response . Recent data suggests that mast cells may play an active role in such diverse diseases as atherosclerosis, malignancy, asthma, pulmonary fibrosis and arthritis . Mast cells directly interact with bacteria and appear to play a vital role in host defense against pathogens . Drugs, such as glucocorticoids, cyclosporine and cromolyn have been demonstrated to have inhibitory effects on mast cell degranulation or mediator release. Fertil Steril, 2001 Sep, 76(3), 496 - 500 The concentration of nitrite in seminal plasma does not correlate with sperm concentration, sperm motility, leukocytospermia, or sperm culture; Revelli A et al.; OBJECTIVE: To correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with sperm number and motility, leukocytospermia, and sperm culture . DESIGN: Prospective study . SETTING: Academic research institution . PATIENT(S): Seventy normozoospermic or dyspermic men enrolled in an artificial insemination/in vitro fertilization program . INTERVENTION(S): Semen samples (n = 70) were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration, and sperm culture; similarly, the concentration of nitrite in seminal plasma was measured by Griess reaction . MAIN OUTCOME MEASURE(S): Measurement of nitrite concentration in seminal plasma and its correlation with sperm concentration, total sperm count, sperm motility, leukocytospermia, and sperm culture . RESULT(S): The concentration of nitrite in seminal plasma does not correlate with sperm concentration, total sperm count, or with the proportion of immotile or rapid-forward motile spermatozoa . Moreover, the concentration of nitrite in seminal plasma is not significantly increased when sperm culture is positive, nor does it correlate with leukocyte concentration in semen . CONCLUSION(S): Our results do not support the hypothesis that in vivo nitric oxide synthesis affects sperm function; alternatively, our results could suggest that nitrite in the seminal plasma is not a sensitive marker of in vivo nitric oxide synthesis. FEBS Lett, 2001 Aug 31, 504(3), 126 - 32 Insights from the structure of the yeast cytochrome bc1 complex: crystallization of membrane proteins with antibody fragments; Hunte C; The ubiquinol:cytochrome c oxidoreductase (EC 1.20.2.2, QCR or cytochrome bc1 complex) is a component of respiratory and photosynthetic electron transfer chains in mitochondria and bacteria . The complex transfers electrons from quinol to cytochrome c . Electron transfer is coupled to proton translocation across the lipid bilayer, thereby generating an electrochemical proton gradient, which conserves the free energy of the redox reaction . The yeast complex was crystallized with antibody Fv fragments, a promising technique to obtain well-ordered crystals from membrane proteins . The high-resolution structure of the yeast protein reveals details of the catalytic sites of the complex, which are important for electron and proton transfer. FEBS Lett, 2001 Aug 31, 504(3), 94 - 8 Overexpression of mammalian integral membrane proteins for structural studies; Tate CG; Recent successes in the determination of atomic resolution structures of integral membrane proteins have relied on purifying the proteins from abundant natural sources . In contrast, the majority of mammalian receptors, ion channels and transporters need to be overexpressed to obtain sufficient material for structural studies . This has often proved to be very difficult . Overexpression studies on a wide range of mammalian membrane proteins have shown that a few can be expressed functionally in bacteria, but many others require an insect or mammalian cell host for activity or high level expression . The serotonin transporter, which has been expressed in all the major hosts available, is a good example that has given insights into the problem of overexpressing mammalian membrane proteins for structural studies. Mol Immunol, 2001 Aug, 38(2-3), 133 - 49 The mannan-binding lectin pathway of complement activation: biology and disease association; Petersen SV et al.; Mannan-binding lectin (MBL) is a plasma protein found in association with several serine proteases (MASPs) forming the MBL complex . MBL recognises carbohydrate structures arranged in a particular geometry, such as those found on the surface of micro-organisms . When bound to e.g . bacteria the MBL complex will initiate the activation of the complement cascade . Mounting evidence supports the importance of the MBL pathway of complement activation in innate immunity . In this review, we focus on the structure and function of the proteins within the MBL pathway and address the properties of the pathway as an initiator of the host response against potential pathogenic micro-organisms. BMC Geriatr . 2001;1(1):1. Identifying research priorities on infections in older adults: proceedings of an interdisciplinary workshop; Loeb M et al.; BACKGROUND: Infections pose a substantial burden to the health of older adults . In this report, we describe the proceedings of a workshop to formulate and prioritize research questions about infections in older adults using an interdisciplinary approach . METHODS: Researchers from four sectors (basic science, clinical sciences, health services and epidemiology/determinants of health) and representatives from various Canadian local, provincial, and federal stakeholder groups were invited to a two-day workshop . Five multi-disciplinary groups and stakeholders from each of three healthcare settings (long term, acute care and community) discussed research priorities for each of the settings . Five to ten research questions were identified for each setting . RESULTS: The research questions proposed ranged from risk factors and outcomes for different infections to the effect of nutrition on infection and the role of alternative and complementary medicine in treating infections . Health service issues included barriers to immunization, prolongation of hospital length of stay by infection, use of care paths for managing infections, and decision-making in determining the site of care for individuals with infections . Clinical questions included risk factor assessment for infection, the effectiveness of preventative strategies, and technology evaluation . Epidemiologic issues included the challenge of achieving a better understanding of respiratory infections in the community and determining the prevalence of colonization with multi-resistant bacteria . CONCLUSIONS: The questions are of direct relevance to researchers in a wide variety of fields . Bringing together a multi-disciplinary group of researchers to frame and prioritize research questions about aging is feasible, participants valued the opinions of people working in other areas. Eur J Biochem, 2001 Sep, 268(17), 4720 - 30 Phytochrome Cph1 from the cyanobacterium Synechocystis PCC6803 . Purification, assembly, and quaternary structure; Lamparter T et al.; The phytochrome Cph1 from the cyanobacterium Synechocystis PCC6803 forms holoprotein adducts with close spectral similarity to plant phytochromes when autoassembled in vitro with bilin chromophores . Cph1 is a 85-kDa protein that acts as a light-regulated histidine kinase seemingly involved in 'two-component' signalling . This paper describes the improvement of Cph1 purification, estimation of the extinction coefficient of holo-Cph1, spectral analyses of the assembly procedure and studies on quaternary structure . During assembly with the natural chromophore phycocyanobilin (PCB), a red-shifted intermediate is observed . A similar result was obtained when phycoerythrobilin was used as chromophore . As shown by SDS/PAGE and Zn2+ fluorescence, the covalent attachment of PCB is blocked by 1 mM iodoacetamide, a cysteine-derivatizing agent . When PCB was incubated with blocked apo-Cph1, again a shoulder at longer wavelengths appeared . It is therefore proposed that the long-wavelength-absorbing form represents the protonated, noncovalently bound bilin . Biliverdin, which is neither protonated nor covalently attached, undergoes spectral changes in its blue-absorbing band upon incubation with apo-Cph1 . On the basis of these data we therefore propose a three-step model for phytochrome autoassembly . Size-exclusion chromatography revealed different mobilities for the apoprotein, red-absorbing Cph1-PCB and far-red-absorbing Cph1-PCB . The major peaks of both holoprotein adducts had apparent molecular masses approximately 200 kDa, a result in agreement with the notion that autophosphorylation in sensory histidine kinases requires dimerization . When Cph1-PCB was further purified by preparative native electrophoresis, the mobility on size-exclusion chromatography was approximately 100 kDa, and it was found to have lost its kinase activity, results implying that the material had lost its capacity to dimerize. Clin Microbiol Infect, 2001 Jul, 7(7), 369 - 72 Brucella detection in blood: comparison of the BacT/Alert standard aerobic bottle, BacT/Alert FAN aerobic bottle and BacT/Alert enhanced FAN aerobic bottle in simulated blood culture; Sumerkan B et al.; The objective of this study was to compare the performances of the standard aerobic bottle (StAe), FAN aerobic (FANAe) and enhanced FAN aerobic (E-FANAe) (the charcoal component of the FANAe was revised recently to improve the feasibility of Gram smear interpretation) blood culture bottles for BacT/Alert system for the detection of Brucella melitensis in simulated blood culture . Triplicate strains of eight clinical isolates of B . melitensis were studied . Each bottle was inoculated with 5 mL of freshly collected human blood at three different targeted bacterial inocula (10(1), 10(2) and 10(3) CFU/bottle) . All bottles were monitored for up to 21 days or until they became positive . The results of time to detection (TTD) on the eight B . melitensis samples were as follows: at 10(1) CFU/bottle, the E-FANAe had a mean TTD significantly shorter than the StAe (48 h vs . 56.2 h, P < 0.05); and at 10(3) CFU/bottle, the FANAe and E-FANAe had a mean TTD significantly shorter than the StAe (41.2 h and 40 h vs . 45.6 h, P < 0.05) . The reproducibilities (no.of positive signals/no.of all bottles) of three bottle systems were as follows: at 10(1) CFU/bottle, the reproducibilities of StAe, FANAe and E-FANAe were 96, 83 and 58%, respectively . At 10(3) CFU/bottle, the reproducibilities of StAe, FANAe and E-FANAe were 95, 95 and 91%, respectively . Positive results for the presence of bacteria in Gram smears were confirmed in 68% of StAe, 54% of FANAe and 90% of E-FANAe . In case of suspected brucellosis, the combination of one StAe bottle and one E-FANAe bottle seems to provide the highest and fastest recovery of the organism. Z Naturforsch {C}, 2001 Jul-Aug, 56(7-8), 581 - 4 Bradyrhizobium japonicum mutants defective in cyclic beta-glucan synthesis show enhanced sensitivity to plant defense responses; Mithofer A et al.; Susceptibility of the nitrogen-fixing soybean symbiont Bradyrhizobium japonicum to inducible plant defense metabolites such as phytoalexin and H2O2, was investigated . On the wild-type strain USDA 110 the soybean phytoalexin, glyceollin, showed bacteriostatic activity . Viable bacteria isolated from intact nodules were adapted to glyceollin . H2O2 in physiological concentrations did not affect wild-type bacteria . B . japonicum mutants defective in the biosynthesis of cyclic beta-(1-->3)-(1-->6)-glucans showed higher susceptibility to both phytoalexin and H2O2. Waste Manag, 2001, 21(7), 643 - 50 Anaerobic biotransformation and methane generation potential of cheese whey in batch and UASB reactors; Erguder TH et al.; Anaerobic treatability and methane generation potential of cheese whey were determined in batch reactors . Furthermore, the effect of nutrient and trace metal supplementation on the batch anaerobic treatment, and the high-rate anaerobic treatability of cheese whey in upflow anaerobic sludge blanket (UASB) reactors were investigated . To this purpose biochemical methane potential experiments were conducted and single- and two-stage UASB reactors with granular cultures were operated . In UASB experiments significance of process staging, operational parameters such as hydraulic retention time (HRT), influent chemical oxygen demand (COD) concentration and loading rate were also investigated . The results revealed that nutrient and trace metal supplementation is vital for the anaerobic treatment of cheese whey; the anaerobic methane generation for the cheese whey studied was found to be 424 ml CH4/g COD (23.4 1 CH4/l cheese whey); undiluted cheese whey could be treated anaerobically at relatively short HRT values (2.06-4.95 days) without any significant stability problems; HRT values as low as 2-3 days can be used for the anaerobic treatment of cheese whey, with a COD removal efficiency of 95-97% at influent COD concentration of 42 700 +/- 141-55 100 +/- 283 mg/l. Waste Manag, 2001, 21(7), 617 - 29 Perpetual landfilling through aeration of the waste mass; lessons from test cells in Georgia (USA); Read AD et al.; Municipal solid waste (MSW) landfills worldwide are experiencing the consequences of conventional landfilling techniques, whereby anaerobic conditions are created within the landfilled waste . Under anaerobic conditions within a landfill site slow stabilization of the waste mass occurs, producing methane, (an explosive 'green house' gas) and leachate (which can pollute groundwater) over long periods of time . As a potential solution, it was demonstrated that the aerobic degradation of MSW within a landfill can significantly increase the rate of waste decomposition and settlement, decrease the methane production and leachate leaving the system, and potentially increase the operational life of the site . Readily integrated into the existing landfill infrastructure, this approach can safely and cost-effectively convert a MSW landfill from anaerobic to aerobic degradation processes, thereby effectively composting much of the organic portions (one of the potentially polluting elements in a conventional landfill site) of the waste . This paper summarizes the successful results of two separate aerobic landfill projects located in Georgia (USA) and discusses the potential economic and environmental impacts to worldwide solid waste management practices. Immunology, 2001 Aug, 103(4), 511 - 8 Interferon-gamma is crucial for surviving a Brucella abortus infection in both resistant C57BL/6 and susceptible BALB/c mice; Murphy EA et al.; Brucella abortus is an intracellular bacterial pathogen that causes chronic infections in humans and a number of agriculturally important species of animals . It has been shown that BALB/c mice are more susceptible to infections with virulent strains of Brucella abortus than C57BL/6 or C57BL/10 strains . In experiments described here, gene knock-out mice were utilized to elucidate some of the salient components of resistance . Resistant C57BL/6 mice with gene deletions or disruptions in the interferon-gamma (IFN-gamma), perforin or beta(2)-microglobulin genes had decreased abilities to control intracellular infections with B . abortus strain 2308 during the first week after infection . However, only the IFN-gamma knock-out mice had a sustained inability to control infections and this resulted in death of the mice at approximately 6 weeks post-infection . These mice had a continual increase in the number of bacterial colony-forming units (CFU) in their spleens until death . When BALB/c mice with the disrupted IFN-gamma gene were infected they had more splenic CFU at one week post-infection than control mice but the increase was not statistically significant and by 3 weeks they did not have more CFU than control mice . Moreover, the number of splenic bacteria did not increase in the BALB/c IFN-gamma knock-out mice between 6 and 10.5 weeks, although they died at 10.5 weeks, the time by which normal BALB/c mice were clearing the infection . Death in both strains of IFN-gamma gene disrupted mice coincided with symptoms of cachexia and macrophages comprised > or= 75% of the splenic leucocytes. Microbiol Immunol, 2001, 45(7), 539 - 41 Fate of Legionella pneumophila in macrophages of C57BL/6 chronic granulomatous disease mice; Saito M et al.; We compared the intracellular survival and growth of Legionella pneumophila Philadelphia-1 in peritoneal macrophages obtained from A/J, C57BL/6, and X-linked chronic granulomatous disease (CGD) mice produced from C57BL/6 strain . The initial killing was observed in A/J and C57BL/6 macrophages at 2, 4 and 6 hr after in vitro phagocytosis, but not in the CGD macrophages . Thereafter, there was a 10-fold increase of CFU in A/J macrophages . The bacteria, however, did not proliferate in C57BL/6 and CGD macrophages at 24 or 48 hr after in vitro phagocytosis . These results suggest that effector molecules for the initial killing are a superoxide anion and its metabolites, and Lgn1 gene product inhibits the intracellular growth of L . pneumophila independently of NADPH oxidase. J Med Assoc Thai, 2001 Jun, 84 Suppl 1, S32 - 8 Current management of Helicobacter pylori infection; Vilaichone RK et al.; Helicobacter pylori is commonly found throughout the world . It is associated with a wide range of gastroduodenal diseases . Knowledge regarding the characteristic organism, behaviour, and related clinical conditions is extensive . Indeed, the bacteria is not the only factor which can cause the diseases, the host as well as environmental factors are also important . Largely, H . pylori is disappearing worldwide due to eradication of this organism allowing frequency of an H . pylori negative ulcer to relatively increase and may be more difficult to treat . The PPI triple therapy remains the first line of treatment with quadruple therapy as the second rescue line . The rising of bacterial resistant strains is a new problem which requires new drugs to improve the efficacy of the current regimens. J Med Assoc Thai, 2001 Jun, 84 Suppl 1, S127 - 30 Primary conjunctival tuberculoma: a case report; Tulvatana W et al.; Conjunctival tuberculoma is very rare in modern medicine . We report a case of a 34-year-old Thai female patient presenting with multiple peculiar conjunctival nodules . Two small nodules were excised and submitted for histopathological study, which showed discrete granulomatous inflammation with caseating necrosis . The acid-fast bacilli's staining for tuberculous bacteria was positive . There was no other organ involvement of active tuberculosis . The patient was then treated with systemic anti-tuberculous regimen for 6 months . The remaining lesions disappeared within the first few months of treatment . Conjunctival tuberculoma should always be considered in cases of conjunctival nodules. J Infect Dis, 2001 Oct 1, 184(7), 879 - 84 Epub 2001 Aug 22. Epidemiology and clinical manifestations of unique Chlamydia trachomatis isolates that occupy nonfusogenic inclusions; Geisler WM et al.; Unique Chlamydia trachomatis strains characterized by multiple nonfusing inclusions were recently described . These strains lack evidence of the protein IncA in the inclusion membrane and have mutations in the incA gene . This study evaluated the epidemiology and clinical manifestations of patients infected with nonfusing mutant strains (case patients) and compared them with patients infected with wild-type fusing strains (control subjects) . Both male and female case patients had fewer signs of infection than did control subjects (P=.016 and P=.019, respectively) . Female case patients also had fewer symptoms of infection (P=.02) . Median inclusion-forming unit (ifu) counts were lower in male and female case patients (P=.045 and P=.135, respectively) . Thus, nonfusing strains of C . trachomatis more often produce subclinical infections than do normal fusing strains and have lower median ifu counts . From a prevention perspective, the data underscore the importance of screening programs to detect and treat inapparent C . trachomatis infection. Clin Diagn Lab Immunol, 2001 Sep, 8(5), 980 - 3 Late hematogenous infection of subcutaneous implants in rats; Gottenbos B et al.; Late biomaterial-centered infection is a major complication associated with the use of biomaterial implants . In this study biomaterials that had been implanted subcutaneously in rats were hematogenously challenged with bacteria 4 weeks after implantation . Bacteria were spread either by intravenous injection or by stimulation of bacterial translocation . It was found that none of the biomaterials was infected by hematogenous spread, whereas 5% of the implants were infected by perioperative contamination . We conclude that late hematogenous infection of subcutaneous biomaterials does not occur in the rat . For humans as well, there are growing doubts whether implants actually become infected through hematogenous routes; it is thought that late infections may be caused by delayed appearance of perioperatively introduced bacteria. J Clin Microbiol, 2001 Sep, 39(9), 3072 - 9 PCR detection and molecular identification of Chlamydiaceae species; Hartley JC et al.; Recent taxonomic developments, based on 16s and 23s rRNA gene sequences, have divided the family Chlamydiaceae into two genera and nine species, of which five have been found to infect humans . Few simple methods are available to detect and identify all species sensitively and specifically . In this study the suitability of the omp2 gene as a target for molecular identification of Chlamydiaceae is demonstrated . Phylogenetic analysis of partial omp2 gene sequences from all nine species agrees with the recently published taxonomic changes based on the ribosomal genes . The use of a family-specific PCR primer pair, which is able to amplify the 5' end of the omp2 gene from all Chlamydiaceae except some Chlamydophila pecorum strains, is described . Identification of all nine species was achieved using restriction fragment length polymorphism analysis with a single enzyme, AluI, confirmed by DNA sequencing . A PCR enzyme-linked oligonucleotide assay was developed which can detect a single chlamydial genome and may be applied to DNA extracts from any specimen or culture for the detection of single or mixed human chlamydial infection. Biol Bull, 2001 Aug, 201(1), 65 - 75 Molecular evidence that Sclerolinum brattstromi is closely related to vestimentiferans, not to frenulate pogonophorans (Siboglinidae, Annelida); Halanych KM et al.; Siboglinids, previously referred to as pogonophorans, have typically been divided into two groups, frenulates and vestimentiferans . Adults of these marine protostome worms lack a functional gut and harbor endosymbiotic bacteria . Frenulates usually live in deep, sedimented reducing environments, and vestimentiferans inhabit hydrothermal vents and sulfide-rich hydrocarbon seeps . Taxonomic literature has often treated frenulates and vestimentiferans as sister taxa . Sclerolinum has traditionally been thought to be a basal siboglinid that was originally regarded as a frenulate and later as a third lineage of siboglinids, Monilifera . Evidence from the 18S nuclear rDNA gene and the 16S mitochondrial rDNA gene presented here shows that Sclerolinum is the sister clade to vestimentiferans although it lacks the characteristic morphology (i.e., a vestimentum) . The rDNA data confirm the contention that Sclerolinum is different from frenulates, and further supports the idea that siboglinid evolution has been driven by a trend toward increased habitat specialization . The evidence now available indicates that vestimentiferans lack the molecular diversity expected of a group that has been argued to have Silurian or possibly Cambrian origins. Appl Environ Microbiol, 2001 Sep, 67(9), 4353 - 7 Anaerobic mineralization of stable-isotope-labeled 2-methylnaphthalene; Sullivan ER et al.; An active sulfate-reducing consortium that degrades 2-methylnaphthalene (2-MNAP) at rates of up to 25 microM x day(-1) was established . Degradation was inhibited in the presence of molybdate and ceased in the absence of sulfate . As much as 87% of 2-{14C}MNAP was mineralized to 14CO2 . 2-Naphthoic acid (2-NA) was detected as a metabolite, and incubation with either deuterated 2-MNAP or {13C}bicarbonate indicates that 2-NA is the result of oxidation of the methyl group . Also detected were carboxylated 2-MNAPs, suggesting the presence of an alternative pathway for 2-MNAP degradation. Appl Environ Microbiol, 2001 Sep, 67(9), 4177 - 85 Detection of methanotroph diversity on roots of submerged rice plants by molecular retrieval of pmoA, mmoX, mxaF, and 16S rRNA and ribosomal DNA, including pmoA-based terminal restriction fragment length polymorphism profiling; Horz HP et al.; The diversity of methanotrophic bacteria associated with roots of submerged rice plants was assessed using cultivation-independent techniques . The research focused mainly on the retrieval of pmoA, which encodes the alpha subunit of the particulate methane monooxygenase . A novel methanotroph-specific community-profiling method was established using the terminal restriction fragment length polymorphism (T-RFLP) technique . The T-RFLP profiles clearly revealed a more complex root-associated methanotrophic community than did banding patterns obtained by pmoA-based denaturing gradient gel electrophoresis . The comparison of pmoA-based T-RFLP profiles obtained from rice roots and bulk soil of flooded rice microcosms suggested that there was a substantially higher abundance of type I methanotrophs on rice roots than in the bulk soil . These were affiliated to the genera Methylomonas, Methylobacter, Methylococcus, and to a novel type I methanotroph sublineage . By contrast, type II methanotrophs of the Methylocystis-Methylosinus group could be detected with high relative signal intensity in both soil and root compartments . Phylogenetic treeing analyses and a set of substrate-diagnostic amino acid residues provided evidence that a novel pmoA lineage was detected . This branched distinctly from all currently known methanotrophs . To examine whether the retrieval of pmoA provided a complete view of root-associated methanotroph diversity, we also assessed the diversity detectable by recovery of genes coding for subunits of soluble methane monooxygenase (mmoX) and methanol dehydrogenase (mxaF) . In addition, both 16S rRNA and 16S ribosomal DNA (rDNA) were retrieved using a PCR primer set specific to type I methanotrophs . The overall methanotroph diversity detected by recovery of mmoX, mxaF, and 16S rRNA and 16S rDNA corresponded well to the diversity detectable by retrieval of pmoA. Appl Environ Microbiol, 2001 Sep, 67(9), 4009 - 16 nifH sequences and nitrogen fixation in type I and type II methanotrophs; Auman AJ et al.; Some methane-oxidizing bacteria (methanotrophs) are known to be capable of expressing nitrogenase and utilizing N2 as a nitrogen source . However, no sequences are available for nif genes in these strains, and the known nitrogen-fixing methanotrophs are confined mainly to a few genera . The purpose of this work was to assess the nitrogen-fixing capabilities of a variety of methanotroph strains . nifH gene fragments from four type I methanotrophs and seven type II methanotrophs were PCR amplified and sequenced . Nitrogenase activity was confirmed in selected type I and type II strains by acetylene reduction . Activities ranged from 0.4 to 3.3 nmol/min/mg of protein . Sequence analysis shows that the nifH sequences from the type I and type II strains cluster with nifH sequences from other gamma proteobacteria and alpha proteobacteria, respectively . The translated nifH sequences from three Methylomonas strains show high identity (95 to 99%) to several published translated environmental nifH sequences PCR amplified from rice roots and a freshwater lake . The translated nifH sequences from the type II strains show high identity (94 to 99%) to published translated nifH sequences from a variety of environments, including rice roots, a freshwater lake, an oligotrophic ocean, and forest soil . These results provide evidence for nitrogen fixation in a broad range of methanotrophs and suggest that nitrogen-fixing methanotrophs may be widespread and important in the nitrogen cycling of many environments. Appl Environ Microbiol, 2001 Sep, 67(9), 3943 - 50 Isolation of an insertion sequence from Ralstonia solanacearum race 1 and its potential use for strain characterization and detection; Lee YA et al.; A new insertion sequence (IS), IS1405, was isolated and characterized from a Ralstonia solanacearum race 1 strain by the method of insertional inactivation of the sacB gene . Sequence analysis indicated that the IS is closely related to the members of IS5 family, but the extent of nucleotide sequence identity in 5' and 3' noncoding regions between IS1405 and other members of IS5 family is only 23 to 31% . Nucleotide sequences of these regions were used to design specific oligonucleotide primers for detection of race 1 strains by PCR . The PCR amplified a specific DNA fragment for all R . solanacearum race 1 strains tested, and no amplification was observed with some other plant-pathogenic bacteria . Analysis of nucleotide sequences flanking IS1405 and additional five endogenous IS1405s that reside in the chromosome of R . solanacearum race 1 strains indicated that IS1405 prefers a target site of CTAR and has two different insertional orientations with respect to this target site . Restriction fragment length polymorphism (RFLP) pattern analysis using IS1405 as a probe revealed extensive genetic variation among strains of R . solanacearum race 1 isolated from eight different host plants in Taiwan . The RFLP patterns were then used to subdivide the race 1 strains into two groups and several subgroups, which allowed for tracking different subgroup strains of R . solanacearum through a host plant community . Furthermore, specific insertion sites of IS1405 in certain subgroups were used as a genetic marker to develop subgroup-specific primers for detection of R . solanacearum, and thus, the subgroup strains can be easily identified through a rapid PCR assay rather than RFLP analysis. Exp Gerontol, 2001 Sep, 36(9), 1565 - 79 Really old-palaeoimmunology: immunohistochemical analysis of extracellular matrix proteins in historic and pre-historic material; Wick G et al.; In this review, we summarize data concerning the respective preservation and deterioration of antigenic determinants of various collagenous and non-collagenous extracellular matrix (ECM) proteins in palaeontologic material of different ages . ECM proteins are the major quantitative constituents of mammalian organisms and were, therefore, selected as important representative proteins for these analyses . The specimens, studied by immunofluorescence and immunohistochemical techniques, included the skin of 500-1500 year-old human mummies from Peru, skin and striated muscle from the 5300-year-old glacier mummy ("Iceman") from Tyrol, Austria, and a 50-million-year-old bat with preserved soft body parts from the fossil excavation site of Messel, Germany . In frozen sections of the former two sources, epitopes recognized by specific antibodies for triple-helical antigenic determinants of different types of collagen resistant against conventional proteases were preserved, while non-helical domains, as well as the non-collagenous ECM proteins, could no longer be demonstrated . The fossil bat, although showing evidence of fibrous, collagen-like structures in conventional histology, revealed no collagenous or non-collagenous ECM proteins by any technique . It later turned out that this was due to the replacement of the original soft parts in these fossils by lawns of bacteria . These studies introduced immunological techniques into palaeontology and opened new approaches for studying physiologically- and pathologically-altered structures in tissues of animals and humans of considerable historical age. Trends Genet, 2001 Sep, 17(9), 528 - 35 Unfolding the role of chaperones and chaperonins in human disease; Slavotinek AM et al.; Molecular chaperones comprise several highly conserved families of related proteins, many of which are also heat shock proteins . Chaperone proteins are crucial for the maintenance of native protein conformation and recent research has demonstrated several mechanisms where defective chaperone proteins have pathogenic consequences . In this article, we describe the structure and function of chaperones in bacterial and eukaryotic cells, focusing on the chaperonin class of chaperones . We then summarize contemporary research concerning the role of these proteins in several human diseases, concentrating on the genes coding for chaperone and chaperonin proteins and the importance of chaperones in neurodegenerative diseases and as modifiers of amino acid substitution mutations in other proteins. Mar Pollut Bull, 2001 Aug, 42(8), 667 - 72 Effects of PCBs on reactive oxygen species (ROS) production by the immune cells of Paracentrotus lividus (Echinodermata); Coteur G et al.; The impact of four PCB congeners: 3,3',4,4'-tetrachlorobiphenyl (IUPAC congener #77), 3,3',4,4',5-pentachlorobiphenyl (IUPAC #126), 2,2',4,4',5,5'-hexachlorobiphenyl (IUPAC #153) and 3,3',4,4',5,5'-hexachlorobiphenyl (IUPAC #169) was investigated on the reactive oxygen species (ROS) production by coelomocytes of the echinoid Paracentrotus lividus, an important species in marine benthic ecosystems . PCBs were found to increase ROS production and to delay the time of peak production . These effects were stronger on bacteria-stimulated cells and were congener-specific: coplanar congeners (#77, 126 and 169) had more effect than the non-coplanar PCB #153 . Among coplanar congeners, PCB #169 showed dose-dependent effects whereas PCB #77 and 126 were more toxic at high and low doses, respectively . The relative immunotoxicity of the different PCB congeners is discussed in the light of their structural properties and biological affinities. Microsc Res Tech, 2001 Jun 15, 53(6), 419 - 24 Immune response to autologous and heterologous Helicobacter pylori antigens in humans; Jakob B et al.; Infection of humans with Helicobacter pylori results in the development of chronic gastritis and plays an important role in gastric ulcer pathogenesis . Despite the infiltration of the mucosa with specific immunocompetent cells and production of specific antibodies, the infection usually persists for life . This study was performed to investigate if immunologic mechanisms exist which could contribute to the inability of the host to terminate the infection . Therefore, we compared the in vitro immunoreactivity of peripheral blood mononuclear cells (PBMC) from H . pylori-infected patients after stimulation with sonicated H . pylori bacteria from the stomach of the patient (autologous bacterial strain) with stimulation by bacteria from other patients (heterologous bacteria) . We measured cell proliferation, expression of T cell activation markers CD25, HLA-DR, and CD71, as well as production ofinterleukin-10 (IL-10), an inhibitory cytokine . We found that the proliferative response of PBMC was significantly lower after autologous than after heterologous stimulation . Furthermore, secretion of IL-10 in the culture supernatants was significantly higher when PBMC were incubated with autologous than with heterologous H . pylori antigens . No significant differences between autologous or heterologous stimulation were observed in the increased expression of T cell activation markers . These data indicate that systemic immunologic response to H . pylori are strain-dependent . For further studies of the immune responses towards H . pylori, the use of an autologous stimulatory system seems necessary. Nat Struct Biol, 2001 Sep, 8(9), 779 - 83 Crystal structure of Mip, a prolylisomerase from Legionella pneumophila; Riboldi-Tunnicliffe A et al.; The human pathogen Legionella pneumophila, the etiological agent of the severe and often fatal Legionnaires' disease, produces a major virulence factor, termed 'macrophage infectivity potentiator protein' (Mip), that is necessary for optimal multiplication of the bacteria within human alveolar macrophages . Mip exhibits a peptidyl prolyl cis-trans isomerase (PPIase) activity, which appears to be important for infection . Here we report the 2.4 A crystal structure of the Mip protein from L . pneumophila Philadelphia 1 and the 3.2 A crystal structure of its complex with the drug FK506 . Each monomer of the homodimeric protein consists of an N-terminal dimerization module, a long (65 A) connecting alpha-helix and a C-terminal PPIase domain exhibiting similarity to human FK506-binding protein . In view of the recent significant increase in the number of reported cases of Legionnaires' disease and other intracellular infections, these structural results are of prime interest for the design of new drugs directed against Mip proteins of intracellular pathogens. Phytochemistry, 2001 Sep, 58(1), 59 - 66 Purification and characterization of two alpha-amylase inhibitors from seeds of tepary bean (Phaseolus acutifolius A . Gray); Yamada T et al.; Two proteinaceous alpha-amylase inhibitors termed alphaAI-Pa1 and alphaAI-Pa2 were purified from seeds of a cultivated tepary bean (Phaseolus acutifolius A . Gray, cv . PI311897) . The two inhibitors differed in their specificity towards alpha-amylases of insect pests such as bruchids, although neither showed any inhibitory activity against alpha-amylases of mammalian, bacterial or fungal origin . AlphaAI-Pa2 resembles two common bean inhibitors, alphaAI-1 and alphaAI-2, in several characteristics such as N-terminal amino acid sequences and oligomeric structure being composed of alpha and beta subunits . In contrast alphaAI-Pa1 is composed of a single glycopolypeptide with a molecular mass of 35 kDa, and its N-terminal amino acid sequence resembled that of seed lectins in tepary bean and common bean . The information on the two tepary bean alpha-amylase inhibitors may be useful not only for providing insight into critical structure for the specificity towards different alpha-amylase enzymes but also for enhancing insect resistance in crops. J Clin Laser Med Surg, 2001 Aug, 19(4), 193 - 8 The use of Er:YAG, Nd:YAG and Ga-Al-As lasers in periapical surgery: a 3-year clinical study; Gouw-Soares S et al.; OBJECTIVES: In an attempt to increase the successful rate of endodontic surgical procedures this study proposes the use of an association of three lasers in apicectomy: Er:YAG laser, (wavelength 2.94 microm pulse mode), Nd:YAG laser (wavelength 1.064 microm, pulse mode), and Ga-Al-As laser, (wavelength of 790 nm, continuous wave) . BACKGROUND DATA: Previous studies have shown the low success rate of apicectomy by conventional methods due to the presence of remaining bacteria in the surgical site . METHODS: The Er:YAG laser was used to perform osteotomy and root resection without vibration, discomfort, less contamination of the surgical site, and no smear-layer on the dentine surface . The Nd:YAG laser irradiation through a fiber performed sealing of the dentinal tubules and bacterial reduction of the cavity bone . In addition, the improvement of healing and better post-operative achieved with the Ga-Al-As laser encourages the use of those lasers in periapical surgeries . RESULTS: Three years follow-up examination of the clinical case showed radiographically significant decrease of the radiolucent periapical area and no clinical signs and symptoms . CONCLUSION: The outcome of this clinical case indicates that the use of those lasers could be considered an alternative, suitable, and useful method to perform an apicectomy. Mol Genet Genomics, 2001 Aug, 265(6), 1050 - 9 Dual control of the nodA operon of Azorhizobium caulinodans ORS571 by a nod box and a NifA-sigma54-type promoter; Gao M et al.; Earlier studies have shown that the Azorhizohium caulinodans nodA promoter is controlled by a host plant-derived flavonoid signal via the transcription activator NodD . Here, we report that the transcription of the nodA operon is also under the control of NifA-RpoN . A NifA-sigma54-type promoter, P2nodA, is present upstream of the nod-box consensus motif of the nodA gene and directs expression of a nodA-uidA reporter gene both in free-living bacteria under nitrogen fixation conditions and in bacteroids . Mutation of P2nodA reduced, under certain conditions, the efficiency of nodulation and accelerated nodule senescence, suggesting that the dual control may help to optimize nodule initiation and function in the natural context of the symbiosis. Protein Eng, 2001 Jul, 14(7), 465 - 72 A Web-based classification system of DNA-binding protein families; Karmirantzou M et al.; Rational classification of proteins encoded in sequenced genomes is critical for making the genome sequences maximally useful for functional and evolutionary studies . The family of DNA-binding proteins is one of the most populated and studied amongst the various genomes of bacteria, archaea and eukaryotes and the Web-based system presented here is an approach to their classification . The DnaProt resource is an annotated and searchable collection of protein sequences for the families of DNA-binding proteins . The database contains 3238 full-length sequences (retrieved from the SWISS-PROT database, release 38) that include, at least, a DNA-binding domain . Sequence entries are organized into families defined by PROSITE patterns, PRINTS motifs and de novo excised signatures . Combining global similarities and functional motifs into a single classification scheme, DNA-binding proteins are classified into 33 unique classes, which helps to reveal comprehensive family relationships . To maximize family information retrieval, DnaProt contains a collection of multiple alignments for each DNA-binding family while the recognized motifs can be used as diagnostically functional fingerprints . All available structural class representatives have been referenced . The resource was developed as a Web-based management system for online free access of customized data sets . Entries are fully hyperlinked to facilitate easy retrieval of the original records from the source databases while functional and phylogenetic annotation will be applied to newly sequenced genomes . The database is freely available for online search of a library containing specific patterns of the identified DNA-binding protein classes and retrieval of individual entries from our WWW server . Vet Parasitol, 2001 Sep 12, 100(1-2), 87 - 103 An update on antileishmanial vaccine candidates and prospects for a canine Leishmania vaccine; Gradoni L; Dogs are the domestic reservoir for Leishmania infantum, the parasite causing zoonotic visceral leishmaniasis (VL) in both the Old and New Worlds . Since the available methods for canine leishmaniasis treatment and control have limited efficacy, the development of a canine Leishmania vaccine is highly desirable . Mechanisms of antileishmanial immune responses in murine, human, and canine infections are briefly presented . Vaccine candidates, including live or killed parasites, Leishmania purified fractions, defined recombinant parasite antigens, live recombinant bacteria expressing Leishmania antigens and antigen-encoding DNA plasmids, are reviewed . Finally, some practical requirements for the evaluation of vaccine candidates in dogs are indicated. FEBS Lett, 2001 Aug 24, 504(1-2), 31 - 5 Requirement of ceramide for adhesion of Helicobacter pylori to glycosphingolipids; Tang W et al.; Direct adhesion of Helicobacter pylori to immobilized glycosphingolipids (GSLs) was compared to that of their corresponding oligosaccharide-conjugated neoglycoconjugates in order to clarify the roles of the carbohydrate and lipid portions of GSLs in H . pylori adhesion . These bacteria were found to adhere to sulfatide, GM3, GalCer and LacCer, but not to ceramide, sphingomyelin, or polyacrylamides conjugated with beta-galactose, lactose, 3'-sialyllactose or 3'-sulfo-beta-galactose . Furthermore, neoglycolipids or bovine serum albumin derivatives with corresponding oligosaccharides were unable to serve as the ligands . H . pylori adhesion to GalCer with alpha-hydroxyl fatty acid was much stronger than GalCer with the non-hydroxyl fatty acid . These results suggest that H . pylori recognize the conformation of GSL with alpha-hydroxyl fatty acid on solid phase. J Chromatogr A, 2001 Jul 27, 924(1-2), 59 - 70 Bonded dimethylacrylamide as a permanent coating for capillary electrophoresis; Wan H et al.; A method for coating capillaries for capillary electrophoresis with chemically bonded polydimethylacrylamide has been developed, and the properties of the capillaries have been evaluated . The coated capillaries provided high separation efficiency, 12 x 10(5) theoretical plates/m was obtained for cytochrome c . The electroosmotic flow at pH 8.0 was 10 x 10(-10) to 6 x 10(-10) m2 V(-1) s(-1) . The coated capillaries were quite stable at high pH . At least 150 runs could be done at pH 10 without appreciable performance deterioration . The excellent performance of the coated capillaries was illustrated by separation of basic proteins, acidic proteins, 9-fluorenylmethyl chloroformate-derivatized neurotransmitter amino acids, peptide reference mixtures and peptides digested from a bacteria protein. Gastroenterol Clin Biol, 2001 May, 25(5), 543 - 5 {Endoscopic aspect of ulcerated tumor-like gastritis associated with Helicobacter heilmannii}; Texereau P et al.; We report on 5 cases with an endoscopic aspect exceptionally described of ulcerated tumor-like gastritis associated with Helicobacter heilmannii . This rare but ubiquitary bacteria, belonging to the same family as Helicobacter pylori, is epidemiologically and structuraly different . When these endoscopic lesions are detected, Helicobacter heilmannii has to be looked for carefully . The treatment, which is the same than for Helicobacter pylori, must lead to complete repair of endoscopic and histologic lesions. J Periodontal Res, 2001 Aug, 36(4), 252 - 9 Reduced dental plaque accumulation on composite gold alloy margins; Goodson JM et al.; Restoration of tooth surfaces with materials that inhibit formation of heavy bacterial plaque accumulations could be important in the treatment of patients with existing oral disease or in reducing the likelihood for periodontal disease . Captek is a dental gold composite material used to produce copings for ceramometal restorations that has been reported to inhibit plaque accumulation . In this study, the oral bacteria of nine periodontally healthy subjects with a total of 42 gold composite copings were sampled . Contralateral teeth with normal tooth surfaces were also sampled as controls . The quantitative presence of forty bacteria was determined in each sample by DNA:DNA hybridization . The results indicated that the porcelain/gold composite alloy coping surfaces had significantly fewer bacteria than the control normal tooth surfaces (71% reduction) . The percentage composition, however, did not differ significantly between surfaces. J Biol Chem, 2001 Nov 16, 276(46), 42639 - 44 Epub 2001 Aug 22. Identification of a new class of molecules, the arachidonyl amino acids, and characterization of one member that inhibits pain; Huang SM et al.; In mammals, specific lipids and amino acids serve as crucial signaling molecules . In bacteria, conjugates of lipids and amino acids (referred to as lipoamino acids) have been identified and found to possess biological activity . Here, we report that mammals also produce lipoamino acids, specifically the arachidonyl amino acids . We show that the conjugate of arachidonic acid and glycine (N-arachidonylglycine (NAGly)) is present in bovine and rat brain as well as other tissues and that it suppresses tonic inflammatory pain . The biosynthesis of NAGly and its degradation by the enzyme fatty acid amide hydrolase can be observed in rat brain tissue . In addition to NAGly, bovine brain produces at least two other arachidonyl amino acids: N-arachidonyl gamma-aminobutyric acid (NAGABA) and N-arachidonylalanine . Like NAGly, NAGABA inhibits pain . These findings open the door to the identification of other members of this new class of biomolecules, which may be integral to pain regulation and a variety of functions in mammals. J Mol Biol, 2001 Aug 24, 311(4), 639 - 56 SNAPping up functionally related genes based on context information: a colinearity-free approach; Kolesov G et al.; We describe a computational approach for finding genes that are functionally related but do not possess any noticeable sequence similarity . Our method, which we call SNAP (similarity-neighborhood approach), reveals the conservation of gene order on bacterial chromosomes based on both cross-genome comparison and context information . The novel feature of this method is that it does not rely on detection of conserved colinear gene strings . Instead, we introduce the notion of a similarity-neighborhood graph (SN-graph), which is constructed from the chains of similarity and neighborhood relationships between orthologous genes in different genomes and adjacent genes in the same genome, respectively . An SN-cycle is defined as a closed path on the SN-graph and is postulated to preferentially join functionally related gene products that participate in the same biochemical or regulatory process . We demonstrate the substantial non-randomness and functional significance of SN-cycles derived from real genome data and estimate the prediction accuracy of SNAP in assigning broad function to uncharacterized proteins . Examples of practical application of SNAP for improving the quality of genome annotation are described . Tsitologiia, 2001, 43(5), 520 - 8 {Analysis of natural diversity of symbiotic relationships in the Paramecium bursaria--Holospora curviuscula system}; Skoblo II et al.; Bacteria of the genus Holospora belong to obligatory endonucleobionts of ciliates of the genus Paramecium . The bacteria show specificity towards the particular host species and the types of nuclei they infect: macro- or micronuclei . During a long-term screening of P . bursaria clones, belonging to three different syngens, Holospora inhibited cells of two syngens only . Using the number of host clones and symbiont isolates, it was shown that H . curviuscula was unable to pass successfully through the syngen barrier even under experimental infection . Considering the species level of specificity in Holospora associations of P . caudatum we suggest the existence of a greater evolutionary divergence in P . bursaria syngens than in syngens of P . caudatum . We have revealed that in incompatible combinations "host clone--symbionts isolate" the complicated bacterial life cycle may be blocked at definite stages depending on genetic features of both partners . Thus, the recognition of the full block spectrum could break the continuous infection process down to independently controlled steps . The block spectrum revealed in the system of P . bursaria--H . curviuscula demonstrates its significant similarity to block spectra of other systems within the Holospora--Paramecium complex . A block of transverse binding formation has been first revealed in Holospora dividing in the nucleus. Mutat Res, 2001 Sep 4, 486(4), 217 - 47 Repair of DNA interstrand cross-links; Dronkert ML et al.; DNA interstrand cross-links (ICLs) are very toxic to dividing cells, because they induce mutations, chromosomal rearrangements and cell death . Inducers of ICLs are important drugs in cancer treatment . We discuss the main properties of several classes of ICL agents and the types of damage they induce . The current insights in ICL repair in bacteria, yeast and mammalian cells are reviewed . An intriguing aspect of ICLs is that a number of multi-step DNA repair pathways including nucleotide excision repair, homologous recombination and post-replication/translesion repair all impinge on their repair . Furthermore, the breast cancer-associated proteins Brca1 and Brca2, the Fanconi anemia-associated FANC proteins, and cell cycle checkpoint proteins are involved in regulating the cellular response to ICLs . We depict several models that describe possible pathways for the repair or replicational bypass of ICLs. Adv Drug Deliv Rev, 2001 Sep 23, 51(1-3), 161 - 71 Nasal delivery of epitope based vaccines; Olszewska W et al.; Essentially all of the currently available vaccines are based on the use of inactivated or live-attenuated pathogens . However, these vaccines have several shortcomings, such as difficulties of in vitro culturing, biohazard risks, as well as loss of efficacy due to the genetic variations seen in many viruses . These problems may potentially be solved by immunising with epitope-based vaccines consisting of rationally designed protective epitopes, appropriately presented and easy to deliver, which are capable of stimulating effective B-cell, T-cell and cytotoxic immune responses whilst avoiding potentially hazardous and undesirable effects . Furthermore, the use of a mixture of defined epitopes could lead to an effective broad range immune response which has the potential to overcome both strain specificity of the pathogen and the MHC restriction of the host . Epitope-based vaccines can be designed to involve the use of synthetic materials that can be available in unlimited quantities and posing no biohazard . Other approaches include the use of naked DNA or recombinant viruses or bacteria expressing the epitopes . An important objective in the development of such vaccines is that they should be effective when delivered via the mucosal route and effective in the presence of maternal antibodies . In this review, we present examples of the use of various epitope-based vaccine constructs, focussing particularly upon their intranasal delivery to the immune system. Adv Drug Deliv Rev, 2001 Sep 23, 51(1-3), 43 - 54 Manipulating the immune system: humoral versus cell-mediated immunity; McNeela EA et al.; Many of the vaccines in use today were designed on an empirical basis with little understanding of the mechanism of protective immunity or knowledge of the protective antigens . Certain of these vaccines, based on killed or attenuated bacteria or viruses, are associated with unacceptable side-effects . New generation vaccines based on recombinant proteins or naked DNA have considerably improved safety profiles, but are often poorly immunogenic, especially when administered by mucosal routes . This is a particular problem with oral delivery; where high doses of antigen are required to generate even modest immune responses . In contrast, nasal delivery of antigens with a range of adjuvants or delivery systems has been shown to generate relatively potent immune responses and to protect against infection in animal models . Advances in immunology have demonstrated that a variety of cellular and humoral immune effector mechanisms, that are regulated by distinct Th1 and Th2 subtypes of T cells, mediate protection against different infectious diseases . The identification of adjuvants and immunomodulators, that can promote the selective induction of these distinct populations of T cells, has now made it possible to rationally design safe and effective mucosal vaccines against a range of infectious diseases of man. Neuron, 2001 Aug 16, 31(3), 381 - 94 Asynchronous synapse elimination in neonatal motor units: studies using GFP transgenic mice; Keller-Peck CR et al.; In developing muscle, synapse elimination reduces the number of motor axons that innervate each postsynaptic cell . This loss of connections is thought to be a consequence of axon branch trimming . However, branch retraction has not been observed directly, and many questions remain, such as: do all motor axons retract branches, are eliminated branches withdrawn synchronously, and are withdrawing branches localized to particular regions? To address these questions, we used transgenic mice that express fluorescent proteins in small subsets of motor axons, providing a unique opportunity to reconstruct complete axonal arbors and identify all the postsynaptic targets . We found that, during early postnatal development, each motor axon loses terminal branches, but retracting branches withdraw asynchronously and without obvious spatial bias, suggesting that local interactions at each neuromuscular junction regulate synapse elimination. Neuron, 2001 Aug 16, 31(3), 353 - 65 Regulation of neuronal traits by a novel transcriptional complex; Ballas N et al.; The transcriptional repressor, REST, helps restrict neuronal traits to neurons by blocking their expression in nonneuronal cells . To examine the repercussions of REST expression in neurons, we generated a neuronal cell line that expresses REST conditionally . REST expression inhibited differentiation by nerve growth factor, suppressing both sodium current and neurite growth . A novel corepressor complex, CoREST/HDAC2, was shown to be required for REST repression . In the presence of REST, the CoREST/HDAC2 complex occupied the native Nav1.2 sodium channel gene in chromatin . In neuronal cells that lack REST and express sodium channels, the corepressor complex was not present on the gene . Collectively, these studies define a novel HDAC complex that is recruited by the C-terminal repressor domain of REST to actively repress genes essential to the neuronal phenotype. Philos Trans R Soc Lond B Biol Sci, 2001 Jul 29, 356(1411), 983 - 9 Risk factors for human disease emergence; Taylor LH et al.; A comprehensive literature review identifies 1415 species of infectious organism known to be pathogenic to humans, including 217 viruses and prions, 538 bacteria and rickettsia, 307 fungi, 66 protozoa and 287 helminths . Out of these, 868 (61%) are zoonotic, that is, they can be transmitted between humans and animals, and 175 pathogenic species are associated with diseases considered to be 'emerging' . We test the hypothesis that zoonotic pathogens are more likely to be associated with emerging diseases than non-emerging ones . Out of the emerging pathogens, 132 (75%) are zoonotic, and overall, zoonotic pathogens are twice as likely to be associated with emerging diseases than non-zoonotic pathogens . However, the result varies among taxa, with protozoa and viruses particularly likely to emerge, and helminths particularly unlikely to do so, irrespective of their zoonotic status . No association between transmission route and emergence was found . This study represents the first quantitative analysis identifying risk factors for human disease emergence. Am Fam Physician, 2001 Aug 1, 64(3), 461 - 6 Tick-borne diseases; Gayle A et al.; Tick-borne diseases are the most common vector-borne illnesses in the United States . Lyme disease is the most common, but several others also occur . The ehrlichioses have only been identified as agents of human disease in the United States in the past few decades, and knowledge about them is still evolving . Rocky Mountain spotted fever is relatively common and can be severe, especially in children, if the diagnosis is not made quickly . Tularemia has long been known to cause disease in humans, but there is renewed interest because of its potential as a biologic warfare agent . These diseases can be severe or even fatal . Most of them are easily treatable when identified early . These diseases result from a variety of infectious agents including bacteria, rickettsia, viruses and protozoa, or they may be caused by substances produced by the tick . Most of these diseases present initially with nonspecific symptoms and are often difficult to recognize . Few definitive diagnostic tests are available . Therefore, knowledge of the epidemiology and common presentations, as well as the diagnostic options and treatments available, are important issues for family physicians. Int Immunopharmacol, 2001 Aug, 1(8), 1513 - 24 Natural killer cells and nitric oxide; Cifone MG et al.; Natural killer (NK) cells and nitric oxide (NO) are both important components of the natural or innate immune response . NK cells are large granular lymphocytes capable of destroying cells infected by virus or bacteria and susceptible tumor cells without prior sensitization and restriction by MHC antigens . They are abundant in blood, spleen, liver and lungs and are distinct from both T and B lymphocytes in their circulation patterns, profile of surface antigens, receptor repertoire and the way in which they discriminate between self and non-self . Uniquely, NK cells express receptors that can recognize and discriminate between normal and altered MHC class I determinants . NK cell cytotoxic activity is strongly induced by cytokines such as IL-2 and IL-12, and this activation is associated with synthesis of NO . Inhibitors of NO synthesis impair NK cell-mediated target cell killing, demonstrating a role for NO in NK cell function . Furthermore, NO itself can regulate NK cell activation . In this article, evidence that NO is a mediator of NK cell-mediated target cell killing, and that NO is a regulator of NK cell activation will be reviewed . Results of NO synthase gene deletion studies will be discussed, and rodent and human NK cells will be compared. Int Immunopharmacol, 2001 Aug, 1(8), 1501 - 12 The physiological role and pharmacological potential of nitric oxide in neutrophil activation; Armstrong R; There is contention over whether human neutrophils produce physiologically significant levels of nitric oxide (NO) during inflammatory reactions . Nevertheless, regardless of its cell source, NO does exert regulatory effects on neutrophil function . Depending on experimental conditions, NO can either inhibit or enhance neutrophil activation, in both cases probably acting through cyclic GMP . The explanation for these apparently contradictory findings may be that the effect depends upon the concentration of NO: low concentrations of NO being stimulatory and high concentrations inhibitory . Nitrite, produced at high concentrations from NO during inflammation, can react with neutrophil myeloperoxidase-derived hypochlorous acid (HOCl) to form the active oxidant nitryl chloride, a species capable of nitrating tyrosine and tyrosyl residues on proteins . Whether nitryl chloride acts to limit or amplify the oxidant effects of myeloperoxidase is not yet clear, although formation of nitrotyrosine has been linked with nitration of phagocytosed bacteria . Clearly, a better understanding of the inflammatory effects of NO on neutrophils is needed before the therapeutic potential of NO donors or inhibitors in inflammation can be realised. Mt Sinai J Med, 2001 Sep-Oct, 68(4-5), 279 - 86 The modern age of acne therapy: a review of current treatment options; Bershad SV; This review of current acne treatments begins with the crucial discovery in 1979 of isotretinoin treatment for nodulocystic acne . This drug s approval in 1982 revolutionized therapy, since it was the first oral acne-specific drug, and it provided prolonged remissions . In addition, it may prevent the emergence of resistant bacteria, a problem linked to the traditional use of antibiotics for acne . Patients who are not candidates for isotretinoin therapy may benefit from one of the other drugs or drug combinations reviewed, including the third-generation topical retinoids adapalene and tazarotene, retinoic acid reformulated in new vehicles, azelaic acid, and topical antibiotics . Proper selection and education of patients are essential, since serious consequences may result from poorly monitored use of antibiotics and retinoid. J Bacteriol, 2001 Sep, 183(18), 5325 - 33 Noncatalytic docking domains of cellulosomes of anaerobic fungi; Steenbakkers PJ et al.; A method is presented for the specific isolation of genes encoding cellulosome components from anaerobic fungi . The catalytic components of the cellulosome of anaerobic fungi typically contain, besides the catalytic domain, mostly two copies of a 40-amino-acid cysteine-rich, noncatalytic docking domain (NCDD) interspaced by short linkers . Degenerate primers were designed to anneal to the highly conserved region within the NCDDs of the monocentric fungus Piromyces sp . strain E2 and the polycentric fungus Orpinomyces sp . strain PC-2 . Through PCR using cDNA from Orpinomyces sp . and genomic DNA from Piromyces sp . as templates, respectively, 9 and 19 PCR products were isolated encoding novel NCDD linker sequences . Screening of an Orpinomyces sp . cDNA library with four of these PCR products resulted in the isolation of new genes encoding cellulosome components . An alignment of the partial NCDD sequence information obtained and an alignment of database-accessible NCDD sequences, focusing on the number and position of cysteine residues, indicated the presence of three structural subfamilies within fungal NCDDs . Furthermore, evidence is presented that the NCDDs in CelC from the polycentric fungus Orpinomyces sp . strain PC-2 specifically recognize four proteins in a cellulosome preparation, indicating the presence of multiple scaffoldins. Trends Microbiol, 2001 Aug, 9(8), 397 - 403 Divalent-metal transport by NRAMP proteins at the interface of host-pathogen interactions; Forbes JR et al.; The NRAMP family of divalent-metal transporters plays a key role in the homeostasis of iron and other metals . NRAMP2 (DMT1) acts as an iron-uptake protein in both the duodenum and in peripheral tissues . NRAMP1 functions as a divalent-metal efflux pump at the phagosomal membrane of macrophages and neutrophils, and mutations in NRAMP1 cause susceptibility to several intracellular pathogens . NRAMP homologues have been identified in bacteria and are involved in acquiring divalent metals from the extracellular environment . Interestingly, bacterial and mammalian NRAMP proteins would compete for the same essential substrates within the microenvironment of the phagosome, at the interface of host-pathogen interactions. Ann Occup Hyg, 2001 Aug, 45(6), 493 - 8 Recognition errors in the quantification of micro-organisms by fluorescence microscopy; Eduard W et al.; OBJECTIVES: An interlaboratory comparison of fluorescence microscopic counting of micro-organisms was carried out to assess counting errors in the measurement of micro-organisms in bioaerosols generated during handling of municipal waste . METHODS: Series of 27 replicate samples were collected in the work environment with a modified field exposure chamber . The preparation methods of three Scandinavian laboratories were compared . Four microscopists from these laboratories performed the counts which were also compared . Duplicate counting of identical microscopic fields allowed the assessment of recognition errors . RESULTS: The field exposure chamber collected replicate samples with a relative standard deviation of 5% when particles < or = 15 microm aerodynamic diameter were collected . Storage time of 40-200 days had no significant influence on the total micro-organism count . Differences between preparation methods were from 2 to 35% for bacteria, and from 15 to 35% for fungal spores when samples were analysed in Oslo; the results for fungal spore counts were significantly different (P < 0.01) . These differences were not confirmed when samples were analysed in Umea, Copenhagen and Oslo using those laboratories methods . These results can be explained by less efficient redispersion of aggregates when the Umea and Copenhagen methods were recreated in Oslo yielding a greater number of innumerable aggregates . Differences between microscopists were minor for fungal spores (2-12%) but substantial for bacteria (4-53%) . A major source of error was the recognition of bacteria which had a relative standard deviation (rsd) of 37% although a lower size limit of 0.75 microm was adopted for counting of bacteria . Fungal spores were recognised with much better precision (rsd 9%) . CONCLUSIONS: Recognition errors of bacteria may be substantial and more specific fluorochromes are needed for fluorescence microscopic counting of micro-organisms. Biochemistry, 2001 Aug 28, 40(34), 10382 - 91 Sequence requirements of the ATP-binding site within the C-terminal nucleotide-binding domain of mouse P-glycoprotein: structure-activity relationships for flavonoid binding; de Wet H et al.; Sequence requirements of the ATP-binding site within the C-terminal nucleotide-binding domain (NBD2) of mouse P-glycoprotein were investigated by using two recombinantly expressed soluble proteins of different lengths and photoactive ATP analogues, 8-azidoadenosine triphosphate (8N(3)-ATP) and 2',3',4'-O-(2,4,6-trinitrophenyl)-8-azidoadenosine triphosphate (TNP-8N(3)-ATP) . The two proteins, Thr(1044)-Thr(1224) (NBD2(short)) and Lys(1025)-Ser(1276) (NBD2(long)), both incorporated the four consensus sequences of ABC (ATP-binding cassette) transporters, Walker A and B motifs, the Q-loop, and the ABC signature, while differing in N-terminal and C-terminal extensions . Radioactive photolabeling of both proteins was characterized by hyperbolic dependence on nucleotide concentration and high-affinity binding with K(0.5)(8N(3)-ATP) = 36-37 microM and K(0.5)(TNP-8N(3)-ATP) = 0.8-2.6 microM and was maximal at acidic pH . Photolabeling was strongly inhibited by TNP-ATP (K(D) = 0.1-5 microM) and ATP (K(D) = 0.5-2.7 mM) . Since flavonoids display bifunctional interactions at the ATP-binding site and a vicinal steroid-interacting hydrophobic sequence {Conseil, G., Baubichon-Cortay, H., Dayan, G., Jault, J.-M., Barron, D., and Di Pietro, A . (1998) Proc . Natl . Acad . Sci . U.S.A . 95, 9831-9836}, a series of 30 flavonoids from different classes were investigated for structure-activity relationships toward binding to the ATP site, monitored by protection against photolabeling . The 3-OH and aromaticity of conjugated rings A and C appeared important, whereas opening of ring C abolished the binding in all but one case . It can be concluded that the benzopyrone portion of the flavonoids binds at the adenyl site and the phenyl ring B at the ribosyl site . The Walker A and B motifs, intervening sequences, and small segments on both sides are sufficient to constitute the ATP site. Chemosphere, 2001 Aug, 44(5), 1169 - 76 Azo dye decolourisation by anaerobic granular sludge; van der Zee FP et al.; The decolourisation of 20 selected azo dyes by granular sludge from an upward-flow anaerobic sludge bed (UASB) reactor was assayed . Complete reduction was found for all azo dyes tested, generally yielding colourless products . The reactions followed first-order kinetics and reaction rates varied greatly between dyes: half-life times ranged from 1 to about 100 h . The slowest reaction rates were found for reactive dyes with a triazine reactive group . There was no correlation between a dye's half-life time and its molecular weight, indicating that cell penetration was probably not an important factor . Since granular sludge contains sulphide, eight dyes were also monitored for direct chemical decolourisation by sulphide . All these dyes were reduced chemically albeit at slower rates than in the presence of sludge at comparable sulphide levels . Increasing sulphide concentrations, even when present in huge excess, stimulated the azo reduction rate . The results indicate that granular sludge can decolourise a broad spectrum of azo dye structures due to non-specific extracellular reactions . Reducing agents (e.g., sulphide) in sludge play an important role . The presence of anaerobic biomass is probably beneficial for maintaining the pools of these reduced compounds. J Synchrotron Radiat, 2001 Mar 1, 8(Pt 2), 978 - 80 Time-dependent XAS studies of trapped enzyme-substrate complexes of alcohol dehydrogenase from Thermoanaerobacter brockii; Kleifeld O et al.; The understanding of structure-function relationships in proteins has been significantly advanced with the advent of the biotechnological revolution . A goal yet to be realized for many metalloenzyme systems is to characterize the dynamic changes in structure that bridge the static endpoints provided by crystallography . We present here a series of edge and EXAFS spectra of the metalloenzyme alcohol dehydrogenase from Thermoanaerobacter brockii (TbADH) complexed with its substrate . The enzyme-substrate complexes were trapped by fast freezing at various times, following their enzyme activity . Our edge and EXAFS analyses both reveal the time-dependent changes in the structure of the active site of TbADH. Arch Microbiol, 2001 Sep, 176(3), 204 - 10 Characterization by genotypic methods of symbiotic Nostoc strains isolated from five species of Gunnera; Rasmussen U et al.; The genetic diversity of ten symbiotic Nostoc strains isolated from different Gunnera species was investigated . The strains were analyzed using molecular methods with different taxonomic resolutions, including restriction fragment length polymorphisms (RFLP) of the PCR-amplified 16S ribosomal gene and the 16S-23S internal transcribed spacer (ITS) region combined with computer-assisted analyses . The functional gene hetR, assigned to heterocyst differentiation, was used for denaturing gradient gel electrophoresis . A high genetic diversity was observed among the isolates even in the conserved gene coding for the small ribosomal unit . No correlation was observed between clustering of cyanobacteria and the host species of Gunnera. Arch Microbiol, 2001 Sep, 176(3), 165 - 9 Two distinct enzyme systems are responsible for tetrachloroethene and chlorophenol reductive dehalogenation in Desulfitobacterium strain PCE1; van de Pas BA et al.; Desulfitobacterium strain PCE1 is able to use tetrachloroethene and chloroaromatics as terminal electron acceptors for growth . Cell extracts of Desulfitobacterium strain PCE1 grown with tetrachloroethene as electron acceptor showed no dehalogenase activity with 3-chloro-4-hydroxyphenylacetate (Cl-OH-phenylacetate) and other ortho-chlorophenolic compounds in an in vitro assay . Extracts of cells that were grown with Cl-OH-phenylacetate as electron acceptor dechlorinated tetrachloroethene at 10% of the dechlorination rate of Cl-OH-phenylacetate . In both cell extracts dechlorination was inhibited by the addition of 1-iodopropane and dinitrogen oxide, inhibitors of cobalamin-containing enzymes . The enzymes responsible for tetrachloroethene and Cl-OH-phenylacetate dechlorination were partially purified . A 100-fold enriched fraction of chlorophenol reductive dehalogenase was obtained that mainly contained a protein with a subunit size of 48 kDa . The characteristics of this enzyme are similar to that of the chlorophenol reductive dehalogenase of D . dehalogenans . After partial purification of the tetrachloroethene reductive dehalogenase, a fraction was obtained that also contained a 48-kDa protein, but the N-terminal sequence showed no similarity with that of the chlorophenol reductive dehalogenase sequence or with the N-terminal amino acid sequence of tetra- and trichloroethene reductive dehalogenase of Desulfitobacterium strain TCE1 . These results provide strong evidence that two different enzymes are responsible for tetrachloroethene and chlorophenol dechlorination in Desulfitobacterium strain PCE1 . Furthermore, the characterization of partially purified tetrachloroethene reductive dehalogenase indicated that this enzyme is a novel type of reductive dehalogenase. Genes Dev, 2001 Aug 15, 15(16), 2069 - 82 Binding of c-Myc to chromatin mediates mitogen-induced acetylation of histone H4 and gene activation; Frank SR et al.; The Myc protein binds DNA and activates transcription by mechanisms that are still unclear . We used chromatin immunoprecipitation (ChIP) to evaluate Myc-dependent changes in histone acetylation at seven target loci . Upon serum stimulation of Rat1 fibroblasts, Myc associated with chromatin, histone H4 became locally hyperacetylated, and gene expression was induced . These responses were lost or severely impaired in Myc-deficient cells, but were restored by adenoviral delivery of Myc simultaneous with mitogenic stimulation . When targeted to chromatin in the absence of mitogens, Myc directly induced H4 acetylation . In addition, Myc recruited TRRAP to chromatin, consistent with a role for this cofactor in histone acetylation . Finally, unlike serum, Myc alone was very inefficient in inducing expression of most target genes . Myc therefore governs a step, most likely H4 acetylation, that is required but not sufficient for transcriptional activation . We propose that Myc acts as a permissive factor, allowing additional signals to activate target promoters. Genes Dev, 2001 Aug 15, 15(16), 2042 - 7 Regulation of cyclin D2 gene expression by the Myc/Max/Mad network: Myc-dependent TRRAP recruitment and histone acetylation at the cyclin D2 promoter; Bouchard C et al.; Myc oncoproteins promote cell cycle progression in part through the transcriptional up-regulation of the cyclin D2 gene . We now show that Myc is bound to the cyclin D2 promoter in vivo . Binding of Myc induces cyclin D2 expression and histone acetylation at a single nucleosome in a MycBoxII/TRRAP-dependent manner . Down-regulation of cyclin D2 mRNA expression in differentiating HL60 cells is preceded by a switch of promoter occupancy from Myc/Max to Mad/Max complexes, loss of TRRAP binding, increased HDAC1 binding, and histone deacetylation . Thus, recruitment of TRRAP and regulation of histone acetylation are critical for transcriptional activation by Myc. Histol Histopathol, 2001 Jul, 16(3), 855 - 60 Ultrastructural study of ovine pulmonary pasteurellosis: involvement of neutrophils and macrophages; Gazquez A et al.; Pasteurellosis is a common infectious disease characterised by fibrinous pneumonia and involving neutrophils and macrophages . This study aimed to determine the timing and extent of the pathogenic involvement of these cell elements in lesions induced in experimentally-infected lambs . A concentration of approximately 3x10(8) bacteria/ml . was inoculated into 30 two-month-old disease-free Merino lambs . Five lambs were assigned to each of five experimental batches, slaughtered on days 1, 3, 7, 11 and 15 following intratracheal inoculation, and to one control batch inoculated with a sterile solution . One control animal was slaughtered at the same time as each experimental batch . More characteristic lesions occur in bronchioles, peribronchial tissue and alveoli and are characterised by fibrinous processes . From the start of the experiment, epithelial-cell disruption and loss of microvilli were apparent; cell debris, desquamate cells and bacterial elements were observed in bronchiolar lumina, embedded in a fibrillar granular material . Alveolar structures displayed fewer neutrophils and macrophages, containing phagocytic vacuoles . Laminar bodies were apparent in type II pneumocytes . The interseptal area contained similar cell types, as well as abundant edema . In the course of the experiment, macrophage numbers increased in all the areas involved, with signs of intense phagocytic activity . The final phase of the experiment was characterised by a mild interseptal infiltrate and by clear alveolar lumina. Biologist (London) . 2001 Aug;48(4):163. Light of my life--messages in the dark; Meyer-Rochow VB; Luminescent lures, counter-shading in the dark blue sea, flashes of light intensive enough to temporarily blind a predator, love fireworks in the night to impress a mate, and toadstools that glow to attract parasitic wasps--these are just some of the many examples of bioluminescence at work in Nature . But how is the biological light produced? What are its evolutionary roots? Why are there so many different uses for the light? J Immunol, 2001 Sep 1, 167(5), 2651 - 6 Intestinal macrophages lack CD14 and CD89 and consequently are down-regulated for LPS- and IgA-mediated activities; Smith PD et al.; The intestinal mucosa normally displays minimal inflammation despite the close proximity between mucosal macrophages and lumenal bacteria . Macrophages interact with bacteria and their products through CD14, a surface receptor involved in the response to LPS, and CD89, the receptor for IgA (FcalphaR) . Here we show that resident macrophages isolated from normal human intestine lack CD14 and CD89 . The absence of CD14 and CD89 was not due to the isolation procedure or mucosal cell products, but was evident at the transcriptional level, as the macrophages expressed neither CD14- nor CD89-specific mRNAs, but did express Toll-like receptor 2 and 4 transcripts . Consistent with their CD14(-) phenotype, lamina propria macrophages displayed markedly reduced LPS-induced cytokine production and LPS-enhanced phagocytosis . In addition, IgA-enhanced phagocytosis was sharply reduced in lamina propria macrophages . Thus, the absence of CD14 and CD89 on resident intestinal macrophages, due to down-regulated gene transcription, causes down-modulated LPS- and IgA-mediated functions and probably contributes to the low level of inflammation in normal human intestinal mucosa. Acta Otolaryngol, 2001 Jun, 121(4), 517 - 22 Phagocytosis in the nasopharyngeal secretion by cells from the adenoid; Ivarsson M et al.; The aim of this study was to elucidate whether granulocytes and macrophages in surface secretion on the adenoid emanate from the adenoid and whether these cells participate in the control of the nasopharyngeal bacterial flora . Samples of the adenoid and its surface secretion were obtained during adenoidectomy from 12 children with recurrent acute otitis media, secretory otitis media or enlarged adenoids causing obstruction . Immunochemistry was used to examine the location of granulocytes and macrophages in the adenoid as well as the presence of IgA, IgM, IgG and plasma cells in the secretion . Phagocytosis in the secretion was examined in imprints stained with May Grunwald Giemsa . Acridine Orange and Gram staining were used to demonstrate the presence and location of bacteria in the secretion and mucosa . As a control, surface secretions were obtained from 12 children without any history of recurrent airway problems . Granulocytes and macrophages were observed in the epithelium of the adenoid and some of these cells penetrated the epithelial surface . Positive staining for IgA, IgM and IgG was observed in all secretions . In 10 of 12 children plasma cells were present in the secretion . Bacteria were observed in all imprints . With the exception of I child in each group phagocytosis of bacteria in the surface secretion was demonstrated from imprints in all children . We conclude that granulocytes and macrophages leave the adenoid and enter the surface secretion, where constant phagocytic activity takes place . The spatial relations between mononuclear and polymorphonuclear cells imply a possible cooperation between these cells in the overall control of the nasopharyngeal bacterial flora. J Clin Dent, 2001, 12(4), 104 - 7 The effect of an oral hygiene program on oral levels of volatile sulfur compounds (VSC); Seemann R et al.; Volatile sulfur compounds (VSCs) produced by bacteria in niches of the oral cavity play a major role in the etiology of bad breath, and can be easily detected by a portable sulfide monitor (Halimeter) . To investigate the effect of an oral hygiene program on VSC levels, Halimeter readings were taken from 55 healthy dental students during a course in oral hygiene training, including instruction on brushing, flossing and professional tooth cleaning . Ten students who received no oral hygiene training served as a negative control . The oral hygiene status was measured using the papillary bleeding index (PBI) . PBI and VSC values did not show significant changes during the study period of 10 weeks in the control group . In the test group, PBI values significantly decreased compared to baseline and the control, indicating that the oral hygiene program had a benefit on the oral hygiene status . The VSC values also decreased significantly during the study period compared to baseline and the control . It was concluded that in a group of dental students, a thorough oral hygiene training program was capable of reducing the oral level of VSC Halimeter readings. FEMS Microbiol Lett, 2001 Aug 7, 202(1), 31 - 8 Induction of iNOS in human monocytes infected with different Legionella species; Neumeister B et al.; The contribution of nitric oxide (NO) radicals to the suppression of intracellular replication of Legionella has been well established in rodents but remained questionable in humans . Considering the fact that human monocytes do not exhibit a high-output NO production, we used sensitive methods such as detection of inducible NO synthase (iNOS) mRNA by reverse transcription-PCR and demonstration of iNOS protein expression by means of flow cytometry and Western blot to compare the levels of iNOS induced by Legionella species which, in accordance to their human prevalence, show different multiplication rates within human monocytic cells . The expression of iNOS in Mono Mac 6 (MM6) cells showed an only moderate inverse correlation to the intracellular replication rate of a given Legionella species in the protein expression assays . However, stimulation of host cells with 1,25-dihydroxyvitamin D(3) to enhance NO production and inhibition of NO production by treatment of host cells with N(G)-methyl-L-arginine were not able to modify the intracellular multiplication of legionellae within MM6 cells . Therefore, NO production does not seem to play a crucial role for the restriction of intracellular replication of Legionella bacteria within human monocytic cells . Rodent models in investigations which are supposed to clarify the involvement of NO radicals in defense mechanisms against Legionella infections in humans are of doubtful significance. Environ Technol, 2001 Jul, 22(7), 855 - 67 Oxygen dynamics in crude oil contaminated salt marshes: II . Carbonaceous sediment oxygen demand model; Shin WS et al.; The role of carbonaceous sediment oxygen demand (CSOD) due to oxidation of sulfides reduced in oxygen dynamics in crude oil contaminated salt marshes was investigated through a mathematical model . An existing CSOD model was calibrated from laboratory data sets through nonlinear regression . The effect of oil and fertilizer on CSOD was quantified by comparing three treatments (i) control (no oil and fertilizer amended) (ii) fertilized, and (iii) oiled and fertilized sediments . CSOD was directly proportional to sulfate reduction . Higher CSODs under oiled/fertilized and fertilized conditions were primarily due to increased sulfate reduction rates under these conditions . Reaction velocity for oxidation of dissolved sulfide in the aerobic layer, kappaH2S,d1, was significantly greater than that of particulate sulfide oxidation, kappaH2S,p1 . This indicates that dissolved sulfides are dominant over particulate sulfides and directly related to CSOD in salt marshes . The CSOD was linearly dependent on the overlying dissolved oxygen concentration when crude oil and fertilizer were added. Mol Cell Biochem, 2001 May, 221(1-2), 71 - 7 Helicobacter infection and phospholipase A2 enzymes: effect of Helicobacter felis-infection on the expression and activity of sPLA2 enzymes in mouse stomach; Ottlecz A et al.; The murine gastric mucosa possesses very high secretory type phospholipase A2 activity . Northern and Western blots indicated that the pancreatic-type, sPLA2-IB represents the predominant form of sPLA2 enzymes present in the gastric mucosa . Both sPLA2-IB mRNA and protein in the gastric mucosa exceeded levels found in the pancreas, and in contrast to the pancreatic enzyme it was present primarily in the active state . The sPLA2-IB gene is not expressed in the murine small intestine and colon . Infection by the gastritis-inducing bacteria, Helicobacterfelis (H . felis) dramatically and time dependently decreased the PLA2 activity in the glandular stomach of the mouse strain, C57BL/6, sensitive to the organism, which appeared to be related to a decrease in the percentage of sPLA2-IB present in the active form . This bacterial-induced reduction in PLA2 activity was not observed in BALB/c mice that fail to develop gastritis in response to H . felis infection . C57BL/6 mice do not, while BALB/c mice express, the PLA2-II enzyme . The H . felis-induced reduction in sPLA2-IB activity may weaken the gastric barrier by reducing the local concentration of arachidonic and linoleic acid, liberated from membrane phospholipids, the major precursors of 'cytoprotective' prostaglandins . Data presented here suggest that both sPLA2-IB and sPLA2-II enzymes may contribute to the gastric response to Helicobacter infection. Surgery, 2001 Aug, 130(2), 396 - 402 Determinants of blood loss during primary burn excision; Hart DW et al.; BACKGROUND: Excisional therapy for burn wounds is frequently associated with large operative blood losses . Our objective was to identify patient and operative factors that affect surgical blood loss and determine strategies to minimize hemorrhage . METHODS: Data from 92 consecutive pediatric patients with severe burns (>40% total body surface area) were evaluated . Patient demographics, burn characteristics, operative factors, and clinical course variables were correlated with blood loss . Blood loss at the time of initial total burn excision was determined by a standardized, previously validated method . Data were analyzed sequentially and cumulatively through univariate and cross-sectional multivariate linear regression . RESULTS: Demographic factors that correlated with increased blood loss were older age, male sex, and larger body size . Area of full-thickness (third-degree) burn correlated with blood loss, whereas total burn size did not . High wound bacteria counts (derived from quantitative tissue cultures), total wound area excised, and operative time were the strongest predictors of the volume of operative hemorrhage . Blood loss increased with delay to primary burn excision at a maximum at 5 to 12 days after burn injury . CONCLUSIONS: Early definitive surgical therapy before extensive bacterial colonization and rapid operative excision is a strategy that may decrease operative hemorrhage and transfusion requirements during burn surgical procedures. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2001 Aug, 92(2), 166 - 9 The relationship between gastric-oral Helicobacter pylori and oral hygiene in patients with vitamin B12-deficiency anemia; Avcu N et al.; OBJECTIVE: The aim of this study was to determine whether a relationship exists between gastric and oral Helicobacter pylori and oral hygiene in patients with vitamin B12 deficiency . STUDY DESIGN: One hundred eight patients with vitamin B12 deficiency who were H pylori -positive in their gastric mucosa were enrolled in the study . These patients were divided into 3 groups determined by Oral Hygiene Index (OHI) scores of good, fair, or poor . H pylori was detected in the dental plaque with camphylobacter-like organism test gels . All patients were treated with a combination regimen to eradicate H pylori . RESULTS: H pylori positivity in dental plaque was correlated with OHI scores; the positivity was 28.5%, 90.2%, or 100% in patients with good, fair, or poor OHI scores, respectively . The eradication of H pylori was associated with recovery from anemia and increased serum vitamin B12 level (P <.0001 and P <.0001) . The patients with poor OHI scores had the most frequent gastric recurrence of H pylori (58.3%) compared with those with fair OHI scores (41.2%) and good OHI scores (4.8%) . CONCLUSIONS: H pylori seems to be an etiologic factor in vitamin B12 deficiency, since anemia was cured and the level of vitamin B12 in the serum increased as a result of its eradication . However, eradication of H pylori from gastric mucosa alone is not enough to prevent gastric recurrence of the bacteria . Proper oral hygiene must be established to eliminate H pylori in dental plaque . Therefore, we suggest that control of H pylori in dental plaque is necessary to control recurrence of H pylori. J Biol Chem, 2001 Oct 19, 276(42), 39492 - 500 Epub 2001 Aug 14. The Hemophilus influenzae Hap autotransporter is a chymotrypsin clan serine protease and undergoes autoproteolysis via an intermolecular mechanism; Fink DL et al.; The Hemophilus influenzae Hap adhesin is an autotransporter protein that undergoes an autoproteolytic cleavage event resulting in extracellular release of the adhesin domain (Hap(s)) from the membrane-associated translocator domain (Hap(beta)) . Hap autoproteolysis is mediated by Ser(243) and occurs at LN1036-7 and to a lesser extent at more COOH-terminal alternate sites . In the present study, we sought to further define the mechanism of Hap autoproteolysis . Site-directed mutagenesis of residues His(98) and Asp(140) identified a catalytic triad conserved among a subfamily of autotransporters and reminiscent of the SA (chymotrypsin) clan of serine proteases . Amino-terminal amino acid sequencing of histidine-tagged Hap(beta) species and site-directed mutagenesis established that autoproteolysis occurs at LT1046-7, FA1077-8, and FS1067-8, revealing a consensus target sequence for cleavage that consists of ((Q/R)(A/S)X(L/F)) at the P4 through P1 positions . Examination of a recombinant strain co-expressing a Hap derivative lacking all cleavage sites (HapDelta1036-99) and a Hap derivative lacking proteolytic activity (HapS243A) demonstrated that autoproteolysis occurs by an intermolecular mechanism . Kinetic analysis of Hap autoproteolysis in bacteria expressing Hap under control of an inducible promoter demonstrated that autoproteolysis increases as the density of Hap precursor in the outer membrane increases, confirming intermolecular cleavage and suggesting a novel mechanism for regulation of bacterial adherence and microcolony formation. Oper Dent, 2001 Jul-Aug, 26(4), 336 - 42 Pulpal inflammatory responses following non-carious class V restorations; About I et al.; The effects of inflammatory activity following surgical intervention can injure pulp tissues; in severe cases it can lead to pulpal complications . With this article, the authors report on the effects of cavity preparation and restoration events and how they can interact together to reduce or increase the severity of pulpal inflammatory activity in 202 restored Class V cavities . Although some inflammatory activity was observed in the absence of bacteria, the severity of pulpal inflammatory activity was increased when cavity restorations became infected . Zinc oxide eugenol and resin-modified glass ionomer cement prevented bacterial microleakage in cavity restorations, with no severe inflammatory activity observed with these materials . Bacteria were observed in cavities restored with enamel bonding resin and adhesive bonded composites and were associated with severe grades of inflammatory activity . The cavity remaining dentin thickness influenced the grade of inflammatory activity . In the absence of infection, the grade of inflammatory activity decreased after 20 weeks post-operatively . In the presence of infection, the grade of pulpal inflammation remained stable until a minimum of 30 weeks had elapsed. Crit Rev Toxicol, 2001 Jul, 31(4-5), 681 - 95 Radiation hormesis: data and interpretations; Upton AC; Although the biological effects of large doses of ionizing radiation are predominantly harmful, low-to-intermediate doses have been observed to enhance growth and survival, augment the immune response, and increase resistance to the mutagenic and clastogenic effects of further irradiation in plants, bacteria, insects, and mammals . The existence of these stimulatory, or "adaptive", responses implies that the dose-response relationships for genetic and carcinogenic effects of radiation may be similarly biphasic, or hormetic, in nature, a possibility with far-reaching implications for radiation protection . As yet, however, the extent to which such responses may actually reduce the risks attributable to low-level irradiation remains to be determined, pending further elucidation of the relevant dose-response relationships and the apparent lack of responsiveness in some individuals . Therefore, further research is needed to resolve this question. Antimicrob Agents Chemother, 2001 Sep, 45(9), 2517 - 23 Isolation of rat dihydrofolate reductase gene and characterization of recombinant enzyme; Wang Y et al.; While assays of many antifolate inhibitors for dihydrofolate reductase (DHFR) have been performed using rat DHFR as a target, neither the sequence nor the structure of rat DHFR is known . Here, we report the isolation of the rat DHFR gene through screening of a rat liver cDNA library . The rat liver DHFR gene has an open reading frame of 561 bp encoding a protein of 187 amino acids . Comparisons of the rat enzyme with those from other species indicate a high level of conservation at the primary sequence level and more so for the amino acid residues comprising the active site of the enzyme . Expression of the rat DHFR gene in bacteria produced a recombinant protein with high enzymatic activity . The recombinant protein also paralleled the human enzyme with respect to the inhibition by most of the antifolates tested with PT652 and PT653 showing a reversal in their patterns . Our results indicated that rat DHFR can be used as a model to study antifolate compounds as potential drug candidates . However, variations between rat and human DHFR enzymes, coupled with unique features in the inhibitors, could lead to the observed differences in enzyme sensitivity and selectivity. Curr Opin Neurobiol, 2001 Aug, 11(4), 462 - 7 Magnetite-based magnetoreception; Kirschvink JL et al.; Orientation, navigation, and homing are critical traits expressed by organisms ranging from bacteria through higher vertebrates . Sensory systems that aid such behavior have provided key selective advantages to these groups over the past 4 billion years, and are highly evolved; magnetoreception is no exception . Across many species and groups of organisms, compelling evidence exists that the physical basis of this response is tiny crystals of single-domain magnetite (Fe3O4) . It is the opinion of the authors that all magnetic field sensitivity in living organisms, including elasmobranch fishes, is the result of a highly evolved, finely-tuned sensory system based on single-domain, ferromagnetic crystals. Cell Mol Biol (Noisy-le-grand), 2001 Jun, 47(4), 689 - 94 Breach of IL-12 monopoly in the initiation of type 1 immunity to intracellular infections: IL-12 is not required; Xing Z; IL-12 is believed to play an important role in type 1 T-cell differentiation and type 1 cytokine IFN-gamma release by T- and NK-cells and macrophages in host defense against intracellular infections by bacteria, parasites, fungi and viruses . However, recent studies by us and others have provided unequivocal evidence that while IL- 12 is critically required for the development of type 1 immunity to the majority of intracellular bacterial, parasitic and fungal infections, it is not required for anti-viral type 1 immune responses . These findings have provoked our re-thinking about the role of IL-12 in type 1 immunity and the search for additional cytokines capable of initiating anti-viral type 1 immunity . We hypothesize that there exist multiple cytokines including IL-12 which play a redundant role in the initiation of type 1 immunity against viral infection . These cytokines are likely released from not only antigen-presenting macrophages/dendritic cells but many other cell types, which suits the mode of viral infection . The existence of multiple factors capable of driving type 1 immunity endows the host with additional safeguards to cope with prevalent viral foes. Kurume Med J, 2001, 48(2), 117 - 27 Early diagnosis and treatment of pulmonary opportunistic infection by using polymerase chain reaction and beta-glucan in patients with hematological neoplasms; Jojima H; The early diagnosis of 58 patients with hematological neoplasms accompanied by severe pulmonary infections of Pneumocystis carini (Pc), or Cytomegalovirus (CMV) pneumonia was made by polymerase chain reaction (PCR) using sputum samples, and of pulmonary mycosis by measuring blood beta-glucan levels by a Limulus test . The effectiveness of early treatment for opportunistic infection based on these early stage diagnosis was evaluated and the results of pathological analyses of the lung at autopsy were analyzed . PCR identified Pc pneumonia in 7 of the total 58 patients (12.1%), and early treatment was effective in all 7 patients (100%) . PCR identified CMV pneumonia in 5 patients (8.6%), and early treatment was effective in 2 of the 5 patients . The level of beta-glucan confirmed mycotic pneumonia in 9 of these 58 patients (15.5%), and early treatment was effective in 7 of these (66.7%) . These findings indicate that PCR and the beta-glucan method effectively enabled clinicians to diagnose pulmonary opportunistic infection in the early stage in 21 of the 58 patients (36.2%), and that early treatment was effective in 16 of the 21 patients (76.2%) . The results of the pathological analyses of the lung at autopsy were: pulmonary tumor cell infiltration in a total of 5 patients (2 with ATL, 2 with NAE and 1 with AML); infection in a total of 6 patients (2 with ML and 4 with ATL); and diffused alveolar damage in a total of 4 patients (2 with ML, 1 with ATL and 1 with AML) . CMV infection was confirmed in a total of 5 patients (2 with ML and 3 with ATL), and mucormycosis in a total of 2 patients (1 with ML and 1 with ATL) . Despite these findings, Pc and other fungi or bacteria were not detected . Early diagnosis and treatment by the present PCR and beta-glucan method were useful, but the underlying disease and its disease state influenced the clinical outcomes of patients with terminal pulmonary infection caused by CMV or mucor, suggesting that prevention and early diagnostic measures for these infections remain to be established. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(6), 1113 - 28 Biodesulphurization of coal: mechanism and rate limiting factors; Malik A et al.; The pyrite sulphur removal from coal by Thiobacillus ferrooxidans was studied in batch reactor . A combination of SEM, IR and XRD was used to study the presence of superficial phases and the changes in solid surface during biodesulphurization . Biodesulphurization was found to be a three-step process . In the first step (0-4 days), direct oxidation of pyrite by bacteria brought about 28% pyritic sulphur removal . Both direct and indirect oxidation contributed to the second step (4-10 days) resulting in 51% pyrite removal . The deposition of elemental sulphur, jarosite and ferric sulphate precipitates in the third step reduced the pyrite availability and ferric iron concentration in the leachate and brought the process of biodesulphurization to an end.
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