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dose-dependent activation of microglial cells by toll-like receptor agonists alone and in combination.microglial cells express toll-like receptors (tlrs) recognising exogenous and endogenous ligands. upon stimulation with agonists of tlr2, tlr4, and tlr9, nitric oxide (no) and tumor necrosis factor-alpha (tnf-alpha) were released by primary mouse microglial cell cultures. endotoxin was most potent in stimulating microglia followed by pneumolysin, cytosine-guanosine (cpg) oligodesoxynucleotide (odn), and tripalmitoyl-s-glyceryl-cysteine. maximum stimulation of tlr2, tlr4, and tlr9 resulted in app ...200415652406
[monosaccharide composition of some mollicutes].when studying a small group of mollicutes which interact in different way with the host organism (mycoplasma fermentans pg18--is considered a commensal of the human urogenital tract, and sometimes manifests as aids cofactor, acholeplasma laidlawii pg8 is saprophytic but it is connected with various pathologies in human organism, a. laidlawii var. granulum 118--agent of the yellow of cereals--palegreen dwarfness) the author has found the carbohydrate composition of their cell surface. glycocalix ...200415765866
structural features of glycosyltransferases synthesizing major bilayer and nonbilayer-prone membrane lipids in acholeplasma laidlawii and streptococcus pneumoniae.in membranes of acholeplasma laidlawii two consecutively acting glucosyltransferases, the (i) alpha-monoglucosyldiacylglycerol (mglcdag) synthase (almgs) (ec ) and the (ii) alpha-diglucosyl-dag (dglcdag) synthase (aldgs) (ec ), are involved in maintaining (i) a certain anionic lipid surface charge density and (ii) constant nonbilayer/bilayer conditions (curvature packing stress), respectively. cloning of the aldgs gene revealed related uncharacterized sequence analogs especially in several gram- ...200312464611
fourier transform infrared spectroscopic study of the interactions of a strongly antimicrobial but weakly hemolytic analogue of gramicidin s with lipid micelles and lipid bilayer membranes.cyclo[vkldkvdyplkvkldyp] (gs14dk(4)), a synthetic tetradecameric ring-size analogue of the naturally occurring antimicrobial peptide gramicidin s (gs), retains the strong antimicrobial activity of gs but is 15-20 times less hemolytic. to characterize its interaction with lipid membranes and to understand the molecular basis of its capacity to lyse bacterial cells, in preference to erythrocytes, we have investigated the interactions of gs14dk(4) with detergent micelles and with lipid bilayer mode ...200312525171
effect of independent variations in fatty acid structure and chain length on lipid polar headgroup composition in acholeplasma laidlawii b membranes: regulation of lamellar/nonlamellar phase propensity.we have studied the biosynthetic regulation of the membrane lipid polar headgroup distribution in acholeplasma laidlawii b cells made fatty acid auxotrophic by growth in the presence of the biotin-binding agent avidin to test whether this organism has the ability to coherently regulate the lamellar/nonlamellar phase propensity of its membrane lipids. the addition of various single normal growth-supporting exogenous fatty acids to such cell cultures produces fatty acid-homogeneous cells in which ...200312564934
lateral organization in acholeplasma laidlawii lipid bilayer models containing endogenous pyrene probes.in membranes of the small prokaryote acholeplasma laidlawii bilayer- and nonbilayer-prone glycolipids are major species, similar to chloroplast membranes. enzymes of the glucolipid pathway keep certain important packing properties of the bilayer in vivo, visualized especially as a monolayer curvature stress ('spontaneous curvature'). two key enzymes depend in a cooperative fashion on substantial amounts of the endogenous anionic lipid phosphatidylglycerol (pg) for activity. the lateral organizat ...200312694183
observation of co(2) in fourier transform infrared spectral measurements of living acholeplasma laidlawii cells.in monitoring the time course of conformational disorder by fourier transform infrared spectroscopy for intact acholeplasma laidlawii cells grown at 37 degrees c on binary fatty acid mixtures containing oleic acid and for cells grown on pure palmitic acid, an absorption band at 2343 cm(-1) was observed. the band intensity was found to increase with time. this band was not observed in the spectra for isolated membranes. it is suggested that the 2343 cm(-1) band is due to co(2) dissolved in water, ...200312736075
irreversible binding and activity control of the 1,2-diacylglycerol 3-glucosyltransferase from acholeplasma laidlawii at an anionic lipid bilayer surface.1,2-diacylglycerol 3-glucosyltransferase is associated with the membrane surface catalyzing the synthesis of the major nonbilayer-prone lipid alpha-monoglucosyl diacylglycerol (mglcdag) from 1,2-dag in the cell wall-less acholeplasma laidlawii. phosphatidylglycerol (pg), but not neutral or zwitterionic lipids, seems to be essential for an active conformation and function of the enzyme. surface plasmon resonance analysis was employed to study association of the enzyme with lipid bilayers. binding ...200312911309
colistin sulfate as a suitable substitute of thallium acetate in culture media intended for mycoplasma detection and culture.thallium acetate in concentrations of 500 to 1000 mg/l is tolerated in the culture by the most mollicutes of the orders mycoplasmatales and acholeplasmatales and by this reason it is added in the culture media as a selective element for the detection and propagation of mycoplasmas and acholeplasmas. because of the high toxicity of thallium acetate and its accumulation in the environment, thallium acetate is not biodegradable, an alternative was searched. the results and analysis of tests with ni ...200312935803
antiserum raised against gyrase a of acholeplasma laidlawii reacts with phytoplasma proteins.part of the gyrase a gene (gyra) of acholeplasma laidlawii was cloned and incorporated directly downstream from a 6 x his tag segment of the pqe expression vector. the 23-kda fusion protein was expressed as a 6 x his-tagged protein in escherichia coli. the fusion protein was purified and used as an antigen for rabbit immunization. western immunoblot analysis revealed that the antiserum raised against the gyrase a fragment had a specific affinity for a 108-kda protein of a. laidlawii and cross-re ...200211814658
comparative pcr analysis for detection of mycoplasma infections in continuous cell lines.mycoplasma contamination of cell lines is one of the major problems in cell culturing. about 15-35% of all cell lines are infected with a limited number of mycoplasma species of predominantly human, swine, or bovine origin. we examined the mycoplasma contamination status in 495 cell cultures by polymerase chain reaction (pcr) assay, microbiological culture method, and deoxyribonucleic acid-ribonucleic acid (dna-rna) hybridization, and in 103 cell cultures by pcr and dna-rna hybridization, in ord ...200211928999
another cut for lysine trna: application of the hyperprocessing reaction reveals another stabilization strategy in metazoan lysine trnas.recently, we revealed that the cloverleaf structure of some eukaryotic trnas is not always stable in vitro, and the denatured structures of these trnas are sometimes detected in bacterial rnase p reactions. we have designated the unusual internal cleavage reaction of these trnas as hyperprocessing. we have developed this hyperprocessing strategy as a useful tool for examining the stability of the trna cloverleaf structure. there are some common features in such unstable, hyperprocessible trnas, ...200212038980
the biosynthetic incorporation of short-chain linear saturated fatty acids by acholeplasma laidlawii b may suppress cell growth by perturbing membrane lipid polar headgroup distribution.acholeplasma laidlawii b cells made fatty acid auxotrophic by growth in the presence of the biotin-binding agent avidin grow increasingly poorly at 37 degrees c when supplemented with single exogenous linear saturated fatty acids of decreasing hydrocarbon chain length. interestingly, this progressive decrease in growth yields with decreasing hydrocarbon chain length is not observed when cells are cultured in the presence of other classes of exogenous fatty acids. moreover, normal growth is obser ...200212093284
performance of a novel viresolve nfr virus filter.mammalian cell-expressed therapeutic proteins are particularly vulnerable to contamination by endogenous retrovirus-like particles (rvlps). the viresolve nfr filter was designed to meet the critical requirement of manufacturing a safe and virus-free therapeutic by retaining rvlps by a minimum of six log reduction value (lrv). the nfr designation refers to retrovirus removal in a normal flow format. to qualify the product, we tested two model viruses: the 78 nm diameter phi6 bacteriophage and the ...200212153313
regulation of lipid composition in acholeplasma laidlawii and escherichia coli membranes: nmr studies of lipid lateral diffusion at different growth temperatures.lipid lateral diffusion coefficients have been directly determined by pulsed field gradient nmr spectroscopy on macroscopically aligned, fully hydrated lamellar phases containing dimyristoylphosphatidylcholine and total lipid extracts from acholeplasma laidlawii and escherichia coli. the temperature dependence of the diffusion coefficient was of the arrhenius type in the temperature interval studied. the sharp increase in the diffusion coefficient at the growth temperature of e. coli obtained by ...200212234195
differential inhibition of mollicute growth: an approach to development of selective media for specific mollicutes.the energy-generating pathways of mycoplasma spp. are diverse. thus, it was predicted that the ability of inhibitors of these pathways to block growth would vary among species. this prediction was tested with 14 mycoplasma species and potential inhibitors. the greatest differentiation among test species was obtained using fluoride, iodoacetate (iaa), beta-fluoropyruvate (fp), cibacron blue (cb), l-citrulline, and carbonyl cyanide m-chlorophenylhydrazone. a range of other potential inhibitors, in ...200212324351
the effects of ring-size analogs of the antimicrobial peptide gramicidin s on phospholipid bilayer model membranes and on the growth of acholeplasma laidlawii b.we have examined the effects of three ring-size analogs of the cyclic beta-sheet antimicrobial peptide gramicidin s (gs) on the thermotropic phase behavior and permeability of phospholipid model membranes and on the growth of the cell wall-less gram-positive bacteria acholeplasma laidlawii b. these three analogs have ring sizes of 10 (gs10), 12 (gs12) or 14 (gs14) amino acids, respectively. our high-sensitivity differential scanning calorimetric studies indicate that all three of these gs analog ...200212444980
opposing roles of activator protein-1 and ccaat/enhancer binding protein beta in the regulation of inducible granulysin gene expression in a human monocytic cell line, thp-1.we previously reported that inducible granulysin gene expression in a human monocytic cell line, thp-1 is dominantly dependent on transcription factor activator protein-1 (ap-1). here, we further examined the precise regulatory mechanisms underlying granulysin gene expression using thp-1 cells treated with acholeplasma laidlawii. transfection of reporter gene constructs into thp-1 cells indicated that the presence of a positive regulatory element(s) is located from -329 to -85 base pairs, contai ...200212460196
alternative to fluorescence assays to monitor fusion between acholeplasma laidlawii cells and liposomes.to develop a new technique as an alternative to the fluorescence assays and electron microscopy for the purpose of monitoring the cell-liposome fusion.200212460438
[cytotoxic activity of melittin expressed by recombinant vectors in acholeplasma laidlawii and mycoplasma hominis cells].recombinant plasmids containing the mellitin gene under the control of the lac and the tetm gene promoters were used for studying cytotoxic activity of mellitin in cells of mollicutes (mycoplasmas) and escherichia coli. after transformation of acholeplasma laidlawii and mycoplasma hominis cells with recombinant plasmid dnas by electroporation, cell growth was suppressed. the expression of the mellitin gene in a. laidlawii and m. hominis cells was demonstrated using the reverse transcription poly ...200111234424
sequence properties of the 1,2-diacylglycerol 3-glucosyltransferase from acholeplasma laidlawii membranes. recognition of a large group of lipid glycosyltransferases in eubacteria and archaea.synthesis of the nonbilayer-prone alpha-monoglucosyldiacylglycerol (mglcdag) is crucial for bilayer packing properties and the lipid surface charge density in the membrane of acholeplasma laidlawii. the gene for the responsible, membrane-bound glucosyltransferase (almgs) (ec ) was sequenced and functionally cloned in escherichia coli, yielding mglcdag in the recombinants. similar amino acid sequences were encoded in the genomes of several gram-positive bacteria (especially pathogens), thermophil ...200111294844
retention of water-borne bacteria by membrane filters. part iii: bacterial challenge tests on 0.1 micron rated filters.clear performance differences were observed between different 0.1 micron rated filters in terms of their microbial removal efficiency when challenged with naturally occurring waterborne bacteria from a water source. penetration occurred with three 0.1 micron rated "sterilizing grade" filter types tested, from three different filter manufacturers, that did not have a specific high titer reduction claim for acholeplasma laidlawii. bacteria shown to penetrate these 0.1 micron rated filters were qui ...200111310317
effects of synthetic cecropin analogs on in vitro growth of acholeplasma laidlawii.four synthetic peptides (peptidyl mims; demeter biotechnologies, inc.) were evaluated for their in vitro activity against acholeplasma laidlawii. fifty percent effective concentration values ranged from 1 to 15 microm. three of these compounds are more lethal than cecropin b against a. laidlawii.200111353647
species-specific pcr for identification of common contaminant mollicutes in cell culture.mycoplasma arginini, m. fermentans, m. hyorhinis, m. orale, and acholeplasma laidlawii are the members of the class mollicutes most commonly found in contaminated cell cultures. previous studies have shown that the published pcr primer pairs designed to detect mollicutes in cell cultures are not entirely specific. the 16s rrna gene, the 16s-23s rrna intergenic spacer region, and the 5' end of the 23s rrna gene, as a whole, are promising targets for design of mollicute species-specific primer pai ...200111425741
comparative studies of the persistence of animal mycoplasmas under different environmental conditions.a comparison of the persistence of mycoplasmas in animals was carried out. when inoculated into liquid media, strains of mycoplasma bovis, m. arginini, acholeplasma laidlawii, and a. axanthum persisted for 59-185 days post-inoculation. the survival periods were not significantly influenced by temperature (4, 30, 37 degrees c, and room temperature). the survival periods for m. bovigenitalium, m. gallisepticum, m. bovirhinis, and m. gateae ranged from <7 to 185 days depending on medium components ...200111470544
[changes in acholeplasma laidlawii plasma membrane functions during development of resistance to ciprofloxacin and tetracycline].the role of transport activity of acholeplasma laidlawii plasmatic membrane in the development of resistance to ciprofloxacin and tetracycline was investigated. it was shown that one of the important steps of resistance development in acholeplasms is a complex of adaptation metabolic reactions providing limited antibiotic accumulation by the cells. in the case of ciprofloxacin resistance metabolism changes concerning transport systems took place before mutations in target genes. development of t ...200111548275
chemical analysis of lipid-modified membrane proteins in acholeplasma laidlawii.the lipid modification of membrane proteins was investigated in acholeplasma laidlawii by metabolic labeling and by chemical analysis. a s-glycerylcysteine residue was identified from membrane proteins and we reported the strong preference for saturated acyl chains into the lipid modification. differential release of fatty acids revealed a ratio [(o-ester- + amide-bound acyl chains)/o-ester-linked chains] close to 1.1 which suggests the involvement of only two o-ester linked fatty acids in the a ...200111685510
acholeplasma laidlawii up-regulates granulysin gene expression via transcription factor activator protein-1 in a human monocytic cell line, thp-1.an antimicrobial protein granulysin is constitutively expressed in cytotoxic t lymphocytes (ctl) and natural killer (nk) cells. however, little is known about the precise regulatory mechanisms underlying granulysin gene expression. in this study, we examined the regulatory mechanisms underlying granulysin gene expression using a human monocytic cell line, thp-1, treated with acholeplasma laidlawii. the level of granulysin mrna expression in thp-1 cells was significantly augmented in response to ...200111722647
novel deoxynucleoside-phosphorylating enzymes in mycoplasmas: evidence for efficient utilization of deoxynucleosides.mycoplasmas are unable to synthesize purine and pyrimidine bases de novo. therefore, salvage of existing nucleosides and bases is essential for their survival. four mycoplasma species were studied with regard to their ability to phosphorylate deoxynucleosides. high levels of thymidine kinase (tk), deoxycytidine kinase (dck), deoxyguanosine kinase (dgk) and deoxyadenosine kinase (dak) activities were detected in extracts from mycoplasma pneumoniae, mycoplasma mycoides subsp. mycoides sc (m. mymys ...200111737647
method for qualifying microbial removal performance of 0.1 micron rated filters. part i: characterization of water isolates for potential use as standard challenge organisms to qualify 0.1 micron rated filters.although 0.1 microm rated filters intended for pharmaceutical sterilization applications have been commercially available for at least 15 years, there is no industry-wide standard for qualifying the microbial removal performance of these filters. in this article, we report on the bacterial challenge methodology used to screen four bacterial species for potential utility as a standard challenge organism to qualify 0.1 microm rated filters. these isolates were, in their natural state, demonstrated ...200111766822
method for qualifying microbial removal performance of 0.1 micron rated filters. part ii: preliminary characterization of hydrogenophaga (formerly pseudomonas) pseudoflava for use as a standard challenge organism to qualify 0.1 micron rated filters.in this article, we report on the preliminary characterization of hydrogenophaga (formerly pseudomonas) pseudoflava for potential use as a standard challenge organism to qualify 0.1 microm rated filters. filter-cloned h. pseudoflava (atcc 700892) was easily cultured in a low nutrient broth (r2a broth) under standard laboratory conditions, reaching high titers of 10(8)-10(9) cfu/ml within 48-65 hours of incubation at 25+/-5 degrees c. under these conditions, h. pseudoflava is a rod-shaped bacteri ...200111766823
a polymerase chain reaction based method for detecting mycoplasma/acholeplasma contaminants in cell culture.a detection system that utilizes a primer mixture in a nested polymerase chain reaction for detecting mycoplasma contaminants in cell cultures is described. primers were designed to amplify the spacer regions between the 16s and 23s ribosomal rna genes of mycoplasma and acholeplasma. this detection system was able to detect 20-180 colony forming units per milliliter of sample. eight commonly encountered mycoplasma and acholeplasma contaminants, which include mycoplasma (m.) arginini, m. fermenta ...200010576701
common elements of spiroplasma plectroviruses revealed by nucleotide sequence of svts2.dna of spv1-like spiroplasma plectroviruses (rods with single-stranded circular dna) is scattered in the genome of the phytopathogen spiroplasma citri and has significant consequences for evolution of the s. citri genome. we determined the complete nucleotide sequence of svts2, a spv1-like virus of s. melliferum, a honeybee pathogen, to ascertain, by comparison with s. citri spv1 viruses (genbank u28974 and x51344), the defining features of this important group. the 6,824 nt dna contains nine or ...200010766306
effect of some psychotropic drugs and a barbiturate on mycoplasmas.the inhibitory effect of selected membrane stabilisers on mycoplasma pneumoniae, m. hominis and ureaplasma urealyticum was investigated in vitro. the phenothiazine chlorpromazine (cpz) and the barbiturate thiopental (leopental(r)) as well as the stereo-isomeric thioxanthene derivatives; cis(z)-clopenthixol (zu-clopenthixol(r))/ trans (e)-clopenthixol and cis (z)-chlorprothixen (truxal(r))/trans(e)-chlorprothixen, all have antimycoplasmal effect in the range 3.9-312 mg/l, measured as growth inhib ...200010773494
[analysis of genes, coding for dna gyrase from the mycoplasma acholeplasma laidlawii pg-8b]. 200010779957
development and qualification of a novel virus removal filter for cell culture applications.commercial bioreactors employing mammalian cell cultures to express biological or pharmaceutical products can become contaminated with adventitious viruses. the high expense of such a contamination can be reduced by passing all gases and fluids feeding the bioreactor through virus inactivation or removal steps, which act as viral barriers around the bioreactor. a novel virus barrier filter has been developed for removing viruses from serum-free cell culture media. this filter removes the 20 nm m ...200010835245
[the participation of the transport-barrier functions of the plasma membrane in the development of fluoroquinolone (ciprofloxacin) resistance in acholeplasma laidlawii].the role of transport activity of acholeplasma laidlawii plasmatic membrane in the development of resistance to ciprofloxacin was investigated. it was shown that ethidium bromide used as fluoroquinolone analogue in plasmatic membrane efflux pump was accumulated in ciprofloxacin-resistant cells in much less amount. it was estimated that ethidium bromide efflux depended on temperature, glucose and transmembrane electro-chemical proton potential. inhibitors of efflux systems--reserpine and verapami ...200010862349
[role of mutations in the a-subunit of acholeplasma laidlawii pg-8b topoisomerase iv in formation of resistance to fluoroquinolones].nucleotide sequence of acholeplasma laidlawii genome site pg-8b (1000 n.p.), containing topoisomerase iv subunit genes (pare and parc), has been determined. sequenced genome site contains a gene fragment coding for the c-terminal region of pare and gene fragment coding for n-terminal region of parc. topoisomerase iv subunite genes in a. laidlawii genome are situated near each other and overlapping by 4 nucleotides. selection in liquid nutrient medium with ascending antibiotic concentrations resu ...200010876765
binding of glycoglycerolipid derived from membranes of acholeplasma laidlawii pg8 and synthetic analogues to lymphoid cells.a component that binds to human lymphoid cells was isolated from the membranes of acholeplasma laidlawii pg8. the component was extracted using the bligh-dyer method and purified using a silica-gel column and tlc. the active component was identified as 3-o:-[2'-o-(alpha-d-glucopyranosyl)- 6'-o-acyl-alpha-d-glucopyranosyl]-1,2-di-o- acyl-sn-glycerol (gagdg) using (1)h- and (13)c-nmr and gc-ms. the compositions of the major saturated fatty acids were nc (14) (17.8%), isoc(14) (10.7%) and nc (16) ( ...200010974119
x-ray studies on the interaction of the antimicrobial peptide gramicidin s with microbial lipid extracts: evidence for cubic phase formation.we have investigated the effect of the interaction of the antimicrobial peptide gramicidin s (gs) on the thermotropic phase behavior of model lipid bilayer membranes generated from the total membrane lipids of acholeplasma laidlawii b and escherichia coli. the a. laidlawii b membrane lipids consist primarily of neutral glycolipids and anionic phospholipids, while the e. coli inner membrane lipids consist exclusively of zwitterionic and anionic phospholipids. we show that the addition of gs at a ...200011018666
alpha-methylene ordering of acyl chains differs in glucolipids and phosphatidylglycerol from acholeplasma laidlawii membranes: (2)h-nmr quadrupole splittings from individual lipids in mixed bilayers.a acholeplasma laidlawii strain a-ef22 was grown in a medium supplemented with alpha-deuterated oleic acid. phosphatidylglycerol (pg), the glucolipids monoglucosyldiacylglycerol (mglcdag), diglucosyldiacylglycerol (dglcdag) and monoacyldiglucosyldiacylglycerol, and the phosphoglucolipid glycerophosphoryldiglucosyldiacylglycerol (gpdglcdag) were purified, and the phase behaviour and molecular ordering for the individual lipids, as well as for mixtures of the lipids, were studied by (2)h-, (31)p-n ...200011018677
[effect of mycoplasma contamination of a human cervical carcinoma cell line m hela clone 11 on karyotypic variability].the karyotypic variability has been investigated for an immortalized human epithelioid cervix carcinoma cell line m hela clone 11, cultivated for 15-60 days after contamination with acholeplasma laidlawii a, strain pg-8, and for 30 days after contamination with mycoplasma arginini r-16. the character of cell distribution for chromosome number changes in contaminated cells significantly, as compared to the control. so, the frequency of cells with the modal number of chromosomes being equal to 50 ...200011033866
the nonbilayer/bilayer lipid balance in membranes. regulatory enzyme in acholeplasma laidlawii is stimulated by metabolic phosphates, activator phospholipids, and double-stranded dna.in membranes of acholeplasma laidlawii a single glucosyltransferase step between the major, nonbilayer-prone monoglucosyl-diacylglycerol (mglcdag) and the bilayer-forming diglucosyl-diacylglycerol (dglcdag) is important for maintenance of lipid phase equilibria and curvature packing stress. this dglcdag synthase is activated in a cooperative fashion by phosphatidylglycerol (pg), but in vivo pg amounts are not enough for efficient dglcdag synthesis. in vitro, phospholipids with an sn-glycero-3-ph ...200010734070
[the effect of mycoplasmal contamination of human embryonic lung cell line mrc-5 on the karyotypic variability].karyotypic variability has been investigated for nonimmortalized human embryonic lung cell line mrc-5, cultivated with acholeplasma laidlawii strain pg-8 for 15-45 days. the character of cell distribution for chromosome number did not change during this time. in all investigated variants the number of polyploid cells increased considerably with the lengthening of the term after decryoconservation. the number of chromosomal aberrations in 15-45 days contaminated cells increased significantly as c ...200010752125
range of phytoplasma concentrations in various plant hosts as determined by competitive polymerase chain reaction.abstract for competitive polymerase chain reaction (pcr), an internal standard dna template was developed that consisted of a highly conserved, internally deleted 16s rdna fragment of an aster yellows phytoplasma. the internal standard was calibrated using a quantified culture of acholeplasma laidlawii. serial dilutions of the internal standard and fixed amounts of target templates from infected plants were coamplified with the same primers, and the products obtained were quantified using an enz ...200018944479
application of membrane filtration for removal of diminutive bioburden organisms in pharmaceutical products and processes.in this report, we present results of a recent investigation in our laboratories demonstrated the effect of process conditions and/or drug product composition on the ability of 0.2 micron and 0.22 micron sterilizing grade filters to fully retain ralstonia (formerly burkholderia, formerly pseudomonas) pickettii. r. pickettii is a opportunistic pathogen widely distributed in nature as well as clinical specimens and there have been several reports of nosocomial infections due to intrinsic manufactu ...199910754712
[the study of quantitative karyotypic variability by induction of chromosomal instability in cultured cells of the indian muntjac skin fibroblasts].the influence of mycoplasmal contamination and somatic cell hybridization on the character of karyotypic variability in cell cultures of indian muntjac skin fibroblasts has been investigated. mycoplasma arginini and acholeplasma laidlawii, used as factors inducing chromosomal instability, do not break the main regulations peculiar to intact control. they regulations are: 1) nonrandom character of cell distribution according to the number of chromosomal deviations from msvk; 2) specific character ...199910591121
[the monosaccharide composition of the glycocalyx in mollicutes and phylogenetically related bacteria in the genus bacillus].a number of monosaccharides composing the glycocalix carbohydrates of some mollicutes (mycoplasma pneumoniae fh, m. hominis pg21, m. fermentans pg18, acholeplasma laidlawii pg8, a. laidlawii var. granulum st. 118) and phylogenetically related bacteria from the genus bacillus (bacillus cereus 89, b. cereus dm423, b. subtilis 1/2, b. licheniformis 31, b. licheniformis 49) were detected using plant lectins of definite carbohydrate specificity labelled by colloid gold. the structure of extracellular ...199910643272
zelkovamycin, a new cyclic peptide antibiotic from streptomyces sp. k96-0670. i. production, isolation and biological properties.a new antibiotic termed zelkovamycin was isolated from the fermentation broth of streptomyces sp. k96-0670 by solvent extraction, ods column chromatography and preparative hplc. zelkovamycin showed antibacterial activity against xanthomonas oryzae, acholeplasma laidlawii, pyricularia oryzae and staphylococcus aureus.199910092194
[changes in the properties of the plasma membrane of acholeplasma laidlawii under the action of tetracycline].the role of physico-chemical rearrangements in the cell plasmalemma of acholeplasma laidlawii in the development of resistance to tetracycline was investigated. the cells of a.laidlawii were shown to be tolerant to tetracycline and to preserve a rather high titre of the cells even at a concentration of the antibiotic in the inoculation medium much higher than the mic. the results of the investigation of the structural rearrangements in the plasmatic membrane of the cells grown in the presence of ...199910202551
key role of the diglucosyldiacylglycerol synthase for the nonbilayer-bilayer lipid balance of acholeplasma laidlawii membranes.in the single membrane of acholeplasma laidlawii, a specific glucosyltransferase (dglcdag synthase) synthesizes the major, bilayer-forming lipid diglucosyldiacylglycerol (dglcdag) from the preceding major, nonbilayer-prone monoglucosyldiacylglycerol (mglcdag). this is crucial for the maintenance of phase equilibria close to a potential bilayer-nonbilayer transition and a nearly constant spontaneous curvature for the membrane bilayer lipid mixture. the glucolipid pathway is also balanced against ...199910220338
[cloning and expression of the gene for the mycoplasma key division protein ftsz in escherichia coli].gene ftsz responsible for division of bacterial cells was revealed in most prokaryote groups. a 520-bp fragment of the ftsz gene was amplified on the template of a. laidlawii dna using degenerate primers. this fragment was sequenced and served as a hybridization probe for cloning of the full-sized copy of the a. laidlawii ftsz gene. the amplified fragment was cloned in a pgex3x vector and expressed in e. coli cells. polyclonal antibodies derived from the chimeric polypeptide containing a fragmen ...199910368784
molecular analysis of the cytolytic protein clya (shea) from escherichia coli.escherichia coli k-12 carries a gene for a protein denoted clya or shea that can mediate a cytolytic phenotype. the clya protein is not expressed at detectable levels in most strains of e. coli, but overproduction suitable for purification was accomplished by cloning the structural gene in an hns mutant strain. highly purified clya protein was cytotoxic to macrophage cells in culture and caused detachment and lysis of the mammalian cells. results from osmotic protection assays were consistent wi ...199910383763
characterization of acholeplasma laidlawii ftsz gene and its gene product.the ftsz gene was found among representatives of all bacterial groups. ftsz protein is an essential component of cell division ring. contraction of this cytoskeleton-like ring is believed to be the universal way of bacterial division. acholeplasma laidlawii possesses all features of the minimal mycoplasma cell and some traits of cell-wall bacteria and seems to be a promising object for study of basic principles of the bacterial division process. we cloned an a. laidlawii chromosomal fragment con ...199910448065
bactericidal/permeability-increasing protein inhibits growth of a strain of acholeplasma laidlawii and l forms of the gram-positive bacteria staphylococcus aureus and streptococcus pyogenes.bactericidal/permeability-increasing protein (bpi) inhibited growth of cell wall-deficient acholeplasma laidlawii and l forms of certain strains of staphylococcus aureus and streptococcus pyogenes. however, the same strains of s. aureus and s. pyogenes with intact cell walls were not susceptible to the growth-inhibitory effects of bpi.199910471588
occurrence of monoacyl-diglucosyl-diacyl-glycerol and monoacyl-bis-glycerophosphoryl-diglucosyl-diacyl-glycerol in membranes of acholeplasma laidlawii strain b-pg9.it is shown by thin-layer and high-performance liquid chromatography that the two membrane lipids monoacyl-diglucosyl-diacyl-glycerol (madglcdag) and monoacyl-bis-glycerophosphoryl-diglucosyl-diacyl-glycerol are synthesized by acholeplasma laidlawii strain b-pg9 when the cells are grown in two different growth media. the two lipids are also synthesized by a. laidlawii strain a-ef22 and their chemical structures have been determined previously by nmr spectroscopy. since a reversed hexagonal phase ...19989443602
synthesis, antimicrobial activity and gene structure of a novel member of the dermaseptin b family.dermaseptins are a family of cationic (lys-rich) antimicrobial peptides that are abundant in the skin secretions of the arboreal frogs phyllomedusa bicolor and p. sauvagii. in vitro, these peptides are microbicidal against a wide variety of microorganisms including gram-positive and gram-negative bacteria, yeasts, protozoa and fungi. to date, 6 dermaseptin b mature peptides, 24-34 residues long, 2 dermaseptin b cdnas and 2 gene sequences have been identified in p. bicolor. to assess dermaseptin ...19989540838
[effect of mycoplasma contamination of the human uterine leiomyosarcoma cell line sk-ut-1b on karyotype structure].the karyotypic variability has been investigated for human uterine leiomyosarcoma cell line sk-ut-1b, cultivated for 30-90 days after contamination with acholeplasma laidlawii, strain pg-8. the character of cell distribution for chromosome number gradually changes in contaminated cells, comparatively to the control, with the lengthening of the term of contamination. so, in 30 days the analysed distributions do not differ in the experimental and in the control variants, the modal number of chromo ...19989541971
lipids in total extracts from acholeplasma laidlawii a pack more closely than the individual lipids. monolayers studied at the air-water interface.pressure-area curves were obtained at 25, 35 and 45 degrees c for total lipid extracts and four individual glucolipids isolated from acholeplasma laidlawii strain a-ef22. the glucolipids are 1,2-diacyl-3-0-(alpha-d-glucopyranosyl)-sn-glycerol (mglcdag), 1,2 -diacyl-3-0-[alpha-d-glucopyranosyl-(1-->2)-0-alpha-d-glucopyranosyl] -sn-glycerol (dglcdag), 1,2-diacyl-3-0-[alpha-d-glucopyranosyl-(1-->2)-0-(6-0-acyl-alpha-d-gluco pyranosyl)]-sn-glycerol (madglcdag), and 1,2-diacyl-3-0-[glycerophosphoryl- ...19989556349
membrane permeabilisation and antimycoplasmic activity of the 18-residue peptaibols, trichorzins pa.the membrane permeabilisation properties of six linear natural 18-residue peptaibols, termed trichorzins pa, have been assessed on liposomes and on mollicutes (trivial name, mycoplasmas), a class of parasitic bacteria characterized by a small genome, the lack of a cell wall, a minute cell size, and the incorporation in their plasma membrane of exogenously supplied cholesterol. the trichorzins pa used in this study (pa ii, pa iv-vi, pa viii, and pa ix) differ between them by amino acid or amino a ...19989651487
expression of foreign genes in acholeplasma laidlawii. 19989711661
[formation of m. hominis and a. laidlawii resistance to fluoroquinolones].mycoplasma hominis and acholeplasma laidlawii cultures resistant to antibacterial fluoroquinolone drugs ciprofloxacin (cpf), ofloxacin (ofl), and lomefloxacin (lmf) were prepared by selection in liquid nutrient medium with ascending concentrations of cpf. resistant mycoplasma clones contained point mutations in the gyrase. a gene region determining quinolone resistance (qrdr gyra): m. hominis contained c-->t transition resulting in substitution of ser(83) for leu and a. laidlawii g-->a resulting ...19989819821
total lipids with short and long acyl chains from acholeplasma form nonlamellar phases.the cell-wall-less bacterium acholeplasma laidlawii a-ef22 synthesizes eight glycerolipids. some of them form lamellar phases, whereas others are able to form normal or reversed nonlamellar phases. in this study we examined the phase properties of total lipid extracts with limiting average acyl chain lengths of 15 and 19 carbon atoms. the temperature at which these extracts formed reversed hexagonal (hii) phases differed by 5-10 degreesc when the water contents were 20-30 wt%. thus the cells adj ...19989826609
production of a t-cell clone which reacts with membrane proteins of acholeplasma laidlawii.the role of cellular immunity in mycoplasma infection is not completely understood. in this study, we established mycoplasma-specific t-cell clones to evaluate cellular immunity in mycoplasma infection. we developed a t-cell clone (g-10) which was stimulated with acholeplasma laidlawii. the t-cell clone g-10, cd4+ and t-cell receptor (tcr) alpha beta- recognized the 42- and 65-kilodalton (kda) membrane proteins of a. laidlawii and responded to a. hippikon. hence, the application of mycoplasma-sp ...19979130238
phosphocholine-containing glycoglycerolipids (ggpl-i and ggpl-iii) are species-specific major immunodeterminants of mycoplasma fermentans.mycoplasma fermentans has unique glycoglycerophospholipids (ggpls: ggpl-i and ggpl-iii). previously, the structure of these lipids was determined as phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (ggpl-i) and 1"-phosphocholine-2"-aminodihydroxypropane-3"-phospho-6'-alph++ + a- glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (ggpl-iii). thin-layer chromatography (tlc) immunostaining showed that the ggpls were main lipid-antigens of the m. fermentans species. anti-m. fermentans seru ...19979168906
[the modification of the internucleotide relations of antisignature oligodeoxyribonucleotides as a means of increasing their resistance to nuclease cleavage in mollicute cells].modifications in 5'- and 3'-ends and internucleotide bondings of antisignature oligodesoxyribonucleotides have been studied for their resistance to nuclease cleavage in cells of acholeplasma laidlawii pg-8 and mycoplasma fermentans pg-18. it is shown that adding of benzylamide grouping to the 5'-end of oligonucleotides increases their half-life period in the studied mollicute cells to 15 h. s-methyl modification of 3'-end of antisignature oligonucleotides did not take essential effect on the pro ...19979172862
antisignature oligonucleotides and their analogs as inhibitors of mollicutes-cofactors of hiv.inhibition of mollicutes by synthetic oligonucleotides and their analogs complementary to specific "signature" regions of 16s rrna and corresponding sequences of ribosomal operon dna was studied. it was shown that antisignature oligonucleotides inhibited transcription in vitro for above 79% interacting specifically with ribosomal operon and non-specific with dna-dependent rna-polymerase. the inhibition efficiency depended on oligonucleotide sequence and type of modification. translation in vitro ...19979177600
nonlamellar phases induced by the interaction of gramicidin s with lipid bilayers. a possible relationship to membrane-disrupting activity.the interactions of the cyclic peptide gramicidin s (gs) with a variety of single-component lipid bilayers, and with membrane polar lipid extracts of acholeplasma laidlawii b and escherichia coli, were examined by differential scanning calorimetry (dsc), 31p-nuclear magnetic resonance (nmr) spectroscopy, and x-ray diffraction. the dsc data indicate that the effects of gs on the thermotropic phase behavior of phosphatidylcholine and phosphatidylethanolamine dispersions are compatible with those e ...19979201936
[the binding activity of diglucosyl diacylglyceride derived from membranes of acholeplasma laidlawii pg8 to lymphoid cells].a chemical component has been purified from acholeplasma laidlawii which binds to tissue culture cells, molt-4, hut-78, but not mt-4 and jurkat. the glycolipid in the membranes of a. laidlawii was extracted by bligh-dyer method. further purification of chloroform phase of bligh-dyer method was performed by silicagel column chromatography and thin layer chromatography. finally, the active component was assigned to be diglucosyl diacylglyceride by using nuclear magnetic resonance (1h, 13c). furthe ...19979248270
antibody response to mfgl-ii, a phosphocholine-containing major lipid of mycoplasma fermentans membranes.the choline-containing phosphoglycolipid, mfgl-ii, is the major polar lipid of mycoplasma fermentans pg18. anti-mfgl-ii antisera raised in rabbits using the purified mfgl-ii as an immunogen were employed in immunogold electron microscopic and immunofluorescence studies showing that mfgl-ii is uniformly distributed and exposed on the cell surface of m. fermentans cells. the specificity of the antibodies was determined by immunostaining of lipid extracts separated by thin layer chromatography. the ...19979311135
epidemiologic analysis of mycoplasma spp isolated from bulk-tank milk samples obtained from dairy herds that were members of a milk cooperative.to determine the prevalence of mycoplasma spp in herds that were members of a milk cooperative.19979343550
activating amphiphiles cause a conformational change of the 1,2-diacylglycerol 3-glucosyltransferase from acholeplasma laidlawii membranes according to proteolytic digestion.1,2-diacylglycerol 3-glucosyltransferase synthesizes the major nonbilayer-prone lipid monoglucosyldiacylglycerol (mglcdag) in the membrane of acholeplasma laidlawii, which is important for the spontaneous curvature, and is a regulatory site for the lipid surface charge density. a potential connection between activity and a conformational change of this enzyme, governed by essential lipid activators, was studied with purified mglcdag synthase in different lipid aggregates. critical fractions of a ...19979368025
effects on mollicutes (wall-less bacteria) of synthetic peptides comprising a signal peptide or a membrane fusion peptide, and a nuclear localization sequence (nls) -- a comparison with melittin.in order to investigate the effect of primary amphipathic peptides on mollicutes (wall-less bacteria), we have synthesised five molecules (p1, p2, p3, jm123, and jm133) comprising a 16 to 18-residue hydrophobic sequence and the nuclear localization sequence (nls) pkkkrkv of simian virus 40 large-t antigen, c-terminated by a cysteamide group. the hydrophobic cluster was in p1 the signal sequence of the heavy chain of caiman crocodilus immunoglobulin g and in jm123 the fusion peptide of human immu ...19979371427
purification of a phosphatase which hydrolyzes phosphatidic acid, a key intermediate in glucolipid synthesis in acholeplasma laidlawii a membranes.a phosphatidic acid phosphatase (pap; ec 3.1.3.4.), dephosphorylating phosphatidic acid (pa) to diacylglycerol (dag), was identified and purified from the plasma membrane of acholeplasma laidlawii a. after four purification steps, including membrane preparation, tween 20 solubilization, preparative gel electrophoresis and electro-elution, pap was purified about 400 times to near homogeneity. the molecular weight of pap was according to sds-polyacrylamide gel electrophoresis approximately 25 kda ...19979408176
cryo-tem and nmr studies of a micelle-forming phosphoglucolipid from membranes of acholeplasma laidlawii a and b.the chemical structure of a phosphoglucolipid from the membrane of the bacterium acholeplasma laidlawii strain b-pg9 has been determined by high resolution nmr to be 1,2-diacyl-3-o-[glycerophosphoryl-6-o-(alpha-d-glucopyranosyl-(1 -->2)-o-alpha-d-glucopyranosyl)]-sn-glycerol (gpdglcdag). it was concluded that this lipid has exactly the same structure as one of the phosphoglucolipids from a. laidlawii strain a-ef22. by cryo transmission electron microscopy (cryo-tem) and nmr diffusion techniques ...19979032946
lipid dependence and basic kinetics of the purified 1,2-diacylglycerol 3-glucosyltransferase from membranes of acholeplasma laidlawii.udp-glucose: 1,2-diacylglycerol 3-glucosyltransferase (ec 2.4.1.157), catalyzes the transfer of glucose from udp-glucose to diacylglycerol (dag) to yield monoglucosyldiacylglycerol (mglcdag) and udp. mglcdag is the first glucolipid along the glucolipid pathway, and a major (nonbilayer-prone) lipid in the single membrane of acholeplasma laidlawii. mglcdag is further glucosylated to give the major diglucosyldiacylglycerol (dglc-dag). the bilayer fractions of these lipids are crucial for the metabo ...19978995384
pathologic responses of lambs to experimental inoculation with acholeplasma laidlawii. 19969026067
nisin resistance distinguishes mycoplasma spp. from acholeplasma spp. and provides a basis for selective growth media.the sensitivity of 11 mycoplasma and 5 acholeplasma species to the bacteriocin nisin was determined. when applied on filter paper discs to lawns of acholeplasma cells, nisin (20 nmol per disc) gave 3.5- to 7.0-mm zones of growth inhibition. the inclusion of 0.2 mm nisin in agar medium reduced the number of acholeplasma laidlawii colonies by a factor of more than 10(6), and in a salts solution, 75 microm nisin killed more than 99.9% of cells within 1 min. under similar conditions, nisin had no si ...199611783455
[the sorption of antisense oligodeoxyribonucleotides by mycoplasma cells].the paper deals with kinetics of binding of antisense oligodesoxyribonucleotides, complementary to certain sequences 16 s rna of mollicutes, by the cells of three representatives of class mollicutes: acholeplasma laidlawii pg-8. mycoplasma pneumoniae fh and m. fermentans pg-18. it is shown that binding of antisense oligonucleotides by the mollicute cells depends on temperature and age of cultures. the highest level of sorption of labelled antisense oligodesoxyribonucleotides by the cells of myco ...19969044700
[the validation of the possible use of monosugars and 6-azacytidine for the elimination of mollicutes associated with hiv/aids from the human urogenital tract].a search for the methods new in principle which should block and eliminate aids-associated mycoplasmas was carried out. this work was conducted in two ways: 1) inhibition of vital activity of mycoplasma fermentans pg-18 and acholeplasma laidlawii pg-8 by 6-azacytidine; 2) establishment of carbohydrate composition of receptors for these mycoplasmas aimed at the competitive elimination of these microorganisms from urogenital tract of a man using carbohydrates. it is established that a 50%-inhibiti ...19969044715
[the binding and absorption by mollicute cells of antisignature analogs of oligodeoxyribonucleotides].processes of absorption and uptake of phosphorothioate, phosphorodithioate and methylphosphonate analogs of oligodeoxynucleotides which are complementary to "signature" 16s rrna sequences by cells of acholeplasma laidlawii pg-8. mycoplasma fermentans pg-18 and mycoplasma pneumoniae fh have been investigated. distinctions in efficiency of absorption by given cells of phosphorothioate and methylphosphonate analogs of oligonucleotides are found out. so, the level of thioates sorption by the cells o ...19969064069
fluctuations in ir spectral parameters detected in mixed acyl chain membranes of acholeplasma laidlawii b.acholeplasma laidlawii b cells were grown at 37 degrees c on three binary c16:0-d(31)/c18:1 fatty acid mixtures at initial mol ratios of 3:2, 1:1, and 2:3. these mol ratios produced final c16:0-d(31)/c18:1 lipid acyl chain mol ratios of 1.66 +/- 0.23 (n=6), 1.3 +/- 0.20 (n=6) and 0.58 +/- 0.09 (n=10), respectively, in the membrane of the microorganism. membrane conformational order for the deuterated and proteated acyl chains in intact cells was monitored by ft-ir spectroscopy through the thermo ...19968624360
characterization of the ftsz gene from mycoplasma pulmonis, an organism lacking a cell wall.the ftsz gene is required for cell division in escherichia coli and bacillus subtilis. in these organisms, ftsz is located in a ring at the leading edge of the septum. this ring is thought to be responsible for invagination of the septum, either causing invagination of the cytoplasmic membrane or activating septum-specific peptidoglycan biosynthesis. in this paper, we report that the cell division gene ftsz is present in two mycoplasma species, mycoplasma pulmonis and acholeplasma laidlawii, whi ...19968636032
chromatographic resolution of partially perdeuterated diglucosyldiacylglycerols from acholeplasma laidlawii.diglucosyldiacylglycerol from acholeplasma laidlawii was isolated by adsorption chromatography and subsequently subjected to molecular species analysis by reversed-phase high-performance liquid chromatography. twenty-three molecular species were resolved. the bacterium was grown in a medium supplemented with a mixture of oleic acid and perdeuterated palmitic acid, and incorporation of perdeuterated acyl moieties occurred in several molecular species. short and odd-numbered acyl chains were found ...19968673252
evaluation of current sterility tests for human live viral vaccines.current sterility tests for human viral vaccines were evaluated. a total of 43 lots of bulk suspension of live viral vaccines (measles, mumps, rubella and oral poliomyelitis) produced by six manufacturers in japan were evaluated for bacteriostatic and mycoplasmastatic activities. some of them showed fairly high bacteriostatic and mycoplasmastatic activities, due to antibiotics added during vaccine production. it was concluded that the current sterility test for mycoplasmas is not reliable to det ...19968733601
correlation between bilayer lipid dynamics and activity of the diglucosyldiacylglycerol synthase from acholeplasma laidlawii membranes.in the single membrane of acholeplasma laidlawii a specific glucosyltransferase synthesize the major, lamellar-forming lipid diglucosyldiacylglycerol (dglcdag) from the major, nonlamellar-prone monoglucosyldiacylglycerol (mglcdag). this is crucial for the maintenance of phase equilibria close to a bilayer-nonbilayer transition and a nearly constant spontaneous curvature in the membrane lipid bilayer. acyl chain order is also affected, but not kept constant. phosphatidylglycerol (pg) is an essent ...19968756472
[the effect of the mycoplasma contamination of 2 kidney cell sublines from the kangaroo rat on their karyotypic structure].the karyotypic variability has been investigated for two cell sublines of rat kangaroo kidney cultured for 40-160 days after contamination with acholeplasma laidlawii, strain pg-8. the contaminated cultures did not differ from non-contaminated ones in cell distribution for chromosome number. the majority of cells of subline nbl-3-11 with modal number of chromosomes displayed the main structural variant of the karyotype (svk)--2+2+2+2+2+1; in subline nbl-3-17 the main svk being 3+3+3+3+3+2. a com ...19968768552
[the detection of proteolytic enzymes in the culture broth of mollicutes].four strains of mollicutes different in their role in pathology of people, animals and plants have been studied to detect general proteolytic (caseinolytic) activity with results presented. proteolytic activity was determined both in the deposited proteins and in supersediment liquids under suturation with ammonium sulphate of 55 and 80%, respectively. maximum proteolytic activity was observed in supersediment liquids. it was 137.2 e per 1 mg of protein in m. fermentans pg-18; 106.2 in a. laidla ...19968777466
new aspects on membrane lipid regulation in acholeplasma laidlawii a and phase equilibria of monoacyldiglucosyldiacylglycerol.a new membrane lipid, monoacyldiglucosyldiacylglycerol (madglcdag), was recently discovered in acholeplasma laidlawii strain a-ef22, demanding a new study of the biosynthetic regulation, and the phase behavior, of the glucolipids in this organism. the only liquid-crystalline phase formed by madglcdag is a reversed hexagonal phase. a. laidlawii a-ef22 synthesizes four lipids that have the ability to induce the formation of reversed nonlamellar phases: madglcdag, monoglucosyldiacylglycerol (mglcda ...19968780516
sequence and organization of genes encoding enzymes involved in pyruvate metabolism in mycoplasma capricolum.the region of the genome of mycoplasma capricolum upstream of the portion encompassing the genes for enzymes i and iiaglc of the phosphoenolpyruvate:sugar phosphotransferase system (pts) was cloned and sequenced. examination of the sequence revealed open reading frames corresponding to numerous genes involved with the oxidation of pyruvate. the deduced gene organization is naox (encoding nadh oxidase)-lpla (encoding lipoate-protein ligase)-odpa (encoding pyruvate dehydrogenase ei alpha)-odpb (en ...19968844861
reduction of benzyl viologen distinguishes genera of the class mollicutes.we tested the ability of 62 growing strains belonging to the class mollicutes to reduce the redox indicator and free-radical generator 1,1'-dibenzyl-4,4'-bipyridinium dichloride (benzyl viologen [bv]) to a blue-violet-purple color. bv was reduced by 12 acholeplasma species but not by acholeplasma multiforme pn525t (t = type strain). bv was also reduced by five of nine mesoplasma species and by four of six entomoplasma species. bv was not reduced by 19 mycoplasma species, six spiroplasma species, ...19968863413
differential and strain-specific triggering of bovine alveolar macrophage effector functions by mycoplasmas.mycoplasma strains being considered as pathogenic or non-pathogenic for cattle were tested on their capacity to activate bovine alveolar macrophages in vitro. of particular interest was the behaviour of mycoplasma mycoides ssp. mycoides small colony type (m.m.m. sc), the causative agent of contagious bovine pleuropneumonia (cbpp). increases in procoagulant activity (pca), tumor necrosis factor-alpha- (tnf-alpha) and nitrogen monoxide (no) generation were tested. to minimize an influence of macro ...19968971688
differential scanning calorimetric study of the interaction of cholesterol with the major lipids of the acholeplasma laidlawii b membrane.it has been proposed that the lower levels of exogenous cholesterol incorporation into the membranes of the sterol-non-requiring as compared to the sterol-requiring mycoplasmas may be due to the much higher glycolipid content of the former and to the reduced ability of glycolipids, as opposed to phospholipids, to incorporate sterols [efrati et al. (1986) arch. biochem. biophys. 248, 282-288]. in order to test this hypothesis, we have investigated the interaction of cholesterol with the major mem ...19968988017
[the inhibition of translation in vivo in mollicutes by thiophosphate analogs of oligodeoxyribonucleotides].it is shown that the concentration of "antisignature" phosphorothioate analogs of oligodeoxynucleotides, complementary to the region of 165 rrna acholeplasma laidlawii pg-8 and mycoplasma fermentans pg-18 responsible tor binding with ribosomal protein s4 being 0.5--1 microm synthesis of proteins in vivo decreases to 70%. a model of mechanisms is suggested to block oligonucleotides of the process of in vivo translation in mollicutes by "antisignature" phosphorothioate analogs. the advantages of t ...19968991592
[clastogenic effect of mycoplasma on human chromosomes]. 19958535262
[a factor to enhance hiv replication in serum bearing a resemblance to membranes of acholeplasma laidlawii].we found a substance a in human serum by elisa method, using anti-a antibody. the substance a was obtained from the membranes of a. laidlawii and this enhanced hiv replication. this substance in human serum was detected in the chloroform phase of the bligh-dyer method. rf value in thin layer chromatography was 0.28. this substance clearly showed enhancement of hiv replication as well as the activity of the membranes of a. laidlawii, but did not induce tnf production. furthermore, the activity wh ...19958586892
influence of monoglucosyldiacylglycerol and monoacylmonoglucosyldiacylglycerol on the lipid bilayer of the membrane from acholeplasma laidlawii strain a-ef22.the ability for 1,2-diacyl-3-o-(alpha-d-glucopyranosyl)-sn-glycerol (mglcdag) and 1,2-diacyl-3-o-(6-o-acyl-(alpha-d-glucopyranosyl))-sn-glycerol (mamglcdag) to induce non-lamellar phases in a lipid mixture with an in vivo composition, prepared from acholeplasma laidlawii membranes, has been investigated. the phase transition temperatures from lamellar to non-lamellar structures were studied with varying fractions of mglcdag and mamglcdag. the transition temperature decreased from 73 +/- 2 degree ...19957488623
expression of foreign genes and selection of promoter sequences in acholeplasma laidlawii.the stable maintenance and expression of foreign genes in mollicutes (mycoplasmas) have been difficult to achieve due to the lack of suitable vectors. in this paper we show for the first time that a replicating vector can been used to express foreign genes other than antibiotic resistance genes in acholeplasma laidlawii. plasmids derived from the lactococcal vector pnz18 could introduce and maintain four different genes for many generations in a. laidlawii. one of these, encoding the dominant me ...19957496518
effects of pentachlorophenol and biotic interactions on soil fauna and decomposition in humus soil.in a laboratory experiment, effects of chemical stress (pentachlorophenol, pcp, at concentrations of 0, 50, and 500 mg/kg) and biotic interactions (nematodes in the presence or absence of collembolas and enchytraeids) on the community structure of soil animals and decomposition processes were studied. pcp was strongly adsorbed to humus that contained 65% organic matter. numbers of fungal-feeding nematodes decreased significantly at the highest pcp concentration, while no effects were found in ba ...19957498064
taxonomic analysis of the tortoise mycoplasmas mycoplasma agassizii and mycoplasma testudinis by 16s rrna gene sequence comparison.the nucleotide sequences of the 16s rrna genes of two mycoplasmas, mycoplasma agassizii (proposed sp. nov.) and mycoplasma testudinis, isolated from tortoises were determined and used for taxonomic comparisons. signature nucleotide sequence motifs and overall sequence similarities to other mollicutes positioned these mycoplasmas in the m. hyorhinis and m. pneumoniae phylogenetic groups, respectively. a third, previously unrecognized tortoise mycoplasma was detected by 16s rrna gene amplification ...19957537069
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