Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| the effect of cholesterol on the phase structure of glucolipids from acholeplasma laidlawii membranes. | 1. the packing properties in lipid mixtures containing cholesterol and membrane glucolipids from acholeplasma laidlawii are modified by varying the amounts of cholesterol, diacylmonoglucosylglycerol and diacyldiglucosylglycerol in the mixtures as well as the temperature and the degree of acyl chain unsaturation. these changes affect both the proportions of different lipids having dissimilar molecular geometries and the geometry of the lipid molecules themselves. 2. all mixtures containing glucol ... | 1981 | 7250125 |
| respiration-associated components of mollicutes. | no cytochrome pigments were detected by difference (reduced minus oxidized) spectroscopy at liquid nitrogen temperature in whole-cell preparations or membrane fractions of acholeplasma axanthum s273, acholeplasma equifetale n93, acholeplasma granularum bts39, acholeplasma laidlawii b-pg9, acholeplasma modicum pg-49, acholeplasma oculi 19l, mycoplasma arginini g230, mycoplasma arthritidis 07, mycoplasma pneumoniae fh, and mycoplasma pulmonis jb. all ten mollicutes species examined contained iron ... | 1981 | 7240087 |
| adenylate energy charge in acholeplasma laidlawii. | adenosine 5'-triphosphate, adenosine 5'-diphosphate, and adenosine 5'-monophosphate were produced by acholeplasma laidlawii b-pg9 growing in modified edward medium. the adenylate energy charge was calculated to be 0.84 +/- 0.07 and ranged from 0.91 to 0.78 during exponential growth (12 to 24 h). during exponential growth, a. laidlawii contained, at 17.5 h, 2.3 x 10(-17) mol of adenosine 5'-triphosphate per colony-forming unit and, at 16 h, 27.3 nmol of adenosine 5'-triphosphate per mg (dry weigh ... | 1981 | 7240083 |
| first observation of amino acid side chain dynamics in membrane proteins using high field deuterium nuclear magnetic resonance spectroscopy. | we have obtained the first deuterium nmr spectra of an individual membrane protein, bacteriorhodopsin in the purple membrane of halobacterium halobium r1. biosynthetic isotopic enrichment with [gamma-2h6]valine and high field fourier transform operation permitted rapid data acquisition on intact membranes, including measurement of relaxation times. at some temperatures high quality spectra could be obtained in less than 1 s. [u-14c]valine tracer studies indicate that less than or equal to 2% of ... | 1981 | 7217074 |
| effects of charged cholesteryl esters on mycoplasma growth. | 1980 | 7215545 | |
| lipid and protein membrane components associated with cholesterol uptake by mycoplasmas. | membranes of mycoplasma species take up 2--4 times more exogenous cholesterol than membranes of acholeplasma species. to test whether the lower cholesterol uptake capacity of acholeplasma is due to the high glycolipid content of their membranes, the phospholipids of acholeplasma laidlawii and mycoplasma capricolum membranes were hydrolyzed by phospholipase a2. digestion removed about 30% of the polar lipids of a. laidlawii, leaving the glycolipids and phospholglycolipids intact, and about 70% of ... | 1981 | 7213725 |
| reversed cubic phase with membrane glucolipids from acholeplasma laidlawii. 1h, 2h, and diffusion nuclear magnetic resonance measurements. | monoglucosyl diglyceride and diglucosyl diglyceride are the dominant lipids of the acholeplasma laidlawii membrane. diglucosyl diglyceride forms a lamellar liquid crystalline phase with water while monoglucosyl diglyceride forms a reversed hexagonal phase. depending on the amounts of unsaturated acyl chains of the lipids, a mixture of monoglucosyl diglyceride and diglucosyl diglyceride forms lamellar or reversed cubic phases at physiological temperatures. a high degree of cis unsaturation favors ... | 1981 | 7213607 |
| isolation of mycoplasma from a buffalo (bubalus bubalis) with mastitis. | 1981 | 7199239 | |
| effect of molecular weight of polyethylene glycols on inactivation of mycoplasma pulmonis and acholeplasma laidlawii a. | 1982 | 7186082 | |
| prevalence of mycoplasma and chlamydia in the nasal flora of dairy calves. | nasal swabs from dairy calves in 20 selected herds were collected once in each of three sampling periods in one year and cultured for mycoplasmas and chlamydiae. seventy-seven of 411 calves (19%) and 16 of 20 herds (80%) were positive for mycoplasmas at least once throughout the year, and all of 378 calves sampled from the 20 herds were negative for chlamydiae. thirty-one percent of the isolates were mycoplasma bovirhinis; other species isolated less frequently were mycoplasma bovis, mycoplasma ... | 1982 | 7179720 |
| replication of mycoplasma virus l51. vii. effect of chloramphenicol on the synthesis of dna replicative intermediates. | chloramphenicol affects several steps in the dna replication of mycoplasma virus l51, a noncytocidal, naked, bullet-shaped virion containing circular single-stranded (ss) dna of 1.5 x 10(6) daltons (4.5 kilobases). in the presence of chloramphenicol, adsorption was normal and parental ss dna was converted to double-stranded replicative forms (rf), but subsequent rf leads to rf replication was inhibited. chloramphenicol added late in infection, when most viral nascent dna is in progeny ss molecul ... | 1982 | 7176020 |
| comparison of the ultrastructural aspects of acholeplasma laidlawii grown in liquid and solid media. | 1982 | 7159213 | |
| [proteins of bacterial membranes. nadh-dehydrogenase from the cells of acholeplasma laidlawii]. | using ion-exchange chromatography on deae-cellulose and gel filtration, a purified nadh-dehydrogenase was prepared from cell membranes of a. laidlawii. the enzyme specific activity exceeds the activity of the membrane preparation 45-fold. the enzyme is thermolabile and sensitive to lecithine. electrophoresis of the enzyme preparation in the presence of na-ds resulted in two proteins with mr of 65 000 and 72 000. specific staining of the gels with triphenyltetrasolium chloride in the presence of ... | 1982 | 7150675 |
| preferential uptake of lipids by mycoplasma membranes from human plasma low-density lipoproteins. | the binding and transfer of low-density lipoprotein (ldl) constituents to mycoplasma membranes were examined. mycoplasma capricolum was found to bind more 125i-labeled ldl than acholeplasma laidlawii. free and esterified cholesterol uptake was 3-4 times higher in m. capricolum than in a. laidlawii. cholesterol transfer to the membranes of both organisms far exceeded the amounts of cholesterol expected according to ldl protein found associated with the membranes. trypsin digestion of the membrane ... | 1982 | 7150569 |
| [simultaneous isolation of infected and non-infected clones of mycoplasmas from plaques obtained on acholeplasma laidlawii lawns with a virus of group l1 of gourlay]. | 1982 | 7124157 | |
| the electrochemical potential across mycoplasmal membranes. | the electrochemical proton gradient across mycoplasmal membranes was studied. the transmembrane proton-motive potential, delta p, is composed of two parameters, a transmembrane electric potential difference, delta psi, and a transmembrane proton gradient, delta ph, according to the formula delta p = delta psi -(a x delta ph). membrane potentials were determined with use of potential-sensitive cyanine dyes. the delta psi for both mycoplasma mycoides subspecies capri and mycoplasma gallisepticum w ... | 1982 | 7123058 |
| lipid phase structure in the regulation of lipid composition in acholeplasma laidlawii membranes. | in acholeplasma laidlawii membranes the ratio between the dominating lipids, monoglucosyldiglyceride (mgdg) and diglucosyldiglyceride (dgdg), depends on temperature, configuration of incorporated fatty acids, and membrane cholesterol content, which affect the molecular geometry of the lipids. mgdg and dgdg have wedge- and rod-like molecular shapes, respectively, that are modifiable. the packing constraints of lipids in amphiphilic aggregates, i.e., the area of the hydrocarbon-water interface and ... | 1982 | 7123057 |
| active diffusion of adsorbed mycoplasmal virus l3 on acholeplasma laidlawii cell membranes. | 1982 | 7123047 | |
| lateral mobility of membrane-bound antibodies on the surface of acholeplasma laidlawii: evidence for virus-induced cell fusion in a procaryote. | dynamic processes on the membrane of the procaryotic cell acholeplasma laidlawii have been studied by means of immunoelectron microscopy. colloidal gold-labeled anti-a. laidlawii antibodies were used as electron-dense markers. this method allowed the demonstration of temperature-dependent lateral mobility of membrane-bound immunoglobulins. by using two different sizes of gold grains to differentiate cells from two different cell populations, virus-induced fusion of procaryotic cells could be sho ... | 1982 | 7118831 |
| virus capping on mycoplasma cells and its effect on membrane structure. | the capping of mycoplasmavirus l3 on the surface of acholeplasma laidlawii was investigated. in electron microscope studies we observed a reduced capping after treatment of the host cell with energy-blocking agents. other drugs inhibiting ligand capping on eucariotic cells had no effect. changes in membrane structure after virus adsorption were observed spectroscopically using the excimer fluorescence technique. the results are interpreted in terms of a lipid-protein phase separation in connecti ... | 1982 | 7115700 |
| serological investigation of horse sera for antibodies against mycoplasmas and acholeplasmas. | sera from horses with respiratory disease (rd) have been investigated using the complement fixation test, indirect hemagglutination test, enzyme immune assay, and the metabolic inhibition test, and sera from mares after abortion, using the complement fixation test, indirect hemagglutination test and enzyme immune assay, for antibodies against mycoplasma equirhinis, m subdolum, m. equigenitalium, m. pulmonis, m. felis, acholeplasma laidlawii, a. hippikon and a. equifetale. antibodies were found a ... | 1982 | 7112894 |
| identification of iron- and phosphorus-containing antigens of the acholeplasma laidlawii cell membrane. | 1982 | 7106296 | |
| a 2h-nmr study of acholeplasma laidlawii membranes highly enriched in myristic acid. | myristic acid specifically deuterated at several positions along the acyl chain was biosynthetically incorporated into the membrane lipids of acholeplasma laidlawii b to the level of greater than or equal to 90%. 2h-nmr was used to study the molecular order and lipid phase composition of the membranes as a function of temperature. isolated membranes and intact cells give rise to similar 2h spectra. below 25 degrees c the spectra exhibit a broad gel phase component which at 0 degrees c reaches th ... | 1982 | 7104342 |
| isolation and preliminary characterisation of mycoplasmavirus 20-p. | a mycoplasmavirus, mv 20-p, was isolated from the fastidious, slow-growing human mycoplasma 20-p, previously identified by the growth inhibition test as mycoplasma hominis type 2. its broth culture was ultracentrifuged into 35% saccharose, the pellet was resuspensed in buffer, and the suspension was dropped onto laws of the virus indicator acholeplasma laidlawii bcl-13. the virus was washed off the plaque areas by buffer. mv 20-p appeared in electron microscopy as spherical, enveloped particles ... | 1982 | 7098542 |
| isolation and identification of mycoplasmas from the respiratory tract of the white leghorn chicken in the sudan. | 1982 | 7093655 | |
| effects of cholesterol on the orientational order of unsaturated lipids in the membranes of acholeplasma laidlawii. a 2h-nmr study. | we have investigated by 2h-nmr the effects of the incorporation of cholesterol on the orientational order of unsaturated lipid acyl chains in the membranes of acholeplasma laidlawii b. this is the only 2h-nmr study to date of the influence of cholesterol in a biological membrane using specifically labelled fatty acids. we observed the characteristic condensing effect of cholesterol on the lipid acyl chain order in the liquid crystalline phase. in terms of the percentage increase in the quadrupol ... | 1982 | 7093275 |
| comparison of ciliostasis by mycoplasmas in mouse and chicken tracheal organ cultures. | the cilia-stopping effect of mycoplasmas of human and various animal origin in mouse and chicken tracheal organ cultures was studied. from the results in mouse tracheal organ cultures, the mycoplasma strains tested were divided into three groups: mycoplasma pulmonis m53, m pulmonis jb, m. pulmonis ok, m. mycoides subsp. mycoides pgl and m. gallisepticum s6 showed a strong cilia-stopping effect; m. pulmonis pg22, m. mycoides subsp. capri pg3, m. meleagridis 19729, m. neurolyticum type a and m. ar ... | 1982 | 7087799 |
| isolation of acholeplasma laidlawii from a giraffe (giraffa camelopardalis rothschildi) and a mouflon (ovis musimon). | 1982 | 7064318 | |
| immunological and functional activity of spleen lymphocytes from mice infected by acholeplasma laidlawii cells and rauscher virus. | the duration of acholeplasma laidlawii antigen persistence in mice, resistant to rausher leukemia virus, after infection with both a. laidlawii cells and rausher virus has been studied. the antigen persistence was accompanied by marked depression of immune response which was especially severe in case of mixed acholeplasmavirus infection. such immunosuppression and observed infiltration of the spleen with immature leukemic cells can be regarded as a preleukosis. immunosuppression was accompanied ... | 1982 | 7048811 |
| the use of differential scanning calorimetry and differential thermal analysis in studies of model and biological membranes. | differential scanning calorimetry (dsc), and to a lesser extent differential thermal analysis (dta), are powerful yet relatively rapid and inexpensive thermodynamic techniques for studying the thermotropic phase behavior of lipids in model and biological membranes, without the introduction of exogenous probe molecules. in this review the principles as well as the scope and limitations of dsc and dta are discussed first. the application of these techniques to the study of the thermotropic phase b ... | 1982 | 7046969 |
| adsorption of the tailed mycoplasma virus l3 to cell membranes. | the adsorption properties of the tailed bacteriophage l3 to acholeplasma laidlawii cells were studied. adsorption followed a biphasic curve. reversibility and virus heterogeneity were not sufficient to explain the break in the adsorption curve. binding studies showed that each colony-forming unit could bind about 350 virions. the electrostatic nature of l3 adsorption was indicated by the effect of cations, ph, and temperature on the adsorption rate constant. l3 adsorption appeared to have a requ ... | 1982 | 7042999 |
| isolation of acholeplasmas and a mycoplasma from vegetables. | the isolation of mollicutes from food has not been reported. to isolate mollicutes in the presence of high levels of unwanted bacteria, we first incubated fresh vegetables in liquid culture media containing lysozyme, ampicillin, and thallous acetate. culture fluids were than separated from the vegetable samples, subjected to one freeze-thaw cycle, and passed through a filter of 0.4-micron porosity. filtered samples were cultured in sp4 medium and in a conventional medium containing horse serum. ... | 1982 | 7036899 |
| a note on positive bactec readings produced by mycoplasma. | 1981 | 7024236 | |
| [investigation of mare sera for antibodies against acholeplasmas and mycoplasmas with ther enzyme linked immunosorbent assay (elisa) (author's transl)]. | after abortion sera were taken from 58 thoroughbred and other mares of the northwestern part of germany and investigated by elisa (enzyme linked immuno-sorbent assay) for antibodies against mycoplasma equirhinis, m. subdolum, m. equigenitalium, m. pulmonis, m. felis, acholeplasma laidlawii, a. hippikon, and a. equifetale. reactions at serum dilutions of 1:32 and higher were considered as positive. at serum dilution 1:32 no antibodies were found in 11 sera. the remaining sera showed antibodies ag ... | 1980 | 7006267 |
| differentiation of mycoplasmatales from bacterial protoplast l-forms by assay for penicillin binding proteins. | membrane proteins with the specific ability for binding penicillin with high affinity (penicillin binding proteins) were found to be present in two strains of the cell wall-less protoplast l-form of p. mirabilis and were absent from different species of mycoplasma and from acholeplasma laidlawii. thus, the assay for penicillin binding proteins appeared to be suitable for the differentiation of the cell wall-less procaryotes. the absence of penicillin binding proteins from the mycoplasmatales fur ... | 1980 | 7004379 |
| [mycoplasmas isolated from the genital tract of mares (author's transl)]. | mycoplasmas were isolated from 11 (=#6,8%) of 161 cervix swabs from infertile mares. a total of 17 strains was isolated and characterized by indirect immunofluorescent test and metabolic inhibition test as mycoplasma equigenitalium (11 strains), mycoplasma subdolum (2 strains), acholeplasma laidlawii (3 strains) and acholeplasma equifetale (1 strain). in addition cervix swabs of the mares were investigated for bacteria. there was no specific correlation between presence of mycoplasmas and bacter ... | 1980 | 6999784 |
| [submicroscopic organization of certain mycoplasma species]. | the following mycoplasma species have been studied by the method of ultrathin sections: a. laidlawii, m. hominis, m. arthritidis, m. gallesepticum. after fixation both in the presence and in the absence of sucrose and magnesium material of medium electron density, resembling a microcapsule, could be detected on the surface of all mycoplasmas under study. the cytoplasmic membranes of a. laidlawii, m. hominis and m. arthritidis had a symmetric or asymmetric profile, depending on the method of fixa ... | 1980 | 6996392 |
| distinguishing between mn-containing and fe-containing superoxide dismutases in crude extracts of cells. | 1980 | 6994652 | |
| disposition of exposed antigens on the faces of isolated mycoplasma gallisepticum membranes. | the transverse disposition of exposed protein antigens on the two faces of isolated mycoplasma gallisepticum membranes have been investigated by using indirect immunoferritin labeling to accomplish visualization of the antigens at the ultrastructural level. comparison between the labeling patterns obtained with unabsorbed specific mycoplasma antiserum and antiserum from which antibodies directed against outer side determinants had been removed revealed that the majority of protein antigens were ... | 1980 | 6991483 |
| [immunologic and functional activity of the lymphocytes of mice infected with acholeplasma laidlawii and rauscher virus]. | 1980 | 6988017 | |
| phospholipid polymers--synthesis and spectral characteristics. | a new approach has been developed for the study of model and natural biomembranes. this involves the cross-linking of diacetylene groups after ultraviolet irradiation. for the study of model biomembranes, pure phospholipids (phosphatidylcholines) have been synthesized containing diacetylene groups in each acyl chain. the physical properties of these lipids have been examined and the conditions under which they polymerise have been determined. polymerisation occurs when the lipid is in a crystall ... | 1980 | 6893417 |
| the temperature dependence of molecular order and the influence of cholesterol in acholeplasma laidlawii membranes. | 2h nuclear magnetic resonance (nmr) of acholesplasma laidlawii membranes grown on a medium supplemented with perdeuterated palmitic acid shows that at 42 degrees c or above, the membrane lipids are entirely in a fluid state, exhibiting the characteristic 'plateau' in the variation of deuterium quadrupolar splitting with chain position. between 42 and 34 degrees c there is a well-defined gel-to-fluid phase transition encompassing the growth temperature of 37 degrees c, and at lower temperatures t ... | 1980 | 6892886 |
| acholeplasma laidlawii membranes: a fourier transform infrared study of the influence of protein on lipid organization and dynamics. | fourier transform infrared spectroscopy is applied to the study of intact and deproteinated plasma membranes of acholeplasma laidlawii, enriched biosynthetically with perdeuteriopalmitoyl chains. the temperature-dependent behavior is monitored via the cd stretching modes and compared with that observed in the model membrane 1,2-diperdeuteriopalmitoyl-sn-glycero-3-phosphocholine. the broad ramplike transition observed in the natural membranes is shown to consist of two overlapping stages. in the ... | 1980 | 6892608 |
| lipid-phase transition of phosphatidylglycerol in acholeplasma laidlawii membranes studied with phospholipase a2. | phospholipase a2 was applied to follow the lipid phase transition of phosphatidylglycerol in the membrane of acholeplasma laidlawii. the conclusions were identical with those obtained with physicochemical techniques. in addition, it was shown that phosphatidylglycerol undergoes the lipid phase transition in the same temperature range as the bulk of the membrane lipid; phase segregation between various molecular species of phosphatidylglycerol occurs; exchange of this phospholipid between rigid a ... | 1982 | 6889758 |
| cell culture media: contamination at flow labs. | 1983 | 6888532 | |
| polyethylene glycol-dependent transfection of acholeplasma laidlawii with mycoplasma virus l2 dna. | phenol-extracted dna from mycoplasma virus l2 was able to transfect acholeplasma laidlawii in the presence of polyethylene glycol. transfection was sensitive to dnase and was most efficient with 36% (wt/vol) polyethylene glycol 8000 and cells in logarithmic growth. virus production by the transfected cells was similar to that of the cells infected by intact virus. l2 dna transfected a. laidlawii with a single-hit dose-response curve, reaching saturation at high dna concentrations. optimum transf ... | 1983 | 6874642 |
| membrane isolation alters the gel to liquid crystal transition of acholeplasma laidlawii b. | the gel to liquid crystal phase transition of membrane lipids of live acholeplasma laidlawii b was monitored by infrared spectroscopy. it was found that, while isolated membranes are predominantly in the gel phase at the growth temperature, the live cell membranes contain a large liquid crystal phase component. | 1983 | 6849129 |
| the biosynthetic incorporation of diacetylenic fatty acids into the biomembranes of acholeplasma laidlawii a cells and polymerisation of the biomembranes by irradiation with ultraviolet light. | acholeplasma laidlawii a has been grown in media containing synthetic, long chain c20- and c23-fatty acids possessing a diacetylene group in their acyl chains. growth on the c23 diacetylenic acid was poor but was good on the c20 acid. biosynthetic incorporation of the fatty acids occurs; as much as 90% of the membrane lipid fatty acyl chains consisting of the c20-diacetylenic fatty acid, the remainder being shorter chain, saturated fatty acids. the thermal phase transition of this biomembrane ha ... | 1983 | 6838876 |
| characterization of the enveloped plasmavirus mvl2 after propagation on three acholeplasma laidlawii hosts. | plasmavirus mvl2 was propagated on three acholeplasma laidlawii strains, ja1, s2, or bc1-13. previously reported host-controlled modification (hcm) of mvl2, as reflected by changes in plating efficiency, was observed. adsorption rates and one-step growth curves varied according to host used. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the three mvl2 populations revealed differences in polypeptide profiles. | 1983 | 6830442 |
| properties of the nucleases of mollicutes. | extracts of the mollicutes acholeplasma equifetale, acholeplasma laidlawii b, mycoplasma arthritidis. mycoplasma pulmonis, and mycoplasma pneumoniae had dnase and endonuclease activity. a. laidlawii b had at least two peaks of dnase activity in sucrose gradients with sedimentation coefficients of 3.1s and 4.3s. these fractions also had endonuclease activity with different substrate specificities. a. laidlawii b may have more than two peaks of endonuclease activity in sucrose gradients. | 1982 | 6811565 |
| monoclonal antibodies specific for cell culture mycoplasmas. | mycoplasma infection of cell cultures is still a major problem in some laboratories. although several methods can be used for their detection, identification is normally by serological procedures. as no commercial source for the necessary antibodies is available we have prepared monoclonal antibodies to the five mycoplasma species that account for the majority of cell culture infections. these antibodies have been characterized by the growth inhibition test (git), immunofluorescence, and enzyme ... | 1982 | 6811415 |
| interactions of acholeplasma laidlawii cells with mouse spleen lymphocytes. | interaction between acholeplasma laidlawii cells labelled with oleic acid and mouse spleen lymphocytes depended on the time of incubation, on the temperature and on the quantitative ratio between both cells. uncouplers and edta did not influence the intensity of attachment. the resistance of binding to cytochalasin b amd glutaraldehyde as well as localization of a. laidlawii antigens on the lymphocyte surface and experiments with [14c] uridine-labelled mycoplasmas are an evidence against the par ... | 1981 | 6797154 |
| release of a group 1 mycoplasma virus from acholeplasma laidlawii after treatment with mitomycin c. | a rod-shaped group 1 mycoplasma virus was released from acholeplasma laidlawii strain ja2 after treatment with 2.5 mug of mitomycin c per ml. similar treatment of a. laidlawii strain bju failed to stimulate release of any pfu. | 1981 | 6793734 |
| protective efficacy of mycoplasma pneumoniae polysaccharides. | mycoplasma pneumoniae accounts for up to 35% of all pneumonias at times when influenza epidemics are not prevalent. therefore, considerable efforts have been directed towards the developmemt of a vaccine against mycoplasmal respiratory tract disease. the protective efficacy of inactivated m. pneumoniae vaccine, prepared so far, did not exceed 67%. this incomplete protective effect may have been due to insufficient immunogenicity and/or to failure of vaccines administered by the parenteral route ... | 1981 | 6793538 |
| [biochemical and serologic study of acholeplasmae isolated from monkeys]. | biochemical and serological properties of mycoplasmas isolated from the blood, feces and parenchymatous organs of monkeys have been studied to determine their species. it was established that the isolated strains belong to the family acholeplasmatoceae. the study of their biochemical properties in different tests has revealed the presence of 5 biochemically heterogeneous groups. their serological properties suggest that 13 out of 45 strains are identical to the reference strain of a. laidlawii a ... | 1981 | 6787821 |
| [use of the growth inhibition test, the cft, and the agar gel diffusion precipitation test to identify mycoplasmae isolated from monkeys]. | the data are presented on comparative evaluation of the growth inhibition test (git), the diffuse precipitation test in agar gel (dptag) and the complement fixation test (cft) in the identification of mycoplasma isolated from monkeys. the results obtained in the study of 4 mycoplasma strains from the internal organs of monkeys in the cft and the dptag with hyperimmune rabbit sera provided by microbiological associates, bethesda, maryland, usa, allowed these mycoplasma to be identified as m. laid ... | 1980 | 6778034 |
| a novel method for the determination of electrical potentials across cellular membranes. ii. membrane potentials of acholeplasmas, mycoplasmas, streptococci and erythrocytes. | the membrane potentials of acholeplasma laidlawii, mycoplasma mycoides subsp. capri, mycoplasma gallisepticum, streptococcus faecalis and human erythrocytes have been determined by applying a novel technique. the membrane potentials were calculated simply from potassium concentrations determined by atomic absorption spectroscopy, and gravimetry. the versatility of the new technique is demonstrated by comparing our results with data obtained by different techniques. | 1980 | 6773575 |
| [polysaccharide participation in bacterial wall permeability]. | 1980 | 6773273 | |
| dialogue between membranes and their lipid-metabolizing enzymes. | 1980 | 6768613 | |
| [equine mycoplasma typing using the direct immunofluorescence technic]. | 1982 | 6764691 | |
| emmy klieneberger-nobel award lecture: the protein fingerprints of mycoplasmas. | the proteins of 91 strains of mycoplasma from 19 established species and three groups of uncertain taxonomic position were separated by two-dimensional polyacrylamide gel electrophoresis. considerable variations in protein patterns were found among strains from the same species or subspecies; the percentage of matching spots (% of congruence) ranged from 42%-100%, but many proteins were strongly conserved in all strains of a given species. maps of these conserved proteins could be used to identi ... | 1982 | 6750757 |
| [effect of the geroprotector 2-ethyl-6-methyl-3-hydroxypyridine chlorhydrate on the cell proliferation of acholeplasma laidlawii]. | 1984 | 6734406 | |
| detection of mycoplasmas infecting cell cultures by dna hybridization. | infection of cell cultures by mycoplasmas can be detected and the mycoplasma identified by southern blot hybridization of the eco ri-digested dna of the suspected cell cultures with a nick-translated probe consisting of cloned ribosomal rna genes of mycoplasma capricolum. the probe does not hybridize with eukaryotic dna. the hybridization pattern with mycoplasmal dna is species specific, enabling the identification of the four most prevalent mycoplasma contaminants, mycoplasma orale, mycoplasma ... | 1984 | 6724620 |
| elimination of mycoplasmas from cell cultures and establishment of mycoplasma-free cell lines. | several antibiotics were examined for their potential to eliminate mycoplasmas from contaminated cell cultures. acholeplasma laidlawii, mycoplasma arginini, mycoplasma hyorhinis and mycoplasma orale were effectively eliminated from experimentally contaminated mouse fibroblasts and mink epithelial cells by the use of the antibiotics minocycline and tiamutin . an elimination procedure was established, which involved the consecutive treatment of the cultures over a period of 3 weeks, followed by ce ... | 1984 | 6723803 |
| [comparative study of transformation and fusion induced by polyethylene glycol in acholeplasma laidlawii b]. | this study showed in acholeplasma laidlawii the possibility of transformation and fusion of protoplasts after induction by polyethylene glycol. recombination in a genome of the resistance to chloramphenicol and neomycin has been obtained. minimal inhibitory concentration of these antibiotics towards the recombined strain are identical to those measured with the parental strains. the most suitable experimental conditions have been studied. it appeared that the fusion, which is cared out more easi ... | 1984 | 6713302 |
| isolation and pathogenicity of mycoplasmas from geese. | several mycoplasma isolation trials were performed on infertile goose eggs and goose embryos which died during incubation, as well as on geese of different ages. a total of 43 out of 110 goose eggs proved to be contaminated by mycoplasmas. upon autopsy of birds which laid positive eggs, lesions were observed in the airsacs. mycoplasmas could be isolated from their air sacs and oviduct. four out of 15 strains examined biochemically and serologically with antisera prepared against all known avian ... | 1984 | 6712063 |
| effect of novobiocin on mycoplasma virus l2 replication. | l2 is a temperate mycoplasma virus containing 11.8 kilobase pairs of negatively superhelical double-stranded dna. we observed l2 dna with less superhelicity in novobiocin-treated cells than that in untreated cells. however, although no change in viral dna superhelicity could be found in novobiocin-treated novobiocin-resistant cells, l2 production decreased in these novobiocin-treated cells. | 1984 | 6690717 |
| persistence of acholeplasma laidlawii in an established cell line rl 19. 1. host-parasite morphology. | the cell-parasite relationship of epitheloid cells from the established liver cell line rl 19 persistently infected with acholeplasma laidlawii was studied by transmission electron microscopy and scanning electron microscopy. the predominantly filamentous, branched a. laidlawii were arranged horizontally on the cell surface between microvilli at the cell margin. the cell adhesion, spreading, growth pattern and cell surface shape were not altered in relation to uninfected cultures of the same cel ... | 1983 | 6685661 |
| survey of plasmids in various mycoplasmas. | thirty-three strains representing 15 distinct mycoplasma, acholeplasma, and spiroplasma species were examined for the presence of plasmid dna by agarose gel electrophoresis. the electrophoretic patterns of the dnas of three strains, mycoplasma sp. strain 747, spiroplasma mirum strain smca, and m. hominis strain 1257, suggested the presence of a plasmid with molecular weights of approximately 70, 10, and 9 megadaltons, respectively. the functions of these plasmids are currently unknown. | 1983 | 6679154 |
| 19f-nuclear magnetic resonance study of glycerolipid fatty acyl chain order in acholeplasma laidlawii b membranes. | the technique of 19f-nuclear magnetic resonance (19f-nmr) spectroscopy offers a number of advantages for studies of lipid fatty acyl chain orientation and dynamics in biomembranes. however, the geminal difluoromethylene fatty acid probes usually employed in such studies appreciably perturb the organization of lipid bilayers. we have thus synthesized a series of specifically monofluorinated palmitic acids and carried out biophysical, biochemical, and physiological studies establishing their suita ... | 1983 | 6679141 |
| [instability of host-virus association in acholeplasma laidlawii infected by a mycoplasma virus of the gourlay group l1]. | since l 1 mycoplasmaviruses have been described by gourlay for acholeplasma laidlawii, two hypotheses tried to explain the relationships between virus and host, the first by a "gradual lysis", the second on the basis of a "reduced growth" of infected acholeplasmas. neither has implied that susceptible cells, free of virus, can be obtained from infected populations, the cells being supposed to die according to the first and to be all infected but still slowly dividing according to the second hypo ... | 1983 | 6675342 |
| [accumulation of cholesterol in acholeplasma laidlawii membranes in the steady-state phase of culture growth]. | in early logarithmic phase of growth of the a. laidlawii cells the lipid composition of plasma membrane is changed: the total lipid, glycolipid and phospholipid contents are decreased, while that of cholesterol changes only insignificantly. in late logarithmic and steady state phases the cholesterol level in the membrane is increased in parallel with the decrease of the phospholipid content. throughout the growth period a quantitative redistribution of membrane phospholipids in fatty acids and a ... | 1983 | 6661465 |
| [interaction of acholeplasma laidlawii and mycoplasma arthritidis with the lymphocytes of mice of different strains]. | the interaction of mycoplasmas and mouse lymphocytes has been studied by the microbiological and electron-microscopic methods. the experiments have shown that a. laidlawii and m. arthritidis are adsorbed on lymphocytes and thymocytes of (c57bl6 x a/he)f1, balb and c57bl mice after 15 minutes of their joint incubation at 37 degrees c, 1 hour later adsorption reaches its maximum intensity and after further prolongation of the time of incubation the number of adsorbed microbial cells remains unchan ... | 1983 | 6659765 |
| transport activity of mouse spleen lymphocytes after their interaction in vitro with acholeplasma laidlawii cells. | transport of two non-metabolized carbohydrates (3-o-methyl-d-glucose, 3-o-mg, and 2-deoxy-d-glucose, 2-dg) into mouse spleen lymphocytes after their interaction with acholeplasma laidlawii cells has been studied. incubation of a. laidlawii cells and particularly the liposomes prepared from a. laidlawii membrane lipids enhances the rates of the both carbohydrates transport. this treatment resulted in increasing of the vmax values of 3-o-mg and 2-dg without changing the km values. this stimulation ... | 1983 | 6659737 |
| synthesis of adenylate nucleotides by mollicutes (mycoplasmas). | cultures of the mollicutes (mycoplasma) acholeplasma laidlawii b, acholeplasma morum, mycoplasma bovis, mycoplasma arginini, mycoplasma fermentans and mycoplasma gallisepticum, representing four metabolic groups, were sampled at intervals over a 40 to 50 h period and assayed for the numbers of c.f.u., changes in ph and glucose concentration, and concentrations of atp, adp, amp, lactate and pyruvate. the adenylate energy charge (eca), the mean generation time, and the number of nmol of atp (mg dr ... | 1983 | 6655457 |
| fluorine-19 nuclear magnetic resonance studies of lipid fatty acyl chain order and dynamics in acholeplasma laidlawii b membranes. effects of methyl-branch substitution and of trans unsaturation upon membrane acyl-chain orientational order. | the hydrocarbon-chain orientational order parameters of membranes of acholeplasma laidlawii b enriched with straight-chain saturated, methyl iso-branched, methyl anteiso-branched, or trans-unsaturated fatty acids have been determined via fluorine-19 nuclear magnetic resonance spectroscopy (19f nmr). a theoretical description of the 19f nmr spectral line shape is presented that permits the determination of the orientational order parameters associated with specifically monofluorinated palmitic ac ... | 1983 | 6652059 |
| fluorine-19 nuclear magnetic resonance studies of lipid fatty acyl chain order and dynamics in acholeplasma laidlawii b membranes. a physical, biochemical, and biological evaluation of monofluoropalmitic acids as membrane probes. | fluorine-19 nuclear magnetic resonance spectroscopy offers a number of unique advantages for studies of lipid fatty acyl chain order and dynamics in model and biological membranes. however, the germinal difluoromethylene fatty acids commonly employed as 19f membrane probes appear to appreciably perturb the organization of model membranes and biomembranes. we have thus synthesized a series of specifically labeled monofluoropalmitic acids and evaluated these as suitable membrane probes. differenti ... | 1983 | 6652058 |
| intraspecies genetic relatedness among strains of acholeplasma laidlawii and of acholeplasma axanthum by nucleic acid hybridization. | this study compares the intraspecies genetic relatedness among strains of two established species of acholeplasma. radiolabelled dna probes were prepared from three strains of acholeplasma laidlawii and two strains of acholeplasma axanthum, by using the nick translation method. the labelled dna probes of these two strains were hybridized to an excess of unlabelled dna from 12 strains of acholeplasma laidlawii and from six strains of acholeplasma axanthum, respectively. nucleic acid hybridization ... | 1983 | 6631407 |
| uridine phosphorylase from acholeplasma laidlawii: purification and kinetic properties. | uridine phosphorylase was purified 1,370-fold from sonicated extracts of acholeplasma laidlawii by ammonium sulfate precipitation, deae-sephadex column chromatography, hydroxylapatite chromatography, and sephadex g-200 fractionation. the molecular weight of the enzyme as determined by gel filtration was approximately 65,000. [u-14c]ribose-1-phosphate (rib-1-p), prepared enzymatically from [u-14c]inosine, was utilized in initial velocity studies of uridine synthesis, which indicated a sequential ... | 1983 | 6619095 |
| uracil phosphoribosyltransferase from acholeplasma laidlawii: partial purification and kinetic properties. | uracil phosphoribosyltransferase was purified 34-fold from sonicated extracts of acholeplasma laidlawii by ammonium sulfate precipitation, binding to deae-sephadex, sephadex g-200 chromatography, and hydroxylapatite chromatography. the molecular weight of the enzyme by gel filtration was approximately 80,000. the ph optimum for phosphoribosylation was around 7.5, and the optimum mgcl2 concentration was 5 mm. initial velocity studies were conducted over a wide range of both uracil and 5-phosphori ... | 1983 | 6619094 |
| [mycoplasma mastitis of cattle. 11. histological udder findings after experimental infection with mycoplasma bovigenitalium and acholeplasma laidlawii]. | 1983 | 6615133 | |
| [mycoplasma mastitis of cattle. 10. test of mycoplasma bovis, mycoplasma bovigenitalium and acholeplasma laidlawii for udder pathogenicity]. | 1983 | 6615132 | |
| the effects of ionizing radiation on the peroxide content of a pure polyunsaturated lipid dispersion and of lipids and membranes derived from acholeplasma laidlawii. | dispersions of a pure unsaturated phospholipid, dilinoleoylphosphatidyl choline, formed conjugated diene hydroperoxides when irradiated in air with 7 mev electrons (150 gy and 300 gy). peroxide formation was optimized when the dispersions were irradiated in air at 37 degrees c at a dose rate of 5 gy/min. no significant loss of linoleic acid from the irradiated phospholipid dispersions was observed after doses of 150 or 300 gy. small amounts of thiobarbituric acid-reactive material were formed in ... | 1984 | 6607230 |
| radiation studies of acholeplasma laidlawii: the role of membrane composition. | acholeplasma laidlawii, a mycoplasma, is unable to synthesize unsaturated fatty acids but it will incorporate them into its plasma membrane if they are supplied exogeneously. thus the fatty acid composition of the cell membrane can be defined by growing the organism in media containing specific fatty acids. we obtained cells with predominantly one type of unsaturated fatty acid (either oleic, linoleic or linolenic acid) or cells with only saturated fatty acid in the cell membrane. the cells were ... | 1983 | 6605325 |
| bacterial membranes and lipid packing theory. | recent physical studies on the lipids of biological membranes have emphasized the potential instability of the lamellar phase of mixtures of lipids containing unsaturated species of phosphatidylethanolamine, plasmenylethanolamine, or monoglycosyldiacylglycerols, all of which are important constituents of the membranes of different groups of prokaryotes. the polar lipid compositions of bacteria are examined in terms of lipid packing theory. this survey reveals that gram-negative species with high ... | 1984 | 6530599 |
| fatty acyl chain structure, orientational order, and the lipid phase transition in acholeplasma laidlawii b membranes. a review of recent 19f nuclear magnetic resonance studies. | the orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of acholeplasma laidlawii b in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19f nuclear magnetic resonance (19f nmr) spectroscopy. it is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and b ... | 1984 | 6525566 |
| calorimetric and spectroscopic studies of lipid hydrocarbon chain order in the acholeplasma laidlawii membrane. | the thermotropic phase behavior of acholeplasma laidlawii b membranes, whose lipids were biosynthetically highly enriched with one of a wide variety of different types of fatty acyl groups, was studied by differential scanning calorimetry. the membrane-lipid-hydrocarbon chain orientational order of these membranes, in both the gel and liquid-crystalline states, was also investigated by 19f-nuclear magnetic resonance spectroscopy, using biosynthetically incorporated monofluoropalmitic acid probes ... | 1984 | 6511356 |
| effects of acyl chain composition on production of mycoplasmavirus mv-l2 by acholeplasma laidlawii. | membrane-enveloped viruses obtain their lipid envelopes from the host cells. studies with animal viruses and different cell lines have shown that the composition of the virus envelope affects infectivity. in this study, acholeplasma laidlawii strain ja1 and the membrane-enveloped virus mv-l2 were used. in this system, it is possible to vary the "stiffness" of the host cytoplasmic membrane within a very wide range by adding different fatty acids to the growth medium. viruses with different envelo ... | 1984 | 6511354 |
| autoxidation of acholeplasma laidlawii membranes. | autoxidation of acholeplasma laidlawii membranes (with equimolar ratio of palmitic and linoleic acid) lacks an obvious induction period, and the overall rate of disappearance of substrate does not follow closely that of typical autocatalytic kinetics. throughout the course of autoxidation, the major oxygenated products isolated were hydroperoxides (as hydroxy esters) and compounds that gave rise to trihydroxy esters. the yield of trihydroxy esters was appreciable even at the early stage of the o ... | 1984 | 6503621 |
| two cholesterol pools in acholeplasma laidlawii membranes. | cholesterol exchange kinetics between [14c]cholesterol-labeled acholeplasma laidlawii and mycoplasma gallisepticum cells and phosphatidylcholine-cholesterol vesicles followed a biphasic curve, with faster exchange rates for a. laidlawii. the same biphasic curve was obtained with isolated membranes. cholesterol exchange between lipid vesicles and a. laidlawii cells depleted of phospholipids by phospholipase a2, fitted a monophasic linear curve. the data support the hypothesis that the biphasic ch ... | 1984 | 6479337 |
| purification and properties of a manganese-containing superoxide dismutase from acholeplasma laidlawii. | from the prokaryotic microorganism acholeplasma laidlawii the major manganese-containing superoxide dismutase has been purified to homogeneity, as judged by polyacrylamide gel electrophoresis. the molecular mass of the enzyme was found to be 41 500 da. it consists of two subunits of identical size and has an isoelectric point of 6.4. the enzyme contains 0.51 +/- 0.05 atoms of manganese per subunit. its amino-acid composition and light absorption spectra are presented and compared with mn- and fe ... | 1984 | 6469219 |
| altered surface structure of acholeplasma laidlawii induced by mycoplasmavirus l3 infection. | 1981 | 6456906 | |
| [proteins of bacterial membranes. purification of soluble atpase from acholeplasma laidlawii]. | a purified preparation of atpase (factor f1) from the acholeplasma laidlawii was obtained. the purification procedure included extraction of the enzyme complex from the isolated membranes by ultrasonication, chromatography on deae-cellulose and gel filtration on sepharose 6b. the specific activity of the atpase was increased 30-fold as compared to the original activity. the km value for atp hydrolysis was 7,4 . 10(-4) m. adp competitively inhibited the enzyme (ki = 2,0 . 10(-4) m). ouabain (2,5 ... | 1980 | 6452174 |
| membrane lipid physical state and modulation of the na+,mg2+-atpase activity in acholeplasma laidlawii b. | careful analysis of the arrhenius plot of the na+,mg2+-atpase (atp pyrophosphohydrolase, ec 3.6.1.8) activity in acholeplasma laidlawii b membranes of varying fatty acid composition has been combined with differential thermal analysis of the membrane lipid phase transitions to evaluate the effects of membrane lipid properties on the enzyme activity. our results indicate that the enzyme is active only in association with liquid-crystalline lipids, exhibiting a significant heat capacity of activat ... | 1980 | 6445554 |
| binding of mvl-2 virus to a. laidlawii cells. | binding of mvl-2 virus, whose envelope lipids were radioactively labeled, to a. laidlawii ja1 cells was determined and characterized. the binding followed first-order kinetics and was temperature-dependent. all mvl-2 particles were capable of binding to a. laidlawii cells. at least 75 percent of radioactive mvl-2 bound represented specific binding which was markedly inhibited by edta. virus infectivity was not essential for binding as inactivation of the virus by ultraviolet irradiation did not ... | 1983 | 6433585 |
| interspecies and intraspecies dna homology among established species of acholeplasma: a review. | radiolabeled dna probes prepared in vitro by the nick translation method were used to determine the nucleotide sequence homology among the eight established and one unclassified species of acholeplasma. very little dna homology (2 to 21 percent) was found among these nine distinct species and the heteroduplexes showed at least 15 percent mismatching as determined by thermal elution endpoints. the data obtained by hybridization analyses paralleled the results obtained by the growth inhibition and ... | 1983 | 6433583 |
| effects of manganese on the growth and morphology of ureaplasma urealyticum. | all of the 14 serotype standard strains of ureaplasma urealyticum were inhibited to varying degrees by manganese. a 1 mm concentration of this cation either stopped growth or reduced the rate of growth in liquid medium. the presence of manganese also altered colonial morphology and cellular ultrastructure. inhibition was dose dependent and strain specific. this differential response allowed the serotype strains to be divided into two broad biotypes. for the first biotype (serotypes 1, 3, 6, and ... | 1984 | 6432835 |
| extraction of lipids during freeze-substitution of acholeplasma laidlawii-cells for electron microscopy. | cells of the bacterium acholeplasma laidlawii were rapidly frozen against a copper block cooled by liquid helium. the frozen cells were transferred to liquid nitrogen and subsequently to acetone or methanol at 183 k. after 24 h the cells were infiltrated at 203 k with a non-polar methacrylate resin of the same type as lowicryl hm20. the resin was cured at the same temperature. acetone extracted approximately 5% of the lipid content of the cells, methanol 15-45% and the resin only negligible amou ... | 1984 | 6429337 |
| insect cell cultures in the study of attachment and pathogenicity of spiroplasmas and mycoplasmas. | the insect cell lines dm-1 (drosophila melanogaster), as-2 (aceratagallia sanguinolenta) and ac-20 (agallia constricta) were infected with spiroplasmas, mycoplasmas and acholeplasma laidlawii. in dm-1 cultures maintained at 25 degrees c in m1a medium, all strains multiplied except m. hyorhinis and the uncultivable sex-ratio organism. spiroplasma citri r8a2, s. floricola bnr-1 and obmg, s. apis pps-1 and the strains bc-3, corn stunt spiroplasma (css) and 277f produced cytopathogenic effects (cpe) ... | 1984 | 6424527 |
| effect of mycoplasma infection on pyruvate dehydrogenase complex activity of normal and pyruvate dehydrogenase complex-deficient fibroblasts. | the fermentative mycoplasmas a. laidlawii js, m. hyorhinis dbs-50, m. hyorhinis gdl and m. pneumoniae fh have very high apparent activities of pyruvate dehydrogenase (pdh) (ec 1.2.4.1) and pyruvate dehydrogenase complex (pdhc). infection of normal and pdhc-deficient fibroblasts with these mycoplasma species resulted in a marked increase of the specific activity of these two enzymes, and under certain conditions could conceal the enzymatic defect. the non-fermentative mycoplasmas m. salivarium vv ... | 1984 | 6423397 |