| [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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| cell culture media: contamination at flow labs. | | 1983 | 6888532 |
| 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 |
| 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 |
| 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 |
| 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 |
| [immunologic and functional activity of the lymphocytes of mice infected with acholeplasma laidlawii and rauscher virus]. | | 1980 | 6988017 |
| 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 |
| distinguishing between mn-containing and fe-containing superoxide dismutases in crude extracts of cells. | | 1980 | 6994652 |
| [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 |
| [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 |
| 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 |
| [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 |
| a note on positive bactec readings produced by mycoplasma. | | 1981 | 7024236 |
| 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 |
| 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 |
| 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 |
| 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 |
| isolation of acholeplasma laidlawii from a giraffe (giraffa camelopardalis rothschildi) and a mouflon (ovis musimon). | | 1982 | 7064318 |
| 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 |
| 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 |
| isolation and identification of mycoplasmas from the respiratory tract of the white leghorn chicken in the sudan. | | 1982 | 7093655 |
| 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 |
| 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 |
| identification of iron- and phosphorus-containing antigens of the acholeplasma laidlawii cell membrane. | | 1982 | 7106296 |
| 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 |
| 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 |
| 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 |
| active diffusion of adsorbed mycoplasmal virus l3 on acholeplasma laidlawii cell membranes. | | 1982 | 7123047 |
| 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 |
| 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 |
| [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 |
| 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 |
| [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 |
| comparison of the ultrastructural aspects of acholeplasma laidlawii grown in liquid and solid media. | | 1982 | 7159213 |
| 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 |
| 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 |
| effect of molecular weight of polyethylene glycols on inactivation of mycoplasma pulmonis and acholeplasma laidlawii a. | | 1982 | 7186082 |
| isolation of mycoplasma from a buffalo (bubalus bubalis) with mastitis. | | 1981 | 7199239 |
| 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 |
| 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 |
| effects of charged cholesteryl esters on mycoplasma growth. | | 1980 | 7215545 |
| 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 |
| 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 |
| 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 |
| 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 |
| studies on acholeplasma laidlawii grown on branched-chain fatty acids. | | 1981 | 7259182 |
| effects of anesthetics on water permeability and lipid metabolism in acholeplasma laidlawii membranes. | the addition of tetracaine and diethyl ether to acholeplasma laidlawii at concentrations commonly used for local anesthesia did not affect water permeability over the cell membrane, as measured by a pulsed magnetic field gradient nmr method. however, a. laidlawii changed its membrane lipid composition upon treatment with these anesthetics. both tetracaine and diethyl ether addition resulted in a decrease in the molar ratio between the major membrane glucolipids, monoglucosyldiacylglycerol and di ... | 1981 | 7260084 |
| cytoplasmic helical structure associated with acholeplasma laidlawii. | a distinct spiral protein structure was found in three species of acholeplasma, but was not found in the mycoplasma species studied. the spirals, which are 14 nm in width and of variable length from 50 to 300 nm, are formed by a helical arrangement of 7-nm subunits. a rosette-like structure 45 nm in diameter also composed of 7-nm subunits was found in close association with the spirals and may be a taut in vivo form of the spiral. the electrophoretic profile in sodium dodecyl sulfate-polyacrylam ... | 1981 | 7263616 |
| detection of mycoplasmal contaminants in sera. | | 1981 | 7275992 |
| isolation and characterization of mycoplasma and acholeplasma from apparently healthy and diseased (infectious sinusitis) turkeys. | investigation of 136 turkeys (24 manifesting infra-orbital sinusitis, 112 apparently healthy) resulted in isolation of 79 strains of mycoplasma and 4 of acholeplasma. by the disc growth inhibition test with 16 reference antisera of avian serogroups, 55 strains were identified serologically and 28 remained unidentified. thirteen strains of mycoplasma gallisepticum, 1 of m. meleagridis, and 2 of acholeplasma laidlawii were isolated from turkey sinusitis whereas serogroups c (2), d (19), f (8), m. ... | 1981 | 7278710 |
| membrane structures of acholeplasma laidlawii and its virus. | the main types of ultrastructures found in the freeze-fracture faces of acholeplasma laidlawii s 2 and its virus mv-lg-l 172 were (1) particles 7-19 nm in diameter, mostly located in the convex cytoplasmic fracture faces. (2) small bulges or aggregates, 13-25 nm in diameter, which occupied only limited areas of both inner and outer fracture faces of some mycoplasmas, (3) numerous tiny grains and/or spikes 2-6 nm in diameter, protruding from a finely structured background, especially in the outer ... | 1981 | 7286852 |
| mycoplasma-virus contacts, budding and scars remaining in the membranes of acholeplasma laidlawii and its virus. | various stages of virus and mycoplasma budding indicated that both virus and, most probably some mycoplasma progeny developed by budding. besides this alternative, binary fission was the mode of mycoplasma reproduction. mycoplasma-virus and mycoplasma-mycoplasma connections by stems were observed. circular scars, 40-80 nm in diameter, often in groups, were left in the membrane of mycoplasmas by the budding bodies. cytoplasmic structures seen in cross-fraction are presented. a relatively small nu ... | 1981 | 7286853 |
| cholesterol transfer from normal and atherogenic low density lipoproteins to mycoplasma membranes. | the purpose of this study was to determine whether the free cholesterol of hypercholesterolemic low density lipoprotein from cholesterol-fed nonhuman primates has a greater potential for surface transfer to cell membranes than does the free cholesterol of normal low density lipoprotein. the low density lipoproteins were isolated from normal and hypercholesterolemic rhesus and cynomolgus monkeys, incubated with membranes from acholeplasma laidlawii, a mycoplasma species devoid of cholesterol in i ... | 1981 | 7295188 |
| protein composition and extractability of lipid-modified membranes from acholeplasma laidlawii. | membranes from acholeplasma laidlawii have been extracted with neutral detergents, which solubilize the proteins and lipids selectively, or with sodium deoxycholate, which gives an almost total solubilization. the amounts of individual proteins present in the detergent extracts of membranes with induced variations in lipid compositions were determined by crossed immunoelectrophoresis. extraction with the neutral detergent tween 20 showed that ionic lipids and the glucolipid diglucosyl diglycerid ... | 1981 | 7306495 |
| purification and characterization of nadh oxidase from membranes of acholeplasma laidlawii, a copper-containing iron-sulfur flavoprotein. | 1. nadh oxidase was extracted from the membranes of acholeplasma laidlawii with buffer containing 3% triton x-100 and subsequently purified by several chromatographic steps. the final preparation was essentially homogeneous as judged by gel electrophoresis under nondenaturing conditions. 2. the enzyme appears to be a copper-containing iron-sulfur flavoprotein (fmn:cu:fe:labile s = 1:1:6:6). the enzyme, containing a high fraction of hydrophobic amino acids, is composed of three subunits of molecu ... | 1981 | 7318830 |
| bovine genital mycoplasmosis. | infection, lesions and clinical significance of acheloplasmas, mycoplasma bovis and mycoplasma bovigenitalium in genital disease of cattle are described. a more detailed account is given of ureaplasma infections. acute and chronic forms of granular vulvitis in both field and experimental disease are described as well as the role of the organism in abortion. recovery rates of ureaplasma and mycoplasma from semen and preputial washings in bulls are outlined and their significance in disease is dis ... | 1981 | 7337908 |
| distribution of ureaplasmas in the urogenital tract of ewes. | | 1981 | 7344258 |
| control of membrane polar lipid composition in acholeplasma laidlawii a by the extent of saturated fatty acid synthesis. | the low level of endogenous fatty acid synthesis in acholeplasma laidlawii a strain ef22 was found to be caused by a deficiency of pantetheine in the lipid-depleted growth medium. by supplementing the oleic acid-containing medium with increasing concentrations of pantethein, saturated fatty acid synthesis was stimulated (having an apparent km of 5 microm for pantetheine) and the incorporation of endogenously synthesized fatty acids in membrane lipids increased markedly. furthermore, carotenoid b ... | 1980 | 7352994 |
| lipid chain order in acholeplasma laidlawii membranes. what does 2h nmr tell us? | | 1980 | 7353632 |
| lipid and protein composition and thermotropic lipid phase transitions in fatty acid-homogeneous membranes of acholeplasma laidlawii b. | the membrane composition and lipid physical properties have been systematically investigated as a function of fatty acid composition for a series of acholeplasma laidlawii b membrane preparations made homogeneous in various fatty acids by growing cells on single fatty acids and avidin, a potent fatty acid synthetic inhibitor. the membrane protein molecular weight distribution is essentially constant as a function of fatty acid composition, but the lipid/protein ratio varies over a 2-fold range w ... | 1980 | 7370250 |
| inactivation of mycoplasma in serum with binary ethyleneimine. | a method of inactivating mycoplasma contaminants in sera by using binary ethyleneimine was tried. when used at the concentration recommended for inactivating viruses, 0.001 m, binary ethyleneimine inactivated only two of five mycoplasma species. even at a concentration of 0.01 m, the compound did not consistently inactivate all mycoplasmas. | 1980 | 7372800 |
| colony morphology, ultrastructure and morphogenesis in mycoplasma hominis, acholeplasma laidlawii and ureaplasma urealyticum. | colonies of mycoplasma hominis, acholeplasma laidlawii (three strains) and ureaplasma urealyticum were examined by light and electron microscopy and their characteristic morphology, ultrastructure and morphogenesis are described. mycoplasma hominis and a. laidlawii, pg8 and oral strains, developed typical 'fried-egg' colonies which were remarkably heterogeneous in size. the colonies of a. laidlawii strain nctc 10116 were more homogeneous and grew mainly on the surface of the agar showing a fine ... | 1980 | 7373281 |
| ultrastructural study of the interaction between acholeplasma laidlawii and antibody. | the ultrastructure of agar-grown acholeplasma laidlawii incubated with specific antiserum or igm fractions of this antiserum has been investigated by the thin-sectioning technique. antiserum treatment resulted in the development of giant cells along the colony circumferences and in the coating of normal-size mycoplasmas with a periodically arranged extramembranous layer, consisting of attached immunoglobulins as shown by indirect immunoferritin labelling. the regular structure of the coat was no ... | 1980 | 7373282 |
| a survey of mycoplasma infections in domestic poultry. | a survey of mycoplasma infections of chickens, turkeys and ducks was made on tissues from a variety of sources and birds of various ages, and from pipped and dead-in-shell turkey embryos. the tissues examined consisted mainly of respiratory tissue and the cloaca and contents and also a small number of joint lesions and other tissues. from chickens, mycoplasmas were isolated from a total of 138 tissues with mycoplasma gallisepticum in preponderance. this was followed by m gallinarum, untyped orga ... | 1980 | 7375739 |
| phospholipid and cholesterol uptake by mycoplasma cells and membranes. | the ability of growing mycoplasma cells and their isolated membranes to take up exogenous phospholipids was correlated with their ability to take up cholesterol. horse serum or vesicles made of phosphatidylcholine and cholesterol served as lipid donors. growing cells of five mycoplasma species took up significant quantities of phosphatidylcholine and sphingomyelin as well as free and esterified cholesterol. in contrast, growing cells of three acholeplasma species failed to take up any of the exo ... | 1980 | 7388026 |
| isoenzymes in two species of acholeplasma. | the reference strains type a and type b and two equine strains of acholeplasma laidlawii were examined for a wide range of isoenzymes using thin-layer starch-gel electrophoresis; in addition two isoenzymes were examined in two strains of a. equifetale. the type strains a and b of a. laidlawii were differentiated by their lactate dehydrogenase, phosphoglucomutase and aspartate aminotransferase patterns and the two equine strains by their hexokinase, lactate dehydrogenase and phosphoglycerate kina ... | 1980 | 7391817 |
| lipid bilayer stability in membranes. regulation of lipid composition in acholeplasma laidlawii as governed by molecular shape. | the polar lipid composition in membranes of acholeplasma laidlawii is extensively regulated as a response to environmental changes. in particular, the ratio between the dominating lipids monoglucosyldiglyceride and diglucosyldiglyceride is altered depending on temperature, configuration of incorporated fatty acids, and membrane cholesterol content. synthesis of monoglucosyldiglyceride is stimulated by low temperature and saturated fatty acids but diminished by the presence of cholesterol. these ... | 1980 | 7407064 |
| orientational order of unsaturated lipids in the membranes of acholeplasma laidlawii as observed by 2h-nmr. | oleic acid specifically deuterated at fifteen different positions along the chain, including the double bond, was biosynthetically incorporated into the membrane lipids of the microorganism acholeplasma laidlawii b. a detailed study of the dynamic conformation of these chains was carried out using deuterium nuclear magnetic resonance. the deuterium spectra fourteen different samples were recorded as a function of temperature over the range 0-41 degrees c. spectra were obtained down to -52 degree ... | 1980 | 7407113 |
| the influence of the fatty acid composition of acholeplasma laidlawii membranes on the growth inhibitory activity of narasin, a polyether ionophorous antibiotic. | narasin, apolyether ionophorous antibiotic capable of acting as a transmembrane carrier of cations, has a growth inhibitory effect on acholeplasma laidlawii, permitting only 20% survival when present as 0.1 micrograms/ml in an undefined growth nutrient or fatty acid-deficient nutrient supplemented only with palmitic acid. when a. laidlawii is propagated in fatty acid-deficient nutrient supplemented with linoleic acid, however, the organisms become 40 times more sensitive to the growth inhibitory ... | 1980 | 7407129 |
| [blast transformation in response to plant mitogens in wistar rats infected with mycoplasma arthritidis or acholeplasma laidlawii]. | the response of lymphocytes of m. arthritidis- or a. laidlawii-infected rats to pha and cona was studied. mycoplasma infection was shown to stimulate the dna synthesis in lymphocytes of the spleen and lymph nodes and to depress the responses to mitogenes one week after infection. by the same time splenocytes of a. laidlawii-infected rats were shown to only slightly proliferate in response to pha. after 4 weeks of infection the lymphocyte transformation was greatly increased in both mycoplasma- a ... | 1980 | 7407377 |
| [chronic infection of acholeplasma laidlawii by a group l 1 mycoplasma virus]. | mycoplasma virus mvl 51, of the group l1 of gourlay, has been shown to induce a chronic cell infection of two reference strains (1305/68 and ja 1) of acholeplasma laidlawii. titers of virus and cells remain at a fairly high level during infection, around 10(8) units/ml, with a mean ratio of approximately 1 pfu/1 cfu, as under control of a regulation mechanism. however, sudden spontaneous variations in the virus level do occur, from time to time, thus suggesting transient regulation breaks but no ... | 1980 | 7407696 |
| membrane composition and virus susceptibility of acholeplasma laidlawii. | the membrane composition of 11 strains of acholeplasma laidlawii, including three strains persistently infected with mycoplasmaviruses mvl51, mvl2, and mvl3, was studied and correlated with mycoplasmavirus sensitivity. membranes of the strains had similiar sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns, and all strains were inhibited by an antiserum produced against membranes from one of the strains. the amounts of integral membrane proteins solubilized by the nonionic deterg ... | 1980 | 7410317 |
| aminopeptidase activity of acholeplasma laidlawii, mycoplasma bovirhinis, mycoplasma dispar and mycoplasma bovis. | aminopeptidase activity was demonstrated in extracts of acholeplasma laidlawii, mycoplasma bovirhinis, m. bovis and m. dispar. the enzyme specificity, which differed amongst the mycoplasma species examined, was characterized using 19 aminoacyl-beta-naphthylamides as substrates. the differences were detected after 4 h incubation with the substrates and potentially could be employed to aid in the characterization of certain mycoplasma species. | 1980 | 7411115 |
| virus and host cell dna syntheses during infection of acholeplasma laidlawii by mvl3, a nonlytic cytocidal mycoplasmavirus. | the replication of mycoplasmavirus mvl3 in acholeplasma laidlawii k2 host cells was studied by analysis of infected-cell lysates using sedimentation in sucrose gradients and dna-dna hybridization. viral dna replication was found to involve intermediates sedimenting faster than free viral dna, which is a linear, double-stranded molecule of about 26 x 10(6) daltons. after the shutdown of cellular dna synthesis, viral dna synthesis continued for many hours. the fate of cellular and parental viral d ... | 1980 | 7411689 |
| effect of cell membrane composition on the growth and composition of a nonlytic enveloped mycoplasmavirus. | | 1980 | 7414958 |
| [stimulation of hematopoiesis in mice inoculated with mycoplasma arthritidis]. | m. arthritidis is known to enhance the leukemogenic effect of rauscher leukemia virus in mice of different strains. as we have found earlier, m. arthritidis enhanced endogenous colony formation in irradiated mice. in this paper we made an attempt to establish a connection between these two phenomena. the mixed inoculation of balb/c mice with m. arthritidis and rauscher leukemia virus produced a great increase in the number of endogenous colonies as compared with the effect of mycoplasmas alone, ... | 1980 | 7415681 |
| ultraviolet, photodynamic and thermal inactivation of mycoplasmaviruses. | the ultraviolet light, photodynamic, and thermal inactivation parameters have been measured for the three groups of mycoplasmaviruses. the differences in these parameters for the three virus groups reflect differences in virion structure and in genome size and structure. | 1980 | 7421606 |
| methylated bases in mycoplasmal dna. | the dnas of four mycoplasma and one acholeplasma species were found to contain methylated bases. all of the five species contained 6-methyladenine (m6ade), the methylated base characteristic of prokaryotic dna. the extent of methylation of adenine residues in the mycoplasmal dna ranged from 0.2% in mycoplasma capricolum to about 2% in mycoplasma arginini and mycoplasma hyorhinis with intermediate methylation values for mycoplasma orale and acholeplasma laidlawii dnas. about 5.8% of the cytosine ... | 1980 | 7433124 |
| interaction of mycoplasma virus type 2 with cellular components of acholeplasma laidlawii strain ja1. | mycoplasma virus type 2 was shown to adsorb specifically to intact cells, membranes, and lipoglycan of acholeplasma laidlawii strain ja1 but not to these components of acholeplasma oculi. the oligosaccharide chain of the lipoglycan defined the specificity of the receptor site since deacylation not only did not reduce adsorption but increased it threefold. actual adsorption of virus to lipoglycan was demonstrated by sucrose density gradient separation of the virus-lipoglycan complex. a strain of ... | 1980 | 7441818 |
| adsorption, capping, and release of a complex bacteriophage by mycoplasma cells. | by electron microscopic studies, the adsorption and release of nonlytic, cytocidal mycoplasma virus mvl3, which infects acholeplasma laidlawii cells, have been examined. the mvl3 virion has a polyhedral head, collar, short tail, and tail fibers and contains linear double-stranded dna. adsorbed mvl3 virus showed a temperature-dependent clustering or capping on the mycoplasma cell membrane. during infection, a number of virus-cell membrane-related structures were observed, suggesting a general mod ... | 1980 | 7441822 |
| [stimulation of erythropoiesis in mice with mycoplasma infections]. | mycoplasma arthritidis was shown earlier to induce erythropoietin-independent erythropoiesis in infected mice. this study demonstrated the increased 59fe incorporation in the mouse spleen as early as day 4 after infection with m. arthritidis. it is known that inoculation of mice with low doses of actinomycin d (act d) results in a specific suppression of erythropoiesis without impairing the endogenous erythropoietin production. in this study the mice were injected with act d (80 microgram/kg bod ... | 1980 | 7448391 |
| giant cell formation in acholeplasma laidlawii, strain ja1. | striking alterations, which looked like blebs, were observed in colonies of acholeplasma laidlawii, strain ja 1. "craters" were seen on the surface of these colonies by scanning electron microscopy. in addition, giant cells of acholeplasma, up to 14 microns in diameter, i.e. approximately 20 times the size of a normal a. laidlawii cell, were visible in the colonies. the large forms were surrounded by a unit membrane. after infection with group 1 and group 2 mycoplasma-viruses, the proportion of ... | 1980 | 7467914 |
| 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 ... | 1995 | 7488623 |
| 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 ... | 1995 | 7496518 |
| 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 ... | 1995 | 7498064 |
| [oligodeoxyribonucleotides complementary to sections of the mollicute ribosomal operon as transcription inhibitors in vitro]. | antisense oligodeoxyribonucleotides have been studied for their effect on the transcription in vitro in mollicutes. a synthetic fragment of dna [symbol: see text] complementary to that part of dna which codes the 1510-1521 area of the 3'-terminal sequence 16s-prna of all mollicutes was used in the study as well as its modifications by imidasophenasine derivatives: [symbol: see text], [symbol: see text] [symbol: see text]. maximal inhibition of the mollicute transcription in vitro was observed wi ... | 1993 | 7517768 |
| phylogenetic classification of phytopathogenic mollicutes by sequence analysis of 16s ribosomal dna. | the phylogenetic relationships of 17 phytopathogenic mycoplasmalike organisms (mlos) representing seven major taxonomic groups established on the basis of mlo 16s ribosomal dna (rdna) restriction patterns were examined by performing a sequence analysis of the 16s rdna gene. the sequence data showed that the mlos which we examined are members of a relatively homogeneous group that evolved monophyletically from a common ancestor. in agreement with results obtained previously with other mlos, our r ... | 1994 | 7520735 |
| 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 ... | 1995 | 7537069 |
| efficient modulation of glucolipid enzyme activities in membranes of acholeplasma laidlawii by the type of lipids in the bilayer matrix. | it is generally anticipated, but so far not fully shown, that the physical properties of membrane lipid bilayers are governed by the concerted actions of the lipid-synthesizing enzymes. in the membrane of acholeplasma laidlawii a constant surface charge density, similar phase equilibria, and a nearly constant spontaneous curvature are maintained for the polar lipids. important for these properties are monoglucosyldiacylglycerol (mglcdag) and diglucosyldiacylglycerol (dglcdag), forming mainly rev ... | 1995 | 7577924 |