Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [lung tissue alterations following experimental infection of mice with acholeplasmae isolated from simians with hematosarcoma]. | this paper is devoted to the study of pathogenic acholeplasmae potencies. two strains of acholeplasmae isolated from the blood and organs of papio hamadryas suffering from hemoblastosis and a standard ach. laidlawii a. strain were subjected to the comparative study with the use of a "pulmonary model" in experiments on mice. morphological investigations showed affections of the pulmonary tissue characterized by stage-by-stage inflammatory-destructive changes analogous to the lesions found in "myc ... | 1978 | 665035 |
| lipid compositional manipulation in acholeplasma laidlawii b. effect of exogenous fatty acids on fatty acid composition and cell growth when endogenous fatty acid production is inhibited. | a variety of potential inhibitors of de novo fatty acid biosynthesis have been tested for activity in acholeplasma laidlawii b. two compounds, avidin and n,n-dimethyl-4-oxo-2trans-dodecenamide (cm-55), an antimicrobial fatty amide, strongly inhibit de novo biosynthesis without nonspecific toxic effects at moderate dosages. avidin is the more potent inhibitor, abolishing de novo fatty acid synthesis and greatly reducing the chain elongation of exogenous fatty acids at level of 25 u/l. cm-55 gives ... | 1978 | 667693 |
| photodynamic inactivation and its repair in mycoplasmas. | photodynamic inactivation is the loss in viability observed when organic dye-treated cells are exposed to visible light and molecular oxygen. the photodynamic inactivation of mycoplasmas, the smallest free living cells, has been studied. depending on the extent of inactivation in acholeplasma laidlawii, photodynamic induced damage can be repaired if the irradiated cells are incubated in the dark in buffer. analysis of the dna of these cells shows that photodynamic inactivation induces single str ... | 1978 | 728473 |
| induction of a ph-stable interferon in sheep lymphocytes by mycoplasmatales virus mvl2. | the data presented in this report show that the enveloped mycoplasmatales virus mvl2 is capable of interferon induction in sheep peripheral blood lymphocytes. the phenomenon was dose dependent, requiring approximately 10(8) plaque-forming units of virus per 2 x 10(6) lymphocytes. the interferon was stable to ph 2.0 treatment, was produced in moderately high levels (greater than 1,000 units), and met many of the criteria for classification as a type i interferon. heat-inactivated mlv2 lost its ab ... | 1978 | 669793 |
| properties of a persistent viral infection: possible lysogeny by an enveloped nonlytic mycoplasmavirus. | mvl2, an enveloped double-stranded dna mycoplasmavirus, causes a nonlytic infection of acholeplasma laidlawii leading to the establishment of a persistent infection. persistently infected clones were found to be resistant to superinfection by homologous virus, but could be infected by heterologous virus. cells in a persistently infected culture had the potential to produce virus and transmitted this potential as a stable heritable trait. mitomycin c and uv light induced an increase in infectious ... | 1978 | 702650 |
| organometallic fatty acid and phospholipid analogs. synthesis and incorporation and detection in model membranes and biomembranes. | 1978 | 620019 | |
| growth and membrane lipid properties of acholeplasma laidlawii b lacking fatty acid heterogeneity. | 1978 | 643062 | |
| isolation of mycoplasma arginini from swine and from a swine waste disposal system. | mycoplasma arginini was isolated from the pharynges and tonsils of 4 of 6 swine necropsied during an epizootic of respiratory tract diseases and lameness. the organism was also isolated from 2 of 16 asymptomatic swine examined in the same herd approximately 10 months after the epizootic. in addition, m arginini, acholeplasma laidlawii, and other acholeplasmas were isolated from recycled effluent of an anaerobic lagoon used for disposal of waste from the swine herd. this observation represents th ... | 1978 | 677536 |
| rapid spectrophotometric determination of acholeplasma laidlawii membranes. | the amount of acholeplasma laidlawii membranes can be accurately, rapidly, and simply determined by spectrophotometric measurements after solubilization in 0.02 m sds, 0.02 m tris-hcl (ph 8.0). extinction coefficients from the 260- to 300-nm-absorption region are adequate for quantitative membrane determination. the following values were found: e1%1cm,280 = 9.11 +/- 0.63, e1%,s1cm,280 = 8.52 +/- 0.40 (corrected for light scattering), e1%1cm,280--310 = 8.15 +/- 0.35. the last value is the most sa ... | 1978 | 709438 |
| alteration by cereolysin of the structure of cholesterol-containing membranes. | when erythrocyte membranes were treated with cereolysin, negatively stained and examined by electron microscopy, ring and arc-shaped structures were observed in the membrane. the outside diameter of the rings varied from 33 to 50 nm with a border thickness of 6.7 to 8.3 nm. the arcs varied in length from 33 to 170 nm with a border thickness of also 6.7 to 8.3 min. when right-side-out erythrocyte ghosts which had been treated with cereolysin were examined by electron microscopy after freeze-fract ... | 1978 | 414780 |
| mechanisms of thermophily. | 1978 | 365460 | |
| bristol laboratories division, bristol-myers company, syracuse, n.y. | 1978 | 348086 | |
| acholeplasma laidlawii membranes: an electron spin resonance study of the influence on molecular order of fatty acid composition and cholesterol. | 1978 | 216314 | |
| acid-soluble nucleotides of acholeplasma (mycoplasma) laidlawii a. | a study was made of the acid-soluble nucleotides present in acholeplasma (mycoplasma) laidlawii a during growth. the nucleotide pool of this organism is meagre, both qualitatively and quantitatively. the main nucleotides are uridine mono- and diphosphates, and none of the more complex nucleotide compounds, such as uridine diphosphate (udp) sugars or sugar peptides, required for cell wall formation, were detected. the nucleotide composition of a. laidlawii a is compared with that of the streptoco ... | 1978 | 358744 |
| the nature and location of acholeplasma laidlawii membrane proteins investigated by two-dimensional gel electrophoresis. | the high resolution, two-dimensional electrophoresis system for the separation of proteins described by o'farrell, (o'farrell, p.h. (1975) j. biol. chem. 250, 4007--4021) has been modified for the separation of acholeplasma laidlawii proteins. reproducible protein patterns have been obtained from a. laidlawii cell, membrane and soluble protein preparations. the isoelectric focusing of membrane proteins was greatly improved by removing the bulk of the membrane lipid before solubilizing the protei ... | 1978 | 102346 |
| role of cholesterol in the action of cereolysin on membranes. | 1978 | 102256 | |
| membrane enzymes: artifacts in arrhenius plots due to temperature dependence of substrate-binding affinity. | for the membrane sodium-stimulated magnesium-adenosinetriphosphatase of acholeplasma laidlawii b both the vmax and km values in the michaelis equation very strongly with temperature. simulations of arrhenius plots show that an enzyme with a temperature-dependent km can yield a variety of arrhenius plot artifacts, most notably erroneous "breaks," if activity is assayed at a fixed substrate concentration. | 1978 | 146257 |
| size and shape of mycoplasma virus mv-lg-l 172 dna. | sedimentation of dna of mycoplasma virus mv-lg-l 172 in neutral and alkaline density gradients showed that the chromosome of this virus is most probably formed by a double-stranded circular dna molecule with a molecular weight of approx. 10(7) daltons. these results were confirmed by direct electron microscopy of the viral dna. gamma-irradiation of the virus caused in its dna single breaks on the average per each 66 ev of absorbed energy. virus survival depended exponentially on the irradiation ... | 1978 | 35941 |
| physiological role and membrane lipid modulation of the membrane-bound (mg2+, na+)-adenosine triphosphatase activity in acholeplasma laidlawii. | the membrane-bound adenosine triphosphatase (atpase) activity of acholeplasma laidlawii b differs in many respects from the common (mg2+, ca2+)-atpase activity of higher bacteria, most notably in that it is specifically activated by mg2+ and strongly and specifically stimulated by na+ (or li+). various inhibitors diminish the atpase activity with a concentration dependence which suggests that a single enzyme species is responsible for all of the observed atp hydrolytic activity (both basal and n ... | 1978 | 31351 |
| effect of ammonium ion concentration and osmotic pressure on growth of ureaplasma urealyticum (t-strain mycoplasma). | the effect of ammonium ion concentration and osmotic pressure on growth of ureaplasma urealyticum type viii was determined by using a well-buffered broth medium containing 10 mm urea. the addition of nh4cl to the medium at concentrations up to 10 mm did not affect growth; however, addition of larger quantities progressively decreased both the specific growth rate (mu) and the maximum yield of the culture, with concentrations of 80 mm completely inhibiting growth. addition of either 150 mm kcl or ... | 1978 | 26668 |
| symport h+/carbohydrate transport into acholeplasma laidlawii cells. | 1978 | 26600 | |
| fractionation of membrane proteins by hydrophobic interaction chromatography and by chromatography on agarose equilibrated with a water-alcohol mixture of low or high ph. | 1978 | 25906 | |
| in vitro antimycoplasmal activity of mepartricin. | the in vitro antimycoplasmal activity of mepartricin was evaluated on several mycoplasma strains. the results demonstrate that this polyene antibiotic possesses a high efficacy against these microorganisms. | 1979 | 118890 |
| mycoplasma contamination in cell culture of crohn's disease material. | 1979 | 89521 | |
| the pathogenicity of avian mycoplasmas. | based on literature data and own experiences the author gives an outlook about pathogenicity of avian mycoplasmas. in chickens and turkeys m. gallisepticum and m. synoviae (in addition to it m. meleagridis exclusively in turkeys) are the most important mycoplasmas producing respiratory disease, inflamation of synovial membranes and other lesions. their pathogenic effect is very much influenced by dose of agent, route of entry of microorganism, age of birds, virulence and tropism of organism as w ... | 1979 | 44612 |
| demonstration by electron microscopy of intracellular virus in acholeplasma laidlawii infected with either mv-l3 or a similar but serologically distinct virus (bn1 virus). | cultures of acholeplasma laidlawii strain m1305/68 were inoculated with mycoplasmatales virus-laidlawii 3 (mv-l3) and examined by electron microscopy. particles resembling mv-l3 were observed both intra- and extracellularly in thin sections prepared from mv-l3 infected cultures, but not from uninfected cultures. similar particles were occasionally observed in uninoculated cultures of a. laidlawii strain bn1 cells, from which a virus (bn1 virus) was subsequently isolated. this virus was morpholog ... | 1979 | 84856 |
| [glucose induced transport of h+, k+ and lactate in the cells of acholeplasma laidlawii]. | currents of h+ and k+ ions initiated under the effect of facultative anaerobe of a. laidlawii, valinomycin, nigericin and carbonyl cyanide chloride phenylhydrasone on the membrane are recorded by means of the system of cation sensitive electrodes. it is stated that during glucose transport a redistribution of h+ and k+ and lactate between the cellular content and the medium takes place. preincubation of cells with 3-o-methyl-d-glucose essentially decreases the effect of induced ion transport. it ... | 1979 | 35239 |
| the effect of high hydrostatic pressure on the membrane-bound atp-ase of acholeplasma laidlawii b [proceedings]. | 1979 | 160925 | |
| simplified preparation of mycoplasmas, an acholeplasma, and a spiroplasma for scanning electron microscopy. | a simple, effective procedure was developed for scanning electron microscopic examination of mycoplasmas and similar organisms. cultivation of several mycoplasmal species, an acholeplasma, and a spiroplasma in broth media in leighton tubes with cover slips resulted in attachment of the organisms to the cover slips. the attached cells were easily processed for either scanning electron microscopy or light microscopy. by eliminating the need for centrifugation, which was used in previously describe ... | 1979 | 370106 |
| comparative studies between microbiological culture and uptake of uridine/uracil to detect mycoplasmal infection of cell cultures. | 1979 | 376320 | |
| alteration of colonial morphology of acholeplasma laidlawii and acholeplasma modicum by infection with mycoplasmatales viruses. | morphologically aberrant colonies resulted from the infection of acholeplasma laidlawii with two of its three known viruses and from acholeplasma modicum cells naturally carrying virus. the patterns of colonial alteration differed between cells infected with the two a. laidlawii viruses. colonies derived from single cells infected with the bullet-shaped virus mv-l1 (mycoplasmatales virus-laidlawii-1) had a radial sectoring pattern of intracolonial swellings ("blebs"), whereas cells infected with ... | 1979 | 378947 |
| [action of mycoplasma arthritidis and acholeplasma laidlawii on the immunological reactivity of balb/c mice infected with the rauscher leukemia virus]. | 1979 | 389300 | |
| purification and properties of acetate kinase from acholeplasma laidlawii. | acetate kinase (ec 2.7.2.1) was purified from acholeplasma laidlawii cytoplasm by a combination of ammonium sulfate fractionation, gel filtration, diethylaminoethyl-cellulose chromatography, and affinity chromatography on 8-(6-aminohexylamino)-adenosine 5'-triphosphate conjugated to sepharose 4b. the enzyme was composed of polypeptide chains of about 50,000 molecular weight as estimated from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. under nondenaturating conditions, apparent mol ... | 1979 | 217865 |
| the ayerst award lecture 1978. organization and dynamics of membrane lipids as determined by magnetic resonance spectroscopy. | 1979 | 218704 | |
| activities of enzymes of purine and pyrimidine metabolism in nine mycoplasma species. | 1979 | 232630 | |
| studies on classification of acholeplasmas isolated from horses, cattle and abattoir sewage. | 1979 | 430937 | |
| [comparative study of rosette and plaque formation in rats infected with mycoplasma arthritidis and acholeplasma laidlawii]. | m. arthritidis suppresses rosette- and plaque-formation in rats infected with this strain of mycoplasma. on the 15th day the immune response was restored in the control and experimental groups of animals. in later stages a strong stimulation of rfc and pfc was recorded, which levelled on day 150. on the contrary, a. laidlawii stimulated rfc and pfc in all stages of infection. a relationship between the phenomena described and pathogenic properties of the mycoplasma is discussed. | 1979 | 380687 |
| physical characterization of the superhelical dna genome of an enveloped mycoplasmavirus. | mycoplasmavirus mvl2 is a nonlytic enveloped virion containing dna. this dna has been shown to be a double-stranded circular superhelical molecule of 11.8 kilobase pairs (7.8 x 10(6) daltons). the superhelix density is greater than that of phi x174 rfi but less than that of pm2 phage dna. a physical map of the mvl2 genome has been obtained using restriction endonucleases. | 1979 | 430595 |
| characterization of mycoplasmavirus mvl2 dna. | the size and molecular configuration of mycoplasmavirus mvl2 dna are presented. the dna was shown to be a covalently closed circular duplex molecule with a molecular weight of 7.4 x 10(6). in sucrose gradients at neutral ph, the form i and form ii dna molecules have sedimentation values of approximately 29s and 23s, respectively. under alkaline conditions, the form i and form ii have s values of 70 and 20, respectively. | 1979 | 430596 |
| the properties of gel state lipid in membranes of acholeplasma laidlawii as observed by 2h nmr. | 1979 | 437110 | |
| is the vertical disposition of mycoplasma membrane proteins affected by membrane fluidity? | the influence of the physical state of the membrane lipid matrix on the vertical disposition of membrane proteins was studied with acholeplasma laidlawii. changes in membrane fluidity were brought about by altering the fatty acid composition of membrane lipids, by changing the growth temperature, by aging of cultures and by inducing changes in the membrane lipid-to-protein ratio through treatment with chloramphenicol. the lactoperoxidase-mediated iodination technique was used to label membrane p ... | 1979 | 444513 |
| role of lipid fatty acyl composition and membrane fluidity in the resistance of acholeplasma laidlawii to complement-mediated killing. | 1979 | 448140 | |
| the use of the anti-acholeplasma activities of streptomyces culture filtrates for the screening of new antibiotics. | a screening method for new antimicrobial agents from streptomyces culture filtrates was developed. three different types of test organisms were used for determining the antimicrobial activities of the culture filtrates: they were (a) an antibacterial activity test against staphylococcus aureus, (b) an antimycoplasmal activity test against acholeplasma laidlawii, and (c) a cytotoxicity test against hela-s3 cells. the active filtrates showing antimicrobial spectra (anticellogram) which did not mat ... | 1979 | 462473 |
| on the interaction between intrinsic proteins and phosphatidylglycerol in the membrane of acholeplasma laidlawii. | 1979 | 464610 | |
| replication of mycoplasmavirus mvl51: vi. acriflavine stimulates growth of this single-stranded dna virus. | 1979 | 486185 | |
| lipid distribution in acholeplasma laidlawii membrane. a study using the lactoperoxidase-mediated iodination. | the lactoperoxidase-mediated radioiodination has been applied to study the transbilayer distribution of phospho- and glycolipids in acholeplasma laidlawii membranes. after radioiodination, about 5% of the 125i-iodine was found in membrane lipids. a comparison of the labeling intensities of the various lipid species between iodinated intact cells and isolated membranes revealed that the glycolipids monoglucosyldiglyceride and diglucosyldiglyceride are located almost exclusively in the outer half ... | 1979 | 486468 |
| prevalence of mycoplasmal bovine mastitis in california. | seven species of mycoplasma plus one or more unknown species were found to cause bovine mastitis in california. both the frequency of cases and number of species of mycoplasma in samples received at the laboratory have increased from 1976 to 1978. by survey, nearly 4% of samples of bulk tank milk from dairy farms were found to contain mycoplasma of potential pathogenic significance. acholeplasma laidlawii was frequently isolated from samples both from cows and from farm bulk tanks during wet, ra ... | 1979 | 507492 |
| carotenoids acts as reinforcers of the acholeplasma laidlawii lipid bilayer. | acholeplasma laidlawii cells grown with oleic acid produced much more colored carotenoids than did cells grown with elaidic acid. the amount of carotenoids was decreased 80 to 90% by growing the cells with 0.05 m propionate, resulting in a marked increase in the mobility of both 5-doxylstearate and 12-doxylstearate incorporated into the membranes. the fatty acid composition of the propionate-grown cells differed from that of cells grown without propionate by containing odd-numbered rather than e ... | 1979 | 533770 |
| unusual positional distribution of fatty acids in phosphatidylglycerol of sterol-requiring mycoplasmas. | 1979 | 510549 | |
| composition and molecular organization of lipids and proteins in the envelope of mycoplasmavirus mvl2. | mvl2 virus was purified from culture supernatants of infected acholeplasma laidlawii cells by differential centrifugation, followed by velocity centrifugation in sucrose gradients. the purified virus contained 0.08 to 0.1 mumol of lipid phosphorous per ml of viral protein. thin-layer chromatography of viral lipids revealed the presence of phospho-, glyco-, and phosphoglycolipids identical with those found in the host cell membrane, but the relative amount of phosphatidylglycerol was much lower t ... | 1979 | 513201 |
| [experience in identification and control of mycoplasma in dairy cattle stock under routine laboratory conditions]. | exacting demands have to be met by milk testing routine laboratories where mycoplasma species are to be cultured from milk samples. cleanliness of sampling, immediate cold storage, and no-delay transport of the milk samples to the testing centre are of greatest importance to the informative value of all mycoplasma tests. in the summer season, it is recommended to freeze the milk samples immediately after sampling. mycoplasma broth should not be inoculated to animals of the herd from which the sa ... | 1979 | 551756 |
| [acholeplasma laidlawii--a pathogenic or apathogenic species?]. | the question is discussed, whether acholeplasma laidlawii is a pathogenic or apathogenic species. studies have shown that it is a species of potential pathogenicity, however, with virulence properties differing greatly by strains. nothing so far has become known of contributive factors which might be needed for an infectious disease to develop. | 1979 | 551758 |
| [mycoplasma mastitis in cattle]. | reported in this paper are experiments from which the conclusion was drawn that acheloplasma laidlawii could cause changes in the mammary gland under certain circumstances. | 1979 | 551753 |
| lipid reorganization in biological membranes: a study by fourier transform infrared difference spectroscopy. | the first application of infrared difference spectroscopy to the study of a natural biological membrane is described. perdeuterated palmitic acid was incorporated biosynthetically into the lipids of the plasma membrane of acholeplasma laidlawii and the temperature-induced structural rearrangement of the endogenous lipids monitored via their c--2h vibrational modes. changes in infrared parameters were studied between 0 and 50 degrees c and contrasted with those occurring in the model membrane sys ... | 1979 | 760788 |
| fractionation of membranes from acholeplasma laidlawii a on the basis of their surface properties by partition in two-polymer aqueous phase systems. | acholeplasma laidlawii a consists of pleomorphic cell clusters surrounded by a single membrane. when lysed, a cell gives rise to several membrane fragments which cannot be separated from each other by isopycnic sucrose gradient centrifugation. a heterogeneous lateral organization of the cell membranes was detected by countercurrent distribution of membrane fragments in a two-polymer aqueous phase system. it revealed that the membranes consist of at least two subpopulations with respect to surfac ... | 1979 | 760784 |
| [studies of mycoplasma mastitis in cattle. 6. testing of mycoplasma isolated from milk for udder pathogenicity]. | strains of m. bovis, a. laidlawii, a. axanthum, and one unidentified strain of the family of mycoplasmataceae as well as altered secretion obtained from cows with mastitis were intracisternally applied in experiments and proved to be pathogenic to cattle udder. the results are likely to suggest the importance of mycoplasma isolated from the milk of mastitis cows to the aetiology of enzootic mastitis in three large dairy cattle stocks. intravenous application of m. bovis and a. laidlawii caused n ... | 1979 | 547918 |
| [studies of mycoplasma mastitis in cattle. 7. mycoplasma mastitis in 3 dairy cattle herds]. | reported in this paper is the occurrence of enzootic mastitis in three dairy cattle stocks. the outbreaks had been caused by mycoplasma bovis, acholeplasma laidlawii, acholeplasma axanthum as well as by one unidentified strain of the family of mycoplasmataceae. all animals with positive response to mycoplasma tests were identified an selected by repetitive testing of cultures in milk samples which had been taken from all lactating and dry cows and heifers as well as by evaluation of organ sample ... | 1979 | 547919 |
| comparison of mycoplasmatales virus mv-lg-ps2-l172 with plasmavirus mv-l2 and the other mycoplasma viruses. | mycoplasma virus mv-lg-ps2-l172 was sensitive to heat (56 degrees c/30 minutes), nonidet-p40 and ether. in these respects it resembled plasmavirus mb-l2. however, it differed from mv-l2 (and the other mycoplasma viruses, mv-l1, mv-l3 and bn1 virus) in reciprocal plaque inhibition and serum neutralization tests (mv-l2 only). by plaque formation on host lawns resistant to the different mycoplasma viruses, including mv-lg-ps2-l172, this latter virus was shown to be distinct from the other viruses, ... | 1979 | 518304 |
| [lipid regulation of carbohydrate transport system in mycoplasma]. | cultivation of acholeplasma laidlawii cells in media containing unsaturated fatty acids results in changes of the physiological state of the membrane lipid bilayer due to preferable incorporation of an unsaturated fatty acid into lipids. the lipids are capable to regulate the transport activity since the transport rates for glucose, 3-o-methyl-c-glucose, glucerol and erythritol change considerably when the cells are cultivated in media containing different unsaturated fatty acids. the transport ... | 1979 | 454709 |
| binding of lectins to membranes of mycoplasmas from aging cultures. | the binding of iodinated concanavalin a (con a) and ricinus communis agglutinin (rca) to intact cells and isolated membranes of acholeplasma laidlawii, mycoplasma hominis and mycoplasma capricolum decreased with the progression of the culture from the mid- to the late-logarithmic phase of growth. the binding of the lectins to acholeplasma laidlawii membranes had no significant effect on membrane fluidity, as assessed by electron-paramagnetic resonance spectroscopy of spin-labelled fatty acids, a ... | 1979 | 542135 |
| [studies of mycoplasma mastitis in cattle. 5. studies of udder pathogenicity of mycoplasma and acholeplasma strains of different origins]. | isolated acholeplasma laidlawii strains exhibited highly differentiated behaviours regarding their udder pathogenicity. twelve of 16 tested strains were pathogenic to udder. symptoms of acute udder inflammation were caused by all ten a. laidlawii strains isolated from differentiated material of calf, but by only two of six strains isolated from differentiated material of cattle. intracisternal instillation of both strains from milk and one strain each from udder skin or cervical mucus caused mer ... | 1979 | 547917 |
| studies on bacterial cell wall inhibitors. vi. screening method for the specific inhibitors of peptidoglycan synthesis. | a screening method was established for selecting new specific inhibitors of bacterial cell wall peptidoglycan synthesis. in the primary test, culture broths of soil isolates were selected based on relative microbial activity. a culture, to be retained, must be active against bacillus subtilis and lack activities against acholeplasma laidawii. in the secondary test, inhibitors of bacterial cell wall synthesis were identified by their ability to prevent the incorporation of meso-[3h]diaminopimelic ... | 1979 | 528376 |
| scanning electron microscopy of acholeplasma colonies on agar. | the colony formation and morphology of acholeplasma laidlawii and of an acholeplasma species was studied by scanning electron microscopy. in the colonies of both acholeplasma spp. large irregularly shaped cells, spherical cells, chains of beads, and long filaments with small bulbous distensions were seen. the membrane of some of the large cells seemed to be perforated, giving the cell a pitted appearance. | 1979 | 534959 |
| structural and biological properties of mycoplasmavirus mvl3: an unusual virus-procaryote interaction. | the kinetics of adsorption and growth of mycoplasmavirus mvl3 in acholeplasma laidlawii 1305/68 host cells have been studied with one-step growth, premature lysis, and single-burst experiments. the virus was found to kill infected host cells. virus release starts 90 min after infection and continues for about 10 to 15 h. hence, virus production is unlike the classical lytic bacteriophages and instead resembles nonlytic cytocidal animal viruses. structural details of the virus are described, and ... | 1979 | 541825 |
| selective killing of mycoplasmas from contaminated mammalian cells in cell cultures. | 1980 | 6156417 | |
| methylation patterns of mycoplasma transfer and ribosomal ribonucleic acid. | the methylation patterns of transfer and ribosomal ribonucleic acid (rna) from two mycoplasmas, mycoplasma capricolum and acholeplasma laidlawii, have been examined. the transfer rna from the two mycoplasmas resembled that of other procaryotes in degree of methylation and general diversity of methylated nucleotides, and bore particular resemblance to bacillus subtilis transfer rna. the only unusual feature was the absence of m5u from m. capricolum transfer rna. the methylation patterns of the my ... | 1980 | 6160144 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| dialogue between membranes and their lipid-metabolizing enzymes. | 1980 | 6768613 | |
| 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 |
| 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 |
| [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 |
| [polysaccharide participation in bacterial wall permeability]. | 1980 | 6773273 | |
| 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 |
| [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 |
| [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 |
| [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 |
| effects of charged cholesteryl esters on mycoplasma growth. | 1980 | 7215545 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |