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organometallic fatty acid and phospholipid analogs. synthesis and incorporation and detection in model membranes and biomembranes. 1978620019
inhibition of interferon induction in mice by mycoplasmas and mycoplasmal fractions. 1978622377
[transport system for carbohydrates using a model of membrane vesicles from acholeplasma laidlawii cells]. 1978627681
disposition of phosphatidylglycerol in metabolizing cells of acholeplasma laidlawii. 1978631331
the planar distributions of surface proteins and intramembrane particles in acholeplasma laidlawii are differentially affected by the physical state of membrane lipids.we have studied the influence of changes in lipid organization on the planar distribution of two classes of membrane proteins: integral proteins which have amino groups exposed to labelling at the membrane surface by the biotinavidin-ferritin procedure, and those proteins which penetrate the lipid bilayer sufficiently to be seen as intramembranous particles by freeze-fracture electron-microscopy. when the membranes are examined at temperatures below the lipid phase transition, the first class is ...1978638151
membrane lipid metabolism in acholeplasma laidlawii a ef 22. influence of cholesterol and temperature shift-down on incorporation of fatty acids and synthesis of membrane lipid species.1. membrane lipid metabolism in acholeplasma laidlowii a ef 22 has been studied under different conditions by applying three different techniques for changing membrane viscosity: fatty acid and cholesterol supplementation and temperature changes. 2. the molar relationship between the two dominating membrane lipids, monoglucosyldiglyceride and diglucosyldiglyceride, is to a large extent determined by membrane viscosity properties. this is shown by the varying metabolic responses occurring during ...1978639825
growth and membrane lipid properties of acholeplasma laidlawii b lacking fatty acid heterogeneity. 1978643062
physico-chemical properties of phosphatidylglycerol in membranes of acholeplasma laidlawii. a study with phospholipase a2. 1978648516
sensitivites in vitro to antimicrobial drugs of bovine mycoplasmas isolated from respiratory and genital tracts.a total of 155 mycoplasma strains were examined for sensitivity to nine antibiotics and four nitrofurans by the agar dilution method. they consisted of 69 strains of mycoplasma bovirhinis, 33 strains of m. bovigenitalium, 49 strains of acholeplasma laidlawii and four strains of a. modicum isolated from the nasal secretions, tracheas and lungs of calves manifesting respiratory symptoms and from bovine genital tracts collected at a slaughterhouse. as a result, furamizole and mitomycin c showed the ...1978652043
the positional distribution of a series of positional isomers of cis-octadecenoic acid in phosphatidylglycerol from acholeplasma laidlawii b. 1978656453
[energetics of active carbohydrate transport into mycoplasma cells].possible energy supply pathways of active transport of non-metabolized 3-o-methylglucose (3-o-mg) into acholeplasma laidlawii cells are studied. 3-o-mg transport is sensitive to arsenate, inhibitors of glucolysis and membrane mg-dependent atpase (dicyclohexylcarbodiimide) and to uncoupling agents. it is suggested that glycolysis is the main energy source, which main enzymes are found in cell-free extracts. a. laidlawii cells are capable to glycolytic atp synthesis using glucose as a substrate bu ...1978656486
efficiency and specificity of the sequential extraction of membrane proteins of acholeplasma laidlawii with the neutral detergent tween 20. 1978658403
replication of mycoplasmavirus mvl51. v. in vivo synthesis of virus-specific proteins. 1978664226
[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 ...1978665035
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 ...1978667693
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 ...1978669793
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 ...1978677536
differences in incorporation of nucleic acid bases and nucleosides by various mycoplasma and acholeplasma species.eight species representative of the serological diversity of the mycoplasmatales were tested for their ability to incorporate radiolabeled nucleic acid precursors into acid-insoluble material. cultures in complex growth medium were centrifuged and resuspended in minimal essential medium (eagle). for acholeplasma laidlawii, labeling occurred mainly during the first 4 h of incubation, with substrate saturation at 20 micron. all organisms tested incorporated uracil, adenine, and guanine; none incor ...1978681280
the distribution of molecular classes of phosphatidylglycerol in the membrane of acholeplasma laidlawii.a double-label technique has been applied to study the distribution of different molecular classes of phosphatidylglycerol in the membrane of acholeplasma laidlawii. after growth on oleic acid, 16% of the total phosphatidylglycerol contains two oleic acid residues and 84% contains one oleic acid and one saturated fatty acid. the dioleoyl phosphatidylglycerol is present in equal amounts in the outer and the inner layer of the membrane. phosphatidylglycerol which is associated with membrane protei ...1978687626
a severe outbreak of bovine mastitis assoicated with mycoplasma bovigenitalium and acholeplasma laidlawii.an outbreak of clinical mastitis is described in which 75 cows of a herd of 200 friesian cows were affected in one or more quarters over a period of three months. sixty animals failed to return to normal despite various intramammary and systemic antibiotic treatments. heifers, dry cows and lactating animals were affected. the milk of 15 out of 53 animals tested yielded mixed cultures of mycoplasma bovigenitalium and acholeplasma laidlawii. thirteen of 34 sera showed evidence of antibodies to a l ...1978695253
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 ...1978702650
water binding and phase structures for different acholeplasma laidlawii membrane lipids studied by deuteron nuclear magnetic resonance and x-ray diffraction.water binding capability and phase structures for different lipid species extracted from acholeplasma laidlawii a membranes have been studied using deuteron nuclear magnetic resonance and low-angle x-ray diffraction. the dominating membrane lipids are monoglucosyldiglyceride and diglucosyldiglyceride and each of them takes up limited amounts of water (bound plus trapped), i.e., up to 13% (w/w), whereas the phospholipids and phosphoglycolipids have larger hydration capacities. addition of magnesi ...1978708724
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 ...1978709438
crossed immunoelectrophoresis, in the presence of tween 20 or sodium deoxycholate, of purified membrane proteins from acholeplasma laidlawii.five membrane proteins from acholeplasma laidlawii have been previously purified on a large scale. these proteins have been used to establish the relationship between the precipitation lines obtained by crossed immunoelectrophoresis of solubilized cell membrane proteins from a. laidlawii in the presence of the neutral detergent tween 20 or those obtained in the presence of the anionic detergent sodium deoxycholate. this relationship, which was unambiguously established for four of the five prote ...1978711668
disposition of membrane proteins as affected by changes in the electrochemical gradient across mycoplasma membranes. 1978718682
cholesterol uptake is dependent on membrane fluidity in mycoplasmas.the transfer of elaidate-enriched acholeplasma laidlawii cells in culture from 37 degrees c to 4 degrees c virtually arrested exogenous cholesterol incorporation into the cell membrane. cholesterol uptake continued, though at a slower rate, in oleate-enriched a. laidlawii cells undergoing similar temperature shift-down. it is concluded that the incorporation of exogenous cholesterol into the cell membrane of living mycoplasmas is rapid when the membrane lipid bilayer is in the liquid-crystalline ...1978718901
effect of acriflavine on ultraviolet inactivation of acholeplasma laidlawii.an increased sensitivity to inactivation was observed when ultraviolet light-irradiated acholeplasma laidlawii cells were plated on medium containing either acriflavine or chloramphenicol. chloramphenicol reduced liquid holding recovery (dark repair) to about 10% of that in untreated irradiated cells. in acriflavine treated cells no dark repair could be observed and there was a progressive degradation of cell dna during holding. while the primary effect of acriflavine may be to inhibit excision ...1978718990
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 ...1978728473
[structural study of mycoplasma by a scanning electron microscopy method].scanning electron microscopy was applied to the study of mycoplasma arthritidis, myc. gallisepticum, and acholeplasma laidlawii. small spherical elements (0.3--0.5 micrometer) formed a reticular "framework" of the colonies in which larger (1--1.5 micrometer) spheroid or irregular-shaped cells (in case of myc. gallisepticum) and also rod-shaped (1--3 micrometer), filamentous (3--5 micrometer) forms and "large bodies" (5 x 3--8 x 3.5 micrometer) were located. apparently the latter represented cong ...1978747025
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 ...1979760784
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 ...1979760788
lipid-lipid and lipid-protein interaction in model systems and membranes. 1975769638
simple method for immunofluorescent identification of mycoplasma colonies.general purpose rubber stoppers proved to be a simple, rapid, and satisfactory method of transferring mycoplasma colonies from agar to microscope slides for immunofluorescence.1976770501
experimental mycoplasma mastitis in mice.thirteen strains of mycoplasma representing six different species, acholeplasma laidlawii, mycoplasma dispar, m. bovirhinis, m. bovigenitalium, m. agalactiae subsp. bovis, and m. mycoides subsp. mycoides, were inoculated into the mammary glands of mice, and the number of mycoplasmas present in the glands three days after inoculation was determined. the predominant response included involution of inoculated glands and a neutrophil infiltration. with the exception of m. dispar, the pathogenicity o ...1976776833
ultrastructural visualization of anionic sites on mycoplasma membranes by polycationic ferritin.anionic sites on mycoplasma membranes were visualized in the electron microscope by a polycationized ferritin derivative. the technique of thin sectioning was used. staining prior to fixation led to clustering of ferritin granules on the mycoplasma cell surface. on glutaraldehyde-fixed mycoplasma mycoides subsp. capri, m. gallisepticum, m. pneumoniae, and acholeplasma laidlawii, the anionic sites were uniformly distributed over the entire membrane surface. m. hominis did not bind the polycationi ...1976776936
binding of plant lectins to mycoplasma cells and membranes.the binding of iodinated wheat germ agglutinin, ricinus communis agglutinin, and concanavalin a to mycoplasma cells and membranes was examined. all mycoplasmas studied specifically bound concanavalin a or r. communis agglutinin and, to a lesser degree, wheat germ agglutinin. the binding of lectins to whole cells was similar to that recorded for membranes, suggesting that significant binding only occurred on the outer surface of the mycoplasma membrane. proteolysis of the membrane almost always ...1976789327
isoelectric focusing of mycoplasma proteins.polyacrylamide gel isoelectric focusing (pagif) in thin layer was used to resolve proteins of mycoplasma spp., acholeplasma spp., and eight strains of ureaplasma urealyticum (t-strain). a mixture of urea, triton x-100, and dithioerythritol was used to solubilize sonically disrupted cells. pagif was performed in the range of ph 3 to 10. protein patterns were carefully compared, demonstrating resolved and distinguishable species-specific protein bands. the eight serotypes of u. urealyticum (t-stra ...1976791125
interaction between tetanolysin and mycoplasma cell membrane.1. a partially purified tetanolysin preparation lysed the sterol-requiring mycoplasma capricolum cells but had no effect on m. capricolum cells adapted to grow with no or very little cholesterol. the sterol-non-requiring acholeplasma laidlawii cells grown either in a cholesterol-rich or a cholesterol-poor medium were unaffected by the tetanolysin preparation. 2. the lysis of m. capricolum cells by the tetanolysin preparation was temperature dependent, inhibited by cholesterol, sublytic concentra ...1976793633
cholesterol incorporation into bacterial membranes.the wall-covered bacteria micrococcus lysodeikticus, bacillus megaterium, and proteus mirabilis incorporated exogenous cholesterol into their cytoplasmic membrane in quantities resembling those incorporated by sterol-nonrequiring mycoplasmas. cholesterol incorporation into the outer membrane of p. mirabilis was much more restricted than into the cytoplasmic membrane.1975809427
inactivation of mycoplasmas by use of phenol, formalin and beta-propiolactone. 1976819443
[the importance of mycoplasma in infectious processes (author's transl)].mycoplasma pneumoniae, the pathogen responsible for primary atypical pneumonia, has appeared more frequently in recent years. while t-mycoplasma and mycoplasma hominis are found in greater numbers both in nonspecific urethritis and also in the genital flora, t-mycoplasma may also cause the formation of vesical calculi in animal experiments. mycoplasma can also be cultured from joint fluids, tumors and from blood samples from parturient women immediately after the birth.1976819817
microbiological assay of thiopeptin in broiler rations. 1977833096
[bovine mastitis caused by acholeplasms laidlawii]. 1977836266
acholeplasma laidlawii infection by group 3 mycoplasmavirus. 1977841870
host cell and ultraviolet reactivation of ultraviolet-irradiated mycoplasmaviruses.the mycoplasma acholeplasma laidlawii was shown to have mechanisms for both host cell and ultraviolet (uv) reactivation of uv-irradiated mycoplasmaviruses. host cell reactivation was examined by comparing the survival abilities of uv-irradiated double-stranded deoxyribonucleic acid mycoplasmavirus plated on both untreated and on acriflavine-treated cells. acriflavine treatment inhibited cell exision repair. decreased survival on the acriflavine-treated cells demonstrated host cell reactivation. ...1977845120
[characterization of acholeplasma strains by horizontal polyacrylamide flat gel electrophoresis (author's transl)].proteins extracted with phenol-acetic acid-water (2:1:0.5, w/v/v) from acholeplasma laidlawii (pg 8), a. granularum (bts-39), a. oculi (19l), a. modicum (pg 49), a. axanthum (s743) and the acholeplasma strains c1 and c112 (which were isolated from aborted horse foetuses) were compared by electrophoresis in horizontal acidic polyacylamide flat gel using the electrophoresis equipment lkb multiphor 2117. in this system the gels are not prepared in the electrophoresis chamber but between glas plates ...1977848216
the removal of the neutral detergent tween 20 from solubilized membrane proteins of acholeplasma laidlawii and other proteins by agarose-suspension electrophoresis. 1977848738
control of fatty acid composition of acholeplasma laidlawii membranes.the temperature-dependent pattern of incorporation of palmitate and oleate from the growth medium into acholeplasma laidlawii membrane lipids correlates with the physical state of the membrane defined by calorimetry. both the pattern and the state can be changed at will by changing the fatty acid composition of the membrane lipids. the ratio of palmitate to oleate incorporated is independent of temperature when the membrane bilayer is below its transition and fully ordered, but becomes temperatu ...1977851532
[some biochemical properties of acholeplasma laidlawii mutants defective in glucose carrier].some membrane properties of glucose transport system of acholeplasma laidlawii mutants uncapable of uptaking glucose as well as those of its non-metabolizing analogue, 3-0-methylglucose are studied. in contrast to the wild strain the mutant ptl-s cells fail to uptake carbohydrates with the saturation. there is no competition between carbohydrates during transport in this mutant no sugar exit is observed, and the sensitivity of transport to thiol reagents and pronase b is considerably affected. a ...1977851551
[study of the initial parasitic relationship between a virus of the gourlay group l 1 and the cellular population of acholeplasma laidlawii].the study of the relationship between mvl 51 virus, of the gourlay group l 1, and the mycoplasma cells of a. laidlawii during the first 35 min of infection leads to the conclusion that a "carrier state" has been established, free virus as well as infected and noninfected cells being present at the same time in the cultures. the evidence of a virus growth after 20 min of infection and the high level of remaining viable cells (1.15 x 10(8) cfu) at the end of the experiment also indicate that the c ...1977856420
[basic evidence for the active transport of carbohydrates in the membrane vesicles of acholeplasma laidlawii cells].a. laidlawii membrane vesicles are able to accumulate c14-glucose as well as maltose and fructose against the concentration gradient in the absence of exogeneous entergetic sources. sugar transport is inhibited by anaerobiosis and by the electron transfer inhibitors such as rotenone and amytal, and by proton conductors such as carbonylcyanide-m-chlorophenylhydrazone. arsenate and dicyclohexylcarbodimide (inhibitor of membrane-bound atpase) do not inhibit the sugar transport. it is concluded that ...1977861265
qualitative and quantitative variations of membrane lipid species in acholeplasma laidlawii a.in acholeplasma laidlawii a, strain ef 22, the relative amounts of the membrane polar lipids vary as a consequence of different fatty acid supplements to the growth medium. the number of lipid species also varies; a new apolar monoglucolipid containing four fatty acid residues was present only when saturated fatty acids dominated in the growth medium. a new phosphoglucolipid, probably with a glycerophosphoryl-monoglucosyldiglyceride structure, was also found. the most pronounced variations occur ...1977870042
reduction in cellular tumorigenicity after mycoplasma infection and elimination of mycoplasma from infected cultures by passage in nude mice. 1977872095
phospholipid requirement of the membrane-bound mg2+-dependent adenosinetriphosphatase in acholeplasma laidlawaii. 1977884075
effect of a. laidlawii on murine and human lymphocyte cultures.heat-inactivated a. laidlawii (al) was found to be a potent mitogen for mouse spleen cells. spleen cells from homozygous nude mice and spleen cells treated with anti-theta serum and complement responded as well as their respective controls, indicating that al represented a b-cell mitogen for mouse spleen cells. spleen cells from lps-unresponsive c3h/hej mice responded well to al. the peripheral blood leucocytes from unselected human donors were also stimulated by al, which appeared to represent ...1977891034
a continuous spectrophotometric assay for membrane-bound lysophospholipases using a thioester substrate analog. 1977891946
a mycoplasma mutant resistant to lysis by c: variations in membrane composition and altered response to the terminal c complex. 1977894046
[serum proteins in preparations of mycoplasma cells]. 1977899444
the lytic effect of lysolecithin on acholeplasmas and mycoplasmas.lysolecithin exhibits a lytic activity on acholeplasmas and mycoplasmas. the acholeplasmas studied, viz. acholeplasma laidlawii a and b, were found less susceptible than were the mycoplasmas, viz. mycoplasma gallisepticum and m. pneumoniae. the sensitivity to lysis was found to differ according to species, growth temperature and number of organisms used. variations in age of the population and the concentration of bivalent ions in the test medium had but little influence. the greatest lytic acti ...1977899794
membrane lipid biosynthesis in acholeplasma laidlawii b. relationship between fatty acid structure and the positional distribution of esterified fatty acids in phospho- and glycolipids from growing cells. 1977900942
membrane lipid biosynthesis in acholeplasma laidlawii b. investigations into the in vivo regulation of the quantity and hydrocarbon chain lengths of de novo biosynthesized fatty aicds in response to exogenously supplied fatty acids. 1977900943
membrane lipid metabolism in acholeplasma laidlawii a during normal and temperature-shift-down conditions [proceedings]. 1977902894
antibodies to acholeplasma laidlawii membrane lipids in normal guinea pig serum.acholeplasma laidlawii is killed and lysed by fresh normal guinea pig serum (gps) without additional antibodies. prior incubation of gps with whole a. laidlawii organisms abolishes the killing activity of gps. in the present study it was demonstrated that antibodies are present in normal gps. the classical pathway, not the alternative pathway, of the complement sequence was activated by these antibodies in fresh normal gps. the antibodies in gps belong to the igg class of immunoglobulins. they a ...1977908614
specific interaction of concanavalin a with glycolipid monolayers.the effect of 131i-labelled concanavalin a on the surface pressure and surface radioactivity of monolayers formed from phospholipids and from natural and synthetic glycolipids has been studied. the lectin binds to and penetrates dipalmitoyl phosphatidylcholine monolayers at a surface pressure of 15 dynes/cm and this interaction is inhibited by the presence of alpha-methyl mannose in the subphase. at surface pressures of 25 dynes/cm or higher, concanavalin a will interact with monoglucosyl diglyc ...1977911832
membrane lipid biosynthesis in acholeplasma laidlawii b: incorporation of exogenous fatty acids into membrane glyco- and phospholipids by growing cells.the extent of incorporation of a wide variety of exogenous saturated, unsaturated, branched-chain, and cyclopropane fatty acids into the membrane lipids of acholeplasma laidlawii b was systematically studied. within each fatty acid class the extent of incorporation generally increased markedly with increasing chain length, reached a maximum, and then declined progressively but less sharply with further increases above that chain length giving maximal direct incorporation. certain shorter-chain m ...1977914776
membrane lipid biosynthesis in acholeplasma laidlawii b: de novo biosynthesis of saturated fatty acids by growing cells.the de novo biosynthesis of fatty acids of 12 to 18 carbons from precursors of 5 carbons or fewer has been demonstrated in acholeplasma laidlawii b. radiolabeling experiments indicated that the normal primers for the synthesis of the even- and odd-chain fatty acids are acetate and propionate or valerate, respectively. saturated straight-chain monomethyl-branched fatty acids of up to five carbons were readily utilized as primers, wheras more highly branched species and those possessing halogen su ...1977914777
cholesterol-phosphatidylcholine dispersions as donors of cholesterol to mycoplasma membranes.growing cells of sterol-requiring mycoplasma hominis and sterol non-requiring acholeplasma laidlawii were used to test the ability of cholesterol-dipalmitoyl phosphatidylcholine dispersions to serve as cholesterol donors to these organisms. dispersions with high cholesterol to phosphatidylcholine ratios were more effective than dispersions with low cholesterol to phosphatidylcholine ratios in donating cholesterol to the membranes of both mycoplasmas and in promoting growth of the sterol-requirin ...1977921974
mycoplasma-dependent activation of normal lymphocytes: mitogenic potential of mycoplasmas for mouse lymphocytes.nonviable preparations of a wide variety of glucose-utilizing mycoplasma species, including acholeplasma laidlawii and spiroplasma citri, were found to be mitogenic for mouse lymphocytes. particularly strong reactions were obtained with mycoplasma synoviae, m. gallisepticum, m. pneumoniae, s. citri, and a strain of m. fermentans that was previously isolated from a leukemic patient. nonviable preparations of arginine-utilizing mycoplasmas inhibited the uptake of [3h]thymidine by lymphocytes, but ...1977924676
pathogenicity of certain mycoplasma species in the bovine mammary gland.strains of three of the species of mycoplasmas isolated from pneumonic calf lungs, mycoplasma dispar, mycoplasma bovirhinis and acholeplasma laidlawii, were inoculated into the bovine mammary gland. pathogenicity of the species was monitored by counting the inflammatory cells and mycoplasmas in milk. six of the seven m dispar strains produced clinical mastitis, but the seventh strain, vic12, was apparently avirulent. the four strains of m bovirhinis caused subclinical mastitis. none of the four ...1976935661
in vitro anti-mycoplasmal activity of amphotericin b methyl ester.the polyene macrolide antibiotic amphotericin b (ab) and its chemically modified derivative amphotericin b methyl ester (ame) were tested for in vitro activity against acholeplasma laidlawii, spiroplasma citri and mycoplasma gallisepticum. both polyene macrolide preparations demonstrated anti-mycoplasmal activity. however, ame was mycoplasmacidal toward all three strains of mycoplasma at levels which previous studies have indicated would be permissible for most cell culture systems, whereas the ...1976950321
characterization of an acholeplasma laidlawii variant with a rep- phenotype.an acholeplasma laidlawii variant has been isolated that has a rep- phenotype. the properties of this variant, relative to parental cells, are: (i) it exhibits no change in cell growth kinetics; (ii) it does not propagate single-stranded deoxyribonucleic acid (dna) mycoplasmaviruses but does propagate double-stranded dna mycoplasmaviruses; (iii) it converts parental circular single-stranded mycoplasmavirus dna to double-stranded replicative forms that are not replicated further; (iv) it exhibits ...1976956119
lysis of acholeplasma laidlawii by antibodies and complement.membranes of acholeplasma laidlawii were used to determine the membrane components involved in immune lysis and to eventually detect enzymatic changes in the membrane components during this reaction. in a previous publication we reported that a. laidlawii can be killed by antibody and complement and that antibodies to membrane proteins are by far more effective than antibodies to membrane lipids in the complement-dependent killing of this organism. in this report we demonstrate that membrane dam ...1976971945
[isolation and characteristics of an acholeplasma laidlawii mutant with defective carbohydrate transport]. 1976976034
on the possible role of respiratory activity of acholeplasma laidlawii cells in sugar transport.1. out of 20 exogeneous substrates only ethanol and, to a much lesser extent, lactate and pyruvate were shown to be capable of stimulating the respiration of acholeplasma laidlawii cells. however, none of these substrates changed the initial rate of active transport of 3-o-methyl-d-glucose (3-o-mg). 2. from inhibitory analyses and spectroscopic data, it is apparent that the respiratory chain of a. laidlawii has no cytochromes and is probably not responsible for oxidative phosphorylation. 3. vali ...1976984999
induction of interferon in ovine and human lymphocyte cultures by mycoplasmas.mycoplasma pneumoniae, acholeplasma laidlawii, m. arthritidis, and m. pulmonis were shown to induce interferon in the lymphocyte fraction of ovine peripheral blood leukocytes, but not in the polymorphonuclear leukocyte fraction. human peripheral blood lymphocytes produced significant levels of interferon in response to infection with m. pneumoniae and m. synoviae. the antiviral substance induced by the mycoplasmas in human lymphocytes was characterized as interferon by the usual criteria.1976985808
purification of the reduced nicotinamide adenine dinucleotide dehydrogenase from membranes of acholeplasma laidlawii.the ethanol-extracted respiratory chain-linked nadh dehydrogenase of acholeplasma laidlawii has been purified 25-35-fold. this purification involved delipidation of the ethanol-extracted minute non-sedimentable membrane fragments by detergent treatment and gel filtration on bio-gel p-200. sodium deoxycholate-sucrose density gradient centrifugation was followed by dialysis of the active nadh dehydrogenase fractions which caused flocculation of 60% of the membrane proteins while the nadh dehydroge ...1976990315
replication of mycoplasmavirus mvl51. iii. identification of a progeny viral dna-protein intermediate.intracellular replication of the non-lytic single stranded circular dna mycoplasmavirus mvl51 has been shown to involve three dna intermediates: rfi, rfii and ssi. growth in eagle's basal medium, rather than richer tryptose medium, has allowed the identification of an intermediate between nascent progeny chromosomes (ssi) and mature virus. this intermediate is a protein associated form of ssi.1976994855
acholeplasma laidawii mutant defective in glucose transport system. 19761001438
the influence of lipid state on the planar distribution of membrane proteins in acholeplasma laidlawii. 19761003469
[lipid composition of acholeplasma laidlawii cells].lipid composition of the cells of acholeplasma laidlawii was studied by column and thin layer chromatography. lipids of the cells contain phospholipids (41.3%), glycolipids (28%) and neutral lipids. phospholipids are represented by monoacylglycerophosphoryldiglucosyldiglyceride, glycerophosphoryldiglucosyldiglyceride, phosphatidylglycerine and phosphatidic acid. glycolipids contained diglucosyldiglyceride and monoglucosyldiglyceride. the content of cholesterine was low (1.3%) while the content o ...19761004257
[3-o-methl-d-glucose transport system in the cells of acholeplasma laidlawii].in cells of acholeplasma laidlawii a constitutive system of transport of glucose derivate 3-o-methyl-d-glucose was found. this derivate penetrated into cells, without modification and accumulated in free state. the transport system was of enzymatic nature and exhibited sharp substrate specificity. the transport of 3-o-methyl-d-glucose was an active process and occurred against the concentrated gradient.19761025884
topological features of membranes from staphylococcus aureus and acholeplasma laidlawii.topological and ultrastructural features of membranes from walled and wall-less bacterial cells were compared by examining membranes from staphylococcus aureus and acholeplasma laidlawii. osmotic lysis of protoplasts of s. aureus or cells of a. laidlawii produced membrane vesicles or large membrane fragments, but alumina grinding or sonication of these protoplasts or cells produced much smaller particles whose morphologic origin was difficult to determine. disrupted membranes from either organis ...19761026851
spread and control of mycoplasmal infection of cell cultures.environmental sampling was performed during trypsinization and passage of 3t-6 cell cultures that contained a mean of 4.3 x 10(7) colony forming units (cfu) per ml supernatant of a. laidlawii. the lip of the culture flask and the outside of the used pipet were always heavily contaminated. the outside of the culture flask (3/7), the work surface (8/12) and the outside of a pan of disinfectant (4/5) were regularly contaminated with mycoplasmas. airborne mycoplasmas were detected eight of 32 times ...19761034618
replication of mycoplasmavirus mvl51: attachment of mvl51 parental dna to host cell membrane.the replication of the single-stranded circular dna of mvl51 mycoplasmavirus has been studied with respect to the roles of free and membrane-associated viral dna intermediates. replication involves the formation of parental replicative intermediate (rf) molecules on, at most, two to three membrane sites per cell, symmetric rf replication at the membrane and apparent asymmetric rf replication in the cytoplasm leading to single-stranded progeny chromosomes.19761064049
recent progress in mycoplasma research.today, 12 years after the identification of eaton agent as a mycoplasma, much new information on this infection has accumulated. better methods have become available, which will be helpful in determining whether other mycoplasmas might be human pathogens, e.g., some ureaplasmas in nongonococcal urethritis. experimental mycoplasma infections in birds and animals have revealed common features with immune complex diseases in man. they may serve, therefore, as useful models for human mycoplasma dise ...19751081171
survival of frozen mycoplasmas.cooling to -70 c killed a higher percentage of acholeplasma laidlawii and mycoplasma mycoides var. capri cells than cooling to -20 c. however, to preserve cell viability for prolonged periods storage at -70 c was much more preferable. the percentage of cells surviving freezing could be increased by increasing the initial cell concentration or by the addition of dimethyl sulfoxide or glycerol as cryoprotective agents. in the presence of 1.5 m of any one of these agents survival rates of up to 100 ...19751099985
phase transitions and fluidity characteristics of lipids and cell membranes. 19751103214
mycoplasma species recovered from the reproductive tracts of western canadian cows.samples of cervico-vaginal mucus from 633 animals from 110 herds were cultured and yielded the following mycoplasmas: t-strain--88: mycoplasma bovigenitalium--79, mycoplasma spp. (leach group 7)--7, acholeplasma laidlawii--4, mycoplasma bovirhinis--2 and one not typable. uterine exudates and endometrial scrapings from 80 infertile cows in two herds were examined. four animals were positive, m. bovigenitalium was isolated three times, a. laidlawii and mycoplasma arginini once each. sixty-five nor ...19751125831
drying and irradiation of calf and horse serum. ii. influence on mycoplasma content of the calf sera.drying of calf sera produced only a negligible change in their content of acholeplasma laidlawii organisms and reduced the content of mycoplasma arginini organisms by 2 to 4 logs. gamma-irradiation of liquid and dried calf sera killed m. arginini and a. laidlawii organisms at irradiation levels of 0.2-0.3 and 0.4-0.6 mrads, respectively.19751179873
replication of mycoplasmavirus mvl51: i. replicative intermediates. 19751180927
molecular order in acholeplasma laidlawii membranes as determined by deuterium magnetic resonance of biosynthetically-incorporated specifically-labelled lipids.the first application of deuterium magentic resonance of specifically labelled lipids to the study of a natural biological membrane is described. palmitic acid labelled at the terminal methyl group with deuterium was incorporated biosynthetically into the lipids of the plasma membrane of acholeplasma laidlawii. the deuterium nuclear magnetic resonance spectra contain quadrupole splittings which yield directly order parameters for this region of the membrane. below the growth temperature (37 degr ...19751182151
characterization of mycoplasmatales virus-laidlawii 3.purified preparations of mycoplasmatales virus-laidlawii 3 were negatively stained and studied by electron microscopy. they were seen to consist of uniform sized particles having a polyhedral head, 57 nm by 61 nm, and a short tail, 25 nm long, joined to the head at one vertex by a collar. the particles were shown to have buoyant densities of 1-477 g/ml in csc1, 1-32 g/ml and 1-26 g/ml in potassium tartrate and a sedimentation coefficient, s20,w, of 290 +/- 13. they are composed of 35-2% double-s ...19751185149
lipid-sterol interactions in liposomes and membranes. 19751193252
transport properties of membrane vesicles from acholeplasma laidlawii. iii. evidence of active nature of glucose transport.membrane vesicles obtained from acholeplasma laidlawii accumulate glucose as well as maltose and fructose against their concentration gradient in the absence of exogenous energy sources. glucose uptake by membrane vesicles is inhibited by anaerobiosis and by electron transfer inhibitors, such as rotenone and amytal, but not by 2-heptyl-4-hydroxyquinoline n-oxide, antimycin a, cyanide and azide. rotenone, cyanide and amytal also produce a rapid efflux of glucose from the membrane vesicles. arsena ...19751193497
immunological properties of glycolipids from membranes of acholeplasma laidlawii.glycolipids, the predominant class of lipids in the membranes of acholeplasma laidlawii, are the haptenic determinants that react with anti-a. laidlawii serum to fix complement. the predominant complement-fixing activity of the membrane glycolipids was associated with the monoglucoysyl diglyceride, diglucosyl diglyceride, glycerlphosphoryl diglucosyl diglyceride (gpdd), and an unknown lipid b, which did not react with ninhydrin but release glucose and glycerol and traces of phosphorus upon hydro ...19751193716
mycoplasmas and cuffing pneumonia in a group of calves.the mycoplasmas found in the lungs of 20 calves, housed together for six months, and the related pulmonary pathology are reported. twelve calves had cuffing pneumonia and in this group there was a significantly higher isolation frequency of mycoplasma dispar and ureaplasma spp compared with the non-pneumonic group. mycoplasma bovirhinis and acholeplasma laidlawii were isolated from the lungs of calves in both groups. mycoplasma arginini was not recovered from the lungs of any calf. the significa ...19751198879
[respiratory activity of acholeplasma laidlawii cells and its role in the active transport of carbohydrates].the respiratory activity of the acholeplasma laidlawii cells was studied in order to elucidate a possible mechanism of coupling of transport with energy. the respiration of the cells is stimulated by ethanol, glucose, nadh, lactate, and pyruvate. the substrates of the krebs cycle have no effect on the respiration. the respiratory activity, stimulated by ethanol and glucose, is inhibited by the inhibitors of the respiratory chain, sh reagents, and the inhibitors of glycolysis. the results of expe ...19751207494
[radiosensitivity of mycoplasma and damage to their dna after irradiation (author's transl)]. 19751242851
serum lipoproteins as cholesterol donors to mycoplasma membranes. 19761252244
effectiveness of certain teat dips and sanitizers in vitro and on teat skin against mycoplasma agalactiae subsp. bovis.seven teat dip and sanitizer products were tested in vitro and in vivo for mycoplasmacidal activity against mycoplasma agalactiae subsp. bovis (m. bovimastitidis). most, but not all products tested appeared to kill the mycoplasma at satisfactory dilutions. these mycoplasma survived longer on teat skin during humid, rainy weather than during warm, dry weather. acholeplasma laidlawii was frequently found on normal teat skin.19761261269
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