Publications

effect of penicillin on the multiplication of meningopneumonitis organisms (chlamydia psittaci).	although formation of infectious particles of meningopneumonitis organism in l cells was completely inhibited by 1 or more units of penicillin per ml, multiplication of reticulate bodies was observed, by light microscopy, in the presence of 200 units of penicillin per ml in stained smears of infected cells. when reticulate bodies were purified from cultures containing penicillin after 18, 30, and 45 hr of incubation, continuously increasing yields were obtained. when penicillin was added to infe ...	1968	5686015
stability of the nucleic acids of l cells after infection with the meningopneumonitis agent.	the stability of host nucleic acids in l cells infected with chlamydia psittaci (strain meningopneumonitis) was studied. the l cells were prelabeled with either (32)p-orthophosphate, (3)h-uridine, or (3)h-thymidine. after infection, the redistribution of each label among the different fractions of host and parasite was quantitatively determined and compared. there were no signs of accelerated degradation of host nucleic acid as the consequence of meningopneumonitis infection. comparison of the s ...	1968	5724971
inhibition of thymidine kinase activity and deoxyribonucleic acid synthesis in l cells infected with the meningopneumonitis agent.	the activities of enzymes related to deoxyribonucleic acid (dna) synthesis were studied in uninfected l cells and in l cells infected with chlamydia psittaci (strain meningopneumonitis). the meningopneumonitis agent multiplied normally but failed to induce the synthesis of thymidine kinase in lm (tk(-)) cells which contain no thymidine kinase in the uninfected state. it was concluded that this microorganism has no thymidine kinase of its own and that it does not depend on the functioning of the ...	1968	5724972
effect of infection with the meningopneumonitis agent on deoxyribonucleic acid and protein synthesis by its l-cell host.	cycloheximide, which had already been shown to inhibit protein synthesis in earle's l cells (mouse fibroblasts) without having any effect on the multiplication or protein synthesis in chlamydia psittaci (strain meningopneumonitis) infecting these host cells, also caused greater than 90% inhibition of deoxyribonucleic acid (dna) synthesis in l cells after a 3-hr exposure to the drug. l cells infected with the meningopneumonitis agent and treated with cycloheximide were used to follow meningopneum ...	1969	5773017
role of exogenous adenosine triphosphate in catabolic and synthetic activities of chlamydia psittaci.	the synthetic activities of isolated cells of the meningopneumonitis strain (mn) of chlamydia psittaci were investigated and further observations were made on their catabolic reactions. these observations included the demonstration of co(2) production from aspartate in the presence of pyruvate and the formation of pyruvate from glucose-6-phosphate. both reactions were enhanced by added adenosine triphosphate (atp). of a large number of compounds tested, only glucose-6-phosphate, pyruvate, aspart ...	1969	5773026
plaque formation in chick embryo fibroblast cells by chlamydia isolated from avian and mammalian sources.	fifteen strains of chlamydial agents, 2 chlamydia trachomatis and 13 chlamydia psittaci, were tested for plaque formation on chick embryo fibroblast cells. c. trachomatis strains did not form plaques; 12 strains of c. psittaci did form plaques and 1 strain did not. the distribution of plaque sizes with c. psittaci strains was studied and it was found that the 12 strains could be tentatively grouped into three plaquing types: small (<0.50 mm), intermediate (0.50 to 0.90 mm), and large (>0.90 mm). ...	1969	5784206
serologic evidence of natural and experimental transfers of chlamydia psittaci between wild and domestic animals.		1969	5817785
the toxicity of meningopneumonitis organisms (chlamydia psittaci) at different stages of development.		1969	4900518
lipid synthesis by isolated chlamydia psittaci.	the isolated cells of the host-dependent meningopneumonitis agent, chlamydia psittaci, were shown to incorporate radioactive carbon from aspartate, isoleucine, and glucose-6-phosphate into cell lipids. the nature of this incorporation was investigated. radioactivity was found only in the fatty acids and primarily in the phosphatidyl ethanolamine, and, to a lesser extent, in the phosphatidyl choline fractions. branched-chain fatty acids, not found in host lipid, were shown to constitute a large p ...	1969	5354949
morphologic and cytochemic studies on the development of chlamydia psittaci in a tissue culture of a cold-blooded animal.		1969	4097119
respiration of l cells infected with chlamydia psittaci.		1970	4099299
effect of metabolic inhibitors on the production of chlamydia psittaci by infected l cells.		1970	4099301
electron microscopic observations on the effects of penicillin on the morphology of chlamydia psittaci.	l cells were infected at high multiplicity with meningopneumonitis organisms and incubated in medium containing 200 units per ml of penicillin. at intervals up to 48 hr after infection, cells were removed and thin sections were prepared for electron microscopic studies on the morphology of the developing organism. penicillin had no effect on the initial reorganization of the infecting elementary body to form the developmental reticulate body (rb), and, up to 12 hr after infection, the treated an ...	1970	5413965
antibody for chlamydia psittaci in ascitic fluids of immunized mice implanted with sarcoma 180.		1970	5423527
[study with electron microscopy of the development and morphology of chlamydia psittaci in mouse macrophages].		1970	5459084
cross immunity among strains of chlamydia psittaci.		1970	5486731
demonstration of host-species-specific antigens in chlamydia psittaci by the plaque-reduction test in l-cell tissue cultures. preliminary observations.		1970	4920044
lipid composition of chlamydia psittaci grown in monkey kidney cells in defined medium.	the lipid compositions of (i) monkey kidney (mk-2) cells cultivated in eagle's minimal essential medium (mem) with 5% calf serum, (ii) mk-2 cells cultivated in waymouth medium supplemented with 20 mug of sodium oleate and 2 mg of bovine albumin per ml, (iii) chlamydia psittaci strain 6bc grown in the latter host system, and (iv) calf serum were compared. strain 6bc contains 31% phosphatidyl ethanolamine (pe) and 15% phosphatidyl glycerol (pg), whereas the host cell contains almost the same amoun ...	1970	4987309
glucose requirements of l cells infected with chlamydia psittaci.		1970	4394906
cell wall synthesis by chlamydia psittaci growing in l cells.	biochemical events accompanying changes in structure and behavior of the cell walls of chlamydia psittaci strain 6bc during its developmental cycle in l cells (mouse fibroblasts) were studied by measuring at short intervals the effect of d-cycloserine and penicillin g on incorporation of labeled intermediates into acid-insoluble fractions of infected l cells in which host incorporation had been inhibited by cycloheximide and into intact chlamydial cells and cell walls separated from the infected ...	1970	16559091
glucose metabolism of l cells before and after infection with chlamydia psittaci.	glucose was not utilized at significantly different rates in suspensions of multiplying and nonmultiplying adult mouse fibroblasts (l cells). infection of l cells with chlamydia psittaci (strain meningopneumonitis) increased the rates of glucose utilization and lactate accumulation during the first 24 hr after infection without changing the rates of glucose utilization by the pentose or tricarboxylic acid cycles. it was concluded that the increased aerobic glycolysis represented a host response ...	1970	16559092
electron microscopic observations on the fine structure of cell walls of chlamydia psittaci.	l-cell cultures were infected with elementary bodies (eb) of meningopneumonitis organisms. cell walls were prepared from reticulate bodies (rb), which are the intracellular developmental forms into which eb are converted, and from eb at appropriate times after infection. when fragmented eb cell walls were shadowcast with platinum palladium alloy, about one-half of the fragments were seen to be composed of hexagonally arrayed structures on the inner side of the cell wall. when eb cell walls were ...	1970	16559112
lipid composition of the hemagglutinating active fraction obtained from chick embryos infected with chlamydia psittaci 6bc.	the lipid composition of the concentrated hemagglutininating active fraction (hf) of allantoic fluid from infected eggs, but free from chlamydia psittaci 6bc, was compared to concentrated normal allantoic fluid (naf). phosphatidyl-choline (pc) and phosphatidylethanolamine were the major lipid classes of the total phospholipid fraction. some quantitative differences were found in the amount of pc and phosphatidylserine present in hf and naf. lysophosphatidylcholine was present in hf but absent in ...	1970	16557838
inhibition of deoxyribonucleic acid synthesis in synchronized populations of l cells infected with chlamydia psittaci.	infection of l cells with chlamydia psittaci inhibited the burst of deoxyribonucleic acid synthesis that occurs when the host cells are released from a double thymidine block.	1971	16557980
derivation of a borg strain of chlamydia psittaci attenuated for mice.	the method of derivation and virulence of a new attenuated variant (abg) obtained during passage of the virulent borg strain in embryonated eggs in the presence of p-aminobenzoic acid are described.	1971	16558005
[ultrastructure and cytochemistry of chlamydia psittaci].		1971	4939597
control of contamination in psittacosis specimens by antibiotics.	diluent containing a combination of vancomycin, kanamycin, and streptomycin is shown to be more effective than diluent previously used for isolating chlamydia psittaci from bird tissue specimens.	1971	4940879
electron microscopic observations on the structure of the envelopes of mature elementary bodies and developmental reticulate forms of chlamydia psittaci.	purified suspensions of chlamydia psittaci were prepared from l cells. thin sections of intact elementary bodies and intact developmental reticulate bodies and of their purified envelopes were observed by electron microscopy. in both intact organisms and partially purified envelopes, two membranous structures, each appearing in electron micrographs as two darkly stained layers, were observed. in the elementary body sections, the outer membrane was round, apparently rigid, and was not soluble in ...	1971	5541020
morphologic and cytochemic studies on the development of chlamydia psittaci in tissue culture of a cold-blooded animal at 20 degrees c.		1971	4101542
lysosomes in l cells infected with chlamydia psittaci 6bc strain.		1971	4106184
[phase contrast microcinematographic analysis of the intracellular development of chlamydia psittaci].		1971	4109492
inapparent respiratory infection of inbred swiss mice with sulfadiazine-resistant, iodine-negative chlamydiae.	three chlamydial strains were isolated from the lungs of three different strains of mice that were inbred for over 30 years. these chlamydial strains were resistant to sulfadiazine and did not induce iodine-positive, glycogen-like material in the inclusions of infected l cells which characterizes them as chlamydia psittaci.	1971	4117289
properties of a chlamydia psittaci isolated from muskrats and snowshoe hares in canada.		1971	4328689
interaction of l cells and chlamydia psittaci: entry of the parasite and host responses to its development.	the entry and development of chlamydia psittaci in the l cell was studied by using purified, infectious parasites at high multiplicity. entry of the parasite was accomplished by an act of phagocytosis by the host which was independent of an adsorption stage but was temperature-dependent. kinetic studies of phagocytosis performed with (14)c-amino acid-labeled, purified parasites indicated that the rate of phagocytosis was directly proportional to the multiplicity of inoculation. electron microsco ...	1972	4336694
[influence of quartz, carbon, titanium oxide and asbestos dusts on the experimental disease in mice induced with chlamydia psittaci].		1972	4339891
location of polysaccharide on chlamydia psittaci by silver-methenamine staining and electron microscopy.	previous serological studies have indicated that the group antigen of chlamydial organisms is composed of an acidic polysaccharide and a lipid component. the present study was undertaken in an effort to locate this polysaccharide complex by use of electron microscopy and a silver-methenamine marker. the meningopneumonitis strain of chlamydia psittaci was propagated in hela-m cell culture. organisms were purified by differential centrifugation, treatment with genetron, and by gel filtration. afte ...	1972	4130428
growth of chlamydia psittaci strain meningopneumonitis in mouse l cells cultivated in a defined medium in spinner cultures.		1972	4567659
detection of chlamydial antibodies in animal sera by double diffusion in gel.	postinoculation sera collected from pigeons, turkeys, guinea pigs, sheep, a calf, a rabbit, and a horse experimentally infected with various strains of chlamydia psittaci yielded a high incidence of positive reactions when tested by double diffusion in gel. antigen was a deoxycholate extract of sa-2 strain of c. trachomatis. good correlation was obtained with results of complement fixation tests, whereas double diffusion in gel was less sensitive. immunoelectrophoresis of the antigen revealed pr ...	1972	4622980
indirect hemagglutination test for chlamydial antibodies.	an indirect hemagglutination (iha) test is described for chlamydial antibodies in psittacosis diagnostic sera; for this test tanned sheep erythrocytes sensitized with a deoxycholate extract of chlamydia psittaci grown in vero cell monolayers were used. adaptation of the iha test to the microtiter system decreased sensitivity; nevertheless, the microtiter-iha test was more sensitive than the complement fixation test. lymphogranuloma venereum antibodies also were detected by using antigen extracte ...	1972	4626906
detection of chlamydia psittaci by immunofluorescence.	a direct fluorescent-antibody (fa) test was developed to detect chlamydia psittaci in dural impressions from specimen-inoculated mice. technical procedures for the test were compared. c. psittaci was found in mice after infection as early by the fa technique as it was by cytochemical staining methods usually used. the lymphogranuloma venereum organism was also stained by conjugated antibody to c. psittaci. a distinctive advantage of the described fa test is that organisms are identified immunolo ...	1972	4626909
formation and destruction of internal membranes in l cells infected with chlamydia psittaci.	l cells (mouse fibroblasts), uninfected and infected with chlamydia psittaci (meningopneumonitis strain), were labeled with (14)c-amino acids, and their membranous organelles were separated by isopycnic equilibrium centrifugation of whole cell homogenates on discontinuous sucrose density gradients. incorporation of labeled amino acids into host and parasitic proteins was differentiated on the basis of susceptibility to cycloheximide. twenty hours after infection with c. psittaci, incorporation o ...	1973	4697788
miniature cell formation in chlamydia psittaci.	in an electron microscope study on the developmental cycle of the goat pneumonitis strain of chlamydia psittaci in l cells, it was observed that miniature reticulate bodies, measuring approximately 0.2 mum in diameter and surrounded by double unit membranes, were produced infrequently from normal-sized reticulate bodies through a "budding"-like process. as little as 0.1 mug of penicillin per ml greatly increased the frequency of the miniature reticulate body formation.	1973	4698212
[resistance of chlamydia psittaci against chlortetracycline].		1973	4699553
natural intestinal infection with chlamydia psittaci in a closed bovine herd: serologic changes, incidence of shedding, antibiotic treatment of the herd, and biologic characteristics of the chlamydiae.		1973	4703505
pathogenicity of a strain of chlamydia psittaci of bovine intestinal origin for neonatal calves.		1973	4703506
effect of chloramphenicol, rifampicin, and nalidixic acid on chlamydia psittaci growing in l cells.		1973	4734704
[electron microscopic studies on morphological changes of chlamydia psittaci induced by a small dose of penicillin (author's transl)].		1973	4808058
immunofluorescence of peritoneal phagocytes after infection in vivo with egg-attenuated chlamydia psittaci 6bc.		1973	4358601
electron microscope observations on the effects of polymixin b sulfate on cell walls of chlamydia psittaci.	the effects of polymixin b sulfate on cell walls of mature elementary body (eb) and of immature developmental reticulate body (rb) of chlamydia psittaci were investigated. when purified eb were treated with polymixin (10(4) units per ml or more) at 37 c for 60 min, about 70% of eb was found to be covered with a number of projections. further incubation did not increase the percentage affected. the infectivity after treatment as assayed by the inclusion counting technique was reduced by 70% of th ...	1973	4120068
ultrastructural studies of chlamydia psittaci 6bc variant strains. i. ultrastructure of the surface layers of egg-passaged 6bc strain.		1973	4127533
fine structures of cell envelopes of chlamydia organisms as revealed by freeze-etching and negative staining techniques.	the cell walls of chlamydia psittaci (meningopneumonitis strain) were examined by the freeze-etching and negative staining techniques. it was observed that the cleaved convex surface of the developmental, reticulate body was covered with numerous non-etchable particles 9 to 10 nm in diameter, these particles being rarely seen on the concave surface. similarly, the convex surface of the mature, elementary body (eb) was covered with many particles but the concavity lacked these particles. after et ...	1973	4127629
[the immune peroxidase method for demonstration of virus and chlamydia antigens. ii. demonstration of the evolutional circle of chlamydia psittaci in peritoneal macrophages of infected mice].		1974	4824502
cycloheximide-resistant glycosylation in l cells infected with chlamydia psittaci.	l cells (mouse fibroblasts), uninfected and infected with the meningopneumonitis strain of chlamydia psittaci, were labeled with [(14)c]glucosamine, and their membranous organelles were separated by isopycnic equilibrium centrifugation of whole cell homogenates on discontinuous sucrose gradients. glycosylation of host membranes continued throughout the infection. cycloheximide almost completely inhibited glycosylation in uninfected l cells, but it only partially inhibited the process in infected ...	1974	4856239
hemagglutinin in cell walls of chlamydia psittaci.	intact purified elementary bodies (eb) of chlamydia psittaci agglutinate chicken erythrocytes in low titer, whereas homogenates of eb and of eb cell walls agglutinate at much higher titers depending on the extent of disruption by shaking and sonication. the hemagglutinin is contained in the cell envelope and can be purified with cell wall fractions. treatment of cell wall with sodium dodecyl sulfate completely inactivated the hemagglutinin. purified hemagglutinin was found to have an identical p ...	1974	4856587
[chlortetracycline content in feces from psittacines used for chlamydia psittaci isolation].		1974	4856817
proteinase produced by chlamydia psittaci in l cells.	l cells (mouse fibroblasts) infected with chlamydia psittaci (strain meningopneumonitis) produced a proteinase differing in solubility in ammonium sulfate from the proteinase of uninfected l cells. synthesis of the enzyme was inhibited by chloramphenicol but not by cycloheximide, indicating that the new proteinase in infected l cells was synthesized by chlamydia psittaci. the chlamydial proteinase had no demonstrable ion requirements and was not inhibited by a variety of inhibitors of proteinase ...	1974	4857192
ocular involvement with chlamydia psittaci (strain m56) in rabbits inoculated intravenously.	fourteen albino rabbits were inoculated intravenously with 10(3.5)-10(4.0) mouse icld(50) of chlamydia psittaci (strain m56) of mammalian origin. ocular lesions accompanied the chlamydial infection in the rabbits. bilateral anterior uveitis, a common occurrence, began on the second or third day and subsided by the tenth day whereas keratoconjunctivitis was observed infrequently. after 15 days the most prominent microscopic lesion was iritis. accumulations of inflammatory cells, mainly plasma cel ...	1974	4277591
lysosomes and the "toxicity" of rickettsias. vi. in vivo response of mouse peritoneal phagocytes to l-cell-grown chlamydia psittaci 6bc strain.	the l-cell-grown 6bc strain of c. psittaci inoculated intraperitoneally in mice induced an injurious effect on mononuclear phagocytes and their lysosomes; the influx of polymorphonuclear phagocytes (pmn's) increased markedly and the pmn's showed karyorrhexis and lysis. cytochemical methods failed to detect chlamydial forms in peritoneal fluids from day 1 and up to 6 days after inoculation of mice. chlamydial infectivity was not detected in either the cell-bound or the cell-free fractions of peri ...	1975	1090349
competition between chlamydia psittaci and l cells for host isoleucine pools: a limiting factor in chlamydial multiplication.	l cells (mouse fibroblasts) supported the multiplication of the obligately intracellular parasitic bacterium chlamydia psittaci (strain 6bc) when incubated in fresh growth medium (medium 199 + 5% fetal calf serum). when incubated in the medium supernatant from a 24-h-old culture of uninfected l cells (24-h used medium), uninfected cells did not divide and infected cells did not provide an adequate environment for the multiplication of c. psittaci, which persisted in a noninfectious latent state ...	1975	1095493
immunofluorescence of peritoneal phagocytes after infection of mice with l-cell-attenuated chlamydia psittaci 6bc.	large amounts of particulate antigen of chlamydia psittaci 6bc attenuated by growth in l cells were phagocytized by peritoneal mononuclear phagocytes during the 1st h after intraperitoneal inoculation. the phagocytes subsequently destroyed the immunofluorescent (if) properties of the chlamydial antigens. it is suggested that the early damage of phagocytes by lysosomal enzymes activation induced by chlamydiae contributed to the relatively early disappearance of if antigens from the peritoneal flu ...	1975	1097065
an epornitic of fatal chlamydiosis (ornithosis) in south carolina turkeys.	an unusual epornitic of fatal chlamydiosis occurred in a flock of 10,283 domestic turkeys in south carolina. total mortality over a 2-week period was 483 birds (4.7% of the flock). the principal gross lesion was severe pericarditis, but there was little or no airsacculitis, an observation at variance with many previous reports of chlamydiosis. furthermore, an unusually heavy infestation of the turkeys with sanguivorous black flies (simulium slossonae and s congareenarum) was observed at the time ...	1975	1112744
protein profiles of dense-centered forms of five chlamydial strains of animal origin.	purified dense-centered form of 1 bovine strain (lw613) and 3 ovine strains (b577, 034-eye, and 047-eye) of chlamydia psittaci and 1 murine strain of chlamydia trachomatis (mopn) were dissociated in the presence of sodium dodecyl sulfate (sds) and 2-mercaptoethanol. the number of polypeptides detected in the 5 strains varied between 17 and 20, with a molecular weight range of 29,000 to 120,000. two polypeptides predominated and comprised approximately a third of the total protein in each of the ...	1975	1147351
electron microscopy of the in vivo internalization of virulent chlamydia psittaci 6bc strain.	the internalization of virulent chlamydia psittaci 6bc particles by wandering mononuclear phagocytes in the peritoneal cavity of intraperitoneally inoculated mice occurred asynchronously, i.e., fragile reticulate bodies (rb) appeared to be more readily phagocytized than the rigid elementary bodies (eb). early damage of mononuclear phagocytes occurred after internalization of chlamydiae. this was followed by a decreased uptake of particles, and may explain the relatively long persistence (up to ...	1975	1148946
utilization of l-cell nucleoside triphosphates by chlamydia psittaci for ribonucleic acid synthesis.	long-term, 32-p-labeled l cells were infected with the obligately intracellular parasite chlamydia psittaci (strain 6 bc). at 20 h postinfection, [3-h]uridine was added, and the infected cells were sampled at intervals for incorporation of the labels into the uridine triphosphate (utp) and cytidine triphosphate (ctp) pools of the host l cell and the uridine monophosphate (ump) and cytidine monophosphate (cmp) in 16s ribosomal ribonucleic acid (rna) of the parasite. the specific activity of the n ...	1975	1168632
ultrastructural cytochemical evidence for the activation of lysosomes in the cytocidal effect of chlamydia psittaci.	the cytopathic effect of the polyarthritis strain of chlamydia psittaci was studied in cultured bovine fetal spleen cells and found to be mediated by the release of lysosomal enzymes into the host cytoplasm during the late stages of chlamydial development. ultrastructural cytochemical analysis and cell fractionation studies of infected cells revealed a close relationship between the stage of chlamydial development, fine structural features of the host, and localization of lysosomal enzyme activi ...	1975	1172486
insidious endocarditis caused by chlamydia psittaci.		1975	1212580
[experimental infection of guinea pigs with chlamydia. 1. pathomorphological studies].	the changes that occurred following nasal instillation of a bovine strain of chlamydia psittaci were characterized by hypertrophy and proliferation of epithelial cells and exudates containing polymorphonuclear leukocytes, with acute bronchopneumonia and less intense inflammatory reactions in nasal and tracheal mucosa, spleen and pulmonary lymph nodes. the intestines, liver, kidney and brain were scarcely affected. there was little prospect of complete recovery from the clinically mild, or even s ...	1975	1227428
[morphological ultrastructural and immunological studies of a rickettsia isolated from a parrot (author's transl)].	a rickettsia isolated from a parrot was found by use of electron microscopic and serological technic to be a coxiella burneti. in cell culture one can see a dramatic polymorphism and a gram negative-like structure of the cell wall. they divide by binary fission with no appearance of a complexe cycle of development like the one described for chlamydia psittaci. many myelinic fibrils and altered coxiella suggest that the host cell react very deaply.	1975	1238044
ultrastructural studies of chlamydia psittaci 6bc in situ in yolk sac explants and l cells: a comparison with gram-negative bacteria.	chlamydia psittaci (6bc) was grown in yolk sac explants and in l cells and fixed by perfusion in situ to provide undamaged material for comparison with gram-negative bacteria. reticulate, intermediate, and elementary bodies were all seen to lack a well-defined periplasmic space; intermediate and elementary bodies showed condensations of the nucleoid which differ from common bacterial configurations; and the cytoplasm of highly condensed elementary bodies was much more electron dense than that of ...	1975	1238156
the effect of purification on the ultrastructure and infectivity of egg-attenuated chlamydia psittaci (6bc).	a procedure is described for the purification of mixed populations of the three different morphological forms of chlamydia psittaci (6bc) from infected yolk sac membranes. elementary bodies and small intermediate bodies are not perceptibly damaged during purification which involves homogenization of the host cells, differential centrifugation, sedimentation through 20% sucrose, and treatment with trypsin. the observation that elementary bodies undergo plasmolysis in 20% sucrose is interpreted as ...	1975	1238157
effect of alkali on the structure of cell envelopes of chlamydia psittaci elementary bodies.	suspensions of isolated cell envelopes of infectious elementary bodies (eb) of chlamydia psittaci at alkaline ph showed a rapid, extensive decrease in absorbance, accompanied by the release of a cell envelope component in a sedimentable form. this phenomenon was observed both at 0 c and with envelopes which had been previously heated to 100 c. monovalent and divalent cations effectively inhibited the turbidity loss, whereas ethylenediaminetetraacetate (edta) caused an accelerated decrease in tur ...	1976	1375
protein-carbohydrate-lipid complex isolated from the cell envelopes of chlamydia psittaci in alkaline buffer and ethylenediaminetetraacetate.	exposure of isolated cell envelopes from purified infectious elementary (eb) of chlamydia psittaci to sodium carbonate-bicarbonate buffer at ph 10 plus ethylenediaminetetraacetate (edta) results in partial solubilization of the total protein. the released materials represent 20% of the dry weight, 16% of the total protein, 40% of the total carbohydrate, and 9% of the total lipid of the cell envelopes. sucrose density gradient centrifugation, and sephadex g-200, sepharose 4b, or diethylaminoethyl ...	1976	1376
ultrastructural studies of the nucleoids of the pleomorphic forms of chlamydia psittaci 6bc: a comparison with bacteria.	the nucleoids of the various pleomorphic forms of chlamydia psittaci have been examined by direct observation of infected cells and by observations on isolated particles. the fixation and staining methods used were the same as those routinely used for the examination of bacteria to facilitate the comparison of chlamydial fine structure with that of bacteria. the nucleoids of reticulate bodies were composed of fine fibrils which extended throughout these particles. the nucleoids of intermediate b ...	1976	56212
[aetiological studies on viral pneumonia (author's transl)].	401 cases of viral pneumonia diagnosed between january 1973 and august 1975 were investigated serologically by the complement-fixation test. the percentage distribution of the responsible pathogenic organism in this series of cases was as follows: influenza virus a 45.9%, mycoplasma pneumoniae 19.5%, coxsackie b viruses 9.2%, cytomegalovirus 7.5% and chlamydia psittaci 8.5%. the remaining 9.4% cases were caused by adeno, parainfluenza, measles, influenza b, herpes simplex and respiratory syncyti ...	1976	185813
[atypical pneumonia, etiology and possibilities for the diagnosis (author's transl)].	beginning with the antimicrobial chemotherapy a decrease in the incidence of bacterial pneumonias is accompanied by a relative increase in the incidence of the so-called atypical pneumonia. this disease syndrome is predominantly caused by mycoplasma pneumoniae, chlamydia psittaci, coxiella burneti and various viruses. in addition, bacteria which are usually involved in lobar pneumonia may occasionally cause atypical pneumonias. the present publication is concerned with the most frequently occurr ...	1976	186398
experimental chlamydiosis in wild and domestic lagomorphs.	chlamydia psittaci (strain m56, the agent of epizootic chlamydiosis of muskrats and hares) was highly lethal for the snowshoe hare (lepus americans) following intravenous inoculation, whereas the agent was much less virulent for cottontail (sylvilagus floridanus) and albino domestic rabbits (oryctolagus cuniculus). tissue titres of strain m56 were generally higher after 96 hr in the snowshoe hare than in tissues of the other lagomorphs. spleen, liver and bone marrow were apparently the chief sit ...	1976	933312
utilization of exogenous thymidine by chlamydia psittaci growing in the thymidine kinase-containing and thymidine kinase-deficient l cells.	the incorporation of [3h]thymidine into the deoxyribonucleic acid (dna) of chlamydia psittaci (strain 6bc) growing in thymidine kinase (adenosine 5'-triphosphate-thymidine 5'-phosphotransferase, ec 1.7.1.21)-containing l cells, l(tk+), and thymidine kinase-deficient l cells, lm(tk-), was examined by autoradiography. label was detected over c. psittaci inclusions in l(tk+) but not lm(tk-) cells. no evidence for a chlamydia-specific thymidine kinase activity in either l(tk+) or lm(tk-) cells was o ...	1976	942715
autoradiography of [3h]thymidine-labeled chlamydia psittaci 6bc in mononuclear phagocytes.	incorporation of tritiated [3h]thymidine by chlamydia psittaci 6bc was achieved by growing the parasites in chick embryo yolk sac explants which were exposed to exogenous labeled thymidine. these labeled, purified chlamydiae were next observed by autoradiography within mouse peritoneal macrophages. the number of silver grains remained constant in the cytoplasm of macrophages throughout the developmental cycle of the parasite. the proliferation of labeled chlamydiae in macrophages was confirmed b ...	1976	943214
alterations in the ultrastructure of chlamydia psittaci 6bc harvested from the allantoic fluid of chick embryos.	the allantoic fluid of chick embryos infected with chlamydia psittaci is routinely used as a source of material for the study of the chemical and biological properties of the chlamydiae. we have examined pellets recovered from this allantoic fluid by low- and high-speed centrifugation, as well as high-speed pellets which had been stored at -70 degrees c, and we find that all of the pleomorphic forms of the chlamydiae are present in these materials. the reticulate bodies and large intermediate bo ...	1976	943217
characterization of miniature pig kidney cells and their resistance to chlamydial infection.	a miniature pig kidney cell line has been established from porcine fetuses taken aseptically by hysterectomy and maintained for more than 50 passages in eagle's minimal essential medium containing 10% heat-inactivated newborn calf serum. cell transfers were performed each week. primary and serially passaged cells were found to be highly refractory to infection by chlamydia trachomatis strains tw-3, bour, and lgv 440l and chlamydia psittaci strains meningopneumonitis and 6bc and insusceptible to ...	1976	944002
detection of dna polymerase activity in chlamydia psittaci.	dna polymerase activities of intact and disrupted suspensions of the mature infectious, extracellular elementary bodies of the meningopneumonitis strain of chlamydia psittaci were studied. intact elementary bodies failed to incorporate labeled thymidine triphosphate (ttp), but homogenates of the organisms did incorporate ttp into the acid insoluble fraction; the reaction continued at a linear rate for 60 min and the newly synthesized dna hybridized exclusively with dna derived from c. psittaci e ...	1976	957524
differences in physicochemical and antigenic properties of chlamydial strains.	antigenic analysis of chlamydia psittaci, c. trachomatis, and lymphogranuloma venereum (lgv) revealed basic physicochemical differences among the three chlamydial strains. these were manifested in structural, isoelectric points, absorption spectra, and in the characteristics of the chromophobe-containing proteins. the effective period of sonication for c. psittaci and c. trachomatis is around 60 min during which the linkages most susceptible to external sonication forces were broken, releasing a ...	1976	963615
requirements for ingestion of chlamydia psittaci by mouse fibroblasts (l cells).	ingestion of 14c-amino acid-labeled chlamydia psittaci (6bc) by mouse fibroblasts (l cells) was inhibited when the host cells were incubated for 30 min at 37 degrees c in earle salts containing 10 mug of crystalline trypsin per ml. tryptic digestion also inhibited the ingestion of 1-mum polystrene latex beads. trypsin-treated l cells almost completely recovered their ability to ingest chlamydiae after 4 h at 37 degrees c in medium 199 with 5% fetal calf serum. cycloheximide (10 mug/ml) blocked t ...	1976	965090
immediate toxicity of high multiplicities of chlamydia psittaci for mouse fibroblasts (l cells).	one hour after suspensions of mouse fibroblasts (l cells) were exposed to 500 to 1,000 l-cell 50% infectious doses of chlamydia psittaci (6bc), the l cells failed to attach to and spread out on solid substrates, phagocytosed polystyrene latex spheres at reduced rates, incorporated less [14c]isoleucine into protein, and had smaller soluble pools of nucleoside triphosphates. the infected l cells began to die at 8 h and were all dead by 20 h. lower multiplicities of infection took correspondingly l ...	1976	985806
phagocytic and chlamydiae-inhibiting activities of stimulated and nonstimulated periotneal mouse macrophages.	phagocytic and chamydiacidal properties of nonstimulated and stimulated mouse mononuclear cells for two chlamydia psittaci 6bc strains were investigated. it was determined that macrophages kept in monolayer culture (i.e. stimulated phagocytes) developed much more efficient chlamydiacidal ability than did cells kept in suspension directly after harvest (i.e. nonstimulated phagocytes). a thousandfold decrease of chlamydial infectivity was observed 60 min after induction of phagocytosis in stimulat ...	1976	986871
observations on the involvement of wildlife in an epornitic of chlamydiosis in domestic turkeys.	in an investigation of potential wildlife reservoirs of chlamydia psittaci at the site of an acute, highly fatal epornitic of chlamydiosis in domestic turkeys in texas, various species of wild birds and rodents were captured and tested for chlamydial serum antibodies and chlamydiae in their tissues. thirteen (65%) of 20 blackbirds (agelaius sp), 4 (44%) of 9 killdeer (oxyechus vociferus), 3 (27%) of 11 sparrows (passer sp) and 1 of 4 mourning doves (zenaidura macroura) were seropositive, but chl ...	1976	988009
some physical properties of a sheep pneumonia strain of chlamydia psittaci.		1976	997192
the incidence and aetiology of respiratory tract infections in general practice--with emphasis on mycoplasma pneumoniae.	the incidence of respiratory tract infections in patients seeking medical advice at a community care centre (dalby) during 1973 and 1974 was studied. about every third patient seen at this primary health station presented with signs of such infections. in the age groups less than 10, 10-19, 20-39, 40-59 and greater than or equal to 60 years, respiratory tract infections accounted for 65, 45, 32, 18 and 9% of the fotal number of diagnoses made during 1974. the aetiology of acute respiratory tract ...	1976	783048
observations of the surface projections of infectious small cell of chlamydia psittaci in thin sections.		1976	799722
vaccination against feline pneumonitis.	a commercially available modified live chlamydial vaccine against feline pneumonitis was tested in 26 cats for its ability to protect against aerosol challenge exposure to the feline pneumonitis strain of chlamydia psittaci. after cats were challenge exposed (30 days after vaccination), pyrexia of greater than 40.0 c occurred in 81% of nonvaccinated (control) cats and in 13% of vaccinated cats (principals). evidence of upper respiratory tract disease and the presence of the agent in ocular fluid ...	1977	921030
toxicity of low and moderate multiplicities of chlamydia psittaci for mouse fibroblasts (l cells).	when mouse fibroblasts (l cells) were infected in suspension or in monolayer with 10 to 100 50% infectious doses (id(50)) of chlamydia psittaci (6bc) per host cell, they showed signs of damage 24 to 48 h later. host-cell injuries were termed multiplication dependent when both the ingestion and subsequent reproduction of c. psittaci were required; when only ingestion but not replication was needed, the injuries were considered to be multiplication independent. the time that the injury was first a ...	1977	924681
enzyme-linked immunosorbent assay for chlamydial antibodies.	an enzyme-linked immunosorbent assay (elisa) detected chlamydial antibodies in human sera. the assay antigen produced in cell cultures infected with chlamydia psittaci was formalin-fixed to microplates. single convalescent-phase sera positive for chlamydial antibodies by a complement-fixation test were positive at even higher dilutions by elisa. paired sera with diagnostic rises in complement-fixing antibody showed seroconversion by elisa also. control sera from persons with no history of chlamy ...	1977	72759
modification of the microimmunofluorescence test to provide a routine serodiagnostic test for chlamydial infection.	a modification of the microimmunofluorescence test to provide a practicable routine serodiagnostic test for detecting and characterising chlamydial infection is described which uses four antigen pools, one of which corresponds with each of the four main clinical and epidemiological types of chlamydial infection. the three subgroup a chlamydia (chlamydia trachomatis) pools are: pool 1, hyperendemic trachoma tric agent serotypes a, b, and c; pool 2, paratrachoma tric agent serotypes d, e, f, g, h, ...	1977	326816
[plaque assay for chlamydia psittaci in tissue samples (author's transl)].	direct isolation of chlamydia psittaci (var, ovis) from mouse spleen was performed in parallel by plaque assay on mccoy cells and by staining of cytoplasmic inclusions in hela 229 cells. there was a significant difference between the frequency of isolation: the plaque technique was highly sensitive and reproducible; it offers a potential tool for investigations requiring the accurate quantitation of chlamydiae in tissue sample.	1977	334017
[chlamydia psittaci infections among hospital personnel].		1977	607278
sucrose density differences of chlamydia psittaci 6bc in relation to its host.	previous studies on chlamydia psittaci 6bc propagated in different hosts have shown differences in cytotoxicity but no differences in the ultrastructure of the individual particles. it is shown here that the 6bc strain derived from yolk sac of infected chick embryo sedimented in sucrose gradients at lower densities than the 6bc strain derived from l-cells. host-related modifications of lipid concentrations of the 6bc strains have been previously documented by others. it is thought that the pheno ...	1977	559537
growth of chlamydia psittaci in macrophages.	survival and growth of l-cell-cultivated chlamydia psittaci occurred in mouse macrophages in vitro. two major factors governing the intracellular fate of chlamydiae in macrophages are: (i) the multiplicity of infection (moi), i.e., the elementary body (eb)-to-macrophage ratio, and (ii) the state of the eb. at a low moi (1:1) survival and growth of live, untreated chlamydiae were optimal. the chlamydiae were internalized in macrophages within 30 to 40 min. eb proceeded to differentiate into retic ...	1978	565338
interaction of chlamydia psittaci with mouse peritoneal macrophages.	l-cell-grown chlamydia psittaci elementary bodies (eb) were rapidly phagocytized by mouse peritoneal macrophages in vitro. however, the intracellular fate of chlamydiae in macrophages appeared to be dependent on the multiplicity of infection (moi), i.e., the eb-to-macrophage ratio, and the treatment of the eb. at an moi of 1:1 or less, survival is maximal, and growth and multiplication of live, untreated chlamydiae did occur. in contrast, at a high moi (100:1), survival of chlamydiae is reduced, ...	1978	565339
division of single host cells after infection with chlamydiae.	mouse fibroblasts (l cells) were infected in suspension with chlamydia psittaci (6bc) and then plated out on a solid substrate at a density of 80 cells per cm2 so that the effect of chlamydial infection on the division of single host cells and their progeny could be determined. uninfected l cells multiplied with a mean generation time of 15 h. the generation time of single l cells infected with 1.5 50% infectious units (id50) of c. psittaci was over twice as long. half of the infected l cells ha ...	1978	624590
chlamydia psittaci infection of horses with respiratory disease.	two strains of chlamydia psittaci were isolated from the nasal tract of horses with acute respiratory disease. these 2 isolates (ns 121 and ns 172) were characterized as chlamydia on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacterial media and their possession of chlamydial common complement fixing group antigen. they were identified as c. psittaci on the basis of resistance to sodium sulphadiazine. the present strains were not pathogeni ...	1978	631105