| [dissociation of bcg strain by the action of heat. immunizing activity of variants obtained by dissociation]. | | 1964 | 5830291 |
| chromosome abnormality in rat leukemia induced by 7,12-dimethylbenz[a]anthracene. | a high percentage of consistent chromosome abnormality, trisomy of the longest telocentric chromosome, was found in leukemias induced in rats of the long-evans strain by pulse doses of 7,12-dimethylbenz[a]anthracene. cells with this abnormality were large, immature, and mononuclear and tended toward erythroblastic maturation. | 1967 | 6058345 |
| isolation of different mycelial fractions from submerged culture of streptomyces griseus strain by density gradient centrifugation. | | 1967 | 6072918 |
| ilvb-encoded acetolactate synthase is resistant to the herbicide sulfometuron methyl. | the herbicide sulfometuron methyl is a potent inhibitor of the branched-chain amino acid biosynthetic enzyme acetolactate synthase (als) isolated from bacteria, fungi, and plants. however, it did not prevent growth of wild-type salmonella typhimurium lt2 or escherichia coli k-12. these species each contain two acetolactate synthase isozymes. growth of s. typhimurium and e. coli mutants lacking als i was prevented by the herbicide, suggesting that activity of the remaining als isoenzyme (ii or ii ... | 1984 | 6090425 |
| [structural-functional organization of the sv40 virus chromosome. ii. characteristics of viral genome containing deletion in the regulatory region]. | structure of sv40 wild type virus genome differing from the well known 776 strain has been characterized. this particular strain (sv40) was used previously for viral chromatin analysis. we show here that sv40 strain differs from 776 strain by deletion in the beginning of the "late" region (enhancer). restriction nucleases mapping and nucleotide sequencing through this region reveal the absence of one full-length copy of 72 bp repeat. | 1984 | 6095024 |
| shope fibroma virus. iii: stimulation of the growth of the noncytocidal strain by a tumor promoter. | | 1983 | 6100467 |
| quantitative relationship between structure and mutagenic activity in a series of 5-nitroimidazoles. | the mutagenic activity of 20 5-nitroimidazoles was tested in salmonella typhimurium ta-100 strain by means of the ames test. a multiple regression analysis using the interaction term mr2 x hb and the chromatographic rm values yielded the equation: (formula see text); where c is the molar concentration (1 m x 10(-6) of each drug increasing the revertants by five times in the ames test. the interaction term mr2 x hb takes into account the positive effect exerted by substituents characterized by hi ... | 1983 | 6139889 |
| [biochemical criteria of mammalian cell sensitivity to glucocorticoids]. | the resistance of morris hepatoma cells strain 8994 to glucocorticoids which lack hormonal induction of tyrosine aminotransferase synthesis was studied. the cells of morris hepatoma 7777 were used as a sensitive strain by a criterion of the enzyme synthesis. using two-dimensional polyacrylamide gel electrophoresis, it was demonstrated that, i) in the cells of the "resistant" morris hepatoma strain 8994 glucocorticoids change the rate of synthesis of at least five proteins, ii) two of these prote ... | 1983 | 6140959 |
| antigenic heterogeneity associated with pilus aggregation and autoagglutinability in neisseria gonorrhoeae. | a type-specific antigen of neisseria gonorrhoeae was previously demonstrated by two-dimensional immunoelectrophoresis, and was produced by strains adapted to growth in subcutaneous chambers in guinea pigs. this antigen was also present in 'smooth' (non-autoagglutinating) variants selected directly from the first agar cultures of three clinical isolates, without chamber passage. the type-specificity of this antigen paralleled the reactions of pili in immune electron microscopy, suggesting that th ... | 1980 | 6166729 |
| [alteration in content of lipids and lipoproteins in blood of rabbits with experimental allergic polyneuritis and encephalomyelitis]. | experimental allergic encephalomyelitis an polyneuritis were caused in male rats of 2.5-3.0 kg body mass of the shinshilla strain by means of administration into the foot of the animals pads of homogenous basic protein myelin from bovine spinal cord and myelin from bovine sciatic nerve as a mixture containing complete freund's adjuvant. in the impaired rabbits total fraction of beta- and pre-beta-lipoproteins as well as content of cholesterol and triglycerides were increased in blood. antibodies ... | 1981 | 6169201 |
| immunological characterization of a low oncogenic mouse mammary tumor virus balb/cniv mice. | antigenic determinants of mouse mammary tumor virus (mumtv) from the low-mammary-tumor-incidence strain balb/cniv were compared by competition radioimmunoassay with those of mumtv's isolated from several high- and low-mammary-tumor-incidence mouse strains, using rabbit hyperimmune sera against balb/cniv mumtv and against mumtv from the high-mammary-tumor-incidence strain balb/cfc3h. using anti-balb/cfc3h serum in competition radioimmunoassay, balb/cniv mumtv lacked antigenic determinants present ... | 1981 | 6169849 |
| characterization of a purified glycoprotein from schistosoma mansoni eggs: specificity, stability, and the involvement of carbohydrate and peptide moieties in its serologic activity. | a major egg glycoprotein (meg) was purified from a crude soluble extract of schistosoma mansoni ova (egyptian strain) by successive steps of lectin affinity and ion-exchange chromatography. radioiodinated meg exhibited a single precipitation band upon immunodiffusion against antiserum from chronically infected mice, and ran as a single band on page (rf 0.38) and sds-page (rf 0.36). its estimated m.w. was 70,000. the degree of stage and species specificity of meg and the effect of various treatme ... | 1982 | 6174618 |
| altered salivary amylase gene in the mouse strain bxd-16. | an electrophoretic salivary amylase variant in the recombinant inbred mouse strain bxd-16 segregated in crosses as an allele at the salivary amylase locus. no other strain was found with the same combination of electrophoretic types of salivary and pancreatic amylase, and no sign of contamination by foreign genes from other strains was found. the variant therefore seems to have arisen during the inbreeding of the strain by a genetic alteration in the amylase complex. purified variant amylase had ... | 1982 | 6176569 |
| purification and properties of glucosyltransferase responsible for water-insoluble glucan synthesis from streptococcus mutans. | a glucosyltransferase responsible for water-insoluble glucan synthesis was purified from the culture fluids of streptococcus mutans 6715-15 strain by column chromatography on toyopearl hw-60 and subsequently on hydroxyapatite. the enzyme preparation gave a single band on analysis by polyacrylamide gel electrophoresis. the ph dependency of the activity showed two optimal peaks at 5.8 and 7.3 and the km values for sucrose were 1.4 and 3.3 mm at the respective optimal phs. the molecular weight dete ... | 1982 | 6179873 |
| effect of purine derivatives, papaverine hydrochloride, and imidazole on enterotoxin formation by clostridium perfringens type a. | the percentage sporulation and enterotoxin specific activity were improved for all of five clostridium perfringens strains, and numbers of heat-resistant spores were improved for four of five strains by replacing proteose peptone with peptone in duncan-strong (ds) medium. when raffinose replaced starch in ds, peptone was superior to proteose peptone in increasing percentage sporulation, numbers of heat-resistant spores, and enterotoxin formation for four of five strains. enterotoxin levels for a ... | 1982 | 6184146 |
| enhanced cellulolytic enzyme biosynthesis of fusarium sp. strain by mutation and optimization of culture conditions. | mutation and most favorable culture conditions resulted in 1.8 to 3.3-fold increase in beta-1, 4-endoglucanase and filter paper activity by fusarium sp. 25/2. culture fluid obtained after 3 days of growth of fusarium sp. mutant on modified saunders medium supplemented with 1% filter paper and 0.1% malt seedlings showed beta-1, 4-endoglucanase activity of 42.6 u/ml and fpa of 2.4 mg/0.5 ml x h. | 1983 | 6196946 |
| purification and properties of a cell-bound bacteriocin from a bacteroides fragilis strain. | a cell-bound bacteriocin was extracted from a bacteroides fragilis bf-11 strain by treating the cells with a low-molarity buffer (0.01 m tris-hydrochloride, ph 8.0). sucrose osmotic shock experiments and ultrasonic lysis of whole cells indicated that the majority of the bacteriocin was located at the cell surface. culture supernatants contained no significant bacteriocin activity. the bacteriocin was purified by deae-cellulose and sephacryl s200 chromatography and had an apparent molecular weigh ... | 1984 | 6201135 |
| high-sensitivity detection of newly induced lamb protein on the escherichia coli cell surface. | the kinetics of the appearance at the cell surface of the outer membrane lamb protein after induction were determined by using specific antibodies and radioiodinated protein a as a probe. this was done in two different induction systems. first, lamb protein was induced in a wild-type strain by the simultaneous addition of cyclic amp and maltose. second, an operon fusion strain in which the lamb gene is expressed under lac promoter control was used; in this system, lamb protein can be induced by ... | 1984 | 6204968 |
| complete amino acid sequence of heavy chain variable regions derived from two monoclonal anti-p-azophenylarsonate antibodies of balb/c mice expressing the major cross-reactive idiotype of the a/j strain. | the primary structure of a/j anti-p-azophenylarsonate (anti-ars) antibodies expressing the major a-strain cross-reactive idiotype (cria) has provided important insights into issues of antibody diversity and the molecular basis of idiotypy in this important model system. until recently, this idiotype was thought to be rarely, if ever, expressed in balb/c mice. indeed, it has been reported that balb/c mice lack the heavy chain variable segment (vh) gene that is utilized by the entire family of ant ... | 1984 | 6207261 |
| allosuppressor and allohelper t cells in acute and chronic graft-vs.-host disease. ii. f1 recipients carrying mutations at h-2k and/or i-a. | by induction of a graft-vs.-host reaction (gvhr) in nonirradiated h-2-different f1 mice, one can induce stimulatory pathological symptoms, such as lymphadenopathy and hypergammaglobulinemia, combined with the production of autoantibodies characteristic of systemic lupus erythematosus (sle). alternatively, the gvhr can lead to the suppressive pathological symptoms, such as pancytopenia and hypogammaglobulinemia, characteristic of acute gvh disease (gvhd). whether stimulatory or suppressive sympto ... | 1983 | 6218218 |
| induction of prophage lambda in escherichia coli reca- strain by n-methyl-n'-nitro-n-nitrosoguanidine. | induction of prophage by n-methyl-n'-nitro-n-nitrosoguanidine (mnng) occurred in a reca- strain lysogenic for lambda phage at a level significantly higher than the spontaneous level although the frequency was much lower than that of induction in a reca+(lambda) strain. the plaque-forming ability of lambda c17 super-infecting the reca-(lambda) strain pretreated with mnng increased with dose of mnng as it did for super-infection of the reca+(lambda) strain, indicating that the frequency of maturat ... | 1983 | 6219287 |
| regulated expression of the prolactin gene in rat pituitary tumor cells. | prolactin (prl) gene expression in three strains of gh cells (rat pituitary tumor cells) has been quantitated by measurement of: (a) intracellular and extracellular prl, (b) cytoplasmic translatable prl-specific mrna (mrnaprl), and (c) molecular hybridization of cytoplasmic poly(a) rna to cdnaprl (dna complementary to mrnaprl). three gh cell lines utilized in this investigation were a prl-producing (prl+) strain, gh4c1, a prl nonproducing 5-bromo-deoxyuridine resistnat (prl- brdurdr) strain, f1b ... | 1980 | 6252216 |
| factors affecting the expression of carcinoembryonic antigen at the surface of cultured human colon carcinoma cells. | factors affecting the expression of carcinoembryonic antigen (cea) at the surface of in vitro human colon carcinoma cells were determined using 125i-labeled antibodies. binding of specific anti-cea antibodies resulted in polar redistribution of cea, followed by endocytosis of most of the cea-anti-cea complexes. these processes were temperature and energy dependent. cea removed from the tumor cell surface by antibody was totally replaced within 6 hr at 37 degrees, and the reexpression of cea requ ... | 1980 | 6254650 |
| differential induction of squamous cell carcinomas and adenocarcinomas in mouse lung by intratracheal instillation of benzo(a)pyrene and charcoal powder. | differential induction of squamous cell carcinomas, adenomas, and adenocarcinomas was observed in the lungs of male c57bl/6 and c3h/he mice after repeated intratracheal instillation of benzo(a)pyrene (bp) and charcoal powder suspended in 0.9% nacl solution. when a high dose of bp (1.0 mg bp and 0.5 mg charcoal powder) was instilled intratracheally once a week for 8 weeks or when a low dose of bp (0.5 mg bp and 0.5 mg charcoal powder) was instilled once a week for 16 weeks, squamous cell carcinom ... | 1980 | 6258778 |
| multiple genetic changes can occur in the oral poliovaccines upon replication in humans. | poliovirus isolates of serotypes 2 and 3 from patients whose paralytic poliomyelitis cases were classified as oral vaccine-associated were analysed by oligonucleotide mapping of the virus genomes and by polyacrylamide gel electrophoresis of the virus proteins. oligonucleotide maps of all isolates were similar to the maps of the corresponding oral vaccine strain. no two isolates gave identical maps. most maps differed from that of the vaccine strain by at least one oligonucleotide spot. maps of s ... | 1981 | 6273502 |
| antigenic analysis of polioviruses isolated from a child with agammaglobulinemia and paralytic poliomyelitis after sabin vaccine administration. | a 3-year-old boy with agammaglobulinemia developed paralytic poliomyelitis on day 553 after being fed poliovaccine. non-vaccine-like type 2 polioviruses were isolated from 22 stools obtained within 684 days after the onset of illness. antigenic variations were observed among these viruses. the non-vaccine-like virus isolated 1 week after the onset of paralysis differed in virulence from the sabin type 2 vaccine strain in the neurovirulence test in monkeys, and did not have the same antigenic cha ... | 1981 | 6273701 |
| replication terminus of the bacillus subtilis chromosome. | bidirectional replication of the bacillus subtilis chromosome terminates at a point on the circular chromosome which is symmetrically opposite to the replication origin. since replication rates are similar in both "halves" of the chromosome, termination presumably occurs at the meeting point of the two replication forks. to investigate whether the dna sequence of this region of the chromosome contributes to the termination event, we have determined the latest replicating region of a chromosome i ... | 1982 | 6282803 |
| isolation of bromovinyldeoxyuridine-resistant strains of herpes simplex virus and successful chemotherapy of mice infected with one such strain by using acyclovir. | several strains of herpes simplex virus which were resistant to bromovinyldeoxyuridine were isolated by passaging the virus in the presence of the drug in tissue culture. the resistance of the majority of isolates was accounted for by their reduced ability to induce the enzyme thymidine kinase. these strains were co-resistant to acyclovir, but showed reduced pathogenicity in mice. however, another type of bromovinyldeoxyuridine-resistant virus was isolated which induced normal levels of thymidin ... | 1982 | 6295272 |
| binding of fibronectin to the surface of group a, c, and g streptococci isolated from human infections. | sixty-nine haemolytic and non-haemolytic streptococcal strains were isolated from various human infections and serogrouped with the coagglutination test. the amount of 125i-fibronectin bound to bacterial cells in a standard assay was determined. most of the group a, c, and g strains were able to bind fibronectin. none of the group b or d strains bound significant amounts of fibronectin. group a, c, and g streptococci appear to preferentially bind the n-terminal region of the fibronectin molecule ... | 1982 | 6297884 |
| homologous interference by avian infectious bronchitis virus, inhibition of plaque formation of the beaudette-42 strain by mixed inoculation with the kh strain. | inhibition of plaque formation by avian infectious bronchitis virus (ibv) beaudette-42 (be-42) strain occurred in chick kidney cells with the inoculation of the same cell culture with the kh strain of ibv. for the complete inhibition of approximately 10(2) plaque-forming units (pfu) of the be-42 strain, at least 10(5) pfu of the kh strain was required. the kh strain would inhibit plaque formation by the be-42 strain if used as long as six hours after the inoculation of the be-42 strain. the inac ... | 1983 | 6300978 |
| comparative vector competence of culex tarsalis and culex quinquefasciatus from the coachella, imperial, and san joaquin valleys of california for st. louis encephalitis virus. | st. louis encephalitis (sle) virus has continued to be active in the colorado desert region of southern california (coachella and imperial valleys) since 1973, while it has virtually disappeared from the sacramento and san joaquin valleys of central california. consequently, comparative vector competence studies were undertaken from 1978 to 1981 to evaluate the susceptibility of populations of culex quinquefasciatus and culex tarsalis from the san joaquin and coachella/imperial valleys to oral i ... | 1983 | 6301301 |
| [insertion of transposon tn9 into the spinal (escherichia coli-saccharomyces cerevisiae) plasmids and the expression of the prokaryotic gene of chloramphenicol resistance in yeast cells]. | transposon tn9 carrying camr gene which controls resistance to chloramphenicol has been introduced in vivo (in cells of escherichia coli) into two chimeric shuttle plasmids pyf91 and yep13. these plasmids consist of the different parts of the e. coli plasmid pbr322, the yeast 2mkm dna plasmid and the yeast leu2 structural gene. the plasmidis able to autonomously replicate in both yeast and bacterial cells. a recipient yeast strain carrying cams and leu2 markers was constructed to study the funct ... | 1983 | 6305766 |
| transductional construction of a threonine-hyperproducing strain of serratia marcescens: lack of feedback controls of three aspartokinases and two homoserine dehydrogenases. | to construct a threonine-hyperproducing strain of serratia marcescens sr41, the six regulatory mutations for three aspartokinases and two homoserine dehydrogenases were combined in a single strain by three transductional crosses. the constructed strain, t-1026, carried the lysc1 mutation leading to lack of feedback inhibition and repression of aspartokinase iii, the thra1(1) mutation desensitizing aspartokinase i to feedback inhibition, the thra2(1) mutation releasing feedback inhibition of homo ... | 1983 | 6307143 |
| mapping of the gene specifying aminoglycoside 3'-phosphotransferase ii on the pseudomonas aeruginosa chromosome. | we examined the aminoglycoside inactivation enzymes in pseudomonas aeruginosa strains, seven clinical isolates and seven laboratory strains without plasmids. all strains were found to possess the enzyme aminoglycoside 3'-phosphotransferase ii [aph(3')-ii]. we isolated an aph(3')-ii-deficient mutant from a pao strain by mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine. by plasmid (fp5 or r68.45)-mediated conjugation, we determined the locus of the gene specifying the aph(3')-ii between trp-6 ... | 1983 | 6307974 |
| expression of eight unrelated muc+ plasmids in eleven dna repair-deficient e. coli strains. | 23 plasmids from different incompatibility groups were tested for their ability to increase post-uv survival and uv-induced reversion to arg+ in escherichia coli strain ab1157 arge3 8 plasmids increased mutagenesis, of which 7 increased uv resistance. the exception, plasmid r391, sensitized ab1157 to uv. all 8 plasmids were absolutely dependent upon host reca+ and lexa+ genotypes for expression of these functions, but were independent of uvra+, uvrb+, umuc+, recf+, pola+, uvrd+ or recl+. e. coli ... | 1983 | 6314133 |
| single amino acid substitution in 30k protein of tmv defective in virus transport function. | involvement of the tobacco mosaic virus (tmv) coded 30k protein in a virus transport function within the infected plant has been suggested. previously a temperature sensitive mutant, tmv ls 1, that is defective in cell-to-cell movement at a restrictive temperature, was reported. to demonstrate a relationship between the 30k protein and the transport function, the nucleotide sequences of the 30k and coat protein cistrons of the mutant, tmv ls 1, and the wild type, tmv l (tomato strain) were compa ... | 1983 | 6316652 |
| direct selection for gene replacement events in yeast. | a method that facilitates gene replacement at the his3 locus of saccharomyces cerevisiae (yeast) has been developed. first, an internal region of the cloned his3 gene was replaced by a dna segment containing the wild-type ribosomal protein gene, cyh2. second, by using standard yeast transformation methods, the wild-type his3 locus of a cycloheximide resistant strain (cyh2r) was replaced by this his3-cyh2 substitution. the resulting strain is sensitive to cycloheximide because cyh2 is dominant to ... | 1983 | 6323262 |
| [cloning of genetic material in bacillus]. | plasmid vectors capable for propagation of bacillus subtilis dna fragments containing riboflavin genes were constructed. cloning of rib operon using pub110 derivatives was performed in rece4 strain by using sequentional rescue of plasmids containing subfragments of the operon. also, rib operon was cloned on the vectors containing dna repeats. it was shown that the presence of direct and inverted repeats within plasmids allows to transform b. subtilis cells by monomers of plasmid dna. vectors tha ... | 1984 | 6323972 |
| recombinant nontoxinogenic vibrio cholerae strains as attenuated cholera vaccine candidates. | an ideal vaccine does not yet exist to prevent cholera, a significant health problem in many less developed countries. vibrio cholerae, the agent of epidemic and endemic cholera, colonizes the small bowel and secretes a potent enterotoxin that consists of a single a subunit, which stimulates adenylate cyclase activity, and five identical b subunits which bind to the ganglioside gm1 receptor of intestinal mucosal cells. previous studies in man indicate that toxoid-derived antitoxic immunity by it ... | 1984 | 6324005 |
| antigenic and biochemical characterization of poliovirus type 1 isolates of non-vaccine origin. | during the past 15 years, five poliovirus type 1 strains with non-vaccine-like antigenicity have been isolated in japan. of these isolates, two were from paralytic poliomyelitis patients not associated with the use of sabin vaccine, and three were apparently introduced from abroad. all the isolates could be readily distinguished from the corresponding sabin type 1 vaccine strain by oligonucleotide mapping of the viral rna and by polyacrylamide gel electrophoresis of the viral proteins. the oligo ... | 1983 | 6328228 |
| new mutation (mmra1) in escherichia coli k-12 that affects minimal medium recovery and postreplication repair after uv irradiation. | after uv irradiation, escherichia coli uvra mutant cells show higher survival on minimal than on rich growth medium, i.e., they show minimal-medium recovery. this effect of rich growth medium on survival is not observed in a uvra mutant carrying an mmra1 mutation, and the uvra mmra strain showed the same survival rate on minimal and rich growth media as the uvra strain did on minimal medium plates. the mmra1 mutation was isolated as a hidden mutation from a uvra pola mutant strain and shown to m ... | 1983 | 6341360 |
| genetic and biochemical analyses of escherichia coli strains having a mutation in the structural gene (poxb) for pyruvate oxidase. | mutants of escherichia coli k-12 deficient in pyruvate oxidase were isolated from an aceef (pyruvate dehydrogenase-deficient) strain by selection for a complete absence of growth on medium lacking acetate. extracts of two of the mutants were shown to contain normal levels of pyruvate oxidase antigen, although the enzymatic activities of the extracts were reduced or absent. the poxb locus was mapped by using closely linked transposon insertions to min 18.7 of the e. coli linkage map between the c ... | 1983 | 6341362 |
| [activity of intracellular enzymes in bacillus thuringiensis prospores and sporangia]. | the activity of endocellular enzymes (alkaline phosphatase, protease, glucose dehydrogenase, aldolase, malate dehydrogenase, nadh dehydrogenase, nadh oxidase) was studied in isolated prospores and sporangia as well as in vegetative cells of bacillus thuringiensis strains, one of which produced crystals and one did not. the activity of malate dehydrogenase and nadh dehydrogenase was high in prospores of the both strains at the fifth and sixth stages of spore formation. the strain which did not pr ... | 1983 | 6341786 |
| involvement of a plasmid in escherichia coli envelope alterations. | a plasmid-containing wild-type escherichia coli strain was treated with two plasmid-curing agents, sodium dodecyl sulfate and ethidium bromide. plasmid elimination was accompanied by drastic changes in the morphology of the colonies. analysis of the cured strain by scanning and transmission electron microscopy showed important alterations in size and morphology of the cells. metabolic differences were also found between the wild-type and cured cells. | 1983 | 6345508 |
| hipa, a newly recognized gene of escherichia coli k-12 that affects frequency of persistence after inhibition of murein synthesis. | except for a small fraction of persisters, 10(-6) to 10(-5), escherichia coli k-12 is killed by prolonged inhibition of murein synthesis. the progeny of persisters are neither more resistant to inhibition of murein synthesis nor more likely to persist than normal cells. mutants have been isolated in which a larger fraction, 10(-2), persists. the persistent response of the mutants, hip (high persistence), is to inhibition of murein synthesis at early or late steps by antibiotics (phosphomycin, cy ... | 1983 | 6348026 |
| isolation of mannan-protein complexes from viable cells of saccharomyces cerevisiae x2180-1a wild type and saccharomyces cerevisiae x2180-1 a-5 mutant strains by the action of zymolyase-60,000. | the viable whole cells of saccharomyces cerevisiae x2180-1a wild type and its mannan mutant strain s. cerevisiae x2180-1a-5, were treated with an arthrobacter sp. beta-1,3-glucanase in the presence of a serine protease inhibitor, phenyl-methylsulfonyl fluoride. fractionation of the solubilized materials of each strain with cetavlon (cetyltrimethylammonium bromide) yielded one mannan-protein complex. molecular weights of these complexes were almost the same as that of the mannoprotein of the muta ... | 1983 | 6355061 |
| detection of antibodies against legionella pneumophila serogroups 1 to 6 and the leiden-1 strain by micro elisa and immunofluorescence assay. | one hundred and seventy-five human sera were tested for the presence of type-specific antibodies against l pneumophila serogroups 1 to 6 and the leiden-1 strain by means of an enzyme linked immunosorbent assay (elisa) and compared with the results obtained by the indirect immunofluorescence assay (ifa). a high correlation (correlation coefficient 0.92) between both methods was found. no consistent pattern of igg, iga and igm classes of antibody titres against l pneumophila were found. in the ser ... | 1983 | 6355195 |
| increase in specific opsonic activity in bovine milk following experimental escherichia coli mastitis. | an infection in a single bovine mammary quarter with a capsulated escherichia coli stimulated a long lasting opsonic activity for the phagocytosis and killing of the homologous strain by polymorphonuclear leucocytes. the induced activity was associated with increases in the igm fraction and an appearance of activity in the igg2 fraction. the capsular polysaccharide was the major inducing antigen, with the immune whey showing opsonic activity for other strains of e coli with antigenically similar ... | 1983 | 6356257 |
| comparison of the escherichia coli umu+-encoded function with plasmid r46-mediated error-prone repair in dna-damaged cells. | escherichia coli strain tk701 umu+ was more resistant than strain tk702 umu when tested against bleomycin (blm), cis-platinum(ii) diamminodichloride (pdd), ultraviolet light and methyl methanesulphonate (mms), which produce single-strand dna damage. however, the umu mutant was no more sensitive to mitomycin c (mtc) or proflavine (pf), which cause double-strand dna binding. strain tk702 umu was nonmutable by any of the agents, whereas mutations were induced in the wild-type strain by pdd, uv, mms ... | 1984 | 6366535 |
| comparative pathogenicity of auxotrophic mutants of candida albicans. | an induced mutant of candida albicans with greatly decreased virulence for mice is described. the mutant was one of five auxotrophic mutants obtained by ultraviolet irradiation of a clinical isolate (strain my 1044). the five mutants included two methionine auxotrophs, one methionine-cysteine auxotroph, one temperature-sensitive serine auxotroph, and one auxotroph with unknown growth requirements. each of the mutants produced normal mycelium and had a normal profile of susceptibility to four ant ... | 1984 | 6370397 |
| cloning and expression of a yeast copper metallothionein gene. | the induction of a copper-binding metallothionein (cu-mt) was studied in yeast, saccharomyces cerevisiae, and a relationship between copper resistance and intracellular levels of cu-mt in these eukaryotes was established. poly(a)-containing rna from a copper-resistant (cur) yeast strain, which synthesized abundant quantities of cu-mt and in which cu-mt gene transcription was enhanced 50-fold upon exposure to cuso4, was used to screen yeast genomic dna clones. restriction analysis revealed common ... | 1984 | 6370791 |
| barrier effect of bifidobacterium longum on a pathogenic escherichia coli strain by gut colonization in the germ-free rat. | the predominance of bifidobacteria in normal breast-fed babies is well established. even under unfavourable hygienic conditions of delivery and during the breast-feeding period bifidobacteria develop and colonize the intestinal tract at high concentrations. in the present study we investigated the interaction between bifidobacterium longum and a pathogenic e. coli strain in the germ-free rat. sequential counts of the two bacterial strains allowed their proliferation to be followed. electron micr ... | 1984 | 6372273 |
| biochemical and antibacterial properties of bovine mammary secretion during mammary involution and at parturition. | mammary secretions from four holstein friesian cows were collected during late lactation, early involution, and early in subsequent lactation. changes of ph, concentration of serum albumin, immunoglobulin g, citrate, lactoferrin, and number of leukocytes in secretions were typical of milk from glands undergoing these physiological transitions. whey prepared from a cow's secretions was evaluated for its capacity to inhibit growth of escherichia coli, 60-lilly, and a coliform strain isolated from ... | 1984 | 6397483 |
| immunochemical properties of mannan-protein complex isolated from viable cells of saccharomyces cerevisiae 4484-24d-1 mutant strain by the action of zymolyase. | viable cells of saccharomyces cerevisiae 4484-24d-1 mutant strain were treated with an arthrobacter sp. beta-1,3-glucanase, zymolyase-60,000, in the presence of a serine protease inhibitor, phenylmethylsulfonyl fluoride. fractionation of the solubilized materials with cetavlon (cetyltrimethylammonium bromide) yielded a purified mannan-protein complex, which had a molecular weight of ca. 150,000, approximately three times higher than that of the mannan isolated from the same cells by the hot-wate ... | 1984 | 6398395 |
| lysis of nitrofurantoin-resistant strain of vibrio el tor. | both nitrofurantoin-sensitive and nitrofurantoin-resistant strains of vibrio el tor were found to lyze in the presence of tris-edta at alkaline ph. the rate of lysis was appreciably enhanced by lysozyme. the amounts of intracellular components, viz. proteins and carbohydrates, released from the nitrofurantoin-sensitive strain by tris-edta treatment, were significantly lower than those from the nitrofurantoin-resistant strain. differences in periplasmic proteins released from tris-edta treated ce ... | 1983 | 6403416 |
| dna interference with radioimmunoassay procedures. | a bacterial factor preventing precipitation of immune complexes was purified from a culture of streptococcus faecalis (ak strain) by gel filtration on sephadex g-100 and bio-gel a-150m columns. the factor was identified as dna on the basis of its ultraviolet absorption maximum at 260 nm, hydrolysis by deoxyribonuclease, mr exceeding 1.5 x 10(8), and positive reaction with diphenylamine. dna interferes with the immunoassay by preventing precipitation of immune complexes. only double-stranded dna ... | 1983 | 6414736 |
| [regulation of the enzyme activity of para-xylene catabolism in a spontaneous para-xylene-negative variant of pseudomonas aeruginosa 2x79]. | a spontaneous variant of pseudomonas aeruginosa 2x unable to grow on p-xylene as the sole source of carbon and energy has been isolated. p-xylenenegative variant of p. aeruginosa 2x79 differs from the wild type strain by the character of growth on the p-xylene oxidation intermediates p-toluate and protocatochuate. the cell of 2x79 variant inability to grow on p-xylene has been shown to be accompanied by the elimination of the activities of three enzymes - p-xylene methylhydroxylase, p-cresol met ... | 1983 | 6418220 |
| malate dehydrogenase isozymes in schistosoma japonicum (chinese mainland strain) by electrophoresis. | | 1983 | 6418450 |
| restoration of ligase activity in e. coli k12 lig ts7 strain by bacteriophage mu and cloning of a dna fragment harbouring the mu 'lig' gene. | restoration of ligase activity has been observed in e. coli k12 ligts7 strain lysogenic for mu, in presence as well in absence of lysogenic immunity. this restoration consist in phenotypic reversal of temperature sensitivity of e. coli ligts7 which also regain the ability to sustain the complete growth cycle of t4 lig-phages. it is possible to put under the control of the gal operon the expression of the viral gene responsible for the restoration effect. this new gene of mu has been named 'lig'. ... | 1980 | 6449688 |
| passive enhancement of rat heart allografts by xenogeneic antidonor sera raised in rabbits. | antilymphocyte serum (als) was raised in rabbits immunized by administration of lymphoid cells from sprague-dawley (spd) rats. the als was rendered specific for the spd strain by complete absorption by wistar rat lymphoid cells. the specificity was considered to be predominantly directed to spd ir gene-associated (ia) antigens, since absorption by spd erythrocytes failed to abolish lymphocytotoxic activities. alloantibody production by wistar rats sensitized with spd spleen cells was completely ... | 1982 | 6460361 |
| effects of triiodothyronine treatments on body and organ growth and the development of immune function in dwarf chickens. | the effects of triiodothyronine (t3) treatments on general body growth, long bone growth, primary lymphoid organ development, antibody production, and serum growth hormone (gh) and thyroid hormone levels were examined in two dwarf strains (sex-linked dwarf--sld, and autosomal dwarf--adw) and in a normal-growing control strain (k) of white leghorn chickens. one-day-old male chicks from each of these strains were assigned to either an untreated control group or to one of the groups receiving a t3 ... | 1984 | 6473358 |
| influence of phase feeding available phosphorus on egg production characteristics, carcass phosphorus content, and serum inorganic phosphorus levels of three commercial layer strains. | an experiment was conducted to obtain information on the concept of progressively decreasing dietary phosphorus levels (phase feeding) on the performance of three different commercial layer strains. dietary available phosphorus (ap) levels of .15, .30, or .45% were fed continuously from 22 to 70 weeks of age. concurrently, a diet containing .35, .25, and .15% ap was phase-fed during age intervals of 22 to 34, 34 to 50, and 50 to 70 weeks, respectively. dietary ap levels did not significantly aff ... | 1984 | 6483720 |
| biological properties and dog response to a variant (m-) strain of brucella canis. | wild type (virulent) b. canis organisms are always rough and growth becomes extremely mucoid (m+) after several days of incubation, especially on media ph 7.2. the mucoid growth of virulent (m+) b. canis and the marked tendency for m+ bacteria, and extracted cell wall antigens, to aggregate at acid ph (ph less than 6.5) are markedly diminished in a less mucoid (m-) variant. the m+ and m- brucella, and their extracted cell wall antigens, also differ in hydrophobic properties; the m+ organisms (an ... | 1984 | 6489639 |
| pneumonia due to chlamydia trachomatis in japanese infants. | sera from 109 japanese infants with pneumonia were tested for antibody to chlamydia trachomatis (c. trachomatis) l2 strain by an indirect immunofluorescence (if) technique. nasopharyngeal swabs were also collected to isolate c. trachomatis. clinical specimens were inoculated onto cycloheximide-treated mccoy cells and deae-dextran-treated hela 229 cells. of 109 patients, 32 (29%) were positive for igm antibodies (titer, greater than or equal to 1:16) to c. trachomatis. c. trachomatis was isolated ... | 1984 | 6495321 |
| isolation and identification of two hemolytic forms of streptolysin-o. | streptolysin-o was isolated from culture supernatants of group-a beta-hemolytic streptococci (richards strain) by ammonium sulfate and polyethylene glycol precipitation, deae-ion exchange chromatography, preparative isoelectric focusing, and chromatography on sephacryl s-300. two forms of the toxin possessing similar hemolytic capacity were identified. the native toxin was a single polypeptide chain devoid of amino sugars with a sedimentation coefficient of 3.9s and a molecular weight of 69,000, ... | 1984 | 6500696 |
| cross adaption between stress and cold in rats. | three-hour immobilization stress was imposed on male adult rats of wistar strain by restraining them on a board 6 days a week for 1-8 weeks. the stressed rats showed less body weight gain during the experiment compared to the controls. these stressed animals manifested an improved cold tolerance as shown by no significant fall in colonic temperature in the cold at -5 degrees c for 300 min during the experimental period, while the colonic temperature of the controls fell progressively. nonshiveri ... | 1984 | 6522247 |
| utilization of plasmid pulb113 (rp4::mini-mu) to construct a linkage map of erwinia carotovora subsp. chrysanthemi. | we report experimental evidence that pulb113, an rp4::mini-mu plasmid, mediates chromosome transfer in a strain of erwinia carotovora subsp. chrysanthemi which does not accept the f episome. this allowed us to construct a genetic map of that strain by measuring the frequencies of cotransfer of different markers (thy, leu, pro, [his, trp], thya, rpsl, ile). | 1983 | 6574127 |
| nosocomial spread of haemophilus influenzae type b infection documented by outer membrane protein subtype analysis. | this report provides evidence of nosocomial transmission of haemophilus influenzae type b infection between two children in an acute care hospital. in the past, transmission of infection between these children would have gone unrecognized, because the isolates from the respective cases differed in susceptibility to ampicillin. however, the outer membrane protein profile of the two isolates was identical and has previously been observed in less than 2% of type b haemophilus isolates from patients ... | 1983 | 6602214 |
| [antigenic drift of a strain of influenza equi virus isolated in france during the winter of 1978-1979]. | a strain of influenza equi virus isolated during winter 1978-1979 has been compared with influenza a/equine/miami/1/63 (h3n8) strain by cross reactions performed by radial haemolysis (rh) and hemagglutination inhibition (hai) test. specific antisera were prepared on hens and guinea-pigs. results differed according to the species on which the sera were prepared and the two methods of titration of the antibodies. hens sera were unable to differenciate by hai the newly-isolated strain influenza a/e ... | 1983 | 6614786 |
| attachment and internalization of a chlamydia trachomatis lymphogranuloma venereum strain by mccoy cells: kinetics of infectivity and effect of lectins and carbohydrates. | the kinetics of attachment and ingestion of chlamydia trachomatis serotype l1 by monolayers of mccoy cells were studied by using a method that discriminated between attachment and uptake. when about 1% of the mccoy cells was infected, the proteinase k-resistant chlamydial fraction, regarded as ingested chlamydiae, reached a constant value after about 3 h of incubation at 37 degrees c. uptake of chlamydiae at 4 degrees c could not be demonstrated. the attached and ingested chlamydial fractions we ... | 1983 | 6642670 |
| transepithelial chemotaxis of rat peritoneal exudate cells. | the migration of peritoneal exudate (pe) cells into plain millipore filters mounted in boyden chambers occurs under random, chemokinetic and chemotactic conditions. significant migration of such cells in vivo, however, involves both transendothelial and transepithelial penetration and occurs predominantly under pathological conditions where chemotactic agents are presumed to be present in gradient form. when madin-darby canine kidney (mdck) epithelial cells are grown as a confluent monolayer on ... | 1983 | 6661396 |
| [several regularities of the interrelation of blood leukocytes and microbes in the infectious process]. | the rate of absorption by polymorphonuclear leukocytes of different strains of staphylococci present in a homogeneous mixture was studied. the cells of one of the strains were radiolabeled and this made it possible to differentiate them from the cells of another strain by means of electron microscopic autoradiography. different rates of absorption of cocci belonging to different strains by leukocytes of normal subjects and by those from patients with sepsis resulting from burn or wound were obse ... | 1983 | 6670937 |
| legionella bozemanii serogroup 2: a new etiological agent. | a newly discovered bacterium, toronto 3, isolated from a lung aspirate of a patient with pneumonia, has been characterized. the isolate was identified as legionella bozemanii by chemical data from cellular fatty acid and ubiquinone analyses and by dna relatedness studies. the isolate, however, differs phenotypically from l. bozemanii by its colonial characteristics and strong interspecies serological cross-reactions, which are unique among clinical isolates of legionellae. the name l. bozemanni ... | 1984 | 6690465 |
| compared colonizing and immunizing efficiency of toxinogenic (a+ b+) vibrio cholerae and an a- b+ mutant (texas star-sr) studied in adult rabbits. | four strains of vibrio cholerae o1 were compared for their ability to colonize and immunize adult rabbit intestine. three were virulent, toxinogenic (a+ b+) isolates, and one, an a- b+ mutant (texas star-sr), was derived by mutagenesis with nitrosoguanidine. when given orally to nonimmune rabbits, virulent strains colonized the small bowel with similar efficiency, whereas texas star-sr colonized poorly. rabbits fed less than 50 cfu of an a+ b+ strain developed marked serotype-specific resistance ... | 1984 | 6715038 |
| glucose phosphoenolpyruvate-dependent phosphotransferase system of streptococcus mutans gs5 studied by using cell-free extracts. | the glucose phosphotransferase system (pts) of streptococcus mutans gs5 has been partially characterized, using fractions derived from cells treated with the muramidase mutanolysin. membranes retained functional pts enzymes for the phosphoenolpyruvate-dependent phosphorylation of glucose, fructose, and mannose. this was confirmed by assaying membranes directly for enzyme i (ei) and enzyme iiglc (eiiglc) by employing specific phosphoryl-exchange reactions for each factor. membranes prepared from ... | 1984 | 6715047 |
| [characteristics of long-term persisting strains of tick-borne encephalitis virus in different forms of the chronic process in animals]. | the properties of the vasilchenko strain of tick-borne encephalitis (tbe) virus and its 3 variants isolated at various stages of persistent infection (383, 453, and 535 days) in macaca rhesus monkeys and syrian hamsters with different forms of the chronic tbe were studied. the process characterized by chronic focal inflammatory-degenerative changes in the brains of hamsters without the disturbance of motor functions was associated with persistence of different kinds of virus-specific antigens wi ... | 1982 | 6753337 |
| [developmental cycle and the cytomorphological characteristics of the oleandomycin producer streptomyces antibioticus]. | the developmental cycle and cytomorphological features of the industrial strain ol-1 and its variant 0968 of the oleandomycin-producing organism were studied. variant 0968 was obtained as a result of exposure of the spores of strain ol-1 to uv light. when grown under submerged conditions in flasks with the rich medium, the strains were characterized by a complete developmental cycle consisting of three generations of the hyphae. every generation had a tendency for formation of submerged spores. ... | 1982 | 6756297 |
| pyomelanin production by pseudomonas aeruginosa. i. transformation of pyomelanin productivity. | pseudomonas aeruginosa was successfully transformed from a pyomelanin-producing strain to a non-pyomelanin-producing strain by genetic transformation, with an average frequency of 1.17 x 10-3/recipient. although the transformation frequency was not affected by doses of dna between 17 and 51 microgram/ml, it was influenced by the growth phase of the recipient bacteria, i.e., it was highest in the late logarithmic phase. biochemical functions of the transformants were the same as those of the reci ... | 1980 | 6767172 |
| mouse-protection experience with monovalent pseudomonas aeruginosa vaccine. | the protective effect of the soluble immunogenic complex from pseudomonas aeruginosa cell surface was studied on white mice. vaccines were prepared from a single strain by phenol-water extraction or via preparing the zn-complex. the immunogenic complex which contained the pseudomonas "common protective antigen" as well as endotoxin and exotoxins in the form of toxoid, provided reliable protection if it was administered with aluminium hydroxide as adjuvant in three consecutive doses of 10, 100 an ... | 1980 | 6775443 |
| immunological relationship between strains of theileria annulata dschunkowsky and luhs 1904. | the immunological relationship between the ludhiana and hissar strains, and between the uruli-kanchan, bangalore and jaipur strains of theileria annulata was studied. calves were immunised against the ludhiana strain by the infection-treatment method, against the uruli-kanchan strain by the infection-treatment method or by untreated low-grade infection and against the jaipur strain by untreated low-grade infection. after 45 days, groups of immune calves and susceptible controls were challenged w ... | 1980 | 6779361 |
| studies on the cross-resistance of mycobacterium tuberculosis, strain h37rv, to aminoglycoside- and peptide-antibiotics. | various phenotypes of the resistance to aminoglycoside- and peptide-antibodies of mycobacterium tuberculosis strain h37rv were produced by single- and/or two-step selection of the parent strain. mutants obtained by single-step selection with antibiotics were classified into ten phenotypes; one of single resistance, two of triple resistance, three of quadruple resistance, and four of sextuple resistance. there were two kinds of sextuple resistance (high resistance to enviomycin, viomycin, capreom ... | 1980 | 6783817 |
| inhibition of uridine 5'-diphosphate-n-acetylmuramyl-l-alanine synthetase by beta-chloro-l-alanine in escherichia coli. | the synthesis of the nucleotide precursors for peptidoglycan is regulated by the rela gene in escherichia coli. thus, nucleotide precursors labeled with [3h]diaminopimelic acid accumulated in a rela strain but not in an isogenic rela+ strain during amino acid deprivation. furthermore, nucleotide precursor synthesis was relaxed in the amino acid deprived rela+ strain by treatment with chloramphenicol. uridine diphosphate-n-acetylmuramyl-pentapeptide (udp-murnac-pentapeptide) was the major compone ... | 1982 | 6811120 |
| facile in vivo transfer of mutations between the bacillus subtilis chromosome and a plasmid harbouring homologous dna. | transformation of bacillus subtilis strains carrying the point mutations spoiia42 or spoiia69 by a plasmid, phm2, carrying the spoiia+ allele gave occasional recombinants in which the plasmid had acquired the chromosomal mutation. transformation of a spo+ strain by these derivative plasmids gave occasional recombinants in which the chromosome of the recipient had acquired the plasmid-borne spoiia mutation. both types of behaviour were rece+-dependent. mutations spoiia42 and spoiia69 fell into a ... | 1982 | 6818329 |
| [production of the mutant e strain of rickettsia prowazekii by mutagen exposure]. | the possibility of obtaining the mutants of r. prowazekii, strain e, by exposing these organisms to the action of n-methyl-n-nitro-n-nitrosoguanidine was studied; this substance, used in doses of 5-10 micrograms, showed a mutagenic effect on rickettsiae suspended in physiological saline, after their exposure for 10-20 minutes at 37 degrees c. the mutants thus obtained proved to be resistant to erythromycin and rifampicin and were characterized by heterogeneity in the degree and stability of thei ... | 1982 | 6818794 |
| transferable resistance to clindamycin, erythromycin, and tetracycline in clostridium difficile. | resistance to clindamycin, erythromycin, and streptogramins in clostridium difficile could be transferred to a susceptible strain by mixed culture at low frequencies (1 x 10(-8) to 4 - 10(-8) per donor cell). transfer of tetracycline resistance occurred at frequencies of 3 x 10(-7) to 5 x 10(-7). no plasmid dna involved in these transfers could be detected. | 1983 | 6870225 |
| the development of a sex-linked slow-feathering white leghorn strain by gene transfer from an indian indigenous breed. | breeding techniques were used to transfer an economically important physiological character dependent on a single pair of alleles from an indigenous breed (kadakanath) to the white leghorn. the mating procedure used to develop a sex-linked, slow-feathering strain of white leghorn by these means is described and it is shown that using the simplest genetic and breeding techniques productivity can quickly be improved. | 1983 | 6883154 |
| isolation of bacterial luciferases by affinity chromatography on 2,2-diphenylpropylamine-sepharose: phosphate-mediated binding to an immobilized substrate analogue. | a covalently immobilized form of an inhibitor of bacterial luciferase, 2,2-diphenylpropylamine (d phi pa), was an effective affinity resin for purifying this enzyme from several distinct bacterial species. the inhibitor is competitive with the luciferase aldehyde substrate but enhances binding of the flavin substrate fmnh2 (reduced riboflavin 5'-phosphate); comparable binding interactions occur with luciferase, the immobilized inhibitor d phi pa-sepharose, and the substrates [holzman, t. f., & b ... | 1982 | 6983889 |
| analysis of outer membrane components of escherichia coli ml308 225 and of a serum-resistant mutant. | escherichia coli ml308 225 in the early exponential phase of batch cultures was killed by human serum in a complement-dependent reaction. under the same conditions, a mutant derived from this strain by multiple subcultures in human serum was resistant to killing by serum. the components of the outer membrane of both the parent and mutant strains were analyzed. the protein and phospholipid analyses were identical, but the mutant strain produced twice as much lipopolysaccharide as the parent strai ... | 1980 | 6995308 |
| antigenicity in hamsters of inactivated vaccines prepared from recombinant influenza viruses. | inactivated vaccines prepared form influenza virus strains obtained by the recombination of a/pr/8/34 (h1n1) or a/fm/1/47 (h1n1) viruses with a/victoria/3/75 (h3n2) virus, were tested for their antigenicity in hamsters. the parental origin of the genes of each cloned recombinant virus was determined by polyacrylamide gel electrophoresis, and vaccines prepared from each strain by concentration, purification on sucrose density gradients and inactivation with formalin. all the recombinant strains u ... | 1981 | 7031128 |
| treatment of acute myelogenous leukemia: influence of three induction regimens and maintenance with chemotherapy or bcg immunotherapy. | the effect of a synchronizing-recruiting drug schedule vs. myelotoxic therapy on remission rate and of bacillus calmette-guerin on remission duration and survival of adults with acute myelogenous leukemia were studied in a prospective cooperative trial. after randomized remission induction with arabinosyl cytosine + vincristine + methotrexate + leucovorin (avml), thioguanine + ara-c + daunorubin (tad), or daunorubicin + ara-c (da), complete remissions (cr) were consolidated with tad or avml. crs ... | 1982 | 7039813 |
| metabolic basis for the isoleucine, pantothenate or methionine requirement of ilvg strains of salmonella typhimurium. | salmonella typhimurium strain du501, which was found to be deficient in acetohydroxy acid synthase ii (ahas ii) and to possess elevated levels of transaminase b and biosynthetic threonine deaminase, required isoleucine, methionine, or pantothenate for growth. this strain accumulated alpha-ketobutyrate and, to a lesser extent, alpha-aminobutyrate. we found that alpha-ketobutyrate was a competitive substrate for ketopantoate hydroxymethyltransferase, the first enzyme in pantothenate biosynthesis. ... | 1982 | 7042686 |
| tetracycline-inducible transfer of tetracycline resistance in bacteroides fragilis in the absence of detectable plasmid dna. | tetracycline resistance of three bacteroides fragilis strains was shown to be inducible by subinhibitory concentrations of tetracycline. tetracycline resistance markers could be transferred to another b. fragilis strain by filter mating. the transferability was inducible by subinhibitory concentrations of tetracycline and did not take place in the absence of tetracycline. the optimum concentration of tetracycline for induction of transfer was about 2 microgram/ml. the transfer was shown to be a ... | 1982 | 7061390 |
| protection of mice from infection with streptococcus pneumoniae by anti-phosphocholine antibody. | anti-phosphocholine (pc) antibody mediated protection against many strains of streptococcus pneumoniae, and hybridoma anti-pc antibodies protected mice from fatal infections with types 1 and 3 s. pneumoniae. live types 1, 3, 5, 6a, and 19f s. pneumoniae had similar amounts of surface pc accessible to antibody. furthermore, mice expressing the x-linked immunodeficiency (xid) of the cba/n strain were found to be more susceptible to infection with s. pneumoniae of types 3, 6a, and 19f than were imm ... | 1982 | 7076292 |
| estrogen and progesterone receptors in mammary tumors induced in rats by simultaneous administration of 17 beta-estradiol and progesterone. | mammary tumors were promoted in male rats of the wistar wag strain by continuous and simultaneous administration of 17 beta-estradiol and progesterone. tumor induction and growth were dependent on estradiol and on progesterone. their histological features were comparable with those of human breast cancers. hormone receptors were present in tumor cells. estradiol receptor was found in 95% of them, at a higher level in nuclei than in cytosol. progesterone receptor was present in 75% of tumors. in ... | 1982 | 7132354 |
| [identification of a new antigenic variant of simian adenovirus sa7 p]. | serological, biological, and physico-chemical properties of a new antigenic variant of simian adenovirus sa7p were studied. neutralization tests with hyperimmune specific antisera demonstrated the new antigenic variant sa7p to have very significant antigenic similarity with the prototype sa7 strain. same as the latter, sa7p does not agglutinate rat red blood cells, is highly oncogenic for newborn syrian hamsters and capable of transforming rat kidney cell cultures. at the same time, the method o ... | 1982 | 7135929 |
| serological differentiation of tobamoviruses by means of monoclonal antibodies. | several serologically related plant viruses have been differentiated for the first time by means of monoclonal antibodies. two orchid strains of tobacco mosaic virus that were previously considered to be serologically identical with the type strain were shown to be distinguishable with certain monoclonal antibodies. in indirect elisa, none of the antibodies showed any binding to tobamoviruses that differed from tmv (common strain) by a serological differentiation index larger than 2. monoclonal ... | 1982 | 7161367 |
| the influence of dietary magnesium on reduction of nephrocalcinosis in rats fed purified diet. | the severity of nephrocalcinosis in female colworth wistar rats fed on a standard purified diet was reduced by increasing the magnesium content of the diet; both its incidence and severity could be increased in males of the same strain by lowering the dietary magnesium level. | 1982 | 7176523 |
| comparative pulmonary tumorigenesis in dba/2j and c57bl/6j mice by administration of 3-methylcholanthrene and dimethylnitrosamine singly and combined. | c57bl/6j mice, which are inducible for both hepatic and pulmonary aryl hydrocarbon hydroxylase (ahh), and dba/2j mice, which are noninducible for hepatic ahh but moderately inducible for pulmonary ahh, received dimethylnitrosamine (dmn) i. p., or methylcholanthrene (mca) orally, or a combination of both agents, for 10 weeks; the animals were observed for an additional 26 weeks. the dosing schedule and total dose of dmn or mca or dmn + mca received were identical to those used by other investigat ... | 1982 | 7177243 |
| [studies on the pheromonal pregnancy block in the mouse. ii. discriminatory and/or memorial mechanisms in female mice responding to the stud male]. | the present study was carried out to examine whether the stud male strain have a blocking effect on the pregnancy in stud female. four inbred mouse strains, c3h, c57bl/6, balb/c and cba, were used in these experiments. virgin female mice were caged together with a male of a different strain at 10-20 weeks of age for copulation. the mated females were removed from the male, and housed with a male strange or alien from the stud male. the "bruce effect" was evident in c3h, balb/c and cba strains, b ... | 1981 | 7262197 |
| suppression of inherent virulence for chickens of a newcastle disease strain by a shift within its subpopulations. | | 1981 | 7271661 |