Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| increase in frequency of appearance of cadmium-resistant cells induced by various tumor promoters; evidence for the induction of gene amplification. | when chinese hamster lung (chl) cells were cultured in medium containing 25 microm cadmium chloride, resistant cells appeared at a frequency of 0.04%. when one of three tumor promoters, 12-o-tetradecanoylphorbol-13-acetate (tpa), aplysiatoxin and dihydroteleocidin b, was added during selection with cadmium chloride, the frequency of appearance of resistant cells increased more than 50-fold. two of the resistant clones obtained were characterized. both clones produced much higher levels of metall ... | 1983 | 6680725 |
| attempts to induce cytogenetic effects with sulphite in sulphite oxidase-deficient chinese hamsters and mice. | chinese hamsters and mice were made sulphite-oxidase deficient by the feeding of a low-molybdenum diet with sodium tungstate as a drinking-water supplement. hepatic sulphite-oxidase activity was checked spectrophotometrically. under normal conditions, sulphite-oxidase activity is high in the mouse and low in the chinese hamster. sulphite (so3--) was given in a single or double oral dose in aqueous solution or dissolved in fruit juice or by repeated subcutaneous injections up to the maximum toler ... | 1983 | 6682075 |
| hyperthermia and thermal tolerance in normal and ataxia telangiectasia human cell strains. | three normal human fibroblast strains, two human ataxia telangiectasia heterozygote cell strains, and two human ataxia telangiectasia homozygote cell strains were studied for their thermal responses between 41.0 and 46.0 degrees. the heat sensitivities of all cell strains were comparable, and all cell strains were relatively heat resistant compared to chinese hamster cells. both normal and ataxia telangiectasia human cells developed thermal tolerance during heating at temperatures less than or e ... | 1983 | 6682697 |
| induction of a novel morphological response in chinese hamster ovary cells by pertussis toxin. | exposing chinese hamster ovary cells in culture to pertussis toxin resulted in a novel clustered growth pattern. the specificity of the response for pertussis toxin was shown by neutralization of the activity with specific anti-toxin antibody, heat lability (80 degrees c for 15 min), and absence of such activity by culture media from nontoxigenic bordetella species. although a lag of at least 16 h was required before clustered growth was seen, exposure to the toxin for as little as 10 min result ... | 1983 | 6682833 |
| [mutagenic action of the dna of the highly oncogenic bovine adenovirus type 3 (bav-3)]. | the induction of mutations to the 6-mercaptopurine resistance has been studied in chinese hamster cells after transfection with highly oncogenic bovine adenovirus type 3 dna (bav-3). a statistically significant increase in the yield of resistant mutants is induced by viral dna after two days expression time. the value of induction varies from 56,12 x 10(-5) to 70,02 x 10(-5). the comparison of the mutagenic activity of dna and the intact viral particles has revealed that the number of dna molecu ... | 1983 | 6683105 |
| x chromosome-induced reversion of chromosome segregation in mouse/chinese hamster somatic cell hybrids. cellular recognition of native and foreign x chromosomes. | the direction of chromosome loss in two sets of mouse-chinese hamster hybrids was compared with the direction of segregation of the same hybrids, to which an additional x chromosome derived from either of the mouse sarcoma lines methaa, methas, or cms4, was introduced at the time of the fusion. the addition of the x chromosome was carried out by substituting in place of the chinese hamster parent a mouse x containing microcell hybrid of the latter. it was found that the addition of an x chromoso ... | 1983 | 6683659 |
| the metallothionein-i gene maps to mouse chromosome 8: implications for human menkes' disease. | we have assigned the structural gene (mt-1) coding for the murine metal-binding protein metallothionein i (mt-1) to mouse chromosome 8 by using a cloned dna probe for mouse mt-1 in combination with a panel of chinese hamster-mouse somatic cell hybrid clones segregating mouse chromosomes. analysis of hybrid cell extracts for the presence of mouse mt-1 or mt-1 mrna revealed concordant segregation of mt-1 with mouse glutathione reductase, an enzyme marker for mouse chromosome 8, but discordant segr ... | 1983 | 6683708 |
| chromosomal localization of the human c-fms oncogene. | a molecular probe was prepared with specificity for the human cellular homologue of transforming sequences represented within the mcdonough strain of feline sarcoma virus (v-fms). by analysis of a series of mouse-human somatic cell hybrids containing variable complements of human chromosomes it was possible to assign this human oncogene, designated c-fms, to chromosome 5. regional localization of c-fms to band q34 on chromosome 5 was accomplished by analysis of chinese hamster-human cell hybrids ... | 1983 | 6684766 |
| [possible mechanisms of the origination of chromosomal restructurings. iii. the role of chromosome association and isolation]. | the kinetics of early appearance of chromosome breaks and exchanges (5-60 min after ionizing irradiation) in pea roots, in primary culture of embryonal fibroblasts of balb mice and in chinese hamster cells biid-ii-faf-28 has been studied. it was found that chromosome resistance to irradiation increases during mitosis as fast as the process of chromosome isolation is advanced (the latter prevents the interchromosome and interchromatid contacts). from the outset of activation of sister chromatids ... | 1983 | 6685086 |
| cellular toxicity in chinese hamster ovary cell cultures. ii. a statistical appraisal of sensitivity with the rabbit alveolar macrophage, syrian hamster embryo, balb 3t3 mouse, and human neonatal fibroblast cell systems. | chinese hamster ovary, rabbit alveolar macrophage, syrian hamster embryo, balb 3t3 mouse, and human neonatal fibroblast cells were employed in a statistical evaluation of the relative sensitivity of the cells to toxic substances. the cells were exposed to 1,2,4-trichlorobenzene, 2,4-dimethylphenol, aroclor 1248, cadmium chloride, lead sulfate, nickel nitrate, lead oxide-coated fly ash, and a fine particulate from coal combustion. a filter-disk technique was used to measure the inhibition of prot ... | 1983 | 6685623 |
| inhibition of retinoid toxicity by rat liver s9 fraction in cultured mammalian cells. | the effects of retinol (rol), retinyl acetate (rac) or retinoic acid (ra) on growth of chinese hamster v79 cells were studied. in addition, the effect of rol on cell growth in the human lymphoid cell line rpmi no. 1788 was examined. cultures were treated with retinoid alone, with retinoid plus s9 mix and with retinoid plus the supernatant of s9 fraction. treatment of rol, rac or ra alone inhibited the growth of both cell lines as evidenced by a dose-dependent decrease of viable cell counts. conc ... | 1983 | 6686081 |
| mutant chinese hamster ovary cells pleiotropically defective in receptor-mediated endocytosis. | populations of chinese hamster ovary cells selected for resistance to diphtheria toxin were found to be highly enriched for mutants deficient in the uptake of lysosomal hydrolases via the mannose 6-phosphate receptor. one doubly defective mutant, dtf 1-5-1, exhibited increased resistance to sindbis virus, although it was able to bind and internalize virus normally. normal production of virus was obtained when, subsequent to virus binding, the mutant was exposed for 2 min to acidic ph. similarly, ... | 1983 | 6300143 |
| the ovary: a target organ for 1,25-dihydroxyvitamin d3. | using both clonal chinese hamster ovary (cho) cells in culture and the hen ovary, we have searched for the presence of specific 1,25-dihydroxyvitamin d3 [1,25-(oh)2d3] receptors. receptor analyses were carried out on high salt cytosols of cho cells and high salt extracts of hen ovarian nuclei that were originally isolated in low salt buffer. both cho and hen ovary contain a specific high affinity 1,25-(oh)2d3 receptor (kd = 10(-10) - 10(-11) m), which sediments (3.3s) in high salt sucrose gradie ... | 1983 | 6291916 |
| evidence for multidrug-resistant cells in human tumor cell populations. | data are presented from two cell culture systems which support the notion that a multi-drug-resistant phenotype occurs in human tumor cell populations. human small cell lung cancer cell lines derived from patients in relapse following intensive combination chemotherapy demonstrate broad cross-resistance to nine standard drugs in vitro. however, analysis of [14c]glucosamine-labeled glycoproteins in the small cell lung cancer cell lines failed to identify any consistent association between a speci ... | 1983 | 6313186 |
| biological actions of nitroarenes in short-term tests on salmonella, cultured mammalian cells and cultured human tracheal tissues: possible basis for regulatory control. | pure synthetic nitropyrene compounds were subjected to a mutation test using salmonella typhimurium ta 98 and ta 100 with and without s9 mix, a metabolic activation system. dinitropyrenes were highly mutagenic. among them, 1,8-dinitropyrene was the most potent mutagen, producing 940,000 revertants of ta 98/micrograms. 1,3,6-trinitropyrene and 1,3,6,8-tetranitropyrene were also highly mutagenic, producing 708,000 and 221,000 revertants/micrograms, respectively. 1-nitropyrene was weakly mutagenic. ... | 1983 | 6337823 |
| photobiological activity of 5,7-dimethoxycoumarin. | some biological properties of 5,7-dimethoxycoumarin (dmc) include dark induced frameshift mutagenesis in bacteria, lethal photosensitization and the formation of sister chromatid exchanges in chinese hamster cells. the number of sister chromatid exchanges per unit of cell lethality produced by dmc is almost the same as observed with 5-methoxypsoralen. | 1983 | 6337864 |
| mutagenicity of the enantiomers of the diastereomeric bay-region benz(a)anthracene 3,4-diol-1,2-epoxides in bacterial and mammalian cells. | enantiomers of the diastereomeric pair of bay-region benz(a)anthracene 3,4-diol-1,2-epoxides in which the benzylic 4-hydroxyl group and epoxide oxygen are either cis (isomer 1) or trans (isomer 2) were evaluated for mutagenic activity in two histidine-dependent strains of salmonella typhimurium, as well as in an 8-azaguanine-sensitive chinese hamster cell line. in strain ta 98 of s. typhimurium, the diol-epoxide with (1s,2r,3r,4s) absolute configuration [(-)-diol-epoxide 2] was the most active i ... | 1983 | 6357432 |
| phosphorylation of h1 histones. | the phosphorylation of h1 histones is reviewed. consideration is given to phosphorylation reactions which occur in both replicating and nonreplicating cells. the available evidence suggests that h1 histones accept phosphate groups at different sites in response to different stimuli. the tentative location of the acceptor sites is summarized, and the effects of site-specific phosphorylation on the conformation of h1 histones in vitro is discussed. the phosphorylation of h1 histones which occurs d ... | 1983 | 6358859 |
| activation of aromatic amines to mutagens by bovine bladder and liver cells. | a bovine bladder cell-mediated mutagenesis system using chinese hamster v79 cells and salmonella typhimurium as target organisms was developed to investigate the capacity of the bladder urothelium to activate chemical carcinogens. bovine bladder epithelial cells can activate the aromatic amines af and 4-abp to intermediates which mutate v79 cells and s. typhimurium ta 98 and ta 100. dmba was mutagenic to v79 cells but not detectably mutagenic to either salmonella strain with bladder cell activat ... | 1983 | 6339223 |
| mutagenicity of 3 structurally related epoxides, with defined stereochemical configuration, in saccharomyces cerevisiae and in v79 chinese hamster cells. | 3 structurally related epoxides, 3,4-epoxycyclohexene, trans-1,2,3,4-diepoxycyclohexane and trans-3,4-epoxycyclohexane-r-1,trans-2-diol (anti isomer) were tested for their ability to induce both point mutation, mitotic gene conversion and recombination in a diploid strain (d7) of the yeast saccharomyces cerevisiae, with and without a mammalian microsomal activation system, and the formation of 6-thioguanine-resistant mutants in v79 hamster cells. genetic effects were related to the alkylating pr ... | 1983 | 6339908 |
| genetic and cytogenetic effects of 1,3-dimethyl-3-phenyl-1-nitrosourea in salmonella typhimurium and chinese hamster v79 cells. | 1,3-dimethyl-3-phenyl-1-nitrosourea (dmpnu) shows no spontaneous decomposition in aqueous buffered solution (ph 7.0) at 37 degrees c over a measuring period of 10 days, but it is directly genotoxic in all assays applied. this compound induces base substitutions in salmonella typhimurium (especially in the plasmid harbouring strain ta 100), gene mutations at the hgprt+ locus of chinese hamster v79 cells, and is a very potent inducer of clastogenic damage and sister chromatid exchanges in v79 cell ... | 1983 | 6340850 |
| comparative mutagenicity of a coal combustion fly ash extract in salmonella typhimurium and chinese hamster ovary cells. | the dichloromethane extract of a coal combustion fly ash sample obtained from an experimental fluidized bed coal combustor was tested for mutagenicity in salmonella typhimurium and cultured chinese hamster ovary (cho) cells. the extract was directly mutagenic in s typhimurium strain ta98 and the nitroreductase deficient strains ta98nr and ta98/1,8dnp6. the mutagenicity observed in ta98nr and ta98/1,8dnp6 was lower than that in ta98. addition of exogenous aroclor 1254-induced rat liver supernatan ... | 1983 | 6343066 |
| comparative genotoxic effects of the cooked-food-related mutagens trp-p-2 and iq in bacteria and cultured mammalian cells. | as part of a major study to evaluate the mutagenicity of chemicals produced during the cooking of foods, we examined the responses of bacteria and cultured chinese hamster cells to the compounds trp-p-2 (3-amino-1-methyl-5h-pyrido[4,3-b]indole) and iq (2-amino-3-methylimidazo[4,5-f]quinoline), constituents identified in cooked beef and fish. in the ames/salmonella tester strain ta1538, both compounds were confirmed to be extremely potent mutagens that were active at levels below 1 ng/plate in th ... | 1983 | 6343852 |
| mutagenicity testing of quinine with submammalian and mammalian systems. | quinine hydrochloride was assayed for genotoxic activity by using 4 different test systems with distinct genetic endpoints. no indications for point mutations were observed in the ames system. in 3 cytogenetic tests performed on small rodents, chinese hamsters showed no genotoxic activity, while inbred strains of mice revealed a dose dependent increase of sces, enhanced incidence of micronuclei and elevated chromatid breaks. | 1983 | 6344334 |
| vinylidene chloride: changes in drug-metabolizing enzymes, mutagenicity and relation to its targets for carcinogenesis. | results of various studies have shown that male swiss webster mice are more susceptible to toxic effects of vinylidene chloride (vdc) than are females of the same mouse strain, females and males of the c57bl mouse strain, chinese hamsters and rats. the main targets of toxicity are kidney and liver. the kidney of male swiss webster mice is the only organ where vdc unambiguously induces tumours. in the present study we have investigated the ability of nadph-foritifed postmitochondrial supernatant ... | 1983 | 6347425 |
| mutagenicity evaluation of amino-oxazoline derivatives using in vitro and in vivo short-term tests. | during routine investigation of potential drugs it was found that 1-methyl-4-(2-oxazoline-2-ylamino)-indazole (1) compound 1 was mutagenic for salmonella typhimurium ta1535 and ta100. the genotoxicity of compound 1 was confirmed by the following in vitro test systems: v79 chinese hamster cells (hgprt-locus), saccharomyces cerevisiae d7 (mitotic gene conversion, mutations, aberrations), and escherichia coli (rec-assay). on the other hand, when compound 1 was tested in vivo (micronucleus test in m ... | 1983 | 6347677 |
| genotoxic properties of 2,4,7-trinitro-9-fluorenone. | the genotoxic effects of 2,4,7-trinitro-9-fluorenone (tnf) were studied in assays employing procaryotic (salmonella typhimurium and escherichia coli) and eucaryotic (saccharomyces cerevisiae, mouse lymphoma l5178y and chinese hamster ovary) cells. the results show that tnf is a potent mutagen for procaryotes. it causes both frame-shift and base-pair substitution mutations, although frame-shift mutations were predominant. in saccharomyces cerevisiae, this compound appeared to be too toxic to perm ... | 1983 | 6348527 |
| cell-mediated mutagenesis of chinese hamster v79 cells and salmonella typhimurium. | in the cell-mediated approach, intact cells metabolically activate the chemical and the genetic end points are measured in cocultivated or coincubated target cells. cell-mediated systems have been used to study fundamental problems in carcinogenesis, such as organ and species specificity of carcinogen activation, and in screening for carcinogenic chemicals. in the studies discussed here, cells from various rat, hamster, or bovine tissues are used to metabolically activate the chemical, and mutat ... | 1983 | 6349478 |
| effects of some sugar alcohol derivatives on mutation and induction of sister chromatid exchanges. | the mutagenicity of various alkylating sugar alcohol derivatives in the salmonella-microsome assay was studied, and the effects of these compounds on the colony-forming ability and the frequency of sister chromatid exchange (sce) in chinese hamster cells were determined. cytostatic drugs under clinical trial [elobromol (dbd), myelobromol (dbm), lycurim (ly), zitostop (zi)], others in preclinical analysis [dianhydrogalactitol (dag), 3,4-diacetyldianhydrogalactitol (diacdag), 3,4-disuccinyldianhyd ... | 1983 | 6349793 |
| bovine bladder urothelial cell activation of carcinogens to metabolites mutagenic to chinese hamster v79 cells and salmonella typhimurium. | the ability of bovine bladder urothelial cells to activate genotoxic chemicals to mutagens was examined by cocultivating bladder cells with chinese hamster v79 cells or salmonella typhimurium as mutable targets. activation of test chemicals to mutagenic intermediates by urothelial cells was detected by induction of 6-thioguanine resistance in v79 cells or by induction of histidine revertants in salmonella. in the bladder cell-mediated v79 cell mutagenesis system, a significant increase in mutati ... | 1983 | 6352016 |
| tumorigenicity in vivo and induction of mutagenesis and dna repair in vitro by aclacinomycin a and marcellomycin: structure-activity relationship and predictive value of short-term tests. | the genotoxicity of two new anthracycline antitumor antibiotics, aclacinomycin a and marcellomycin, which are potent cytostatic agents similar to adriamycin and daunomycin, was investigated in various assays. in contrast to adriamycin and daunomycin, both agents were devoid of mutagenic activity in the salmonella-microsome assay as well as in a mammalian cell assay using v79 chinese hamster cells. in primary rat hepatocytes, aclacinomycin a was active in inducing unscheduled dna synthesis, where ... | 1983 | 6352017 |
| 1-nitropyrene reduction by salmonella typhimurium, v79 chinese hamster and primary rat liver cells. | 1983 | 6353221 | |
| gene mapping and linkage analysis in chinese hamster: assignment of the genes for aprt, ldha, idh2, and gaa to chromosome 3. | interspecific somatic cell hybrids were generated by fusion of chinese hamster spleen cells or primary fibroblasts with cells from an adenine phosphoribosyltransferase (aprt)-deficient mouse subline derived from lmtk- cl.1d. subclones which had been selected for either retention or loss of aprt were subjected to combined isozyme and chromosome segregation analysis. concordant expression or segregation of chinese hamster aprt, lactate dehydrogenase a (ldha), isocitrate dehydrogenase 2 (idh2), and ... | 1983 | 6353627 |
| drug resistance in chinese hamster lung and mouse tumor cells. | studies of chinese hamster and mouse cells with high levels of acquired resistance to dactinomycin, daunorubicin, or vincristine have shown that these different permeability mutants all display similar phenotypic alterations: dramatic changes toward normal cell morphology and growth behavior and substantially reduced oncogenic potential. all three resistant cell types show increased expression of a high molecular weight plasma membrane glycoprotein species, gp150. uniquely, vincristine-resistant ... | 1983 | 6354433 |
| ciglitazone, a new hypoglycemic agent. i. studies in ob/ob and db/db mice, diabetic chinese hamsters, and normal and streptozotocin-diabetic rats. | ciglitazone, 5-[4-(1-methylcyclohexylmethoxy) benzyl]-thiazolidine-2,4-dione, is a new hypoglycemic agent orally active in the obese-hyperglycemic animal models. in c57bl/6j-ob/ob mice, treatment with 100 mg/kg ciglitazone for 2 days elicited a drastic fall in blood glucose. it also decreased plasma insulin, triglycerides, and free fatty acids and food intake without affecting the body weight. its hypoglycemic activity was independent of its effect on food intake. regranulation of islet beta-cel ... | 1983 | 6354790 |
| association between the mammalian 110,000-dalton heat-shock protein and nucleoli. | a rabbit antiserum has been prepared using as antigen the 110,000-dalton mammalian heat-shock protein. this protein was purified for injection by two-dimensional page of heat-shocked chinese hamster ovary cells. characterization by immunoautoradiography and immunoprecipitation reveals that the antiserum is specific for the 110,000-dalton protein. both techniques also reveal that the protein against which the antiserum is directed is induced by heat shock. indirect immunofluorescence shows that t ... | 1983 | 6355118 |
| immunocytochemical localization of cytoskeletal proteins and histone 2b in isolated membrane-depleted nuclei, metaphase chromatin, and whole chinese hamster ovary cells. | immunocytochemical techniques employing protein a-gold labeling were used to locate actin, tubulin, and histone 2b in thin sections of embedded, isolated membrane-depleted nuclei, metaphase chromosomes, and whole chinese hamster ovary (cho) cells. actin and tubulin were detected in significant amounts in the cytoplasm and the nucleus of whole cells. the isolated membrane-depleted nuclei and metaphase chromosomes showed levels of actin and tubulin labeling either comparable to or sometimes lower ... | 1983 | 6355287 |
| mutagenicity and cytotoxicity of five antitumor ellipticines in mammalian cells and their structure-activity relationships in salmonella. | the mutagenicity and cytotoxicity of five antitumor compounds (ellipticines) were investigated in the chinese hamster ovary cell hypoxanthine-guanine phosphoribosyltransferase assay and in six strains of salmonella. all five compounds (ellipticine, 9-methoxyellipticine, 9-hydroxyellipticine, 9-aminoellipticine, and 2-methyl-9-hydroxyellipticinium) were cytotoxic and mutagenic in the chinese hamster ovary cell hypoxanthine-guanine phosphoribosyltransferase assay in the presence or absence of aroc ... | 1983 | 6344986 |
| localization of s-100 protein in müller cells of the retina--1. light microscopical immunocytochemistry. | s-100 is an acidic brain protein previously found to be present in glial cells of the brain and the nervous system of gut and respiratory tract. immunocytochemistry at the light microscopical level localized immunoreactivity for s-100 in the müller cells in the retina of rat, guinea pig, and chinese hamster. the müller cells represent the main glial component of the retina, with a structural role in the support and insulation of neurons and sensory elements. the use of s-100 protein as an immuno ... | 1983 | 6345449 |
| efficient procedure for transferring specific human genes into chinese hamster cell mutants: interspecific transfer of the human genes encoding leucyl- and asparaginyl-trna synthetases. | we have developed a simple and efficient procedure for transferring specific human genes into mutant chinese hamster ovary cell recipients that does not rely on using calcium phosphate-precipitated high-molecular-weight dna. interspecific cell hybrids between human leukocytes and temperature-sensitive chinese hamster cell mutants with either a thermolabile leucyl-trna synthetase or a thermolabile asparaginyl-trna synthetase were used as the starting material in these experiments. these hybrids c ... | 1983 | 6346061 |
| cellular oxygen utilization and radiation response of v-79 spheroids. | chinese hamster v-79-171 cells, when placed in stirred suspension cultures, spontaneously grow as spherical multicell aggregates (spheroids) which eventually contain many thousand tightly-packed cells. these spheroids thus provide a valuable model for the study of oxygen transport, since oxygen concentration at the spheroid periphery can be fairly precisely controlled in the stirred suspension, and the consequences of oxygen diffusion inward through the tissue-like mass can be determined experim ... | 1983 | 6356808 |
| mutagenicity studies on herring gulls from different locations on the great lakes. ii. mutagenic evaluation of extracts of herring-gull eggs in a battery of in vitro mammalian and microbial tests. | herring-gull (larus argentatus) eggs were collected from five locations on the great lakes and from one colony on the atlantic coast for organochlorine analysis and mutagenesis testing. the great lakes colonies were chosen for their different contaminant levels, while the atlantic coast colony was used as a relatively clean control. the eggs were homogenized and extracted, and the extracts were tested in the salmonella/mammalian microsome assay for induction of point mutations and in chinese ham ... | 1983 | 6361273 |
| cytotonic enterotoxins and cytotoxic factors produced by salmonella enteritidis and salmonella typhimurium. | strains of salmonella enteritidis and salmonella typhimurium isolated from human diarrheal cases produced heat-labile enterotoxin(s) and cytotoxic factor(s) which elongated, lysed or deformed chinese hamster ovary cells in tissue culture. the toxin(s) caused fluid accumulation in ligated rabbit gut loops and produced increased skin permeability. salmonella toxin produced by these strains does not cross-react immunologically with high titer vibrio cholerae toxin antisera or heat-labile escherichi ... | 1983 | 6362074 |
| c-sis is translocated from chromosome 22 to chromosome 9 in chronic myelocytic leukemia. | by analysis of a series of somatic cell hybrids derived by fusion of either mouse or chinese hamster cells with leukocytes from different chronic myelocytic leukemia (cml) patients or from normal donors, we have localized the human oncogene, c-sis, on the q11 to qter segment of chromosome 22 and demonstrated its translocation from chromosome 22 to chromosome 9 (q34) in cml. | 1983 | 6306134 |
| regulation of phosphatidylcholine biosynthesis in mammalian cells. i. effects of phospholipase c treatment on phosphatidylcholine metabolism in chinese hamster ovary cells and lm mouse fibroblasts. | addition of phospholipase c from clostridium perfringens to cultures of chinese hamster ovary (cho) cells resulted in rapid degradation of cellular phosphatidylcholine with concomitant release of phosphocholine. the rate of incorporation of radiolabeled choline into lipids was increased 2-fold in phospholipase c-treated cho cells as compared to untreated controls. the only enzyme in the pathway of phosphatidylcholine biosynthesis with increased activity in phospholipase c-treated cells was ctp:p ... | 1983 | 6296084 |
| regulation of phosphatidylcholine biosynthesis in mammalian cells. ii. effects of phospholipase c treatment on the activity and subcellular distribution of ctp:phosphocholine cytidylyltransferase in chinese hamster ovary and lm cell lines. | ctp:phosphocholine cytidylyltransferase was located in both the cytosolic and particulate fractions from chinese hamster ovary cells. the activity of the cytosolic form of the enzyme was greatly enhanced by incubation with sonicated preparations of several different lipids, although incubations with either phosphatidylcholine or 1,2-sn-diolein did not increase activity. the activation of the cytidylyltransferase in chinese hamster ovary cells treated with phospholipase c from clostridium perfrin ... | 1983 | 6296085 |
| identification of a cellular receptor for mouse mammary tumor virus and mapping of its gene to chromosome 16. | pseudotypes of vesicular stomatitis virus (vsv) containing envelope glycoproteins provided by c3h mammary tumor virus (mtv) instead of the normal vsv g-proteins were prepared and used to assay the presence of an mtv receptor on cells. the assay was specific as demonstrated by competition studies with excess mtv particles and neutralization of the pseudotypes with anti-mtv serum or monoclonal antibodies directed against mtv gp52. the mtv receptor was abundantly present on mouse cells but hardly d ... | 1983 | 6296428 |
| characterization of the soluble glycoprotein released from vesicular stomatitis virus-infected cells. | vesicular stomatitis virus-infected chinese hamster ovary cells release into the extracellular medium a soluble form of the vesicular stomatitis virus glycoprotein (g protein) termed gs (kang and prevec, virology 46:678-680, 1971). the properties of this molecule and the cellular site at which it is generated were characterized. by comparing the sizes and the peptide maps of the unglycosylated forms of g and gs, we found that between 5,000 and 6,000 daltons of the carboxy-terminal end of the g p ... | 1983 | 6296461 |
| chromosomal assignment of the gene for the human beta 2-adrenergic receptor. | chinese hamster fibroblasts (chw) fail to physiologically respond to the beta-adrenergic agonist isoproterenol with an increase in cellular camp. this unresponsiveness is due to a lack of beta-adrenergic receptors as indicated by an absence of specific binding of 125i-labeled hydroxybenzylpindolol (125i-hyp) to chw plasma membranes. preparation of somatic cell hybrids between chw and human peripheral blood leukocytes led to the selection of a panel of 15 human-chinese hamster cell hybrid clones, ... | 1983 | 6296869 |
| discriminatory inhibition of protein synthesis in cell-free systems by vaccinia virus transcripts. | the effect of vaccinia virus early transcripts on cellular (globin, hela, chinese hamster ovary) and viral (vaccinia, encephalomyocarditis) mrna function was studied in reticulocyte and wheat germ cell-free protein-synthesizing systems. vaccinia virus transcripts of two size classes (8-10 s and 4-7 s), generated in vitro by viral cores, inhibited function of cellular and encephalomyocarditis virus mrna but not that of vaccinia virus in reticulocyte lysate systems. mild alkaline hydrolysis or mic ... | 1983 | 6296875 |
| mutagenesis in chinese hamster cells by cyclopenta(a)phenanthrenes activated by a human hepatoma cell line. | the cyclopenta(a)phenanthrene, 15,16-dihydro-11-methyl-cyclopenta(a)phenanthren-17-one, had potent mutagenic activity in cell-mediated mutation assays with v79 chinese hamster cells as targets, and cells of the human hepatoma line hepg2 as mediators of activation. the compound was inactive when low-passage hamster embryo cells were used as activators. when the mutagenic activity of a series of cyclopenta(a)phenanthrenes was compared in mutation assays with hepg2 cells as activators, there was a ... | 1983 | 6297728 |
| human and rodent transformed cells are more sensitive to in vitro induction of sce by n-methyl-n'-nitro-n-nitrosoguanidine (mnng) than normal cells. | the sensitivity to sister chromatid exchange (sce) induction by n-methyl-nitro-n'-nitrosoguanidine (mnng) in human, mouse, chinese hamster, and syrian hamster normal cell strains and in permanent transformed cell lines of the same species was compared. exponentially growing or growth-inhibited cultures of permanent cell lines transformed spontaneously or by chemical carcinogen or oncogenic virus responded with a higher sce frequency after mnng treatment than did normal diploid cell strains. comp ... | 1983 | 6299927 |
| organization of a chinese hamster ovary dihydrofolate reductase gene identified by phenotypic rescue. | we have constructed a genomic dna library from a methotrexate-resistant chinese hamster ovary cell line (choc 400) in the cosmid vector phc79. by utilizing a murine dihydrofolate reductase (dhfr) cdna clone, we have identified 66 dhfr+ clones among the 11,000 colonies screened by colony hybridization. to isolate a recombinant cosmid containing the entire dhfr gene, we have tested these colonies for their ability to rescue a dhfr- chinese hamster ovary cell line, using the spheroplast fusion meth ... | 1983 | 6310370 |
| amphotericin b selection of mutant chinese hamster cells with defects in the receptor-mediated endocytosis of low density lipoprotein and cholesterol biosynthesis. | this paper describes a rapid and efficient two-step procedure for the isolation of mutant cells with defects in receptor-mediated endocytosis. the procedure takes advantage of two fungal metabolites, compactin (ml236b), a potent inhibitor of cholesterol biosynthesis, and amphotericin b, a polyene antibiotic that forms toxic complexes with sterols in membranes. mutagen-treated chinese hamster ovary cells were preincubated overnight in a medium containing mevalonate, low density lipoprotein (ldl), ... | 1983 | 6310583 |
| high-frequency structural gene deletion as the basis for functional hemizygosity of the adenine phosphoribosyltransferase locus in chinese hamster ovary cells. | the cho-at3-2 chinese hamster ovary cell line is functionally hemizygous for the adenine phosphoribosyltransferase (aprt; ec 2.4.2.7) locus. class 1 aprt +/- heterozygotes, such as cho-at3-2, can be isolated at high spontaneous frequencies from wild-type cho cell populations. simon et al. [simon, a. e., taylor, m. w., bradley, w. e. c. & thompson, l. (1982) mol. cell. biol. 2, 1126-1133] have proposed that a high-frequency event that inactivates one aprt allele might be responsible for both the ... | 1983 | 6310607 |
| genetic evidence that action of camp-dependent protein kinase is not an obligatory step for antiviral and antiproliferative effects of human interferon in chinese hamster ovary cells. | several chinese hamster ovary (cho) cell mutants with altered camp-dependent protein kinases were utilized to study the possible involvement of this enzyme in mediating interferon effects in cultured cells. human fibroblast interferon had a pronounced protective effect for cho cells against encephalomyocarditis virus (emcv). this protective effect was also observed in camp-resistant cho mutants with protein kinase defects, although to a slightly lesser extent. emcv, however, which grows well in ... | 1983 | 6310882 |
| tn5-induced mutations affecting virulence factors of bordetella pertussis. | transposon tn5 was used to isolate mutants of bordetella pertussis. strains with tn5 insertions were screened for loss of virulence-associated factors, including filamentous hemagglutinin, hemolysin, and pertussis toxin. several mutants deficient for hemolysin production were obtained. all produced dermonecrotic toxin, pertussis toxin, and filamentous hemagglutinin, but were found to vary with respect to adenylate cyclase production. one hemolysin mutant had no detectable adenylate cyclase activ ... | 1983 | 6311749 |
| modification of the in vitro activities of amosite asbestos by surface derivatization. | the in vitro cytotoxicity of amosite asbestos and its silanized and bovine serum albumin conjugated derivatives were studied in two cell lines. the overall cytotoxicity of amosite towards chinese hamster lung cells (v79-4) was not affected by derivatization, although the rate of cell-particle interaction was reduced. protein derivatization virtually abolished the cytolytic action of amosite to the macrophage-like cell line (p388d1), although this derivatized material still induced the release of ... | 1983 | 6312061 |
| an intestinal cell-mediated chromosome aberration test for the detection of genotoxic agents. | the use of rat-liver s9 in genotoxicity tests may not reflect true metabolism by whole cells, particularly cells of target organs. we have tested mucosal cells of the mouse small intestine for the capacity to mediate activation/inactivation of chemical carcinogens. mucosal cells were isolated by pronase digestion. three million cells were co-cultured with chinese hamster ovary fibroblasts during a 3-h exposure to chemical clastogens. in the presence of the mucosal cells, aflatoxin b1 (100 microm ... | 1983 | 6314130 |
| rabbit alveolar macrophage-mediated mutagenesis of polycyclic aromatic hydrocarbons in v79 chinese hamster cells. | rabbit pulmonary alveolar macrophages (pam) were used as a metabolizing device in combination with v79 chinese hamster cells as a mutational indicator system. the capacity for metabolic activation of benzo[a]pyrene (b[a]p), its 7,8-diol and 2-aminoanthracene by pam was investigated. because of the high variation between different pam preparations, a statistically significant effect of the 3 compounds could only be demonstrated in a series of 4 or 5 experiments. when the ability of pam to metabol ... | 1983 | 6314131 |
| cell specific activation of benzo[a]pyrene by fibroblasts and hepatocytes. | the cell specific activation of benzo[a]pyrene (bp) by embryonic fibroblasts and by mature hepatocytes to intermediates that can interact with dna, or cause mutations in chinese hamster v79 cells has been investigated. at bp concentrations of up to 15 mum, bp was activated to mutagenic intermediates for the v79 cells by embryonic fibroblasts but not by hepatocytes. however, hepatocytes from rats that had been pretreated with an inducer of the mixed function oxidases, 3-methylcholanthrene, did me ... | 1983 | 6315253 |
| localization of a gene controlling the expression of the human transferrin receptor to the region q12 leads to qter of chromosome 3. | a monoclonal antiserum, 66-ig10, raised against human thymocytes was found to be directed against the human transferrin receptor. a panel of human x chinese hamster somatic cell hybrids, in conjunction with the 66-ig10 reagent, was used to assign the gene(s) coding for the transferrin receptor to the q12 leads to qter region of human chromosome 3. | 1983 | 6315310 |
| in vitro effects of mineral fibers. | in vivo tests available to determine the toxicity of mineral fibers are too expensive and time-consuming to be regularly employed in the evaluation of the potential health hazard posed by natural and man-made fibers. in vitro procedures, while economical, convenient and capable of ranking "relative toxicity," are uncertain predictors of specific lesions. thus, it is of interest to compare the results of various standard in vitro tests with the results of in vivo tests. data are available for int ... | 1983 | 6315352 |
| correlation of in vitro and in vivo methods by means of mass dose and fiber distribution for amosite and fibrous ferroactinolite. | oncogenesis and in vitro data (reported elsewhere in detail) are compared on the basis of relative activity by mass and by dimensional fiber parameters. when tumor induction is compared to the number of fibers of various lengths and aspect ratios in the dose in rats to the degree of tumor induction, a degree of difference with the long thin fiber concept of tumorigenesis by mineral fibers is noted. consistency is re-established, however, when cognizance is taken of the change in the length and a ... | 1983 | 6315381 |
| inhibition of initiator-induced sv40 gene amplification in sv40-transformed chinese hamster cells by infection with a defective parvovirus. | amplification of sv40 genes in sv40-transformed chinese hamster embryo cells (co631) by chemical carcinogens as well as by herpes simplex virus infection can be inhibited by infection with the defective parvovirus, aav-5. this is shown by in situ hybridization with sv40 dna of aav-5-infected co631 cells after treatment with herpes simplex virus type 1 or with chemical carcinogens: the initiator-induced selective amplification of sv40 sequences is prevented in the presence of the parvovirus. duri ... | 1983 | 6315605 |
| immunoelectron microscopic studies of the intracellular transport of the membrane glycoprotein (g) of vesicular stomatitis virus in infected chinese hamster ovary cells. | an immunoelectron microscopic study was undertaken to survey the intracellular pathway taken by the integral membrane protein (g-protein) of vesicular stomatitis virus from its site of synthesis in the rough endoplasmic reticulum to the plasma membrane of virus-infected chinese hamster ovary cells. intracellular transport of the g-protein was synchronized by using a temperature-sensitive mutant of the virus (0-45). at the nonpermissive temperature (39.8 degrees c), the g-protein is synthesized i ... | 1983 | 6315743 |
| identification of a new protein present in vesicular stomatitis virus-infected chinese hamster ovary cells as a degradation product of viral m protein. | in addition to the five previously described vesicular stomatitis virus (vsv) proteins (l, g, n, ns, and m), a protein (mr 17,500) accumulated late in infection of chinese hamster ovary cells. the protein, designated m', was a cleavage product of the viral m protein (mr 26,000) both in vivo and in vitro. (a) m' was precipitated by anti vsv serum, indicating that it is of viral origin. (b) m' peptides generated using staphylococcus v8 protease or chymotrypsin were shared by m, but not by the othe ... | 1983 | 6316634 |
| [expression of malignancy traits in the interspecific somatic hybrids of tumor and normal cells]. | tumorigenicity and anchorage independence in two types of the interspecies hybrids of the tumor and normal mammalian cells were studied. one hybrid type was derived from fusion of spontaneously transformed chinese hamster and normal mouse cells; the second type was obtained by fusion of sv40-transformed djungarian hamster and the same mouse cells. the tumorigenicity in the athymic nude mice was suppressed in the first type of hybrids. the hybrid clones derived from fusion of sv40-transformed and ... | 1983 | 6317520 |
| influence of inhibitors of poly(adp-ribose) polymerase on dna repair, chromosomal alterations, and mutations. | the influence of inhibitors of poly(adp-ribose) polymerase such as 3-aminobenzamide (3ab) and benzamide (b) on the spontaneously occurring as well as mutagen induced chromosomal aberrations, sister chromatid exchanges (sces) and point mutations has been studied. in addition, we have measured the influence of 3ab on dna repair following treatment with physical and chemical mutagens. post treatment of x-irradiated mammalian cells with 3ab increases the frequencies of induced chromosomal aberration ... | 1983 | 6317638 |
| biosynthesis of n- and o-linked oligosaccharides of the low density lipoprotein receptor. | in human fibroblasts, the receptor for low density lipoprotein (ldl) is synthesized as a precursor of apparent mr = 120,000 which is converted to a mature form of apparent mr = 160,000, as determined by migration in sodium dodecyl sulfate (sds)-polyacrylamide gels (tolleshaug, h., goldstein, j. l., schneider, w. j., and brown, m. s. (1982) cell 30, 715-724). the current paper describes the relationship of n- and o-glycosylation to this post-translational modification. oligosaccharides were analy ... | 1983 | 6317691 |
| assignment of murine cellular harvey ras gene to chromosome 7. | mouse-chinese hamster somatic cell hybrids containing various combinations of mouse chromosomes were analyzed for the presence of the mouse c-ha-ras (1) sequences after restriction endonuclease digestion and hybridization with a 32p-labeled ha-ras specific probe according to the procedure of southern (2). the presence of the mouse c-ha-ras containing fragment was correlated with the presence of mouse chromosome 7 in the hybrids. | 1983 | 6318374 |
| metabolism and macromolecular covalent binding of benzo[a]pyrene in cultured fischer-344 rat lung type ii epithelial cells. | pulmonary biotransformation of many xenobiotics may be important for the mutagenic, carcinogenic and/or toxic response of lung tissue to these compounds. recently, a lung epithelial cell line (designated lec), with morphological characteristics suggestive of type ii cell origin, was developed in our laboratory. when lec cells were co-cultivated with chinese hamster ovary (cho) cells in a cell-mediated mutagenesis assay, lec metabolized promutagens to metabolites mutagenic to the cho cells [a. p. ... | 1983 | 6318771 |
| monoclonal antibody against microtubule associated protein-1 produces immunofluorescent spots in the nucleus and centrosome of cultured mammalian cells. | a monoclonal antibody was raised against the highest molecular weight protein associated with microtubules (map-1). its specific binding to map-1 was determined by immunoblotting of the gel electrophoretogram of microtubule proteins prepared from porcine brain. the antibody reacted only with map-1, not with map-2, tau or tubulin. indirect immunofluorescent staining by this antibody showed bright intranuclear spots, the centrosome and the faint meshwork of the cytoplasm in several types of cultur ... | 1983 | 6368013 |
| evaluation of the mutagenic potential of the hair dye n-methyl-amino-2-nitro-4-n',n'-bis-(2-hydroxyethyl)-aminobenzene in a battery consisting of drosophila and mammalian cytogenetic assays. | the compound n-methyl-amino-2-nitro-4-n', n'-bis(2-hydroxyethyl)-aminobenzene was tested for mutagenic activity in the sex-linked recessive lethal test with drosophila melanogaster, the induction of chromosomal aberrations and sister-chromatid exchanges (sces) with chinese hamster ovary (cho) cells in vitro, and the micronucleus test with mouse bone-marrow cells in vivo. consistently negative results were obtained with the 3 tests. the sce tests gave positive results with prolonged treatments. i ... | 1983 | 6402694 |
| genetic toxicology of ethylenediaminetetraacetic acid (edta). | edta and its salts have a number of applications in medicine and pharmacy. edta is used to remove calcium from the human body, and serves as an anticoagulant and as a detoxicant after poisoning by heavy metals. it is often used in analytical chemistry for complexometric titrations and many other purposes. because the compound is of rather low toxicity, it is used as a food additive to bind metal ions. edta affects the inhibition of dna synthesis in primary cultures of mammalian cells. this may b ... | 1983 | 6406880 |
| identification of a structural gene for a rna polymerase ii polypeptide in drosophila melanogaster and mammalian species. | using subclones representing 14 kilobase pairs (kb) of dna from the drosophila melanogaster rna polymerase ii (ec 2.7.7.6) x-linked genetic locus, rpii, we have identified four poly(a)+ rna transcripts in adult flies. the dna encoding only one of these, a 7-kb transcript, cross-hybridized to mammalian dna. dna from alpha-amanitin-resistant (amar) chinese hamster ovary (cho) and human cells was used to transform the temperature-sensitive (ts) rna polymerase ii syrian hamster mutant tsaf8. the acq ... | 1983 | 6407013 |
| genotoxicity of brown-colored polymerization products formed in smoke flavors. | smoke aroma essences, which are prepared from smokehouse smoke by condensation and purification, are used for flavoring raw food products. the essences spontaneous decompose and produce brown-colored polymerization products, which may react with protein and be liberated within the acidic environment of the human stomach. the potential of these products to cause dna damage was studied in two microbial and two in vivo assay systems. the polymerization products induced his+ reversion in salmonella ... | 1983 | 6356042 |
| cytotoxicity and sister chromatid exchanges induced in vitro by six anticancer drugs developed in the people's republic of china. | growth inhibition in the chinese hamster cell line v79 and in the human lymphoid cell line raji and induction of sister chromatid exchange(s) (sce) in v79 cells after treatment with six anticancer drugs [harringtonine (hrt), homoharringtonine (hhrt), camptothecin (cpt), hydroxycamptothecin (hcpt), lycobetaine (lbt), and oxalysine (oxl)] developed in the people's republic of china were studied. oxl is a new antibiotic; all other drugs are plant extracts. all drugs caused a dose-dependent growth i ... | 1983 | 6413744 |
| mutagenicity of rubber additives and curing fumes. results from five short-term bioassays. | the mutagenicity of rubber additives and curing fumes from some rubber formulations were studied in five short-term tests: point mutations in chinese hamster v79 cells, the induction of sister chromatid exchanges in chinese hamster ovary cells, micronuclei in erythrocytes of chinese hamster bone marrow, sex-linked recessive lethal mutations in drosophila melanogaster, and reverse mutations in the salmonella/microsome assay. when 46 rubber additives were tested with salmonella, 15 compounds were ... | 1983 | 6415811 |
| mutagenicity evaluation of glutaraldehyde in a battery of in vitro bacterial and mammalian test systems. | glutaraldehyde was evaluated for genotoxicity using a battery of four in vitro test systems: the salmonella/microsome assay, the chinese hamster ovary cell/hypoxanthine-guanine phosphoribosyltransferase (cho/hgprt) gene mutation system, the sister-chromatid exchange test with chinese hamster ovary cells, and measurements of unscheduled dna synthesis in primary rat-hepatocyte cultures. no significant, dose-related increases in the various end-points were produced by glutaraldehyde in tests with o ... | 1983 | 6418627 |
| is pulsed ultrasound mutagenic? | the possibility that microsecond pulses of 3 mhz ultrasound may interact at the cellular level, with genetic consequences, was investigated using two different endpoints. the ames mammalian microsome test was employed to assess mutagenicity and viability in salmonella typhimurium bacteria, while the sister chromatid exchange frequency provided an indicator of ultrasound induced effects at the chromosome level in chinese hamster ovary cells. | 1983 | 6400263 |
| investigation into the possible genetic effects of diagnostic ultrasound. | the mutagenic effect of dus (diagnostic ultrasound) was examined using two generators emitting continuous waves and pulsed waves, respectively. three different test systems for mutagenic activity were employed in this study. 1. the frequency of sister chromatid exchanges (sces) was determined in metaphase chromosomes of human lymphocytes and of chinese hamster ovary (cho) cells sonicated at different stages of the cell cycle. 2. the induction of dna single strand breaks was tested in cho cells t ... | 1983 | 6400270 |
| molecular identification of a human dna repair gene following dna-mediated gene transfer. | although it has long been evident that the response of eukaryotes to dna damaging agents is determined by the effectiveness of a variety of dna repair systems, there is little detailed knowledge of the nature of these systems or the genes which control them. in humans, a number of hereditary conditions, including xeroderma pigmentosum, ataxia telangiectasia and fanconi's anaemia, exhibit increased sensitivity to a variety of dna damaging agents and a predisposition to cancer, suggesting a defect ... | 1983 | 6417541 |
| mutation of chinese hamster v79 cells and transformation and mutation of mouse fibroblast c3h/10t1/2 clone 8 cells by aflatoxin b1 and four other furocoumarins isolated from two nigerian medicinal plants. | mutation by aflatoxin b1 (afb1), imperatorin, marmesin, chalepin, and 8-methoxypsoralen (mop), with and without black light (bl; long-wavelength ultraviolet light) activation, was determined at the hypoxanthine-guanine phosphoribosyltransferase locus (8-azaguanine resistance) in chinese hamster v79 cells and at the ouabain locus in mouse c3h/1ot1/2 cells. transformation by these furocoumarins under the same activation conditions was also investigated in c3h/1ot1/2 cells. in v79 cells, afb1 induc ... | 1983 | 6402296 |
| aphidicolin-induced endoreduplication in chinese hamster cells. | aphidicolin, a specific inhibitor of dna polymerase alpha, was found to induce high frequencies of endoreduplication in chinese hamster v79 cells in a dose-dependent manner. the aphidicolin-induced endoreduplication was observed when cells were incubated at 37 degrees but not at 41 degrees. since it is known that dna polymerase beta is more thermally labile than is dna polymerase alpha, the data are consistent with the hypothesis that dna polymerase beta might be responsible for endoreduplicatio ... | 1983 | 6402298 |
| chromosomal assignments of three random rflp loci defined by base-pair changes in mspi sites. | three cloned single copy sequences isolated from a random partial plasmid library of human ecori-hindiii restriction fragments detect mspi site polymorphisms in human dna. since at least two of them have allele frequencies that make them suitable for family linkage studies, we have determined their chromosomal localizations. dna samples extracted from a panel of 31 chinese hamster x human somatic cell hybrids, that were derived from six different human donors, were analyzed for the presence of h ... | 1983 | 6209528 |
| composition and synthesis during g1 and s phase of a high mobility group-e/g component from chinese hamster ovary cells. | a perchloric acid soluble protein from the sedimented chromatin of blended chinese hamster ovary (line cho) cells has been isolated by guanidine hydrochloride gradient chromatography on bio . rex-70 ion exchange resin. the amino acid composition of the protein (designated as cho hmg-e/g) is similar to that of mouse hmg-e, but it differs from that of bovine hmg-14 and hmg-17 or any possible mixture of the two. cho hmg-e/g incorporates [32p]phosphate like hmg-14 and hmg-17 class proteins from othe ... | 1983 | 6218827 |
| unusual neutral oligosaccharides in mature sindbis virus glycoproteins are synthesized from truncated precursor oligosaccharides in chinese hamster ovary cells. | we have previously demonstrated the presence of unusual small asparaginyl-oligosaccharides [(man)3glcnac2-asn] in the mature glycoproteins of sindbis virus released from both wild-type and lectin-resistant chinese hamster ovary cells, but the mechanism of synthesis of these structures was not determined. gel filtration and endo-beta-n-acetylglucosaminidase analyses of pronase-digested glycopeptides from [3h]mannose-labelled sindbis virus released at different times after infection of a phytohaem ... | 1983 | 6298348 |
| characterization of binding and uptake of 3,3',5-triido-l-thyronine in cultured mouse fibroblasts. | the binding and internalization of 3,3'-[125i] 5-triiodo-l-thyronine ([125i]t3) was studied in cultured swiss 3t3-4 mouse fibroblasts. at 0 c, the binding of t3 to cells is saturable, reversible, and stereospecific. these results together with those of earlier fluorescence studies using rhodamine-labeled t3 demonstrate the presence of specific plasma membrane t3 receptors. at 37 c, the uptake of t3 reached a steady state after 1 h, and approximately 57 fmol t3 were specifically taken up by 10(6) ... | 1983 | 6299708 |
| biochemical characterization of the amiloride-sensitive na+/h+ antiport in chinese hamster lung fibroblasts. | net h+ fluxes across the plasma membrane of chinese hamster lung fibroblasts (cc139) were monitored by ph-stat titration. na+-depleted cells release h+ upon addition of na+. conversely na+- or li+-loaded cells take up h+ from the medium when shifted to a na+,li+-free medium. this reversible na+ (or li+)-dependent h+ flux is inhibited by amiloride and does not occur in digitonin-permeabilized cells. a similar na+/h+ exchanger was identified in vascular smooth muscle cells, corneal and aortic endo ... | 1983 | 6300047 |
| cell hybrids between sv40-transformed macrophage cell lines and a chinese hamster cell line: growth responsiveness and induction of colony-stimulating factor. | three cell lines from resident macrophages of balb/c mice and four from activated macrophages of the same strain were isolated by infection with simian virus 40 (sv40). a majority of these cells showed dependency on l cell-conditioned medium (lcm), which is necessary for proliferation of normal macrophages in vitro. somatic cell hybridization was applied in the study of macrophage growth responsiveness. a macrophage cell line (br15) with strict dependency on lcm for growth was fused to a chinese ... | 1983 | 6300147 |
| ultrastructural immunocytochemical localization of the phosphomannosyl receptor in chinese hamster ovary (cho) cells. | using ultrastructural immunocytochemistry and antibodies directed against bovine liver phosphomannosyl (pm) receptor, we have localized the receptor in chinese hamster ovary (cho) cells. the majority of the receptor was found within the cell. only a small fraction of the receptor was found on the surface and most of it was clustered in coated pits. because these cells contain endogenous ligands for the receptor, it was not possible to determine if this clustered state was dependent on occupancy ... | 1983 | 6300218 |
| the chinese hamster cell emetine resistance gene. analysis of cdna and genomic sequences encoding ribosomal protein s14. | we used an intersecting pool strategy to recognize chimeric plasmids containing chinese hamster ribosomal protein cdnas. the screening procedure involved hybridization-selection of messenger rnas, cell-free translation of selected mrnas, and electrophoresis of polypeptide products on one- and two-dimensional polyacrylamide gels. the protocol was designed to recognize ribosomal protein s14 cdnas specifically. of 500 chimeric plasmids screened, two possessed cdnas complementary to s14 mrna and 18 ... | 1983 | 6313690 |
| structure of the dihydrofolate reductase gene in chinese hamster ovary cells. | overlapping recombinant lambda 1059 phages carrying regions of the dhfr locus from the amplified chinese hamster ovary (cho) cell clone mk42 have been isolated. in addition, dhfr cdnas from this cell line have been cloned into plasmid pbr322. restriction analysis of these recombinant molecules has led to a map of the chinese hamster dhfr gene. this gene has a minimum size of 26 kb and contains six exons as defined by hybridization to a combination of mouse and cho cdna probes. the latter probes ... | 1983 | 6300788 |
| isolation and characterization of a major tandem repeat family from the human x chromosome. | we report the identification and characterization of a family of repeated restriction fragments whose molecular organization is apparently specific to the human x chromosome. this fragment, identified as an ethidium bromide-staining 2.0 kilobase (kb) band in bamhi-digested dna from a chinese hamster-human somatic cell hybrid containing a human x chromosome, has been cloned into pbr325 and characterized. the 2.0 kb repeated family has been assigned to the xp11 leads to xq12 region on the x by sou ... | 1983 | 6300789 |
| isozymes of rodent 5'-nucleotidase: evidence for two independent structural loci umph-1 and umph-2. | two distinct isozymes (umph-1 and umph-2) which hydrolyse pyrimidine 5'-nucleotides have been identified in mouse, rat and chinese hamster tissues. one of these, umph-1 appears to be specific for pyrimidine 5'-nucleotides, whereas the other, umph-2 has a broader substrate specificity. umph-1 and umph-2 show differences in their expression in different tissues. the evidence suggests that umph-1 and umph-2 are coded by distinct structural gene loci, umph-1 and umph-2. these isozymes have not been ... | 1983 | 6301357 |
| topographical distribution of a membrane-inserted fluorescent phospholipid analogue during cell fusion. | potential alterations in the transbilayer distribution of lipid molecules during cell-cell fusion were studied, using the fluorescent phospholipid analogue 1-acyl, 2-(n-4-nitrobenzo-2-oxa-1,3-diazole)-aminocaproyl phosphatidylcholine (c6-nbd-pc). the fluophore was inserted into the outer leaflet of the plasma membrane of chinese hamster fibroblasts from an exogenous source and cell-cell fusion was induced either with sendai virus or polyethylene glycol (peg). after fusion, the cells were examine ... | 1983 | 6301868 |
| relationship of simian virus 40 tumor antigens to virus-induced mutagenesis. | we analyzed the mutation frequency to 8-azaguanine (8az) resistance in rat fr3t3 cells acutely infected with simian virus 40 wild type and tsa and early deletion mutants and in a series of temperature-sensitive (n) and temperature-insensitive (a) transformants derived from chinese hamster lung (chl) cells. upon acute infection, the frequency of mutation to 8az resistance was raised at most by two- to eightfold over the spontaneous frequency, and it was independent of the presence of a functional ... | 1983 | 6302474 |
| pattern of methylation of two genes coding for housekeeping functions. | the distribution of sites that can be methylated was analyzed in the chinese hamster adenine phosphoribosyl-transferase (aprt) gene and the patterns of methylation of this gene and the mouse dihydrofolate reductase (dhfr) gene were studied by using cpg restriction enzymes. both genes were found to be unmethylated completely at their 5'-end region and methylated heavily throughout the rest of the gene. because the hamster aprt gene can be inhibited by dna methylation in vivo, the results suggest ... | 1983 | 6302681 |
| metabolism of phenanthridine to phenanthridone by rat lung and liver microsomes after induction with benzo[a]pyrene and aroclor. | the comparative metabolism of phenanthridine (3,4-benzoquinoline) by rat lung and liver microsomes has been investigated. the array of metabolites produced by induced lung and liver are qualitatively similar. phenanthridone has been identified as a phenanthridine metabolite produced by induced rat liver and lung. phenanthridone is directly mutagenic in salmonella tester strain ta-98 while phenanthridine is not. although phenanthridone is more mutagenic than phenanthridine after incubation with r ... | 1983 | 6302951 |