TitleAbstractYear(sorted ascending)
mutagenic effects of allylisothiocyanate in escherichia coli wp 67.a mutagenic effect of allylisothiocyanate (aitc) on e. coli wp 67 (trp uvra pola) was only found in a test with metabolic activation in vitro. mixed function oxidases containing cytochrome p-450 are not responsible for the conversion of aitc to mutagenic products. liver microsomal fractions of rat, mouse, chinese hamster, goat and monkey were used for in vitro metabolic activation. the mutagenic effect of aitc differed in individual animal species according to the protein content in the microsom ...19827037578
isolation and chromosomal localization of unique dna sequences from a human genomic library.recombinant bacteriophage lambda from a human genomic library were screened to indentify human dna inserts having only unique sequences. unique human inserts were found in about 1% of the phage screened. one recombinant phage, p3-2, was studied in detail. it contains a human insert of 14.7 kilobases with four internal ecori cleavage sites. a restriction map was constructed for ecori and bamhi sites. hybridization of the 32p-labeled p3-2 probe to a southern blot of ecori-digested total human dna ...19827038688
stimulation of the hexosemonophosphate-pentose pathway by pyrroline-5-carboxylate in cultured 1-pyrroline-5-carboxylic acid, an intermediate in the interconversions of proline, ornithine, and glutamate, is a potent stimulator of glucose oxidation through the hexosemonophosphate-pentose pathway. the effect is observed in cultured human fibroblasts, chinese hamster ovary cells (cho-k1), and rabbit kidney cells (llc-rk1). in human fibroblasts, the magnitude of the stimulation of the hexosemonophosphate-pentose pathway is dependent on the concentration of added pyrroline-5-carboxylate ...19826896335
interindividual variation of carcinogen activation by human liver homogenates. a study using dimethylnitrosamine (dmn) and cyclophosphamide (cp) as precursor genotoxic agents and clastogenicity and induction of sister chromatid exchanges in chinese hamster v79-e cells as endpoints.9000 g supernatants of liver homogenates from 6 kidney transplant donors were checked in combination with chinese hamster v79-e cells in vitro for their capacity to activate dmn and cp. 9000 g fractions were standardized on protein content. induction of chromatid aberrations (clastogenicity assay) and sister chromatid exchanges (sce assay) served as parameters. dmn activation showed a 1.3-fold inter individual variation and was in the same order of magnitude as that observed with rat liver 9000 ...19827103690
isolation of a human repetitive sequence and its application to regional chromosome mapping.recombinant lambda phage charon 4a with repetitive human dna inserts have been constructed by using cellular dna from a human-chinese hamster ovary cell hybrid retaining the complete hamster genome and a single human chromosome 12. one recombinant phage, 12-11, contains several repetitive sequences, each with a different repetition pattern in the human genome. a 2.2-kilobase (kb) ecori fragment of this phage was subcloned in pbr325. this sequence has fewer than 5,000 copies in the human genome a ...19826961418
diverse origins of multiple ovarian teratomas in a single individual.centromere heteromorphisms and enzyme markers were examined in cells cultured from seven benign ovarian teratomas arising in a single patient. three of the teratomas were homozygous for all eight enzyme and centromere markers found to be heterozygous in the host. the other four tumors were heterozygous at the centromeres of chromosomes 1, 16, 17, and 18, as in the patient, but were homozygous for at least one of the enzyme markers. the linkage phases of the heterozygous enzyme markers phosphoglu ...19826961419
the acrosomal zonule.a structure associated with the developing acrosome during spermiogenesis in the rat and the chinese hamster is described. the acrosomal zonule first appears in the cap phase of spermiogenesis and can be detected at all stages of development until after spermiation. the role of the acrosomal zonule is discussed.19827112534
radiation equivalence of genotoxic chemicals. validation in cultured mammalian cell lines.published data on mutations induced by ionizing radiation and 6 monofunctional alkylating agents, namely ems, mms, enng, mnng, enu and mnu, in different cell lines (chinese hamster ovary, chinese hamster lung v79, mouse lymphoma l5178 and human cells) were analysed so that radiation-equivalent chemical (rec) values could be calculated. rec values thus obtained for a given alkylating agent with different cell lines fall within a narrow range suggesting its validation in cultured mammalian cell sy ...19827099190
surface reduction of amorphous nis particles potentiates their phagocytosis and subsequent induction of morphological transformation in syrian hamster embryo cells.the incidence of morphological transformation following exposure of syrian hamster embryo (she) cells to crystalline alphanis particles was considerably greater than that following a similar exposure to amorphous nis particles. these differences in potency were attributable to the selective phagocytosis of crystalline alphanis particles into cells, since untreated amorphous nis particles were not readily taken up. chemical reduction of the amorphous nis particles' surface with lialh4 resulted in ...19827059961
investigation of styrene in the liver perfusion/cell culture system. no indication of styrene-7,8-oxide as the principal mutagenic metabolite produced by the intact rat liver.mutagenic effect of styrene and styrene-7,8-oxide was studied with the isolated perfused rat liver as metabolizing system and chinese hamster v79 cells as genetic target cells. styrene-7,8-oxide which is mutagenic per se was rapidly metabolized by the perfused rat liver. thus no mutagenic effect was detected neither in the perfusion medium nor in the bile. however when styrene was added to the perfusion system, an increase in v79 mutants was observed regardless of where in the circulating perfus ...19827060221
cell-mediated mutagenicity in chinese hamster v79 cells of dibenzopyrenes and their bay-region fluorine-substituted derivatives.the polycyclic aromatic hydrocarbons dibenzo(a,i)pyrene and dibenzo(a,h)pyrene, each of which possesses two bay regions, and their bay-region difluorinated derivatives were tested for mutagenicity for ouabain and 6-thioguanine resistance in chinese hamster v79 cells. since v79 cells do not metabolize polycyclic aromatic hydrocarbons, mutagenesis was tested in both the presence and the absence of golden hamster embryo cells capable of metabolizing polycyclic aromatic hydrocarbons. neither of the ...19827066888
mutagenic responses of five independent genetic loci in cho cells to a variety of mutagens. development and characteristics of a mutagen screening system based on selection for multiple drug-resistant markers.with the aim of developing a sensitive mutagen screening system, the responses of 15 different chemical mutagens at 5 independent genetic loci in chinese hamster ovary (cho) cells have been determined. the genetic markers which have been employed include resistance to thioguanine (thgr), ouabain (ouar), the protein synthesis inhibitor emetine (emtr), the polyamine synthesis inhibitor methylglyoxal bisguanylhydrazone (mbgr) and the nucleoside analog 5,6-dichlororibofuranosyl benzimidazole (drbr). ...19827110183
chromosome-damaging activity of saliva of betel nut and tobacco chewers.saliva of volunteers chewing betel quid, cured betel nut (areca catechu), betel leaves (piper betle), a mixture of quid ingredients (dried betel nut flakes, catechu, cardamon, lime, copra and menthol) and indian tobacco was collected and examined for its genotoxic activity. chromosome aberrations (chromatid breaks and chromatid exchanges) in chinese hamster ovary (cho) cells were used to estimate the genotoxic effect. no detectable levels of clastogenic activity were observed in the saliva of no ...19827116324
clastogenic activity of bile acids and organic acid fractions of human feces.chloroform extracts of fecal material from 4 subjects on normal mixed western diets were fractionated to obtain an acid fraction and a hexane extract containing neutrals and bases. the acid fraction from at least 2 of the donors induced an elevated frequency of chromosomal aberrations and exchanges in chinese hamster ovary (cho) cells. since acid steroids are expected to be present in the acid fraction, 5 bile acids were assayed for clastogenic activity in cho cells. ursodeoxycholic acid induced ...19827116334
cell-mediated mutagenesis and tumor-initiating activity of the ubiquitous polycyclic hydrocarbon, cyclopenta[c,d]pyrene.the ubiquitous polycyclic aromatic hydrocarbon (pah), cyclopenta[c,d]pyrene (cpp), was tested to determine its mutagenicity for 6-thioguanine and ouabain resistance in chinese hamster v79 cells and its tumor-initiating activity in the skin of the tumor susceptible sencar mice. the potent carcinogen/mutagen, benzo[a]pyrene (bp), was included for comparison. inasmuch as v79 cells do not metabolize pahs, mutagenesis was tested both in the presence and in the absence of x-irradiated golden hamster e ...19827116572
phenotypic expression time of mutagen-induced 6-thioguanine resistance in chinese hamster ovary cells (cho/hgprt system): expression in division-arrested cell cultures.the phenotypic expression time of ethyl methanesulfonate (ems) induced 6-thioguanine-resistant mutants was studied with chinese hamster ovary cells in culture (cho/hgprt system). after mutagen treatment of exponential phase cultures, the cells were maintained either in the exponential phase through subculture in medium containing 5% dialyzed fetal bovine serum (fbs) or in a nondividing viable state by use of medium containing 0-1% dialyzed fbs. the time course of expression of the 6-thioguanine- ...19827117212
effect of cocultivation on the levels of spontaneous and induced sister chromatid exchanges in chinese hamster cells.the level of sister chromatid exchanges, both spontaneous and induced by uv light or ethylmethanesulphonate (ems), in chinese hamster v79/ap4 cell line, is partially reduced upon cocultivation with human cells. normal and xeroderma pigmentosum (xp) cells are equally effective. on the basis of these observations, cocultivation may represent a good tool for investigating the sce's formation processes.19827119024
[cytogenetic effects in exposure to high-energy charged particles].the cytogenetic effects of irradiation were investigated in the bone marrow and corneal epithelium of mice, human white blood cells, and stamm v79-4 cells of chinese hamsters exposed to protons with e=9.2 gev, deutons and helium ions with e=4.6 gev/nuclon. it was demonstrated that with an increase in the irradiation dose the number of aberrant cells and chromosome aberrations grew. a high yield of exchange type aberrations was found. the proliferative activity of cells of bone marrow decreased a ...19827120911
cc-1065 (nsc 298223), a most potent antitumor agent: kinetics of inhibition of growth, dna synthesis, and cell (nsc 298223) is the most cytotoxic agent tested against cells in culture in our laboratory. the 50% lethal doses for exponentially growing b16 melanoma and chinese hamster ovary cells were 0.44 and 0.14 ng/ml, respectively, as compared to 35 and 500 ng/ml for adriamycin. in the human tumor-cloning assay, 1-hr exposure to cc-1065 (0.1 ng/ml) caused greater than or equal to 50% lethality in a broad spectrum of tumors. the dose-survival curves for b16 and chinese hamster ovary cells were ch ...19827105029
genetic instability at the adenine phosphoribosyltransferase locus in mouse l cells.resistance to adenine analogs such as 2,6-diaminopurine occurs at a rate of approximately 10(-3) per cell per generation in mouse l cells. this resistance is associated with a loss of detectable adenine phosphoribosyltransferase activity. other genetic loci in l cells have the expected mutation frequency (approximately 10(-6)). transformation of l cell mutants with chinese hamster ovary cell dna results in transformants with adenine phosphoribosyltransferase activity characteristic of chinese ha ...19827110133
effect of split doses of radiation on mutation frequency in rodent cell lines.mutation frequencies in mouse cells and chinese hamster cells were measured following single or split doses of uv light or x-rays. split doses separated by a few to over 24 h induced no more ouabain- or 6-thioguanine-resistant mutants than did comparable single doses. these data lend no support to the possible existence of an inducible error-prone repair system in rodent cells.19827110181
higher efficiency of hamster hepatocytes than rat hepatocytes for detecting dimethylnitrosamine and diethylnitrosamine in hepatocyte-mediated chinese hamster v79 cell mutagenesis assay.the mutagenicities of dimethylnitrosamine (dmn) and diethylnitrosamine (den) on chinese hamster v79 cells were examined by cocultivation of the cells with primary cultures of rat hepatocytes or hamster hepatocytes. mutations in v79 cells were selected by resistance to ouabain. the mutation frequencies induced by all doses of dmn (1, 5, 10 and 50 micrograms/ml) and den (10, 50, 100 and 500 g/ml) were substantially higher on cocultivation with hamster hepatocytes than with rat hepatocytes. thus it ...19827133033
mapping of polypeptide genes by two-dimensional gel electrophoresis of hybrid cell extracts.a series of 18 chinese hamster x human somatic cell hybrid subclones segregating human chromosomes were analyzed by two-dimensional gel electrophoresis to determine the chromosomal location of the human genes responsible for the expression of specific proteins. two independent methods, side by side comparison and double label autoradiography-fluorography, were used to identify the human proteins that were unambiguously resolved from those of the chinese hamster (ch). of the 83 human spots resolv ...19827140373
decreased tumorigenicity of chinese hamster cells after fusion with tumorigenic mouse myeloid leukemia cells. 19827140376
radioresistance secondary to low ph in human glial cells and chinese hamster ovary cells.the influence of the extracellular ph on the radiosensitivity of human glial cells and chinese hamster ovary cells was examined. the period of low ph varied from 0 to 96 hours in glial cells and from 0 to 48 hours in chinese hamster cells. maintenance of low ph after a dose of 10 gy for at least 24 hours for glial cells and at least 6 hours for chinese hamster cells improved survival by more than one order of magnitude at ph 6.4. cellular inactivation by irradiation may be impaired by an extrace ...19827141909
absence of in vitro genotoxicity of pyrvinium pamoate in sister-chromatid exchange, chromosome aberration, and hgprt-locus mutation bioassays.a single preparation of u.s.p. pyrvinium pamoate that exhibited promutagen activity in salmonella/mammalian microsome reverse mutation assays was subjected to in vitro mammalian cell bioassays. cytotoxicity limiting doses of dimethyl sulfoxide-solubilized drug were without effect in the absence and/or presence of liver s9 fraction from aroclor-1254-induced rats in an in vitro chinese hamster ovary (cho) cell assay for chromosome aberration and sister-chromatid exchange induction at concentration ...19827143479
chromosomal localization of the moloney sarcoma virus mouse cellular (c-mos) sequence.the moloney sarcoma virus-specific onc gene, referred to as v-mos, was used as probe to hybridize to restricted dnas from various mouse-chinese hamster hybrid cell lines. these hybrid cells contain, in addition to all of the chinese hamster chromosomes, various numbers (less than a full complement) of mouse chromosomes. comparison of the presence or absence of the mouse cellular mos gene with the known karyotype in each of the hybrid cell lines allows us to conclude that the mos gene is on mouse ...19827143580
clastogenic potential of heavy oil extracts and some aza-arenes in chinese hamster cells in culture.chromosomal aberration tests in vitro, with a chinese hamster fibroblast cell line, chl, were carried out on b class heavy oil fractions, obtained by silica-gel column chromatography and a liquid-liquid extraction method. the original oil and basic nitrogen-containing fractions induced structural chromosomal aberrations in the chl cells in the presence of rat-liver microsome fraction (s9 mix). 8 tricyclic or pentacyclic aza-arenes, which possibly exist in the positive fractions, were also examin ...19827144783
stable integration of adenovirus dna is not required for the induction of mutations in the hypoxanthine phosphoribosyltransferase gene in chinese hamster cells.adenovirus type 2 induces ems-like mutations at the hpt13 locus coding for hypoxanthine phosphoribosyl transferase (hprt) in chinese hamster cells (j. virol., 38, 184--190, 1981). in this report we show that: (a) the hpt- 13 mutation is in the structural gene of hprt, (b) adenovirus induces intracistronic reversion mutations which suppress the hpt- 13 phenotype, and (c) the stable integration of adenovirus dna is not required for the induction of these mutations.19827144795
a comparison of the cytogenetic response to asbestos and glass fibre in chinese hamster and human cell lines. demonstration of growth inhibition in primary human fibroblasts.asbestos and fine glass fibre, which induce high levels of chromosome aberrations and polyploidy in chinese hamster permanent cell lines, were found to cause no increase in chromosome damage or polyploidy in primary human fibroblasts or in human lymphoblastoid lines. in common with permanent cell lines of hamster or human origin, treatment of primary human fibroblasts with higher doses of asbestos or fine glass resulted in almost total growth inhibition, showing that the primary cells are not un ...19827087986
expression time for benzo[a]pyrene-induced 6-thioguanine-resistant mutations in v79 chinese hamster cells.the effect of expression time (the time between the end of the treatment period and the first exposure to selective medium) on the frequency of benzo[a]pyrene (bp)-induced mutations at the hgprt (hypoxanthine-guanine phosphoribosyl transferase locus was examined in the cell-mediated mutation assay in which v79 chinese hamster cells are the targets and bp activation is mediated by syrian hamster embryo cells. after the optimal expression time (4-5 days), the mutation frequency induced by ...19827121490
caffeine-metabolizing capability of primary rat hepatocytes, chinese hamster v79 cells and normal human fibroblasts in culture.caffeine is metabolized by primary rat hepatocytes in culture to metabolites similar to those found in rats in vivo, including 6-amino-5-[n-formylmethylamino]-1,3-dimethyluracil, one of the major caffeine metabolites produced in the rat. at a substrate-limiting level of caffeine, the rat hepatocytes metabolized 25-30% of the total added caffeine in 24 h. about 99% of the metabolites was found in the extracellular medium and rinse fractions, suggesting that on a volume basis, caffeine metabolites ...19827121495
studies of host factors in carcinogenesis using cultured human tissues and cells.recent progress in the development of conditions for culturing epithelial tissues and cells from adult humans has provided cancer researchers with an opportunity to investigate directly the various facets of carcinogenesis in human cells. studies of activation and deactivation of several classes of chemical carcinogens have revealed that the metabolic pathways and the predominant adducts formed with dna are generally similar in humans and experimental animals. wide quantitative interindividual d ...19827152621
structural and functional hemi- and dizygous chinese hamster chromosome 2 gene loci in cho cells.fourteen independent somatic cell hybrid clones made between diphtheria toxin (dt)-resistant mouse cl1d cells and dt-sensitive chinese hamster ovary (cho) cells slowly segregated cho chromosome. concordant segregation analysis of electrophoretically resolvable chinese hamster chromosome 2 gene products and cho chromosomes 2 and z2 (having q1-q24 deletion) in dt-selected and control hybrid subclones was conducted. analysis revealed that loci for dt sensitivity and galactose-1-phosphate uridyltran ...19827123449
isolation of salmonella wien heat-labile enterotoxic activity has been identified in culture filtrates of salmonella wien. the enterotoxin causes fluid accumulation in rabbit ligated ileal loops, firm induration and erythema in rabbit skin and morphological alteration in chinese hamster ovary (cho) cell cultures; it was revealed by treatment with calcium phosphate gel, and purified on deae-sephadex a-50 and biogel a-1.5 m. the enterotoxic activity was eluted from the biogel column in two peaks. approximately 50-70% of the enterotoxi ...19827109966
assignment of ada, itpa, ak1, and ak2 to chinese hamster chromosomes. genetic and structural evidence for the conservation of mammalian autosomal synteny.interspecific somatic cell hybrids formed by fusion of mouse cl1d cells with chinese hamster primary spleen or fibroblast cells were used to form a clone panel with members retaining different combinations of chinese hamster chromosomes and isozyme markers. concordant segregation analysis of isozymes and chromosomes among clone panel members enabled the provisional assignment of ada, itpa, and ak1 to chinese hamster chromosome 6. diphtheria toxin selection for chinese hamster chromosome 2 segreg ...19827153494
mapping of polypeptide genes by two-dimensional gel electrophoresis of hybrid cell extracts.a series of 18 chinese hamster x human somatic cell hybrid subclones segregating human chromosomes were analyzed by two-dimensional gel electrophoresis to determine the chromosomal location of the human genes responsible for the expression of specific proteins. two independent methods, side by side comparison and double label autoradiography-fluorography, were used to identify the human proteins that were unambiguously resolved from those of the chinese hamster (ch). of the 83 human spots resolv ...19827159713
chinese hamster nuclear proteins. an electrophoretic analysis of interphase, metaphase and nuclear matrix preparations.a comparison, by two-dimensional gel electrophoresis, of total interphase nuclear, metaphase chromosomal and nuclear matrix proteins from chinese hamster v-79 cells was undertaken to examine the distribution of these proteins during mitosis. we have found a number of differences among these populations, although the two-dimensional gel patterns are generally similar. the most striking observation is that a loose cluster of six interphase nuclear polypeptides, with isoelectric points in urea betw ...19827160383
the effect of sulfhydryl compounds on sister-chromatid exchanges. ii. the question of cell specificity and the role of contrast with earlier reports on the induction of sister-chromatid exchanges (sces) by sh compounds in cell lines of the chinese hamster, cysteine, cysteamine and cystamine did not cause an increase of the sce frequency in human lymphocyte cultures. differences in the treatment protocols or variations of the brdurd concentration had no effect on the induction of sces by these substances. the inclusion of h2o2 and comparative investigations with v79 cells of the chinese hamster showed that the ...19827062929
stereo electron microscopy of enamel crystallites.stereo microscopy was used to examine enamel crystallites in routine thin sections of rat and chinese hamster incisors. freeze-fracture replicas were also made of rat incisor enamel. these studies revealed that enamel crystallites are thin, flat, twisting ribbons of unmeasurable length and uniform width. images previously interpreted as hexagonal crystallites are due to perspective distortion caused by oblique views along cut segments of these flattened ribbons exaggerated by curling, which occu ...19826958709
immunoglobulin as the major low density lipoprotein binding protein in plasma.plasma from normal humans and chinese hamsters was shown to contain material which binds to low density lipoproteins (ldl). the binding capacity of these plasmas was demonstrated by passive hemagglutination against human ldl-coated red blood cells. the plasmas were fractionated by affinity chromatography, gel filtration and electrophoresis. immunologic analyses of these fractions showed that igm and iga were the major plasma proteins responsible for the ldl binding titers of human and hamster pl ...19827138617
chinese hamster cell mutant resistant to ml236b (compactin) is defective in endocytosis of low-density lipo-protein.a fungal metabolite, ml236b (compactin), isolated from penicillium citrinum, is a specific inhibitor of 3-hydroxy-3-methylglutaryl (hmg)-coenzyme a reductase (ec three ml236b-resistant (ml236br) mutants, mf-1, mf-2, and mf-3, were isolated from v79 after n-methyl-n'-nitro-n-nitrosoguanidine mutagenesis. the fluctuation test showed 2.2 x 10(-6) mutants per cell per generation of a spontaneous mutation frequency of ml236br clones. these ml236br clones showed a four- to fivefold-higher r ...19827162516
pleiotropic mutations of lysosomal function in human patients and in chinese hamster ovary cells.the biosynthesis of lysosomal enzymes entails a complex series of events. the nascent proteins enter the endoplasmic reticulum for glycosylation. phosphorylation of the enzymes subsequently occurs in the golgi area. equipped with a phosphomannose recognition marker, the enzymes are bound to specific receptors and translocated to lysosomes. mutations are known in the following steps: early glycosylation (cho cells), phosphorylation (patients with i-cell disease and pseudo-hurler polydystrophy), a ...19827163219
hepatocyte-mediated production of sister chromatid exchange in co-cultured cells by acrylonitrile: evidence for extra cellular transport of a stable reactive study the possibility that liver metabolism of acrylonitrile (acn) could produce a stable carcinogenic metabolite that causes the brain tumors produced by acn, the ability of hepatocytes to generate a stable transportable mutagenic metabolite in culture was studied. acn did not produce sister chromatid exchanges (sces) in chinese hamster ovary (cho) cells, but a significant increase was produced when cho cells were co-cultured with freshly isolated rat hepatocytes. induction of sce in cho cel ...19827165873
assignment of the structural gene coding for albumin to human chromosome 4.albumin is a developmentally regulated serum protein synthesized in the liver mainly during adulthood. family studies using variant forms of albumin established autosomal linkage between albumin and group-specific component protein (gs). since gc has been assigned to human chromosome 4, albumin can be indirectly assigned to the same chromosome; however no direct assignment has been made. recently, the human albumin cdna probe has been isolated and characterized. it thus permits a direct chromoso ...19827166310
mutagenicity and dominant lethal test of kojic acid--ames test, forward mutation test in cultured chinese hamster cells and dominant lethal test in mice.the mutagenicity of kojic acid was studied by means of reversion mutation test in bacteria (ames test), forward mutation test in cultured chinese hamster cells and dominant lethal test in mice. a positive result was obtained only in ames test (ta 98, 1535 and 100) which was not modified by the presence of s-9 fraction. thus, it is concluded that although kojic acid is a weak mutagen in bacteria, it is nonmutagenic in eukaryotic systems either in vivo or in vitro.19827169638
peripheral neurology of the diabetic chinese hamster.genetically diabetic chinese hamsters were examined anatomically and physiologically for evidence of peripheral neuropathy. control animals were from non-diabetic strains. conduction velocities in both motor and sensory components of the hind limb nerves were reduced 16-22% in diabetic compared with control hamsters. however, there was no reduction in nerve fibre diameters or other signs of abnormal morphology that could be correlated with these physiological effects. it is concluded that the di ...19827173521
acute and genetic toxicity of 1-nitropyrene and its fate after single oral doses to rats.the mammalian acute and genetic toxicity of 1-nitropyrene (np) was studied because this and other nitroarenes are highly mutagenic toward bacteria and have been identified in emissions from combustion processes. a suspension of np did not cause observable signs of acute toxicity and was not lethal when administered to male and female rats at single oral doses as high as 5.0 g/kg. histological examination of stomach, intestine, lung, heart, spleen, pancreas, adrenal, and kidney from rats euthaniz ...19827175968
selective linkage disruption in human-chinese hamster cell hybrids: deletion mapping of the leus, hexb, emtb, and chr genes on human chromosome 5.chinese hamster-human interspecific hybrid cells, which contain human chromosome 5 and express four genes linked on that chromosome, were subjected to selective conditions requiring them to retain one of the four linked genes, leus (encoding leucyl-trna synthetase), but lose another, either emtb (encoding ribosomal protein s14) or chr. cytogenetic and biochemical analyses of spontaneous segregants isolated by using these unique selective pressures have enabled us to determine the order and regio ...19827177110
[ph dynamics in the lysosomes and cytoplasm of tissue culture cells measured intravitally using the indicator dye neutral red].a method of ph determination in the cytoplasm and individual lysosomes of intact living cultured cells is proposed using an indicator dye--neutral red (nr). the ph value of an investigated structure stained with nr is from the ratio between its optical densities at two wave lengths, the one corresponding to the isobestic point (lambda = 470 nm), and the other--to the absorption maximum of the neutral form of the dye (lambda = 450 nm). this method enabled us to make ph determination in the range ...19827179473
membranous structures in pinealocytes of the chinese hamster (cricetulus griseus); are they annulate lamellae?pinealocyte ultrastructure in the normal and spontaneously diabetic chinese hamster has been studied. a literature comparison shows it to be similar to the pineal of the syrian hamster; however, the incidence of membranous structures is more frequent in the chinese as compared with the syrian hamster. stacks of membranous structures were present in pinealocytes of all animals in this study and, therefore, appear to be regularly occurring organelles in the pineal of this species. there are analog ...19827111333
activity of nitro-polynuclear aromatic hydrocarbons in the sister chromatid exchange assay with and without metabolic activation.nitro-polynuclear aromatic hydrocarbons are found in diesel particulates. these compounds are potent mutagens in the ames test. to determine whether nitro-polynuclear aromatic hydrocarbons are active in a mammalian cell assay, 1-nitropyrene, 1,8-dinitropyrene, 2-nitrofluorene, and 4-nitrobiphenyl were incubated with cultures of chinese hamster ovary cells. the frequency of sister chromatid exchange (sce) was measured in the presence and absence of rat liver s-9 mix. the addition of s-9 mix resul ...19827067667
different optimal pha concentrations for stimulation of chinese hamster lymphocytes in cultures supplemented with foetal calf serum or horse serum.chinese hamster lymphocyte cultures were supplemented with foetal calf serum (fcs) or hose serum (hs). addition of 2-mercaptoethanol (2-me) to cultures supplemented with these sera resulted in a marked increase lymphocyte proliferation. the pha concentrations necessary for optimal lymphocyte stimulation were much lower in cultures supplemented with hs than with fcs. phytohaemagglutinin (pha) concentrations optimal for stimulation of a given number of lymphocytes in cultures supplemented with fcs ...19827045230
[two european spirometra forms (cestoidea: diphyllobothriidae) with different sparganum growth factors].european spirometra forms corresponding to s. erinaceieuropaei in morphology, host specificity and periodical destrobilation were tested for a sparganum growth factor (sgf "mansonoides") acting upon hypophysectomized male rats. a polish form as well as thai and burmese forms did not show a sgf "mansonoides". the polish form partially caused increased growth in normal laboratory mice (similar to a form from thailand) and in cricetulus griseus (sgf "non-mansonoides", restricted by host resistance) ...19827081763
the human genes for s-adenosylhomocysteine hydrolase and adenosine deaminase are syntenic on chromosome 20.human-chinese hamster cell hybrids and a monoclonal antibody to human s-adenosylhomocysteine hydrolase were used to identify chromosome 20 as the location of the human gene for this enzyme. the gene for adenosine deaminase had previously been mapped to this chromosome. the activity of s-adenosylhomocysteine hydrolase is dependent in vivo on that of adenosine deaminase, since the substrates for the deaminase, adenosine and deoxyadenosine, respectively, inhibit and inactivate s-adenosylhomocystein ...19827079734
zinc-induced resistance to alkylating agent toxicity.suspension cultures of chinese hamster ovary cells and three derived cadmium-resistant variants were exposed to 100 microm zncl2 prior to treatment with the alkylating agent, melphalan, and cytotoxicity was then determined by measuring colony-forming ability. a 10-fold or greater enhancement in survival of all zinc-pretreated cultures subsequently exposed to melphalan was observed which was unrelated to metallothionein induction capacity. although the maximum achievable protection afforded by zi ...19827093947
perturbation of lipid metabolism by palmitic acid in chinese hamster v79-r cells.1. the addition of palmitic acid or myristic acid to a medium containing delipidated fetal bovine serum resulted in severe inhibition of v79-r cell growth. the degree of inhibition by palmitic acid was concentration dependent. simultaneous addition of oleic acid protected the cells from the inhibition by palmitic acid. 2. in the presence of palmitic acid, total phospholipid and triacylglycerol per cell increased to 2- and 13-fold, respectively. 3. palmitic acid caused an increase in the proporti ...19827096310
cytotoxicity and mutagenicity of dinitrotoluenes in chinese hamster ovary cells.technical grade dinitrotoluene (dnt), a mixture composed predominantly of 2,4- and 2,6-dnt but containing lesser amounts of 2,3-, 2,5-, 3,4- and 3,5-dnt, has been shown to be a hepatocarcinogen in rats, the mutagenicity of these compounds has been evaluated using the cho/hgprt system, a quantitative mammalian somatic cell mutational assay. dinitrotoluenes were tested for their ability to induce mutation to 6-thioguanine (tg) resistance in the presence and absence of microsomal preparations (pms) ...19827057784
amplification of the metallothionein-i gene in cadmium- and zinc-resistant chinese hamster ovary cells.a subclone of chinese hamster ovary cells, r40f, has been selected for its unusually high resistance to lethal concentrations of cd and zn. although there is a 33% loss in cd resistance when r40f cells are cultured in the absence of exogenous metals, the zn resistance remains unaltered. these cells are 80% tetraploid and demonstrate an increased capacity for metallothionein protein synthesis. when compared to wild type cells cultured in the absence of exogenous metals, r40f cells exposed to 200 ...19827096350
patulin, a further clastogenic mycotoxin, is negative in the sce assay in chinese hamster v79-e cells in vitro.patulin is a potent inducer of chromatid-type aberrations in chinese hamster v79-e cells, but loses its activity when 9000 g supernatant of rat-liver homogenate is added. the narrow dose range of patulin clastogenicity shows a quantitative relationship between absolute amount of mycotoxin applied and the number of indicator cells treated. within a dose range permitting survival of v79-e, patulin does not induce an increase of the sce rate. it is suggested that patulin clastogenicity is caused by ...19827057787
modulation of mammalian cell growth by a choline analog, n-isopropylethanolamine.the choline analog, n-isopropylethanolamine (ipe), inhibits the growth of both chinese hamster ovary cho-k1 and mouse l-m cells by two kinetically distinct mechanisms; i, a reversible and concentration-dependent reduction in the logarithmic population doubling rate and the saturation density of cultures by low ipe levels in the media; and ii, an irreversible and time-dependent killing of cells by high ipe concentrations. both types of inhibition are independent of media depletion, cell density, ...19827084974
effects of praziquantel, a new antischistosomal drug, on the mutation and transformation of mammalian cells.praziquantel (pq), a tetrahydroquinoline derivative, is a new and clinically effective antischistosomal drug, which has been shown to lack or to possess very weak mutagenic activity. however, in bacteria, this compound can act as a weak comutagen that increases the mutagenicity of several chemical mutagens and carcinogens. we have found that pq can act as a very weak comutagen in animal cells. at 10 to 50 micrograms/ml, pq increased the mutagenicity of n-methyl-n'-nitro-n-nitrosoguanidine and 2- ...19827083161
selective phagocytosis of crystalline metal sulfide particles and dna strand breaks as a mechanism for the induction of cellular transformation.crystalline nis, cus, cos2, and cds particles were actively phagocytosed by cells and potently induced morphological transformation of syrian hamster embryo cells in a concentration-dependent fashion. in contrast, the respective amorphous metal sulfide particles (amorphous nis, cus, cos, and cds) were not as actively phagocytosed by cultured cells and, in comparison to the crystalline form of these compounds, induced considerably less morphological transformation at both cytotoxic and noncytotox ...19827083166
radiosensitization by non-nitro compounds.the effects of 23 non-nitro compounds on the radiosensitivity of hypoxic chinese hamster v79-379a or e. coli ab 1157 cells in vitro are outlined. imidazole derivatives substituted with several alternative electron-withdrawing groups are described; the dicyanovinyl function conferred considerable radiosensitizing activity. 2,4,5-tribromoimidazole and 2,4-dinitrophenol may show unusual radiosensitizing activity because of interference with oxidative phosphorylation. attempts to influence radiosens ...19827050038
genotoxicity of cocoa examined by microbial and mammalian systems.unroasted or roasted cocoa powder dispersed in water and applied to chinese hamsters by stomach tube caused elevated numbers of sces in the sister-chromatid exchange test (bone-marrow cells). roasted cocoa freed from fat produced distinctly higher sce values with a linear dose-response relationship, whereas cocoa butter had no influence on sce levels. positive results in the sce test (1.5-fold values of the controls) were obtained after application of about 5 g cocoa/kg b.w. presumably, because ...19827045646
development of a laboratory animal model for infectious bovine keratoconjunctivitis.guinea pigs, gerbils, voles, golden hamsters and chinese hamsters exposed to experimental infection with moraxella bovis by ocular instillation or associated routes showed transient infections only and no clinical signs. five strains of mice were of similarly low susceptibility but another, the c57 bl strain, was relatively susceptible and treatment with corticosteroid before infection regularly produced keratoconjunctivitis. this system therefore offers a promising model for studies on infectio ...19827045996
mutagenicity of the optical isomers of the diastereomeric bay-region chrysene 1,3-diol-3,4-epoxides in bacterial and mammalian cells.the mutagenic activities of the four optically pure (+)- and (-)-enantiomers of the two diastereomeric bay-region chrysene 1,2-diol-3,4-epoxides were evaluated in histidine-dependent strains of salmonella typhimurium and in cultured chinese hamster v79 cells. in strain ta98 of s. typhimurium, (-)-1 alpha, 2 beta-dihydroxy-3 beta, 4 beta-epoxy-1,2,3,4-tetrahydrochrysene was 5 to 10 times more active than the other three optical isomers. however, in strain ta100 of s. typhimurium and in chinese ha ...19827046912
in vitro mutagenic activity of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (dtic) in eukaryotic and prokaryotic cells.the in vitro mutagenic activity of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (dtic), has been studied in bacteria and chinese hamster cells with and without metabolic activation by rat liver microsomes. dtic was found to be highly mutagenic in the two systems. it is noteworthy that dtic in the prokaryotic systems did not require metabolic activation to be effective. by comparing the mutagenic activity on bacteria of dtic and of its monomethyl-and hydroxy-methyl-derivatives (mic and hmi ...19827046979
further evaluation of the biken test (modified elek test) for detection of enterotoxigenic escherichia coli producing heat-labile enterotoxin and application of the test to sampling of heat-stable enterotoxin.a total of 2,229 strains of escherichia coli isolated from subjects with traveller's diarrhea were tested for heat-labile enterotoxin production by the biken test (honda et al., j. clin. microbiol. 13:1--5, 1981). results of the biken test showed a 99.0% coincidence with those obtained by chinese hamster ovary cell assay. the use of antiserum against e. coli heat-labile enterotoxin gave sharper and clearer results than did the use of antiserum against cholera enterotoxin. samples for heat-stable ...19827050166
high intralysosomal levels of lipoprotein cholesterol influence the endocytic activity and acid hydrolase content of ch-23 fibroblasts.lipoprotein extracts isolated from hyperlipemic rabbit serum were used to study the effects of abnormal lipid levels on the functions of the lysosomal system in chinese hamster ch-23 fibroblasts. the ability of cells enriched with lipid to endocystose [3h]inulin was largely unimpaired and utilising density gradient fractionation procedures the fusion between incoming inulin and low density lysosomes ladened with esterified cholesterol could be demonstrated. studies in which cells were exposed to ...19827055620
12-o-tetradecanoyl-phorbol-13-acetate and its relationship to sce induction in syrian and chinese hamster cells.12-o-tetradecanoyl-phorbol-13-acetate (tpa) in conditions that produce enhancement of ultraviolet light (uv) and x-irradiation syrian hamster embryo cell (hec) transformation did not cause further increase in the sister chromatid exchange (sce) frequency induced by uv and x-irradiation, two physical carcinogens that differ in their mode of dna interaction and efficiency of sce induction. several factors which might influence sce induction by tpa were studied on hec and chinese hamster v79-4 cell ...19827067669
enhancement of sister-chromatid exchanges by tumour promoters.the effect of the tumour promoters tpa, phenobarbitone and saccharin on the production of sister-chromatid exchanges (sce) was studied. tpa produced a small but significant increase of sce in chinese hamster cell lines v-79 and cho, and in a hybrid clone formed by fusion of cho with rat liver epithelial cells. the enhancement of sce by tpa was not affected by the type of culture medium, heat-inactivated bovine serum, or the batch of tpa. in the presence of exogenous l-cysteine the enhancement of ...19827082559
neoplastic transformation of syrian hamster embryo cells by bisulfite is accompanied with a decrease in the number of functioning replicons.bisulfite, a chemical that at neutral ph does no induce mutations at two loci in chinese hamster v-79 cells, induces transformation of syrian hamster embryo cells. although bisulfite affects dna metabolism, there was no evidence of bisulfite-induced dna damage. bisulfite induced no excision repair replication, caused no dna strand breaks detectable in alkaline sucrose gradients, had no effect on the size distribution of dna nascent daughter strands, and did not affect excision on post-replicatio ...19827067034
ultrasonically induced nuclear aberrations in an in vitro multicellular tumour system.chinese hamster v-79 cells, attached to an acoustically transparent membrane and emt6/ro mouse mammary sarcoma cells as small multicellular spheroids or in suspension, were exposed to therapeutic intensities of 1 mhz ultrasound (0-10 w/cm2) and examined for the production of atypical nuclear or chromosomal aberrations. in the monolayer configuration no abnormalities occurred. in multicell spheroids or suspension cells 3 classes of abnormalities were found: (1) pyknotic/irregular nuclei; (2) lyse ...19827082914
morphology, proliferation, and differentiation of undifferentiated spermatogonia in the chinese hamster and the ram. 19827103128
human chromosomes control growth of human-chinese hamster somatic cell hybrids.several independent human-chinese hamster hybrid cell lines have been monitored for growth rate and chromosome composition. the rate of growth, as indicated by doubling time during log phase, was positively correlated with the number of human chromosomes, and human chromosomes 3 and 21 were present in stable hybrid cell lines more frequently than expected.19827101100
cultivation of bacteroides fragilis in tissue culture.the capacity of animal cells to support the growth of obligate anaerobes was shown by inoculating bacteroides fragilis and bacteroides thetaiotaomicron into cultures of vero, hela, chinese hamster ovary, and chinese hamster lung cells. from an extremely small inoculum (nearly 1 cfu), b. fragilis multiplied up to 10(8) cfu/ml during aerobic cultivation in l-15 medium containing kanamycin sulfate (50 micrograms/ml) and 5% fetal bovine serum (total depth, 3-5 mm). infecting bacteria formed a cluste ...19827086198
[isolation of hybrid clones of human-rodent somatic cells].mutant cells of chinese hamster or mouse were fused with normal embryonic human cells. the fusion was induced by polyethylene glycol. the eagle medium containing hypoxanthine, aminopterine, thymidine, glycine, and ouabain served as a selective medium. the parent cells were completely destroyed in the selective medium. the hybrid cells formed colonies which were isolated and reproduced for cytogenetic analysis. the cytogenetic analysis has confirmed the hybrid origin of the isolated clones.19826960934
comparison of the subcellular distribution of monomeric 239pu and 59fe in the liver of rat, mouse, and syrian and chinese hamsters. 19827063601
genotoxic activity of the aminophenols as evidenced by the induction of sister chromatid exchanges.1 most hair dyes contain the structural isomers ortho-, meta- and para- aminophenol which were investigated concerning their ability to induce sister chromatid exchanges (sce) in cultured human lymphocytes in vitro and in chinese hamster bone marrow cells in vivo. 2 in vitro only ortho-aminophenol significantly induced sce in a dose-dependent manner. 3 in vivo none of the structural isomers increased significantly the sce frequency. 4 it is concluded that ortho-aminophenol is a weak directly act ...19827173923
fatty acid modification of newcastle disease virus glycoproteins.the fatty acid acylation of newcastle disease virus hemagglutininin-neuraminidase and fusion glycoproteins was assayed. [3h]palmitate label was associated with cytoplasmic fusion proteins (f0 and f1) and virion-associated f1. in contrast, there was no detectable [3h]palmitate label associated with the hemagglutin-neuraminidase protein in newcastle disease virus-infected chinese hamster ovary cells or chicken embryo cells or in virions released from these cells. thus, fatty acid modification may ...19827109029
in vitro stimulation of cell growth by hepatic stimulator extract of normal weanling or adult regenerating rat liver called hepatic stimulator substance (hss) stimulates incorporation of tritiated thymidine ([3h]dthd) into liver dna. in vivo, it is organ specific, species nonspecific, displays diurnal rhythm, and has a molecular weight of approximately 10,000-20,000. it has now been further characterized in vitro. hss retained organ specificity, stimulating normal adult hepatocytes in primary culture, the htc, plc, and mh1c1 hepatoma cell lines, and ...19827199825
induction of sister-chromatid exchanges, cell-cycle delay and chromosomal aberrations by human urine concentrates.human urine concentrates, prepared with the use of xad-2 resin, are shown to be potent inducers of sister-chromatid exchanges, and especially of chromosomal damage and cell-cycle delay in chinese hamster ovary cells. no indications for differences in mutagenic activity were found between concentrates prepared from the urine of smokers, non-smokers or patients with alcoholic cirrhosis of the liver. these effects were obtained without metabolic activation in vitro. experiments including variations ...19827201069
12-o-tetradecanoylphorbol-13-acetate (tpa) induces sister-chromatid exchanges and delays in cell progression in chinese hamster ovary and human cell lines.the tumor promoter 12-o-tetradecanoylphorbol-13-acetate (tpa) induced a 20-45% increase in sister-chromatid exchange (sce) frequency in chinese hamster ovary cells (cho) and in 2 sv40-transformed human fibroblast cell lines (gm637 and xp12ro) at concentrations up to 1 microgram/ml. the increase was independent of the time at which the cells were fixed after treatment and was not due to an impurity in the tpa preparation or to increased incorporation of bromodeoxyuridine into the dna. there was n ...19827201071
inability of methapyrilene to induce sister chromatid exchanges in vitro and in vivo.the induction of sister chromatid exchanges (sce) by the hepatocarcinogen methapyrilene hydrochloride was investigated using appropriate in vitro and in vivo mammalian cell systems. methapyrilene, even at the maximum tolerated dose, did not induce sce in chinese hamster ovary cells (cho) or when cho cells or hamster lung fibroblasts, v-79, were cocultivated with early cultures of rat liver epithelial cells, which are known to metabolize different classes of chemical carcinogens to active forms. ...19827127299
comparative dna/dna reassociation kinetics in three hamster species.1. three major dna repetition classes can be distinguished in the genomes of three hamster species mesocricetus auratus, cricetulus griseus, and phodopus sungorus sungorus: a very fast reassociating fraction of about 13% of the dna, a fast reassociating fraction comprising 10-23% of the dna, and a slowly reassociating fraction containing single-copy sequences of 63-78% of hamster dna. 2. in the dna of the syrian and djungarian hamster 43%-53%, and in the dna of the chinese hamster 80% of the sin ...19827128102
carcinogenic and mutagenic activity of an alkaloidal extract of senecio nemorensis ssp. fuchsii.the alkaloidal residue obtained after extraction of dried and pulverized senecio nemorensis ssp. fuchsii contains two pyrrolizidine alkaloids, i.e. fuchsisenecionine and senecionine. in a chronic experiment doses of 8 mg/kg and 40 mg/kg b.w. of the alkaloidal extract were given five times a week by gavage to male and female sprague-dawley rats. the study was terminated after 114 weeks. repeated serum analysis demonstrated a dose-related elevation of serum glutamic oxalacetic transaminase (sgot), ...19827199918
arginase as an inhibitory principle in liver plasma membranes arresting the growth of various mammalian cells in vitro.plasma membranes prepared from rat livers inhibited the in vitro growth of various mammalian cells including hepatoma cells in a concentration-dependent manner, showing almost complete arrest of cell growth at 0.1 mg protein/ml. some of these cells tested, i.e., leukemia (l1210 and p388) and myeloma (p3-ns-1/1-ag4-1) cells, were labile in the presence of plasma membranes (losing the viability), and cho (chinese hamster ovary) cells became round without detaching from the substratum. the culture ...19827200804
temperature dependence of ultrasound-induced cell killing: the role of membrane fluidity.chinese hamster cells in suspension were exposed to 20 khz ultrasound (us) at 54 w/cm2 and various temperatures between 2 and 44 degrees c. activation energies were 2.6 and 24 kcal/mole below and above 35 degrees c, respectively. procaine, a local anaesthetic drug known to increase membrane fluidity, enhanced cellular inactivation by us above 41 degrees c, increasing the activation energy to 62 kcal/mole. the inactivation of the bacterium salmonella typhimurium by us was also dependent on the ex ...19827126276
linkage of the leus, emtb, and chr genes on chromosome 5 in humans and expression of human genes encoding protein synthetic components in human--chinese hamster hybrids.we isolated interspecific hybrids between normal human leukocytes and a chinese hamster ovary cell line that has mutations in three genes, leus, emtb, and chr, all of which are linked to chromosome 2. the conditionally lethal mutation in the leus gene in this cell line affects leucyl-trna synthetase and renders the cell line nonviable at 39 degrees c. the mutation in the emtb locus alters ribosomal protein s14 and results in the cell line being resistant to the protein synthesis inhibitor, emeti ...19829732752
ntp technical report on the toxicity studies of castor oil (cas no. 8001-79-4) in f344/n rats and b6c3f1 mice (dosed feed studies).castor oil is a natural oil derived from the seeds of the castor bean, ricinus communis. it is comprised largely of triglycerides with a high ricinolin content. toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to f344/n rats and b6c3f1 mice of both sexes for 13 weeks. genetic toxicity studies also were performed and were negative for mutation induction in salmonella typhimurium, for induction of sister chromatid exchang ...198212209174
exocytosis of pinocytic contents by chinese hamster ovary cells.the extent of exocytosis of pinocytic vesicle contents was studied in suspension-cultured chinese hamster ovary (cho) cells using horseradish peroxidase (hrp) as a pinocytic content marker. hrp was shown to be internalized via fluid-phase pinocytosis in cho cells. after an hrp pulse of 2.5-10 min a rapid decrease of 30-50% in cell-associated hrp activity was observed within 10-20 min at 37 degrees c. during this time the loss of cell-associated hrp was accompanied by an equivalent increase in ex ...19827118995
the regulation of ionic nickel uptake and cytotoxicity by specific amino acids and serum components.the effects of serum components and amino acids on the uptake and cytotoxicity of nicl2 were examined in cultured chinese hamster ovary (cho) cells. cho cells maintained in a minimal salts/glucose medium accumulated 10-fold more(63)ni than did cells maintained in complete medium supplemented with 10% fetal bovine serum. cell-surface binding of(63)ni appeared to account for the majority of this increased accumulation of cell-associated nickel observed in the simple maintenance medium since such i ...198224272136
acid glycohydrolase in chinese hamster with spontaneous diabetes. iv. diabetes- and line-dependent variation in plasma enzyme activity.the activity of five glycohydrolases was measured in the plasma of chinese hamsters from eight highly inbred lines in the upjohn colony. the diabetic animals showed elevated activities of plasma beta-d-galactosidase, n-acetyl-beta-d-glucosaminidase and n-acetyl-beta-d-galactosaminidase but similar activities of plasma alpha-d-glucosidase and alpha-d-galactosidase to the nondiabetic animals. line-specific variation was observed in all five enzymes and anomalies were especially evident in n-acetyl ...1982216599
hypothalamic changes in diabetic chinese hamsters. a semiquantitative, light and electron microscopic study.eight male congenitally diabetic chinese hamsters (dch) and eight heterozygotic controls were studied for a period of about 20 months. final glycemia and body weight were significantly higher in dch (p less than 0.001). after whole body perfusion brains were removed and processed for light and electron microscopy. qualitative and quantitative light microscopic studies of semithin sections of hypothalami revealed significant changes in dch. accumulation of lipid droplets was found in the external ...19827144136
[enhancement of the lung and skin injuries in chinese hamsters by combined application of radiation and cyclophosphamide]. 19827177791
plasma glycoproteins of diabetic and normal chinese hamsters. 19827075720
phenoxy acid herbicides cause peroxisome proliferation in chinese increase in either the size or amount of peroxisomes was obtained in the liver cells of chinese hamsters after the animals were exposed to the phenoxy herbicides 2,4-dichlorophenoxyacetic acid (2,4-d) or 4-chloro-2-methylphenoxyacetic acid (mcpa). at the dose level studied, 2,4-d was found to be more potent than mcpa in increasing the number of peroxisomes. a phenoxy acid derivative, clofibrate, one of the peroxisome proliferators known to possess carcinogenic properties in rodents, appeared ...19827134925
newly synthesized hypoxia-mediated drugs as radiosensitizers and cytotoxic agents.chinese hamster cells in culture were used to compare the radiosensitizing efficiency and cytotoxicity of misonidazole with several 2, 4 and 5 substituted nitroimidazoles. the two substituted compounds (sr 2508 and sr 2555) are similar to misonidazole in radiosensitizing effectiveness, but are significantly less toxic to hypoxic cells. this reduced cytotoxicity may result from either slower drug penetration or slower removal of non-protein sulfhydryl compounds (npsh). the compound mjl-1-191-vii ...19827061257
ultrastructural observations on the pineal gland of the chinese hamster, cricetulus griseus. i. the superficial pineal.the ultrastructure of the pineal parenchymal cells, pinealocytes and glia-like cells, of the chinese hamster (cricetulus griseus) is described. pinealocyte nuclei contain spindle-shaped inclusions consisting of bundles of closely packed parallel filaments of about 8 nm in thickness. mitochondria contain lamellar and tubular cristae. smaller and larger mitochondria are usually localized separately in individual pinealocytes. flattened mitochondria contain two to four closely arranged, unusual lam ...19827060102
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