TitleAbstractYear(sorted ascending)
an "external" rna removable from mammalian cells by mild proteolysis.brief exposure of chinese hamster ovary cell monolayers prelabeled with [(32)p]phosphate and [(3)h]leucine to 1 mug/ml of trypsin under conditions in which cells remain fully viable causes the release of macromolecular (32)p and (3)h. whereas ribonuclease treatment was found to affect markedly both the (32)p and (3)h radioactivity, pronase treatment had little effect on the macromolecular (32)p. treatment of cells prelabeled with [(3)h]glucosamine and [(32)p]phosphate with insolubilized papain a ...19744531029
non-repairable strand breaks induced by 125i incorporated into mammalian dna.when (125)i is incorporated into chinese hamster dna (via (125)i-labeled iododeoxyuridine) and the cells are stored at 77 degrees k, the resulting decays of the isotope cause 4 to 5 breaks/single-strand per disintegration. on the average, about 50% of these breaks are repaired. in contrast, under the same conditions of storage and in the same range of total strand breaks/cell, 70-100% of the breaks induced by x-radiation are repaired. thus, the extreme toxicity of (125)i when incorporated into d ...19744531021
some biochemical properties of chinese hamster cells sensitive and resistant to actinomycin d.a graded series of drug-resistant chinese hamster sublines has been examined for biochemical changes accompanying resistance to actinomycin d. the most highly resistant subline, dc-3f/ad x, is maintained at 10 microg/ml of the antibiotic. it was shown that over 250 times more actinomycin d is required to inhibit rna synthesis in this subline than in the parental dc-3f line. the dc-3f/ad x subline was also shown to have a somewhat reduced capacity to transport uridine as compared to parental cell ...19744474176
the induction of ouabain-resistant mutants by n-methyl-n'-nitro-n-nitrosoguanidine in chinese hamster cells. 19744461312
chromosome aberrations in metaphase ii oocytes of chinese hamster (cricetulus griseus). i. the sensitivity of the pre-ovulatory phase to triaziquone. 19744437573
studies in the diabetic chinese hamster: light microscopy and autoradiography of pancreatic islets. 19744615023
purine mutants of mammalian cell lines. i. accumulation of formylglycinamide ribotide by purine mutants of chinese hamster ovary cells. 19744477717
dna-dependent rna polymerase activity of chinese hamster kidney cells sensitive to high concentrations of alpha-amanitin. 19744474058
selective enhancement of cytoplasmic protein species and continued histone synthesis during inhibition of dna synthesis in temperature-sensitive chinese hamster cells. 19744472590
cholesterol metabolism in the diabetic chinese hamster. 19744448326
streptozotocin-diabetes in the chinese hamster. long-term effects on the light microscopic structure of the pancreatic islet tissue, liver and kidney. 19744280870
aortic glucose metabolism in the diabetic chinese hamster. 19744217299
morphological characterization of membrane systems in a- and b-cells of the chinese hamster. 19744217292
the diabetic chinese hamster: in vitro insulin and glucagon release; the "chemical diabetic";; and the effect of diet on ketonuria. 19744217291
nuclear and cytoplasmic pools of deoxyribonucleoside triphosphates in chinese hamster ovary cells. 19744472692
effects of x-irradiation on dna precursor metabolism and deoxyribonucleoside triphosphate pools in chinese hamster cells. 197410881709
the effects of ionizing radiation on the kinetics of dna replication in synchronized chinese hamster ovary cells. 197410881700
ultrastructural changes in the nuclear envelope during mitosis of chinese hamster cells: a proposed mechanism of nuclear envelope reformation. 19744610163
letter: studies on the radiosensitizing effect of oxygen in chinese hamster cells. 19744548052
[a comparison between incorporation of the precursors of the a--t and g--c dna base pairs into the chromosomes of the chinese hamster]. 19744477721
sister chromatid exchanges induced in chinese hamster cells by uv irradiation of different stages of the cell cycle: the necessity for cells to pass through s. 19744473707
killing of chinese hamster cells in vitro by heating under hypoxic or aerobic conditions. 19744465105
chiasma in the xy bivalent of the chinese hamster. 19744371595
polyribosomal and particulate distribution of lysyl- and phenylalanyl-transfer ribonucleic acid synthetases.1. only two aminoacyl-trna synthetases from chinese hamster ovary cells are found associated with ribosomes and polyribosomes. 2. phenylalanyl-trna synthetase activity is found with the 60s subunit, 80s monoribosome and individual polyribosomes. an additional 15s form of the enzyme is also seen. 3. lysyl-trna synthetase activity is found in a form of about 20s and associated with ribosomal subunits and polyribosomes. the ribosomal subunits having lysyl-trna synthetase activity are about 6s large ...19744219282
letter: x-irradiation of mitotic chinese hamster cells. ii. evidence for cell-doublet survival response before karyo-and cytokinesis. 19744547759
the fate of pyrimidine dimers in the dna of ultraviolet-irradiated chinese hamster cells. 19744472368
temperature-sensitive mutants in populations of chinese hamster cells. 19744432118
effect of 239puo2 particle number and size on the frequency and distribution of chromosome aberrations in the liver of the chinese hamster. 19744428016
the effects of treatments with 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide in darkness and in light on survival and progression in chinese hamster ovary cells in vitro. 19744858377
dynamics of the ribosomal rna content and growth of synchronized chinese hamster cells. 19744433925
thermally enhanced radioresponse of cultured chinese hamster cells: damage and repair of single-stranded dna and a dna complex. 19744422045
studies on a chinese hamster line that is temperature sensitive for the commitment to dna synthesis. 19744367532
biosynthesis of biopterin by chinese hamster ovary (cho k1) cell culture. 19744210503
chinese hamster hypoxanthine-guanine phosphoribosyltransferase. purification, structural, and catalytic properties. 19744368495
characterization of a chinese hamster cell with a temperature-sensitive mutation in folate metabolism. 19744472030
an electron microscopy study of the effects on dibutyryl cyclic amp on chinese hamster ovary cells. 19744369770
sister chromatid exchanges induced by light flashes to 5-bromodeoxyuridine- and 5-iododeoxyuridine substituted chinese hamster chromosomes. 19744135474
banding and chromatid separation in chinese hamster chromosomes. 19744134900
thermal sensitivity and the effect of elevated temperatures on the radiation sensitivity of chinese hamster cells. 19744859562
comparative frequency of dominant and recessive markers for drug resistance in chinese hamster cells. 19744834409
enhancement of dna synthesis in a mammalian cell-free system by trypsin treatment.dna synthesis in a broken cellular preparation of chinese hamster cells was enhanced approximately 10-fold by a brief trypsin treatment. alphachymotrypsin also enhanced the synthesis, whereas pronase did not. the trypsin appears to be acting on a component of the nucleus. evidence suggests that the trypsin is not removing protein from the dna, but may be activating the system some other way.19744526218
insulin secretion of the isolated perfused pancreas of the chinese hamster (cricetulus griseus). 19744406592
studies on 1-beta-d-arabinofuranosyl-cytosine (ara-c) resistant mutants of chinese hamster fibroblasts. ii. high resistance to ara-c as a genetic marker for cellular hybridization. 19744366978
effect of quinacrine on survival and dna repair in x-irradiated chinese hamster cells. 19744856778
the frequency and distribution of isolabelling in chinese hamster chromosomes after exposure to x-rays. 19744836308
[h3-uridine incorporation into the nucleolus and the extranucleolar portion of the nucleus in the early periods of the action of actinomycin d on a chinese hamster cell culture]. 19744600720
the response of chinese hamster cells to 252californium neutrons and 14 mev neutrons. 19744474942
mutants of cultured chinese hamster cells deficient in adenine phosphoribosyl transferase. 19744472208
mutations affecting adenine phosphoribosyl transferase activity in chinese hamster cells. 19744370211
the isolation from ribonucleic acid of substituted uridines containing alpha-aminobutyrate moieties derived from methionine.the rna of an established line of chinese hamster cells growing in cell culture contains a small number of uridines substituted at the 3-position with a gamma-linked alpha-aminobutyrate residue. structure has been ascertained by: (a) examination of incorporation of isotopic labels from precursors; (b) degradation with anhydrous hydrazine and comparison of the products with synthetic material or with hydrazinolysis products of known uridines; and (c) comparison of the unknowns as their hydantoin ...197411400439
the influence of 5-bromodeoxyuridine on dna repair in chinese hamster cells exposed to ultraviolet radiation. 19744857591
thermally enhanced radioresponse of cultured chinese hamster cells: inhibition of repair of sublethal damage and enhancement of lethal damage. 197410876605
alterations in nuclear phosphoproteins of a temperature-sensitive chinese hamster cell line exposed to non-permissive conditions. 19744857157
conditional lethal mutants of chinese hamster cells: mutants requiring exogenous carbondioxide for growth. 19744822527
proceedings: effect of anaesthesia on dna synthesis in chinese hamster fibroblasts. 19744451612
the enhancement by caffeine of alkylation-induced cell death, mutations and chromosomal aberrations in chinese hamster cells, as a result of inhibition of post-replication dna repair. 19744362724
effects of actinomycin d, amethopterin, and 5-fluro-2'-deoxyuridine on procentriole formation in chinese hamster fibroblasts in culture. 19744275067
proceedings: cytogenetic investigations on the spermatogonia of the chinese hamster for mutagenicity testing. 19744276609
sub-ribosomal particles of cultured chinese-hamster cells. relationship between rna and protein components. 19744857733
cell cycle and cell protein content of chinese hamster cells grown in culture with daily renewal of medium. 19744131761
[macromolecular syntheses and cell population kinetics during induction of proliferation in stationary cultures of chinese hamster cells]. 19744478035
reversion of a chinese hamster cell auxotrophic mutant.a mutant cell strain derived from a chinese hamster line by mutagenesis with ethylmethane sulfonate requires glycine for growth. in the wild type, glycine synthesis is catalyzed by serine hydroxymethyltransferase (ec cell fractionation by differential centrifugation and isopycnic sucrose gradient analysis reveals that the enzyme activity is found in both the mitochondrial and cytosol fractions. the specific activity in the mitochondrial fraction is about 20 times higher than in the cyt ...19744362629
glycosphingolipids of wild-type and mutant lectin-resistant chinese hamster ovarian cells. 19744857008
uv-induced chromatid aberrations in cultured chinese hamster cells after one, two, or three rounds of dna replication. 19744858326
chinese hamster cells exhibiting a temperature dependent alteration in purine transport. 19744855909
cyclic changes in the cell surface. ii. the effect of cytochalasin b on the surface morphology of synchronized chinese hamster ovary cells.the surface morphology of chinese hamster ovary cells treated with cytochalasin b (cb) has been examined using the scanning electron microscope. the cells respond to treatment with cb by retracting peripheral processes, rounding up, and assuming a smooth or gently convoluted surface. this response occurs within minutes. cells in different stages of the cell cycle all respond in a similar manner. when cb is removed from treated cells by washing with conditioned medium, the cells regain their norm ...19744855904
cyclic changes in the cell surface. i. change in thymidine transport and its inhibition by cytochalasin b in chinese hamster ovary cells.cytochalasin b (cb) shows a marked concentration-dependent inhibition of the incorporation of [(3)h]thymidine into chinese hamster ovary cells. this inhibition was shown to result from an inhibition of thymidine uptake, not from an inhibition of dna synthesis. cells normally acquire the capacity to transport thymidine as they move from the g1 stage of the cell cycle into the s phase. if cb is added to cells while they are in g1, they do not acquire the ability to transport thymidine as they ente ...19744855903
cell cycle-specific changes in histone phosphorylation associated with cell proliferation and chromosome condensation.preparative polyacrylamide gel electrophoresis was used to examine histone phosphorylation in synchronized chinese hamster cells (line cho). results showed that histone f1 phosphorylation, absent in g(1)-arrested and early g(1)-traversing cells, commences 2 h before entry of traversing cells into the s phase. it is concluded that f1 phosphorylation is one of the earliest biochemical events associated with conversion of nonproliferating cells to proliferating cells occurring on old f1 before synt ...19744855902
enzyme activities in extracts of 8-azaguanine-resistant mutants of cultured chinese hamster cells induced by the carcinogen, 7-bromomethylbenz(a)anthracene. 19744842108
the oxygen enhancement ratio and relative biological effectiveness for combined irradiations of chinese hamster cells by neutrons and gamma-rays. 19744544913
effects of caffeine on radiation-induced phenomena associated with cell-cycle traverse of mammalian cells.caffeine induced a state of g(1) arrest when added to an exponentially growing culture of chinese hamster cells (line cho). in addition to its effect on cell-cycle traverse, caffeine ameliorated a number of the responses of cells to ionizing radiation. the duration of the division delay period following x-irradiation of caffeine-treated cells was reduced, and the magnitude of reduction was dependent on caffeine concentration. cells irradiated during the dna synthetic phase in the presence of caf ...19744360269
the temporal replication of ribosomal genes in synchronized chinese hamster cells. 19744856345
the induction of mutations of resistance to an analog of hypoxanthine by ultraviolet radiation in a chinese hamster cell culture. 19744824837
metaphase chromosome aberrations in the chinese hamster liver in vivo after either acute or fractionated 60co irradiation. 197410874935
[kinetics of spermatogenesis in the chinese hamster]. 19744467661
characteristics of an hprt-deficient chinese hamster cell line. 19744462979
chromosomal anomalies induced by the organic phospahte pesticide guthion in chinese hamster cells. 19744448111
[ploidy effect on the radiation reaction of mammalian cells. i. a new tetraploid chinese hamster cell line (author's transl)]. 19744421128
the sex chromosomes of the chinese hamster: constitutive heterochromatin deficient in repetitive dna sequences. 19744135468
biochemical and morphological studies of partially purified chinese hamster chromosomes. 19744133992
identification of interspecific translocation chromosomes in human-chinese hamster hybrid cells.chromosome material of human and chinese hamster origin can be stained differentially in human-chinese hamster translocation chromosomes by use of the giemsa-11 staining technique.197551825
sister chromatid exchange in human chromosomes from normal individuals and patients with ataxia telangiectasia.a new fluorescence plus giemsa staining technique now makes the detection of sister-chromatid exchange (sce) a relatively easy matter in cells containing 5-brdu-substituted dna. the technique has been applied to human cells to examine the distribution of sce between different people and within different chromosomes. the results show: (1) that there were no large differences in the incidence of sce between blood leukocyte chromosomes from male and female adults and newborn, and that similar frequ ...197552431
visualization of nucleolar organizer regions im mammalian chromosomes using silver staining.a simple ammoniacal silver staining procedure, designated ag-as, differentially stains the chromosomal locations of ribosomal dna in certain mammalian species. this was critically demonstrated by ag-as staining of the nucleolus organizer regions in karyotypes of the same species and cell lines used for locating the ribosomal cistrons by dna/rna in situ hybridization. with ag-as, silver stained nors (ag-nors) are visualized as black spherical bodies on yellow-brown chromosome arms. ag-nors were v ...197553131
enterotoxigenic escherichia coli and idiopathic diarrhoea in bangladesh.faecal escherichia coli from bangalee patients with idiopathic diarrhoea were tested in the chinese hamster ovary cell (c.h.o.) assay to detect production of thermolabile enterotoxin (l.t.). c.h.o-positive e. coli produce both l.t. and a thermostable toxin (s.t.). c.h.o.-positive strains were found in 19.2% of all cases and in 70% of the most severely ill patients with non-vibrio cholera. e. coli which produce s.t. alone were identified in a third of the c.h.o.-negative cases. enterotoxigenic e. ...197553601
expression of differentiated functions in hepatoma cell hybrids: ix extinction and reexpression of liver-specific enzymes in rat hepatoma-chinese hamster fibroblast hybrids.most of the hybrid clones derived from a cross of chinese hamster fibroblasts (don) with rat hepatoma cells (faza 967) showed preferential loss of rat chromosomes. two of the hybrid clones retained the rat chromosomes, and both showed extinction of 4 liver-specific enzymes: aldolase b, liver alcohol dehydrogenase, and the inducible enzymes tyrosine aminotransferase and alanine aminotransferase. subcloning of 1 of these hybrids, which contained 2 sets of hepatoma chromosomes and 1 set of hamster ...197517164
diabetogenic effects of n-nitrosomethylurea in the chinese evaluate the role of the glucose residue of the diabetogenic substance streptozotocin, the effect of its aglucone derivate n-nitrosomethylurea was tested in chinese hamsters. at a dose of 50 mg/kg body weight of n-nitrosomethylurea a triphasic blood glucose curve was recorded with an initial hyperglycaemic peak after 3 hours followed by a decrease at 6 hours. after 24 hours and during the following days the values were moderately elevated. there was a high mortality in the diabetic animals, a ...1975125026
rate and time of dna synthesis of individual chinese hamster cells.the duration of dna synthesis of a diploid cell line of chinese hamster fibroblasts was determined in a comparative study by the flm technique, and also by a new technique for measuring the rate of dna synthesis of individual cells. these methods produced comparable results when applied during exponential growth of the cells. the rate of dna synthesis was measured by means of quantitative autoradiography following a short-term incubation of the cells with 5 x 10(-6) m fudr and 10(-5) m 14c-tdr. ...1975126804
simian virus 40 functions required for the establishment and maintenance of malignant transformation.members of the five classes of temperature-sensitive simian virus 40 mutants were tested for their ability to transform chinese hamster lung cells. two criteria for transformation were used: the ability to form clones in medium with low serum concentrations and the ability to overgrow a monolayer. only a mutants failed to transform at the restrictive temperature when subconfluent chinese hamster lung monolayers were used. however, both a and d mutants failed to transform at the restrictive tempe ...1975163374
detection by means of cell fusion of macromolecular synthesis involved in the reconstruction of the nuclear envelope in mitosis.using the cultured chinese hamster cell line don, g1 or s or a mixture of late-s/g2 cells were prepared by release from metaphase arrest. metaphase (m) cells were also obtained by mitotic arrest of log-phase cultures with colcemid and held in metaphase; such m cells remained untreated with any other compound and were termed standard m cells. when interphase (i) cells were fused at ph 8.0 and 37 degrees c with standard cells in the presence of colcemid by means of uv-inactivated sendai virus, bin ...1975163831
cellular adsorption function of the sialoglycoprotein of vesicular stomatitis virus and its neuraminic acid.exposure of vesicular stomatitis (vs) virions to neuraminidase resulted in loss of their ability to agglutinate goose erythrocytes and to attach to l cells concomitant with hydrolysis of sialic acid. these viral adsorptive functions were also destroyed by tryspsinization. sialyl transferase resialylation in vitro of neuraminidase-treated vs virions restored their hamagglutinating and adsorptive functions almost to original levels. erythrocyte and l cell receptors for attachment of vs virions wer ...1975163924
hudrolysis of butyryl derivatives of adenosine cyclic 3':5'-monophosphate by chinese hamster ovary cell extracts and characterization fo the products. 1975164439
mutant hamster cells exhibiting a pleiotropic effect on carbohydrate metabolism.sixty-seven galactose negative (gal minus) clones were established from survivors after treatment of chinese hamster lung (v79) cells with 5-bromodeoxyuridine and black light. the mutational origin of these clonal isolates was inferred on the basis of the previously demonstrated mutagenic action of the combined treatment, persistence of the gal minus phenotype in cell progeny in the absence of selection, conditional lethality of three isolates, interallelic complementation, and assignment of a h ...1975164654
changes in lactate dehydrogenase enzyme pattern in chinese hamster cells infected and transformed with simian virus 40.the lactate dehydrogenase (ldh) isozyme patterns of consecutive passages of chinese hamster embryo cultures were monitored. at early passages the population displayed two ldh bands, m4 and m3h; however, at higher passages the cultures exhibited m2h2, m2h, and m4. when primary cultures of chinese hamster embryo cells were infected with simian virus 40 (sv40), no change in the ldh pattern was observed; however, the total activity of ldh increased. twenty-three of 25 transformed colonies isolated f ...1975167939
the effects of several croton oil constituents on two types of dna repair and cyclic nucleotide levels in mammalian cells in vitro.the purpose of the present study was to determine the effects of two potent tumor-promoting agents on two dna repair mechanisms and cyclic nucleotide levels in mammalian cells. human amnion (av3) cells were treated with low dose levels of either uv of n-acetoxy-acetylaminofluorene. subsequently, dna excision repair as measured by unscheduled dna synthesis was followed in the absence or presence of non-toxic levels of either 12-o-tetradecanoylphorbol-13-acetate (tpa), phorbol-12,13-dibenzoate (pd ...1975168978
site of synthesis of membrane and nonmembrane proteins of vesicular stomatitis virus.upon infection of chinese hamster ovary cells (cho), vesicular stomatitis (vsv) virus synthesizes two membrane proteins (the vsv glycoprotein and the vsv matrix or membrane (m) protein) and three nonmembrane proteins (the vsv nucleocapsid, the viral transcriptase, and an ns protein). we have used the vsv-infected cell as a model system for the study of the site of synthesis of these membrane and nonmembrane proteins. we have isolated vsv mrna from free polyribosomes, membrane-bound polyribosomes ...1975169263
a rapid electrophoretic technique for human and chinese hamster galactokinase. 1975170194
induction of gene mutations and chromosomal aberrations by simian virus 40 in cultured mammalian cells.induction of gene mutations by sv40 was studied in aneuploid human and chinese hamster cells. in chinese hamster cells sv40-induced chromosome aberrations were also studied. sv40 penetrated into the cells of both lines and induced synthesis of the t antigen. the efficiency of infection in chinese hamster cells was tested additionally by their ability to form colonies in medium lacking the serum growth factor. the maximal number of cells with serum growth factor independence was observed on the f ...1975172787
thermolabile t (tumor) antigen from cells transformed by a temperature-sensitive mutant of simian virus 40.partially purified tumor (t) antigen from a strain of chinese hamster lung cells transformed by wild-type simian virus 40 (sv 40) and either of two temperature-sensitive sv 40 mutants has been studied as a dna binding protein. the dna binding activity present in the t-antigen-containing fractions is inhibited by purified hamster anti-t igg but not by equivalent amounts of nonimmune hamster igg. t from either wild-type- or tsc219-transformed cells is relatively stable during heating at 44 degrees ...1975172906
growth of enveloped rna viruses in a line of chinese hamster ovary cells with deficient n-acetylglucosaminyltransferase activity.sindbis and vesicular stomatitis viruses were grown in a line (termed 15b) of chinese hamster ovary (cho) cells that is deficient in a specific udp-n-acetyl-glucosamine:glycoprotein n-acetylglucosaminyltransferase. both viruses replicated normally in the cell line, but the glycoproteins of the released virus migrated faster on sodium didecyl sulfate-polyacrylamide gels than did glycoproteins of virus grown in parent cho cells. digestion of the viral glycoproteins with pronase followed by gel fil ...1975173886
simian virus 40-chinese hamster kidney cell interaction. i. relationship of chromosome changes to transformation.after approximately 20 in vitro passages, chinese hamster kidney (chk) cell cultures transformed upon exposure to different strains of sv 40 can show a diploid modal chromosome number of 22 with chromosome counts exclusively or essentially in the diploid range (20-25). in primary culture and at the 5th-7th subculture, tumors produced in nude mice by such cells can display a diploid modal value of 22 chromosomes. numerical chromosome variations and karyotype abnormalities observed in chk cells tr ...1975174521
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