Publications

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rna synthesis in chinese hamster cells. i. differential synthetic rate for ribosomal rna in early and late interphase.the incorporation of methionine-methyl-(14)c into 18s ribosomal rna of cultured chinese hamster ovary cells in early and late interphase has been determined by zone-sedimentation analysis of phenol-extracted rna preparations. synchronized cell cultures were prepared for these studies by thymidine treatment and by mechanical selection of mitotic cells. the specific activity of 18s rna labeled in late interphase was found to be 1.1-1.2 times that of 18s rna labeled in early interphase. upon correc ...19685645548
separation of isolated chinese hamster metaphase chromosomes into three size-groups. 19684230571
failure of chinese hamster cells to repair sub-lethal damage when x-irradiated in the plateau phase of growth. 19685641124
cyclic changes in enzyme activity in synchronized mammalian cell cultures.activity of the enzymes glucose-6-phosphate dehydrogenase and lactate dehydrogenase increases intermittently in synchronized cultures of chinese hamster cells. during g(1) phase (3 hours after mitosis), midway through s phase (7 hours after mitosis) and again in late s phase (10 hours after mitosis), rapid increases in activity were observed and correlated with a net increase in cell size and total protein. the evidence suggests that this is a general phenomenon which affects a whole population ...19685716136
chinese hamster cell monolayer cultures. ii. x-ray sensitivity and sensitization by 5-bromodeoxycytidine in the exponential and plateau periods of growth. 19685761386
chinese hamster cell monolayer cultures. i. changes in cell dynamics and modifications of the cell cycle with the period of growth. 19685761385
the combined effect of hydroxyurea and x-rays on chinese hamster cells in vitro. 19685641513
cysteamine: differential x-ray protective effect on chinese hamster cells during the cell cycle.cysteamine present during x-irradiation protects synchronized chinese hamster cells in culture against lethal damage at all stages of the cell cycle. the effect is greatest for cells irradiated at sensitive stages such as g(1) and least for resistant cells; for example, late s (dose-modifying factors 4.2 and 2.7, respectively). the effect of 50 millimolar cysteamine is to render almost invariant the normally variant x-ray age response for lethality. this suggests that there are two components of ...19685634666
growth-promoting effect of lysolecithin on chinese hamster cells in vitro. 19685639135
synchronization of chinese hamster ovary cells in a tissue culture pilot plant. la-3848-ms. 19685302794
characterization of chinese hamster ovary histone fractions. la-3848-ms. 19685302792
[action of cysteamine on the chromosomes of chinese hamster fibroblasts in culture]. 19684967251
[effects of decrease of temperature on the mitotic activity of chinese hamster cultures]. 19685761258
asynchrony of dna replication and mitotic spiralization along heterochromatic portions of chinese hamster chromosomes. 19685662571
chromosomal changes in the chinese hamster thyroid following x-irradiation in vivo. 19685303350
the chromosomes of forty-two primary rous sarcomas of the chinese hamster. 19684298639
observations on the propagation of chinese hamsters. 19684231922
radioprotective effect of rat kangaroo haematopoietic cells on x-irradiated mice and chinese hamsters. 19694890684
cell sorting: automated separation of mammalian cells as a function of intracellular fluorescence.a system for high-speed sorting of fluorescent cells was able to sort mouse spleen cells from chinese hamster ovarian cells after development of fluorochromasia. highly fluorescent fractions separated after similar treatment from mouse spleen cells immunized to sheep erythrocytes were enriched in antibody-producing cells by factors of 4 to 10.19694898615
ribonucleic acid synthesis of vesicular stomatitis virus. i. species of ribonucleic acid found in chinese hamster ovary cells infected with plaque-forming and defective particles.plaque-forming b particles of vesicular stomatitis virus (vsv) induce the synthesis of virus-specific ribonucleic acid (rna) in chinese hamster ovary cells, whereas defective t particles do not. infection with low input multiplicities of b results in the formation of four species of rna. during infection with high multiplicities, rna synthesis begins with mainly these four species of rna but gradually shifts to a new pattern of rna synthesis involving five other species of rna. the change can al ...19694308915
presence of viral genome in chinese hamster embryonic cell transformed in vitro with bryan strain of rous sarcoma virus (b-rsv). 19694314438
isolated mammalian metaphase chromosomes. ii. fractionated chromosomes of mouse and chinese hamster cells. 19695391786
mutation and inactivation of cultured mammalian cells exposed to beams of accelerated heavy ions. ii. chinese hamster v79 cells.inactivation and mutation to thioguanine-resistance of v79 hamster cells were studied after irradiation with accelerated helium, boron or nitrogen ions covering a range of linear energy transfer from 28 to 470 kev micrometers-1. for all radiation qualities a dose-dependent increase in mutant frequency was found for doses giving surviving fractions greater than about 0.20. the effectiveness per unit dose for both inactivation and mutation induction increased with the linear energy transfer of the ...1969315388
chromosome aberrations and other effects produced by 90sr-90y in chinese hamsters. 19695308578
effects on the endocrine pancreas in chinese hamsters fed zinc deficient diets. 19694906988
pancreatic islet morphology in diabetic chinese hamsters. a light and electron microscopic study. 19694895643
monogamous mating of chinese hamsters. anl-7635. 19695310840
cytogenetic and other effects of 144ce in chinese hamsters. lf-41. 19695310176
spontaneous lesions in a colony of chinese hamsters. 19694308318
temporal coordination of dna replication with enzyme synthesis in diploid and heteroploid cells.the rate of dna synthesis in the s phase of growth of synchronized diploid chinese hamster cells shows two maximums, while in heteroploid hamster cells the dna replication rate is constant. in diploid cells a reciprocal relationship exists between maximum dna synthetic rates and maximum lactate dyhydrogenase and thymidine kinase enzyme levels. enzyme activity in heteroploid cells increases continuously through the cell cycle with no evidence of oscillations. it seems possible that these differen ...196917655055
on the duplication of ribosomal rna cistrons in chinese hamster cells. 19695392317
the metaphase chromosomes of chinese hamster liver cells following partial hepatectomy. 19695370786
polyploidy induced by x rays during the generation cycle of synchronized chinese hamster cells. anl-7635. 19695310801
cytological studies on cysteamine protected chinese hamster cells in vitro. anl-7635. 19695310800
ultraviolet light-induced division delay in synchronized chinese hamster cells. anl-7635. 19695310798
the effect of x rays on the uptake of 3h-leucine in synchronized chinese hamster cells. anl-7635. 19695310797
cycloheximide- and radiation-induced division delay in synchronized chinese hamster cells. anl-7635. 19695310796
sensitization of chinese hamster cells to x-rays by n-ethylmaleimide. anl-7635. 19695310795
recovery from sublethal damage induced by x irradiation in cysteamine protected chinese hamster cells. anl-7635. 19695310792
the cell cycle distribution of chinese hamster cells in stationary phase cultures. anl-7635. 19695310791
genetics of somatic mammalian cells. x. complementation analysis of glycine-requiring mutants.complementation analysis at the single gene level has been carried out on 13 different, recessive, glycine-requiring mutants produced by action of mutagenic agents on the cho-k1 chinese hamster cell. the mutants form four different complementation classes indicating that at least four separate genes can produce a growth requirement for glycine. the four classes of mutants can be distinguished biochemically as well as genetically. existence of these four mutant classes appears to explain the prep ...19695271752
[study of sensitivity of inhibitors of rna and protein synthesis during the individual stages of the mitotic cycle in cell cultures of the chinese hamster]. 19694246154
synchronized mammalian cell cultures. 3. variation of ribonucleotide reductase activity during the replication cycle of chinese hamster fibroblasts. 19695408612
radiosensitivity of mammalian cells. 3. effect of suboptimal growth temperatures on recovery from radiation-induced division delay.we investigated the effect of suboptimal growth temperatures on recovery from radiation-induced division delay in chinese hamster cells. it was found that no recovery occurred during the time that either log-phase or synchronized populations were incubated at 4 degrees c and that injury sustained at low dose rates was cumulative over a period of 6.2 hr at low temperature. postirradiation conditions influencing recovery from the induced division delay period are different from those affecting sur ...19695389451
temporal order in mammalian cells. i. the periodic synthesis of lactate dehydrogenase in the cell cycle.chinese hamster cells were synchronized by the colcemid-selection system. in cells with a division cycle time of 11.5-12 hr, the activity of the enzyme lactate dehydrogenase (ldh) underwent marked oscillations with a 3.5-hr period. precipitation of labeled ldh enzyme with specific antibody indicated that the enzyme activity changes were the result of intermittent enzyme synthesis and relatively constant degradation. inhibition of normal dna replication with 4 mm of thymidine, while reducing the ...19695344146
metabolism and toxicity of 241am in the chinese hamster. lf-41. 19695310179
60co-induced metaphase chromosome aberrations in chinese hamster liver cells. lf-41. 19695310175
effects of hypertonic sucrose on the radiosensitivity of chinese hamster fibroblasts. 19695345342
x-ray induction of chromatid exchanges in mitotic and g1 chinese hamster cells pretreated with colcemid. 19695810929
sensitivity of synchronized chinese hamster cells to ultraviolet light.the age response for lethality of chinese hamster cells to ultraviolet light shows that they are resistant in g(1), sensitive as they move into and through the s phase and resistant again in g(2) and mitosis. survival curves determined at different times in the cycle reveal that mitotic cells are the most resistant fraction, much more resistant than s cells, and more resistant than either g(1) or g(2) cells. the extent to which the age response is ilfluenced by nucleic acid and protein synthesis ...19695807224
x-rays and nitrogen mustard: independent action in chinese hamster cells.we have studied the combined effects of x-irradiation and nitrogen mustard treatment on the colony-forming ability of chinese hamster cells. in contrast to x-irradiation, nitrogen mustard acting by itself yields an exponential dose-effect relationship. moreover, whether delivered in immediate sequence or after varying intervals, nitrogen mustard treatment does not affect radiation survival and vice versa. these results, plus the lack of any indication of the repair of sublethal nitrogen mustard ...19695807220
cell killing by actinomycin d in relation to the growth cycle of chinese hamster cells.using chinese hamster cells in culture, we have measured the effectiveness of actinomycin d to suppress division as a function of the position, or age, of a cell in its growth cycle. cells were first exposed to millimolar concentrations of hydroxyurea in order to produce a synchronized population just before the onset of dna synthesis. thereafter, the survival response after 30 min exposures to actinomycin d was measured. cells become resistant as they enter the s phase and then sensitive again ...19695792326
modesl of growth in mammalian cells.the increase of cell volume as a function of time was studied throughout the generation cycle in synchronous cultures of chinese hamster cells using a coulter aperture and a multichannel analyzer calibrated against known cell volumes. the experimental results were compared to a mathematical model of cell volume increase which considered the effect of the distribution of individual cell generation times on the progress of the population. several modes of volume increase, including linear and expo ...19694898382
the effect of excess methionine on the pancreas. a light and electron microscopic study in the chinese hamster with particular reference to degenerative changes. 19694896281
single strand interruptions in dna and the effects of caffeine in chinese hamster cells irradiated with ultraviolet light. 19695816421
rna synthesis in chinese hamster cells. ii. increase in rate of rna synthesis during g1.cultures of mitotic chinese hamster cells, prepared by mechanical selection, were pulse-labeled with methionine-methyl-(14)c or with uridine-(3)h at different stages in the life cycle. the rate of (14)c incorporation into 18s rna was measured, as was the rate of uridine-(3)h incorporation into total rna for both monolayer and suspension cultures. the rate of incorporation increased continuously throughout interphase in a fashion inconsistent with a gene-dosage effect upon rna synthesis.19695795885
fertilization of chinese hamster eggs in vitro. 19695793469
protection by cysteamine against lethal x-ray damage during the cell cycle of chinese hamster cells. 19695789038
mammalian cell genetics. i. selection and characterization of mutations auxotrophic for l-glutamine or resistant to 8-azaguanine in chinese hamster cells in vitro. 19695392645
the effect of histones, poly-l-lysine and dna on the mitotic activity of chinese hamster fibroblasts. 19695388934
isolation and characterization of thymidine transport mutants of chinese hamster cells. 19694182358
post-irradiation properties of cultured chinese hamster cells exposed to ultraviolet light. 19695771800
vinblastine-induced chromosomal alterations in cultured chinese hamster cells. 19695360881
complementation analysis on virus-fused chinese hamster cells with nutritional markers.cell fusion experiments have been carried out with chinese hamster cell mutants with different nutritional growth requirements. conditions have been devised in which approximately 1 to 2 percent of the cell population remaining after fusion are fused, hybrid cells. the all-or-none nature of the genetic markers employed and the extremely low reversion rates insure that no contamination of the hybrid population with parental forms occurs. hybrids between glycine- and hypoxanthine-requiring mutants ...19695813351
effect of mannitol mustard (nsc-9698) on nuclear dna content and birefringence of hela and chinese hamster cells. 19695799416
segregation of chromosomal dna in chinese hamster fibroblasts in vitro. 19695780787
observations on nuclear rotation and oscillation in chinese hamster germinal cells in vitro. 19694888994
low molecular weight methylated ribonucleic acid species from chinese hamster ovary cells. i. isolation and characterization. 19695781009
a correlation between division delay and loss of colony-forming ability in chinese hamster cells irradiated in vitro. 19695305083
[particular nutritive need of chinese hamster cells transformed in vitro by adenovirus 12]. 19694975884
chromosomal nondisjunction: the action of colcemid on chinese hamster cells in vitro. 19695798031
the oxygen effect and x-ray sensitivity in synchronously dividing cultures of chinese hamster cells. 19695762918
chromosome breakage induced in vivo by a carcinogenic hydrocarbon in bone marrow cells of the chinese hamster. 19695399201
autoradiographic study on the synthesis of nuclear proteins. vi. the data on the turnover rate of nuclear proteins and formation of the protein component in chromosomes of chinese hamster cells cultured in vitro. 19695392209
late-replicating y chromosome in spermatogonia of the chinese hamster (cricetulus griseus). 19695381336
morphologic effects of ethionine on the pancreas of the chinese hamster. a light and electron microscopic study of degenerative changes. 19695350754
chronology of chromosome reduplication in chinese hamster cells incubated at low temperature. 19695345641
late-replicating y chromosome in spermatogonia of the chinese hamster (cricetulus griseus). 19695344998
progession of viable and non-viable synchronized chinese hamster cells into the s phase after x-irradiation in mitosis or the s phase. 19695308936
dna repair in chinese hamster cells of different sensitivities to ultra-violet light. 19695308017
sites of nucleolus production in cultured chinese hamster cells.chinese hamster cell strains in the early passages in culture display wide variation in number of nucleolus-like bodies per cell, though such strains are characteristically euploid. a variety of criteria indicate that the nucleolus-like bodies are true nucleoli. their azure b- and fast green-staining properties indicate the presence of rna and protein; they have typical nucleolar fine structure, including both fibrous and granular components; radioautography reveals that their patterns of uptake ...19694177660
a comparison of the modes of inheritance of diabetes in the chinese hamster and the kk mouse. 19705432352
genetics of somatic mammalian cells: linkage studies with human-chinese hamster cell hybrids. 19705473978
[chinese hamster as a model in diabetes research]. 19705512321
preferential loss of kangaroo chromosomes in hybrids between chinese hamster and kangaroo-rat somatic cells. 19705531375
studies of dna-induced heritable alteration of mammalian cells.an intercellular interaction between mouse ehrlich ascites tumor and non-malignant chinese hamster cells occurred when these were co-cultured. that the intercellular processes which formed had emanated from the ea cells was revealed by immunofluoroscopy using anti-ea antiserum, and by direct microscopic examination. a passage of dna from the ea to the ch cells was also observed. on long-term co-culture, new cell forms arose which were isolated, cloned, and propagated. they showed a ch karyotype ...19704995321
replication of repetitious dna and the s period.the renaturation kinetics of labeled dna derived from synchronized chinese hamster cells indicate that the three classes of repetitious dna replicate uniformly throughout the s period, and that a piece of repetitious dna may occur at or near the beginning of each replicon. studies with mouse-cell dna suggest that mouse satellite dna replicates when euchromatin replicates.19705272325
x-ray mutagenesis of cultured chinese hamster cells. 19704908375
isolation and characterization of hybrids between mouse and chinese hamster cell lines. 19704322072
changes in deoxyribonucleic acid synthesis regulation in chinese hamster cells infected with simian virus 40.infection of primary or secondary cultures of chinese hamster embryo cells with simian virus 40 at a multiplicity of 20 to 50 induced synthesis of the virus-specific intranuclear t antigen in 80 to 90% of the cells within 48 to 72 hr. in the infected cultures, 30 to 50% more cells were recruited into deoxyribonucleic acid (dna) synthesis than in the controls, whether or not the cultures were confluent. the newly synthesized dna was mostly cellular, since little virus was produced (as shown by va ...19704322080
carcinogenic and noncarcinogenic polycyclic hydrocarbons in neurospora crassa and chinese hamster cells: their photodynamic effects. 19704193459
chromosome pulverization in virus-induced heterokaryons of mammalian cells from different species.the phenomena of cell fusion and chromosome pulverization after inoculation with uv-inactivated sendai virus were studied in mixed suspensions of cell lines from different mammalian species. two cell combinations were used: the chinese hamster cell line (don) and rpmi 8226 (simpson) cell line of human hematopoietic origin,and the don and llc-mk2 (mk) cell lines, the latter derived from monkey kidney cells. each of the 3 cell lines had a high cell-fusion capacity when infected with the virus in h ...197018605421
survival of synchronized chinese hamster cells following freezing in liquid nitrogen. 19705530921
the relation of protein synthesis to radiation-induced division delay in chinese hamster cells. 19705530793
[functional morphology of the chromosomes of cultivated mammalian cells. iv. nucleolus-organizing region of the x-chromosomes of the chinese hamster in long-term cultures of somatic cells]. 19705512958
regulation of initiation of dna synthesis in chinese hamster cells : ii. induction of dna synthesis and cell division by isoleucine and glutamine in g(1)-arrested cells in suspension culture.suspension cultures of chinese hamster cells (line cho), which had stopped dividing and were arrested in g(1) following growth to high cell concentrations in f-10 medium, could be induced to reinitiate dna synthesis and to divide in synchrony upon addition of the appropriate amounts of isoleucine and glutamine. both amino acids were required to initiate resumption of cell-cycle traverse. deficiencies in other amino acids contained in f-10 medium did not result in accumulation of cells in g(1), i ...197019866743
somatic cell hybridization: pattern of chromosome replication in viable chinese hamster x armenian hamster hybrids. 19705531479
uv-absorption and quinacrine mustard fluorescence patterns for chromosome aberration study in chinese hamster. 19705496280
actinomycin d and radiation fractionation studies in asynchronous and synchronized chinese hamster cells. 19705490498
separation of nuclei representing different phases of the growth cycle from unsynchronized mammalian cell cultures.nuclei have been isolated from unsynchronized cultures of chinese hamster fibroblasts after varying intervals of growth following the incorporation of thymidine (-3)h for 20 min. these nuclei were fractionated by unit gravity sedimentation in a stabilizing density gradient of sucrose, and fractions were analyzed for the concentration of nuclei, dna, and radioactivity. a more rapidly sedimenting population of nuclei in the g(2) phase of the cell cycle was separated from a group of nuclei in the g ...19705513550
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