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V F Garry

Publications and source records attributed to V F Garry.

At least 37 records · Page 2Linked to original sources
PubMed1984

Serum- and plasma-dependent variations of benzo(a)pyrene-induced sister chromatid exchange in human lymphocytes.

Sister chromatid exchange (SCE) is frequently used to assess the potential mutagenicity of chemical agents to human beings. We demonstrate here that levels of SCE induced by benzo(a)pyrene (BP) in the widely used blood lymphocyte assay are influenced by serum and plasma supplements. Sister chromatid exchange induction by BP was greatest when using fetal calf serum (FCS), intermediate with newborn calf serum (NCS), and lowest with autologous human plasma (AHP). This new finding adds to a growing list of factors capable of modulating the SCE response and underscores the need for researchers to consider serum and plasma supplements in the standardization of the SCE approach in human mutagen assessments. The data also demonstrate the potential of SCE to aid in the study of serum factors which modify the mutagen sensitivity of human cells towards environmental carcinogens.

Animals↗
PubMed1983

Colony transformation in C3H 10T1/2 cells: stepwise development of neoplastic change in vitro.

This report demonstrates that low passage C3H 10T1/2 cells treated with the carcinogens benzo(a)pyrene or diepoxybutane are transformed morphologically as colonies in as little as 14 d after carcinogen treatment. A transforming dose-response curve is achieved but the frequency of transformation is less than half the expected for 38 d foci, compared on the basis of percent transformants per cell plated. Anchorage-independent cell growth, plating efficiency, doubling time, cell density, and modal chromosomal number were examined from transformed colonies and foci. The data from colony transformants show progressive alteration of these in vitro expressions of neoplastic character with continued subcultivation, consistent with the multistep hypothesis of carcinogenesis. Early in vivo data obtained from one colony-derived transformed cell line show tumorigenesis in irradiated mice within 13 wk of implantation. With continued in vivo passage, tumors were observed in 4 to 6 wk.

Animals↗
PubMed1982

Effect of hypoxia on carbon tetrachloride hepatotoxicity.

The effect of hypoxia on carbon tetrachloride-induced hepatotoxicity was studied. Male rats were exposed to carbon tetrachloride for 2 hr in the presence of differing oxygen concentrations. Serum glutamate-pyruvate transaminase (SGPT) activities were measured 24 hr after the end of the exposure. Exposure of rats to 5000 ppm carbon tetrachloride in the presence of 100, 21, 12, or 6% oxygen resulted in SGPT activities of 489, 420, 3768, and 1788 I.U./l respectively. Exposure of rats to air and 0, 1250, 2500, 5000, or 7500 ppm carbon tetrachloride gave SGPT activities of 35, 32, 69, 420, and 2188 I.U./l respectively; when 12% oxygen was used, the corresponding SGPT activities were 32, 665, 691, 3768, and 4200 I.U./l respectively. Exposure of rats to hypoxia produced histopathologically detectable condensation of hepatic cytoplasmic material, and exposure to 5000 ppm carbon tetrachloride in the presence of air produced mild centrilobular necrosis, which was much more severe when rats were exposed to 5000 pm carbon tetrachloride in the presence of 12% oxygen. Hepatic microsomal conjugated diene concentrations were increased by hypoxia and by exposure to carbon tetrachloride, but no synergistic interaction was observed. Hepatic microsomal cytochrome P-450 concentrations were decreased after exposure to carbon tetrachloride, but were the same after exposure to carbon tetrachloride and 12 or 21% oxygen. Hepatic carbon tetrachloride concentrations were the same in rats exposed to carbon tetrachloride in the presence of 12 or 21% oxygen; hepatic chloroform concentrations were higher in rats exposed to carbon tetrachloride in the presence of air than in the presence of 12% oxygen. The covalent binding of [14C]carbon tetrachloride metabolites to hepatic microsomal lipids and proteins was increased markedly by hypoxia as compared with normoxia. The covalent binding of metabolites of carbon tetrachloride to cellular macromolecules may play a role in the potentiation of carbon tetrachloride toxicity by hypoxia.

Alanine Transaminase↗
PubMed1982

Differential induction of sister chromatid exchange by chemical carcinogens in lymphocytes cultured from patients with solid tumors.

Three carcinogens with different requirements for activation were used to generate sister chromatid exchange (SCE) in cultured lymphocytes from 22 untreated patients with solid tumors. These data were compared to SCEs produced by incubating lymphocytes, from 44 normal persons, with the same carcinogens. In vitro treatments with butadiene epoxide (0.125 micrograms/ml) show no significant differences in the SCEs generated. However, in vitro treatment with mitomycin-C (0.04 micrograms/ml) did induce significant differences (p less than 0.05) in the distribution of the SCE scores. Treatment of the cultured cells with benzo(a)pyrene (10 micrograms/ml), a carcinogen requiring extensive metabolic activation, significantly (p less than 0.001) altered the distribution of the SCEs generated in vitro. The SCE data suggest that metabolic activities play an important role in the processing of carcinogens in solid tumor patients.

Adolescent↗
PubMed1982

Ethylene oxide induced sister chromatid exchange in human lymphocytes using a membrane dosimetry system.

In an earlier study, we demonstrated that human exposure to ethylene oxide (EO) during sterilization procedures was associated with increased sister chromatid exchanges (SCE) in cultured peripheral blood. To study further toxic and mutagenic properties of EO in vitro, we devised a membrane dosimetry system which can be used to expose lymphocytes in peripheral blood to specified amounts of EO. The system consists of an exposure chamber, cell culture dishes to which are applied plastic membranes of varying diameters and an infrared analyzer used to monitor ambient EO concentrations in the system. Aliquots of EO-exposed media were subjected to gas chromatography for quantitation. Our preliminary analyses of the cultured cells indicate that the membrane dosimetry system we developed is capable of reproducibly delivering quantities of EO to target cells. Elevated SCEs were observed at as little as 10 micrograms/ml (in media) during a 20-min exposure period. A significant dose-response relationship between SCE and EO dose was recorded up to 35 micrograms/ml, the highest dose tested. Lymphocytes at 35 micrograms/ml showed a fourfold increase in SCE compared to control cultures. We conclude that the membrane dosimetry system provides a reproducible method to investigate EO mutagenesis in human cells in vitro and may prove applicable to a wide range of mutagenic gases.

Chromatography, Gas↗
PubMed1979

Ethylene oxide: evidence of human chromosomal effects.

Ethylene oxide is a known mutagen as indicated by short-term testing in vitro and in vivo. Occupational exposure can occur during ethylene oxide gas sterilization of materials for hospital and other use. To study the problem in a hospital sterilization facility where occupational exposure was suspected, epidemiologic, analytic and bioassay tools were employed. All persons whose work activities involved some aspect of the sterilization process were considered exposed to the gas. Within this group of symptomatic and asymptomatic individuals, chronic and incidental exposure was documented by clinical history. Sister chromatid exchanges were studied in lymphocytes cultured from exposed individuals as well as comparable controls. Four chronically exposed persons who reported upper respiratory and neurologic symptoms were studied in some detail. This group showed significantly increased sister chromatid exchange at three weeks and again at eight weeks after the last known exposure. Another group of eight persons with fewer complaints studied as late as the ninth week showed significantly increased exchanges. Incidental exposure may also increase sister chromatid exchange. The measured maximum concentration of ethylene oxide in the sterilizer room was 36 ppm (within standards set by the Occupational Safety and Health Administration).

Chromosome Aberrations↗
PubMed1978

Histological and cytological technique for the quantitation of cultured human bone-marrow cells:formation of aggregates.

A bone-marrow culture system is described that provides a simple, quantitative and rapid assessment of marrow bone cells in vitro. Aggregation of bone-marrow cells, an in vitro phenomenon, occurs within 24 hr of culture and is observed utilizing Millipore filters. Daily quantitation shows both an increase in the number and a change in the morphology of these aggregates. The maximum number of aggregates is achieved on the 2nd or 3rd day of incubation. Histologically, aggregates are composed of myeloid, mononuclear and mesenchymal fibroblastic cells. Mesenchymal cells form a matrix for apposed mononuclear and myeloid cells. Scanning electron micrographs show intimate cell contact and spreading by the marrow cells. Fluctuation of the absolute numbers of various cell types are observed. The system can be utilized for long-term culture of bone marrow.

Bone Marrow Cells↗