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Biomedical subjects

S Laskin

Publications and source records attributed to S Laskin.

At least 19 recordsLinked to original sources
PubMed1982

Myelogenous leukemia in rodents inhaling benzene.

Studies during the past five decades have failed to demonstrate myelogenous leukemia in laboratory animals exposed to benzene despite epidemiologic evidence linking such exposure to myelogenous leukemia in man. We report four cases of myeloproliferative disease among rodents exposed to benzene, 6 h a day, 5 days weekly, for life. There was one case of chronic myelogenous leukemia, one of acute myeloblastic leukemia, and one of granulocytic hyperplasia among 40 CD-1 mice exposed to 300 ppm benzene; and one case of chronic myelogenous leukemia among 40 rats exposed to 100 ppm benzene. Although not statistically significant as compared to the respective control groups, the fact that myelogenous leukemia has not been reported in control animals of these two strains is suggestive of a causative role for benzene.

Animals↗
PubMed1982

Gaseous formaldehyde and hydrogen chloride induction of nasal cancer in the rat.

The carcinogenic response to the combined and separate exposures to formaldehyde (HCHO) and hydrochloric acid (HCl) was investigated in male inbred SD rats. The rats were exposed to gaseous HCHO, 14 ppm, and HCl, 10 ppm, in two experiments. In one experiment the gases were premixed at high concentrations before being diluted in the exposure chamber air to maximize the formation of the carcinogen bis(chloromethyl)ether (BCME). In the second experiment exposure was repeated to HCl and HCHO premixed at high concentrations, and not premixed (to minimize BCME formation), as well as to HCHO alone and HCl alone. The second experiment is being reported on at an interim stage. HCHO alone induced squamous carcinomas of the nasal cavity as did the combined exposures to HCHO and HCl. No carcinogenic response was observed with HCl alone. HCHO accounted for most, if not all, of the carcinogenic activity of the mixture of HCHO-HCl.

Animals↗
PubMed1980

Inhalation carcinogenicity of epichlorohydrin in noninbred Sprague-Dawley rats.

Inhalation exposure experiments with the direct-acting alkylating agent epichlorohydrin (ECH) were done on noninbred male Sprague-Dawley rats. Single 6-hour exposure to ECH and follow-up for 14 days showed the median lethal concentration to be about 360 ppm. Further inhalation experiments were done with 6-hour exposure 5 days/week. A short-term 30-exposure regimen with 100 ppm ECH produced malignant squamous cell carcinomas of the nasal cavity in 15 of 140 rats and respiratory tract papillomas in 3 rats. Among 100 rats, lifetime exposure to 30 ppm yielded 1 malignant squamous carcinoma of the nasal cavity plus 1 nasal papilloma. No nasal or respiratory tract tumors were produced by lifetime exposure of 100 rats to 10 ppm. As controls, 100 air-treated and 50 untreated rats were used. A dose-rate effect was observed for ECH inasmuch as 30-day exposure to 100 ppm (3,000 ppm-days) produced 15 cancers in comparison to the 1 cancer from the lifetime exposure to 30 ppm (8,700 ppm-days) and no cancers from lifetime exposure to 10 ppm (2,500 ppm-days).

Animals↗
PubMed1980

Inhalation carcinogenesis by dimethylcarbamoyl chloride in Syrian golden hamsters.

The comparative carcinogenicity of dimethylcarbamoyl chloride (DMCC) was studies in male, Syrian Golden Hamsters by inhalation. Hamsters were exposed to 1ppm and the exposure periods were 6 hours per day, 5 days per week for the lifetime of the animals. Fifty-one percent of the hamsters developed carcinomas of the nasal tract. Morphologically, all of these tumors were classified as squamous cell carcinomas. In comparing the response of rats and hamsters at 1 ppm DMCC, the rat seems to show increased sensitivity and the percentage of tumor yield is almost doubled, with the tumors appearing much earlier in rats than in hamsters. However, the remarkable tumor yield in both species indicates the potent carcinogenic effects of DMCC.

Animals↗
PubMed1978

Hematotoxicity of inhaled benzene to Sprague-Dawley rats and AKR mice at 300 ppm.

Sprague-Dawley rats and AKR/J mice were exposed to 300 ppm benzene vapor for 6 h/d, 5 d/wk, for life. Rats exhibited lymphocytopenia, mild anemia, and moderately decreased survival. Mice showed severe lymphocytopenia and anemia accompanied by granulocytosis and reticulocytosis. Treated mice also showed significantly decreased survival and weight gain. No indications of a leukemic or preleukemic response were observed in either species.

Animals↗
PubMed1978

The Laskin aerosol generator.

This paper describes construction details and operating characteristics of a nebulizer developed by Sidney Laskin and used over a period of 30 yr in various laboratories to generate respirable aerosols for whole-animal inhalation exposure studies. Under the proper operating conditions, the device is capable of producing nearly monodisperse aerosols in the respirable size range (1.5 micron volume median diameter with a geometric standard deviation of 1.1) for long periods of time

Aerosols↗
PubMed1977

An extraction method for determination of benzene in tissue by gas chromatography.

An extraction procedure has been developed for the determination of benzene by gas chromatography in tissues following inhalation. Results are reproducible using very small quanities of sample (0.05 g for tissue and 0.02 ml for blood). The procedure has been applied to the analysis of blood and tissue of A.K.R. mice following a single exposure to levels similar to those that may be found in industrial hygiene atmospheres.

Animals↗
PubMed1975

Inhalation carcinogenicity of alpha halo ethers. I. The acute inhalation toxicity of chloromethyl methyl ether and bis(chloromethyl)ether.

A range of acute studies were performed with chloromethyl methyl either (CMME) and bis(chloromethyl)ether (BCME), including 14-day LC50's following single seven-hour inhalation exposures. The LC50's for CMME were 55 ppm for rats and 65 ppm for hamsters. The LC50's for BCME were 7 ppm for both species. All animals showed characteristic changes of acute irritation of the respiratory tract manifested by congestion, edema, and hemorrhage. Severe shortening of life span was seen in 30-day exposures of rats to CMME and in all studies with BCME. Incidences of mucosal changes, including atypia, were generally increased in a dose-related manner in both species. The carcinogenicity of BCME in these range finding experiments was demonstrated by a skin cancer in a rat after three exposures and a nasal tumor in a hamster after one exposure to 1 ppm BCME.

Animals↗
PubMed1975

Inhalation carcinogenicity of alpha halo ethers. II. Chronic inhalation studies with chloromethyl methyl ether.

Rats and hamsters were exposed to 1 ppm of chloromethyl methyl ether six hours per day, five days per week, throughout their lifetime. Mortality and weight gain of the exposed animals paralleled that of the control animals. Malignant tumors of the respiratory tract were found in two rats. These were a squamous cell carcinoma of the lung with blood vessel invasion and an esthesloneuroepithelioma originating in the olfactory epithelium and invading the forebrain. One hamster was found to have an adenocarcinoma of the lung and another, a squamous papilloma of the trachea. A single exposed rat had a pituitary tumor of primitive cell type that may well have been coincidental.

Adenocarcinoma↗
PubMed1975

Inhalation carcinogenicity of alpha halo ethers. III. Lifetime and limited period inhalation studies with bis(chloromethyl)ether at 0.1 ppm.

Rats and hamsters were exposed to 0.1 ppm bis(chloromethyl)ether (BCME) six hours per day, five days per week throughout their lifetime. Additional groups of rats were given 10, 20, 40, 60, 80, and 100 exposures to 0.1 ppm BCME and then held until death. Forty cancers originating in the respiratory tract were found in the 200 rats involved in these studies. These included 14 cancers of the lung and 26 cancers of the nasal cavity. They occurred in dose-related fashion. A single undifferentiated carcinoma of the lung was seen in a hamster.

Animals↗