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Biomedical subjects

E B Sansone

Publications and source records attributed to E B Sansone.

At least 55 records · Page 3Linked to original sources
PubMed1981

Design and testing of a biocontainment system for chemical carcinogens.

A biocontainment facility was built for studies in which the chemical carcinogen N-methyl-N-nitrosourea (MNU) was instilled intrarectally in guinea pigs. The system operated by constant flow of uncontaminated air into carcinogen-contaminated animal isolation chambers and filtration through a high-efficiency particulate air (HEPA) filter prior to release into the environment. The facility was tested for efficiency of carcinogen containment by substituting for the MNU a similar concentration of a fluorescent tracer, sodium fluorescein, under standard operating procedures for carcinogen administration to guinea pigs. Wipe samples from the floor, isolation chambers, animal handlers and clothing, and intake and exhaust air samples were analyzed for fluorescein before and after intrarectal instillation of the tracer. The recovery of very low concentrations of total and respirable suspended fluorescein from sampling points within the facility and the absence of detectable fluorescein in the air downstream from the HEPA filter indicated that the facility provided adequate protection against contamination of personnel or the environment.

Animals↗
PubMed1981

Formaldehyde degradation by catalytic oxidation.

Formaldehyde used for the disinfection of a laminar-flow biological safety cabinet was oxidatively degraded by using a catalyst. This technique reduced the formaldehyde concentration in the cabinet from about 5,000 to about 45 mg/m3 in 8 h. This technique should prove useful in other applications.

Catalysis↗
PubMed1981

Penetration of rat skin by N-nitrosodiethanolamine and N-nitrosomorpholine.

N-Nitrosomorpholine (NMOR) and N-nitrosodiethanolamine (NDELA) were painted on the clipped upper dorsal skin of male F344 rats. NDELA was applied undiluted, dissolved in water, and dissolved in cutting oil; NMOR was applied dissolved in water and in ethyl acetate. Aqueous solutions of the nitrosamines were used for gavage. Rats were housed individually. Blood and urine samples were analyzed for nitrosamines by chromatography combined with a Thermal Energy Analyzer. Maximum penetration of NMOR was approximately equal to 34% 2 hours after application of 5 mg to the skin or by gavage; less than 1% appeared in the urine in 24 hours. Skin painting with NDELA in water (20 mg/100 microliters) and in cutting oil (25 mg/25 microliters) yielded small concentrations of NDELA (always < 25 micrograms/ml blood). When 50 mg of undiluted NDELA was painted on the skin, 130 to 220 micrograms/ml of blood was recovered after 1 hour. Administering 50 mg NDELA in water by gavage yielded similar blood concentrations. Maximum skin penetration observed with NDELA was 78% 1 hour after application of 50 mg. From 20 to 30% of the NDELA applied undiluted and by gavage appeared in the urine in 24 hours. Although animals and humans differ, skin exposure to NMOR or NDELA represents a risk due to absorption.

Administration, Topical↗
PubMed1980

The permeability of protective clothing materials to benzene vapor.

The permeability coefficient of benzene vapor in air was calculated from experimentally measured values of solubility coefficient and diffusion coefficient for natural rubber, nitrile, neoprene, natural rubber plus neoprene, butyl rubber, polyvinyl chloride and polyethylene membranes. The permeability coefficient for natural rubber at room temperature (approximately 23 degrees C) was 4.2 x 10(-10) cm2/sec when the concentration of benzene in air was 10 ppm. This means that a worker (1.8 m2 surface area) completely clothed in a 0.0254 cm (10 mil) natural rubber suit would be exposed via the skin to 0.3 microgram benzene in an 8-hour shift if the benzene concentration were 10 ppm. In the same time period and with the same benzene concentration the worker would inhale 1600 microgram benzene if his tidal volume were 700 cm3, his breathing rate were 15 min-1, and he was wearing a respiratory with a protection factor of 100. Permeability coefficients for other vapor-membrane systems available in the literature suggest that exposure to vapors penetrating protective garments are in general negligible when compared with inhalation exposures for low vapor concentrations.

Air Pollutants, Occupational↗
PubMed1980

The penetration of rat skin by some nitrosamines of environmental importance.

N-Nitrosomorpholine (NMOR) and N-nitrosodiethanolamine (NDELA) were applied to the clipped dorsal skin (about 3.5 X 3.5 cm) of adult male Fischer 344 rats. NDELA was applied undiluted, dissolved in water and dissolved in cutting oil; NMOR was applied dissolved in water and in ethyl acetate. To compare the extent of absorption through the skin with that from the stomach, aqueous solutions of the nitrosamines were used for gavage. Blood and urine samples were analysed for nitrosamines, using GC-TEA or HPLC-TEA. Maximum skin penetration observed with NMOR was 56%, following application of 5 mg, whereas a similar proportion of the dose was regularly present after gavage of 5 mg. Less than 1% was recovered from the urine. Skin painting of NDELA in water (20 mg in 100 microliter) and in cutting oil (25 mg in 25 microliter) yielded small concentrations of NDELA in the blood; less than 25 mg/l in all cases. However, when 50 mg NDELA was painted on the skin undiluted, from 130 to 220 mg/l of blood were recovered after one hour. fifty mg NDELA in water yielded similar blood concentrations when administered by gavage. From 20 to 30% of the NDELA applied undiluted and by gavage were recovered in the urine. It is concluded that, although there are differences between animals, exposure to NMOR or NDELA represents a risk due to absorption through the skin.

Animals↗
PubMed1978

The effect of probe bluntness on sampling particulates from calm air.

The size-selective characteristics of circular inlets as a function of bluntness was examined using polydisperse spherical glass beads. Four levels of bluntness (0.5, 1, 5, and 50) and three sampling velocities (4, 20, and 40 cm/sec) were studied. Particle count and weight percent distributions were determined using a 15-channel electronic counter. At a sampling velocity of 40 cm/sec the weight percent distributions shifted toward particles of larger diameters with increasing bluntness. Little or no effect was discerned at sampling velocities of 20 and 4 cm/sec. As the velocity increased from 4 to 40 cm/sec at constant bluntness, the weight percent distributions shifted away from larger diameter particles. The results suggest that at some sampling conditions probe bluntness may be a variable which deserves consideration in particulate sampling.

Aerosols↗
PubMed1978

The permeability of laboratory gloves to selected nitrosamines.

Samples of laboratory gloves of various composition and thicknesses were used as barriers between 0.136 M solutions of nitrosamines (dimethyl-, ethylmethyl-, diethyl-8 n-butylmethyl-, di-n-propyl-, di-iso-propyl- and di-sec-butyl- in dichloromethane, acetone, ethanol and double-distilled, deionized water) and water. The concentration of permeated nitrosamine was measured periodically. Nearly all gloves tested were permeable to the nitrosamine solutions. The results indicate that: (1) gloves should not be assumed to provide full protection, (2) gloves should be discarded immeidately following overt contamination and (3) gloves should not be reused.

Hand↗
PubMed1977

Sources and dissemination of contamination in material handling operations.

To assess the potential risks to personnel preparing feed for carcinogen bioassay research, a tracer was mixed with a meal diet to yield 10 kg batches of 100, 3,000 and 5,890 ppm. Wipe samples were obtained from horizontal and vertical surfaces, equipment and personnel before operations began, after they were completed, and following clean-up. Total and respirable suspended particulate matter samples were obtained. All operations led to contamination of clothing and equipment; cleaning did not remove all contamination. These results, obtained in a well controlled environment in which trained and well protected personnel were working, suggest that a higher level of process control may be required for adequate protection of personnel performing material handling operations with known or suspected carcinogens.

Air Pollutants↗