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Biomedical subjects

E Bingham

Publications and source records attributed to E Bingham.

At least 55 records · Page 3Linked to original sources
PubMed1979

Bioassay of complex mixtures derived from fossil fuels.

The conversion or processing of shale, coal, or petroleum involves elevated temperatures and altered pressures, and under these conditions polynuclear aromatic hydrocarbons are likely to form. Certain compounds of this type exhibit carcinogenic activity for a variety of organ sites in experimental animals and epidemiological evidence strongly implicates their role as carcinogens in man. It is then not unexpected that many liquid fractions derived from shale and coal are carcinogenic when subjected to bioassay. Benzo(a)pyrene, [B(a)P], is frequently considered to be an indicator substance. It is clear that when a small quantity of B(a)P is present in a fraction, the fraction will exhibit carcinogenic activity in a bioassay (mouse skin). However, it does not follow that the lack of detectable B(a)P insures that the fraction will be noncarcinogenic. Several fractions have been analyzed for their content of B(a)P and then subjected to bioassay. A method for testing complex mixtures for their carcinogenic potential is described. The carcinogenic potency of these fractions are compared to petroleum fractions.

Animals↗
PubMed1977

Cocarcinogenic effects of n-alkanes and ultraviolet light on mice.

A comparison was made of the effects of repeated topical applications to mice of three n-paraffins (n-decane), n-dodecane, and n-tetradecane) on the carcinogenic potential of UV light at three wavelength regions: 254 nm, 290-320 nm, and greater than 350 nm. All three n-alkanes had a cocarcinogenic effect at 254 nm, whereas only n-dodecane was effective from 290 to 320 nm. Radiation at wavelengths longer than 350 nm, generally considered noncarcinogenic, produced tumors on the backs of mice treated with n-decane or n-tetradecane.

Alkanes↗
PubMed1976

Metabolism of environmental pollutants by the isolated perfused lung.

An isolated perfused rabbit lung system was developed for the study of pulmonary metabolism of foreign compounds. The main features of the system include the use of autologous whole blood, constant pressure perfusion, subatmospheric ventilation, and measurement of a variety of physiological and biochemical parameters. Pulmonary metabolism of benzo(a)pyrene has been investigated with this system. In addition to the 3-hydroxy metabolite, three dihydrodiols and an unidentified polar metabolite were also found. The polar metabolite accounted for approximately 50% of all metabolites found in the five compartments of the perfusion system. Pretreatment with 3-methylcholanthrene increased total metabolism of benzo(a)pyrene and shifted the pattern of metabolites. The perfusion system for the rabbit has been extensively modified for use with rats and guinea pigs. These smaller animals are currently being used to investigate pulmonary metabolism of trichloroethylene.

Animals↗
PubMed1975

Pulmonary response to polyurethane dust.

Weanling and 9 months or older rats were exposed to particles of an aged (PUF I) or freshly prepared (PUF II) rigid polyurethane foam by intratracheal intubation. The dose was 5 mg of particles. The response of the lung tissue was examined morphologically by serial sacrifices. Inflammation and macrophage activity were the initial responses. Fibrosis developed after 6 months. Nodular scars and perifocal emphysema were seen after 12 months. Four rats had a papillary adenoma in a major bronchus after 18 months exposure to PUF II.

Age Factors↗
PubMed1975

Investigation of alveolar macrophages from rats exposed to coal dust.

Rats were exposed to the inhalation of coal dust from either Utah (low prevalence coalworkers' pneumoconiosis (CWP)) or Pennsylvania (high prevalence CWP). Rats were sacrificed, the lungs removed and lavaged to obtain free cells. The number of alveolar macrophages recovered from rats inhaling these two coal dusts (exposures up to 4 months) was not remarkably different from the number recovered from rats inhaling filtered room air. This is in contrast to results obtained after intratracheal intubation of the dust. The capacity of the lavaged cells to phagocytize and kill bacteria decreased after exposure to either dust. The activity of certain enzymes also decreased.

Acid Phosphatase↗