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Biomedical subjects

V J Feron

Publications and source records attributed to V J Feron.

At least 127 records · Page 7Linked to original sources
PubMed1981

Repeated exposure to alpha-ethylacrolein vapour: subacute toxicity study in rats.

The subacute inhalation toxicity of alpha-ethylacrolein was examined in rats by repeated exposure of 4 groups of 10 males and 10 females each to alpha-ethylacrolein vapour at concentrations of 0, 2.0, 9.8 or 48.4 ppm, respectively, (6 h/day, 5 days/week) for a period of 13 weeks. The effects at 48.4 ppm were found to include growth retardation, focal alopecia, increased activity of glutamic-oxalacetic transaminase, glutamic-pyruvic transaminase and alkaline phosphatase in the blood serum, decreased concentrations of total protein and albumin in the blood serum, increased relative weight of the heart, liver, adrenals and lungs, and histopathological changes in the respiratory tract mainly consisting of hyper- and metaplasia of respiratory epithelium and atrophy of the nasal olfactory epithelium. While at the 9.8 ppm level only a few relatively minor effects were noticed, viz. decreased concentrations of total protein and albumin in the blood serum and minimal hyper- and metaplasia of the tracheobronchial epithelium, no changes attributable to alpha-ethylacrolein were observed at the 2.0 ppm level.

Acrolein↗
PubMed1980

Significance of particle size of benzo(a)pyrene for the induction of respiratory tract tumours in hamsters.

To study the role of particle size of benzo(a)pyrene (BP) in the induction of respiratory tract tumours, goups of hamsters were given 52 weekly intratracheal instillation of fine (77% less than 5.2 micron; 3% less than 1.3 micron) or coarse (77 less than 42 micron; 0% less than 10 micron) BP particles suspended in gelatin-0.9% NaCl solution. Both the fine and coarse particles were given at two different dose levels, viz., 0.5 and 1.0 mg BP/instillation. Another group of hamsters received 52 weekly intratracheal instillations each consisting of 1.0 mg BP particles of a wide size range (90% less than 50 micron; 3% less than 5.0 micron) suspended in 0.9% NaCl solution without gelatin. The retention of BP in the respiratory tract was studied in separate groups of hamsters receiving a single instillation of BP particles of the different size ranges. Coarse BP particles cleared less rapidly from the lungs and induced a much stronger tumour response in the respiratory tract than did fine BP particles. These findings demonstrated the crucial significantce of particle size for the effectiveness of BP as a respiratory tract carcinogen. No appreciable differences in site of tumour formation were observed between treatment with fine and coarse BP particles, which led to the conclusion that the size of the particles did not play an important role in determining the location of the induced respiratroy tract tumours. The elimination rate of the BP particles with a wide size range appeared to be in between those of the fine and the coarse particles. The tumour response found after administration of the BP particles of wide size range was very similar to that obtained with the high dose of coarse PB particles.

Animals↗
PubMed1979

Repeated exposure to butenolide vapour: subacute study in Syrian golden hamsters.

The subacute inhalation toxicity of butenolide was examined in hamsters by repeated exposure of 4 groups of 10 males and 10 females to butenolide vapour at concentrations of 0, 5.4, 25 and 130 ppm respectively (6 h/day, 5 days/week) for a period of 13 weeks. The effects found at 130 ppm included eye irritation, salivation, nasal discharge, growth retardation, decreased number of eosinophils, increased liver weight, and hyper- and metaplastic epithelium in the nasal cavity. At the 5.4 and 25 ppm levels no changes were observed which could be attributed to butenolide; 25 ppm was, therefore, considered the highest no-toxic effect level observed. The actual no-adverse effect level was placed at 75 ppm.

4-Butyrolactone↗
PubMed1979

Repeated exposure to furfural vapour: 13-week study in Syrian golden hamsters.

The sub-acute inhalation toxicity of furfural was studied in Syrian golden hamsters. Four groups of ten males and ten females each were repeatedly exposed to furfural vapour at concentrations of 0, 20, 115 and 552 ppm (0, 77, 448 and 2165 mg/m3 air) respectively for 6 hours/day, 5 days/week during a period of 13 weeks. At the highest exposure level furfural induced irritation of the eyes and nose, slight growth retardation and atrophy along with hyperplasia of the olfactory epithelium in the nasal cavity. At 115 ppm atrophy and hyperplasia of the olfactory epithelium were the only adverse effects observed that could be attributed to furfural. No compound-related alterations were detected at the lowest exposure concentration of 20 ppm (77 mg/m3 air) which was, therefore, accepted as a no-toxic effect level.

Animals↗
PubMed1979

One-year time sequence inhalation toxicity study of vinyl chloride in rats. I. Growth, mortality, haematology, clinical chemistry and organ weights.

Wistar rats were exposed to atmospheres containing O (control) or 5000 ppm vinyl chloride monomer (VCM), 7 h/day, 5 days/week, for a period of 52 weeks. After 4, 13, 26 and 52 weeks each time 10 rats/sex/group were killed and subjected to extensive examinations. The present paper deals with growth, mortality, haematology, clinical chemistry and organ weights. Slight growth retardation throughout the experimental period and high mortality in the second half of the study were observed in VCM-exposed animals. Some of the haematological parameters and biochemical blood parameters were slightly influenced by VCM after an experimental period of 52 weeks only. Blood clotting time was generally slightly shorter in VCM-exposed rats than in controls. There were minor indications of increased potassium contents of the blood serum in VCM-exposed animals during the first half of the test period. The kidneys were adversely affected by VCM as appeared from increased blood urea nitrogen levels and relative kidney weights. After 52 weeks increased weights of heart and spleen, and slight signs of anaemia were noticed in VCM-exposed rats. The present study did not produce obviously suitable parameters for early diagnosing "VCM-disease" in man.

Animals↗
PubMed1978

Repeated exposure to acrolein vapour: subacute studies in hamsters, rats and rabbits.

The subacute inhalation toxicity of acrolein was examined in 4 groups of 20 hamsters, 12 rats and 4 rabbits each, exposed repeatedly to acrolein vapour at concentrations of 0, 0.4, 1.4 and 4.9 ppm (6 h/day, 5 days/week) for a 13-week period. The most important effects found at the highest level included mortality in rats, ocular and nasal irritation, growth depression and histopathological changes of the respiratory tract in each of the animal species exposed. The aberrations in the airways consisted of destruction and hyper- and metaplasia of the lining epithelium accompanied by inflammatory alterations. Rats appeared to be the most susceptible of the species examined and showed treatment-related abnormalities even at 0.4 ppm, whereas this exposure level was found to be a no-toxic effect level in both hamsters and rabbits.

Acrolein↗
PubMed1978

Effects of exposure to furfural vapour in hamsters simultaneously treated with benzo[alpha] pyrene or diethylnitrosamine.

Syrian golden hamsters were exposed to 0 or 250/400 ppm furfural vapour, 7 h/day, 5 days/week for a period of 52 weeks. Simultaneously, a proportion of the animals were given either intratracheal inslillations of benzo [alpha] pyrene (BP) or subcutaneous injections of diethylnitrosamine (DENA). All treatments were stopped after 52 weeks. The study was terminated after 81 weeks. Furfural exposure caused yellowish discolouration of the animals' coat, irritation of the nasal mucosa, growth retardation, atrophy and downward growth of sensory cells of the olfactory epithelium, degenerative changes in Bowman's glands, and the occurrence of cyst-like structures in the lamina propria beneath the olfactory epithelium. There was no evidence of furfural possessing carcinogenic activity. In a previous instillation experiment with furfural, slight indications had been obtained of furfural potentiating the carcinogenic effect of BP, but in the present study the carcinogenic effect of BP or DENA on the respiratory tract did not appear to be influenced by furfural exposure. It was concluded that little if any, significance can be attached to furfural as a co-factor in respiratory tract carcinogenesis.

Adenoma↗
PubMed1976

Effects of alkali-treated proteins: feeding studies with free and protein-bound lysinoalanine in rats and other animals.

To find out whether alkali-treated proteins posses nephrotoxic properties, feeding studies were conducted with drastically treated soybean protein and casein, and also with lysinoalanine (LAL), the amino acid known to be formed in protein subjected to high pH at elevated temperature. The feeding of synthesized LAL to rats at dietary levels of 100 ppm and above induced typical renal changes, called nephrocytomegalia. No such changes or any other indications of toxicity were observed, however, upon feeding much higher levels of LAL (up to 6,000 ppm) when provided as the protein-bound compound in alkali-treated casein or soybean protein. When set free by complete acid hydrolysis, LAL induced considerable renal activity, comparable to that of the synthetic compound. These results indicate that alkali treatment of proteins does not induce nephrotoxic properties provided that the compound remains protein-bound. Some nephrotoxic activity was observed, however, with peptide-boound LAL in break-down products (molecular weight less than 5,000) of alkali-treated casein, but considerably less than that of the free compound. LAL-analyses in blood, urine, and feces of rats fed free or protein-bound LAL indicated a positive correlation between intestinal absorption and nephrotoxic potential. No renal changes were encountered upon feeding diets with 1,000 ppm synthetic LAL to mice, hamsters, rabbits, quail, dogs or monkeys, which suggest a species specificity of LAL-induced renal changes in rats.

Animals↗
PubMed1976

Clearance of benzo(a)pyrene from the respiratory tract of hamsters following its intratracheal instillation with or without ferric oxide.

A comparative study was carried out on the clearance of benzo(a)pyrene (BP) from the respiratory tract of Syrian golden hamsters following intratracheal instillation of either BP alone or BP attached to ferric oxide particles. Eight series of 18 hamsters each, received a single intratracheal instillation of 0.5 or 1.0 mg BP suspended in 0.9% NaCl solution. In addition, three comparable series of hamsters received in the same way a mixture, of 1.0 mg BP + 1.0 mg ferric oxide suspended in 0.9% NaCl solution. In each of the series the BP content of the respiratory tract was determined at six different points of time viz. immediately after administration of BP or BP + ferric oxide, and three, six and 24 hours, and three and seven days after an instillation. The clearance of BP from the respiratory tract did not appear to be significantly influenced by the presence of ferric oxide. It was concluded that the present study produced no evidence of ferric oxide particles being capable of enhancing the retention of BP in the respiratory tract.

Animals↗
PubMed1976

Repeated exposure to cyclopentenone vapour: long-term study in Syrian golden hamsters.

Effects of cyclopentenone inhalation were examined in a 78-week study with 420 hamsters evenly distributed over two inhalation chambers, one for exposure to air and the other for exposure to the test substance. Cyclopentenone was dosed at a level of 18 ppm (seven hr/day, five days/week) during the first 52 weeks, and at a level of 27 ppm during the last 26 weeks of the study. During the first 52 weeks, part of the animals in both chambers fortnightly received an intratracheal instillation of benzo(a)pyrene (BP) or diethylnitrosamine (DENA) in saline or saline alone. Exposure to cyclopentenone caused slight growth depression in both sexes, and slightly increased relative liver weights and enhanced development of renal amyloidosis in females only. There was no evidence of cyclopentenonne possessing carcinogenic activity or being a co-factor in respiratory tract carcinogenesis.

Amyloidosis↗