Biomedical subjects

V E Valli

Publications and source records attributed to V E Valli.

At least 127 records · Page 7Linked to original sources

PubMed1983

A teratological assessment of four trihalomethanes in the rat.

Four trihalomethanes were administered by gavage to Sprague-Dawley rats from day 6 to day 15 of gestation. Chloroform (Ch) was administered at levels of 100, 200 and 400 mg/kg and bromoform (Br), bromodichloromethane (BDCM) and chlorodibromomethane (CDBM) were administered at levels of 50, 100 or 200 mg/kg/day. A separate control was used for each compound. Maternal weight gain was depressed in all groups receiving Ch and at the highest dose levels of BDCM and CDBM. Ch administration caused decreased maternal hemoglobin and hematocrit values at all dose levels and also produced increased serum inorganic phosphorus and cholesterol at the highest dose. Liver enlargement was observed at all dose levels of Ch but in no other treatment groups. Evidence of a fetotoxic response was observed with Ch, CDBM and Br but not BDCM. No dose-related histopathological changes were observed in either mothers or fetuses as a result of treatment. None of the chemicals tested produced any teratogenic effects.

Animals↗

PubMed1983

Oral toxicity of malonaldehyde: a 90-day study on mice.

The oral toxicity of malonaldehyde (MA), a product of lipid peroxidation found in some foods, was investigated in a 90-d study on mice, MA as the sodium enol salt was administered in the drinking water to 8-wk-old female Swiss mice at levels calculated to provide 2, 10, 50, 250, or 500 micrograms/g body weight . d. There was no mortality and all groups gained weight at comparable rates except that those that received 500 micrograms/g body weight . d gained more slowly and lost weight after 50 d. Histopathological examination of 27 tissues indicated that the liver was the only organ that underwent dose-dependent changes. All levels of MA induced irregularities (anisokaryosis, hyperchromicity, vesiculation) of hepatic nuclei. Pancreatic lesions consisting primarily of atrophy of the exocrine cells with loss of zymogen granulation occurred in animals which received 500 micrograms MA/g body weight . d. Mild dysplasia of the urinary bladder epithelium was found in all treatment groups. Approximately 1% of the dose was excreted unchanged in the urine at each level of administration.

Administration, Oral↗

PubMed1983

Vomitoxin in corn fed to young pigs.

Four trials were conducted with young pigs to evaluate the effect of dietary level of vomitoxin-contaminated corn on performance and pathology. A dietary level of approximately 20 ppm vomitoxin caused vomiting, 12 ppm vomitoxin caused almost complete feed refusal and 1.3 ppm caused a significant depression in feed intake and rate Of gain. No lesions attributable to vomitoxin were observed in pigs fed up to 43 ppm dietary vomitoxin for a 21-d period. Alterations in various blood serum characteristics were observed in pigs fed vomitoxin, however, the effects could not be separated from those that may result from low intake of food.

Animals↗

PubMed1983

Exposure of calves to aerosols of parainfluenza-3 virus and Pasteurella haemolytica.

The present study was undertaken to investigate whether sequential exposure to aerosols of parainfluenza-3 virus followed by Pasteurella haemolytica, or P. haemolytica followed by parainfluenza-3 virus, could lead to the production of pulmonary lesions in conventionally-raised calves. Twenty male calves with low serum antibody titres to both organisms were placed in five equal groups. Synergism of parainfluenza-3 virus and P. haemolytica was not demonstrated in any of the sequentially infected groups and pulmonary lesions were mild in all challenged calves. Clinical signs of disease were not present after exposure to parainfluenza-3 virus although the virus was repeatedly isolated from nasal secretions of all inoculated calves. Exposure to P. haemolytica produced a transient response which consisted of increased rectal temperatures and respiratory rates, with a mild neutrophilic leukocytosis and a mild left shift present six hours postinoculation and returning to normal within 24 hours. Results from this study suggest, although do not confirm, that reduced pulmonary clearance of inhaled P. haemolytica in parainfluenza-3 virus infected calves does not necessarily lead to production of severe pulmonary lesions and that previous exposure to aerosols of P. haemolytica may not enhance secondary parainfluenza-3 virus infection.

Aerosols↗

PubMed1983

Influenza hemagglutination inhibiting activity in respiratory mucus from horses with chronic obstructive pulmonary disorders (heaves syndrome).

Samples of mucus from the lower trachea were collected from 53 horses with chronic obstructive pulmonary disease and from 24 clinically normal horses. Serum samples were collected from 35 of the horses with chronic obstructive pulmonary disease and from the 24 normal horses. Samples were tested for inhibition of hemagglutination by influenza A equine 1 and 2 viruses. There were high levels of hemagglutination inhibiting activity against influenza A equine 1 in mucus samples from horses with chronic obstructive pulmonary disease.

Animals↗

PubMed1982

Ultrastructure of the thyroid glands of rats fed photomirex: an 18-month recovery study.

The thyroid glands, from rats which had received photomirex (0.05, 0.5, 5 or 50 ppm) or mirex (5 or 50 ppm) in their diets for 28 days and maintained for 18 months on clean diet, were examined by electron microscopy. A dose of 0.05-5 ppm photomirex resulted in an augmentation of principal follicular cell heights. Their cytoplasm exhibited a marked numerical increase of secondary lysosomes. In addition, at 5 ppm, follicular cells in some segments of the gland contained only a few secondary lysosomes. After dietary exposure to 50 ppm photomirex the number of lysosomal elements remained elevated in epithelial cell cytoplasm. Morphological aberrations in the follicles could not be detected after the 5 ppm mirex treatment. The most remarkable alterations in this experiment occurred in the thyroid glands of animals ingesting 50 ppm mirex where columnar follicular cells were engorged with deformed lysosomal bodies. Remaining components of the follicular cell architecture in all the treated groups were unaffected and were similar to those in the control group. These results demonstrated that following a 28-day dietary exposure of rats to photomirex (0.05-50 ppm) or mirex (50 ppm), alterations in the thyroid glands persisted for at least 18 months.

Administration, Oral↗

PubMed1982

Toxicity of trihalomethanes: I. The acute and subacute toxicity of chloroform, bromodichloromethane, chlorodibromomethane and bromoform in rats.

In an acute study, groups of 10 male and 10 female rats were given single oral doses of chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM), or bromoform and were observed for clinical symptoms for the following 14 days. Median lethal doses (LD 50) of the four trihalomethanes were found to be between 848 and 1388 mg/kg. Some groups which survived the treatment for 14 days showed reduced food intake, growth retardation and increased liver and kidney weight. Elevated serum cholesterol levels were observed in the surviving male rats treated with chloroform and CDBM, and in the females treated with chloroform. Decreased liver protein content occurred in male but not female rats fed chloroform and bromoform. In contrast, increase aniline hydroxylase activity was observed in female rats fed chloroform but not bromoform. Hematological values which were altered by the four trihalomethanes were hemoglobin, hematocrit, RBC, WBC, neutrophil and lymphocyte counts. Treatment-related histologic changes were observed in the liver and kidney of rats. These changes were qualitatively and quantitatively similar for the four trihalomethanes. These data indicate that trihalomethanes at large single oral doses can produce a wide range of toxic changes in the rat. In a subacute study, groups of 10 male rats were fed four trihalomethanes at 0, 5, 50 or 500 ppm in their drinking water for 28 days. The growth rate and food intake were not affected by treatment. A slight increase in relative kidney weight was observed in the groups fed 5 ppm chloroform; 500 ppm bromoform, 5 and 500 ppm BDCM. The animals fed the highest dose of chloroform showed decreased neutrophils. Serum biochemical parameters and hepatic microsomal enzyme activities were not altered by any of the four trihalomethanes. No histopathological changes were seen in the tissues examined.

Animals↗

PubMed1982

Trihalomethanes: II. Reversibility of toxicological changes produced by chloroform, bromodichloromethane, chlorodibromomethane and bromoform in rats.

Groups of 20 male and 20 female rats were fed 0, 5, 50, 500 or 2500 ppm trihalomethanes (chloroform, bromodichloromethane, chlorodibromomethane and bromoform) in their drinking water for 90 days. Ten rats from each group were killed at this time and the remaining animals were fed tap water for a further 90 days before they were sacrificed. Suppression of growth rate was observed in male and female rats fed 2500 ppm chloroform and bromodichloromethane (BDCM) for 90 days. After the subsequent 90-day recovery period, no effects on body weight gain in either sex were apparent. Food consumption was depressed in all groups of males and females receiving 2500 ppm chloroform, chlorodibromomethane (CDBM) and BDCM for 90 days and in these same groups during the recovery period. Bromoform at 2500 ppm suppressed food consumption of male rats but this effect was not evident 90 days after cessation of exposure. Decreased lymphocyte counts were only observed in the recovery groups fed chloroform (500 ppm, male), CDBM (2500 ppm, female) and bromoform (2500 ppm, females). Histological changes in the livers and thyroids of male and female rats were qualitatively and quantitatively similar for the four trihalomethanes. These changes were mild in nature, and were not evident 90 days after cessation of exposure. These data indicate that trihalomethanes can produce biochemical hematological and histological changes but most of these were reversible when exposure had terminated.

Animals↗

PubMed1982

Acute and subacute toxicity of octachlorostyrene in the rat.

This study was designed to investigate the acute and subacute toxicity of octachlorostyrene (OCS), a demonstrated environmental pollutant in fish from the Great Lakes and off the Norwegian coast in Europe. In an acute study, groups of 10 male rats were given by gavage single doses of OCS at 1300, 1690, 2190, 2850, or 3710 mg/kg and killed 14 d later. Octachlorostyrene at a dose of 1690 mg/kg and higher caused increased liver weight, increased hepatic microsomal aniline hydroxylase and aminopyrine demethylase activities, and increased serum cholesterol and uric acid levels. Only mild histological changes were seen in the thyroid of the treated animals. In a subacute study, groups of 10 male and female rats were fed diets containing 0.5, 5.0, 50 or 500 ppm OCS for 28 d. Growth rate and food consumption were not affected by treatment. Liver hypertrophy and hepatic microsomal enzyme induction were observed in animals fed 50 ppm OCS or higher. Elevations in serum cholesterol, total protein, potassium, and sorbitol dehydrogenase (SDH) occurred in rats fed the 500 ppm diet. Histological changes occurred in the liver and thyroid of rats exposed to as low as 5.0 ppm OCS. The OCS residues accumulated in the fat and liver in a dose-dependent manner. These data suggest that OCS can produce biochemical and histological changes in rats after administration of a single oral dose and/or when fed in the diet.

Animals↗

PubMed1982

Toxicological evaluation of malonaldehyde: a 12-month study of mice.

The chronic toxicity of malonaldehyde (MA) was evaluated using Swiss female mice. Beginning at 10 wk of age, MA was administered in the drinking water for 12 mo to groups of 50 animals at levels of 0.1, 1, and 10 micrograms/g body wt.d with 100 controls. The highest dose was associated with increased mortality (28% versus 12-14%). MA had no effect on body weight, organ weight, hematological indices, or the incidence of lesions in 27 tissues examined. More liver lesions were observed in the three treatment groups than in the controls (p less than 0.05), and the histopathologic scores for severity of lesions were significantly increased in the groups that received the two higher levels of MA. The liver lesions included anisokaryosis, changes in cytoplasmic volume with architectural derangements, necrosis and neoplastic changes (nodular hyperplasia, hepatoma, and hemangioma). There was no significant increase in specific neoplasms in the treated groups, but the incidence of total neoplasms and neoplastic lesions was dose-dependent (4%, 8%, and 12%, respectively) (p less than 0.01). There was only one neoplasm (a hemangioma) among the controls (1%). Three animals (6%) given the highest dose of MA developed stomach neoplasms. In terms of human dietary exposure to MA, the lowest level of MA used in this study is about 10 times the estimated average daily intake of MA by the Canadian population on a body weight basis.

Animals↗

PubMed1982

Morphology and cytochemistry of bovine bone marrow mononuclear phagocytes.

Bone marrow samples were collected from five normal calves and mononuclear cells were separated using Ficoll-Hypaque. Mononuclear cells were cultured on coverslips in Leighton tubes for six hours. The adherent cells were differentiated using Wright's and nonspecific esterase stains. Monoblasts, promonocytes and monocytes were present in the proportion of 1:2.31:4.96.

Animals↗

PubMed1982

Proliferative, morphologic, and cytochemical characteristics of bovine bone marrow macrophage colonies in liquid culture.

Bovine macrophage colonies were grown in liquid medium. Serum collected from a heifer 3 hours after injection of Pseudomonas aeruginosa endotoxin promoted the growth of macrophage colonies. The optimum concentration of postendotoxin serum was 16%. The numbers of colonies increased exponentially between 3 and 6 days of incubation and leveled off at 6 days. Monoblasts, promonocytes, and macrophages were observed in these colonies. A direct linear relationship between the number of nucleated bone marrow cells cultured and the number of colonies formed was found. The macrophage colony cells were positive for nonspecific esterase activity and were negative for chloroacetate esterase activity. Weak peroxidase activity was noticed in monoblasts, promonocytes, and occasionally in macrophages.

Animals↗

PubMed1982

The kinetics of mononuclear phagocytes in normal calves given Corynebacterium parvum.

Two groups of calves, three in each group, were used to determine the kinetics of mononuclear phagocytes in normal calves and in calves given Corynebacterium parvum intravenously, using tritiated thymidine as an in vivo deoxyribonucleic acid label. In normal calves, the mean production time of labelled monocytes in the bone marrow was 36.4 +/- 2.04 hours. The turnover rate of labelled monocytes from the bone marrow into the peripheral blood was 5.4 +/- 0.3% per hour and the disappearance rate of labelled monocytes from the circulation was 0.9 +/- 0.3%. The half lives of labelled blood monocytes were 22.5 hours for cells with 16-30 grains and 19.5 hours for cells with 31-50 grains. Alveolar macrophages were derived from peripheral blood monocytes. In calves given C. parvum, the production time, turnover rate and half lives of labelled monocytes did not differ significantly (p greater than 0.05) from the values in normal calves.

Animals↗

PubMed1982