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Biomedical subjects

S Odend'hal

Publications and source records attributed to S Odend'hal.

17 recordsLinked to original sources
PubMed1990

Effect of oral dosing vehicles on the acute hepatotoxicity of carbon tetrachloride in rats.

Although carbon tetrachloride (CCl4) is of concern as a drinking water contaminant, it has been necessary in most oral toxicity studies to give CCl4 in an oil vehicle due to its limited water solubility. The primary objective of our study was to assess the influence of dosing vehicles on the acute hepatotoxicity of CCl4. Fasted 200- to 230-g rats were generally found to be more susceptible to CCl4 hepatotoxicity than fasted 300- to 330-g rats. A time-course study revealed that corn oil did not delay the onset or time of maximal liver injury by an oral 100 mg/kg dose of CCl4, but did reduce the extent of injury relative to that when the chemical was given undiluted or as an aqueous emulsion. Fasted 200- to 230-g male Sprague-Dawley rats were given 0, 10, 25, 50, 100, 250, 500, or 1000 mg CCl4/kg body wt by gavage: in corn oil; as an aqueous emulsion; as the undiluted chemical; and in the 10 and 25 mg/kg doses only, in water. Blood and liver samples were taken 24 hr after dosing for measurement of serum and microsomal enzymes. Pathological examination of liver samples was also conducted. Dose-dependent increases in serum enzyme levels and pathological changes and dose-dependent decreases in microsomal P450 and glucose-6-phosphatase activity were observed in each vehicle group. Both the 10 and 25 mg/kg oral doses of CCl4 in water caused significant elevations in serum enzymes and hepatic centrolobular vacuolation. The study revealed that acute hepatotoxicity was less pronounced at each dosage level in rats given CCl4 in corn oil than in other vehicle groups. These findings demonstrate that dosing vehicles can significantly influence the acute hepatotoxicity of CCl4 in rats and are a cause for additional consideration and review of the practice of routinely using vegetable oils as a diluent in studies of volatile organic compound (VOC) toxicity. The use of aqueous Emulphor emulsions appears more appropriate in acute toxicity studies of VOC drinking water contaminants such as CCl4, in that the emulsion did not substantially alter the toxicity of CCl4 from that of undiluted CCl4 or CCl4 ingested in water.

Administration, Oral↗
PubMed1988

Human and cattle population changes in upland West Bengal, India between 1977-1978 and 1987.

"Six villages in upland West Bengal, India, were resurveyed in 1987 and the results compared with the data from a larger area studied in 1977-1978. There has been a 6.4% increase in the human population, but the number of households has decreased by 1.7%. The cattle population has increased 14.4% with male cattle accounting for the bulk of the increase. A crossbreeding program implemented 8 years ago has had virtually no beneficial effects. Other observations on the general welfare of humans and domestic animals are presented."

Agriculture↗
PubMed1986

The rete ovarii of cattle and deer communicates with the uterine tube.

Textbooks in embryology, histology, and reproductive biology erroneously state that the mammalian rete ovarii consists of a tubular structure in the medulla of the ovary which is closed at both ends. In white-tailed deer and cattle, the lumen of the rete ovarii opens directly into the infundibulum near its attachment to the ovary. This serendipitous discovery followed the serial sectioning of over 100 ovaries. Secretions through this tuboretial opening may affect reproductive processes. Obstructions could explain the development of cysts of clinical importance in both human and veterinary medicine. This rather obscure structure may have more significance than previously recognized.

Animals↗
PubMed1986

Bovine leukosis: an example of poor disease monitoring of international livestock shipments to developing countries.

Over the past few years, cattle imported into a number of countries have been shown to carry antibodies against bovine leukosis virus (BLV), the cause of enzootic bovine leukosis. The disease, imported into England via shipments of Canadian dairy cattle in the late 1970s, is still a significant problem in the United Kingdom. Many countries now require a blood test for serum antibodies to BLV as a precondition of shipment from certain endemic countries. Those cattle positive for BLV are excluded from shipment. Well-documented cases of shipments of hundreds of Canadian cattle without testing for BLV has been obtained. These shipments were to the African country of Malawi where the BLV status is unknown. Also, although the United States is endemic for BLV, most of the recent live cattle exports were received by countries which did not require a blood test for BLV. Of the 44 countries that imported U.S. cattle during 1982 and 1983, only 13 required BLV antibody testing before shipment. This report concerns one disease in one species. The millions of livestock shipped yearly between the countries of the world may harbor many viruses at risk of being introduced into susceptible animal populations. While international animal health agencies are doing a credible job of providing disease surveillance to member countries, there still needs to be improvements in disease information dissemination.

Animals↗
PubMed1985

The mammalian rete ovarii: a literature review.

The rete ovarii is the homologue of the rete testis. It develops from cells of mesonephric origin which immigrate into the developing gonad of the embryo. The mature form of the rete ovarii is generally found to be groups of anastomosing tubules lined by cuboidal or columnar epithelium. These tubules are usually located in the hilus of the ovary, but may extend through the medulla or be isolated in the mesovarium adjacent to the hilus. The rete is often continuous with the transverse ductules through which it contacts the longitudinal duct of the epoophoron. The rete ovarii is important in the control of meiosis in the maturing ovary. Cells of the rete ovarii differentiate to form granulosa cells as well. The rete is also credited with secretory capability, a hypothesis supported by the observation of secretory material in the lumina of the rete tubules in several species. Cysts have been observed in the rete ovarii of several species. The rete ovarii of the adult does not appear to be a functionless vestige as has been previously reported.

Aging↗
PubMed1980

Cattle ecology of upland and deltaic areas of West Bengal.

Two large cattle populations were enumerated by a house to house survey in several villages in upland and deltaic regions of rural West Bengal, India. The basic population parameters of the 2 were compared and their inter-relationships related to the different environmental setting of each region. The total number, density, sex ratio, age distribution, number per household, basic productivity and general management of the cattle differed significantly. While the male cattle were activity bought and sold into and out of each region, the female cattle appeared to represent a relatively unmanipulated subpopulation in both regions. The cattle in each area consumed items of little direct human utility and converted them into valuable materials highly desired by the respective human populations.

Age Factors↗
PubMed1980

An area of T cell localization in the cloacal bursa of White Leghorn chickens.

Within the cloacal bursa (bursa of Fabricius), there is a diffusely infiltrated area (DIA) of lymphoid cells just dorsal to the bursal duct opening. Because this region displayed certain histologic characteristics of thymus-dependent areas found in mammals, such as high endothelial venules, heavy reticular fiber components, and epithelium infiltrated with lymphocytes, experiments were conducted to determine whether thymus-derived cells (T cells) were present. Two independent methods substantiated the presence of T cells in the DIA. After the acid alpha-naphthyl acetate staining technique, the characteristic T cell focal esterase activity could be demonstrated in significant numbers of cells found in the DIA. Also autologous radioactively labeled thymocytes could be identified in the DIA by autoradiography a few hours after IV injection. This establishment of a definite T cell area within the bursa gives additional credence to the contention that the bursa functions as a secondary lymphatic organ.

Animals↗
PubMed1979

Luminal lymphoid cells of the cloacal bursa.

Following cloacal bursal lavage of 1- to 4-week-old White Leghorn chickens, substantial numbers of viable mononuclear cells can be demonstrated in the effluent. These cells are predominantly lymphocytes and have been examined by light microscopy, and transmission and scanning electron microscopy. Their possible origin, fate, and function are discussed.

Animals↗
PubMed1966

Pressure regulation in the middle ear cavity of sea lions: a possible mechanism.

The mucosa lining the cavity of the middle ear of sea lions contains a complex network of venous channels and sinuses. During dives the pressure within the middle ear may be equalized with that in the external auditory meatus either by the distention or depression of the mucosa due to the presence or absence of blood in the sinuses.

Animals↗
PubMedDate not supplied

The effect of trans-stifle external skeletal fixation and hyaluronic acid therapy on articular cartilage in the dog.

Transarticular external skeletal (TES) fixators were applied unilaterally to the stifle joints of 10 young adult dogs. After 4 weeks, the fixators were removed from all dogs. Two dogs were not allowed a remobilization period, whereas 8 dogs were provided with 4 additional weeks of weight-bearing activity in a kennel run. Four dogs were given high-molecular weight hyaluronic acid by intra-articular injection weekly during the remobilization period. Clinical gait evaluations and range of motion were determined during the remobilization period. Articular cartilage samples from both stifle joints of all dogs were evaluated histologically and histochemically. No significant differences in gait scores or range of motion were noted between treated and untreated dogs. Articular cartilage proteoglycan content was reduced after 4 weeks of trans-stifle external skeletal fixation as determined by loss of alcian blue (AB) histochemical staining. Improved homogeneity of histochemical staining was observed after remobilization. However, remobilization was associated with histological damage to the surface and tangential layers of articular cartilage. Remobilization combined with hyaluronic acid (HA) therapy improved histochemical staining and reduced structural damage to articular cartilage when compared with remobilization alone.

Animals↗
PubMedDate not supplied

Histochemical localization of T-cells in tissue sections.

Utilizing the acid alpha-naphthyl acetate esterase histochemical staining technique, cells with established T-cell (thymus-derived) staining characteristics could be consistently demonstrated in the periarteriolar lymphatic sheaths of the spleen and the diffusely infiltrated area of the cloacal bursa. The same areas failed to stain positively in significant numbers following a preincubation period with a specific inhibitor for carboxyl esterase. Lymphoid cells in the thymus, the splenic follicles, and bursal follicles were mostly negative.

Animals↗