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Biomedical subjects

A Nyska

Publications and source records attributed to A Nyska.

At least 145 records · Page 8Linked to original sources
PubMed1989

Toxicity study in rats of a tellurium based immunomodulating drug, AS-101: a potential drug for AIDS and cancer patients.

Male and female Sprague Dawley rats were injected intraperitoneally for 4 weeks with ammonium trichloro (dioxyethylene-0-0'-) tellurate, an immunomodulating drug at doses ranging from 3 to 24 mg/kg/week. Routine laboratory examinations included body weight, food consumption, clinical chemistry and hematological examinations. At termination of the experiment, all rats were sacrificed and subjected to a detailed necropsy. Few mortalities were recorded during the course of the study. Clinical signs included hind limb paresis and paraphimosis. A garlic odor pervaded the room. Body weight and food consumption were adversely affected in a dose-related manner. Effects were elicited on the hematological system; changes being noted in the platelet and leukocyte counts as well. Clinical chemistry evaluation revealed signs of hepatoxicity, especially in the female treated groups. The level of beta-globulin was increased. At necropsy organs were found to have a grayish-blue discoloration. Tellurium related histopathological changes were observed in the eyes, liver, thymus, bone marrow, heart and kidneys. An attempt has been made to compare the toxicity of this drug with other tellurium-containing compounds. A good correlation was found. Novel effects of the drug were retinopathy and replacement of bone marrow by bony or fibrous tissue. The possibility that some of the effects may have been elicited due to selenium-vitamin E deficiency has been considered.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Effect of swimming on bone growth and development in young rats.

The effect of chronic swimming on bone modelling was studied. Forty female Sabra rats (5 weeks old) were randomly assigned to the following experimental groups: 30 rats were trained to swim (water bath 35 +/- 1 degree C, one h daily, five times a week) for 20 weeks--20 of them loaded with lead weights (1% body weight) while the rest (10 animals) swam load free. Ten sedentary rats matched for age and weight served as controls. At the end of the twenty-week swimming period, all rats were sacrificed, both humeri bones were dissected and prepared for the following examinations: morphometric, bone density (BD), bone mineral content (BMC), compression tests and cross-sectional geometrical parameters, histomorphometry and biochemical analysis of minerals (Ca, Pi, Mg, Zn). All measured parameters were found to be significantly higher (P less than 0.05) in the swimming rats irrespective of load, as compared with the controls. Bone weight was higher by 19%, bone volume by 11%, bone length by 2.8%, cortical area by 16%, BD by 7% and BMC by 15%. The compression breaking force at the distal shaft of the humerus was higher by 24% in the trained group, while the ultimate compressive stress was not significantly different. Maximal and minimal moment of inertia at the distal diaphysis were 33.4 and 40% higher, respectively, for the swimming groups than the controls. Ca, Pi, Mg and Zn levels per total humeral bone were significantly higher in the exercising rats. The histomorphometry and cross-sectional data emphasize longitudinal and transversal growth. These data indicate that swimming exercise exerts a positive effect on bone growth and development in young rats.

Animals↗
PubMed1989

Abortifacient potential for the epigeal parts of Peganum harmala.

The effect of methanol and acetone extracts of the epigeal parts of Peganum harmala, a common medicinal plant among Bedouins in Israel, was studied on several parameters of reproduction in female rats. The methanol extract at a dose of 2.5 g/kg/day, offered in food or in drinking suspension for 30 days, significantly prolonged diestrus by 1.0 day. The methanol extracts at doses of 2.0, 2.5 and 3.5 g/kg/day appeared to produce a dose-dependent significant decrease in litter size. No change in the physical and nutritional status of the animals and no adverse toxicological effects were observed.

Abortifacient Agents↗
PubMed1989

Ankle extensor tendon synovitis due to a date palm thorn.

Palm thorn injury to tendons and joints is characterized in most patients by an acute inflammatory stage followed by a relatively asymptomatic period and finally by chronic synovitis or tenosynovitis. Once the inflammatory process has begun, detection and localization of the thorn can be very difficult. We present an unusual case of palm thorn tenosynovitis of the ankle extensor tendon which was detected and localized preoperatively by ultrasound. Removal of the thorn and synovectomy were curative.

Adult↗
PubMed1989

Quantitative evaluation of chlortoluran-induced splenic hemosiderosis by means of an image analyzer.

This study investigated a technique for the quantification of hemosiderin layed down in the spleen. The model used was the rat to which the urea-based herbicide chlortoluran was fed for 90 days. There was good correlation between hematological, biochemical, histological and image analytical techniques when splenic hemosiderosis was of a moderate to severe degree. Where hemosiderosis was of a slight nature, only the technique of image analysis was able to detect the on-going changes.

Animals↗
PubMed1989

The renal carcinogenic effect of Merpafol in the Fischer 344 rat.

Three groups of Fischer 344 rats were fed Merpafol (Makhteshim, Israel), an agricultural fungicide, in increasing concentrations for a period of 2 years. A control group was maintained under identical conditions, but without the addition of the fungicide in the diet. A range of nonneoplastic and neoplastic lesions were observed in the kidneys of rats fed Merpafol. The histogenesis of the renal tumors is discussed in relation to chemical-induced epithelial hyperplasia and cystic tubular dilation. Comparative aspects of renal cyst development and carcinoma in humans are also discussed.

Adenoma↗
PubMed1988

Cryptococcosis of the nasopharynx in mice and rats.

An attempt to infect the upper respiratory tract of mice and rats with various bacteria and fungi by intranasally instillation was performed. Cryptococcus neoformans was the only agent to invade the tissue. The infection was limited to the nasopharynx, a phenomenon which probably indicates the presence of a specific chemotaxis or receptor.

Animals↗
PubMed1988

Effect of prostaglandin and leukotriene antagonists in acute mesenteric artery occlusion.

Superior mesenteric artery occlusion leads to mesenteric ischemia, activation of arachidonic acid metabolism and release of endotoxins into the systemic circulation. The effect of leukotriene and prostaglandin antagonists on hemodynamic response and survival of rats after superior mesenteric artery (SMA) occlusion was investigated. The animals were divided into five groups: in group 1 (n = 105) the SMA was clamped for 2 h and mortality assessed after 24 h. Group 2 animals (n = 20) were pretreated with 5 mg/kg indomethacin and the SMA clamped similarly to group 1, group 3 animals (n = 15) were pretreated with 5 mg/kg Voltaren, group 4 animals (n = 20) received 20 mg/kg BW 755C before mesenteric artery occlusion, and group 5 animals (n = 50) were pretreated with 100 mg diethylcarbamazine. The blood pressure and pulse response as well as histologic appearance of the bowel 1 h after declamping was similar in all five groups. The mortality rate after 24 h was 34% in the control group, 36% with indomethacin treatment, 36% with voltaren, 47% with BW 755C and 40% with diethylcarbamazine. The mortality rate in all the treated groups was not significantly different from the control group. Plasma thromboxane B2 levels were inhibited significantly by indomethacin and Voltaren and to a lesser extent by BW 755C. There was a paradoxical rise in thromboxane B2 following diethylcarbamazine treatment. It is concluded that inhibition of the cyclooxygenase and/or the lipoxygenase pathways of arachidonic acid did not alter the hemodynamic response and mortality following 2 h of acute superior mesenteric artery occlusion.

Acute Disease↗
PubMed1988

Gingival hyperplasia in dogs induced by oxodipine, a calcium channel blocking agent.

Subchronic oral exposure of dogs to Oxodipine, a new calcium channel blocker of the dihydropyridine-type, resulted in dose-related gingival hyperplastic changes. The doses at which an effect was elicited were 24 and 73 times the intended therapeutic dose for man. The effects were first noted after 7 weeks of treatment, and were limited to the high and intermediate dose groups of both sexes. Macroscopically, a generalized enlargement of the maxillary and mandibular facial and lingual gingivae were noted. The histological changes were similar to those described in man for Nifedipine and hydantoin-related drugs. An increase in the activity of alkaline phosphatase and a decrease in alanine aminotransferase was demonstrated. This article is the first to describe gingival hyperplasia in dogs induced in a dose-dependent manner by a calcium channel blocker.

Alanine Transaminase↗
PubMed1988

Thyroxine (T4) and triiodothyronine (T3) levels in the Fischer 344 inbred rat.

Plasma levels of T3 and T4 were measured in male and female Fischer 344 (F344/Cr1) inbred rats aged 10, 17, 30, 56, 80 and 106 weeks in order to document the hormone profile of this strain of rat. In general, levels of T4 were higher in males than in females. Levels of T3 were lower in females for the first 17 weeks, similar for rats of age 30 weeks, and thereafter higher in the females than the males. T4 concentration decline was age-associated in both sexes. T3 levels declined in the males only, but remained relatively constant in the females throughout their lifespan. Generally, T4/T3 ratios declined throughout the lifespan of the Fischer rat.

Aging↗
PubMed1987

Decreased adhesion formation in flexor tendons by topical application of enriched collagen solution--a histological study.

In order to improve gliding function of damaged flexor tendons in chickens, we topically applied enriched collagen solution (ECS) to the tendon sheaths of severed tendons. Previous studies using the same experimental model showed improvement of gliding function in the damaged tendons biomechanically and increased collagenolytic activity in the area of the damage after application of ECS. In the present study we evaluated the influence of ECS on peritendinous adhesion formation and on the healing process of the tendons histologically. We found that topically applied ECS reduced adhesion formation, mostly during the first week, without adversely affecting tendon healing or scar maturation.

Administration, Topical↗
PubMed1987

Epidermoid cysts in the central nervous system of mice.

Two epidermoid cysts are described in mice, one intracranial, in the fourth ventricle and the other in the thoracic spinal canal. They were lined by compressed squamous epithelium and contained keratinaceous squamae. These incidental findings suggest that such cysts might be detected more often if more extensive examinations of the CNS were carried out in group studies.

Animals↗
PubMed1986

The effects of cold upon bone growth: a preliminary study.

The effects of various degrees of cold injury upon bone growth were experimentally studied. Young rabbits' feet, rendered ischemic by the application of a tourniquet, were cooled down by immersion in either an ice bath at 0 degrees C or an alcohol bath at -20 degrees C. The bone injuries were assessed clinically, radiologically, and histologically. Prolonged exposures to low temperatures above freezing do not cause any bone damage. Brief exposures to temperatures between -20 degrees C and -15 degrees C affect bone growth by inducing premature arrest of the epiphyseal plate, destruction of the epiphysis, and reactive-endosteal and periosteal bone formation. These effects lead to a statistically significant shortening and widening of the affected bones, which can be demonstrated radiologically. Low temperatures have a primary direct lethal effect upon the highly sensitive chondrocytes of the epiphyseal growth plate. Bone damage is independent of associated soft-tissue injuries and not linked to frostbite of the extremity or to solidification of tissues.

Animals↗