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Biomedical subjects

A Nyska

Publications and source records attributed to A Nyska.

At least 73 records · Page 4Linked to original sources
PubMed1997

A new retroviral AIDS-like disease and/or acute leukemia induced in mice by alloimmune stimuli.

We have shown a new phenomenon demonstrating that BALB/c female mice mated to C57BL/6 males during a year (7-10 pregnancies) develop AIDS-like disease or acute leukemia after an additional immunization with fixed ConA activated paternal (C57BL/6) lymphocytes. The AIDS-like disease is sexually and vertically transmissible and easily transferable to intact BALB/c and C57BL/6 mice by filtered plasma of affected animals.

Acquired Immunodeficiency Syndrome↗
PubMed1996

In vivo and in vitro toxicity of newly synthesized monofunctional sulfur mustard derivatives.

The toxicity of two new monofunctional sulfur mustard derivatives was tested. The compound (4-carboxybutyl 2-chloroethyl sulfide, CBCS; 10-carboxydecyl 2-chloroethyl sulfide, CDCS) possess the 2-chloroethyl sulfide moiety present in mustard gas. Exposure of guinea pig skin to CBCS resulted in a dose-related ulcerative effect. CDCS exhibited similar pathological effects. Dimethylsulfoxide (DMSO) exacerbated CBCS toxicity. Regeneration and healing were prominent six days after application. Concentration-related effects were found in in vitro systems, using human SH-SY5Y neuroblastoma cells for acute toxicity and Y79 retinoblastoma cells for colony forming assay. CBCS or derivatives may serve as models compounds for investigating the mechanism of action of alkylating agents.

Administration, Topical↗
PubMed1996

Differing proliferative responses in proximal and distal colons of growing rats fed food eaten by adenoma patients.

Animal dietary studies related to human colorectal carcinogenesis are usually based on AIN-76A diet, which is dissimilar to human food in source, preparation, and content. Our aim was to examine colonic epithelial proliferation in rats fed a diet based on the mean daily food intake of adenoma patients. Foods were prepared as reported by the adenoma patients and dehydrated; 64 Sprague-Dawley rats were fed either "human adenoma" or AIN-76A diet and every eight weeks, eight from each group were sacrificed. Both groups gained weight equally, had no colonic histological changes, but during the study showed progressive lengthening of colonic crypts (P < 0.01) and decreased proliferation (P < 0.05) in distal colons. Compared to controls, rats fed human adenoma diet had significantly longer crypts (P < 0.01) and more labeled cells (P < 0.05) at 32 weeks; overall they had increased proliferation (P < 0.01), most significantly in the distal colon. Thus, food eaten by adenoma patients induced hyperproliferative changes in the rat colon during growth and maturity, especially the distal colon, as found in humans at risk for neoplasia.

Adenoma↗
PubMed1996

Skin tumours in cattle and sheep after freeze- or heat-branding.

This article describes the occurrence of carcinogenic epidermal neoplasia (papillomas and squamous cell carcinoma) at the sites of tattooing with liquid nitrogen in dairy cattle, and squamous cell carcinoma at the sites of freeze- or heat-branding in beef cattle and sheep.

Animal Identification Systems↗
PubMed1996

Brain effect of intracarotid administration of cisplatinum.

The antitumoral effect of Cisplatinum is well known, including its effect on brain tumors. With the purpose of establishing the effect of intraarterial cis-dichlorodiammine platinum (CDDP) on the brain, Cisplatinum was injected in rabbits that were sacrificed at different intervals. The general clinical and neurological condition of the rabbits was unaffected, and histopathological examination of the rabbit's brain was normal.

Animals↗
PubMed1996

Effect of the combination of cisplatinum and radiation in the rabbit's brain.

The effect of cisplatinum as a potential radiosensitizer in brain tumors is controversial. We examined the effect of the combination of cisplatinum with radiation compared to radiation alone in rabbits' brain. All rabbits were irradiated and cisplatinum was injected intravenously into part of them. Therapeutic doses of cisplatinum and irradiation were given. The rabbits were euthanised at different intervals according to protocol. The general clinical and neurological condition of the rabbits was unaffected, and histopathological examination of the rabbit's brain was normal. The purpose of this study was to establish the effect of cisplatinum followed by cranial irradiation in therapeutic doses to the normal rabbit's brain.

Animals↗
PubMed1996

Topically applied halofuginone, an inhibitor of collagen type I transcription, reduces peritendinous fibrous adhesions following surgery.

To test in vivo the effect of previously observed inhibition of collagen type I transcription by the plant alkaloid Halofuginone, deep flexor tendons of 12 chickens were severed and sutured, and Halofuginone was applied topically at the site of surgery. Intact tendons, and severed but untreated tendons served as controls. The effect of the treatment was assessed by histological, biochemical, and biomechanical examinations of the operated and intact tendons three weeks after surgery. The results indicated an almost complete absence of fibrous peritendinous adhesions in the histologic sections of the Halofuginone treated tendons. There was a statistically significant decrease in collagen contents of and in both force and energy required to pull out the Halofuginone treated tendons from their sheath, relative to the untreated controls. Halofuginone had no effect on the cellularity of the healing tissue. We conclude that Halofuginone is a potent inhibitor of fibrous peritendinous adhesions with potentially important clinical applications.

Animals↗
PubMed1996

Sarcoptic mange in wild ruminants in zoological gardens in Israel.

Sarcoptic mange (Sarcoptes scabiei) occurred among wild ruminant species in five zoological gardens in Israel, from 1984 to 1994. Infestation of five ruminants by S. scabiei is reported for the first time: mountain gazelles (Gazella gazella), Nubian ibexes (Capra ibex nubiana), a barbary sheep (Ammotragus lervia), elands (Taurotragus oryx), and an Arabian oryx (Oryx leucoryx). All animals in the herds were administered ivermectin orally at a dose of 200 micrograms/kg body weight daily for 3 consecutive days. This was repeated three times at 2-wk intervals. The disease was eradicated in four small zoos, whereas in the biggest zoo, only control was achieved. Mortality among animals < 4 mo and > 8-yr-old animals composed 65% of mortality among all age classes.

Administration, Oral↗
PubMed1996

Immunohistochemical study of pancreatic neuroendocrine tumor in Panthera tigris tigris.

The histological and immunohistochemical characteristics of a case of pancreatic neuroendocrine tumor are described in a 14-yr-old female Bengal tiger (Panthera tigris tigris) housed at the New Biblical Zoo of Jerusalem, Jerusalem, Israel, 1994. The neoplastic cells were immunohistochemically negative for insulin and glucagon, slightly positive for neuron-specific enolase, moderately positive for serotonin and somatostatin, and markedly positive for chromogranine A and gastrin. This is the first documentation of a pancreatic neuroendocrine tumor in the tiger.

Animals↗
PubMed1996

Treatment of experimental inflammatory synovitis with continuous magnetic field.

The effect of a magnetic field on synovitis in rats was studied. Synovitis was induced by bilateral intraarticular injection of zymosan to the hind joints. One group of rats was held in a cage with a magnet of 3,800 Gauss on the bottom of the cage (treated), while another group was held in a cage without a magnet (control). Three weeks following intraarticular zymosan injection all rats were killed and the hind joints tissues were examined histologically. The pathologic process was noted and graded according to the involvement of various tissue components, number of inflammatory foci, and size of the lesion. The histologic findings of the tissues from the control group consisted of marked articular infiltrate, composed of lymphocytes and plasma cells with some histocytes in 80% of the animals. A small articular infiltration of the same nature was observed in 20% of the treated rats. The inflammatory score was 3.4 +/- 1.1 in the treated animals and 6.8 +/- 2.6 in the control group (P = 0.002). These data showed that synovitis and the inflammatory process are significantly suppressed by a magnetic field.

Animals↗
PubMed1996

Occurrence of cowpox-like lesions in cattle in Israel.

Two different clinical forms of cowpox infection, which occurred sporadically in one dairy herd and one beef herd, are described. The agent was identified by virologic test and by electron microscopy, when a characteristic orthopoxvirus was noted. No systemic illness was diagnosed with any of the two forms and recovery was observed in 3-4 weeks. The epizootiology of the infection is discussed.

Animals↗
PubMed1995

Changes in intestinal tunica muscularis following dietary fiber feeding in rats. A morphometric study using image analysis.

The morphological changes in the intestinal tunica muscularis induced by prolonged dietary fiber intake were determined in rat small intestine and colon with the aid of computerized image analysis. Thirty male Sprague-Dawley rats were fed either a fiber free, 15% cellulose or 15% pectin diet for 8 weeks. Intestine length was measured and stained cross sections of the jejunum, ileum, and colon were quantitated using image analysis. In the distal colon, muscle cell size was also determined. Despite lower weight gain in the pectin fed rats, both the small intestine and colon length were significantly increased. Cellulose feeding had a lesser effect on intestine length. Pectin fed rats had significantly increased relative tunica muscularis area (37.2 +/- 2.2 mm2) in ileum cross sections when compared to control (24.3 +/- 1.8 mm2) and cellulose fed rats (26.1 +/- 1.1 mm2). In the mid-colon, the tunica muscularis area was found to be pectin > cellulose > control (33.5 +/- 2.2; 29.7 +/- 1.7; 25.8 +/- 1.5 respectively) with significant differences reached between pectin and control rats. In jejunal samples, no differences were observed among the groups. Circular smooth muscle cell size in the distal colon was significantly increased following cellulose feeding but was less pronounced in the case of pectin. We conclude that fiber supplementation leads to morphological changes in the rat intestine including changes in length and tunica muscularis volume.

Animals↗
PubMed1995

In vitro effect of ciprofloxacin on HT-29 human colon carcinoma cell line: assessment of cell proliferation by thymidine uptake and silver nucleolar organizer regions (AgNOR) histomorphometry.

In an in vitro study, the effect of ciprofloxacin was examined on proliferation of HT-29 human colon carcinoma cell line. Cell proliferation was measured by 3H-thymidine uptake and silver nucleolar organizer region (AgNOR) histomorphometry. A significant increase in [3H]thymidine incorporation (p < 0.05) parallel with a significant increase in the mean AgNOR clusters/cells (p < 0.01) was noted after 5 days of cell exposure to ciprofloxacin. It is suggested that the assessment of AgNOR variables is useful in examination of quinolone effect on HT-29 human colon carcinoma cell proliferation.

Carcinoma↗
PubMed1995

Investigation of potential oncogenetic effects of beta-cyclodextrin in the rat and mouse.

The results of oncogenicity studies of beta-cyclodextrin in inbred Fischer 344 rats and CD-1 outbred mice are presented. Chronic feeding of beta-cyclodextrin to Fischer 344 rats and CD-1 mice did not cause any treatment related carcinogenic effects. The only toxic effect was seen in mice as macroscopic distension of the large intestine with soft or fluid contents, histologically associated with the mucosa covered by mucous secretion containing exfoliated cells, and mucosal flattening and intestinal gland atrophy. Despite these observations, no differences between control and treated groups were observed concerning mortality, clinical observations or body weight and food consumption.

Animals↗
PubMed1995

Correlation of Ag-NOR protein measurements with prognosis in canine transmissible venereal tumour.

Ten canine transmissible venereal tumour (TVT) cases were studied by digital image analysis quantification on sections stained with silver to demonstrate nucleolar organizer regions (Ag-NORs). In each animal, 100 neoplastic cells were randomly selected for evaluation. The following parameters were measured or calculated: area of nucleus, area of Ag-NOR dot, the mean number of Ag-NOR dots per nucleus, the mean area of Ag-NOR dots per nucleus and the ratio of mean nuclear dot area to nuclear area. All 10 cases were treated with vincristine at a dose of 0.6 mg/m2 intravenously once a week. Two, which showed malignant characteristics (i.e. uncontrolled growth, local invasion or metastasis), did not respond to multiple (12) treatments and had a fatal outcome. Of the remaining eight cases, seven responded to two to six treatments and one required 12 treatments. The average number of Ag-NORs per nucleus and the area of Ag-NORs per nucleus were lower in the seven cases that responded to two to six treatments than in the other three cases, but the difference was not significant. However, there was a significant difference in the ratios of Ag-NOR area to nuclear area between the two groups of cases. Thus, poor prognosis was (1) possibly correlated with an increase in the mean number of Ag-NORs per nucleus and an increase in the mean area of Ag-NORs per nucleus, and (2) definitely correlated with an increase in the mean ratio of Ag-NOR area to nuclear area.

Animals↗