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Biomedical subjects

J A Moore

Publications and source records attributed to J A Moore.

At least 199 records · Page 11Linked to original sources
PubMed1978

Regional uptake of endogenous corticosterone by rat brain following stress.

The stress-induced changes in the corticosteroid levels in four brain regions were studied in female Sprague-Dawley rats using the fluorometric assay following column chromatographic separation. Fifteen min after novelty stress, the corticosteroid levels increased 1.5-, 1.5- and 1.7-fold in hippocampus, hypothalamus and cerebral cortex, respectively, compared to 6-fold increase in plasma (60 mug/d1). In the second study in which the animals were sacrificed 60 min after ethanol stress (I.P. injection of 2 g/kg in 20% solution with physiological saline), there were 2.5-, 3.5- and 4.7-fold increases in hypothalamus, hippocampus and cerebral cortex, respectively, compared to 4-fold increase in plasma (77 mug/d1). There were marked increases of corticosterone in the pituitaries after stress. The results confirm the differential regional distribution of corticosteroid in the brain and the stress-induced corticosteroid elevations. These results support the idea that the brain levels of corticosteroid are determined by the existing plasma levels and by the duration of the hormone elevation. The possible significance of the brain levels of corticosterone is discussed.

Animals↗
PubMed1977

Impairment of thymus-dependent immune functions by exposure of the developing immune system to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

The effects of TCDD exposure on the developing immune system were investigated in F344 rats. Fetal and neonatal rats were exposed to TCDD through maternal dosing (5 microgram/kg) on day 18 of gestation and on days 0, 7, and 14 of postnatal life (group I). Another group of neonatal rats was exposed to TCDD through maternal dosing on days 0, 7, and 14 of postnatal life only (group II). Body weights and thymus/body weight ratios were found to be suppressed up to 145 days of age in group I, but only up to 39 days of age in group II. Parameters of cell-mediated and humoral immune function were investigated. TCDD suppressed cell-mediated immune function without affecting humoral immune function. Suppression of T-cell function was selective in that "helper" cell function was not suppressed.

Animals↗
PubMed1976

Circadian rhythm of corticosterone in mice: the effect of chronic consumption of alcohol.

The effect of chronic consumption of alcohol on the circadian variations of the plasma corticosterone investigated in DBA/2J male mice. After 15 weeks of alcohol consumption (3.8%w/v for the first week and 7.5% for subsequent weeks) the alcohol groups exhibited a flattened circadian corticosterone curve, the level being intermediate between the peak and trough values of the water control groups. The diurnal patterns of food and liquid consumption were still present at the 10th week of alcohol treatment in the alcohol groups, although the absolute amount of food and liquid consumed at each of the 6-h intervals was somewhat different between the alcohol and water groups. The blood alcohol showed a peak at early morning with the mean of 100 mg/100 ml, but the levels of alcohol during the remaining periods were remarkably stable, the means ranging from 30 to 46 mg/100 ml. Chronic consumption of alcohol, even relatively low concentrations, appears to affect the neural sites in the CNS controlling the circadian rhythm of ACTH release.

Alcoholism↗
PubMed1976

Experimental biharzial bladder cancer: tryptophan metabolism in nonhuman primates experimentally infected with Schistosoma haematobium.

A nonhuman primate species infected with Schistosoma haematobium provided a model system for controlled studies on biharzial bladder cancer. Urinary excretion of tryptophan metabolites by capuchin monkeys (Cebus apella) was similar to that of humans when expressed per g creatinine. Liver tryptophan oxygenase activity of the capuchin monkeys was comparable to that of humans. Excretion of 3-hydroxykynurenine and 3-hydroxyanthranilic acid was elevated above control levels in capuchin monkeys infected experimentally with S. haematobium. The capuchin-S. haematobium system closely resembles the human biharziasis system and offers a reproducible laboratory model system for the controlled study of the parasitology, pathogenesis, and biochemistry of biharzial bladder cancer.

3-Hydroxyanthranilic Acid↗
PubMed1976

Immunologic response and factors affecting its assessment.

The potential harmful effects of toxic compounds on the developing immune system are discussed. This discussion is illustrated by results of studies of the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the developing immune system of Fischer rats. While this compound and several others have been shown to have immunosuppressive effects, the available data do not support routine evaluation of the consequence of chemical exposure to the developing immune system.

Animals↗
PubMed1976

Proliferative epithelial lesions of the urinary bladder in cynomolgus monkeys (Macaca fascicularis) infected with Schistosoma intercalatum.

Five cynomolgus monkeys (Macaca fascicularis) were infected with Schistosoma intercalatum, a helminth that is morphologically similar to Schistosoma haematobium. Infections were readily established and remained active until the monkeys were sacrificed 21 to 84 weeks after exposure. Although the schistosomes were located predominantly in mesenteric and hepatic portal venules, schistosome eggs were found in the bladders of 3 monkeys. Nodules of atypical epithelial cells interpreted as superficially infiltrating undifferentiated bladder carcinomas were found in one monkey 23 weeks after infection. These sessile tumors differ strikingly from the well-differentiated, papillary transitional cell tumors previously reported from several species of experimental animals infected with S. haematobium. The tumors are also dissimilar to the squamous cell bladder tumors associated with S. haematobium infection in man but may nonetheless be useful for investigations of schistosomal bladder cancer.

Animals↗
PubMed1975

Opossums as a reservoir for Salmonellae.

Approximately 200 opossums, trapped during the fall of 1973 in the vicinity of Raleigh, NC, were maintained in the Institute's breeding colony in individual cages until the breeding season. Clinically normal, dead, and moribund opossums were examined for Salmonella. Six serotypes of Salmonella were identified in both clinically normal and diseased opossums. Positive culture results were obtained on 39 of 56 (70%) rectal swab specimens collected in the fall from incoming opossums, and on 30 of 50 (60%) rectal swab specimens collected during midwinter from an additional group of clinically normal opossums, which were maintained in isolation for approximately 3 months before testing. At necropsy, 87 of 108 (81%) diseased opossums were culture positive for Salmonella. Salmonellae in serogroups B and R were isolated from the spleen, liver, kidneys, or heart blood as well as the ileum of 57 diseased opossums. In 23 cases, S typhimurium or S bern was isolated in pure culture from the visceral organs. These findings indicated bacterial septicemia. In contrast, salmonellae in serogroups C1, E1, and F were routinely isolated from the feces of clinically normal and diseased opossums, suggesting a habitat restricted to the intestinal tract and probably the mesenteric lymph nodes. It was concluded that the opossum serves as a reservoir for a number of serotypes of Salmonella and may have an important role in the epizootiology of wildlife salmonellosis.

Animals↗
PubMed1975

Calcification of the bladder and papillary tumours of the bladder and ureters in gibbons (Hylobates lar) infected with Schistosoma haematobium (Iran).

Many species of nonhuman primates have been employed to find parasite-definitive host combinations which would allow for investigations on different aspects of schistosomiasis haematobia. Gibbons (Hylobates lar), exposed to moderate numbers of Schistosoma haematobium cercariae, have demonstrated some of the basic features of schistosomiasis haematobia in man. Calcification in schistosomiasis haematobia is variable. Radiologically evident calcification of the bladder was noted in one gibbon. Radio-opaque areas in the bladder corresponded to dense deposits of calcified eggs observed on histological examination. Thus, it seems, bladder calcification, thought to be a later complication of schistosomiasis, can develop fairly rapidly. One of two gibbons killed 11 months after infection had small papillary transitional cell tumours in both ureters. The other had papillary transitional cell tumours covering most of the urinary bladder surface. No invasion of muscle by tumour was present and no metastases were seen.

Animals↗
PubMed1975

Increased susceptibility to bacterial infection as a sequela of exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The effects of subclinical levels of 2,3,7,8-tetrachloridibenzo-p-dioxin (TCDD) on the response of mice to infection with either Salmonella bern or Herpesvirus suis, also known as pseudorabies virus, are reported. TCDD is a contaminant of certain commercially useful chemicals, such as chlorinated phenols or herbicides. It has been shown to cause thymic atrophy and to suppress cell-mediated immunity in laboratory animals. Sublethal levels of TCDD were used: 0.5, 1,5, 10, or 20 mug/kg, given through a gastric tube once weekly for 4 weeks. A significant decrease in weight gain compared with control mice occurred at the 20-mug dosage. Dose schedules of 1 mug or more, followed by salmonella infection, resulted in significant increases in mortality and decreases in the time from infection to dealth. However, TCDD had no significant effect on mortality in the pseudorabies-infected mice. The most important finding in this study is that extremely low levels of TCDD, which do not produce clinical or pathological change, still have the capacity to affect host defense.

Animals↗
PubMed1975

Entopolypoides macaci Mayer, 1934 in the African baboon (Papio cynocephalus L. 1766).

Entopolypoides maaci occurs in different populations of Papio cynocephalus in Kenya, but not in the same host with Hepatocystis kochi. Parasitemia may be greatly enhanced by splenectomy, but there is little effect on the host in spite of substantial alteration in hemoglobin and RBC counts, and transferability to other primates is erratic. Descriptions are presented for differentiation of E. macaci from H. kochi.

Africa↗
PubMed1975

Experimental schistosomiasis haematobia in bushbaby (Galago crassicaudatus), Patas (Erythrocebus patas), and Grivet (Cercopithecus aethiops).

The bushbaby (Galago crassicaudatus), patas (Erythrocebus patas), and grivet (Cercopithecus aethiops) have been evaluated as hosts in experimental schistosomiasis haematobia. Individual hosts demonstrated considerable variation in host-parasite relationships. E. patas is suggested as a host for continuing investigations in Schistosoma haematobium infections, based upon its moderate susceptibility to infection and a moderate potential for pathological involvement of the urogenital system.

Animals↗