Biomedical subjects
Publications and source records attributed to M R Anver.
Five cases of amebiasis were diagnosed in goldfish (Carassius auratus) from home aquariums and from a laboratory aquarium. Granulomas containing amoebae were in many organs but were most numerous in kidneys. Because there were pseudopods, food vacuoles, vesicular nucleoli and other ultrastructural characteristics of the organisms, we identified the organisms as amoebae. On the basis of mitotic stages it is possible they belong in the family Hartmannellidae.
Mycobacteriosis in a Phrynops hilari (side-necked turtle) was characterized by multiple caseating granulomas in the liver and spleen; pulmonary involvement did not occur. Granulomatous inflammation and organisms also were present in the skin, suggesting a cutaneous route of entry with hematogenous spread to visceral organs. Review of the four cases of chelonian mycobacteriosis in the literature indicated that pulmonary tubercules and plastral ulcerations are typical manifestations. The Mycobacterium species usually involved is M. chelonei.
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Dermatophilus congolensis was isolated from cutaneous hyperkeratotic nodules of two marble lizards. The organism was similar to strains of D congolensis previously characterized as mammalian pathogens. The isolate was experimentally transmitted to other marble lizards and to Spb:(SW)BR mice by subcutaneous inoculation and by topical application after skin scarification.
The significance of fever in response to a bacterial infection has been investigated using the lizard Dipsosaurus dorsalis as an animal model. These lizards develop a fever of about 2 degrees C after injection with the bacterium Aeromonas hydrophila. To determine whether this elevation in body temperature increases the resistance of the host to this infection, as measured by survival, lizards were infected with the live bacteria and placed in a neutral (38 degrees C), low (34 degrees or 36 degrees C), or high (40 degrees or 42 degrees C) ambient temperature. An elevation in temperature following experimental bacterial infection results in a significant increase in host survival.
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Explore the source record for details and available documents.
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Sodium tetradecyl sulfate 3% (Sotradecol) was perfused into a proximally obstructed renal artery in ten random-source adult dogs. In all animals, the intra-arterial injections of Sotradecol produced immediate thrombosis of the renal arteries. Angiographic studies, lasting up to ten weeks, on eight dogs demonstrated persistent occlusion. In one dog, unintentional thrombosis occurred in the opposite renal artery due to reflux of Sotradecol. Histopathologic studies showed total obliteration of the renal arteries through organized thrombosis, intimal sclerosis, and luminal collapse. In all dogs, the kidneys were not visible, and diffuse renal infarction was confirmed by histologic studies of five dogs.
Protein C is a vitamin K-dependent serine protease with anticoagulant and profibrinolytic activity which is synthesized in the liver. Decreased protein C activity was detected in a Thoroughbred colt with clinical and histopathologic evidence of recurrent venous thrombosis. Although protein C activity was reduced, protein C antigen concentration was normal. Consumptive coagulopathies produce a decrease in both the functional and antigenic concentrations of protein C, thus a defect in protein C synthesis was suspected. Inhibition of gamma-carboxylation secondary to vitamin K antagonism results in the synthesis of a protein C molecule with antigenicity, but without biological activity. However, there was no evidence of vitamin K antagonism. The hypercoaguable state resulting from the reduced activity of protein C in this colt was associated with uncomplicated renal disease, rather than a protein C consumptive process such as endotoxemia. A primary hypercoagulable state due to a deficiency of protein C activity was diagnosed. Primary deficiencies of protein C activity have not been previously documented in horses.
BACKGROUND: It is generally accepted that P-glycoprotein 170 (MDR1/Pgp170) expression in breast tumors results in poor response to chemotherapy due to its ability to export chemotherapeutic agents. Studies indicate that the use of non-steroidal anti-inflammatory drugs (NSAIDs) may enhance the anti-tumor activity of cancer chemotherapeutic agents and reduce the risk of many cancers. The best known function of NSAIDs is to block the enzyme cyclooxygenase (Cox), the rate limiting enzyme in the conversion of arachidonic acid to prostaglandins. In this study we investigated whether expression of the inducible isoform of Cox (Cox-2) is linked with the multidrug resistance phenotype in breast cancer. METHODS: Expression of Cox-2 and MDR1/Pgp170 was investigated in tumor specimens along with normal epithelium in breast cancer patients using immunohistochemisrty. Expression of Cox-2, MDR1/Pgp170, Protein Kinase C (PKC), and Activator Protein 1 (AP1) were investigated in a series of increasingly resistant human MCF-7 breast cancer cells compared to wild type using immunohistochemistry, Western blots, Northern blots, RT-PCR, and Southern blots. RESULTS: Immunohistochemical analyses of human breast tumor specimens revealed a strong correlation between expression of Cox-2 and MDR1/Pgp170. In drug resistant cell lines that over-express MDR1/Pgp170 there was also significant up-regulation of Cox-2 expression. In addition, PKC and AP1 subunits c-Jun and c-Fos were also upregulated. We hypothesized that increased prostaglandin production by Cox-2 induces PKC and the expression of transcriptional factor c-Jun, which in turn, induces the expression of MDR1/Pgp170. CONCLUSION: We propose that pretreatment with selective Cox-2 inhibitors may be useful in the prevention of multidrug resistance in response to cancer chemotherapy and should be further evaluated.
Anuran and urodele amphibians develop spontaneous neoplasms in all major organ systems with the integumentary system a frequent target. Anurans and urodeles have spontaneous viral-associated tumors, the biological behavior of which is temperature-related. Anurans seem to have a greater frequency of spontaneous neoplasms than do urodeles and respond to chemical carcinogens in a manner analogous to mammalian species. Urodeles have greater cell regenerative capabilities than do anurans and paradoxically, are more refractory than anurans or mammalian species to chemical carcinogens in their proliferating regenerative blastema.
Goldfish (Carassius auratus) were exposed to outboard exhaust products in water or to toluene (a constituent of outboard motor exhaust water) via a continuous flow bioassay dosing apparatus. Various physiologic and pathologic changes were noted. In the blood a consistent decrease (p less than 0.05) in the partial pressure of oxygen, a significant increase (p less than 0.05) in the partial pressures of carbon dioxide, and significant decreases (p less than 0.05) in pH and oxygen saturation were found in many of the blood gas experiments. Laboratory experiments also indicated that these fish are capable of metabolizing toluene to hippuric acid (p less than 0.05). Exposure up to 30 days to these exhaust products produced gross and microscopic lesions in the high-, intermediate-, and low-dose fish. Grossly, livers were smaller and pale; intestines were empty of ingesta and feces; and gills were coated excessively with mucus. Microscopically, the livers of the exposed fish had a decreased cytoplasmic:nuclear ratio, gill filaments were fused, and some kidneys had tubular vacuolization.