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Biomedical subjects

M Afzal

Publications and source records attributed to M Afzal.

At least 91 records · Page 5Linked to original sources
PubMed1990

Effect of reactor retention on the spread of brucellosis in Jersey cattle and buffalo herds.

The rate of spread of bovine brucellosis was investigated in buffalo and Jersey cattle herds maintained at a Livestock Research station in Pakistan. Reactor animals (identified by conventional serological tests) were either retained or culled because of advanced age or poor productivity. Reactors were housed, managed and fed separately from the rest of the herds. The initial seroprevalence of brucellosis among both the Jersey cattle and the buffalo tested was 21.4%, the difference being statistically insignificant (p = 0.218). For 34 months, the spread of brucellosis was limited to 25 new reactors in the 334 cows and 33 in the 442 buffaloes. The mean attack rate was 7.5% for both herds during the test intervals. Trend analysis of proportions positive at each testing revealed a significant decrease in the percentages observed at the first testing. The management practice of segregation offered some advantage in reducing the spread of brucellosis to negative animals. However, an epidemiological study covering a large number of herds would be required to identify risk factors responsible for perpetuating the disease.

Animals↗
PubMed1989

Effect of paraquat administered intraperitoneally on the nonpolar lipids of rabbits.

Rabbits were injected intraperitoneally with 3, 6, or 12 mg of paraquat/kg/day for a period of 3, 7, or 14 days. Rabbits receiving 3 or 6 mg of paraquat/kg/day showed a significant loss of body weight at 7 days of the treatment. Liver, kidney, heart, and lungs demonstrated a significant decrease in their weights in the first 3 days of paraquat treatment. A decrease in total lipids, total triglycerides, and total cholesterol of both liver and kidney was observed. This decrease was accompanied by a significant increase in plasma total triglycerides and total cholesterol at 7 days of paraquat treatment. The ratio of cholesterol to cholesterol esters in liver decreased after 3 days of paraquat treatment after which it showed a consistent increase until the 14th day of the paraquat treatment. In kidney, this ratio increased for up to 7 days of paraquat treatment followed by a decrease at the 14th day. These results indicate, contrary to earlier reports, that rabbits are susceptible to paraquat toxicity.

Animals↗
PubMed1987

A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea.

A ninhydrin positive compound (L2) from commercially available unfermented dry green tea (Thea sinesis) leaves is found to be a potent inhibitor of thrombin-stimulated thromboxane formation in rabbit whole blood. Its potency is compared with caffeine, a member of the methylxanthines family. Both caffeine and L2 inhibit thromboxane formation in whole blood in a dose dependent fashion. L2 inhibition when calculated as I50 by a dose response curve is found to be more than 40 fold stronger than caffeine as an inhibitor of thromboxane formation. A concentration of L2 as low as 50 microM, suppresses thromboxane formation (by 84%) whereas a concentration of 5000 microM is necessary to achieve the same inhibition with caffeine. The potent inhibitory effect of L2 on the TXB2 production maybe of benefit in the treatment of vascular disease.

Animals↗
PubMed1987

Isolation and antigenic reactivity of Brucella ovis outer membrane proteins.

Brucella ovis cell membranes were isolated from fractured and lysozyme-treated cells by ultracentrifugation. These preparations appeared to consist largely of outer membranes, as judged from the results of ultracentrifugation experiments in sucrose density gradients under conditions that are widely used to separate inner and outer membranes of gram-negative bacteria. The sequential detergent extraction of cell membranes yielded mainly lipopolysaccharide and three groups of outer membrane proteins. In immunoblotting, lipopolysaccharide had good antigenic reactivity with all sera from rams exposed to B. ovis (vaccination or natural infection), but some outer membrane proteins reacted strongly only with sera from immune (vaccinated) rams, not from infected rams, suggesting a possible diagnostic role for such proteins in predicting immunity or infection.

Animals↗
PubMed1986

Lipid composition of the epidermal gel secretion from the Arabian Gulf catfish (Arius thalassinus Ruppell).

Lipids associated with a threat induced epidermal gel secretion from the catfish, Arius thalassinus, have been analyzed. Phospholipids, neutral lipids and glycolipids are all present and each of these subclasses has been analyzed by thin layer and gas chromatography with a general similarity with membrane lipids being noted. The epidermal gel lipids differed from total liver lipids of the catfish. Fatty acid analysis showed the gel lipid to be rich in the unsaturated fatty acids: oleate (omega 7, C18:1), arachidonate (omega 6, C20:4), and docosahexaenoate (omega 3, C22:6). Some prostaglandins were quantitated in lipid extracts from the epidermal gel.

Animals↗
PubMed1986

Immune response in rams experimentally infected with Brucella ovis.

Cellular as well as humoral immune responses were detected in six rams experimentally infected with Brucella ovis. Specific antibodies were detectable by enzyme-linked immunosorbent assay by day 11 after infection in all the rams. The levels of IgM antibodies and total antibodies in the serum rose until 33 and 41 days after infection respectively, then levelled off. Antigen-induced blastogenic responses by lymphocytes developed as early as five days after infection in all rams but had decreased to low levels by day 63 in most. Blastogenesis induced by phytohaemagglutinin and concanavalin A varied among infected rams and did not differ significantly (P greater than 0.05) from control rams. All rams had developed delayed-type skin hypersensitivity by day 63 after infection. One ram which did not become infected as a result of exposure had low levels of B ovis serum antibodies and a detectable antigen-induced lymphocyte blastogenic response before infection, suggesting the involvement of cell-mediated immunity in protection against B ovis.

Animals↗
PubMed1984

Protection of rams against epididymitis by a Brucella ovis-vitamin E adjuvant vaccine.

Rams vaccinated at 7 and 8 months of age with a B. ovis-vitamin E adjuvant vaccine had increased antibody titers compared with Freund's incomplete adjuvant or commercial bacterin vaccinated rams. The percent overall infectivity in an experimental infection of B. ovis-vitamin E adjuvant vaccinated rams was 22% compared to 44% for B. ovis-Freund's incomplete adjuvant or bacterin vaccinated rams and 67% for control.

Adjuvants, Immunologic↗
PubMed1984

Characterization of Brucella ovis lipopolysaccharide and its use for diagnosis of ram epididymitis by enzyme-linked immunosorbent assay.

Rough lipopolysaccharide, extracted by a mixture of phenol, chloroform, and petroleum ether from freeze-dried Brucella ovis cells with a yield of 0.71%, contained relatively small amounts of protein and nucleic acid contaminants as compared with lipopolysaccharides from other Brucellae. The crude lipopolysaccharide was suitable as a diagnostic antigen in an enzyme-linked immunosorbent assay for the sensitive and specific detection of ram epididymitis caused by B. ovis infection. In comparative serological tests, the enzyme-linked immunosorbent assay with B. ovis lipopolysaccharide gave better identification of infections and fewer false-negative results than the enzyme-linked immunosorbent assay with sonicated antigen or the complement fixation test.

Animals↗
PubMed1983

Streptomyces maghwi, a new species producing roflamycoin.

A new Streptomyces species is described for which the name S. maghwi is proposed. The organism is characterized by a pink mass of aerial mycelium, spiral spore chains, spores with smooth surfaces and a nonchromogenic vegetative mycelium. S. maghwi produces roflamycoin (Schlegel et al. 1981) formerly known as flavomycoin (Schlegel et al. 1971). The type strain of S. maghwi is deposited with CBS, Netherland.

Antifungal Agents↗