Biomedical subjects
Publications and source records attributed to J Osman.
Naftidrofuryl enhances oxidative phosphorylation and might therefore be expected to improve exercise tolerance and breathlessness in advanced chronic bronchitis. This hypothesis was tested in a four-week placebo-controlled trial in 11 bronchitic patients. Seven patients completed the study. There was no evidence of any benefit from naftidrofuryl either subjectively or after a 12-minute walking test.
We describe 13 patients with legionnaires' disease in Nottingham, all presenting with lobar pneumonia. Six patients required artificial ventilation and 2 died. No common source of infection has yet been identified, but the disease appears to be prevalent and possibly endemic in this city.
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Selective dopamine receptor antagonists have been shown to reduce food intake of rats under such regulatory challenge conditions as food deprivation and 2-deoxy-D-glucose-induced glucoprivation, and under such palatable conditions as acute exposure to sucrose solutions. Food intake is increased following either pretreatment with the free fatty acid oxidation inhibitor, mercaptoacetate (MA), or acute exposure to a palatable high-fat source. The present study examined whether equimolar doses (50-800 nmol/kg, s.c.) of either the selective D(1) receptor antagonist, SCH23390, or the selective D(2) receptor antagonist, raclopride, would alter food intake elicited by either MA (70 mg/kg, i.p.) or acute exposure to a high-fat diet (67% ground rat chow, 33% vegetable shortening). SCH23390 significantly and dose-dependently reduced MA-induced feeding with the two higher (400 and 800 nmol/kg) doses eliminating this response after the first 2 h and the two lower (50 and 200 nmol/kg) doses preventing the occurrence of significant MA-induced feeding. Raclopride eliminated MA-induced feeding at the highest dose, and produced dose-dependent reductions at lower doses. A different pattern of dopamine antagonist effects emerged for high-fat intake. The identical dose range of SCH23390 failed to alter high-fat intake. In contrast, whereas the highest (800 nmol/kg) dose of raclopride significantly reduced high-fat intake after 1 h, the middle (200 and 400 nmol/kg) doses of raclopride significantly increased high-fat intake after 2 h. These data are discussed in terms of the modulatory actions of dopamine upon food intake, of the differential actions of dopamine receptor subtypes upon intake under challenge and palatable conditions, and of the potential participation of presynaptic and postsynaptic receptor populations in these responses.
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Serological investigations were performed in order to establish the antigenic relationships between three Chlamydia strains: T44(subgroup A), T13 and Q18 (subgroup B). By using monospecific mouse immune sera a certain degree of antigenical relationships was made evident and the strains could be typed by microagglutination and microimmlnofluorescence reactions. Similar results were obtained by seroneutralization with hyperimmune sera prepared in the rooster. Complement fixation proved to be a group-specific reaction unable to reveal significant differences between the strains studied, not even with monospecific mouse sera. The antigenic relationships established between strains T44 (trachoma) and T13 (psittacosis) suggest the existence features common to subgroup A and B Chlamudia strains. The importance of typing Chlamudia strains with a view to specific prophylaxis is emphasized.
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A vaccine against chlamydial ovine abortion was prepared according to an original method and experimentally applied to more than 500,000 animals in large breeding units. The vaccine induced a considerable seroconversion (as demonstrated by complement fixation tests) and reduced by 3--5 times the damage due to chlamydioses. Vaccination of primiparous ewes, followed by 2--3 annual revaccinations, gave good results, conferring resistance on the vaccinated animals.
The authors establish the optimal conditions (protein concentration, temperature) for the coupling of purified mycoplasma antigen to sheep red blood cells, in order to obtain an antigenic complex stable for at least 1 year. This comples allows specific determination by passive hemagglutination--a simple and rapid technique--of anti-mycoplasma antibodies in the sera of men or animals suspected of mycoplasma infections. Under the stated experimental conditions, antibody titers equal to or higher than 1/128 indicate an infection with M. pneumoniae.
In order to evaluate the efficiency of passive hemagglutination (PHA) and complement fixation (CF) tests for the diagnosis of M. pneumoniae infections, 144 serum samples--out of which 81 from patients with respiratory and cutaneous infections and 63 from subjects with other diseases (controls)--were comparatively investigated by the two methods. The PHA test made evident a positivity index of 65% in the case of mixed pneumonias, as against 17% in controls, while the results obtained by CF were almost identical in the two groups investigated. The high specificity and sensitivity of the PHA reaction recommend this method for the diagnosis of acute M. pneumoniae infections.