Biomedical subjects
Publications and source records attributed to S Pyakural.
Type O virus has been isolated from a natural outbreak of foot-and-mouth in Indian elephant. The history, symptoms and epizootology of this disease in these animals have also been described.
Enterotoxaemia in sheep due to Clostridium welchii type D was indicated by field and laboratory investigations in Nepal. Morphological, cultural, biochemical, biological and toxin-producing characteristics observed were used to type the isolates. In anaerobic meat medium, all isolates produced pinkish discoloration of meat. All the strains fermented lactose, maltose, dextrose and sucrose whereas, salicine was fermented only by 17 strains. All but five strains were MR negative. Out of 200 isolated, 166 produced both alpha and epsilon toxins and the remaining 34 non-toxogenic strains are likely to be variants which have lost their toxogenicity. Epidemiologically the local name "Six months disease" and enterotoxaemia are considered to be identical diseases.
The uak has two hemoglobins sharing a common globin chain. Hb slow appears unique to the yak among the ruminants studied. It is not known if Hb slow is important in high altitude adaptation, but physilogic rather than hematolgoic adjustments may be more important agter acute blood loss, as 2,3-DPG remains nit and no disproportionate hemolgoin production occurs.
Episodes of hemolysis and leukocytosis which were associated with Babesia bigemina followed each of 3 challenge exposures to influenza A viruses. It is possible that viral infection altered the immunologic host-parasite equilibrium. Acute thrombocytopenia and rouleaux formation were also observed. Death, attributed to liver flukes, occurred 168 days after the yak was transferred from high to low altitude. A 2nd yak died of foot-and-mouth disease, thus supporting the Nepali belief that yaks will not survive at the lower altitudes of Kathmandu.
Seroconversion for A/England/42/72 (H3N2) virus occurred in a child in Calcutta in August 1971, one month after the virus was first isolated in India. During the following 5 months a small increase was observed in the geometric mean titres (GMT). In mid-1972 the virus was in Kathmandu, Nepal, where the children had a higher GMT than the adults. The GMT increased sharply during 1972 and early 1973 and this increase was accompanied by an increased number of hospital admissions for respiratory diseases. Among the people in the isolated village of Lang Tang (3 500 m elevation), the GMT and prevalence for both A/England/42/72 and A/Hong Kong/1/68 (H3N2) were less than 50% of the Kathmandu values.
Naturally acquired antibody to H3N2 human influenza antigens was found in a yak-zebu crossbred in Nepal. Serial inoculation of a yak, negative for antibody, produced a response to A/Hong Kong/1/68 (H3N2), A/England/42/72 (H3N2), and A/Prague/1/56 (Heq1 Neq1) influenzavirus strains. Single radial diffusion tests showed that cattle and goats in West Bengal, India, and water buffaloes and cattle in Kathmandu, Nepal, also had antibodies against the H3N2 antigens. Haemagglutination-inhibition antibodies to equine influenzaviruses were not found in human, goat, cattle, chicken, and dog sera, nor were antibodies to avian viruses found in human or equine serum.