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Biomedical subjects

R L Sharma

Publications and source records attributed to R L Sharma.

29 records · Page 2Linked to original sources
PubMed1988

Control of sheep lungworm in India.

Lungworm infections (parasitic bronchitis) of sheep and goats are widely prevalent in hilly regions of India and neighbouring countries. Several species of strongyloid nematodes are involved but the most prevalent, and most pathogenic, is Dictyocaulus filaria - responsible for heavy mortality in young animals and severe morbidity in survivors. Control of these parasites now relies on a gamma-attenuated D. filaria vaccine developed in India in 1971. Vaccination of 6-week-old lambs has since become an accepted part of the regular sheep husbandry practice in India, and trials are now underway to extend use of the vaccine to goats, and to set up similar vaccination procedures in other countries. In this review, the authors trace the development of the D. filaria vaccine, highlighting its production and application. Although imperfect, the vaccine is now making a substantial contribution to improved sheep rearing by pastoral in the northern hill areas of India.

Journal Article↗
PubMed1987

Serum lactate dehydrogenase: clinical significance of alterations in its activity in lambs infected with Dictyocaulus filaria.

Alterations in the serum lactate dehydrogenase activity of Dictyocaulus filaria infected lambs were studied. The significant increase in its activity during patency correlated well with the progress of the disease and lung damage caused by the parasite. The enzyme may be of use in assessing the potency of D filaria vaccine and the chemotherapeutic value of an anthelmintic. Its use as a non-invasive method for earlier diagnosis and prognosis of the disease under experimental conditions is suggested.

Animals↗
PubMed1983

Oesophagostomum columbianum: gamma-irradiated third-stage larvae for immunization in lambs.

40-kR gamma-irradiated third-stage larvae of Oesophagostomum columbianum were used for the immunization of Kashmir Merino lambs. Male lambs (aged from 8 to 12 weeks) were immunized in two separate experiments by two doses of irradiated larvae, given 21 days apart, and subsequently challenged with normal larvae. Judging by the establishment of worms resulting from the challenge infections in the immunized and control groups of lambs in the two experiments, a high degree of immunity was shown to develop in young lambs vaccinated with 500, followed 21 days later with 2000, 40-kR irradiated larvae. Lambs from the immunized groups showed more nodules in the intestine, a high percentage of which were positive for histotrophic stages of O. columbianum, than did controls. The importance of this finding in relation to the possible use of a vaccine for the immuno-prophylaxis of oesophagostomiasis in sheep and other animals is discussed.

Animals↗
PubMed1982

Gastro-intestinal nematodes in sheep in Kashmir.

Examination at necropsy of the abomasum and intestinal tract of 62 sheep (including both sexes) of Karnah breed, aged one to two years over a period of one year was conducted at Handwara, situated in the north-west of Kashmir Valley. The following species of nematodes were found: Haemonchus contortus, Trichostrongylus axei, Trichostrongylus colubriformis, Bunostomum trigonocephalum, Chabertia ovina, Nematodirus spathiger, Skrjabinema ovis and Trichuris ovis. Infections with Trichostrongylus axei and T. colubriformis were, respectively, 57.7 and 40.2% of the total of all nematodes recovered. Faecal examination of adult sheep of Karnah breed, aged two to four years, comprising mostly pregnant and lactating ewes, showed a rise in strongyle egg counts during the months of March and April, coinciding with the lambing season in the area. The lambs showed a rise in faecal strongyle egg output from May onwards. The counts reached their peak during the month of September. It is presumed that pastures contaminated by pregnant and lactating ewes during the spring season were responsible for the acquisition of heavy nematode infections by lambs in the area.

Animals↗
PubMed1981

Immunization with irradiated larvae against Dictyocaulus filaria in young lambs.

In the lungworm-endemic areas of Kashmir, 6-10 week old lambs of Karnah and Kashmir Merino breeds were vaccinated with two doses of 50 kR gamma-irradiated larvae of Dictyocaulus filaria, given a month apart. Assessed on the basis of reduced prevalence and significantly lower faecal larval output over an eight-month observation period, vaccinated lambs showed a high degree of resistance to naturally acquired D. filaria infection. The results also show that vaccination against D. filaria provided some degree of protection against infection with other lungworm species.

Animals↗
PubMed1979

Immunization of lambs against Oesophagostomum columbianum, using irradiated third stage larvae.

The effect of gamma irradiation at doses of 40- and 50 kR on the development of third stage larvae of Oesophagostomum columbianum and the protection conferred by these irradiated larvae against the nematode, was studied in 6-8 week old male Kashmir Merino lambs. At 40- and 50 kR doses, the third stage larvae failed to develop to the adult stage in the intestine. Though single vaccination with 2000, 50 kR irradiated larvae failed to protect the animals against the infection, vaccination with the same number of 40 kR irradiated larvae conferred a partial protection. The presence of adult worms of O. columbianum in sites outside the intestine of 6-8 week old lambs have been demonstrated for the first time.

Animals↗
PubMedDate not supplied

Studies on the prevalence and laboratory transmission of fascioliasis in animals in the Kashmir Valley.

In Kashmir, 85.1% of cattle, 51.3% of sheep and 14.8% of goats were found infected with Fasciola spp. The prevalence rate varied from 66.6 to 100.0%, 25.0 to 100% and nil to 66.0% in cattle, sheep and goats respectively in different months of the year. Fasciola gigantica was the predominant species in all animal species but sheep harboured both F. gigantica and F. hepatica. The prevalence of F. hepatica infection in sheep happens to be the first report from India. Lymnaea auricularia sensu stricto supported the development of F. gigantica under laboratory conditions. The incubation temperature affected the shedding of the cercariae. Snails maintained at 25-27 degrees C started cercarial shedding as early as day 20 post-infection (PI), whereas those maintained at 10-12 degrees C commenced it from day 64 PI. One out of three experimentally infected guinea pigs aged 1 month revealed adult flukes in the liver at necropsy on day 52 PI.

Animals↗