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Biomedical subjects

R D Sharma

Publications and source records attributed to R D Sharma.

At least 19 recordsLinked to original sources
PubMed1998

Successful long-term in vitro cultivation of Theileria annulata schizonts in media supplemented with homologous and heterologous sera.

The efficacy of medium RPMI-1640 supplemented with either foetal bovine, normal bovine, goat or sheep sera was compared for prolonged in vitro propagation of Theileria annulata (Hisar) schizonts. Medium RPMI-1640 supplemented with 20% foetal bovine serum (standard growth medium) resulted in optimum growth of T. annulata (Hisar) schizonts in vitro. Comparable viability and non-viability counts were observed in growth media supplemented with normal bovine or goat sera. However, viability counts in medium supplemented with sheep serum were significantly lower than that of the standard medium. Mitotic indices of cultures of T. annulata (Hisar) schizonts were directly related to the extent of cell growth and were lower in various growth media supplemented with normal bovine, goat or sheep sera than in that of the standard medium. The results suggested that normal bovine and goat sera could be successfully used in place of foetal bovine serum in the growth medium for long-term in vitro propagation of T. annulata schizonts. The study will help in reducing the cost of large-scale in vitro propagation of T. annulata aimed at mass production of the cell culture vaccine.

Animals↗
PubMed1998

Monoclonal antibodies against conformationally dependent epitopes on porcine reproductive and respiratory syndrome virus.

Monoclonal antibodies (MAbs) against porcine reproductive and respiratory syndrome virus (PRRSV) were prepared and characterized. Four MAbs were developed from the mice immunized with the recombinant GP4 protein expressed in insect cells, and six MAbs were derived from the immunization with recombinant GP5 protein. All of the MAbs showed strong perinuclear fluorescence in PRRSV VR2385 infected cells by immunofluorescence staining. Among the MAbs to GP5 protein, one showed strong reactivity in ELISA and recognized a 26 kDa band of PRRSV in a western blot assay, while another showed neutralizing activity against the VR2385 isolate. Out of the four MAbs to GP4 protein, one showed mild reactivity in ELISA with detergent extracted antigen, but had no reactivity in a western-blot assay. The failure of MAb binding to detergent extracted antigen in ELISA or in western-blot analysis indicated that the MAbs were against conformationally dependent epitopes. Reactivity patterns of the MAbs with PRRSV field isolates tested by fixed-cell ELISA showed that there are antigenic variations in PRRSV GP4 and GP5 proteins. Development of these MAbs will benefit further studies on PRRSV structural proteins as well as in understanding their roles in PRRSV pathogenesis.

Animals↗
PubMed1998

Susceptibility to tropical theileriosis of calves born to dams immunized with Theileria annulata (Hisar) cell culture vaccine.

The susceptibility/immune status to tropical theileriosis of calves born of immunized dams was evaluated. Six cows were vaccinated with the Theileria annulata cell culture vaccine in the eighth month of pregnancy. Sera from the immunized dams exhibited very high post-vaccination antibody titres as determined by the indirect fluorescent antibody (IFA) test. The calves born to these dams did not show antibodies against T. annulata at the time of birth (IFA titres of < 1:20). The new-born calves were fed colostrum from their mothers and were challenged with T. annulata-infected ground tick supernate at 5-7 days of age. All the calves developed fever (from day 5-6 onwards) and parasitological reactions (from day 8-9 onwards) after challenge. There was a significant decrease in the haemoglobin and packed cell volume of the calves after challenge. All the calves showed signs of acute theileriosis by day 9-10 after challenge and had to be treated with buparvaquone in order to save their lives. The study indicated that detectable levels of anti-theilerial antibodies were not transferred from immune dams to their offspring. All the calves born to immunized dams were fully susceptible to theileriosis and thus themselves needed vaccination.

Animals↗
PubMed1997

Responses in animals vaccinated with the Theileria annulata (Hisar) cell culture vaccine.

Bovine tropical theileriosis caused by Theileria annulata is an economically important disease of cattle in India. The disease has assumed paramount importance with the intensification of cross-breeding programmes aimed at enhancing milk production in the country. To control this disease, a cell culture vaccine was developed in this department by continuous passaging of T. annulata (Hisar) schizonts in vitro. Current work in this department has concentrated on the epidemiology of theileriosis: development of the cell culture vaccine for very young calves and pregnant cows; evaluation of serological responses using immunofluorescent antibody (IFA) tests and Enzyme-linked immunosorbent antibody assays (ELISA); studies on the duration of immunity stimulated by the cell culture vaccine; the immune/susceptible status of calves born to vaccinated dams. Results have shown the following. Clinical cases of theileriosis were mainly observed in young calves below two months of age followed by adults in exotic and cross-bred animals. Amongst indigenous animals, only young calves below two months of age suffered from clinical disease. Clinical cases of theileriosis mainly occurred between the months of April to October. The T. annulata schizont cell culture vaccine developed in the department was extensively used in the susceptible calves and pregnant/lactating cows in the field. Sufficiently high antibody titres were detected by both schizont as well as piroplasm antigen using both ELISA and IFAT. The results indicated that the vaccine was safe, potent and effective for all breeds and age groups of cattle under field conditions. ELISA was standardised for T. annulata using three antigens, viz.: soluble piroplasm, soluble schizont and cellular schizont antigens. Comparison of results with IFAT showed that ELISA is more sensitive, objective, reliable and specific as well as less cumbersome than IFAT. Piroplasm, cellular schizont and soluble schizont antigens were found to be suitable for the detection of antitheilerial antibodies as per their order in ELISA. Studies on the duration of immunity stimulated by the T. annulata schizont cell culture vaccine indicated that immunity started waning after six months. Calves born of dams immunised against T. annulata with the cell culture vaccine were found to be fully susceptible to theileriosis soon after birth. This indicated that there was no passive transfer of immunity from dams to their offspring through colostrum.

Animals↗
PubMed1997

An immunisation trial with in vitro produced Babesia bigemina exoantigens.

Bovine babesiosis, caused by Babesia bigemina, is an important tick-transmitted haemoprotozoan disease in the tropics. This study evaluated the immunoprotective efficacy of in vitro produced B. bigemina exoantigens in bovine calves. The calves inoculated with B. bigemina exoantigens did not show any clinical, parasitological or hypersensitivity reactions after inoculation. They withstood challenge without showing any clinical symptoms except a transient thermal reaction. In contrast, two out of four control calves exhibited clinical symptoms of babesiosis and one died. On challenge, there was a significant reduction in the haematological values of both groups. However, this was more pronounced in the control animals. Challenge resulted into a normocytic hypochromic anaemia. The vaccinated animals revealed a significant rise in antibody titres after vaccination as well as after challenge as detected by a single dilution ELISA. The rise in antibody titres of control animals was only moderate. Inoculation of B. bigemina exoantigens induced a protective immune response in the vaccinated animals which could protect them from infected blood challenge.

Animals↗
PubMed1997

In vitro propagation of Theileria annulata infected schizonts in different media supplemented with heterologous sera.

Efficacy of medium RPMI-1640 (supplied by Gibco USA, Centron and Hi-media) supplemented with horse, donkey, sheep and goat sera was evaluated for in vitro propagation of Theileria annulata (Hisar) infected bovine mononuclear cells. The results were compared with the growth rate in RPMI-1640 supplemented with foetal bovine serum (Gibco). RPMI-1640 (Gibco) proved to be the best medium for in vitro cultivation of the parasite infected cells. Foetal bovine serum could be easily, safely and reliably substituted with goat and sheep sera in the growth medium. Horse and donkey sera also gave comparable growth of T. annulata infected cells in vitro. Successful use of heterologous sera greatly helped in reducing the cost of in vitro cultivation of T. annulata schizonts. These findings have important implications on mass production of an attenuated cell culture vaccine for the control of bovine tropical theileriosis.

Animals↗
PubMed1996

Efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions.

The efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions were studied in 42 patients. The diagnostic yield of unguided aspiration was 83.3%. The yield in malignant lesion was 85.7% while in benign lesion it was 78.6%. There was no false positive report. Complications seen were asymptomatic pneumothorax and blood tinged sputum in a few cases following aspiration. The procedure was well accepted by the patients. Unguided FNAC is a simple, quick, economical, safe and reliable procedure for the diagnosis of peripheral lung lesions.

Adolescent↗
PubMed1990

Effect of fenugreek seeds on blood glucose and serum lipids in type I diabetes.

The effect of fenugreek seeds (Trigonella foenum graecum) on blood glucose and the serum lipid profile was evaluated in insulin-dependent (Type I) diabetic patients. Isocaloric diets with and without fenugreek were each given randomly for 10 d. Defatted fenugreek seed powder (100 g), divided into two equal doses, was incorporated into the diet and served during lunch and dinner. The fenugreek diet significantly reduced fasting blood sugar and improved the glucose tolerance test. There was a 54 per cent reduction in 24-h urinary glucose excretion. Serum total cholesterol, LDL and VLDL cholesterol and triglycerides were also significantly reduced. The HDL cholesterol fraction, however, remained unchanged. These results indicate the usefulness of fenugreek seeds in the management of diabetes.

Adolescent↗
PubMed1986

Rice bran oil and hypocholesterolemia in rats.

Rats fed rice bran oil at 10% level for a period of eight weeks showed significantly lower levels of total cholesterol, low density lipoprotein and very low density lipoprotein cholesterol, both on cholesterol-containing and cholesterol-free diets. High density lipoprotein cholesterol was increased but triglyceride showed a decrease that was not statistically significant. Liver cholesterol and liver triglycerides were also reduced. Fecal excretion of neutral sterols and bile acids was increased after ingestion of rice bran oil.

Animals↗