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A C Mishra

Publications and source records attributed to A C Mishra.

At least 37 records · Page 2Linked to original sources
PubMed2002

Establishment of two new cell lines from Bombyx mori (L.) (Lepidoptera: Bombycidae) & their susceptibility to baculoviruses.

BACKGROUND & OBJECTIVES: Lepidopteran cell cultures and baculovirus expression vector systems are becoming popular due to their potential applications in biotechnology especially for the expression of foreign proteins. Efforts were made to develop new, indigenous, cell lines from Bombyx mori larvae and pupae. METHODS: Eight to ten B. mori larvae and 10-12 pupae were surface sterilized, dissected and ovaries were removed aseptically. Ovaries were chopped finely, washed and suspended in growth medium. When the cells formed monolayers, they were subcultured and experiments were carried out. RESULTS: Two new cell lines from larval and pupal ovaries of B. mori were established in Grace's insect tissue culture medium supplemented with 20 per cent FBS (foetal bovine serum). The larval cell line consisted predominantly of epithelial-like cells (98.31%), whereas the pupal cell line had a mixed cell population of epithelial-like (71.8%) and fibroblast-like cells (27.8%). Karyology indicated a typical lepidopteran pattern in both the cell lines and had chromosome numbers ranging from 35 to 150 and 60 to 180 for larval and pupal ovaries respectively. Four-fold increase in cell number was observed in these cell lines in 7 days. Both the cell lines were found susceptible to B. mori multiple nucleopolyhedrovirus and Autographa californica multiple nucleopolyhedrovirus, but not to Helicoverpa armigera single nucleopolyhedrovirus and Spodoptera litura multiple nucleopolyhedrovirus. INTERPRETATION & CONCLUSION: These well characterized cell lines may be of immense application in biotechnology and medicine for the production of biologically active recombinant proteins to use in vaccine studies as well as in therapeutic applications.

Animals↗
PubMed2002

A new cell line from the embryonic tissues of Culex tritaeniorhynchus and its susceptibility to certain flaviviruses.

A new cell line from the embryonic tissue of Culex tritaeniorhynchus mosquito was established. Morphological studies carried out at the 45th passage level (P-45) showed four different cell types viz. epithelial-like cells, fibroblast-like cells, giant cells and vacuolated cells. Karyological studies indicated diploid (2n = 6) chromosomes in majority of cells irrespective of passage level. A twelve-fold increase of cell number was observed in 10 days at P-49. The cells could be preserved in liquid nitrogen for more than 40 months. Isoenzyme profile analysis with four enzymes clearly indicated that this cell line was derived from C. tritaeniorhynchus. This cell line was susceptible to Japanese encephalitis (JEV) and West Nile viruses (WNV) but not to Dengue 1-4 (DEN 1-4) viruses. Protein of 38 K was detected in the membrane fraction of the cells from this and the C6/36 cell line, which was found to bind DEN 1-4 viruses. These data suggest that DEN viruses bind to this membrane protein and probably enter into the cells but do not continue further in the replication process.

Animals↗
PubMed2002

Study of the effect of the midgut bacterial flora of Culex quinquefasciatus on the susceptibility of mosquitoes to Japanese encephalitis virus.

Culex quinquefasciatus mosquitoes were collected from the field and microbial flora was isolated from their midgut. Isolates belonging to 13 different genera were obtained. Four most abundant isolates viz. Pseudomonas sp., Acinetobacterjunii, Staphylococcus epidermis and Aeromonas culicicola were used to study their effect on the susceptibility of mosquitoes to Japanese encephalitis virus (JEV). Incorporation of individual isolates in the mosquito bloodmeal resulted in an increased susceptibility of mosquitoes to the virus. However, only the effects of Pseudomonas sp. and Acinetobacterjunii could be statistically evaluated but they were found insignificant.

Animals↗
PubMed2001

Prevalence of anti-hepatitis E virus antibodies in different Indian animal species.

Prevalence of IgG antibodies to hepatitis E virus (IgG-anti-HEV) was determined among different animal species from India. Seropositivity varied from 4.4% to 6.9% in cattle, 54.6-74.4% in pigs and 2.1-21.5% in rodents. Of the 44 dogs screened, 10 were positive (22.7%). None of the 250 goat sera tested were found to be anti-HEV positive. Among rodents, over 50% serum samples collected in 1985 from Bandicota bengalensis were positive for anti-HEV antibodies. No evidence of HEV infection was obtained following experimental inoculation of an Indian strain (AKL-90) of HEV into anti-HEV negative pigs and goats. The results document varied prevalence of anti-HEV antibodies in different animal species from India and of inability of Indian pigs and goats to support replication of at least one human strain of HEV.

Animals↗
PubMed2001

Transovarial transmission of West Nile virus in Culex vishnui mosquito.

The phenomenon of transovarial transmission (TOT) of West Nile (WN) virus in Culex vishnui was studied. The virus was detected in the progeny of both first and second gonotropic cycles (G1 and G2). About 5.56 per cent pools of F1 progeny from the parent females infected by the oral route were found positive for WN virus. This is the first report of TOT of WN virus in this species of mosquito. The occurrence of this phenomenon is of considerable importance in view of complex natural cycle of the virus and the high density of this vector species in nature. The results suggest that this mosquito may be involved in the maintenance of this virus in nature.

Animals↗
PubMed2001

Antigen distribution pattern of West Nile virus in Culex tritaeniorhynchus, Culex vishnui and Culex pseudovishnui mosquitoes.

Distribution of West Nile (WN) virus antigen in different tissues of mosquitoes was studied in three species viz., Culex tritaeniorhynchus, C. vishnui and C. pseudovishnui. Overall per cent positivity was higher in the intra thoracically inoculated as compared to the orally infected mosquitoes, suggesting the existence of a midgut barrier. In a small number of mosquitoes salivary glands were found negative even though fluorescence was seen in the respective head squashes, suggesting salivary gland barrier in these mosquitoes. There was no difference in the per cent salivary gland and salivary gland area positivity between these three species. Presence of virus antigen in the ovaries of these three species on the 3rd post infection day suggests the possibility of transovarial transmission of virus even in the first gonotrophic cycle, which is of epidemiological importance.

Animals↗
PubMed2000

Antigen distribution pattern of Japanese encephalitis virus in Culex tritaeniorhynchus, C. vishnui & C. pseudovishnui.

Distribution of Japanese encephalitis (JE) virus antigen in different tissues of mosquitoes was studied in three species viz., Culex tritaeniorhynchus, C. Vishnui and C. pseudovishnui. Overall per cent positivity was higher in the intrathoracically infected as compared to the orally infected mosquitoes, suggesting the existence of a midgut barrier. The cells at the junction of the foregut-midgut, and midgut-hindgut showed intense fluorescence from the second day post feeding onwards. This suggests that the dissemination of virus takes place from these regions of the gut. A small number of salivary glands were found negative even though fluorescence was seen in the respective head squashes, suggesting involvement of the salivary gland barrier in these mosquitoes. Though there was no difference in the salivary gland positivity between these three species, the salivary gland area positivity was high in C. tritaeniorhynchus mosquitoes. Presence of virus antigen in the ovaries and developing eggs of these three species on the third day suggests the possibility of transovarial transmission of virus even in the first gonotrophic cycle which may have epidemiological importance.

Animals↗
PubMed1994

Studies on the mosquito vectors of Japanese encephalitis virus in Mandya District, Karnataka, India.

Entomological investigations were carried out in areas affected by Japanese encephalitis (JE) in Mandya District, Karnataka, India, from 1983 to 1988, to determine species composition and the density of mosquito vectors, in relation to the incidence of JE cases. JE cases occurred in two spells in a year, one during April-June (summer epidemic) and another during October-December (winter epidemic). There was very high incidence of JE cases in extensively irrigated areas and a low incidence in some of the taluks with less or no irrigation systems. Among culicines, Culex tritaeniorhynchus was the most predominant species (20.54%), followed by Cx. fuscocephala (16.94), Cx. vishnui (16.48%), Cx. gelidus (10.70%) and other species. The overall mosquito population showed two peaks in a year, one during the March-April, and another during September, usually preceding the human epidemics. Relative abundance of certain species varied in different years.

Animals↗
PubMed1994

Biochemical basis of DDT-resistance in Aedes aegypti population from a dengue affected area in Shahjahanpur city.

Entomological studies conducted in Jalalnagar, Shahjahanpur city, Uttar Pradesh, India, during an outbreak of dengue in 1992, showed that Ae. aegypti mosquitoes were resistant to DDT and had some tolerance to malathion in the adults and the larvae. Biochemical analysis suggested that DDT resistance was related to elevated glutathione s-transferase and tolerance to malathion was due to a little increase in esterase activity. Crosses of DDT-resistant and susceptible strain suggested that resistance was codominant (metabolic type).

Aedes↗
PubMed1991

Transmission of Japanese encephalitis virus in Culex pseudovishnui & C. tritaeniorhynchus mosquitoes.

Studies on the transovarial transmission of Japanese encephalitis virus (JEV) by orally infected female C. pseudovishnui showed that these mosquitoes were capable of transmitting JEV by bite to susceptible hosts. Infected females also transmitted the virus vertically to its first generation progeny. In another experiment, C. tritaeniorhynchus was also shown capable of transmitting the virus vertically to its first generation progeny. However, there was no apparent difference in transovarial transmission capabilities of these two species in orally infected mosquitoes.

Animals↗
PubMed1990

Immunopathological changes in kidney in Plasmodium falciparum malaria.

Fifteen (34.8%) of 43 patients of falciparum malaria screened for urinary abnormalities showed significant proteinuria (greater than 150 mg/24 h), haematuria (greater than 1/HPF) and casts, with or without azotaemia. Light microscopic examination of renal biopsy tissue from 12 patients revealed mesangial and endothelial proliferative change in 8, and acute tubular necrosis in one patient. Immunofluorescence showed IgM alone, or IgG and IgM along with C3, in 7 patients within the mesangium or along the capillary walls. Repeat kidney biopsy after 6 wk in 5 patients revealed no residual pathology indicating the reversible nature of the lesions.

Animals↗
PubMed1990

Double blind clinical trial on centperazine & DEC in bancroftian filariasis.

Centperazine, an analogue of DEC, was subjected to a double blind controlled trial, to evaluate its efficacy as a newer antifilarial agent. Centperazine (300 mg/day) along with equivalent quantities of DEC and placebo were administered to different types of filariasis patients. DEC was found to be significantly effective in reducing peripheral microfilaraemia, in different weeks and months of follow-up, except at the end of 6th month, as compared to Centperazine. There was no significant difference between the placebo and Centperazine treated patients, in this respect, revealing that the drugs had no efficacy in eliminating peripheral microfilaraemia. Recurrence of acute attack within 6 months was nearly equal with both Centperazine and DEC, being 28.2 and 24 per cent respectively, whereas in the placebo group the recurrence rate was 48.9 per cent. Centperazine treated patients showed significantly less side effects (8.9%), as compared to DEC treated patients (34%). Giddiness, nausea and vomiting were the common adverse effects observed.

Adolescent↗
PubMed1989

Japanese encephalitis virus infection in mosquitoes reared from field-collected immatures and in wild-caught males.

Immature stages of mosquitoes collected in JE endemic areas of Karnataka, India between 1985 and 1987 were reared to adults and processed for the detection and isolation of Japanese encephalitis (JE) virus in an attempt to find naturally occurring vertical transmission of the virus. Males collected during 1985-1986 were also processed. A total of 15,785 adults reared from immatures and divided into 445 pools and 1,756 wild-collected males divided into 128 pools were processed using mosquito inoculation and immunofluorescence techniques. JE virus antigen was detected in 9 pools, 4 of which yielded JE virus. These were 2 pools of males and 1 pool of female Culex tritaeniorhynchus and 1 pool of male C. pseudovishnui, suggesting vertical transmission of JE virus in the mosquitoes.

Animals↗
PubMed1988

Absence of viraemia in cattle after experimental infection with Japanese encephalitis virus.

Cow calves were infected with Japanese encephalitis virus (JEV) by parenteral inoculation. One batch was reinfected with JEV, followed by West Nile virus (WNV), while another batch was reinfected directly with WNV. No viraemia due to either JEV or WNV was demonstrated in any of the calves. Culex tritaeniorhynchus mosquitoes fed on 4 of the calves infected with JEV during the first 10 d had no detectable virus, nor did they transmit the virus by bite to susceptible baby chickens. In another experiment, calves did not develop viraemia after infected C. tritaeniorhynchus mosquitoes were allowed to feed on them. Neutralizing and/or haemagglutination-inhibiting antibodies against JEV were demonstrated in 6 of the 11 calves, which explains the high proportion of JE seropositives among cattle in India. All the 5 calves that were infected with WNV subsequent to JEV developed neutralizing and haemagglutination-inhibiting antibodies against WNV also. The study indicates that cattle do not play a role in the maintenance of JEV in nature.

Animals↗
PubMed1987

Beta spectroscopy with liquid scintillation systems: applications in dosimetry of 90Sr and 90Y.

We have demonstrated that commercially available liquid scintillation counters are adequate for obtaining useful information about the variation of beta spectral shapes as a function of attenuation. A gel scintillation system that permitted the approximation of point source geometry worked well. The spectral shapes predicted by the Fermi equations were reasonably matched with experimental spectra of sources with geometry close to a point source. For energies in the range of 50-2300 keV, we found sufficient linearity of the energy scale and uniformity of detection limits for the direct output of the instrument to be experimentally useful. The gel scintillation system has been used to directly measure the energy distribution of the beta flux coming out of bone samples and incident on the soft tissue of dogs fed 90Sr-90Y from in utero to 540 days of age.

Animals↗