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Biomedical subjects

K Banerjee

Publications and source records attributed to K Banerjee.

At least 145 records · Page 8Linked to original sources
PubMed1991

Entomological investigations during outbreaks of dengue fever in certain villages in Maharashtra state.

Outbreaks of dengue (DEN) fever are reported from 22 villages in five districts in the state of Maharashtra. DEN viral antigen was detected by indirect immunofluorescence test in 34 of 375 female Aedes aegypti mosquitoes collected from 8 villages. DEN types 2 and 3 were identified among the 16 strains that were isolated. None of the 64 male mosquitoes showed the presence of viral antigen; 281 males and 323 females reared from field collected larvae were also found negative. Indoor spraying of DDT in the affected villages produced a drastic reduction in Ae. aegypti catches. No viral antigen was detected in mosquitoes caught subsequent to the spray. With the introduction of water supply through taps, which is often inadequate, people are compelled to store water for domestic purposes, which favours an increase in Ae. aegypti breeding. In view of changing rural ecology associated with the development process, continued surveillance of the spread of Ae. aegypti as well as the diseases borne by this vector are recommended.

Aedes↗
PubMed1991

Outbreak of dengue fever in rural areas of Parbhani district of Maharashtra (India).

Outbreak of dengue fever in Chikalthana, Pimpalgaon and Waloor villages in Parbhani district of Maharashtra (India) were investigated. Clinically, the illness was typical of dengue fever except for the absence of maculopapular rash. A total of 42 acute, 14 late acute, 73 convalescent and 19 sera from contacts were collected. Of the 15 virus isolates, 12 were identified as dengue virus type 2 and 1 as dengue virus type 1. Serological tests confirmed the etiological role of dengue virus in the outbreak. House-to-house survey was carried out in Chikalthana and Pimpalgaon villages. Overall, 15.09 per cent of the surveyed population was affected during the outbreak and attack rate was higher at Pimpalgaon. A tendency of water storage was observed in the households and concomitant entomological studies proved Aedes aegypti breeding. Higher prevalence of dengue fever was noted among larger families and in families that had two or more patients, the commonest duration between the first and the last patient was often less than 5 days.

Antibodies, Viral↗
PubMed1990

Selection of a neutralization-escape variant strain of Japanese encephalitis virus using monoclonal antibody.

An Indian strain of Japanese encephalitis virus (JEV), 733913, a human isolate from Bankura, West Bengal in 1973, with all the functional epitopes designated by a panel of murine monoclonal antibodies (MAbs), was treated with one of the JEV specific HI reactive MAb(Hs-I). This led to selection of a neutralization-escape variant which showed loss of reaction to three different MAbs belonging to the same domain (Hs) and assumed similar characteristics to another JEV strain (755468) also isolated from Bankura in 1975 from mosquitoes. It is possible that selection of such variant might occur in presence of pre-existing JE antibody (Hs-I type) in pigs which are amplifying hosts of JEV. Subsequent dissemination of such variant virus could occur through mosquitoes.

Animals↗
PubMed1990

Characterization of a polyethylene glycol conjugate of recombinant human interferon-gamma.

Recombinant human interferon-gamma was conjugated with polyethylene glycol (PEG) using succinimidyl coupling of amino groups in the protein. The PEG conjugated material showed antiviral, growth inhibitory and macrophage activation activities indistinguishable from those of the unmodified protein. The PEG conjugation reduced the receptor binding affinity slightly, but increased the half-life of the protein when measured in rats. Almost no clearance was observed within 6 hr after injection for the PEG conjugated protein, whereas a rapid clearance was seen for the unmodified interferon-gamma. Two possible sites of PEG attachment were identified in the protein: the N-terminal amino group and either lysine 129 or 131.

Amino Acid Sequence↗
PubMed1990

Protective effect of 6-MFA, a fungal interferon inducer against Japanese encephalitis virus in bonnet macaques.

6-MFA, an extract from the fungus Aspergillus ochraceus was administered to 8 bonnet macaques. An equal number of monkeys matched for age, sex and weight received placebo and served as controls. Twenty hours after the administration of the 6-MFA/placebo the monkeys were challenged with an Indian strain of Japanese encephalitis virus by the intranasal route. Signs and symptoms of the disease such as fever, tremors, loss of appetite, dehydration, flaccid paraplegia or quadriplegia were pronounced in all the control monkeys, while in the 6-MFA treated group only two developed symptoms. Virus could be isolated from only one of the 6-MFA treated monkeys on day 6, and from four control monkeys; one each from CSF, spinal cord, blood and from both nasal swab and blood of the fourth monkey. The appearance of HI and N antibodies in 6-MFA treated group was either delayed or completely suppressed. The results indicate that 6-MFA is a potential antiviral agent which can be used to reduce the morbidity and mortality in bonnet macaques (Macaca radiata) experimentally infected with Japanese encephalitis virus.

Animals↗
PubMed1990

Plasma lactic dehydrogenase in mice infected with Japanese encephalitis & West Nile viruses.

A study of the total and isoenzymes fractions of lactic dehydrogenase (LDH) enzyme was carried out in the plasma of mice infected with Japanese encephalitis (JE) and West Nile (WN) viruses. Only 2 isoenzymes (LDH 4 and LDH 5) were present in control mice. There was a rapid increase of total LDH in the animals infected with the wild strain of viruses. Mice infected with wild strains of JE showed all 5 isoenzymes. LDH 1 disappeared after 12 days of infection but LDH 2 and LDH 3 persisted for 3 wk. The attenuated strain of JE did not produce any change either of the total content of the enzyme or of the isoenzyme pattern. In the plasma of mice infected with wild strains of WN viruses only 4 isoenzyme bands (LDH 2, 3, 4, 5) were detected. The LDH 3 persisted longer than LDH 2. With one strain of WN virus an extra band near LDH 4 was seen.

Animals↗
PubMed1990

Cloning & expression of chikungunya virus genes coding structural proteins in Escherichia coli.

DNA complementary to the single stranded RNA genome of Chikungunya (CHIK) virus with poly A tract was cloned into the plasmid pGEM-3Zf(-) and 5Zf(+) by blunt end ligation strategy. Clones containing the cDNA inserts were selected by X-gal, IPTG system. They were tested for the expression of structural protein(s) of CHIK virus by in situ enzyme immunoassay and Western blot. The former assay system showed the presence of expressed viral proteins. Analysis of Western blot shows that three structural proteins, E1, E2 and capsid (C) are expressed in Esch. coli. The molecular weights of envelope proteins E1 and E2 were 44-46 Kd and 42-44 Kd respectively, which are lesser than the actual molecular weights of virional proteins (50-52 Kd). This may be due to the absence of glycosylation of these proteins in Esch. coli. In clone no. 382, a high molecular weight protein (56-58 Kd) was observed, which was probably the unglycosylated form of P62 polyprotein coded by the virus during its multiplication. A small protein of MW 6-8 Kd was also expressed in clone nos. 382 and 504, and this appeared to be the unglycosylated form of E3 protein of CHIK virus.

Chikungunya virus↗
PubMed1990

Oligonucleotide fingerprint analysis of a wild strain & its attenuated variant of Japanese encephalitis virus.

A strain of Japanese encephalitis (JE) virus was passaged serially through primary chick kidney cell cultures (45 times) and primary baby hamster kidney cell cultures (21 times). The resultant virus lost its lethal effect to 3 wk old mice by the ic route and 10 day old mice by the ip route. The oligonucleotide fingerprint analysis of the parent and the passaged strains showed 64 spots in common; 17 spots were present in the parent strain which were absent in the passaged virus, while the latter had acquired 9 spots which were not present in the parent virus.

Animals↗
PubMed1989

The role of three domains in the biological activity of human interferon-alpha.

Earlier studies showed that minor differences in primary structure among the interferon-alpha (IFN-alpha) protein family are reflected in their potency in selected biological assays. These studies have been extended and results from assays of antiviral, growth inhibitory and 2',5'-oligoadenylate (2-5A) synthetase activities indicate that the various novel hybrid and analog species are differentially biologically active. Overall these observations suggest a correlation between predicted secondary structure characteristics, receptor binding affinity, and 2-5A synthetase, antiviral and growth inhibitory activities. Studies with a consensus IFN-alpha analog particularly implicated the region around residues 78 and 79 as influencing antiviral activity. Neutralization experiments with a monoclonal antibody directed against a conserved region from residues 113 to 149 indicated that although this region of the IFN-alpha molecule may be important for antiviral activity, altering residues at sites removed from this region may reduce the effectiveness of the neutralizing antibody. Receptor binding experiments suggested that no single site at either the amino or carboxyl terminus of IFN-alpha alone determines receptor affinity or biological activity: apparently three distinct domains along IFN-alpha are involved (10-35, 78-107, 123-166). Overall, the data indicate that the three sites contribute toward the active configuration of human IFN-alpha.

2',5'-Oligoadenylate Synthetase↗
PubMed1989

Identification of some antigenically related outer-membrane proteins of strains of Vibrio cholerae O1 and non-O1 serovars involved in intestinal adhesion and the protective role of antibodies to them.

Outer-membrane proteins (OMPs) of Vibrio cholerae strains of O1 and non-O1 serovars were studied. Marked similarity was found in the OMP profiles of different V. cholerae O1 strains but the OMP profile of a non-O1 strain was somewhat different. Antigenic relatedness between the OMPs of different V. cholerae strains was established by enzyme-linked immunosorbent assay (ELISA). Immunoblotting experiments demonstrated that at least two OMPs of 36 and 25-26 Kda were immunogenic and common to strains of O1 and non-O1 serovars. Antiserum raised against the outer membrane of a V. cholerae strain, and rendered specific for its OMP by absorption with lipopolysaccharide, inhibited in vitro the intestinal adhesion of the homologous and heterologous strains of V. cholerae irrespective of their biotype, serotype and serovar. Furthermore, antiserum to OMPs induced passive protection against vibrio challenge in rabbit ileal loop experiments. These results suggest that the OMPs may be useful in immunoprophylaxis against cholera.

Animals↗
PubMed1989

Oligonucleotide fingerprint analysis of Japanese encephalitis virus strains of different geographical origin.

RNA fingerprint analysis was carried out with different strains of Japanese encephalitis virus which were isolated from Japan, China, India and Sri Lanka. From the similarity ratios, a similarity matrix was worked out which yielded a dendrogram. Geographical proximity of the place of isolation did not contribute much to the similarity of the fingerprint of the strains, nor did temporal proximity. The Japanese Nakayama strain had greater similarity with the Asansol strain from West Bengal. However, another strain from West Bengal, the Bankura strain, showed marked difference. Similarly the Bhopal and Beijing (China) strains were relatively close to each other while the Japanese JaGAr15460 strain was nearer to the strain from Gorakhpur. Serial mouse passage of the Asansol strain did not change the fingerprint pattern drastically.

China↗