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Biomedical subjects

K Banerjee

Publications and source records attributed to K Banerjee.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cultivation of buffalo green monkey kidney cells persistently infected with hepatitis A virus.

Studies were carried out to determine the effect of prolongation of incubation periods, cocultivation with normal buffalo green monkey kidney (BGMK) cells and different concentrations of foetal calf serum (FCS) on the production of hepatitis A virus (HAV) by BGMK cell line persistently infected with HAV strain HM175. HAV could be detected from week 1 onwards. However, maintenance of cultures beyond this period was found to yield substantially higher quantities of virus. Cocultivation of persistently infected cells with normal BGMK cells also improved the antigen yields. Different concentrations of FCS did not show any effect on the amount of virus produced. The cell line was maintained up to 46 passages during which there was continuous production of HAV in the cells and release of small amounts of virus in the culture supernatants. Cell associated and cell free viral particles were found to be infectious. Supernatant derived virus was a highly suitable inoculum for infecting other susceptible cell lines. Persistently infected BGMK cell line appears to be a reliable and economical source to derive HAV in adequate amounts for diagnostic and research purposes.

Animals↗
PubMed1994

Indigenous anti-hepatitis A virus IgM capture ELISA for the diagnosis of hepatitis A.

Anti-hepatitis A virus IgM capture ELISA was developed by using the reagents produced in the NIV laboratory. The major reagents of the assay were anti-human IgM antibody, hepatitis A virus (HAV) and anti-HAV IgG-horse radish peroxidase (HRP) conjugate. Of these, anti-human IgM antibodies were generated in rabbit against IgM secreted by human hybridoma clone(G3). HAV was derived from buffalo green money kidney cell line infected with HM-175 strain. Virus purified from the cell lysates was used for immunization of rabbits and guinea-pigs. There was very low anti-HAV response. A seropositive rhesus monkey was inoculated with monkey adapted strain of HAV to boost the anti-HAV antibody titre. Anti-HAV IgGs derived from hyperimmune sera of monkey and hepatitis A patient were conjugated with HRP. The preparations of conjugate--particularly human antibody--HRP conjugate yielded highly satisfactory results in anti-HAV capture ELISA. The assay appears to be specific, sensitive and quick and is useful in differentiating acute HAV infection from other acute infections caused by B, E and non-A non-B hepatitis viruses.

Animals↗
PubMed1993

Analysis of computer-predicted antibody inducing epitope on Japanese encephalitis virus.

Theoretical methods to delineate antibody inducing epitopes have been employed to predict antigenic determinants on envelope glycoprotein (gpE) of Japanese encephalitis (JE), West Nile (WN) and Dengue (DEN) I-IV viruses. A predicted region on JE virus gpE 74CPTTGEAHNEKRAD87 was synthesized, conjugated to KLH (KLH-peptide) and used in immunization of mice. A mouse monoclonal antibody (MoAb IVB4) reactive to the peptide was also found to react with native JE virus gpE. Characterization of the idiotypic (ID) determinants with the help of polyclonal domain-specific anti-ID antibodies revealed that polyclonal anti-KLH-peptide antibodies and MoAb IVB4 are flavivirus-cross-reactive to Hx and NHx domains, respectively. The region 74-87 in JE virus gpE has been mapped as a linking area between Hx and NHx domains. Reactivity of the peptide with sera from JE patients and vaccinees also indicated the feasibility of using predicted peptides for diagnostic and prophylastic purposes.

Amino Acid Sequence↗
PubMed1993

Rhesus monkeys infected with hepatitis E virus (HEV) from the former USSR are immune to subsequent challenge with an Indian strain of HEV.

Two rhesus monkeys (M. mullata) of approximately two years of age were inoculated intravenously with a 10% suspension of hepatitis E virus (HEV) positive stool from Kirghistan as evidenced by immuno-electron microscopy. Evidence of HEV infection was demonstrated by rise in serum alanine transaminase (ALT) levels and seroconversion of these monkeys to anti-HEV after 1-1/2 months post-inoculation as evidenced by immunoblot. One year after the primary inoculation, these monkeys were challenged with an Indian strain of HEV. No rise in serum ALT levels was noted during an observation period of 6 months. The same inoculum produced HE in two rhesus monkeys. The results showed that strains from India and Kirghistan were antigenically closely related and rhesus monkeys infected with one strain of virus were immune to another strain.

Alanine Transaminase↗
PubMed1993

Epidemiological features of cholera outbreak in Delhi in 1988.

During 1988 a large scale outbreak of cholera occurred in Delhi giving rise to a total of 1708 bacteriologically proved El Tor cholera cases, the highest number recorded in a single year in Delhi, following its first detection in 1965. Civil lines and Shahdara zones were the worst affected areas recording 85.7 and 55.7 cases per 100,000 population respectively. The highest incidence rate was observed in the age group of 1-4 years (77 per 100,000). Males and females were equally affected. The data of moving average show the endemicity of cholera in Delhi with an increasing trend. The risk factors identified are lower socioeconomic status, poor personal hygiene, drinking water and food storage practices.

Adult↗
PubMed1993

An investigation of an outbreak of viral hepatitis in a residential area of Delhi.

Epidemiological investigation of a focal outbreak of jaundice in the KD block of Pitampura, Delhi during February-March 1992 revealed that 7.0 per cent of the population of the block suffered from viral hepatitis. There was no age or sex predilection. Epidemiological findings and Serological studies suggest that the epidemic was due to Hepatitis E (Enterically transmitted Non A and Non B) virus.

Adolescent↗
PubMed1993

Immunofluorescence studies on the replication of some arboviruses in nucleated and enucleated cells.

Porcine stable kidney (PS) or Vero cells infected with either flavi-(Japanese encephalitis--JE, West Nile--WN, and Dengue--DEN-2) or alphaviruses (Chikungunya--CHIK and Sindbis--SIN) were stained in indirect fluorescent antibody (FA) assay with anti-JE virus monoclonal (MoAb) Hx-3 (flavivirus cross-reactive) and polyclonal (immune PF) antibodies. By 48 hr post infection (p.i.), 15 to 20% of the three flaviviruses and CHIK virus infected cells, which revealed positive cytoplasmic immunofluorescence (IF), showed intranuclear IF. By 24 hr p.i., the intranuclear IF was not observed or became diminished. The enucleation of cells by cytochalasin B treatment prior to the infection with any of the three flaviviruses resulted in the loss of IF compared with the cells enucleated after the infection (18 hr p.i.) whereas SIN or CHIK virus-infected cells reacted similarly by the either method. These findings indicate an essential role of the nucleus in the replication of the flaviviruses only and while replicating in the infected cells, flaviviruses and CHIK virus might express viral specific proteins in the cell nuclei.

Alphavirus↗
PubMed1993

Practices of preparation of oral rehydration solution among mothers reporting to the drug distribution centres in Delhi, India, 1992.

A study to assess the ability for preparing oral rehydration solution (ORS) correctly among the recipients of ORS packets from the Government of India service outlets was carried out in Delhi during July to August, 1992. One centre from each of the municipal zones of Delhi was selected randomly. Four hundred mothers with a child having diarrhoea reporting to the nearest centre were studied using a standardized questionnaire adopted from the WHO household survey schedule. Two paramedical personnel from each of the centres who were responsible for distribution of ORS were also interviewed regarding their knowledge of preparation of ORS. Results indicate that only 10.8% of mothers prepared the ORS correctly and that the majority (83%) of the paramedicals involved in ORS distribution had correct knowledge about its preparation. Communication methods directed at the mothers regarding the preparation of ORS should be stepped up in these communities.

Child, Preschool↗
PubMed1992

Identification and characterization of mutations in 'X' region of a hepatitis B virus carrier.

A defective form of Hepatitis B virus (HBV) was identified in an apparently healthy voluntary blood donor, who was positive for the presence of HBV by dot blot hybridization, but did not have any serological markers of HBV infection. Two regions, part of X and part of surface antigen genes, were amplified by polymerase chain reaction, cloned and sequenced by Sanger's dideoxy chain termination method. The base sequence analysis revealed that the HBV mutant belonged to ayw serotype and showed three point mutations, in the form of deletions at nucleotides number 1402, 1438 and 1450. Such mutations in the 'X' region, and their likely presence elsewhere, could explain altered antigenic expression.

Amino Acid Sequence↗
PubMed1992

Comparative immunogenicity of different hepatitis B vaccines among certain high risk groups in India.

The immunogenicity of three different commercially available, well established Hepatitis B vaccines was determined. Three groups of high risk individuals were administered the vaccine, viz, Albugam (20 micrograms), Engerix-B (20 micrograms) and vaccine produced by Cheil Sugar & Co. (3 micrograms) respectively in a schedule of 3 doses as recommended by the manufacturers. A fourth group was administered a combination of the Albugam (2 doses) and Engerix-B (1 dose) vaccine. The sera collected 2 months after the 3rd dose showed seroconversion rates to be 100 percent and 95.34 percent respectively in the group which received the Albugam and Engerix-B vaccines respectively. The group which received a combination of both, the seropositivity rate was also 100 percent. The Chiel Sugar vaccine gave a seroresponse of only 52.38 percent. Geometric mean titres among the groups which received Albugam vaccine (501.30) were comparable to those receiving the combination of Engerix-B and Albugam (442.28). Those who received all 3 doses of Engerix-B vaccine showed a significantly lower GMT as compared to the above tow groups (GMT--43.14, p < .001, P < .001 respectively). The GMT in the group that received Cheil Sugar Vaccine was 3.81. Seroresponse was found to be inversely proportionate to age.

Adult↗
PubMed1992

Monoclonal antibody to Japanese encephalitis virus cross-reacting with histones present in the cell nuclei.

An immunoglobulin G (IgG2b) class of monoclonal antibody (MoAb, NHA-1) raised against Japanese encephalitis virus (JEV) E glycoprotein, reacted with the viral antigen expressed in cytoplasm of the infected cells and also with the cell nuclei, by an indirect fluorescent antibody technique (FA). The NHA-1 reactivity to nuclei was found to be due to its recognizing a JEV cross-reactive epitope present on the nuclear histones. Adsorption with calf thymus histones (type II-AS) showed a drop in NHA-1 reactivity to both JEV and histones by an enzyme-linked immunosorbent assay (ELISA) and indirect FA; the drop was higher against the histones. The MoAb recognized specifically the viral antigens expressed on the infected porcine kidney cell surface by a modified indirect FA. ELISA carried out with glutaraldehyde-fixed antigens showed an almost 2-fold increase in the reactivity over unfixed JEV antigen but none for the histones. Thus, the results indicate that histones share a sequential homology with E glycoprotein of JEV, which might lead to an autoimmune disorder induced due to the molecular mimicry between these two antigens.

Animals↗
PubMed1992

Serum beta 2 microglobulin levels in HIV seropositive persons.

As beta 2 microglobulin (B2M) has been found to be elevated in immunological disorders and also in HIV infection, its levels were studied in 475 HIV seropositive, asymptomatic persons; 101 HIV seronegative persons from high risk groups for HIV and 99 healthy controls. The B2M levels in asymptomatic HIV seropositives are found to be significantly higher than healthy controls (1.0 mg/1 to 2.7 mg/1, P less than 0.001) and HIV seronegatives from high risk groups (1.1 mg/1 to 2.7 mg/1, P less than 0.001). Two hundred and thirty four (49.26%) seropositives showed increased levels of serum B2M. Thus, quantitative analysis of B2M may be useful as an early nonspecific marker of HIV infection and immune dysfunction. The prognostic value of B2M was assessed in a follow up study of 54 HIV seropositives in a 2 yr period. Within this period, B2M levels were found to be significantly increased in these subjects (1.2 mg/1 to 4.6 mg/1, P less than 0.001). Three of the subjects who showed high increase in the B2M levels, progressed to AIDS-related condition, whereas one progressed to persistent generalised lymphadenopathy. Thus, the rising levels of B2M appears to correlate well with disease progression.

Follow-Up Studies↗
PubMed1992

Polymerase chain reaction based diagnostic assay for identification of hepatitis B virus.

A highly sensitive polymerase chain reaction (PCR)-based diagnostic assay was developed to detect the presence of hepatitis B virus (HBV) in human serum. The assay involved amplification of HBV DNA sequences using primers specific to HBV. This in vitro enzymatic amplification technique, when used in combination with molecular hybridization assay can detect HBV genome in the patient's serum, with a higher degree of sensitivity than achieved with dot blot assay. The assay can identify samples containing 3-10 virus particles.

Base Sequence↗