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Biomedical subjects

M S Rajagopalan

Publications and source records attributed to M S Rajagopalan.

At least 19 recordsLinked to original sources
PubMed1992

In vivo exposure to ultraviolet radiation enhances pathogenic effects of murine leukemia virus, LP-BM5, in murine acquired immunodeficiency syndrome.

LP-BM5 murine leukemia virus (MuLV) induces an immunodeficiency syndrome (MAIDS) in C57BL/6 mice which resembles immunological abnormalities observed in early stages of human AIDS. In our study, MAIDS virus-infected mice were exposed to low doses of ultraviolet radiation (UVR) before and after virus inoculation and compared with MAIDS-infected but not UVR-exposed mice. In all tested parameters (blood IgM levels; mitogenic responses to PHA, ConA, LPS and anti-mu; MLR; antigenic response to SRBC; enlargement and histopathologic changes of the spleen) we observed the same trend: changes due to MAIDS infection were more pronounced in the UVR-exposed group than in the unexposed group. Statistically significant differences between these two groups were seen for mitogenic responses at two different time points after virus inoculation. These results demonstrate that in vivo UVR exposure enhances the immunosuppressive effects of a retroviral infection. UVR exposure may affect the progression of AIDS in a similar manner.

Animals↗
PubMed1990

Serial passage of west-European sporadic non-A non-B hepatitis in rhesus monkeys by inoculation with fecal extracts.

An experimental model of sporadic non-A non-B hepatitis involving a Fab nonimmune binding activity in stools was established in the rhesus monkey. The first animal was inoculated intravenously with a stool extract from a French patient who had never left the country and in whom post-transfusion hepatitis was excluded. Four passages were performed, and the infection was transmitted by parenteral as well as the oral routes by inoculation of stools or liver extracts. Infection led in three monkeys to reversible hepatocyte injury manifested by a transitory increase in serum aminotransferases. The other three animals, in which persistently high levels of aminotransferases was observed, were sacrificed on day 60 after inoculation. The incubation period, as evidenced by elevation of aminotransferases was about 3 to 4 weeks. The infectious agent was transitorily present in the stools before aminotransferase elevation. The presence of the infectious agent in the stools was correlated with the nonimmune Fab binding activity.

Adult↗
PubMed1989

Isolation and immunological characterization of a group of new B lymphomas from CBA mice.

We have isolated and characterized a new series of B lymphoma which occurred spontaneously in a group of CBA/N mice that were transferred with spleen or lymph node cells from 24-month-old CBA/Ca mice. Tumor cell lines from six CBA/N mice that received spleen cells were rescued and designated as BKS-2, BKS-3, BKS-4, BKS-5, BKS-6, and BKS-7. Also, tumor cells from a recipient of lymph node cells were rescued and the resulting cell line was designated BKL. These tumor cells expressed membrane immunoglobulin (mu, kappa), major histocompatibility complex Class I and Class II molecules, B220, Lyb8, Fc receptors, J11d, interleukin 2 receptors, and Ly1. All of the tumors did not express the T cell specific markers Thy 1.2, L3T4, and Lyt2.1. They appeared to be clonal in origin, since they exhibited common rearrangements at both heavy and light chain immunoglobulin loci. Phenotypically, these lymphomas appeared to be analogous to immature B cells. Also, these lymphomas displayed different functional reactivities when treated with various B cell mitogens and growth factors in vitro. Anti-mu antibodies which normally induce B cell growth inhibited the proliferation of these lymphoma cells in vitro, whereas they responded to lipopolysaccharide, T cell-derived growth factors, and interleukin 5 by enhanced proliferation. These tumor cells expressed constitutively high levels of c-myc mRNA.

Animals↗
PubMed1989

Sub clinical infection and the relative risk of developing leprosy: a statistical approach.

Subclinical infection in contacts of leprosy patients was identified by FLA-ABS test and Serum Antibody Competition Test (SACT). The risk of developing leprosy and the confidence intervals were worked out. The importance of expressing the risk ratio and confidence interval of the tests is brought out. This method is a useful adjunct to the routine statistical methods in epidemiological studies.

Antibodies, Monoclonal↗
PubMed1987

In situ hybridization and immunocytochemistry for improved assessment of human immunodeficiency virus cultures.

The authors characterized the early intracellular events involved in human immunodeficiency virus (HIV) replication after in vitro inoculation into cultures of susceptible human T-cell lines and phytohemagglutinin-stimulated peripheral-blood mononuclear cells (PMCs). Within 24 hours of infection, in situ hybridization with HIV DNA probe detected cytoplasmic viral RNA. Viral core antigen was detected in infected cells over the subsequent two to ten days by means of an immunocytochemical assay employing monoclonal antibodies. Several days later, cell-free virus was detected by both reverse transcriptase assay and a p25gag antigen-capture assay. When these methods were applied to monitor cultures of ten sero-positive persons' PMCs, a similar progression of virus replication was apparent: cytoplasmic viral RNA was detected in infected PMCs by day 3, with the subsequent appearance of intracellular viral proteins (days 6-9) and cell-free virus (days 12-21). In situ hybridization and immunocytochemistry offer complementary, sensitive, and specific approaches for monitoring the early stages of acquired immune deficiency syndrome virus replication in vitro.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Interaction of aflatoxin and hepatitis B virus in the pathogenesis of hepatocellular carcinoma.

Aflatoxin-B1 (AFB) and chronic hepatitis B virus (HBV) infection epidemiologically correlate with the geographic distribution of hepatocellular carcinoma (HCC). Integration of HBV DNA into the cellular genome of HCCs and the in vivo formation of adducts between AFB and nucleic acids lead us to suggest that hepatocytes with integrated HBV DNA preferentially accumulate AFB; the AFB-adducts formed may then initiate cell transformation by modifying the expression of critical host genes. The altered molecular biology of liver cells in HCC is evidenced by the fact that HBV does not replicate in HCC tissues or cell lines. The effect of AFB on the expression of cellular genes such as endogenous retrovirus(es) and possibly cellular oncogene(s) can be analyzed in HCC cell lines with and without integrated HBV DNA. In addition, human HCC tissues can be probed for HBV sequences and AFB-DNA adducts at the single-cell level. The presence of HBV and AFB can be correlated with the expression of putative transforming genes, providing a new insight into the interaction between liver cells, HBV and AFB in the pathogenesis of HCC.

Aflatoxin B1↗
PubMed1982

Sensitivity of passive bacterial agglutination for detection of hepatitis B surface antigen.

The sensitivity of passive bacterial agglutination (PBA), i.e., the agglutination of Staphylococcus aureus coated with antibodies to hepatitis B surface antigen by hepatitis B surface antigen, was assessed by testing reference panel no. 3A sera (Bureau of Biologics, U.S. Food and Drug Administration). Of the 23 samples containing hepatitis B surface antigen, 18 were positive by PBA. Sera from 100 healthy adults were tested by PBA and reversed passive hemagglutination. Four sera were positive by both methods. One additional sample was positive only by PBA; if one assumes that it was a false-positive result, the rate of false-positive reactions was only 1%.

Agglutination↗
PubMed1981

Abnormalities of the immune system in patients with chyluria.

A study of the immune system in 11 patients with chyluria showed lymphocytopenia, decrease in T cells, a low serum IgA concentration and suppression of delayed hypersensitivity responses to intradermally injected antigens. The similarity of chyluria to intestinal lymphangiectasia and thoracic duct fistula suggests that the immune deficiency may be due to loss of lymph in the urine.

Adult↗
PubMed1979

Epidemic hepatitis B caused by commercial human immunoglobulin.

An epidemic of acute hepatitis B followed the administration of human immunoglobulin to members of the staff of a mission hospital in India and their families. Jaundice developed in 123 (38%) of 325 persons inoculated. Hepatitis-B surface antigen was detected in three of the batches of immunoglobulin which were available for testing.

Counterimmunoelectrophoresis↗
PubMed1977

Plantar ulcers with osteomyelitis underneath. A bacteriological study.

39 consecutive cases of plantar ulcers with underlying chronic osteomyelitis admitted in the Sacred Heart Hospital during 1975/1976 were studied for the infecting organisms and their sensitivity to easily available antibiotics. Single organism was iasolated in only 10 cases, the infection in the rest being a mixed one. The commonest organisms were Staphylococcus, Streptococcus and Proteus mirabilis. In a few cases Pseudomonas and E-Coli were also isolated. Chloramphenicol was the most effective antibiotic in general and Streptomycin the least. 70% of the staphylococcus strains isolated were found to be resistant to Penicillin. Empirical use of antibiotics especially Penicillin and Streptomycin is hence deprecated.

Adolescent↗
PubMed1976

Synthesis of 18-substituted steroids Part II (1). Improvements in the preparation of 18-hydroxyprogesterone.

18-Hydroxyprogesterone is conveniently prepared from 3beta-acetoxypregn-5-en-20beta-ol by a modified route. 3beta-Acetoxy-18-iodopregn-5-en-20-one, obtained by the hypoiodite-photolysis procedure and oxidation, is treated with methanolic silver acetate to give the 18, 20-epoxy-20-methoxy derivative, which crystallises directly without need for chromatography. Hydrolysis of the 3-acetate, and a modified Oppenauer oxidation, gave 18-hydroxy-progesterone in 24% over-all yield.

Chemical Phenomena↗