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Biomedical subjects

S Sivaram

Publications and source records attributed to S Sivaram.

14 recordsLinked to original sources

Community prevalence of hepatitis B infection and modes of transmission in Tamil Nadu, India.

BACKGROUND AND OBJECTIVE: There have been very few community based studies on prevalence of hepatitis B virus (HBV) infection in India. We undertook this study to determine the prevalence of HBV infection in a southern State of India, Tamil Nadu and to describe the important factors related to transmission of the virus in the community. METHODS: Analysis of stored blood samples from a representative population of Tamil Nadu from an earlier community cluster survey on sexually transmitted diseases (STD) prevalence using proportionate to population size (PPS) technique was done. Serum markers of HBV viz., hapatitis B surface antigen (HBsAg), hepatitis B e antigen (HBe Ag) and antibody to surface antigen (anti-HBs) were performed. RESULTS: 1981 subjects were screened in the study. HBsAg prevalence was 5.7 per cent (CI 4.6- 6.8) with 23.5 per cent (25/106) of these having positive HBe-antigen. Community seroprevalence (HbsAg + anti-HBs) of hepatitis B infection was 27.4 per cent (CI: 25.3-29.5) with the highest prevalence of 32.7 per cent (CI: 30.2-35.2) noted in the 15-20 yr age group. Significant independent association (OR 1.4; P=0.006) was detected with family history of exposure to HBV infection by logistic modeling. Other risk factors noted to have significant association were use of disposable needles during injection (OR 0.5; P=0.02) in men, smoking (OR 3; P=0.04) and use of condom (OR 0.6; P=0.08) in women. INTERPRETATION AND CONCLUSION: This community based study shows a high prevalence of hepatitis B infection in the state of Tamil Nadu with the highest prevalence being in the younger (15-20 yr) age group. High prevalence rate in childhood with e-antigenemia seen in 23.5 per cent of HBsAg positive subjects suggest childhood transmission. Poor injection practices and high-risk sexual behavior were found to be additional risk factors for transmission of the disease in the community.

Adolescent↗

Training outreach workers for AIDS prevention in rural India: is it sustainable?

Through a process of community diagnosis and participation, a non-governmental organization in rural Karnataka state in India selected and trained peer outreach workers to implement and sustain AIDS prevention education activities. This activity was part of a larger AIDS education project that aimed at creating awareness and promoting risk-reducing behaviours in the community. This paper describes efforts of the project to identify and train peer educators during its implementation phase and discusses strategies used to facilitate sustainability. We evaluate the impact of these efforts by conducting an analysis in the project area 2 years after the end of the project. The findings reveal generalized interest among rural communities in HIV prevention issues. The project originally conducted an extensive survey to understand community organization and composition, which helped to identify potential partners and peer educators. Training peer educators was a multi-step process, and one with high attrition. While individual peer educators were an excellent resource during the life of the project, peer educators affiliated with village level institutions had the interest, access to resources and willingness to sustain project efforts. However, the sustainability of their efforts was associated with the quality of interactions with the project implementation team, the strength and leadership of their own institutions, the perceived benefits of implementing AIDS education activities after project life and the gender of the outreach worker. Non-sustainers did not have an organizational structure to backstop their work, were often poor and unemployed persons who later found gainful employment, and overwhelmingly, were female. We present a conceptual model based on these findings to help future projects plan for and achieve sustainability.

Community Health Workers↗

Brefeldin A inhibits the antiviral action of interferon against encephalomyocarditis virus.

Brefeldin A (BFA), a unique fungal metabolite of a 13-membered lactone ring, exhibits various biological actions, including antitumor, antifungal and antiviral activities. In the present study, mouse LB cells were treated with various concentrations of interferon (IFN) and/or BFA overnight and infected with encephalomyocarditis virus (EMCV) after removal of IFN and BFA. Doses of BFA which neither inhibit the metabolism of the cell nor the infectivity of EMCV, decreased the IFN-induced antiviral activity against EMCV as demonstrated by virus titer from supernatants. Since 2-5A synthetase and double-stranded RNA (dsRNA)-dependent protein kinase (PKR) have been suggested to be involved in the antiviral action of IFN against EMCV, their activities were investigated in LB cells after BFA treatment. Northern blot analysis and in situ hybridization showed a decrease (2-3-fold) in the mRNA of 2'-5' oligoadenylate (2-5A) synthetase after BFA treatment. BFA also inhibited the activity of 2-5A synthetase, 2-5A dependent RNase and phosphorylation of PKR in cellular extracts, indicating that BFA may be exerting its inhibitory effect both at the transcriptional and post-transcriptional levels. This study reports a new biological action of BFA, demonstrating that BFA antagonized the antiviral action of IFN by inhibiting IFN-induced enzymatic pathways. These studies also suggest that both 2-5A and PKR are important in the antiviral activity of IFN against EMCV.

2',5'-Oligoadenylate Synthetase↗

Differentiation between stains of human blood and blood of monkey.

The precipitin tube test fails to differentiate between blood stains of closely related animals such as man and monkey because of the close similarity between antigenic determinants of serum proteins of such closely related species. The quantitative precipitin technique cannot be applied to forensic work. This paper cites a case where definite opinion on the species of origin of some blood stains suspected to have come from a monkey was possible. In the method used, extracts of the questioned stain were tested with similar extracts of known human and known monkey blood stains against human globulin antiserum, by comparative double diffusion method in agar gel on microslides.

Animals↗