Developmental exposure to lead and late life abnormalities of nervous system.

Role of developmental exposure to environmental agents in altering the disease process is well known. Exposure to chemical agents at critical periods of development may cause some permanent changes in the functioning of various vital systems including the nervous system in the organisms. It is not surprising to see an extensive response due to exposure to chemical agents early in life as the organ systems are more vulnerable to chemical insults during developmental stages. In some cases the response to low level environmental insults may not be obvious until adult or old age. Results from several studies have shown such latency in response to the nervous system leading to neurodegeneration in old age. Studies conducted in murine and primate models provided ample evidence for the association of developmental exposure to low levels of heavy metal lead (Pb) and Alzheimer’s disease-like pathology during senescence. It is not clear about the reasons behind such response; however, the contribution of epigenetic mechanisms could explain the role of early events in life in inducing the late life abnormalities of nervous system. It is possible that environmental agents epigenetically modulate the gene regulation to persist the response silent for a long period of time and to result pathological outcomes significantly later in life. This article will summarize the association of early life exposure to environmental agents and late-life abnormalities with an emphasis on developmental exposure to Pb and neurodegeneration in old age.

A Coverage Evaluation Survey of JE Vaccination in Two Districts of Karnataka.

A coverage evaluation survey was conducted in Mandya and Koppal districts of Karnataka state following the Japanese Encephalitis (JE) vaccination campaign. The purposes of the survey were to assess coverage of children in target age group by JE vaccination and to assess adverse events following immunisation against JE, the knowledge of health care providers and community about JE & mass vaccination for JE. The study design consisted of both quantitative and qualitative methods. The quantitative data was used to know the coverage levels for children. The qualitative data collected through interviews of head of the family in the sample households, selected health care workers using a structured pretested questionnaire. The standard cluster sampling method was used for selecting the sample of children to be evaluated. In Mandya district the evaluation showed 92 % coverage in the selected sample of 313 children against the reported 83.85 %. In Koppal district the evaluation showed 70 % coverage, among the selected sample of 251 children, against the reported coverage of 69.8 %. The incidence of adverse events was 4% in Mandya sample and 6.37 % in Koppal sample. In Mandya district, about 42 % of households had knowledge of JE. About 68 % of households had prior knowledge of the immunization day. In Koppal district, the survey has revealed that only 19.85 % of the heads of household had the knowledge of JE and 48.53% had the knowledge of JE vaccination before the day of vaccination campaign.