Browsing by Author "Kar, Anita"

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    Cold-induced alteration in the global structure of the male sex chromosome of In1BM2(reinverted) of Drosophila melanogaster is associated with increased acetylation of histone 4 at lysine 16.
    (2008-12-17) Kulkarni-Shukla, S; Barge, A P; Vartak, R S; Kar, Anita
    In Drosophila melanogaster, dosage compensation occurs through hypertranscription of sex-linked genes in males. The hypertranscription involves acetylation of histone 4 at lysine 16 (H4K16) on amale X-chromosome, brought about by a histone acetyltransferase encoded by the dosage compensation gene, males absent on the first (mof). We report a phenomenon in the strain In(1)B(M2)(reinverted) of D. melanogaster where the global structure of the male X-chromosome can be altered at the third instar larval stage through a 4-h cold shock at 12+/-1 degrees C. We show that the cold shock results in a transient hyperacetylation of H4K16 and an increased expression of MOF. Control proteins H4 acetylated at lysine 5, and the dosage compensation gene msl-2, do not show any change in expression after cold shock. Cytology of the male X-chromosome at different time points during cold shock and recovery, suggests that the hyperacetylation of H4 at lysine 16 causes the X-chromosome to corkscrew into itself, thereby achieving the cold-induced change in the higher order structure of the male polytene X-chromosome. Our studies suggest a role for H4K16 in maintaining the structure of the male X-chromosome in Drosophila.
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    A comparative study of the Diagnosis of Pulmonary Tuberculosis using conventional tools and Polymerase Chain Reaction.
    (2006-04) Parekh, Kavita Modi; Inamdar, Vikas; Jog, Anagha; Kar, Anita
    Results: Total cases considered to be positive for tuberculosis by all criteria was 71. PCR detected 98% of ‘culture positive’, 97% of ‘smear positive, culture positive’, and 100% of ‘smear negative’ culture positive samples. PCR was also positive for 86% of smear negative samples, from tuberculosis suspects diagnosed on the basis of other routine diagnostics and supporting clinical evidence. Seventeen samples were positive only by PCR but based on clinical parameters only 7 were considered as true positives. The sensitivity of PCR was 91.5% compared to 51% for smear microscopy and 68% for sputum culture. This was due to the fact that PCR could pick up bacterial DNA even from saliva mixed sputum specimens, which are generally not considered appropriate for microbiology. The specificity of PCR (86%) was found to be lower than other diagnostic tests mainly due to lack of a suitable gold standard to assess its efficiency. This is an important limitation in evaluation of the test. Conclusions: PCR using MPB64 primers has potential and can be a useful adjunct to diagnose clinical tuberculosis, particularly in smear negative paucibacillary cases. However, the major limitation of PCR results from the absence of a suitable gold standard by which to evaluate the results.
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    Epidemiology & social costs of haemophilia in India.
    (2014-07) Kar, Anita; Phadnis, Supriya; Dharmarajan, Sumedha; Nakade, Juhi
    India lacks a national policy on the prevention and control of genetic disorders. Although the haemoglobinopathies have received some attention, there are scarce data on the epidemiology of other genetic disorders in India. Haemophilia, an inherited single gene disorder with an incidence of 1 per 10,000 births, manifests as spontaneous or trauma-induced haemorrhagic episodes in patients, progressing to chronic disability and premature mortality in untreated patients or patients with sub-optimal treatment. Although the genetic basis of this disorder has been well studied in India, data on the number of patients, trends of the disorder in India, social costs of the condition and opportunities and competencies for offering genetic counselling through a public health programme have not been reported. This review article summarizes the available Indian data, which show that the country harbours the second highest number of global patients with haemophilia A. The reported number of patients with haemophilia A is 11,586 while the estimated prevalence could be around 50,000 patients. This review also identifies the need to immediately initiate a national programme for haemophilia, with components of prevention, care for patients, surveillance and education and support for families.