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Biomedical subjects

S Krishnan

Publications and source records attributed to S Krishnan.

134 records · Page 8Linked to original sources

Free-choice ethanol consumption by rats: effects of ACTH4-10.

The individual and interactive effects of immobilization stress, ACTH11-24 and ACTH4-10 on the free-choice consumption of ethanol in rats were studied. Stress and ethanol both result in activation of the HPA axis and release of ACTH1-39. The animals were offered a two-bottle choice consumption of 0.2% saccharin and 10% ethanol. They were exposed to immobilization stress or IP injections of ACTH4-10 or ACTH11-24 on an irregular, unpredictable schedule. Stress resulted in a decrease in ethanol consumption during the stress period while ACTH11-24 was devoid of any effect. The ACTH4-10 fragment produced an almost complete block of ethanol consumption during the injection period. Saccharin consumption was not affected by any of the above treatments. These results suggest an important role for ACTH4-10 (produced from ACTH1-39) in ethanol consummatory behavior in rats.

Adrenocorticotropic Hormone↗

Harvesting chemical information from the Internet using a distributed approach: ChemXtreme.

The Internet is a comprehensive resource of chemical information which is at the same time largely unstructured. It provides a wealth of scientific information such as experimental data and requires a suitable automated data mining and analysis tool for its meaningful exploration. The Java based software presented here, ChemXtreme, is developed for harvesting chemical information from the Internet employing the Google API in combination with a distributed client/server text analysis architecture based on JavaRMI. It represents the first and until now the only toolkit for automated structured data retrieval from the Internet which is itself open source. ChemXtreme employs the "search the search engine" strategy, where the URLs returned from the search engine are analyzed further via textual pattern analysis. This process resembles the manual analysis of the hit list, where relevant data are captured and, by means of human intervention, are mined into a format suitable for further analysis. ChemXtreme on the other hand transforms chemical information automatically into a structured format suitable for storage in databases and further analysis and also provides links to the original information source. The query data retrieved from the search engine by the server is encoded, encrypted, and compressed and then sent to all the participating active clients in the network for parsing. Relevant information identified by the clients on the retrieved Web sites is sent back to the server, verified, and added to the database for data mining and further analysis. The distributed further analysis of URLs in a client/server architecture scales very favorably, thus producing only minimal overhead.

Chemistry↗

Bone mass in children with congenital hypothyroidism treated with thyroxine since birth.

To determine whether the large doses of thyroxine treatment early in life adversely affect bone mass, we measured bone mass of 20 congenital hypothyroid (CH) patients (8.4 +/- 2.2 years) who were diagnosed and treated since birth. Starting thyroxine dose and current dose were 8.5 +/- 1.9 micrograms/kg/day and 3.1 + 1.2 micrograms/kg/day respectively. Thyroid function and serum biochemical tests for calcium homeostasis were normal at the time of study. Bone mass was measured by dual energy X-ray absorptiometry. Nine siblings served as controls. The patients' bone mineral density was within the normal range of population controls, and was not different from the sibling controls. The patients also had height-adjusted bone mineral content equal to the expected height-adjusted values in the siblings. Our studies indicate that the large doses of thyroxine therapy for CH do not cause osteopenia in childhood.

Absorptiometry, Photon↗

Immunologic parameters in infective endocarditis: a prospective study.

To evaluate the role of immunoglobulins, complement, circulating immune complexes (CIC), heart antibodies (HAb) and rheumatoid factor (RF) in infective endocarditis, we studied 28 consecutive patients before and after therapy. Statistically significant elevation was seen in IgG (p less than 0.001) and IgA (P less than 0.001) level prior to initiation of therapy as compared to a control group. Following drug treatment a fall was noted in IgA (P less than 0.01) and IgM (p less than 0.01) level as compared to basal values. Low C3 levels were seen in those with renal involvement (p less than 0.05). CIC levels estimated by 4% PEG precipitation assay were found to be elevated in 64% of patients. Patients with shorter duration of illness (less than three months) had higher levels of CIC containing IgG (P less than 0.005), IgA (P less than 0.05) and IgM (P less than 0.05), as compared to those with a longer duration. Initial CIC levels did not predict the clinical course and were found to be of no value in prognosis, although an improvement in congestive heart failure was associated with a rise in C3 (P less than 0.05) and IgM (P less than 0.05) containing CIC and an overall clinical improvement with a rise in IgA (p less than 0.05) containing CIC. There was no statistically significant difference in CIC level, for the entire group studied, before and after therapy. Patients who had rheumatoid factor in their initial serum sample demonstrated a fall in IgG, IgA and IgM containing CIC and a rise in C3 with therapy. The converse was true for those who lacked RF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗