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Biomedical subjects

G Jayashree

Publications and source records attributed to G Jayashree.

7 recordsLinked to original sources
PubMed2005

Structural basis for the energetics of jacalin-sugar interactions: promiscuity versus specificity.

Jacalin, a tetrameric lectin, is one of the two lectins present in jackfruit (Artocarpus integrifolia) seeds. Its crystal structure revealed, for the first time, the occurrence of the beta-prism I fold in lectins. The structure led to the elucidation of the crucial role of a new N terminus generated by post-translational proteolysis for the lectin's specificity for galactose. Subsequent X-ray studies on other carbohydrate complexes showed that the extended binding site of jacalin consisted of, in addition to the primary binding site, a hydrophobic secondary site A composed of aromatic residues and a secondary site B involved mainly in water-bridges. A recent investigation involving surface plasmon resonance and the X-ray analysis of a methyl-alpha-mannose complex, had led to a suggestion of promiscuity in the lectin's sugar specificity. To explore this suggestion further, detailed isothermal titration calorimetric studies on the interaction of galactose (Gal), mannose (Man), glucose (Glc), Me-alpha-Gal, Me-alpha-Man, Me-alpha-Glc and other mono- and oligosaccharides of biological relevance and crystallographic studies on the jacalin-Me-alpha-Glc complex and a new form of the jacalin-Me-alpha-Man complex, have been carried out. The binding affinity of Me-alpha-Man is 20 times weaker than that of Me-alpha-Gal. The corresponding number is 27, when the binding affinities of Gal and Me-alpha-Gal, and those of Man and Me-alpha-Man are compared. Glucose (Glc) shows no measurable binding, while the binding affinity of Me-alpha-Glc is slightly less than that of Me-alpha-Man. The available crystal structures of jacalin-sugar complexes provide a convincing explanation for the energetics of binding in terms of interactions at the primary binding site and secondary site A. The other sugars used in calorimetric studies show no detectable binding to jacalin. These results and other available evidence suggest that jacalin is specific to O-glycans and its affinity to N-glycans is extremely weak or non-existent and therefore of limited value in processes involving biological recognition.

Adjuvants, Immunologic↗
PubMed2003

Anti-oxidant activity of Centella asiatica on lymphoma-bearing mice.

Oral treatment with 50 mg X kg(-1) day(-1) of crude methanol extract of Centella asiatica for 14 days significantly increased the anti-oxidant enzymes, like superoxide dismutase (SOD), catalase and glutathione peroxidase (GSHPx), and anti-oxidants like glutathione (GSH) and ascorbic acid decreased in lymphoma-bearing mice.

Administration, Oral↗
PubMed1996

Metabolism of proteins and glycoproteins in tumour bearing mice treated with Aeromonas L-asparaginase.

L-asparaginase, isolated in our laboratory, from Aeromonas had been found to be antileukaemic. In the present study, changes in the levels of proteins and glycoproteins in leukaemic mice and under treatment with Aeromonas L-asparaginase have been compared. Levels of protein bound hexose, fucose and sialic acid which were increased during leukaemia attained normal levels when treated with L-asparaginase. The increased blood urea level declined significantly during enzyme therapy. Effects of L-asparaginase are compared with 'Leunase', a commercially available drug used in the treatment of leukaemia.

Aeromonas↗
PubMed1991

Acute renal failure in asphyxiated newborns.

The study was undertaken to evaluate the occurrence of renal failure following perinatal asphyxia in the newborns. Thirty newborns with severe birth asphyxia were included in the study along with 30 normal newborns who comprised the control group. Any neonate presenting with oliguria or blood urea more than 40 mg/dl or creatinine more than 1 mg/dl was subjected to a fluid and diuretic challenge. If oliguria or renal dysfunction persisted then the child was labelled as renal failure and these subjects were further investigated. It was observed that 43% of asphyxiated babies developed acute renal failure (ARF); 69.2% babies had oliguric renal failure. While no significant correlation could be seen between Apgar scores at 5 and 10 min and development of ARF, a significant relationship was seen between hypoxic-ischemic encephalopathy and ARF. Patients with oliguric ARF carried a poorer prognosis as compared to non-oliguric ARF.

Acute Kidney Injury↗
PubMed1991

Renal dysfunction in septicemic newborns.

The study was undertaken to assess the association and incidence of acute renal failure (ARF) in septicemic neonates. Thirty neonates with septicemia formed the subject matter. Neonates with renal dysfunction were labelled as ARF patients after non responsiveness to a fluid and a diuretic challenge. Renal function tests were also evaluated. Nearly 15% neonates with septicemia developed ARF which was predominantly oliguric in type. The mortality rate in the septicemic neonates with ARF was significantly high. Further the mortality in neonates with oliguric ARF was significantly higher than those with non-oliguric ARF.

Acute Kidney Injury↗