http://nopr.niscair.res.in/handle/123456789/3689 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3751 Title: Effect of gastrointestinal proteases on purified human intrinsic factor-vitamin B₁₂ (IF-B₁₂) complex <br/> <br/>Authors: Srikumar, K; Premalatha, R <br/> <br/>Abstract: Intrinsic factor (IF) from human gastric juice was purified and complexed with vitamin B₁₂ (IF-B₁₂ complex) on Sepharose-vitamin B₁₂ affinity matrix. By labeling studies, using [⁵⁷Co] vitamin B₁₂ and ¹²⁵I, the specific B₁₂ binding activity of IF was found to be 23 μgB₁₂/mg protein, and the molecular size by gel filtration 60 kDa. Proteolysis of the IF-B₁₂ complex by sequential treatment with pepsin, trypsin, α-chymotrypsin and carboxypeptidase A, followed by chromatography of proteolysed complex and IF-B₁₂ showed higher mobility of proteolysed fraction. Gel filtration, however, showed same molecular size for both proteolysed and the IF-B₁₂ complex. On SDS-PAGE, purified IF-B₁₂ appeared as a single band of 60 kDa. The proteolysed complex had higher mobility on SDS-PAGE and did not bind to zirconium phosphate gel. Immunodiffusion with rabbit antisera had positive reaction with IF-B₁₂, but there was no reaction with the proteolysed sample. <br/> <br/>Page(s): 139-142 Sat, 29 Mar 2003 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3750 Title: Liver and colon pro- and anti-oxidant enzyme activities in rats after long-term ethylnitrosourea exposure <br/> <br/>Authors: Silig, Yavuz; Ozdemir, Ozturk; Atalay, Atilla <br/> <br/>Abstract: Liver and colon pro- and anti-oxidant enzyme activities were investigated in rats treated with ethylnitrosourea (ENU) (i.p.) (4 mg/kg body wt) for 6 months. The pro-oxidant enzymes (NADPH cytochrome c reductase, NADH cytochrome c reductase, NADH cytochrome b5 reductase and cytochrome P-4502E1 and the anti-oxidant enzyme, superoxide dismutase (SOD) exhibited significantly increased activity in liver and colon. Glucose-6-phosphate dehydrogenase (G6PDH) and glutathione-S-transferase (GST) showed enhanced activity in liver, but decreased activity in colon. Glutathione peroxidase (GP) and glutathione reductase (GR) activities were significantly increased in colon, but decreased in liver. Catalase (CAT) activity while showed a significant increase in liver, exhibited only marginal increase in colon. Malondialdehyde (MDA) level was significantly elevated in both tissues. <br/> <br/>Page(s): 136-138 Sat, 29 Mar 2003 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3749 Title: Adverse health effects in workers exposed to trace/toxic metals at workplace <br/> <br/>Authors: Mehra, Rita; Juneja, Meenu <br/> <br/>Abstract: Widespread use of metals in industrial activities has enhanced the occupational exposure to toxic metals as well as the health risks of metal hazards to humans. Elemental analysis in human tissues is the most common application of biological monitoring for screening, diagnosis and assessment of such exposures and risk. Among various biopsy materials, blood, hair, nail, teeth and body fluids may be used as bioindicators for this purpose. The present paper deals with the determination of Pb, Cr, Ni, Mn, Fe, Cu and Zn elemental concentration in workers exposed to these metals at workplace by atomic absorption spectrophotometry, with adequate quality control measures using hair as biopsy material. The study group includes the male workers such as welders, foundry man, fitter, hammer man, machine man, cupola man etc., besides office workers of locomotive workshop in Ajmer and surrounding areas exposed to different metals. Age and sex matched controls of persons working in the same area of work in offices etc. and not exposed to metal pollution were selected for valid comparison. It is proposed to validate the use of hair as a biological marker for assessing metal body burden of workers. In our study significant correlations have been found between skin disease and Cr, Mn, Fe, Cu; chest pain and Pb; hypertension and Cu, Mn; mental stress and Mn, Ni, Cu, Zn; liver problem and Ni; indigestion and Cr; Ni, diabetes and Cr, Mn, Ni; tuberculosis and Zn; breathing trouble and Cr, Mn, Fe, Ni, Zn. The advantages of choosing hair as a biopsy material are also given. <br/> <br/>Page(s): 131-135 Sat, 29 Mar 2003 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/3748 Title: Interaction of water vapour with twenty different poly-L-amino acids and their excess hydration in presence of sodium chloride <br/> <br/>Authors: Ghosh, N; Dutta, P; Mahapatra, P; Das, K P; Chattoraj, D K <br/> <br/>Abstract: Using the isopiestic vapour pressure technique, the magnitudes of excess binding of water and NaCl per mole of twenty different poly-L-amino acid residues, respectively in the presence of different bulk molefractions (X₂) of NaCl have been evaluated from the mathematical expressions for the Gibbs surface excesses. At certain high ranges of NaCl concentration, the plot of -ɼ₁² vs. X₁/X₂ becomes linear, so that moles of water and NaCl, respectively bound per mole of amino acid residue can be evaluated. ɼ₁² is the excess moles of H₂O per mole of amino acid residue and X₁ and X₂ stand for mole fractions of the water and NaCl, respectively in the sample system. Also, using the integrated form of the Gibbs absorption equation, the values of standard free energy change (ΔGº) for the excess adsorption of NaCl per kg of poly-L-amino acids have been evaluated. These values are all positive as a result of positive excess hydration of polyamino acids. The standard free energy of excess hydration ΔGº_hy (equal to -ΔGº) is negative due to spontaneous excess hydration of polyamino acid in the presence of a salt. <br/> <br/>Page(s): 122-130 Sat, 29 Mar 2003 22:58:59 GMT