Biomedical subjects
Publications and source records attributed to L M Srivastava.
The commonly occurring phenotypes and some rare variants of C3 were studied in a North Indian population. Based on known gene frequencies, the Indian population seemed more akin to Mongol, African, and Afghan populations than to Caucasians.
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The dietary stress conditions such as starvation influenced Na+K+-ATPase activity which increased steadily above normal fed levels between the starvation periods of 24--48 hr. Also, an increased enzyme level was observed in alloxan diabetic rats and administration of insulin to diabetic rats led to a tendency towards a lowering of Na+K+-ATPase. Adrenalectomy brought about a lowering of Na+K+-ATPase activity from those of normals while the administration of hydrocortisone induced an enhancement. The results indicate that both starvation and diabetic conditions might cause a stress-like activation of adrenal cortex resulting in increased levels of glucocorticoids which in turn activate the intestinal Na+K+-ATPase activity.
Ultrastructural transformation of mitochondria in the cotyledons of dry and germinating seeds of Vigna sinensis from the 'orthodox' to 'condensed' forms is coupled with an increasing rise in the specific activity of succinic dehydrogenase (SDH). Apparently, the transformation of mitochondria to the 'condensed' form associated with the utilization of substrate which is reflected in the rise in enzyme activity. During the process of germination, the mitochondria of the cotyledonary cells undergo three different phases namely, (1) activation phase, (2) preparatory phase, and (3) multiplication phase.
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Sera from 21 cases of prolonged apnoea which showed normal phenotype (UU) on the basis of dibucaine and fluoride inhibition were re-examined by replacing the substrate benzoylcholine with succinylcholine (suxamethonium). 9 samples had normal enzyme activity but low dibucaine number (DN = less than 20) indicating the atypical variant; 6 sera showed no detectable enzyme activity. The remaining 6 samples had enzyme activity and DN comparable with healthy controls. The occurence of new variants of serum cholinesterase sensitive only to succinylcholine is suggested.
The distribution of phenotypes C3, Ff and Bg was investigated in sera of patients with Down's syndrome, oligophrenia, Wilson's disease and heart infarct. Quantitative determination of the concentration of C3 and C4 components of human complement was also carried out in these patients. The results are compared to healthy controls and are discussed with already reported data from other authors. Despite differences in the percentage distribution of various phenotypes in the patients' sera as compared to that of the controls, no statistically significant association could be established.
Disaccharidase activity has been shown to be increased in human diabetics. Diabetics controlled on diet therapy showed no change in disaccharidase activity while two diabetics controlled on insulin or insulin-producing drug, glibenclamide, showed a fall in disaccharidase values toward normal. Possible causes for the increased disaccharidase activity in diabetes are discussed.
Serum lactate dehydrogenase isoenzymes, creatine phosphokinase and aldolase activity were determined in healthy control subjects and in lepromatous and tuberculoid leprosy patients from Ethiopia. Sera from lepromatous patients showed a higher total LDH activity compared with control subject. The values for tuberculoid leprosy patients were similar to those of controls. Sera from normal healthy controls showed a higher proportion of LDH-H form (72%) while lepromatous leprosy patient's sera exhibited a higher proportion of LDH-M form (55%). Tuberculoid leprosy patients showed a pattern similar to that of healthy controls. A possible significance of these observations is discussed. No significant variations were observed in fructose-1,6-diphosphate aldolase activity within the different types of disease and controls. Although creatine phosphokinase levels in different types of leprosy decreased significantly from those of normal healthy, it falls within the reported variation of the activity in normal sera.
Various classes of immunoglobulins (IgA, IgM, IgG, IgD and IgE), complement components (C3 and C4) and C-reactive protein (CRP) were estimated in sera from normal healthy controls and leprosy (lepromatous and tuberculoid) patients from Ethiopia. Higher levels of IgA, IgM, IgG and IgD were found in lepromatous leprosy compared with normal healthy people while in tuberculoid leprosy only IgM, IgG and IgD levels were increased. Borderline leprosy patients showed increase in IgG level only. Although an increase in IgE was noted in lepromatous leprosy, it was not significant; the variations in IgE levels could be due to different socioeconomic background and exposure to intestinal parasites. C3 component was significantly reduced in leprosy patients compared with healthy controls while no difference in C4 component was observed. The results point towards an involvement of the "alternate pathway". A positive test against C-reactive protein antiserum was given by about 20% of the normal healthy controls while more than 60% lepromatous and tuberculoid leprosy patients were CRP positive. The results are discussed in relation to the status of immunoglobulins and complement components in leprosy and possible factors (environmental and genetic) which might affect them.
148 members from 30 families (64 children) from Ethiopia, where one of more persons were affected with leprosy, were investigated for genetic polymorphism of C3, serum concentration of ss1C/ss1A-globulin and immunoglobulins A, G and M using high voltage agarose electrophoresis, immunoelectroassay and single radial immunodiffusion techniques respectively. The results are compared with related healthy controls. No association between C3 phenotypes and leprosy could be established through family studies. C3 concentration was, however, lower in leprosy patients. Difficulties and drawbacks of such studies with small families are discussed.
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The serum levels of IgA, IgM, IgG and IgD were determined in patients with Down's syndrome (69 cases), Oligophrenia (101 cases) and Morbus Wilson (18 cases). In sera from Down's syndrome patients a significant increase in the levels of IgA, IgG and IgD were found. IgM levels were identical to those of healthy controls. The immunoglobulin levels in both the oligophrenia and Wilson's disease patients were not different from those of controls.
A simple and rapid method for the estimation of the hydrolysis of succinyl choline by serum cholinesterase variants is described. Succinyl choline, as substrate for the enzyme assay, has many advantages over other substrates (acetyl choline, benzoyl choline and butyryl choline) which have no clinical application. Choline, the hydrolytic product of succinyl choline, is oxidized to betaine aldehyde by choline oxidase (EC 1.1.99.1), a rat liver mitochondrial preparation; this is coupled to the reduction of cytochrome c which is measured at 550 nm. Fifty normal sera (UU), 17 heterozygous (UA) and 8 atypical (AA) were tested with this method, and on the basis of resistance to dibucaine (Cinchocain; Kalow, W. & Genest, K. (1957) Canad. J. Biochem. Physiol. 35, 339-346) inhibition, three distinct groups could be established using succinyl choline as substrate. These results are comparable with the standard optical method of Kalow & Genest (cf. above) using benzoyl choline as substrate.