Ground water geochemistry of Ballia district, Uttar Pradesh, India and mechanism of arsenic release.

Threat to human health worldwide due to the natural contamination of arsenic in ground waters has led to extensive studies on factors controlling the distribution of arsenic and conditions leading to arsenic mobilization in different arsenic contaminated areas. Another aspect of the arsenic crisis, especially in South Asia, is the degree of spatial variability of ground water arsenic concentrations. Thus it becomes necessary to study the source and the processes involved in arsenic mobilization into ground water under such conditions. An arsenic contaminated area namely, Ballia district of UP was chosen for this study. A set of 56 samples were collected from India Mark II hand pumps (30-33 m depth) thrice in a year namely pre-monsoon (April '07), monsoon (July '06) and winter seasons (December '06). Nine samples were also collected from deep bore well hand pumps (66-75 m) to study the difference in geochemistry with the shallow pumps. Various water quality parameters like As(III), As(V), sulfate, nitrate, phosphate, bicarbonate, ammonia, were determined. Arsenic concentrations ranged from 0 to 468 microg L(-1) in ground water collected from depths of 30-33 m. In the deeper wells (66-75 m), arsenic concentrations ranged from 12 to 20 microg L(-1). Most samples contained both As(III) and As(V) and the concentration of As(III) was generally equal/higher than As(V). Not much variation of arsenic concentration was observed when sampled in summer, monsoon and winter seasons. Correlation studies among various water quality parameters revealed that reductive dissolution of FeOOH was the most probable mechanism for release of arsenic.

Evaluation of two commercial field test kits used for screening of groundwater for arsenic in Northern India.

In this study two relatively new arsenic field kits, namely Wagtech Digital Arsenator (WFTK) and Chem-In Corp field test kit (CFTK) for arsenic were evaluated. The response of the two field test kits to known standards (Both As(III) and As(V)) is detailed. In addition around 157 arsenic-contaminated field samples obtained from various locations of Ballia and Kanpur districts, U.P., India were tested using the two kits and the results were compared with the laboratory-based colorimetric method (silver diethyldithiocarbamate method, SDDC). The concentration of arsenic in the 157 samples ranged from 0 to 468 microg l(-1). WFTK is seen to be suitable for measuring arsenic concentration <5-100 microg l(-1) using the digital meter. CFTK was not able to detect As(V) and its usage is cautioned in Uttar Pradesh where As(V) is seen to occur in appreciable concentrations. The Pearson's correlation between the silver diethyldithiocarbamate method and WFTK was found to be 0.87 and for the corresponding correlation with CFTK was 0.41 in the concentration range used in this study. Spearman's rank correlation coefficients comparing the WFTK and CFTK to laboratory measurements in the concentration range of 0-100 microg l(-1) were 0.95 (p<0.001) and 0.64 (p<0.001) respectively.

Modification of arginine residues at the substrate binding site of yeast glutathione reductase.

Yeast glutathione reductase (GR) was inactivated by phenylglyoxal (PG), which specifically modifies arginine residues of the enzyme. Inactivation followed psuedo-first order rate kinetics. There was no reversible complex formation prior to inactivation. Analysis of the kinetic data showed the order of reaction to be unity with respect to the modifier. Inactivation of GR was completely prevented by the presence of oxidised glutathione (GSSG), whereas NADP gave only partial protection. Stoichiometric studies showed that around four arginine residues per subunit were modified by PG in the absence of GSSG, whereas only one was modified in its presence. From these observations, it is concluded that essential arginine residues are present at the substrate binding site.

Modification of an essential amino group of glutathione reductase from yeast by pyridoxal 5'-phosphate.

Yeast glutathione reductase is inactivated by pyridoxal 5'-phosphate (PLP). The reactivation of the enzyme by dilution as well as a characteristic absorption peak at 325 nm exhibited by NaBH4-reduced-PLP modified enzyme show that the inactivation is due to the specific modification of the epsilon-amino group of lysine residue. The maximum of 70% inactivation was observed at 7mM PLP and the equilibrium was reached within 3 min. Kinetic and equilibrium analysis of inactivation data derived at different PLP concentrations showed that a noncovalent intermediate is formed prior to inactivation. From the studies on the effect of pH on the inactivation rate, the pKa of epsilon-amino group of the reactive lysine residue was calculated to be 7.3. Among various protecting agents tried, only NADP was found to be effective. The apparent stoichiometry of the reaction was one to one as the incorporation of 0.65 mole PLP/mole of enzyme led to 70% inactivation at saturating PLP concentration.

Screening of tropical wood-rotting mushrooms for copper biosorption.

Fruiting bodies (mushrooms) of nine nonedible macrofungi were screened for copper(II) uptake potential. The maximum uptake potentials (Q(infmax)s) derived from equilibrium studies indicated that all nine species exhibited higher Q(infmax)s at pH 4.0 than that of Filtrasorb-400, a generally used adsorbent for metal removal. Wide variation in Q(infmax) was observed among the species and ranged from 0.048 to 0.383 mmol per g of sorbent. The uptake capacity of Ganoderma lucidum, which exhibited the highest Q(infmax), was higher than those of other microbial biosorbents reported in the literature.

Leucocyte metabolism in maternal and cord blood in intrauterine malnutrition (IUM).

Leucocyte metabolism was studied in maternal and cord blood in normal term pregnancies with and without intrauterine malnutrition (IUM). It was observed that hexose monophosphate shunt activity was significantly reduced in the leucocytes of both the mothers and infants with IUM. Glycogen content in the cord leucocytes was also reduced, indicating a reduction in the defense mechanism in the infants. Protein/DNA ratio was significantly increased in both the maternal and cord leucocytes in IUM. It would appear that IUM, especially in a high-risk population, can be predicted in early third trimester by using maternal leucocyte protein/DNA.

Glucose and free fatty acid response to intravenous glucose during pregnancy.

Intravenous glucose tolerance tests were performed in undernourished and well-nourished normal pregnant women and for toxemic women near term. Both blood glucose and free fatty acid levels were analyzed, till 90 min after glucose load. The results suggested that glucose response to intravenous load was poor both in normal undernourished and toxemic women as compared to well-nourished women. However, the free fatty acid pattern was abnormal only in toxemic women in that the levels free fatty acid levels were analyzed, till 90 min after glucose load. The results suggested that glucose response to intravenous load was poor both in normal undernourished and toxemic women as compared to well-nourished women. However, the free fatty acid pattern was abnormal only in toxemic women in that the levels free fatty acid levels were analyzed, till 90 min after glucose load. The results suggested that glucose response to intravenous load was poor both in normal undernourished and toxemic women as compared to well-nourished women. However, the free fatty acid pattern was abnormal only in toxemic women in that the levels did not return to basal value even after 90 min of glucose load. Since human placental lactogen in pregnancy is known to regulate free fatty acid release for energy utilization, its deficiency in toxemia (commonly known to occur) could be implicated in the abnormal free fatty acid response seen in this investigation.

Significance of amniotic fluid glucose in pregnancy.

Amniotic fluid glucose values were measured in 285 women with normal and abnormal pregnancies. A progressive decrease in glucose values was observed with advancing gestation. Complications in pregnancy did not influence the amniotic fluid glucose value for the given gestational age. In patients with diabetes, very high levels were found, but these progressively decreased with advancing gestation. Since abnormal conditions in pregnancy, other than diabetes, do not affect the amniotic fluid glucose level, it seems to be a reliable tool in assessing fetal maturity. Values above 15 mg/100 ml rule out term pregnancies and those below 5 mg/100 ml, prematurity.

Urease bound to chitin with glutaraldehyde.

The enzyme urease (urea amidohydrolase, EC 3.5.1.5) prepared from Cajanus indicus, has been immobilized with glutaraldehyde-treated chitin as the solid support. The immobilized enzyme was characterized by determining the pH profiles and optimum temperature. Effect of glutaraldehyde concentration on the binding of enzyme to chitin was studied. The storage stability of the chitin-urease system was determined.

Effect of oral contraceptive agents on vitamin nutrition status.

Effects of low estrogen combination type oral contraceptives on some of the biochemical parameters used for assessing vitamin nutritional status were investigated in a group of women who had used the pill for 6 to 12 months. Another group of women was examined initially and then at one or more points of time within the first 6 months of treatment. Following changes were observed in women treated with oral contraceptives: 1) increased excretion of kynurenic acid and xanthurenic acid following tryptophan load; 2) increased EGOT activity and also an increase in vitro stimulation of EGOT with added PALP; 3) increased plasma vitamin A levels; 4) fall in erythrocyte folate levels; 5) fall in erythrocyte transketolase activity with no change in vitro stimulation with TPP; and 6) fall in erythrocyte riboflavin concentration associated with a decrease in erythrocyte glutathione reductase activity and increase in vitro stimulation with FAD. Most of these changes were observed during the first few cycles of oral contraceptive treatment.

Effect of folic acid supplement on birth weights of infants.

Earlier observations from this Institute have indicated that the infants born to mothers receiving folic acid supplements in addition to iron during pregnancy were heavier than those born to mothers receiving iron alone. Since birth weights are influenced by maternal factors like height and parity, a trial was carried on in matched controls with iron and iron and folic acid during the last 12 to 16 weeks of pregnancy. Simultaneously, placental function was also assessed. The effect of the folic acid supplements was more marked on first born children. Incidence of small-for-dates births was half in the iron and folate-supplemented group as compared with the iron-supplemented group. The heights of mothers did not make any difference on the effect of folate supplement. The improvement in the birth weights seem to have been brought about by increase in placental size, cell number, and protein content in the folate supplement group. In view of multivariant deficiency and practical problems in implementing food supplement programs to expectant mothers, supplements of folate and iron to expectant mothers in large scale may bring about an improvement in the incidence of pregnancy anemia and also reduce the infant morbidity and mortality rate due to the high incidence of low-birth weight babies.

PIP: Earlier observations from this Institute have indicated that those infants born to mothers receiving folic acid supplements in addition to iron during pregnancy were heavier than those born to mothers receiving iron alone. Since birthweights are influenced by maternal factors like height and parity, a trial was carried on in matched controls with iron and iron and folic acid during the last 12-16 weeks of pregnancy. Simultaneously, placental function was also assessed. The effect of the folic acid supplements was more marked on 1st-born children. Incidence of small-for-date births was 1/2 in the iron and folate-supplemented group as compared with the iron-supplemented group. The heights of mothers did not make any difference on the effect of folate supplement. The improvement in the birthweights seems to have been brought about by increase in placental size, cell number, and protein content in the folate supplement group. In view of multivariate deficiency and practical problems in implementing food supplement programs to pregnant mothers, supplements of folate acid and iron to expectant mothers in large scale may bring about an improvement in the incidence of pregnancy anemia and also reduce the infant morbidity and mortality rates due to the high incidence of low birthweight babies.

Effect of maternal malnutrition on the bone density of the neonates.

Bone density measurements were made in 15 paried mothers and neonates of well-to-do group and in 21 age and parity matched mothers and their neonates of the poor socioeconomic community using radiodensitometry. Radiodensities of all bones studied in the mothers and neonates of high income group were significantly higher than those of corresponding bones of the mothers and neonates of poor community. This may be a reflection of maternal malnutrition on the intrauterine development of the bone. A close correlation was observed between the bone density of mothers and neonates in the poor income group. Bone density had no relation with birth weight.

Folic acid absorption in pregnancy.

Folic acid absorption was studied in six non-pregnant women, and nine pregnant women undergoing therapeutic termination of pregnancy between 10 to 26 weeks, using 2 mg. of folic acid labelled with 10 muCi of tritiated folic acid. Absorption varied between 65 and 95 per cent, with a mean absorption of 80 per cent, in both pregnant and non-pregnant subjects. Similarly, there was no difference of retention between the groups. The results indicate that there is no change in the absorption of folic acid in the first 26 to 28 weeks of pregnancy.