Sudhir K. Goel

Groundwater Contaminated with Hexavalent Chromium [Cr (VI)]: A Health Survey and Clinical Examination of Community Inhabitants (Kanpur, India)

Background We assessed the health effects of hexavalent chromium groundwater contamination (from tanneries and chrome sulfate manufacturing) in Kanpur, India. Methods The health status of residents living in areas with high Cr (VI) groundwater contamination (N = 186) were compared to residents with similar social and demographic features living in communities having no elevated Cr (VI) levels (N = 230). Subjects were recruited at health camps in both the areas. Health status was evaluated with health questionnaires, spirometry and blood hematology measures. Cr (VI) was measured in groundwater samples by diphenylcarbazide reagent method. Results Residents from communities with known Cr (VI) contamination had more self-reports of digestive and dermatological disorders and hematological abnormalities. GI distress was reported in 39.2% vs. 17.2% males (AOR = 3.1) and 39.3% vs. 21% females (AOR = 2.44); skin abnormalities in 24.5% vs. 9.2% males (AOR = 3.48) and 25% vs. 4.9% females (AOR = 6.57). Residents from affected communities had greater RBCs (among 30.7% males and 46.1% females), lower MCVs (among 62.8% males) and less platelets (among 68% males and 72% females) than matched controls. There were no differences in leucocytes count and spirometry parameters. Conclusions Living in communities with Cr (VI) groundwater is associated with gastrointestinal and dermatological complaints and abnormal hematological function. Limitations of this study include small sample size and the lack of long term follow-up.

GSTM1, GSTT1, and GSTP1 polymorphism in north Indian population and its influence on the hydroquinone-induced in vitro genotoxicity.

Glutathione S transferase (GST) gene polymorphism examined among north Indians and correlated with hydroquinone (HQ) genotoxicity to help in clinical prediction of susceptibility of HQ toxicity. Lymphocytes of individuals with/without GSTM1, GSTT1, and GSTP1 (ile/ile or val/val) were exposed to HQ (20, 40, or 80 μM) and examined chromosomal aberrations (CA) or cytokinesis-block micronucleus assays. Among north Indians the frequencies of GSTM1 (null), GSTT1 (null), and both null were found to be 41.1, 21.9, and 12.7%, whereas frequencies of GSTP1 with (ile/ile) or (ile/val), or (val/val) were 52, 42.1, or 5.9%, respectively. Individuals with null GSTM1, GSTT1, and GSTP1 (val/val) showed inhibition of mitotic index (MI) and significant (p < 0.01) induction of CA as compared to individuals with GSTM1, GSTT1, and GSTP1 (ile/ile). Micronucleus formation was found to be significant (p < 0.05 or 0.01) in both the genotypes. Results indicate that GSTM1, GSTT1 (null), and GSTP1 (val/val) are sensitive to HQ genotoxicity.

Expression of estrogen receptor co-regulators SRC-1, RIP140 and NCoR and their interaction with estrogen receptor in rat uterus, under the influence of ormeloxifene

Ormeloxifene binds competitively to ERs and antagonizes estrogen-induced gene expression in the uterus. However its detailed molecular mechanisms are not well understood. Present study was aimed to examine the changes in expression pattern of co-regulatory proteins SRC-1 (co-activator), RIP140 and NCoR (co-repressors) and their interaction with ERalpha in rat uterus under the influence of ormeloxifene (Orm) and tamoxifen (Tam). Adult ovariectomized rats were treated with estradiol (E(2)) (5 microg/100g), or Orm or Tam (200 microg/100g, s.c.) alone or along with E(2), for 3 days. RT-PCR analysis of uterine RNA and immunoblotting of uterine extracts revealed that expression of SRC-1, RIP140 and NCoR was insensitive to E(2) or Orm or Tam treatment. Direct protein-protein interaction experiments using co-immunoprecipitation revealed that E(2)-induced the interaction of ERalpha with co-activator SRC-1. In rats given Orm alone or along with E(2), there was a significant reduction in E(2)-induced effect on ERalpha-SRC-1 interaction. In case of ERbeta and SRC-1, Orm reduced interaction only in the absence of E(2). Interaction of RIP140 or NCoR with ERalpha was found to be more in rats treated with Orm along with E(2) as compared to that in E(2)-treated rats whereas no such recruitment was found in Tam treated rats. Interaction of RIP140 with ERbeta was insensitive to Orm or Tam treatment whereas the interaction of NCoR with ERalpha and ERbeta was increased in Orm treated rats. Ormeloxifene also showed inhibitory effects on uterine ER-ERE binding and estrogen-induced expression of progesterone receptor. Taken together, these findings demonstrate that ormeloxifene antagonizes ERalpha-mediated transcription by inhibiting the recruitment of SRC-1 and inducing the recruitment of RIP140 and NCoR.

New Protocol for Detection of Intron 22 Inversion Mutation From Cases With Hemophilia A

Background: Hemophilia A is a X-linked recessive bleeding disorder characterized by qualitative and quantitative deficiency of factor VIII resulting from heterogeneous mutations in the factor VIII gene located in the Xq28 region. Intron 22 inversion (Inv22) mutation is one of the major causes of the protein alteration in factor VIII; its frequency is 40% to 50% in severe patients. Long polymerase chain reaction (PCR) and inverse PCR (I-PCR) have been used for the detection of Inv22 mutation. Objective: Development of new protocol for detection of Inv22 mutation. Method: We have designed a new method for the detection of Inv22 mutation in complementary DNA (cDNA) of patients. Real-time PCR targeting exons 21 to 22, 22 to 23, and 23 to 24 of factor VIII gene were used in cases with hemophilia A. Samples that were inversion positive by this new method were cross-checked by the conventional I-PCR method. We observed that region between exons 22 and 23 could not be amplified, while in negative cases and controls a 480 bp product is obtained. Result: The method was validated in 20 cases with severe hemophilia A by the new cDNA method, and 8 cases were inversion positive, whereas 12 were negative cases. The findings were confirmed by standard I-PCR method. Complete correlation was observed. Conclusion: Conventional long PCR and I-PCR methods are work intensive, prolonged, and sometimes difficult to be standardize. The cDNA method is short, involves 3 short-segment amplifications, and is easy to reproduce.

Influence of trichloroethylene treatment on phosphoinositides in rat brain

The effect of oral administration of trichloroethylene, a neurotoxic solvent, on the levels of phosphoinositides in rat brain was studied. Two hours after administration of a single dose of trichloroethylene (1000 mg/kg body wt.), the levels of phosphatidylinositol (PI) and phosphatidylinositol 4,5-biphosphate (PIP2) were reduced by 24 and 17%, respectively, without any significant change in that of phosphatidylinositol-4-phosphate (PIP). Twenty hours after treatment, the levels of PI and PIP2 were increased by 22 and 38%, respectively. Repeated administration of the same dose of trichloroethylene for 1 year markedly reduced the levels of PI (52%), PIP (23%) and PIP2 (45%). These results for the first time suggest the involvement of a phosphoinositide messenger system in trichloroethylene neurotoxicity.

Toxicity of n-hexane and n-heptane: Some biochemical changes in liver and serum

The toxic effects of i.p. administered n-hexane and n-heptane on biochemical processes in rat liver, as indicated by the increase in alkaline phosphatase activity and decrease in FDP aldolase activity, and their reflection on blood chemistry, were studied. Serum cholinesterase activity and albumin and cholesterol content showed statistically significant decreases with the increase in FDP aldolase activity. The significance of the findings is discussed.

Occupational health hazards of trichloroethylene among workers in relation to altered mRNA expression of cell cycle regulating genes (p53, p21, bax and bcl-2) and PPARA

Trichloroethylene (TCE) is widely used as a metal degreaser in industrial processes. The present study reports on the effects of TCE exposure on workers employed in the lock industries. To ensure exposure of the workers to TCE, its toxic metabolites, trichloroacetic acid (TCA), dichloroacetic acid (DCA) and trichloroethanol (TCEOH) were detected in the plasma of the subjects through solid phase microextraction-gas chromatography-electron capture detection. TCA, DCA and TCEOH were detected in the range of 0.004–2.494 μg/mL, 0.01–3.612 μg/mL and 0.002–0.617 μg/mL, respectively. Quantitative reverse transcription polymerase chain reaction analysis revealed up-regulated expression of p53 (2.4-fold; p < 0.05), p21 (2-fold; p < 0.01), bax (2.9-fold; p < 0.01) mRNAs and down-regulated expression of bcl-2 (67%; p < 0.05) mRNAs, indicating DNA damaging potential of these metabolites. No effects were observed on the levels of p16 and c-myc mRNAs. Further, as TCA and DCA, the ligand of peroxisome proliferator activated receptor alpha (PPARA), are involved in the process of hepatocarcinogenesis in rodents, we examined expression of PPARA mRNA and let-7c miRNA in the workers. No statistically significant differences in expression of PPARA mRNA and let-7c miRNA in patients were observed as compared to values in controls. Dehydroepiandosterone sulfate (DHEAS) is a reported endogenous ligand of PPARA so its competitive role was also studied. We observed decreased levels of DHEAS hormone in the subjects. Hence, its involvement in mediation of the observed changes in the levels of various mRNAs analyzed in this study appears unlikely.

Genetic Predisposition for Dermal Problems in Hexavalent Chromium Exposed Population

We studied the effect of genetic susceptibility on hexavalent chromium induced dermal adversities. The health status of population was examined from the areas of Kanpur (India) having the elevated hexavalent chromium levels in groundwater. Blood samples were collected for DNA isolation to conduct polymorphic determination of genes, namely: NQO1 (C609T), hOGG1 (C1245G), GSTT1, and GSTM1 (deletion). Symptomatic exposed subjects (n = 38) were compared with asymptomatic exposed subjects (n = 108) along with asymptomatic controls (n = 148) from a non contaminated reference community. Exposed symptomatic group consisted of 36.8% subjects who were GSTM1 null genotyped as compared to asymptomatic where only 19.4% subjects were null. The exposed subjects with GSTM1 null genotype were more susceptible to dermal adversities in comparison with wild genotyped subjects (OR = 2.42; 95% CI = 1.071–5.451). Age, smoking, gender or duration of residence were not found to have any confounding effect towards this association. Association with other genes was not statistically significant, nonetheless, possible contribution by these genes cannot be ruled out. In conclusion, variation in the polymorphic status of GSTM1 gene may influence dermal outcomes among residents from Cr(VI) contaminated areas. Further studies are therefore, needed to examine these observations among different population groups.

Study of intron 22 inversion mutation in north India with review.

The present study assessed the frequency of intron 22 inversion mutation (Inv 22) in north Indian population with a cost analysis of different methods used for Inv 22 detection. We assessed the frequency of intron 22 inversion mutation in a series of 181 cases with hemophilia A and also compared methods used for detection of the mutation including the long-distance PCR, Southern blot analysis, and inverse PCR in terms of cost, infrastructure, and technical input as well as turnaround time. The study group comprised 102 severe cases and 79 moderate cases of hemophilia A from a north Indian population of which 77 cases tested positive for Inv 22. The observed frequency of Inv22 mutation was 42.5%. Inv 22 resulted in a more severe phenotype and lower FVIII bioassay levels as compared to Inv 22 negative cases. Inv 22 positive cases also frequently presented with bleeding episodes at birth and the mean age for commencement of bleeding was lower (19 months) as compared to Inv-negative cases (50 months). The mean frequency of Inv 22 in cases with hemophilia A in a worldwide review is 44.25% of hemophilia A. Inv 22 can be conveniently detected by using the inverse PCR method. This technique is easy to standardize and lowest in cost.