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Biomedical subjects

R Singh

Publications and source records attributed to R Singh.

At least 145 records · Page 8Linked to original sources
PubMed2001

Acetyl-L-carnitine enhances Na(+), K(+)-ATPase glutathione-S-transferase and multiple unit activity and reduces lipid peroxidation and lipofuscin concentration in aged rat brain regions.

This study investigated the effects of chronically administered acetyl-L-carnitine (ALC) on sodium potassium adenosine triphosphatase (Na(+), K(+)-ATPase), glutathione-S-transferase (GST), glutathione peroxidase (GPx), multiple unit activity (MUA) and lipid peroxidation (LP) and lipofuscin (LF) concentration in brain regions: cerebral cortex, hippocampus, striatum and thalamus, of 24-month-old rats. The activity of Na(+), K(+)-ATPase and GST was enhanced; that of GPx was unaffected. The MUA was increased while the levels of LP and LF were decreased. These novel data provide new additional evidence concerning the antiaging attributes of ALC.

Acetylcarnitine↗
PubMed2001

Nitric oxide-induced cytostasis and cell cycle arrest of a human breast cancer cell line (MDA-MB-231): potential role of cyclin D1.

DETA-NONOate, a nitric oxide (NO) donor, induced cytostasis in the human breast cancer cells MDA-MB-231, and the cells were arrested in the G(1) phase of the cell cycle. This cytostatic effect of the NO donor was associated with the down-regulation of cyclin D1 and hypophosphorylation of the retinoblastoma protein. No changes in the levels of cyclin E or the catalytic partners of these cyclins, CDK2, CDK4, or CDK6, were observed. This NO-induced cytostasis and decrease in cyclin D1 was reversible for up to 48 h of DETA-NONOate (1 mM) treatment. DETA-NONOate (1 mM) produced a steady-state concentration of 0.5 microM of NO over a 24-h period. Synchronized population of the cells exposed to DETA-NONOate remained arrested at the G(1) phase of the cell cycle whereas untreated control cells progressed through the cell cycle after serum stimulation. The cells arrested at the G(1) phase after exposure to the NO donor had low cyclin D1 levels compared with the control cells. The levels of cyclin E and CDK4, however, were similar to the control cells. The decline in cyclin D1 protein preceded the decrease of its mRNA. This decline of cyclin D1 was due to a decrease in its synthesis induced by the NO donor and not due to an increase in its degradation. We conclude that down-regulation of cyclin D1 protein by DETA-NONOate played an important role in the cytostasis and arrest of these tumor cells in the G(1) phase of the cell cycle.

Breast Neoplasms↗
PubMed2001

Neuronal sodium-channel alpha1-subunit mutations in generalized epilepsy with febrile seizures plus.

Generalized epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome characterized by the presence of febrile and afebrile seizures. The first gene, GEFS1, was mapped to chromosome 19q and was identified as the sodium-channel beta1-subunit, SCN1B. A second locus on chromosome 2q, GEFS2, was recently identified as the sodium-channel alpha1-subunit, SCN1A. Single-stranded conformation analysis (SSCA) of SCN1A was performed in 53 unrelated index cases to estimate the frequency of mutations in patients with GEFS+. No mutations were found in 17 isolated cases of GEFS+. Three novel SCN1A mutations-D188V, V1353L, and I1656M-were found in 36 familial cases; of the remaining 33 families, 3 had mutations in SCN1B. On the basis of SSCA, the combined frequency of SCN1A and SCN1B mutations in familial cases of GEFS+ was found to be 17%.

Amino Acid Sequence↗
PubMed2001

Pineal modulation of thymus and immune function in a seasonally breeding tropical rodent, Funambulus pennanti.

The immune system driven by cytokines is now known to be influenced by various other endocrine glands and its hormones. Results of the present study indicate a bidirectional relation between the pineal-thymus axis and the immune system status of an Indian tropical rodent, Funambulus pennanti, during winter months (reproductive inactive phase), when it faces maximum challenges from nature. Pinealectomy during the reproductive inactive phase inhibited thymus and spleen functions, which resulted in significant changes in leukocyte and lymphocyte counts and T-cell-mediated immune function (measured in terms of delayed-type hypersensitivity response to oxazolone). Blastogenic responses of lymphoid cells (thymocytes, splenocytes, and lymph node cells) also decreased following ablation of the pineal gland. To check the definite role of the pineal gland we injected melatonin into pinealectomized squirrels, and the suppressed immune function was significantly restored. Neuroendocrine control of the pineal gland on the histocompatible tissues in this seasonal breeder, F. pennanti, suggests an adaptive mechanism of the immune system for survival in the tropical zone. J. Exp. Zool. 289:90-98, 2001.

Animals↗
PubMed2001

The association between daily mortality and ambient air particle pollution in Montreal, Quebec. 1. Nonaccidental mortality.

This study was undertaken to determine whether variations in concentrations of particles in the ambient air of Montreal, Quebec, during the period 1984 to 1993, were associated with daily variations in nonaccidental mortality. Fixed-site air pollution monitors in Montreal provided daily mean levels of various measures of particulates and gaseous pollutants. Total sulfates were also measured daily (1986-1993) at a monitoring station 150 km southeast of the city (Sutton, Quebec). We estimated associations for PM(2.5), PM(10), total suspended particles, coefficient of haze (COH), extinction coefficient, and sulfates. We used coefficient of haze, extinction coefficient, and Sutton sulfates to predict fine particles and sulfates for days that were missing. To estimate the associations between nonaccidental mortality and ambient air particles, we regressed the logarithm of daily counts of nonaccidental mortality on the daily mean levels for the above measures of particulates, after accounting for seasonal and subseasonal fluctuations in the mortality time series, non-Poisson dispersion, weather variables, and gaseous pollutants. There were 140,939 residents of Montreal who died during the study period. We found evidence of associations between daily nonaccidental deaths and most measures of particulate air pollution. For example, the mean percentage increase (MPC) for an increase of total suspended particles of 28.57 microg/m(3) (interquartile range, IQ), evaluated at lag 0 days, was 1.86% (95% confidence interval (CI): 0.00-3.76%), and for an increase of coefficient of haze (IQ=18.5 COH units per 327.8 linear m) the MPC was 1.44% (95% CI: 0.75-2.14%). These results are similar to findings from other studies (the mean percentage increase in nonaccidental deaths for a 100 microg/m(3) increase in daily total suspended particles was 6.7%). We also found increases for fine particles and for inhalable particles, but the confidence intervals included unity. All measures of sulfates showed increased daily mortality; e.g., the MPC for sulfates from fine particles (IQ=3.51 microg/m(3)) was 1.86% (95% CI: 0.40-3.35%). We generally found higher excesses in daily mortality for persons 65 years of age and for exposures averaged across lags 0, 1, and 2 days. The slope of the association between daily mortality and ambient air particles in Montreal, which has lower levels of pollution than most major urban centers, is similar to that reported in most other industrialized cities. This study therefore provides further evidence that the association is linear and that any threshold effect, should it exist, would be found at lower levels of air pollution than those found in Montreal.

Aged↗
PubMed2001

The association between daily mortality and ambient air particle pollution in Montreal, Quebec. 2. Cause-specific mortality.

This study was undertaken to determine whether variations in concentrations of particulates in the ambient air of Montreal, Quebec, during the period 1984 to 1993, were associated with daily variations in cause-specific daily mortality. Fixed-site air pollution monitors in Montreal provided daily mean levels of various measures of particles and gaseous pollutants. Total sulfate was also measured daily (1986-1993) at a monitoring station 150 km southeast of the city (Sutton, Quebec). We used coefficient of haze (COH), extinction coefficient, and sulfate from the Sutton station to predict fine particles and sulfate from fine particles for days that were missing. We estimated associations between cause-specific mortality and PM(2.5), PM(10), predicted fine particles and fine sulfate particles, total suspended particles, coefficient of haze, extinction coefficient, and total sulfate measured at the Sutton station. We selected a set of underlying causes of death, as recorded on the death certificates, as the endpoint and then regressed the logarithm of daily counts of cause-specific mortality on the daily mean levels for the above measures of particulates, after accounting for seasonal and subseasonal fluctuations in the mortality time series, non-Poisson dispersion, weather variables, and gaseous pollutants. We found positive and statistically significant associations between the daily measures of ambient particle mass and sulfate mass and the deaths from respiratory diseases and diabetes. The mean percentage change in daily mortality (MPC), evaluated at the interquartile range for pollutants averaged over the day of death and the preceding 2 days, for deaths from respiratory diseases was MPC(COH)=6.90% (95% CI: 3.69-10.21%), MPC(Predicted PM2.5)= 9.03% (95% CI: 5.83- 12.33%), and MPC(Sutton sulfate)=4.64% (95% CI: 2.46-6.86%). For diabetes, the corresponding estimates were MPC(COH)=7.50% (95% CI: 1.96-13.34%), MPC(Predicted PM2.5)=7.59% (95% CI: 2.36-13.09%), and MPC(Sutton sulfate)=4.48% (95% CI: 1.08-7.99%). Among individuals older than 65 years at time of death, we found consistent associations across our metrics of particles for neoplasms and coronary artery diseases. Associations with sulfate mass were also found among elderly persons who died of cardiovascular diseases and of lung cancer. These associations were consistent with linear relationships. The associations found for respiratory diseases and for cardiovascular diseases, especially in the elderly, are in line with some of the current hypotheses regarding mechanisms by which ambient particles may increase daily mortality. The positive associations found for cancer and for diabetes may be understood through a general hypothesis proposed by Frank and Tankersley, who suggested that persons in failing health may be at higher risk for external insults through the failure of regulating physiological set points. The association with diabetes may be interpreted in light of recent toxicological findings that inhalation of urban particles in animals increases blood pressure and plasmatic levels of endothelins that enhance vasoconstriction and alter electrophysiology. Further research to confirm these findings and to determine whether they are causal is warranted.

Aged↗
PubMed2001

Nitric oxide activates the sarcolemmal K(ATP) channel in normoxic and chronically hypoxic hearts by a cyclic GMP-dependent mechanism.

Chronic myocardial hypoxia results in elevated nitric oxide (NO) production and increased current through the sarcolemmal K(ATP) channel. We hypothesized these two processes are related and determined whether NO alters the electrophysiology of Purkinje fibers obtained from rabbits (n=12/group) raised in a normoxic (F(I)O2=0.21) or hypoxic (F(I)O2=0.12) environment from birth to 9 days of age. Action potential duration (APD)(90) was shorter (112+/-3 ms v 126+/-3 ms) and maximum diastolic potential (MDP) was more negative (-84+/-2 mV v-80+/-1 mV) in hypoxic hearts compared with normoxic controls. In normoxic hearts the NO donors, S-nitrosoglutathione (GSNO) 50 microM and spermine NONOate (50 microM) shortened APD(90) and increased MDP to levels present in chronically hypoxic hearts. This effect was completely abolished by the K(ATP) channel blocker glibenclamide (3 microM) and by a nitric oxide trap, Carboxy-PTIO (100 microM). The NO carrier glutathione (50 microM) and decomposed spermine NONOate had no effect on APD(90) or MDP. GSNO had no effect in hypoxic hearts; however, when GSNO was combined with glibenclamide APD(90) increased, and MDP decreased to normoxic values. 8-Bromo cGMP (100 microM) shortened APD(90) and increased MDP to levels present in chronically hypoxic hearts. This effect was abolished by glibenclamide. A soluble guanylyl cyclase inhibitor, ODQ (10 microM), had no effect on action potentials in normoxic hearts but in hypoxic hearts resulted in an increase in APD(90) to levels present in normoxic hearts and a decrease in MDP. The effect of ODQ could not be reversed by GSNO. We conclude that NO activates the sarcolemmal K(ATP) channel in normoxic and chronically hypoxic hearts by a cyclic GMP-dependent mechanism.

Action Potentials↗
PubMed2001

Evaluation of diagnostic efficiency of computerized image analysis based quantitative nuclear parameters in papillary and follicular thyroid tumors using paraffin-embedded tissue sections.

Computerized image analysis (IA) system has emerged in recent years as a very powerful tool for objective and reproducible quantification of histological features. It has shown considerable potential for diagnostic application in diverse histological situations. The objectives of the present study were to evaluate the discriminatory diagnostic efficiency of computerized image analysis based quantitative subvisual nuclear parameters in papillary and follicular neoplasms of thyroid. A total of 60 cases were studied. Forty-four cases belonged to training set and 16 cases belonged to a test set. A minimum of 100 nuclei was analyzed in each case using uniform 5 m mm thick hematoxylin stained sections. The IA workstation comprised of an Olympus microscope, a 10 bit digital video camera, an image grabber card and a pentium 120 MHz computer. Optimas 5.2 software was utilized for data collection on 8 morphometric and 8 densitometric parameters. Multivariate stepwise discriminant statistical analysis of data was done with the help of BMDP statistical software release 7.0. Results from a training set revealed correct classification rates of 98.0%, 84.5% and 61.2% for the histological groups of hyperplastic papillae versus papillae of papillary carcinoma (group I), follicular variant of papillary carcinoma versus the broad category of follicular neoplasms consisting of both follicular adenoma and follicular carcinoma (group II) and follicular adenoma versus follicular carcinoma (group III), respectively. Results of test set revealed correct classification rates of 100%, 80% and 50% for groups I, II and III respectively. It was concluded that computerized nuclear IA parameters have potential usefulness for discriminating benign versus malignant papillary lesions of thyroid, follicular variant of papillary carcinoma versus follicular adenoma and/or follicular carcinoma but are of no value in discriminating between follicular adenoma and follicular carcinoma.

Adenocarcinoma, Follicular↗
PubMed2001

Advanced glycation end-products: a review.

Advanced glycation end-products are a complex and heterogeneous group of compounds that have been implicated in diabetes related complications. At present it is not known if they are the cause or the consequence of the complications observed. We discuss the chemistry of advanced glycated end-product formation and their patho-biochemistry particularly in relation to the diabetic microvascular complications of retinopathy, neuropathy and nephropathy as well as their role in the accelerated vasculopathy observed in diabetes. The concept of carbonyl stress as a cause for advanced glycated end-product toxicity is mentioned. We discuss alterations in the concentrations of advanced glycated end-products in the body, particularly in relation to changes occurring with age, diabetes and its complications such as nephropathy. Problems relating to current methods of advanced glycated end-product detection and measurement are highlighted including the lack of a universally established method of detection or unit of measurement. Agents used for the treatment of advanced glycated end-product accumulation are reviewed, with an emphasis on the results of the recent phase III trials using aminoguanidine and diabetes related complications.

Aging↗
PubMed2001

Correlation between omeprazole hydroxylase and CYP2C19 genotype in North Indians.

OBJECTIVE: To comprehend the correlation between the in vitro activity of hepatic omeprazole (OMZ) hydroxylase and genotype of North Indians with respect to CYP2C19. METHODS: Microsomes were prepared from the livers of 15 North Indians. Assay of OMZ hydroxylase was performed by incubating the microsomes with OMZ in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH). The 5-OH-OMZ formed was assayed using high-performance liquid chromatography. Genomic DNA isolated from the blood of the same individuals was employed for genotyping of CYP2C19*2 and *3 using polymerase chain reaction-based diagnostic tests. RESULTS: Thirteen subjects demonstrated an average OMZ hydroxylase activity of 138 pmol 5-OH-OMZ formed/min/mg protein. They were designated as extensive metabolisers (EMs). Eight EMs were homozygous with CYP2C19*1/*1 genotype and demonstrated the highest average activity of OMZ hydroxylase (169 pmol 5-OH-OMZ formed/min/mg protein). Five heterozygous EMs (CYP2C19*1/*2) demonstrated 52% activity of OMZ hydroxylase compared with eight homozygous EMs (CYP2CI9*1/*1). Two subjects demonstrated 11% activity of OMZ hydroxylase (15 pmol 5-OH-OMZ formed/min/mg protein) compared with EMs. Hence, these individuals were designated as poor metabolisers (PMs). Both PMs had genotype CYP2C19*2/*2. None of the subjects had CYP2C19*3/*3 genotype. CONCLUSION: The results of the present study demonstrated concordance between the in vitro activity of OMZ hydroxylase and the CYP2C19 genotype in North Indians.

Alleles↗
PubMed2001

Purification and characterization of dihydroxyacetone phosphate reductase from immature seeds of Brassica campestris L.

Dihydroxyacetone phosphate reductase (DHAP reductase) was purified to apparent electrophoretic homogeneity with about 24% recovery from immature seeds of Brassica campestris using (NH(4))(2)SO(4) fractionation, affinity chromatography, gel filtration and adsorption chromatography. The purified enzyme with molecular mass of about 62 kDa was a dimer with subunit molecular mass of 32 kDa. The enzyme exhibited maximum activity at pH 7.5 and was highly specific for NADH and DHAP. Typical Michaelis-Menten kinetics was obtained for both the substrates with K(m) values of 3.3 and 26.6 &mgr;M for NADH and DHAP, respectively. The enzyme did not require any metal ion for its activity. Rather, the activity was inhibited by Na(+), K(+), Mn(2+), Mg(2+,) and Ca(2+). ATP and fructose-1,6-P(2) inhibited the enzyme non-competitively with respect to DHAP with K(i) values of 0.96 and 1.3 mM, respectively. Substrate interaction kinetics and product inhibition studies were consistent with compulsory-ordered bi-bi reaction mechanism with NADH being the first substrate to bind and NAD being the last product to dissociate. Based on the properties discussed here, it appears that the enzyme probably functions for the production of glycerol-3-P from DHAP.

Journal Article↗
PubMed2001

Effect of in-the-bag intraocular lens fixation on the prevention of posterior capsule opacification.

PURPOSE: To compare the incidence of posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) and phacoemulsification and to evaluate the role of posterior chamber intraocular lens (PC IOL) haptic fixation and biomaterial/design in reducing the incidence. SETTING: Postgraduate Institute of Medical Education and Research, Chandigarh, India; Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: This study comprised 278 eyes of 263 patients having ECCE and 318 eyes of 297 patients having phacoemulsification with PC IOL implantation. Posterior capsule opacification leading to a decrease in Snellen visual acuity of 2 or more lines was considered visually significant. The presence of PCO and IOL haptic fixation were evaluated postoperatively using slitlamp biomicroscopy. Haptic position was noted as in-the-bag (B-B), 1 haptic in the bag and 1 in the sulcus (bag-sulcus [B-S]), or both haptics out of the bag (sulcus-sulcus [S-S]). In addition, the rate of visually significant PCO was compared among 3 IOL biomaterials: poly(methyl methacrylate), silicone, and hydrophobic acrylic. RESULTS: Visually significant PCO occurred in 42.45% of eyes having ECCE and 19.18% of eyes having phacoemulsification (P <.001, chi-square test) after a mean follow-up of 2.4 years +/- 0.7 (SD). In both groups, visually significant PCO was significantly less in eyes with B-B fixation than in those with B-S or S-S fixation (P <.001). The rate of visually significant PCO in all eyes in the phacoemulsification group with B-B fixation was low (11.90%) and was significantly lower in eyes with a hydrophobic acrylic IOL (2.22%; P <.05, chi-square test). CONCLUSIONS: In-the-bag PC IOL fixation is required to consistently reduce the incidence of PCO. Thorough removal of lens substance, including hydrodissection-assisted cortical cleanup, and in-the-bag PC IOL fixation seem to be the most important factors in reducing PCO, regardless of surgical procedure or IOL type used. Intraocular lens biomaterial and design also help prevent PCO.

Biocompatible Materials↗
PubMed2001

Necessity of vitrectomy when optic capture is performed in children older than 5 years.

PURPOSE: To determine whether anterior vitrectomy is necessary when optic capture is performed in children between 5 and 12 years old with congenital cataract. SETTING: Iladevi Cataract and IOL Research Center, Ahmedabad, India. METHODS: This prospective randomized controlled study comprised 41 eyes of 25 children whose mean age was 83.57 months (range 60 to 144 months). Intraocular lens (IOL) implantation with optic capture through a primary posterior continuous curvilinear capsulorhexis was performed in all the eyes. The IOL haptics were bag fixated. Patients were randomly assigned to 1 of 2 groups. Vitrectomy was performed in 1 group (n = 21 eyes) and not performed in the other group (n = 20 eyes). The mean follow-up was 21.04 months. A Student t test and chi-square test were used for statistical analysis. RESULTS: All eyes in the vitrectomy group and 30% in the no-vitrectomy group had a clear visual axis at the last follow-up (P <.001) The visual axis was obscured as a result of anterior vitreous fibrosis in 70% of eyes in the no-vitrectomy group. High-contrast visual acuity was not significantly different between groups (P =.28). Low-contrast sensitivity was significantly better in the vitrectomy group (P =.02). Eighteen eyes (85.7%) in the vitrectomy group and 16 eyes (80%) in the no-vitrectomy group developed deposits on the IOL (P =.62). The deposits were present at the last follow-up in 4 eyes (19.0%) in the vitrectomy group and in 6 eyes (30.0%) in the no-vitrectomy group (P =.85). Three eyes (14.3%) in the vitrectomy group and 8 eyes (40.0%) in the no-vitrectomy group developed synechias (P =.06). CONCLUSION: The results suggest that anterior vitrectomy is necessary with optic capture in children with congenital cataract who are between 5 and 12 years old.

Capsulorhexis↗
PubMed2001

Phacoemulsification of brunescent and black cataracts.

PURPOSE: To evaluate the efficacy and safety of a step-by-step, chop in situ, lateral separation technique to remove brunescent and black cataracts. SETTING: Iladevi Cataract and IOL Research Center, Ahmedabad, India. METHODS: In this prospective study conducted between May 1997 and June 1998, 167 consecutive eyes were divided into 2 groups: Group 1, brunescent cataract (n = 123), and Group 2, black cataract (n = 44). Preoperative assessment included axial length (AL), slitlamp examination, corneal pachymetry, tonometry, and specular microscopy. During phacoemulsification performed by a single surgeon, a step-by-step, chop in situ, lateral separation technique was used to divide the nucleus. Intraoperatively, hydroxypropyl methylcellulose 2% was used and irrigation was by balanced salt solution (BSS). Postoperatively, all eyes were assessed at 1, 7, 30, 90, 180, and 360 days. The results were evaluated using regression analysis, the chi-square test, and the Student t test. RESULTS: The mean follow-up was 14.4 months (range 6 to 35 months) in Group 1 and 13.0 months (range 6 to 32 months) in Group 2. The AL was significantly greater in Group 2 (P =.02). Corticapsular adhesions were present in 17.82% in Group 1 and 31.82% in Group 2. The mean cumulative dissipated energy was 2.03 and 3.12, respectively (P =.0005). Wound site thermal injury occurred in 16 eyes (13.01%) in Group 1 and 4 eyes (9.09%) in Group 2. No serious intraoperative or postoperative complications were noted. One day postoperatively, the mean rise in intraocular pressure was 1.76 mm Hg in Group 1 and 4.15 mm Hg in Group 2 (P =.012), and transient corneal edema was present in 24.40% and 34.10%, respectively. At 1 month, the endothelial cell loss was 10.06% in Group 1 and 9.22% in Group 2. CONCLUSION: The step-by-step, chop in situ, lateral separation technique was effective and did not produce serious complications such as zonulysis or posterior capsule rupture. However, the incidence of wound site thermal injury and endothelial cell loss was greater than after emulsification of standard cataracts.

Acetates↗
PubMed2001

Effect of nutrients supplementation on anaerobic sludge development and activity for treating distillery effluent.

Startup of laboratory anaerobic reactors and treatment efficiency were investigated by supplementing the distillery effluent feed with macronutrients (Ca, P) and micronutrients (Ni, Fe and Co) under mesophilic conditions. Calcium and phosphate were deterimental to the treatment efficiency and sludge granulation. Traces of salts of iron, nickel and cobalt, individually and in combinations improved the COD removal efficiency and sludge granulation process.

Alcohols↗
PubMed2001

Monitoring of Ganga water and sediments vis-à-vis tannery pollution at Kanpur (India): a case study.

The leather industry, besides being a major contributor to the Indian national economy, is unfortunately also one of the major polluters. The present article discusses the influence of the wastes on the physicochemical characteristics of the Ganga water and sediments. Two sampling sites have been chosen at Kanpur, the first before and the second after the point where tanneries are located. The same physicochemical parameters which have been determined in the wastes have been monitored at these two sites for two seasons. The results reveal that most parameters increase as the river traverses between these two points. The increase in values of parameters such as BOD, COD, Cl-, and total solids could be due to the domestic wastes just as much as to the tannery wastes. Phenols and sulfides, can also come from other sources, but their probability of coming from tanneries is higher. However, chromium is one parameter which can primarily be identified to originate from the tanneries. The speciation of the sediments for chromium reveals that the leakage of chromium into the Ganga is taking place at the second site. There is almost a ten fold increase in chromium at the second site as compared to the first. At the first site the surface chromium is primarily in the residual fraction while at the second site it is in the Fe-Mn oxide fractions.

Chromium↗