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Biomedical subjects

S K Gupta

Publications and source records attributed to S K Gupta.

At least 19 recordsLinked to original sources
PubMed2007

Biodegradation of distillery spent wash in anaerobic hybrid reactor.

A lab-scale anaerobic hybrid (combining sludge blanket and filter) reactor was operated in a continuous mode to study anaerobic biodegradation of distillery-spent wash. The study demonstrated that at optimum hydraulic retention time (HRT), 5 days and organic loading rate (OLR), 8.7kgCOD/m(3)d, the COD removal efficiency of the reactor was 79%. The anaerobic reduction of sulfate increases sulfide concentration, which inhibited the metabolism of methanogens and reduced the performance of the reactors. The kinetics of biomass growth i.e. yield coefficient (Y,0.0532) and decay coefficient (K(d), 0.0041d(-1)) was obtained using Lawrence and McCarty model. However, this model failed in determining the kinetics of substrate utilization. Bhatia et al. model having inbuilt provision of process inhibition described the kinetics of substrate utilization, i.e. maximum rate of substrate utilization (R,1.945d(-1)) and inhibition coefficient values (K(i),0.032L/mg). Modeling of the reactor demonstrated that Parkin and Speece, and Bhatia et al. models, both, could be used to predict the effluent substrate concentration. However, Parkin and Speece model predicts effluent COD more precisely (within +/-2%) than Bhatia et al. model (within +/-5-20%) of the experimental value. Karhadkar et al. model predicted biogas yield within +/-5% of the experimental value.

Bacteria, Anaerobic↗
PubMed2006

Mathematical modeling of leachates from ash ponds of thermal power plants.

The present study describes the development of empirical models for the prediction of various trace metals i.e., Mn, Cu, Fe, Zn and Pb found in the leachates generated from the ash ponds of various thermal power plants. The dispersion phenomenon of these trace metals followed first order reaction rate kinetics. The empirical models for individual trace metals derived from the lab scale models data correlate well with the real field data with regression coefficients varying from 0.93 to 0.98. The predicted concentrations of the trace metals varied within +/-3% of the observed values in the leachates generated from the ash ponds of four thermal power plants with standard deviation varying from 0.001 to 0.032. The empirical models derived from the study can be applied for prediction of trace metals in leachates generated from similar thermal power plants.

Environmental Monitoring↗
PubMed2006

Hematopoietic cells from gadd45a-deficient and gadd45b-deficient mice exhibit impaired stress responses to acute stimulation with cytokines, myeloablation and inflammation.

The gadd45 family of gene(s) is rapidly induced by genotoxic stress or by differentiation-inducing cytokines. Using bone marrow (BM) from gadd45a-/-, gadd45b-/- and wild-type (wt) mice, we investigated their role in stress responses of myeloid cells to acute stimulation with differentiating cytokines, myelotoxic agents and inflammatory substances. Bone marrow cells from gadd45a-/- and gadd45b-/- mice displayed compromised myeloid differentiation and higher apoptosis in vitro, following acute stimulation with a variety of differentiating cytokines. Intriguingly, gadd45a-/- and gadd45b-/- colony forming units granulocyte/macrophage progenitors displayed prolonged proliferation capacity compared to wt controls upon re-plating in methylcellulose supplemented with interleukin-3. The recovery of the BM myeloid compartment following 5-Fluorouracil-induced myelo-ablation was much slower in gadd45a-/- and gadd45b-/- mice compared to wt controls. Furthermore, the response of myeloid cells to inflammatory stress, inflicted via intraperitoneal administration of sodium caseinate was impaired in gadd45a-/- and gadd45b-/- mice compared to age-matched wt mice, as indicated by lower percentage of Gr-1-positive cells in the BM and lower number of myeloid cells in peritoneal exudates. Overall, these data indicate that both gadd45a and gadd45b play a role in modulating physiological stress responses of myeloid cells to acute stimulation with differentiating cytokines, myelo-ablation and inflammation. These findings should aid in understanding the response of normal and malignant hematopoietic cells to physiological and chemical stressors including anticancer agents.

Animals↗
PubMed2006

Anaerobic biogranulation in a hybrid reactor treating phenolic waste.

Granulation was examined in four similar anaerobic hybrid reactors 15.5L volume (with an effective volume of 13.5L) during the treatment of synthetic coal wastewater at the mesophilic temperature of 27+/-5 degrees C. The hybrid reactors are a combination of UASB unit at the lower part and an anaerobic filter at the upper end. Synthetic wastewater with an average chemical oxygen demand (COD) of 2,240 mg/L, phenolics concentration of 752 mg/L and a mixture of volatile fatty acids was fed to three hybrid reactors. The fourth reactor, control system, was fed with a wastewater containing sodium acetate and mineral nutrients. Coal waste water contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3mg/L) as major phenolic compounds. A mixture of anaerobic digester sludge and partially granulated sludge (3:1) were used as seed materials for the start up of the reactors. Granules were observed after 45 days of operation of the systems. The granules ranged from 0.4 to 1.2 mm in diameter with good settling characteristics with an SVI of 12 mL/gSS. After granulation, the hybrid reactor performed steadily with phenolics and COD removal efficiencies of 93% and 88%, respectively at volumetric loading rate of 2.24 g COD/Ld and hydraulic retention time of 24 h. The removal efficiencies for phenol and m/p-cresols reached 92% and 93% (corresponding to 450.8 and 153 mg/L), while o-cresol was degraded to 88% (corresponding to 51.04 mg/L). Dimethyl phenols could be removed completely at all the organic loadings and did not contribute much to the residual organics. Biodegradation of o-cresol was obtained in the hybrid-UASB reactors.

Anaerobiosis↗
PubMed2006

Assessing the efficiency of extracorporeal shockwave lithotripsy for stones in renal units with impaired function: a prospective controlled study.

The objective was to determine the efficiency of extracorporeal shockwave lithotripsy (ESWL) in clearing stones from renal units with impaired function. Thirty-five patients with poorly functioning kidneys determined by intravenous urogram and 99mtechnetium diethylene triamine pentacetic acid renal dynamic scan underwent ESWL. Stone clearance was assessed at 3 months and compared with that in normally functioning kidneys. The study group was divided into two subgroups. Those with split glomerular filtration rate (GFR) of the concerned kidney between 10 and 20 ml/min were in group 1. Group 2 consisted of patients with split GFR between 20 and 30 ml/min. A control group (group 3) was formed from patients with urolithiasis and normally functioning kidneys. The overall retreatment rate was 84.4%. The overall stone clearance rate in the study group was 34.2% while it was 57.7% in the control group. The stone clearance rate in group 2 was 40%. The difference in stone clearance rate between the study and control groups was statistically significant (P=0.023) but that between group 2 and the control group was not (P=0.159). The incidence of steinstrasse between the study group 2 and control group was not statistically significant (P=0.408). The clearance rate for ureteral stones was comparable in all the three groups. The stone-free rate and rate of steinstrasse for renal stones in kidneys with moderately impaired function were comparable to normally functioning kidneys. However, kidneys with severely impaired function had poor results. The clearance rate for ureteral stones was not influenced by the impairment of renal function.

Adult↗
PubMed2006

Factors influencing synonymous codon and amino acid usage biases in Mimivirus.

Synonymous codon and amino acid usage biases have been investigated in 903 Mimivirus protein-coding genes in order to understand the architecture and evolution of Mimivirus genome. As expected for an AT-rich genome, third codon positions of the synonymous codons of Mimivirus carry mostly A or T bases. It was found that codon usage bias in Mimivirus genes is dictated both by mutational pressure and translational selection. Evidences show that four factors such as mean molecular weight (MMW), hydropathy, aromaticity and cysteine content are mostly responsible for the variation of amino acid usage in Mimivirus proteins. Based on our observation, we suggest that genes involved in translation, DNA repair, protein folding, etc., have been laterally transferred to Mimivirus a long ago from living organism and with time these genes acquire the codon usage pattern of other Mimivirus genes under selection pressure.

Amino Acids↗
PubMed2006

Removal of chlorophenols in sequential anaerobic-aerobic reactors.

Combination of upflow anaerobic sludge blanket (UASB) and aerobic rotating biological contactor (RBC) reactors having higher biomass concentration and higher sludge retention time (SRT) was applied for the sequential treatment of priority pollutant chlorophenol containing wastewater. Target compounds 2-chlorophenol (2-CP) and 2,4-dichlorophenol (2,4-DCP) present in two simulated wastewaters at a concentration of 30 mg/l each individually were sequentially treated in continuous mode by combined UASB-I, RBC-I and combined UASB-II, RBC-II reactors, respectively after the acclimation of their biomass with the corresponding chlorophenol. Reactor combinations took 190 and 215 days for acclimation with 30 mg/l of 2-CP and 2,4-DCP respectively. Hydraulic retention time (HRT) studies showed that 12h HRT of UASB-I and 23 h HRT of RBC-I as well as 12h HRT of UASB-II and 28.8h HRT of RBC-II were the optimum combinations for the treatment of simulated wastewater containing 2-CP and 2,4-DCP respectively. Optimum HRT combinations produced 2-CP and 2,4-DCP effluent having corresponding chlorophenol concentration of below detectable limit (BDL) and 0.1 mg/l respectively. Half velocity coefficients (Ks) for 2-CP and 2,4-DCP biodegradation in UASB reactors were determined to be 5.07 mg 2-CP/l and 6.49 mg 2,4-DCP/l. Optimum ratio of substrate (chlorophenol): co-substrate (sodium acetate) was 1:100.

Aerobiosis↗
PubMed2006

Impact of polymorphism in sulfotransferase gene on the risk of lung cancer.

Sulfotransferases (SULTs) are very important multifunctional enzymes that catalyze sulfonate conjugation, which is an important pathway in the phase II metabolism of numerous endogenous and exogenous compounds. Sulfotransferase 1A1 (SULT1A1) is active toward a wide range of substrates, including environmental and tobacco carcinogens. This case-control study involved collection of peripheral blood samples (2-5 mL) of 103 lung cancer patients and 122 controls from North Indian subjects. The SULT1A1 polymorphism was determined by using a polymerase chain reaction-restriction fragment length polymorphism method. The association between polymorphisms in the SULT1A1 gene with the risk of lung cancer was estimated by computing odds ratios (OR) and 95% confidence intervals (95% CI), using a multivariate logistic regression analysis. We observed marginally increased risk for mutant genotype (AA) of SULT1A1 for lung cancer (OR = 1.4, 95% CI = 0.48-4.06). A statistically significant association was found for smokers between either of two SULT1A1 genotypes, GA (OR = 10.3, 95% CI = 3.48-31.78, P = 0.000002) or AA (OR = 3.9, 95% CI = 1.99-7.81, P = 0.0002), and lung cancer. The present study indicates that the SULT1A1 genotype may play an important role in the risk of developing lung cancer, especially in cigarette smokers.

Alleles↗
PubMed2006

Effect of shock and mixed nitrophenolic loadings on the performance of UASB reactors.

The effect of nitrophenolic shock loads on the performance of three bench-scale upflow anaerobic sludge blanket (UASB) reactors was studied using synthetic wastewater. Reactors R1, R2 and R3 were fed with 30 mg/L concentration of 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4-dinitrophenol (2,4-DNP), respectively, along with methanol (COD = 2000 mg/ L), sodium nitrate (NO3(-)-N=200mg/L), and other nutrients. The reactors were in continuous operation for more than 2 years before the shock loading study was performed. Five nitrophenolic shock loadings of 45, 60, 75, 90 and 120mg/L d were administrated by increasing the influent nitrophenolic concentration to 45, 60, 75, 90 and 120mg/L, respectively, while keeping hydraulic retention time as 24h. The shocks were given continuously for a period of 4 days before switching back to normal nitrophenolic loading (30mg/Ld). The reactors were allowed to recover to normal performance level before administrating the next nitrophenolic shock load. The study showed that the nitrophenolic shock load of as high as 120 mg/L d did not affect the reactors performance irreversibly. After resuming the normal nitrophenolic loading, it took almost 3-18 days for the reactors to recover from the shock effect. The study was further extended to assess the maximum possible mixed nitrophenolic loading (2NP:4NP:2,4:DNP = 1:1:1) to which 2,4-DNP acclimated granular sludge containing reactor (R3) can be exposed without hampering the reactor (R3) performance irreversibly. The reactor was able to achieve pseudo-steady-state at a mixed nitrophenolic loading of 180 mg/L d with more than 90% removal of all the three nitrophenols, but failed at a mixed nitrophenolic loading of 225 mg/Ld.

2,4-Dinitrophenol↗
PubMed2006

Urological complications of live related donor renal transplantation: 13 years' experience at a single center.

BACKGROUND: This study is a retrospective analysis of urological complications and their treatment in our series of live-donor renal transplantation. MATERIAL AND METHODS: The series comprised of 500 patients. All underwent extravesical ureteroneocystostomy and all except a few initial patients were stented. RESULTS: There were 92 complications in 82 patients (18.4%). Urinary leakage occurred in 1.2%. There were no intrinsic ureteric obstructions. Extrinsic ureteric obstruction occurred in 0.8% of cases. The incidence of UTI was 15.4% and of urethral strictures 1%. CONCLUSION: The technique of stented extravesical ureteroneocystomy has led to an extremely low rate of urological complications in our series, over a long time and in a substantial number of patients.

Adult↗
PubMed2005

Effect of corn root exudates on the degradation of atrazine and its chlorinated metabolites in soils.

DIMBOA (3,4-dihydro-2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-one), a major benzoxazinone of Poaceae plants, was isolated and purified from corn seedlings. The effect of isolated and purified DIMBOA on the degradation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], and its toxic breakdown products, desethylatrazine [2-chloro-4-amino-6-(isopropylamino)-s-triazine; DEA] and desisopropylatrazine [2-chloro-4-(ethylamino)-6-amino-s-triazine; DIA], was studied in the absence of plants using batch experiments, while the effect of corn root exudates on these compounds was determined in hydroponic experiments. Degradation experiments were performed in the presence and absence of 50 microM, 1 mM, or 5 mM DIMBOA resulting in ratios of DIMBOA to pesticide of 1:1, 20:1, and 100:1. We observed a 100% degradation of atrazine to hydroxyatrazine within 48 h at a ratio of DIMBOA to atrazine of 100:1. DIMBOA had the largest effect on atrazine, while it was about three times less effective on DEA and DIA. Corn (Zea mays L. cv. LG 2185) was exposed to 10 mg L(-1) of either atrazine, DEA, or DIA for 11 d in a growth chamber experiment. Up to 4.3 micromol L(-1) d(-1) of hydroxyatrazine were formed in the nutrient solutions by plants exposed to atrazine, while the formation of hydroxylated metabolites from plants exposed to DEA and DIA was smaller and also delayed. The formation of hydroxylated metabolites increased in the solution with plant age in all atrazine, DEA, and DIA treatments. HMBOA (3,4-dihydro-2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3-one), the lactam precursor of DIMBOA, and a tentatively identified derivative of MBOA (2,3-dihydro-6-methoxy-benzoxazol-2-one) were detected in the corn root exudates. Mass balance calculations revealed that up to 30% of the disappearance of atrazine and DEA, and up to 10% of DIA removal from the solution medium in our study could be explained by the formation of hydroxylated metabolites in the solution itself. Our results show that higher plants such as corn have the potential to promote the hydrolysis of triazine residues in soils by exudation of benzoxazinones.

Atrazine↗
PubMed2005

Role of early trabeculectomy in primary open-angle glaucoma in the developing world.

BACKGROUND: The lack of prospective data comparing early surgery and medical management in primary open-angle glaucoma (POAG) in the developing world led us to conduct a small randomised controlled clinical trial to evaluate acceptance and effectiveness of early trabeculectomy in these patients. METHODS: A total of 60 patients with moderately advanced POAG were randomised into three groups (Group I-Conventional medical management, Group II-Option for early trabeculectomy, Group III-Received an educational package about their disease before an option for early trabeculectomy). The patients were followed up for a period of 6 months for visual acuity, intraocular pressures (IOP), and subjective satisfaction. RESULTS: The three study groups were statistically similar with respect to mean IOP, demographic, and socio-economic profile. 35% of the patients accepted early surgery when offered a choice between early surgery and medical management in one of the groups. 65% of patients in another group expressed willingness for an early surgery after receiving health education on glaucoma. The mean IOP in the operated eyes was lower than the medically treated eyes at 2 weeks (16.6 vs 23.0 mmHg), 6 months (18.5 vs 22.8 mmHg), and 1-year review (17.9 vs 22.3 mmHg) (P<0.001). No significant difference was seen among the groups with regard to visual acuity and subjective satisfaction. CONCLUSION: There is a reasonable acceptance of early surgery in POAG patients in the developing world and increases on educating patients about their disease. Early surgery offers better IOP control with no long-term subjective adverse effects.

Adult↗
PubMed2005

In vivo cytogenetic effects of a commercially formulated mixture of cypermethrin and quinalphos in mice.

In vivo cytogenetic effects of commercially formulated cypermethrin (CYP, synthetic pyrethroid insecticide) and/or quinalphos (QUI, organophosphate insecticide), generally used in combination, were examined through chromosomal aberrations (CA) and micronucleus test (MT) in mice. Male mice were orally gavaged to a single dose of CYP/QUI commercial mixture (22, 44 or 67 mg/kg b.wt.) for 24h (CA) or 48 h (MT). Based on the concentrations of active ingredients of CYP and QUI present in the test doses of CYP/QUI mixture, mice were orally exposed to 0.66, 1.32 and 2 mg/kg of CYP or 4.4, 8.8 and 13.4 mg/kg of QUI. For reference, a group of five mice was intraperitoneally administered to cyclophosphamide (20 or 50 mg/kg) or orally gavaged to peanut oil for vehicle control. Exposure of CYP/QUI mixture inhibited the mitotic index (MI) and induced CA in a dose-dependent manner at 24 h; however, significant (p<0.01 or 0.001) frequencies of CA were observed at 44 mg/kg onwards, whereas inhibition of MI at 67 mg/kg. Independent exposure of QUI at 8.8 mg/kg onwards also significantly (p<0.01 or 0.001) inhibited MI and induced CA, whereas CYP at 2 mg/kg (highest concentration in CYP/QUI mixture) inhibited MI significantly but failed to induce CA. Chromatid breaks and fragments found to be frequent aberrations in all the test groups. Treatment of CYP/QUI mixture also induced micronucleus formation dose-dependently at 48 h, yet statistically significant (p<0.001) frequencies of micronucleated polychromatic erythrocytes (MNPCE) were observed at 44 mg/kg onwards. QUI (8.8 and 13.4 mg/kg) alone also induced significant frequencies of MNPCE, whereas frequencies of MNPCE observed with the CYP even at 2 mg/kg were comparable to that of vehicle control. Present findings indicate the genotoxicity potential of CYP/QUI mixture and suggest that the simultaneous presence of the toxic doses of CYP and QUI can lead to synergistic genotoxicity in mice and may pose mutagenic risk in human beings.

Administration, Oral↗
PubMed2005

Municipal sludge leachate-induced genotoxicity in mice--a subacute study.

Inappropriate disposal of municipal sludge (MS) results in the leaching of toxic metals and organic chemicals, which can contaminate the surface and ground water leading to the serious health hazards. In this study, the genotoxic potential of the leachate prepared from MS sample was examined in mouse bone marrow cells through chromosomal aberrations (CA), micronucleus test (MT) and comet assay. Analysis of metals and physicochemical parameters of the leachate was also carried out to correlate the genotoxic results. The dried sludge showed high concentrations of heavy metals, viz. Cr, Cu, Pb and Ni. However, in 10% leachate, concentrations of these metals were manifold lower than that of obtained in dried sludge. Male mice orally gavaged to leachates (0.1-0.4 ml/mouse/day) for 15 days revealed significant (P<0.01, P<0.001) inhibition of mitotic index (MI) and induction of chromatid/chromosome fragments and breaks in all the treatment groups. The effect was observed to be dose-dependent. Treatment of mice with leachates also induced significant (P<0.001) frequencies of micronucleated polychromatic erythrocytes (MNPCE). The results of comet assay revealed a statistically significant (P<0.05 and <0.01) DNA damage in bone marrow cells exposed to 0.2-0.4 ml/mouse/day. Findings of the present study indicate that the constant exposure of MS leachate can cause genotoxic effects in mammals and suggest risks in human population.

Animals↗
PubMed2005

Cytogenetic effects of commercial formulation of cypermethrin in root meristem cells of Allium sativum: spectroscopic basis of chromosome damage.

To validate the use of Allium sativum as a sensitive test model for genotoxicity, the cytogenetic effects of a commercial formulation of the pyrethroid insecticide, cypermethrin, were evaluated in the root meristem cells of A. sativum. Ultraviolet (UV) and Fourier transform infrared (FTIR) spectral measurements were also carried out to understand the interaction of cypermethrin with DNA. In a preliminary toxicity assay, the EC50 for Allium root growth was estimated to be 8 ppm. For the cytogenetic assay, root meristem cells were exposed to 1, 2, 4, 8 and 16 ppm of the test compound for 24 h, and either processed immediately for analysis or incubated in water for 24 h of recovery and then processed. Cells analyzed immediately after the exposure had a significant, dose-dependent inhibition of mitotic index (MI) and induction of mitotic and chromosomal aberrations (MAs and CAs). The 24 h recovery period reduced the effect of the test compound on the MI and percent aberrations; however, cells exposed to 8 and 16 ppm showed a significant frequency of aberrations despite the recovery period. One part per million cypermethrin was consistently negative in the assay. The data indicate that higher doses of cypermethrin produce toxicity, CAs and MAs in A. sativum. The present study indicates that A. sativum is a sensitive and reliable test system. A bathochromic shift observed in UV absorption spectra reveals that cypermethrin binds with DNA. Role of vibrational modes of the active site in the recognition and reaction of cypermethrin with DNA has been discussed. Based on spectroscopic data and structural properties, a possible mechanism has been proposed for the interaction of cypermethrin with DNA resulting in chromosomal aberrations.

Chromosome Aberrations↗
PubMed2005

Copper, zinc, and Cu/Zn ratio in carcinoma of the gallbladder.

INTRODUCTION: The exact role of copper and zinc in the etiology of carcinoma of the gallbladder is unclear. Some studies suggest the Cu/Zn ratio is a good indicator of the extent and prognosis in carcinoma of the gastrointestinal tract. The aim of the present study is to estimate the micronutrient profile and Cu/Zn ratio in the serum, tissues, and bile of patients with benign and malignant gallbladder diseases. METHODS: The present study was carried out in 60 patients comprising 30 each of carcinoma of the gallbladder and cholelithiasis, and 30 age and sex matched controls. Copper and zinc levels were estimated in blood, bile, and tissue using a Perkin Elmer Model 2380 Atomic absorption Spectrophotometer. RESULTS: The mean serum zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis and in healthy controls (P < 0.001). The mean serum copper levels were significantly higher in patients with carcinoma of the gallbladder as compared to patients with cholelithiasis and healthy controls (P < 0.001). Biliary and tissue zinc levels were significantly lower in patients with carcinoma of the gallbladder than in patients with cholelithiasis. Biliary and tissue copper levels were higher in patients with carcinoma of the gallbladder than in patients with cholelithiasis. The serum Cu/Zn ratio showed a gradual and significant increase from 1.11 in healthy controls to 1.35 in patients with cholelithiasis and 2.12 in patients with carcinoma of the gallbladder. The biliary and tissue Cu/Zn ratios were also significantly increased in patients with carcinoma of the gallbladder than in patients with cholelithiasis (P < 0.001). CONCLUSIONS: Our data support an association between lower zinc levels and consequently an increased Cu/Zn ratio and carcinoma of the gallbladder. Whether zinc supplementation has a protective effect in preventing carcinoma of the gallbladder needs to be studied further.

Bile↗