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Biomedical subjects

S K Gupta

Publications and source records attributed to S K Gupta.

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

The role of atypical pathogens in community-acquired pneumonia.

The atypical pathogens in community-acquired pneumonia traditionally have included Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella spp. Recent studies documenting their epidemiology and clinical characteristics have shown that these organisms are indistinguishable from the pneumococcus. Furthermore, therapy no longer depends on the specific bacterial cause of community-acquired pneumonia. Etiologic diagnosis is still difficult, although new methods are becoming available. This article focuses on these issues and on why the term atypical is no longer meaningful.

Chlamydophila Infections↗
PubMed2001

Hybrid reactor for priority pollutant-trichloroethylene removal.

The present study was initiated to explore the potential of a hybrid biological reactor, combining trickling filter (TF) and activated sludge process (ASP), to treat wastewater containing trichloroethylene (TCE) at ambient temperature at different hydraulic retention time (HRT). The biofilm acclimation was achieved in 55-60 days with gradual increase in TCE concentration from 1 mg/l to 100 mg/l with a parallel increase in the concentration of substrate sodium acetate and other nutrients. COD and TCE concentration were taken as prime parameters for monitoring the growth of biofilm. During acclimation COD removal varied between 54.6-97.5% while TCE was removed 72.6-99.9%. HRT study was performed after acclimation. The removal efficiency increased with decreasing flow rate with maximum TCE removal (99.99%) at 6 l/d corresponding to an HRT of 28 h (TF 18 h + ASP 10 h). This was followed by a C:N:P ratio study. A ratio of 100:20:1 led to the sustenance of maximum TCE removal. Maximum TCE removal (99.99%) was observed at a substrate:cosubstrate ratio of 100:1. A pH of 7.4 +/- 0.2 was found to be optimum for degradation. Finally, volatilization losses were estimated to be 18.5%. A mass balance gave an efficiency of 81.51% for biological removal of TCE.

Biodegradation, Environmental↗
PubMed2001

Simultaneous carbon and nitrogen removal from high strength domestic wastewater in an aerobic RBC biofilm.

High strength domestic wastewater discharges after no/partial treatment through sewage treatment plants or septic tank seepage field systems have resulted in a large build-up of groundwater nitrates in Rajasthan, India. The groundwater table is very deep and nitrate concentrations of 500-750 mg/l (113-169 as NO3(-)-N) are commonly found. A novel biofilm in a 3-stage lab-scale rotating biological contactor (RBC) was developed by the incorporation of a sulphur oxidising bacterium Thiosphaera pantotropha which exhibited high simultaneous removal of carbon and nitrogen in fully aerobic conditions. T. pantotropha has been shown to be capable of simultaneous heterotrophic nitrification and aerobic denitrification thereby helping the steps of carbon oxidation, nitrification and denitrification to be carried out concurrently. The first stage having T. pantotropha dominated biofilm showed high carbon and NH4(+)-N removal rates of 8.7-25.9 g COD/m2 d and 0.81-1.85 g N/m2 d for the corresponding loadings of 10.0-32.0 g COD/m2 d and 1.0-3.35 g N/m2 d. The ratio of carbon removed to nitrogen removed was close to 12.0. The nitrification rate increased from 0.81 to 1.8 g N/m2 d with the increasing nitrogen loading rates despite a high simultaneous organic loading rate. However, it fell to 1.53 g N/m2 d at a high load of 3.35 g N/m2 d and 32 g COD/m2 d showing a possible inhibition of the process. A simultaneous 44-63% removal of nitrogen was also achieved without any significant NO2(-)-N or NO3(-)-N build-up. The second and third stages, almost devoid of any organic carbon, acted only as autotrophic nitrification units, converting the NH4(+)-N from stage 1 to nitrite and nitrate. Such a system would not need a separate carbon oxidation step to increase nitrification rates and no external carbon source for denitrification. The alkalinity compensation during denitrification for that destroyed in nitrification may also result in a high economy.

Biofilms↗
PubMed2001

A comparison of the effects on saliva output of oxybutynin chloride and tolterodine tartrate.

BACKGROUND: Oxybutynin chloride and tolterodine tartrate are anticholinergic agents used to suppress involuntary bladder contractions in urinary incontinence. They act by inhibiting binding of acetylcholine to the muscarinic receptors in the detrusor muscle of the bladder. The same types of muscarinic receptors are found in the salivary glands; thus anticholinergic agents may decrease saliva production and cause dry mouth, a commonly cited reason for discontinuation of therapy. OBJECTIVE: The primary objective of this study was to compare saliva output, which is an objective measure of dry mouth, in subjects taking immediate- or extended-release oxybutynin, tolterodine, or placebo. METHODS: This was a single-site, single-dose, randomized, double-blind, 4-treatment, 4-period crossover study. Subjects were randomly assigned to 1 of 4 treatment sequences that included extended-release oxybutynin 10 mg, tolterodine 2 mg, immediate-release oxybutynin 5 mg, and placebo. Saliva output was measured objectively before dosing with each treatment and at 0.5, 1, 2, 3, 4, 6, 8, 10, and 12 hours after dosing. RESULTS: Thirty-six healthy adult volunteers (22 women and 14 men) participated in the study. They ranged in age from 19 to 42 years (mean, 27 years). Thirty-one were white, 3 Asian, and 2 black. There were no significant differences in predose saliva output between the 4 study groups. With placebo, saliva output increased throughout the day. Saliva output was maintained at predose levels throughout the day with extended-release oxybutynin. Two hours after dosing with tolterodine and immediate-release oxybutynin, saliva output decreased nearly 0.5 g in specimens collected over 2 minutes. All 3 active treatments were associated with lower saliva output compared with placebo. Extended-release oxybutynin and tolterodine were similar with respect to area under the saliva concentration-time curve but were associated with significantly greater saliva output than was immediate-release oxybutynin (P < 0.01). There were no serious adverse events (AEs) in this study. AEs were similar between treatments, although the incidence of headache was higher in the active-treatment groups than with placebo. CONCLUSIONS: Objective assessment of saliva output in healthy adult volunteers indicated that extended-release oxybutynin and tolterodine had less impact on saliva output than did conventional immediate-release oxybutynin, suggesting that they may yield lower levels of dry mouth.

Adult↗
PubMed2001

Topical ciprofloxacin-dexamethasone combination therapy after cataract surgery: randomized controlled clinical trial.

PURPOSE: To determine the efficacy of a combination of ciprofloxacin 0.3% and dexamethasone 0.1% eyedrops in controlling immediate inflammation after cataract surgery. SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences and Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India. METHODS: This randomized controlled clinical trial comprised 61 patients, 31 of whom were treated with a combined ciprofloxacin-dexamethasone suspension (study group) and 30, with a standard formulation of betamethasone and neomycin eyedrops (control group). One and 7 days postoperatively, pain, lid edema, lacrimation, conjunctival congestion, aqueous flare and cells, and side effects were noted. A conjunctival swab for bacteria and a fungus culture were sent for evaluation 7 days postoperatively. RESULTS: At 7 days, there was no statistically significant difference between groups in lid edema, conjunctival congestion, anterior segment inflammation, lacrimation, or pain. Two patients in the ciprofloxacin-dexamethasone group noted white deposits in and around the eye that resolved after the dose was reduced to 4 times a day. No patient reported or developed an allergic reaction to either drug combination. CONCLUSION: A ciprofloxacin-dexamethasone combination was effective in controlling inflammation after cataract surgery.

Administration, Topical↗
PubMed2001

Biotransformation of nitrophenols in upflow anaerobic sludge blanket reactors.

Four identical bench-scale upflow anaerobic sludge blanket (UASB) reactors, R1, R2, R3 and R4, were used to assess nitrophenols degradation at four different hydraulic retention times (HRT). Reactor R1 was used as control, whereas R2, R3, and R4 were fed with 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), and 2,4-dinitrophenol (2,4-DNP), respectively. The concentration of each nitrophenol was gradually varied from 2 to 30 mg/l during acclimation. After acclimation reactors were operated under steady-state conditions at four different HRTs--30, 24, 18, and 12 h, to study its effect on the removal of nitrophenols. Overall removal of 2-NP and 4-NP was always more than 99% but 2,4-DNP removal decreased from 96% to 89.7% as HRT was lowered from 30 to 12 h. 2-Aminophenol (2-AP), 4-aminophenol (4-AP) and 2-amino,4-nitrophenol (2-A,4-NP) were found to be the major intermediates during the degradation of 2-NP, 4-NP and 2,4-DNP, respectively. Out of the total input of nitrophenolic concentration (30 mg/l), on molar basis, about 41.248.4% of 2-NP, 59.4-68% of 4-NP, 30-26.6% of 2,4-DNP was recovered in the form of their respective amino derivatives at 30-12 h HRT. COD removal was 98-89%, 97-56%, 97-52%, and 94-46% at 30-12 h HRT for R1, R2, R3 and R4, respectively. Average cell growth was observed to be 0.15 g volatile suspended solid (VSS) per g COD consumed. Methanogenic inhibition was observed at lower HRTs (18 and 12 h), however denitrification was always more than 99% with non-detectable level of nitrite. The granules developed inside the reactors were black in color and their average size varied between 1.9 and 2.1 mm.

Biomass↗
PubMed2001

Cardioprotective potential of ocimum sanctum in isoproterenol induced myocardial infarction in rats.

Myocardial infarction (MI) was produced in rats with 85, 200 and 300 mg/kg of isoproterenol (ISO) administered subcutaneously (sc) twice at an interval of 24 h. Shift in antioxidant parameters, lactate dehydrogenase (LDH) together with morphological and histopathological changes were investigated. Two hundred mg/kg ISO dose was selected for the present study as this dose offered significant alteration in biochemical parameters along with moderate necrosis in heart. Effect of pre- and co-treatment of hydroalcoholic extract of Ocimum sanctum (Os) at different doses (25, 50, 75, 100, 200 and 400 mg/kg) was investigated against ISO (200 mg/kg) induced myocardial infarction in rats. Modulation of various biochemical parameters and membrane integrity was studied. Os at the dose of 25, 50, 75 and 100 mg/kg reduced significantly glutathione (GSH), superoxide dismutase (SOD) and LDH levels. It also inhibited the lipid peroxidation as observed by the reduced thiobarbituric acid reactive substances (TBARS) levels. In the present study Os at the dose of 50 mg/kg was found to demonstrate maximum cardioprotective effect. Above results were further confirmed by histopathological findings. Thus from the present study it is concluded that Os may be of therapeutic and prophylactic value in the treatment of MI.

Animals↗
PubMed2001

Cloning and relative expression analysis of rat stromal cell derived factor-1 (SDF-1)1: SDF-1 alpha mRNA is selectively induced in rat model of myocardial infarction.

Stromal cell derived factor-1 (SDF-1) is a member of the non-ELR subfamily of CXC chemokines. SDF-1 and its receptor, CXCR4, are essential for cardiogenesis, hematopoiesis, and vasculogenesis during embryonic development, in addition to involvement in chemotaxis of leukocyte subsets and endothelial cells. In order to study SDF-1 expression in a rat model of myocardial infarction, we cloned and functionally expressed the rat SDF-1alpha orthologue. Rat SDF-1alpha is highly conserved, with >95% identity to its known human, feline, and murine counterparts. Constitutive expression of SDF-1 mRNA was observed in heart, brain, liver, and kidney. Significantly, apart from the SDF-1alpha and beta splice variants, expression of the recently identified SDF-1gamma was uniquely abundant in the heart. SDF-1alpha mRNA was selectively induced in permanent coronary artery occlusion model of myocardial infarction in rat, while SDF-1gamma remained unchanged. Such modulation of SDF-1alpha mRNA expression may be indicative of its role in the inflammatory events in cardiovascular disease.

Animals↗
PubMed2001

Unique clinical characteristics of primary hyperparathyroidism in India.

BACKGROUND: The features of primary hyperparathyroidism (PHPT) in developing countries have rarely been examined. This study explored the clinical characteristics of PHPT in India with the hypothesis that this may improve understanding of the pathogenesis of the disease worldwide. METHODS: Consecutive patients with PHPT (24 women, five men) were examined prospectively before and after parathyroidectomy. RESULTS: All patients had osteitis fibrosa cystica with a median symptom duration of 2.5 (range 1-26) years. Single or multiple fragility fractures were present in 14 patients (eight were bedridden); 20 had brown tumours. Mean preoperative serum calcium was 3.1 mmol/l, while mean serum intact parathyroid hormone (iPTH) and total alkaline phosphatase (ALP) levels were 17-fold and 12-fold higher than normal respectively. Nine patients had overt renal damage, mainly nephrocalcinosis. Parathyroidectomy invariably resulted in severe hypocalcaemia, necessitating long-term vitamin D treatment. The mean parathyroid gland weight was 8.6 (range 2.0-36.6) g and features of carcinoma were found in four patients. Serum calcidiol level correlated inversely (P < 0.05) with serum iPTH and ALP, and parathyroid gland weight. CONCLUSION: PHPT in Indians is a severe, symptomatic disorder with skeletal, muscular and renal manifestations at a young age. The presence of this severe variant of PHPT in vitamin D-sufficient Indians, and the lack of skeletal disease in other vitamin D-deficient populations, raises the possibility of additional pathogenetic factors.

Adolescent↗
PubMed2001

Effect of OROS controlled-release delivery on the pharmacokinetics and pharmacodynamics of oxybutynin chloride.

UNLABELLED: Aims : Dry mouth is a common side-effect seen with immediate-release oxybutynin (IR-Oxy). Ditropan XL [(Oxy-XL), a controlled-release formulation of oxybutynin chloride, is a once-daily oral dosage form that incorporates the OROS technology. Dry mouth as the pharmacodynamic measure was compared between Oxy-XL and IR-Oxy administration. The steady state stereospecific pharmacokinetics were also established for the two formulations and the kinetic-dynamic relationship of oxybutynin was examined. METHODS: This was a randomized, repeated-dose, double-blind, two-treatment, two-period, crossover study. After a baseline assessment day, volunteers were randomly assigned to one of two treatment sequences and received 4 days of each treatment with a washout period of 7 days between treatments. The treatments were: 1) Oxy-XL 10 mg in the morning and placebo 8 h later, and 2) IR-Oxy 5 mg in the morning and again 8 h later. Volunteers assessed dry mouth severity subjectively using a 100 mm visual analogue scale, VAS (Baseline, treatment days 1 and 4) and objectively by collecting saliva (Baseline and treatment day 4) before dosing and every hour after the morning dose for approximately 16 h. Several blood samples were collected during each treatment, with frequent sampling on day 4 to analyse for plasma R- and S-oxybutynin and R- and S-desethyloxybutynin concentrations. RESULTS: Relatively constant plasma concentrations of oxybutynin and its metabolite were seen over 24 h following Oxy-XL administration with the degree of fluctuation being much lower (P = 0.001; 66% to 81% reduction for the various analytes) than IR-Oxy. Compared with IR-Oxy, Oxy-XL yielded higher (131% and 158% for the R- and S-isomer, respectively) oxybutynin and lower (62% and 78% for the R- and S-isomer, respectively) desethyloxybutynin bioavailability, suggesting reduced first-pass metabolism. Saliva output (area under the effect curve) was significantly higher [P = 0.001; 37% (95% confidence interval: 24, 51%)] with Oxy-XL than with IR-Oxy and, accordingly, dry mouth severity (VAS) integrated over the day was significantly lower with Oxy-XL. The decrease in saliva output and the consequent increase in dry mouth severity correlated with the metabolite R-desethyloxybutynin concentration, and no apparent relationship was observed with the R-oxybutynin concentration. This suggests that the metabolite may contribute to the dry mouth. Therefore, the reduction in metabolite exposure with Oxy-XL may be a possible explanation for the observed decrease in dry mouth severity with OXY-XL compared with IR-Oxy. CONCLUSIONS: Oxy-XL maintains relatively constant plasma drug and metabolite concentrations and minimizes first-pass metabolism of oxybutynin. The metabolite appears to contribute to dry mouth associated with oxybutynin, and following Oxy-XL metabolite exposure is reduced compared with IR-Oxy. Consequently less dry mouth was observed with Oxy-XL as compared with IR-Oxy.

Administration, Oral↗
PubMed2001

Population pharmacokinetic analysis of pegylated interferon alfa-2b and interferon alfa-2b in patients with chronic hepatitis C.

BACKGROUND: This study quantified pharmacokinetic changes in pegylated and nonpegylated interferon alfa-2b during 48 weeks of treatment and the influences of covariates on the basis of sparsely sampled serum concentrations and activity values. Possible relationships between pharmacokinetic and pharmacodynamic variables were investigated. METHODS: Patients with chronic hepatitis C were enrolled in a clinical trial that compared the efficacy of pegylated interferon alfa-2b with interferon alfa-2b. Single blood samples were obtained from each patient at weeks 4, 12, 24, 36, and 48. Three pharmacostatistical models were developed for 2 immunoassays and 1 bioassay. RESULTS: Apparent clearance values of pegylated interferon alfa-2b and interferon alfa-2b at the end of treatment declined 33.7% and 80.0%, respectively, from their week 4 values. Bioactivity increased 41% to 58% at week 48 for different treatment groups. Changes were greatest in the first weeks of administration and diminished during the subsequent months. Body weight had a modest positive effect on clearance values and activity. Within each dose level, no significant associations were observed between pharmacokinetic variables and any pharmacodynamic variables (hepatitis C virus--RNA responses or changes in neutrophils and platelets). CONCLUSIONS: This analysis confirms earlier observations of progressive pharmacokinetic changes in the patients with hepatitis C during 48 weeks of treatment. The absence of a relationship between toxicity or efficacy variables and interferon concentration or activity (within a dose level) suggests that clinical management of patients (eg, for efficacy or to manage toxicity) should be based on clinically derived dosing guidelines rather than on serum concentration or activity criteria.

Adolescent↗
PubMed2001

Purified and refolded recombinant bonnet monkey (Macaca radiata) zona pellucida glycoprotein-B expressed in Escherichia coli binds to spermatozoa.

Bonnet monkey (Macaca radiata) zona pellucida glycoprotein-B (bmZPB), excluding the N:-terminal signal sequence and the C:-terminus transmembrane-like domain, has been expressed in Escherichia coli as polyhistidine fusion protein. A requirement of 4 M urea to maintain the purified protein in soluble state rendered it unsuitable for biological studies. Purification of refolded r-bmZPB without urea and devoid of lower molecular weight fragments was achieved by following an alternate methodology that involved purification of inclusion bodies to homogeneity and solubilization in the presence of a low concentration of chaotropic agent (2 M urea) and high pH (pH 12). The solubilized protein was refolded in the presence of oxidized and reduced glutathione. The circular dichroism spectra revealed the presence of both alpha helical and beta sheet components in the secondary structure of the refolded r-bmZPB. The binding of the refolded r-bmZPB to the spermatozoa was evaluated by an indirect immunofluorescence assay and also by direct binding of the biotinylated r-bmZPB. The binding was restricted to the principal segment of the acrosomal cap of capacitated bonnet monkey spermatozoa. In the acrosome-reacted spermatozoa a shift in the binding pattern of r-bmZPB was observed and it bound to the equatorial segment, postacrosomal domain, and midpiece region. Binding of biotinylated r-bmZPB was inhibited by cold r-bmZPB as well as by monoclonal and polyclonal antibodies generated against r-bmZPB. These results suggest that nonglycosylated bmZPB binds to capacitated as well as acrosome-reacted spermatozoa in a nonhuman primate and may have a functional role during fertilization.

Animals↗
PubMed2001

Is esophagogastroduodenoscopy necessary in all caustic ingestions?

BACKGROUND: It is unclear whether symptoms alone can identify patients with caustic ingestion who will benefit from esophagogastroduodenoscopy (EGD). The published data are contradictory. The purpose of the current study was to determine the relationship between initial symptoms and EGD findings in patients with caustic ingestion. METHODS: Chart review of all caustic ingestions who underwent EGD during a 4-year period (December 1993 through November 1997). RESULTS: Twenty-eight patients (15 girls; mean age, 2.7 years (range, 0.92-13.33) underwent EGD after caustic ingestion. Fourteen percent (4/28) of patients were asymptomatic, and findings on endoscopy were normal. Another 57% (16/28) had normal endoscopic findings, although all were symptomatic. Twenty-nine percent (8/28) of patients had esophageal injury on EGD, and all were symptomatic. Esophageal injury was graded as 1 (mucosal erythema), 2 (superficial burns; noncircumferential) or 3 (deep burns; circumferential). The injury was grade 1 in three of eight patients and grade 2 in two; all had one symptom each. Grade 3 injury was found in three of eight patients: two had two symptoms (drooling and vomiting, drooling and stridor), and one had one symptom (dysphagia). All patients with grade 3 injury subsequently underwent esophageal dilations. Follow-up information was secured for two of the three patients with grade 1 injury and both patients with grade 2 injury at 34.3 months (range, 24-50) after the ingestion, and all were asymptomatic. Of the 20 patients with absence of esophageal mucosal damage, follow-up data were available for 15 patients at 37.2 months (range, 7-63) after the event and all were well. CONCLUSIONS: All patients with clinically significant injury (grades 2 and 3) were symptomatic at initial assessment. No single symptom or combination of symptoms could identify all patients with esophageal injury. All asymptomatic patients had normal findings on endoscopic examinations. Esophagogastroduodenoscopy seems unnecessary in asymptomatic patients with alleged caustic ingestion. A larger, prospective study would be necessary to unequivocally answer this clinically important question.

Adolescent↗
PubMed2001

Experience with juvenile polyps in North American children: the need for pancolonoscopy.

We report a recent experience with juvenile polyps (JP) in a large cohort of North American children to determine if a pancolonoscopy (PC) is needed in all children with suspected polyps. We reviewed hospital charts of all patients with JP seen over a 9-yr period (January, 1990-October, 1998). A total of 331 JP were encountered during 195 procedures in 184 patients (64% males, 88% white, mean age 5.93 yr [range 0.42-15.5 yr], median age 4.84 yr). Painless rectal bleeding was the commonest symptom. PC was performed in 42% (82/195) of procedures, and 177 JP were encountered: 54% (97/177) were in the rectosigmoid colon, 14% (24/177) were in the descending colon, and 32% (56/177) were proximal to the splenic flexure (i.e., proximal polyps). Overall, proximal polyps were seen in 37% (31/82) of PC. Only proximal polyps were noted in 12% (10/82) of PC. Five patients were re-endoscoped after an initial limited examination because of continuing symptoms from proximal polyps. All but one of the polyps had typical features of a JP on histological examination. Though most JP are located in the left colon, a PC should be the initial procedure because: 1) 37% of PC revealed proximal polyps, 2) 32% of polyps were located proximal to splenic flexure, 3) persistence of symptoms from missed proximal polyp(s) necessitates a repeat study with attendant risks, and 4) there is a possibility of malignant transformation in an unidentified JP.

Adenomatous Polyposis Coli↗
PubMed2001

The use of a newspaper insertion to promote DIY testing of vision in India.

BACKGROUND: The mass media have the potential to motivate people to participate in self appraisal of their own health status. An innovative communication package was designed to help people to examine vision at home. The impact of publishing the "do it yourself" (DIY) kit in Indian newspapers was evaluated. METHODS: A pretested bilingual vision testing kit was published in three newspapers. The kit comprised four tumbling Es corresponding to 6/12 line of Snellen's optotypes. Directions on using the kit were enclosed. 3 -7 days after publication of the kit, a telephone survey of newspaper readers was undertaken to evaluate the impact and cost effectiveness. RESULTS: 603 people were contacted over the telephone. 125 (20.73%) subscribed to the newspaper carrying the DIY insertion. 43.2% (54) noticed the insertion of which 88.89% (48) read the enclosed instructions carefully. 58.33% respondents felt sufficiently motivated to contact an ophthalmologist. Graduates had a 3.83 times higher probability of reading the communication insertion compared with others. Differences in relation to other demographic variables were not statistically significant. CONCLUSIONS: Newspapers are an excellent medium for communicating self appraisal kits for vision testing. The medium is cost effective and has significant reach in the urban agglomerates of India.

Adolescent↗