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Biomedical subjects

A Singh

Publications and source records attributed to A Singh.

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

Molluscicidal activity of Lawsonia inermis and its binary and tertiary combinations with other plant derived molluscicides.

Molluscicidal activity of leaf, bark and seed of Lawsonia inermis against Lymnaea acuminata and Indoplanorbis exustus was studied. Highest toxicity was observed in the seed of Lawsonia inermis. Toxicity of binary (1:1) and tertiary (1:1:1) combinations of the essential oil of cedar (Cedrus deodara Roxh) and neem (Azadirachta indica A. Juss), powder from bulb of garlic (Allium sativum Linn), and oleoresin extracted from rhizome of ginger (Zingiber officinale Rosc) with Lawsonia inermis and Embelia ribes fruit powder were studied against L. acuminata and I. exustus. L. inermis seed powder in combination with Cedrus deodara oil and Azadirachta indica oil was more toxic than their individual components and other combinations.

Animals↗
PubMed2001

Cytokine profile in human immunodeficiency virus positive patients with and without tuberculosis.

BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with a profound dysregulation of the immune system and alterations in the cytokine profile. Tuberculosis, a common opportunistic infection in HIV positive patients, leads to further immune suppression and a faster progression of the disease. This study was conducted to assess and compare the cytokine profiles in HIV positive subjects with and without pulmonary tuberculosis. METHODS: Twenty HIV positive patients and 20 controls were evaluated after being divided into four groups of 10 each--group 1--HIV positive patients without tuberculosis, group 2--HIV positive patients with pulmonary tuberculosis, group 3--healthy adults and group 4--HIV negative patients with pulmonary tuberculosis. After clinical evaluation, the CD4 cell counts and the cytokine profiles--interleukins (IL)-2, 4, 6, 10, 12, interferon gamma (IFN gamma) and tumour necrosis factor alpha (TNF alpha) were studied in all the subjects at the start and after three months of antituberculosis therapy. RESULTS: the CD4 cell counts were significantly lower in groups 1 and 2 compared to groups 3 (p < 0.01) and the counts in group 2 were significantly lower than in group 1 in both at baseline (p = 0.0076) and at three months (p = 0.089). The levels of the type 1 cytokines (IL-2, IL-12 and IFN gamma were significantly lower in patients in groups 1 and 2 compared to group 3 (p < 0.001 for both). The levels in group 2 were lower than in group 1 (p < 0.001). The type 2 cytokines (IL-4, IL-6, IL-10 and TNF alpha) were higher in group 1 and 2 compared to group 3, though statistically significant for IL-6 in group 1 (p < 0.05) and for IL-4, IL-6 and TNF alpha in group 2. A highly significant (p < 0.0001) positive correlation between CD4 cell counts and type 1 cytokines and a highly significant (p < 0.0001) negative correlation between CD4 cell counts and type 2 cytokines was observed. CONCLUSIONS: A decline in the type 1 and a rise in type 2 cytokines was observed in HIV infection. Patients in group 2 had the lowest CD4 cell counts, lowest levels of type 1 cytokines and highest levels of type 2 cytokines denoting maximum immunosuppression.

Adult↗
PubMed2001

Otitis media.

There is a high rate of use of antimicrobial drugs for otitis media in children. This article reviews the diagnostic considerations for acute otitis media. An extensive review of literature on this subject has been carried out in order to address the issues of indications, choice, appropriate doses of antimicrobial agents and the duration for which they should be used. It is important to distinguish acute otitis media from otitis media with effusion because antibiotics are seldom indicated for the latter condition. Oral amoxicillin remains first-line therapy for uncomplicated acute otitis media, a short course of antimicrobial therapy (five to seven days) may be appropriate in children two years of age or older with uncomplicated presentations. For clinical treatment failures after 3 days of amoxicillin, recommended antimicrobial agents include oral amoxicillin/clavulanate, cefuroxime axetil, cefprozil, cefpodoxime proxetil, and intramuscular (i.m.) ceftriaxone. Tympanocentesis for identification of pathogens and susceptibility to antimicrobial agents is recommended for selection of third-line agents.

Algorithms↗
PubMed2001

Evaluation of emission characteristics and compliance of emission standards for in-use petrol driven vehicles in Delhi.

The tail pipe CO (carbon monoxide) and HC (hydrocarbon) emission characteristics of in-use petrol driven vehicles were evaluated between November 1996 through September 1997 in Delhi. A total of 4300 vehicles were checked at CRRI Pollution Checking Centre. Approximately 90% of the total vehicles meet the prescribed CO emission standards even without following routine I/M practices. The age of the vehicles appeared to have influence on the emission characteristics. The non-compliance level was found to be higher for older vehicles. Insignificant correlation was observed between CO and HC emissions for all categories of in-use petrol driven vehicles. The emission reduction (gain) in CO and HC emissions was observed for two wheelers equipped with four-stroke engines and four wheelers fitted with catalytic converters over their respective conventional vehicles. The observed high compliance levels indicate that existing tail pipe emission standards are lenient and need to be reviewed. The emission standards are proposed for different categories of in-use petrol driven vehicles.

Air Pollutants↗
PubMed2000

Which patients with newly diagnosed prostate cancer need a radionuclide bone scan? An analysis based on 631 patients.

PURPOSE: Although radionuclide bone scans are frequently recommended as part of the staging evaluation for newly diagnosed prostate cancer, most scans are negative for metastases. We hypothesized that Gleason score, prostate-specific antigen (PSA), and clinical stage could predict for a positive bone scan (BS), and that a low-risk group of patients could be identified in whom BS might be omitted. METHODS: All patients who had both pathologic review of their prostate cancer biopsies and radionuclide BS at our institution between 1/90 and 5/96 were studied. Gleason score, PSA, and clinical stage (AJCC, 4th edition) were evaluated by univariate and multivariate analyses for their ability to predict a positive BS. Groups analyzed were Gleason of 2-6 vs. 7 vs. 8-10; PSA of 0-15 vs. greater than 15-50 vs. greater than 50; and clinical stage of T1a-T2b vs. T2c-T4. Univariate analysis using chi(2) and multivariate analysis using logistic regression were performed. RESULTS: Of the 631 consecutive patients, 88 (14%) had positive BS. Multivariate analysis (64 excluded due to missing PSA and/or clinical stage) showed Gleason score, PSA, and clinical stage to be significant independent predictors for positive BS (p < 0.002, p < 0.001, p < 0.001, respectively). The odds ratios were 5.25 (confidence interval [CI], 3.43-8.04) for PSA > 50 vs. 0-15; 2.25 (CI, 1.43-3.54) for Gleason of 8-10 vs. 2-6; 2.15 (CI, 1.54-2.99) for clinical stage T2c-T4 vs. T2b or less. Three of 308 (1%) had a positive BS in patients with Gleason 2-7, PSA of 50 or less, and clinical stage of T2b or less. In the subset of the same risk group with PSA of 15 or less, all 237 had negative bone scans. In patients with PSA greater than 50, 49/99(49.5%) had positive BS. CONCLUSION: Gleason score, PSA, and clinical stage were independent predictors for a positive radionuclide BS in newly diagnosed prostate cancer patients. PSA is the major predictor for positive BS. About one-half of the patients analyzed were in the low-risk group (Gleason 2-7, PSA < or = 50, clinical stage < or = T2b) and elimination of BS in these patients would result in considerable economic savings.

Analysis of Variance↗
PubMed2000

Combined 3-dimensional conformal radiotherapy and transperineal Pd-103 permanent implantation for patients with intermediate and unfavorable risk prostate cancer.

PURPOSE: To evaluate the efficacy and morbidity of combined 3-dimensional conformal radiation therapy (3D-CRT) and brachytherapy for intermediate/unfavorable risk prostate cancer. MATERIALS AND METHODS: Between May 1996 and November 1997, 65 patients with intermediate/unfavorable risk prostate cancer were treated with 3D-CRT (50.4 Gy) followed by a transperineal permanent Pd-103 implant. Patients with one or two adverse prognostic features (PSA > 10 and Gleason > or = 7) were classified as intermediate risk and unfavorable risk, respectively. Forty-seven patients (71%) had intermediate risk and 18 (29%) had unfavorable disease risk. The median age of this group was 65 years (range, 42-76 years), and the median pretreatment PSA level was 8.0 ng/ml (range, 1.7-42.0 ng/ml). The clinical stage of these patients was as follows: Tlc, 36 (55%); T2a, 27 (42%); T2b/T3, 2 (3%). Fifteen patients (23%) had a Gleason < or = 6, 41 patients (63%) were classified as Gleason 7, and 9 (14%) as Gleason > or = 8. Fifty-two (80%) received neoadjuvant androgen deprivation (NAAD) for cytoreduction. The median follow-up was 36 months (range, 24-42 months). RESULTS: The PSA relapse-free survival rate at 3 years was 87%, with a median PSA value at last follow-up of 0.25 ng/ml. The relapse-free survival was 90% for those who had an initial PSA < or = 10 ng/ml and 80% for patients who had an initial PSA > 10 ng/ml (p = 0.5). No difference in outcome was observed between patients with intermediate and unfavorable risk disease. Eight patients (13%) developed late Grade 2 rectal bleeding. Twenty-three patients (42%) required medication for urinary symptoms during the first 6 months after therapy. Three patients (5 %) noted rare stress incontinence at last follow-up. Of the 44 patients who were potent prior to therapy, 17 (26%) developed erectile dysfunction (ED). CONCLUSION: Although the follow-up is short, the early biochemical outcome of combined 3D-CRT and brachytherapy for intermediate/unfavorable risk prostate cancer is promising. While rectal toxicity is minimal, urinary side effects are more common. Further follow-up is necessary to fully evaluate the efficacy of this combined therapeutic approach.

Adult↗
PubMed2000

Characterization of native and recombinant falcipain-2, a principal trophozoite cysteine protease and essential hemoglobinase of Plasmodium falciparum.

Trophozoites of the malaria parasite Plasmodium falciparum hydrolyze erythrocyte hemoglobin in an acidic food vacuole to provide amino acids for parasite protein synthesis. Cysteine protease inhibitors block hemoglobin degradation, indicating that a cysteine protease plays a key role in this process. A principal trophozoite cysteine protease was purified by affinity chromatography. Sequence analysis indicated that the protease is encoded by a previously unidentified gene, falcipain-2. Falcipain-2 was predominantly expressed in trophozoites, was concentrated in food vacuoles, and was responsible for at least 93% of trophozoite soluble cysteine protease activity. A construct encoding mature falcipain-2 and a small portion of the prodomain was expressed in Escherichia coli and refolded to active enzyme. Specificity for the hydrolysis of peptide substrates by native and recombinant falcipain-2 was very similar, and optimal at acid pH in a reducing environment. Under physiological conditions (pH 5.5, 1 mm glutathione), falcipain-2 hydrolyzed both native hemoglobin and denatured globin. Our results suggest that falcipain-2 can initiate cleavage of native hemoglobin in the P. falciparum food vacuole, that, following initial cleavages, the protease plays a key role in rapidly hydrolyzing globin fragments, and that a drug discovery effort targeted at this protease is appropriate.

Amino Acid Sequence↗
PubMed2000

Antiproliferative effect of L-NAME on rat vascular smooth muscle cells.

The nitric oxide synthase (NOS) inhibitor L-NAME may have growth inhibitory effects in vivo. We investigated in vitro the potential growth inhibitory effects of three different NOS inhibitors: L-NAME (1 mM), LNMMA (1 mM) and aminoguanidine (0.5 mM), on fetal bovine serum (FBS) and platelet derived growth factor (PDGF-BB)-stimulated growth in cultured vascular smooth muscle cells (VSMCs). [3H]-thymidine incorporation into rat mesenteric VSMCs was measured as an index of VSMCs proliferation (DNA synthesis) and activation of extracellular signal regulated kinase (ERK1/2), a major signaling event in cell growth, was measured by western blot assay. PDGF-BB (0-5 ng/mL) and FBS (0-5%) increased [3H]-thymidine incorporation in a dose-dependent manner up to 6-10 fold. L-NAME significantly reduced PDGF-BB (5 ng/ml) and FBS (5%) stimulated DNA synthesis by 46% and 38% respectively. The increase of [3H]-thymidine incorporation induced by PDGF-BB and FBS was unaltered by L-NMMA. In contrast, aminoguanidine induced an increase in FBS and PDGF-BB-stimulated [3H]-thymidine incorporation of 64% and 34% respectively above cells not exposed to aminoguanidine. ERK1/2 phosphorylation induced by PDGF-BB and FBS was not affected by pre-treatment with L-NAME or aminoguanidine. In conclusion, NOS inhibitors differentially influence DNA synthesis in VSMCs: L-NAME inhibits FBS and PDGF-BB-stimulated cellular proliferation whereas aminoguanidine accentuates FBS and PDGF-BB-stimulated VSMCs proliferation. These phenomena are independent of the ERK1/2 pathway. The growth inhibitory effects of L-NAME may be related to differences in properties from other NOS inhibitors, and independent of its ability to inhibit NOS.

Animals↗
PubMed2000

Characterization of large plasmids encoding resistance to toxic heavy metals in Salmonella abortus equi.

Salmonella abortus equi vaccine strains were found to be resistant to high levels of toxic heavy metals--arsenic, chromium, cadmium, and mercury. The two strains 157 and 158 were resistant to ampicillin also. Curing of these strains resulted in loss of one or more resistance marker indicating plasmid borne resistance. Plasmid profile of strain 157 showed presence of three plasmids of 85, 54, and 0.1 Kb, whereas 158 strain showed presence of 85 Kb and 2 Kb plasmids. Plasmids were isolated from strain 157 and introduced into E. coli DH5alpha with a transformation efficiency of 2 x 10(3) transformants/microg DNA. Interestingly the transformants were resistant to antibiotics, heavy metals (As, Cr, Cd, Hg) and was also able to utilize citrate, a trait specific to Salmonella species. We report and establish for the first time the transferable large plasmids encoding resistance to various heavy metals, antibiotics and biochemical nature of S. abortus equi.

Ampicillin Resistance↗
PubMed2000

PCB 118 induces ultrastructural alterations in the rat liver.

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that bioaccumulate in the food chain and thus pose a health risk to humans and other animals. In this study, PCB 118 was added to the diets of Sprague Dawley rats for 13 weeks in concentrations of 2, 20, 200, 2000 p.p.b. to the females and 10, 100, 1000 and 10000 p.p.b. to the males. The chemical was dissolved in corn oil; animals that served as the control received corn oil in the diets devoid of PCB. Use of transmission electron microscopy and stereology revealed significant (P<0.05) elevation in the mean volume fraction of smooth reticulum profiles (20 p.p.b.), peroxisomes (200, 2000 p.p.b.) and lipid droplets (2000 p.p.b.) in the females. Hepatocytes from the males exhibited a significant increase in the mean volume fraction of lipid droplets at 10000 p.p. b. (P<0.05). Interactions between large quantity of estrogen and the PCB probably would account for more profound alterations in the liver of female Sprague-Dawley rats than in the males.

Animals↗
PubMed2000

Inhibition of deoxyglucose uptake in MCF-7 breast cancer cells by 2-methoxyestrone and 2-methoxyestrone-3-O-sulfamate.

Most cancer cells are dependent on glucose uptake to fulfil their energy requirements. In the present investigation we have examined the ability of 2-methoxyestrone (2-MeOE1), 2-methoxyestradiol (2-MeOE2), 2-methoxyestrone-3-O-sulfamate (2-MeOEMATE), and a number of related compounds, to inhibit 2-deoxy-D-[1-(3)H]-glucose uptake in MCF-7 breast cancer cells. Glucose uptake was shown to be linear with respect to cell number and time over a 5-35min period. 2-MeOE2, 2-MeOE1 and 2-MeOEMATE inhibited glucose uptake by 25-49% at 10 microM. 2-Hydroxyestradiol and estrone sulfate had little effect on glucose uptake, whereas estrone glucuronide inhibited uptake by 29%. There is evidence that 2-methoxyestrogens may exert an anti-mitotic effect on cells by stabilizing microtubules in a similar manner to that of paclitaxel. We therefore examined the effect of exposing cells to 2-MeOEMATE or paclitaxel for 24 h on basal or insulin stimulated glucose uptake. Using these conditions, 2-MeOEMATE and paclitaxel inhibited basal glucose uptake by 50 and 22%, respectively, and insulin stimulated uptake by 36 and 51%, respectively. The development of drugs that can inhibit glucose uptake could have therapeutic potential for the treatment of breast cancer.

2-Methoxyestradiol↗
PubMed2000

Evaluation of carcinogenic and co-carcinogenic potential Quinalphos in mouse skin.

Quinalphos [O,O-diethyl-O-quinoxalinyl-phosphorothidate] is an organophosphorus pesticide with tremendous utility in mixed pest control due to its insecticidal and acaricidal properties. Apart from its pesticidal property, Quinalphos is known to induce various toxic effects in nontarget species and experimental animals. No studies have been conducted to evaluate the carcinogenic/co-carcinogenic hazards associated with Quinalphos exposure. In the present set of investigations, the tumorigenic potential of Quinalphos has been evaluated following topical exposure in Swiss albino mice. Long-term animal bioassays conducted for the evaluation of complete carcinogenic, tumour-initiating and tumour-promoting potential of Quinalphos revealed that it has only tumour-initiating potential at a dose of 10 mg/kg body weight (b.wt.), in the two-stage mouse skin model of carcinogenesis. Quinalphos exposure failed to produce neoplasia when tested for complete carcinogenic activity at all three tested dose levels or tumour promoting activity.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Adrenocorticosterone alterations in male, albino mice treated with Trichopus zeylanicus, Withania somnifera and Panax ginseng preparations.

The levels of corticosterone were estimated by the HPLC method in the adrenal glands of stressed (5 h constant swimming) male albino mice treated with Trichopus zeylanicus, Withania somnifera and Panax ginseng preparations and compared with non-treated stressed and normal controls. The treatments increased the corticosterone levels in all the groups. The physical endurance (increased survival time) of swimming mice also increased in all the treated groups, except in the group treated with Withania somnifera powder (500 mg/kg, p.o.).

Adrenal Glands↗
PubMed2000

Use of hyperbaric oxygen chamber in the management of radiation-related complications of the anorectal region: report of two cases and review of the literature.

PURPOSE: This article was undertaken to present two cases of nonhealing ulcers that occurred after primary radiation therapy and local excision of suspected residual or recurrent anal carcinomas. Both patients responded favorably to hyperbaric chamber treatment. Review of the literature is discussed, including cause, clinical presentation, diagnosis, and options for management of radiation-related complications in the anorectal region and use of hyperbaric oxygen treatment in colorectal surgery. METHODS: The cases of two patients with recurrent or residual anal carcinomas were reviewed. Objective clinical, laboratory test, and intraoperative findings were implemented to define this pathologic entity precisely, results of its treatment, and management of radiation-related complications. RESULTS: The study shows clinical effectiveness of hyperbaric chamber treatment for nonhealing wounds in the previously radiated anorectal region. The refractory wounds of both our patients healed. The patients were rendered free of symptoms. CONCLUSIONS: Substantial pathologic changes in the irradiated tissues leading occasionally to nonhealing radiation proctitis are relatively infrequent consequences of radiation therapy for pelvic malignancies. Excisional and incisional biopsies of the radiation-injured tissues result in chronic ulcers accompanied by debilitating symptoms. Hyperbaric chamber treatment seemed to be a very effective means of therapy of radiation proctitis and nonhealing wounds in the involved anorectal region after conventional therapy had failed.

Anus Diseases↗
PubMed2000

Tetanus immunization among adolescent girls in rural Haryana.

This survey was undertaken to estimate tetanus immunization coverage of adolescent girls in a selected rural community of Haryana and to ascertain the knowledge of these girls and their mothers about tetanus. The study period was between April 1996-March 1997. A 30-cluster immunization coverage house to house survey was carried out by a female social worker. The total population covered was 30,448. Twelve roadside villages were selectively chosen. Eleven year and 17 year old girls (210 in each group) were surveyed for coverage evaluation. For K.A.P. survey 114 girls (aged 17 years) and 98 mothers (of 11 year old girls) were interviewed. Chi square, percentage and 95% confidence interval were used for statistical analysis. Coverage for tetanus immunization was 44.3% among 17 year old girls and 26.7% among 11 year old girls. The coverage was better (35%) among school going girls as compared to non-school going girls (13%). Correct immunization schedule of pregnant women was told by 16 (7.5%) respondents. None of them told the correct immunization schedule for children. Death was told as the main danger from tetanus by 172 (81%) respondents. Most (98%) were aware of the role of clean-stump (umbilical cord) at the time of delivery in the etiology of tetanus neonatorum. Tetanus immunization coverage needs to be improved among adolescents. They also need to be educated on various aspects of tetanus.

Adolescent↗
PubMed2000

I-cell disease (Mucolipidosis II).

I-cell disease (Mucolipidosis II) is one of the lysosomal storage diseases which presents in the neonatal period, and within six months will phenotypically resemble the severe forms of the group of disorders called the "mucopolysaccharidoses" but without mucopolysacchariduria. In Mucolipidosis II, fibrocytes exhibit "abnormal lysosomes". Activities of several lysosomal enzymes are low in fibroblast cultures but high in mucolipidosis II serum. We present a patient with I-cell disease diagnosed on the basis of clinical, radiological and biochemical features. The mother of this child was pregnant and the fetus was also found to be affected.

Child, Preschool↗