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Biomedical subjects

S Pandey

Publications and source records attributed to S Pandey.

At least 19 recordsLinked to original sources
PubMed2006

Tacrolimus (Pan Graf) as de novo therapy in renal transplant recipients in India.

The safety and efficacy of tacrolimus in transplantation is well established. However, tacrolimus has only recently been available in India. We report an initial experience using tacrolimus as de novo therapy in a living related renal transplant program. Fifty-two consecutive recipients of living renal allografts were treated with tacrolimus, mycophenolate mofetil, or azathioprine and steroids. The dose of tacrolimus was adjusted to keep trough levels at 10 to 12 ng/mL in the first 3 months, 8 to 10 ng/mL in the next 3 months, and 5 to 8 ng/mL thereafter. Any evidence of graft dysfunction was evaluated by graft biopsy. The effect of this regimen on the lipid profile as well as the incidence of posttransplant diabetes mellitus was evaluated in an Indian population. All patients were followed for periods ranging from 6 to 72 weeks (mean = 29 weeks). The incidence of acute rejection was 3.84%; 17.3% developed posttransplant diabetes mellitus. Graft and patient survivals at the current follow-up were 100% and 96.26%. In conclusion, tacrolimus is a safe and effective immunosuppressant in a living related renal transplant program.

Adolescent↗
PubMed2006

Differential response induced by exposure to low-dose ionizing radiation in SHSY-5Y and normal human fibroblast cells.

Radiation therapy has been used in the treatment of a wide variety of cancers for nearly a century and is one of the most effective ways to treat cancer. Low-dose ionizing radiation (IR) can interfere with cell division of cancer and normal cells by introducing oxidative stress and injury to DNA. The differences in the response to IR-induced DNA damage and increased reactive oxygen species between normal human fibroblasts (NHFs) and cancerous SHSY-5Y cells were considered. H2AX staining and comet assays revealed that NHF cells responded by initiating a DNA repair sequence whereas SHSY-5Y cells did not. In addition, NHF cells appeared to quench the oxidative stress induced by IR, and after 24 h no DNA damage was present. SHSY-5Y cells, however, did not repair their DNA, did not quench the oxidative stress, and showed characteristic signs that they were beginning to undergo apoptosis. These results indicate that there is a differential response between this cancerous and normal cell line in their ability to respond to low-dose IR, and these differences need to be exploited in order to treat cancer effectively. Further study is needed in order to elucidate the mechanism by which SHSY-5Y cells undergo apoptosis following radiation and why these normal cells are better equipped to deal with IR-induced double-strand breaks and oxidative stress.

Adenosine Triphosphate↗
PubMed2005

A randomized placebo controlled trial of ranitidine versus sucralfate in patients with spontaneous intracerebral hemorrhage for prevention of gastric hemorrhage.

AIM: Due of paucity of studies on stress ulcer prophylaxis in intracerebral hemorrhage (ICH), we have evaluated the usefulness of ranitidine and sucralfate in preventing gastric hemorrhage (GH) in patients with ICH. SUBJECTS AND METHODS: In a hospital-based randomized placebo-controlled study, patients with CT-proven ICH within 7 days of ictus were randomized into ranitidine 50 mg i.v. eight hourly, sucralfate 1 g six hourly and placebo groups. Patients were conservatively managed. Primary endpoint was occurrence of GH within 15 days of ictus and secondary endpoint 1-month mortality. RESULTS: The mean age of the patients was 57.2 (range 25-90) years and 40 were females. There were 45 patients in ranitidine, 49 in sucralfate and 47 in placebo group. Demographic, clinical and radiological features were not significantly different in 3 groups. GH occurred in 11 (23.4%) patients in placebo, 5 (11.1%) in ranitidine and 7 (14.3%) in sucralfate group, which was not significant. Only one female had GH. There were 13 (27.7%) deaths in placebo, 5 (11.1%) in ranitidine and 12 (24.5%) in sucralfate group. Pneumonia occurred in placebo group in 5 (10.6%), ranitidine in 2 (4.4%) and sucralfate in 5 (10.2%) patients, which was not significantly different. CONCLUSION: Ranitidine and sucralfate do not seem to significantly prevent GH or reduce 1-month mortality.

Adult↗
PubMed2005

Self-assembled Gemini surfactant film-mediated dispersion stability.

The force-distance curves of 12-2-12 and 12-4-12 Gemini quaternary ammonium bromide surfactants on mica and silica surfaces obtained by atomic force microscopy (AFM) were correlated with the structure of the adsorption layer. The critical micelle concentration was measured in the presence or absence of electrolyte. The electrolyte effect (the decrease of CMC) is significantly more pronounced for Gemini than for single-chain surfactants. The maximum compressive force, F(max), of the adsorbed surfactant aggregates was determined. On the mica surface in the presence of 0.1 M NaCl, the Gemini micelles and strong repulsive barrier appear at surfactant concentrations 0.02-0.05 mM, which is significantly lower than that for the single C(12)TAB (5-10 mM). This difference between single and Gemini surfactants can be explained by a stronger adsorption energy of Gemini surfactants. The low concentration of Gemini at which this surfactant forms the strong micellar layer on the solid/solution interface proves that Gemini aggregates (micelles) potentially act as dispersing agent in processes such as chemical mechanical polishing or collector in flotation. The AFM force-distance results obtained for the Gemini surfactants were used along with turbidity measurements to determine how adsorption of Gemini surfactants affects dispersion stability. It has been shown that Gemini (or two-chain) surfactants are more effective dispersing agents, and that in the presence of electrolyte, the silica dispersion stability at pH 4.0 can also be achieved at very low surfactant concentrations ( approximately 0.02 mM).

Journal Article↗
PubMed2005

Modulatory effect of cadmium exposure on deltamethrin-induced oxidative stress in Channa punctata Bloch.

The modulatory effect of cadmium pretreatment (0.2 mg/kg b.w. i.p.) on deltamethrin-induced oxidative stress and alterations of antioxidants was studied in freshwater fish Channa punctata Bloch. Lipid peroxidation (LPO) was measured as one of the indicators of oxidative stress. Activities of glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were also studied in liver, kidney, and gills. Levels of reduced glutathione (GSH) were measured in various tissues. Fish pretreated with cadmium and subsequently exposed to deltamethrin showed significantly reduced LPO values when compared with deltamethrin-exposed fish. Conversely, in the kidney, a potentiation response was observed. Deltamethrin exposure in fish resulted in significant alteration in activities of glutathione-dependent antioxidant enzymes. In the cadmium preexposed fish, which were subsequently exposed to deltamethrin, antioxidant enzymes showed a tendency toward normalization over deltamethrin-only exposed fish in liver and gills. GSH also showed a similar pattern in liver and gills but in kidney it remained elevated. Cadmium alone had no significant effect on various parameters at the concentration used in this study. When metallothionein (MT) induction was studied, only liver showed an MT-like protein band in sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. These results demonstrate a modulatory role of cadmium on the oxidative stress and other related parameters in liver and gills. These findings are important in the context of exposure to a mixture of pollutants in aquatic environment.

Animals↗
PubMed2005

Pancratistatin: a natural anti-cancer compound that targets mitochondria specifically in cancer cells to induce apoptosis.

The major hurdle in the fight against cancer is the non-specific nature of current treatments. The search for specific drugs that are non-cytotoxic to normal cells and can effectively target cancer cells has lead some researchers to investigate the potential anti-cancer activity of natural compounds. Some natural compounds, such as Taxol, have been shown to possess some anti-cancer potential. Pancratistatin (PST) is a natural compound that was isolated from the spider lily Pancratium littorale and shown to exhibit antineoplastic activity. The specificity of PST to cancer cells and the mechanism of PST's action remain unknown. This study provides a detailed look at the effect of PST treatment on cancerous and normal cells. Our results indicate that PST induced apoptosis selectively in cancer cells and that the mitochondria may be the site of action of PST in cancer cells. A biochemical target available specifically in cancer cells may lead to the development of new and more effective cancer fighting agents.

Amaryllidaceae Alkaloids↗
PubMed2005

Cerebrospinal fluid catecholamine levels in Japanese encephalitis patients with movement disorders.

Norepinephrine and dopamine have important role in movement disorders but their role in movement disorders associated with Japanese encephalitis (JE) has not been evaluated. Therefore, in the present study, cerebrospinal fluid (CSF) catecholamine levels and its metabolites in JE patients with movement disorders were compared with those without JE. CSF was collected by lumbar puncture and analyzed by HPLC-ED. Norepinephrine, dopamine and homovanillic acid concentrations were significantly (P<0.005) lower in JE patients compared to control groups. Low levels of catecholamines in JE associated movement disorders compared to idiopathic Parkinson's disease and other extrapyramidal symptoms may be due to severe structural damage to thalamus, basal ganglia and brainstem in JE patients as revealed by MRI findings.

Adolescent↗
PubMed2005

Role of mitochondria in neuronal cell death induced by oxidative stress; neuroprotection by Coenzyme Q10.

Neuronal cells depend on mitochondrial oxidative phosphorylation for most of their energy needs and therefore are at a particular risk for oxidative stress. Mitochondria play an important role in energy production and oxidative stress-induced apoptosis. In the present study, we have demonstrated that external oxidative stress induces mitochondrial dysfunction leading to increased ROS generation and ultimately apoptotic cell death in neuronal cells. Furthermore, we have investigated the role of Coenzyme Q10 as a neuroprotective agent. Coenzyme Q10 is a component of the mitochondrial respiratory chain and a potent anti-oxidant. Our results indicate that total cellular ROS generation was inhibited by Coenzyme Q10. Further, pre-treatment with Coenzyme Q10 maintained mitochondrial membrane potential during oxidative stress and reduced the amount of mitochondrial ROS generation. Our study suggests that water-soluble Coenzyme Q10 acts by stabilizing the mitochondrial membrane when neuronal cells are subjected to oxidative stress. Therefore, Coenzyme Q10 has the potential to be used as a therapeutic intervention for neurodegenerative diseases.

Cell Death↗
PubMed2005

Therapeutic efficacy of antimalarial drugs along the eastern Indo-Nepal border: a cross-border collaborative study.

This collaborative cross-border study was performed to determine the therapeutic efficacy of antimalarial drugs used by the National Programmes for falciparum malaria along the eastern Indo-Nepal border where there is unregulated population movement across the border. The study was conducted at sites in Jhapa District, Nepal and Darjeeling District, India. The study was conducted from August 2003 to February 2004, following the WHO 28 day treatment protocol. The efficacy of chloroquine was tested in India among 91 subjects and of sulfadoxine-pyrimethamine in Nepal among 107 subjects with laboratory-confirmed Plasmodium falciparum malaria. Of the 102 subjects who completed the study in Nepal, there were 21 (20.6%) treatment failures comprising 7 (6.9%) early treatment failures (ETF) and 14 (14.7%) late treatment failures (LTF) (5 late clinical failures [LCF] and 9 late parasitological failures [LPF]). Of the 89 subjects who completed the study in India, there were 46 (51.7%) treatment failures comprising 7 (7.9%) ETFs and 39 (43.8%) LTFs (13 LCFs and 26 LPFs). Based on WHO guidelines both countries need to review their drug policy urgently and make appropriate changes, taking into account aspects of cross-border collaboration in the control of drug-resistant malaria.

Adolescent↗
PubMed2005

Laparoscopic anterior resection and uterine manipulation: why make things difficult?

The uterus continues to be a source of difficulty in mobilization of the rectum. These difficulties are compounded in laparoscopic operations, particularly anterior resection, proctectomy and vaginal sacrocolpopexy. Techniques to overcome this have in general proved unsatisfactory. We have adopted a technique of using an extended Vesellum forceps from gynaecological practice and recommend its use by all. The technique is described.

Colon↗
PubMed2005

Adrenomyeloneuropathy.

Adrenomyeloneuropathy is a rare X-linked inherited disorder of peroxisomes characterized by the accumulation of very long chain fatty acids (VLCFA) in the central and peripheral nervous system, adrenal glands and testis leading to the dysfunction of these organs and systems. The phenotypic expression is highly variable, childhood cerebral adrenoleukodystrophy and adrenomyeloneuropathy being the main variants. Here we report a case of adrenomyeloneuropathy presenting initially as Addison's disease, which remained undiagnosed for many years with many rare features. We could not locate any other publication on this subject in the indexed journals of literature published from India.

Adolescent↗
PubMed2004

Paraquat induces oxidative stress and neuronal cell death; neuroprotection by water-soluble Coenzyme Q10.

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q10 (CoQ10) before paraquat exposure inhibited ROS generation. Pretreatment with CoQ10 also significantly reduced the number of apoptotic cells and DNA fragmentation. We also analyzed the effect of paraquat and CoQ10 on isolated mitochondria. Our results indicated that treatment with paraquat induced the generation of ROS from isolated mitochondria and depolarization of the inner mitochondrial membrane. Pretreatment with CoQ10 was able to inhibit ROS generation from isolated mitochondria as well as the collapse of mitochondrial membrane potential. Our results indicate that water-soluble CoQ10 can prevent oxidative stress and neuronal damage induced by paraquat and therefore, can be used for the prevention and therapy of neurodegenerative diseases caused by environmental toxins.

Apoptosis↗
PubMed2004

A sequential study of visual evoked potential in patients with vitamin B12 deficiency neurological syndrome.

OBJECTIVE: Visual pathways are vulnerable to vitamin B(12) deficiency but there is paucity of studies evaluating visual evoked potential (VEP) changes following vitamin B(12) supplementation. Our aim was to evaluate the visual evoked potential changes in patients with vitamin B(12) deficiency neurological syndrome and their changes after vitamin B(12) therapy. METHODS: Seventeen patients with vitamin B(12) deficiency neurological syndromes diagnosed on the basis of megaloblastic bone marrow or low serum vitamin B(12) level or both were subjected to testing of visual acuity, field of vision, colour vision and neurological examination. Cranial magnetic resonance imaging was done in 9 patients and pattern reversal VEP was carried out on admission. P(100) latency and amplitude were measured. Visual function and VEP studies were repeated at 3 and 6 months after vitamin B(12) therapy. RESULTS: The patients' age ranged between 17 and 69 years; 7 were females and 16 were lactovegetarians. The duration of symptoms ranged between 10 days and 10 years. Visual acuity, colour vision, field of vision and fundus oculi were normal. VEP revealed prolongation of P(100) latency in 10 patients (17 eyes) which was mild in 2, moderate in 10 and marked in 5 eyes. Six months after treatment, P(100) latency improved to normal in all except 4 eyes. VEP abnormality was related to duration of illness and antiparietal cell antibodies. CONCLUSIONS: VEP is frequently prolonged in patients with vitamin B(12) deficiency neurological syndrome although asymptomatic. It usually returns to normal after treatment.

Adolescent↗
PubMed2004

Fly ash leachate induces oxidative stress in freshwater fish Channa punctata (Bloch).

Oxidative stress inducing potential of fly ash leachate (FAL) was studied in a freshwater fish, Channa punctata (Bloch). Fish were exposed to fly ash leachate for 24 h and lipid peroxidation (LPO) was studied as a marker of oxidative stress. Catalase (CAT), glutathione S-transferase (GST) activities and levels of reduced glutathione (GSH) were also estimated in the exposed fish. FAL (1 ml/l) induced LPO in all the organs and most prominent response was in the gill. It also caused induction of enzymes and glutathione. Liver showed highest level of induction of enzyme activities. The results of this study demonstrate that fly ash constituents have potential to induce oxidative stress in fish and gills are the most vulnerable organs. It is also suggested that in case of exposure to FAL, along with LPO antioxidant defense is also activated to counteract the reactive oxygen species (ROS) at least partly in the initial stages of exposure.

Analysis of Variance↗
PubMed2004

Laparoscopic proctocolectomy with restorative ileal-anal pouch.

OBJECTIVE: The aim of the study was to analyse the outcome of restorative proctocolectomy carried out by laparoscopic surgery. METHODS: A prospectively collected electronic database of all colorectal laparoscopic procedures performed between April 2001 and July 2003 has been used to identify surgical outcomes in 14 consecutive patients who have undergone laparoscopic RPC. RESULTS: Fourteen patients (5 male), median BMI 24 kg/m(2) have undergone restorative laparoscopic proctocolectomy over a two year period: 13 (ulcerative colitis, one with cancer) and 1 (FAP). The median operation time was 260 min; time has not decreased with experience. There were no intra-operative surgical complications or deaths. Patient controlled analgesia continued for a median of 36 h. The median time to diet was 48 h and median hospital stay 7 days; three patients required nasogastric aspiration for delayed gastric emptying. Eighteen regional lymph nodes were retrieved local to the carcinoma. There was one anastomotic leak. All covering stomas were closed by 6 months (12 by eight weeks). All 14 patients are fully continent, able to suppress urgency and have a median pouch frequency of 4/24 h. None admit to having problems with potency, orgasm sensation, ejaculation, micturition. One lady reports dysparunia. All are highly satisfied with functional outcome and cosmesis. CONCLUSION: We are encouraged to continue to offer our patients the option of a laparoscopic resection.

Adult↗