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Biomedical subjects

S Singh

Publications and source records attributed to S Singh.

At least 181 records · Page 10Linked to original sources
PubMed2002

Role of self-expandable metal stents in the palliation of malignant duodenal obstruction.

BACKGROUND: Palliative surgical intervention for malignant duodenal obstruction is often associated with a significant morbidity. Endoscopic enteral stenting offers a suitable alternative, that is safe, effective, and less invasive. This study reports our experience with the use of self-expanding metal stents in the palliation of malignant gastric duodenal obstruction. METHODS: A retrospective review of all patients who underwent duodenal stenting from November 1998 to February 2001 was performed. All the patients had symptomatic gastric outlet and duodenal obstruction with nausea, vomiting, and decreased oral intake. All of them underwent enteral stenting with self-expandable metal Wallstents 20 or 22 mm in diameter and 6 or 9 cm long. RESULTS: For this study, 33 patients (19 men and 14 women) with a mean age of 62 years (range, 37-81 years) were identified, 32 of whom had successful duodenal stent placement (6 were performed as outpatient surgery). The malignancies were pancreatic 18 (54%), gastric 4 (12%), duodenal 3 (9%), metastatic 6 (18%), and cholangiocarcinoma 2 (6%) disorders. The site of obstruction was pyloric (n = 5; 15%), pyloroduodenal (n = 3; 9%), duodenal bulb (n = 11; 33%), second portion of duodenum (n = 9; 27%), second and third portion of duodenum (n = 3; 9%), C-loop (n = 1; 3%), and anastomotic (n = 1; 3%). A total of 29 patients (91%) had good clinical outcomes, with relief of obstructive symptoms, Two of three patients with no symptomatic relief underwent gastrojejunostomy. One patient refused further treatment. No immediate stent-related complications were noted. During the follow-up period, 20 patients died (none as a result stent-related causes) due to progression of cancer. Median survival was 102 days. Four patients had recurrent obstruction (2 tumor ingrowths, 1 overgrowth, and 1 distally migrated stent) at a mean interval of 82 days. All four had successful restenting without complications. CONCLUSION: Self-expandable metal stents placed endoscopically provide a safe, less invasive palliative treatment option with good clinical outcome in the management of malignant gastric outlet-duodenal obstruction.

Adult↗
PubMed2002

Clinical outcome of simultaneous self-expandable metal stents for palliation of malignant biliary and duodenal obstruction.

BACKGROUND: Previous studies have shown that self-expanding metal stents are an effective method for palliation of malignant biliary or duodenal obstruction. We present our experience with the use of simultaneous self-expandable metal stents for palliation of malignant biliary and duodenal obstruction. METHODS: We performed a retrospective review of all patients undergoing simultaneous biliary and duodenal self-expandable metal stent placement between November 98 and May 2001. All the patients had documented evidence of biliary obstruction and symptomatic duodenal obstruction. The patients received endoscopic biliary stenting with biliary Ultraflex or Wallstents, and endoscopic duodenal stenting using enteral Wallstents. They were followed until their death. RESULTS: We identified 18 patients (11 men and 7 women) whose mean age was 65 years, (range, 46-85 years). Malignancies included pancreatic 14 (78%), biliary 2 (11%), lymphoma 1 (5%), and metastatic 1 (5%) disorders. Ten patients previously had plastic biliary stents placed for past malignant biliary obstruction (4 patients had recurrent biliary obstruction). All the patients had evidence of duodenal obstruction. Combined metal stenting was successful in 17 patients. One procedure failed due to a tortuous duodenal stricture. All the patients had effective palliation of biliary obstruction, as evidenced by a decrease in the level of total bilirubin and alkaline phosphatase. Of the 17 patients with successful duodenal stenting, 16 had a good clinical outcome, with relief of obstructive symptoms. No immediate stent-related complications were noted. During the follow-up period, 12 patients died of progression of the underlying malignancy. None of the deaths were stent related. Median survival time was 78 days. Two patients had recurrent biliary obstruction from tumor ingrowth at 45 and 68 days, respectively. Both underwent restenting: one by endoscopic retrograde cholangiopancreatography (ERCP) and the other by percutaneous transhepatic cholangiography (PTC). Two other patients had recurrent duodenal obstruction, respectively, 36 and 45 days after the initial stenting. One obstruction was secondary to tumor ingrowth, and the other was caused by distal stent migration. Both patients had successful duodenal restenting. CONCLUSION: Combined self-expandable metal stenting for simultaneous palliation of malignant biliary and duodenal obstruction may provide a safe and less invasive alternative to surgical palliation with an acceptable clinical outcome. Simultaneous self-expandable metal stents should be considered as a treatment option for patients who are poor candidates for surgery.

Aged↗
PubMed2002

Posterior atlantoaxial dislocation without associated fracture.

We report on a 38-year-old man with post-traumatic posterior displacement of the atlas with respect to the axis without any associated fracture or neurological deficit caused by the displacement. Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) revealed posterior displacement of the atlas with the odontoid peg lying anterior and to the right of the anterior arch of the atlas.

Accidents, Traffic↗
PubMed2002

Confirmation of association between D10S583 and Alzheimer's disease in a case--control sample.

Several independent studies have reported that loci on chromosome 10 are associated/linked with Alzheimer's disease (AD), including a family-based study demonstrating an association between the marker D10S583 and AD. We have examined the D10S583 polymorphic marker and apolipoprotein E (APOE) gene in a case-control study. We observed the expected association of the APOE allele varepsilon4 with AD, and an inverse association between the D10S583 allele 209 and AD. These data support the original findings that suggest the presence of a candidate gene for AD in this region of chromosome 10. The nearby insulin degrading enzyme gene has been previously proposed as a candidate gene; however, a number of other putative candidate genes are also located in this region. The ongoing investigation of the genetic source of association and linkage in this region is clearly warranted.

Aged↗
PubMed2002

APOE genotype influences acquisition and recall following traumatic brain injury.

APOE has been demonstrated to influence traumatic brain injury (TBI) outcome. The relationship between APOE genotype and memory following TBI was examined in 110 participants in the Defense and Veterans' Head Injury Program. Memory performance was worse in those who had an APOE epsilon 4 allele (n = 30) than those who did not (n = 80), whereas genotype groups did not differ on demographic or injury variables or on measures of executive functioning. These data support a specific role for the APOE protein in memory outcome following TBI, and suggest an APOE isoform-specific effect on neuronal repair processes.

Adult↗
PubMed2002

Effect of a carbohydrate supplement on feeding behaviour and exercise in rats exposed to hypobaric hypoxia.

The effect of a carbohydrate supplement, offered as a diet option, on feeding behaviour, body weight gain, and endurance exercise was studied in rats exposed to hypobaric hypoxia. Male albino rats (n = 35) were randomly divided into 5 groups; hypoxic supplemented and control groups; normoxic supplemented and control groups, and an untreated control group. After treadmill training for 5 days, the hypoxic groups were exposed to simulated high altitude equivalent to 6960 m for 18 days continuously. Food and water intakes, body weight and endurance exercise were recorded before and during the exposure period. Blood glucose, insulin, muscle and liver glycogen were assayed at the end of the exposure period. Hypobaric hypoxia resulted in a significant decrease in food and water intake, and body weight, and reduced endurance exercise capacity compared to the basal and normoxic group values. The carbohydrate supplement did not ameliorate the hypoxia-induced loss in body weight, but however, significantly delayed the onset of fatigue during exercise in the supplemented rats compared to the hypoxic control group.

Altitude↗
PubMed2002

Reversal of lead-induced oxidative stress by chelating agent, antioxidant, or their combination in the rat.

The influence of N-acetyl cysteine (NAC), an antioxidant, on the therapeutic efficacy of meso-2,3-dimercaptosuccinic acid (DMSA), a hydrophilic, and its ester, monoisoamyl 2,3-dimercaptosuccinate (MiADMS), a lipophilic, both soft tissue lead mobilizers, was investigated in lead-preexposed rats. The subsequent treatment of lead-exposed animals with DMSA, MiADMS, or NAC reversed the lead-induced alterations in blood delta-aminolevulinic acid dehydratase, catalase, malondialdehyde (MDA), reduced glutathione, oxidized glutathione, and brain MDA levels. The combined treatment with DMSA and NAC was more effective than that with MiADMS and NAC in enhancing the restoration of all these parameters indicative of lead-induced oxidative stress. These reversals were consistent with the lead-removing ability of DMSA and MiADMS but not that of NAC. As the reversal of these parameters by NAC was independent of its lead-mobilizing capability, this ought to be mainly due to its strong antioxidant property. The increase in blood and brain zinc levels upon lead exposure appears to be the result of the redistribution of endogenous zinc due to lead. Subsequent treatment with DMSA, MiADMS, NAC, or their combination decreased the brain zinc as its excretable complexes with a transient increase in blood zinc level. The ideal treatment of lead poisoning seems to be a combination of a lead chelator and an antioxidant.

Acetylcysteine↗
PubMed2002

Disabling pansclerotic morphea of childhood and hypogammaglobulinemia: a curious association.

This communication describes a 1.5-year-old girl who presented with multiple episodes of infection since early infancy and stiffening of limbs for 2 months. Biopsy of the involved areas showed features consistent with pansclerotic morphea. Immunoglobulin estimation revealed hypogammaglobulinemia. This unique combination of pansclerotic morphea with hypogammaglobulinemia has not been reported before.

Agammaglobulinemia↗
PubMed2002

Mortality patterns in childhood lupus--10 years' experience in a developing country.

Over the last 10 years we have seen 31 children with systemic lupus: 10 (32%) of these have died. The commonest primary determinant of mortality was uncontrolled disease activity (60%), possibly contributed to by late referrals leading to delays in diagnosis and the institution of therapy. Thromboembolic disease was responsible for two deaths and tuberculosis for one. The major contributory factors were nephritis in two patients and myocarditis, endocarditis, lupus pneumonia and CNS disease in one patient each. Concomitant infections, predominantly nosocomial, occurred in a significant proportion of patients (40%) but were only cofactors in mortality. Autopsies were done in three cases. These patterns of death are significantly different from those seen in the developed world, where disease activity has ceased to be an important factor owing to early recognition of cases. Avoiding late referrals and delays in diagnosis can reduce mortality in childhood-onset lupus.

Cause of Death↗
PubMed2002

Proton MR spectroscopy of basal ganglia in Wilson's disease: case report and review of literature.

Volume localized proton Magnetic Resonance Spectroscopy was carried out in both the left and right basal ganglia of three patients with clinically proven Wilson's Disease. While the untreated patient died 15 days after the spectroscopy study, the other 2 patients have been under treatment and have shown clinical improvement. The spectral features of the untreated patient were very different from those of the other two patients who were under treatment and responding. Asymmetrical changes in NAA and Cho were also observed for this patient.

Adolescent↗
PubMed2002

Amylase hyperproduction by deregulated mutants of the thermophilic fungus Thermomyces lanuginosus.

Thermomyces lanuginosus was subjected to three cycles of mutagenesis (UV/NTG) and a selection procedure to develop amylase-hyperproducing, catabolite-repression-resistant and partially constitutive strains. One of the selected derepressed mutant strain III(51), produced approximately 7- and 3-fold higher specific activity of alpha-amylase (190 U/mg protein) and glucoamylase (105 U/mg protein), respectively, compared to a wild-type parental strain. Further, the effect of production parameters on mutant strain III(51) was studied using a Box-Behnken design. The regression models computed showed significantly high R(2) values of 96 and 97% for alpha-amylase and glucoamylase activities, respectively, indicating that they are appropriate for predicting relationships between corn flour, soybean meal and pH with alpha-amylase and glucoamylase production.

Amylases↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed2002

Sulphide-induced energy deficiency in colonic cells is prevented by glucose but not by butyrate.

BACKGROUND: In ulcerative colitis, hydrogen sulphide is postulated to impair colonocyte butyrate metabolism, leading to cellular energy deficiency and dysfunction. AIMS: To determine the effects of sulphide exposure on butyrate metabolism and adenosine triphosphate levels of HT29 colonic epithelial cancer cells, and to establish whether energy deficiency can be prevented by increased butyrate concentrations or the presence of glucose. METHODS: HT29 cells were maintained in medium containing 3 mM butyrate, 5 mM glucose, or both substrates. Oxidation rates were measured by 14CO2 release from 14C-labelled substrates. Cellular adenosine triphosphate was assayed using the luciferin/luciferase chemiluminescent method. The effects of sulphide (0-5 mM) on substrate oxidation and adenosine triphosphate levels and of increasing butyrate concentration (0-30 mM) with sulphide were observed. RESULTS: HT29 cells showed similar energy substrate usage to primary colonocyte cultures. Sulphide exposure inhibited butyrate oxidation and led to a reduction in cellular adenosine triphosphate. This fall was prevented by co-incubation with glucose, but not by increasing concentrations of butyrate. CONCLUSIONS: HT29 cells utilize butyrate as an energy substrate and represent a useful in vitro model of the effects of sulphide on colonocytes. Sulphide inhibits butyrate oxidation and leads to demonstrable energy deficiency, prevented by the presence of glucose but not by increased butyrate concentrations.

Butyrates↗