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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 1,081 records · Page 60Linked to original sources
PubMedDate not supplied

Two-catheter approach for ablation of accessory pathways in different locations.

Radiofrequency ablation is the treatment of choice for patients with Wolff-Parkinson-White syndrome and symptomatic tachyarrhythmias. The technique involves localising the pathway with multiple catheters at various sites followed by radiofrequency energy application at that site. Single catheter approach has been described for ablation of manifest left-sided accessory pathways. In this article, we report the ablation of accessory pathways in different locations in patients with Wolff-Parkinson-White syndrome by using a two-catheter approach. Twenty-three consecutive patients with symptomatic Wolff-Parkinson-White syndrome were taken up for radiofrequency ablation with this approach. Pathways could be successfully ablated in 11 out of 13 patients with left free wall, 5 out of 7 with right posteroseptal, one patient of left posteroseptal and each of the 2 patients of right mid septal locations giving an overall success in 19/23 (82.6%) patients. Hence, two-catheter approach can be used safely to ablate accessory pathways in different locations with high success rate, thus minimising the procedure time associated with conventional approach.

Adult↗
PubMedDate not supplied

Simultaneous determination of bergenin and gallic acid in Bergenia ligulata wall by high-performance thin-layer chromatography.

A simple and reproducible high-performance thin-layer chromatographic method was developed for the simultaneous determination of bergenin and gallic acid in Bergenia ligulata. Water and methanol were used as the extracting solvents. The concentrations of bergenin and gallic acid in both of these solvents were found to be almost the same. The method involves separation of the components by thin-layer chromatography on a precoated Silica Gel 60 F254 plate with a solvent system of ethyl acetate-formic acid-acetic acid-water (100 + 11 + 11 + 27). The sensitivity of the method for bergenin was 0.30 microg, whereas for gallic acid it was 0.25 microg. The proposed method is precise and sensitive and can be used for the detection, monitoring, and simultaneous quantification of bergenin and gallic acid in B. ligulata.

Anti-Ulcer Agents↗
PubMedDate not supplied

Coronary stent thrombosis: time course and clinical outcome.

The current clinical practice of stent implantation has changed over the last few years. We analysed the incidence and time course of stent thrombosis in patients undergoing successful coronary angioplasty and stenting over the last three years. All the patients were treated with aspirin and ticlopidine. A total of 13 patients experienced stent thrombosis. The mean age was 52+/-12 years; 12 were smokers and 10 had a recent history of myocardial infarction. None of these patients had received abciximab. The median time from stent implantation to stent thrombosis was 10 hours, with all the stent occlusions occurring within 18 hours of stent implantation procedure. All the patients underwent a repeat intervention at a median time of 30 minutes after the clinical suspicion of stent occlusion. On follow-up of 1 to 24 months, three patients developed reocclusion. In the present era of coronary angioplasty and stenting, when interventional procedures are not pre-planned and patients are treated with aspirin and ticlopidine or clopidogrel at the time of stent implantation, the incidence of stent thrombosis is low; it is seen mainly in patients with recent myocardial infarction, majority of them being smokers, and occurs within 18 hours in all the patients.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Coronary stent implantation without lesion predilatation (direct stenting): our experience with this evolving technique.

BACKGROUND: Until recently, conventional intracoronary stent deployment required predilatation of the lesion with a balloon. However, "direct stenting" of the lesion without predilatation offers certain theoretical and practical advantages. We assessed the safety and feasibility of direct stenting in a select group of patients who were likely to benefit most from these advantages, namely, those with acute coronary syndromes. saphenous vein graft lesions, associated renal or left ventricular dysfunction and those requiring multivessel intervention. METHODS AND RESULTS: After direct stenting, intravascular ultrasound was used to assess the adequacy of stent expansion in 51 patients. One hundred and twenty patients with a total of 125 lesions (83.3% males, average age 54.6+/-12.4 years) were enrolled for direct stenting. Of these, 90% of patients had presented with acute coronary syndromes, 21.6% of patients had associated moderate-to-severe left ventricular systolic dysfunction, 6.7% of patients had associated renal dysfunction and 30.8% of patients required multivessel intervention. Angiographically visible thrombus was present in 35.2% of patients. The mean reference diameter of the lesion was 3.18+/-0.32 mm and mean percentage diameter stenosis was 76.4+/-11.2%. Almost all varieties of stents were used (8.8% bare and 91.2% mounted). Procedural success was achieved in 98.3% of patients (98.4% of lesions). In two cases, the lesion had to be predilated prior to stenting. On angiography, the need for postdilatation of the stent was apparent in 29 (23.6%) lesions. In contrast, on intravascular ultrasound evaluation done in 51 lesions after stent deployment, the need for postdilatation to optimize stent expansion was seen in 43 (84.3%) lesions. There was one instance of acute stent thrombosis and two instances of slow-flow phenomenon. There were no deaths, myocardial infarction or need for urgent bypass surgery. CONCLUSIONS: We conclude that direct stenting is feasible and safe in selected groups of patients. Optimization of stent expansion after direct stenting may often require aggressive postdilatation.

Coronary Disease↗
PubMedDate not supplied

Cementoblastoma associated with a primary tooth: a rare pediatric lesion.

An intraosseous, slightly painful swelling was noted upon clinical examination of an eight-year-old girl. The swelling was of an unspecified duration and slow growing in nature. A radiopaque mass with a radiolucent periphery attached to the roots of the mandibular right second primary molar was noted on a periapical radiograph. The diagnosis of cementoblastoma was verified by the histologic assessment.

Biopsy↗
PubMedDate not supplied

Chemopreventive effects of green tea polyphenols correlate with reversible induction of p57 expression.

Green tea polyphenols are known to induce apoptosis in certain types of tumor cells. However, the mechanism(s) that enables normal cells to evade the apoptotic effect is still not understood. In this study, Western blot analysis combined with cycloheximide treatment was used to examine the effects of green tea polyphenols on the expression levels of p57, a cyclin-dependent kinase and apoptosis inhibitor, in normal human keratinocytes and in the oral carcinoma cell lines SCC25 and OSC2. The results showed that the most potent green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), induced p57 in normal keratinocytes in a dosage- and time-dependent manner, while the levels of p57 protein in oral carcinoma cells were unaltered. The differential response in p57 induction was consistent with the apoptosis status detected by annexin V assay. The data suggest that the chemopreventive effects of green tea polyphenols may involve p57-mediated cell cycle regulation in normal epithelial cells.

Aged↗
PubMedDate not supplied

Fulminant amoebic colitis: a favorable outcome.

Fulminant amoebic colitis (FAC) is often associated with a poor outcome (reported mortality between 55% and 87.5%). We present the outcome of a conservative surgical approach to the management of this condition. Over an 8-year period (January 1992 to December 1999), 23 patients with FAC were managed and prospectively evaluated by a surgical unit at King Edward VIII Hospital, Durban. There were 19 males and 4 females with a mean age of 36 years (range, 18-57 years). Unrelenting abdominal signs was the indication for surgery in all patients. A preoperative diagnosis of FAC was made in 20 patients; in 1 patient the diagnosis was made intraoperatively. FAC was not recognized in 2 patients. The 21 patients diagnosed with FAC were managed by perileal antegrade colonic lavage; 2 patients underwent total colectomy and ileostomy. Following colonic lavage and ileostomy, there was a 95% survival rate (N = 20). Both patients who underwent total colectomy and ileostomy died postoperatively. Patients underwent restorative surgery at a mean period of 7.2 weeks (range, 6-10 weeks) following the initial surgery. The extent of colonic stricturing invariably warranted colonic resection. This included total colectomy (N = 12), right hemicolectomy (N = 5), left hemicolectomy (N = 2), and right and transverse colectomy (N = 1). The overall survival rate of the 23 patients presenting with FAC was 82.6% (N = 19). Early recognition of FAC and a conservative surgical approach are associated with a favorable outcome. Resectional surgery in FAC has a potentially fatal outcome and should be avoided.

Adult↗
PubMedDate not supplied

Catheter ablation of retrograde fast pathway in patients with atrioventricular nodal reentrant supraventricular tachycardia.

Atrioventricular (AV) nodal reentrant tachycardia is a common cause of supraventricular tachycardia. The present study describes catheter ablation of this form of tachycardia in 23 patients using direct current shocks. The aim of ablation was to abolish conduction through the retrograde pathway while preserving the anterograde conduction. All patients had symptomatic, drug resistant, slow-fast variety of dual atrioventricular nodal reentrant tachycardia. Using the retrograde atrial activation in the His bundle catheter as the reference, the optimal ablation site was selected by positioning an electrode catheter to obtain atrial activation synchronous with or earlier than the atrial activation at the reference electrode. Shocks of 100-300 joules were delivered at this site resulting in blockade of retrograde conduction in all patients. Ventriculo-atrial conduction studied 24 hours after the procedure was still absent in 16, modified in 2 and resumed in 3 patients. Two patients developed permanent complete heart block and were given pacemakers. At repeat electrophysiologic study performed after 2-4 months in 10 patients, the supraventricular tachycardia could not be induced. The AH interval was 67 +/- 10 msec during control study and to 115 +/- 39 msec at restudy (p < 0.001). The ventriculo-atrial conduction was absent in 7 cases and had been modified in 1 case. Over a follow up period of 1-30 months (mean 10.8 +/- 7.1 mo) 17 patients (73%) remained free of the arrhythmia without medication or pacemaker. Three other patients were easily controlled with digoxin. Thus, catheter modification of AV node results in permanent cure of the AV nodal tachycardia in majority of patients.

Adolescent↗
PubMedDate not supplied

Trends of acute poisoning in south Karnataka.

BACKGROUND: In recent times poisoning with agricultural chemicals either accidental or suicidal has become common due to easy availability and low cost. So it has become essential to find out the burden of poisoning to the victims, family and to hospital and morbidity and mortality among the victims. AIMS: To determine the trends of poisoning along with various parameters such as mode of poisoning, type of poison used, outcome of the poisoning, the most vulnerable age group, occupation of the victim, and the marital status. METHOD: A 5 year retrospective study in which all the patients of acute poisoning admitted to Govt. Wenlock Hospital, Mangalore during the period from 1st Jan 1999 to 31st December 2003 were included. A total of 546 cases were admitted due to acute poisoning during the study period. RESULTS: Three hundred and eighty (69.6%) males and one hundred and sixty six (30.4%) females were admitted to the hospital due to poisoning. Organophosphates were the most commonly used suicidal poison irrespective of age, sex and occupation of the victim. There were two hundred and thirty five cases of male suicidal poisoning and one hundred and twenty six female cases of suicidal poisoning. Majority of poisoning cases were seen in manual labourers. The increasing trend of poisoning was observed for the period of 1999 to 2003 except for the year of 2003. CONCLUSION: The study highlights about the problem of poisoning in the region. Since the majority of the victims of the poisoning are from low socio economic status. There is economic burden on the family members of the victim of poisoning as the earning member of the family becomes ill (for treatment), dies (loss of earning member) and also emotional setback and disturbance.

Adult↗
PubMedDate not supplied

Clinical utility of transoesophageal echocardiography--preliminary experience of 100 cases.

We performed transoesophageal echocardiography (TEE) and compared its results with transthoracic echocardiographic (TTE) studies in a consecutive series of 100 cases. TEE was performed with a 5 MHz transducer with pulsed wave, continuous wave and colour Doppler facilities. All the patients were in unsedated state; the initial 50 were, in addition, monitored noninvasively for any change in heart rate, blood pressure or arterial oxygen saturation. The procedure was well tolerated by all; one patient had transient ventricular bigeminy. Except increase in heart rate and systolic blood pressure at the time of insertion of probe, there was no change in any of the clinical parameters studied. In patients of mitral stenosis, a thrombus in left atrium (LA) or left atrial appendage (LAA) was seen in 7/52 TEE studies, as compared to 4/52 TTE studies. LAA thrombi (2 cases) were detected only on TEE. Following balloon mitral valvuloplasty, a small atrial septal defect was seen in 6/8 TEE, but only 2/8 TTE studies. In 20 cases with doubtful atrial septal defects on TTE, TEE revealed an intact septum in 6 and delineated the anatomy of the defect in the remaining 14. TEE facilitated detection and better visualisation of paravalvular regurgitation in 4 cases with mitral and 3 cases with aortic valve prosthesis. In addition, TEE helped in excluding vegetations in 3 suspected cases of infective endocarditis and in studying details of 2 intracardiac masses. We conclude, TEE can be safely performed in conscious unsedated patients and provides valuable information in addition to transthoracic echocardiography.

Adult↗
PubMedDate not supplied

Verapamil responsive ventricular tachycardia: clinical and electrophysiologic characteristics.

Ventricular tachycardia is a rare arrhythmia in young patients without associated heart disease. Electrophysiologic studies were performed in thirteen young patients (mean age 26.4 +/- 7 years) with recurrent sustained ventricular tachycardia (VT) responsive to intravenous verapamil. The QRS duration during VT was less than 0.14 sec in all patients. The VT showed a right bundle branch block (RBBB) morphology in all cases, with left axis deviation in 12 and right axis deviation in one. Eleven patients were free of organic heart disease. VT could be induced in the laboratory in 10 patients, out of whom the electrophysiologic mechanism of VT could be assessed in 9 cases. The data were consistent with reentry in 8 patients and suggested triggered activity in one patient. Atrial pacing induced the VT in two cases. Nine patients were restudied 48 to 72 hours after oral verapamil (240 to 320 mg/day). VT was not inducible in 8 patients and was markedly slowed in one. VT of RBBB morphology occurring in young patients has distinct electrocardiographic and electropharmacologic properties. Reentry is the usual underlying mechanism. Verapamil is highly effective in terminating and preventing the VT.

Adolescent↗