PubMed Health⌕ Search

Biomedical subjects

S N Sinha

Publications and source records attributed to S N Sinha.

At least 19 recordsLinked to original sources
PubMed2006

Dose reduction to normal tissues as compared to the gross tumor by using intensity modulated radiotherapy in thoracic malignancies.

BACKGROUND AND PURPOSE: Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities.The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies. MATERIALS AND METHODS: During the period January 2002 to March 2004, 12 patients of various sites of malignancies in the thoracic region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms. RESULTS: An average dose reduction of the mean values by 73% to the heart, 69% to the right lung and 74% to the left lung, with respect to the GTV could be achieved with IMRT.The 2 year disease free survival was 59% and 2 year overall survival was 59%. The average number of IMRT fields used was 6. CONCLUSION: IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

Adult↗
PubMed2006

Can dose reduction to one parotid gland prevent xerostomia?--A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy.

AIMS: Dryness of the mouth is one of the most distressing chronic toxicities of radiation therapy in head and neck cancers. In this study, parotid function was assessed in patients with locally advanced head and neck cancers undergoing intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Parotid function was assessed with the help of a questionnaire and parotid scintigraphy, especially with regards to unilateral sparing of the parotid gland. MATERIALS AND METHODS: In total, 19 patients were treated with compensator-based IMRT between February 2003 and March 2004. The dose to the clinical target volume ranged between 66 and 70 Gy in 30-35 fractions to 95% of the isodose volume. Ipsilateral high-risk neck nodes received an average dose of 60 Gy and the contralateral low-risk neck received a dose of 54-56 Gy. Eight of 19 patients also received concomitant chemotherapy. RESULTS: Subjective toxicity to the parotid glands was assessed with the help of a questionnaire at 0, 3 and 6 months and objective toxicity was assessed with parotid scintigraphy at 0 and 3 months. The mean dose to the ipsilateral parotid gland ranged from 19.5 to 52.8 Gy (mean 33.14 Gy) and the mean dose to the contralateral gland was 11.1-46.6 Gy (mean 26.85 Gy). At a median follow-up of 13 months, 9/19 patients had no symptoms of dryness of the mouth (grade I), 8/19 had mild dryness of the mouth (grade II) and only 2/19 had grade III xerostomia, although the parotid gland could only be spared on one side in most of the patients. CONCLUSIONS: Minimising the radiation dose to one of the parotid glands with the help of IMRT in patients with advanced head and neck cancers can prevent xerostomia in most patients and parotid scintigraphy is a useful method of documenting xerostomia.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Upregulation of inducible nitric oxide synthase (iNOS) expression in faster-healing chronic leg ulcers.

OBJECTIVE: Chronic leg ulcers represent a growing clinical problem in the light of today's ageing population. Nitric oxide (NO), which is mostly produced by inducible nitric oxide synthase (iNOS) in healing wounds, exerts beneficial effects on many processes of healing, including bactericidal effects, angiogenesis, epithelialisation and ECM formation. This study sought to investigate whether iNOS expression in chronic leg ulcers can be correlated with the healing process. METHOD: Sixteen patients with chronic leg ulcers were recruited and attempts were made to take punch biopsies at two separate time points (however, a second biopsy could not be obtained on seven patients). A linear healing rate was derived using the obtained ulcer area and perimeter. The iNOS levels in the biopsy samples were assessed using immunoblotting. RESULTS: The mean linear healing rate of patients with high iNOS levels was significantly higher (p < 0.01) than that of patients with low iNOS levels. An incidental finding was that the linear healing rate was significantly higher (p < 0.05) post-biopsy than before biopsy in the same patients. CONCLUSION: This study therefore shows for the first time that high iNOS levels are associated with higher healing rates and have the potential to be used in prognostication. This also opens the possibility of augmentation of ulcer healing through the manipulation of wound NO levels.

Aged↗
PubMed2005

A correlation of secondary aerosol (nitrate and sulfate) with respirable particulate matter (RPM) in ambient air at different traffic junctions of Vadodara city.

The correlation study of secondary aerosol (nitrate and sulfate) with RPM in ambient air at different traffic junctions of Vadodara city is reported. RPM was analyzed using Ion Chromatography technique and measured the level of nitrate and sulfate in ambient air. The correlation studies of these particulates with RPM have been established. The average concentration of sulfate and nitrate in ambient air was found 35.74 microg/m3 and 24.22 microg/m3, which ranged of 5.33-84.69 and 1.93-77.86 microg/m3 respectively. The correlation of RPM and SO4 (r = 0.813, P<0.01), RPM-NO3 (r = 0.5549, P<0.01) and SO4-NO3 (r = 0.6133, P<0.01) were found significant. The presence of sulfate and nitrate in RPM is 8.25% and 5.60% . The pH of water extract of RPM averaged 6.81, which ranged 6.17-7.28. Regression analysis result showed that the relationship between RPM-SO4 was significantly (R2=0.66215) correlated. This indicate that probably the secondary aerosols such as nitrate and sulfate in excess may cause irritation and increasing lung disease.

Aerosols↗
PubMed2004

Mesh plug repair for paraumbilical hernia.

BACKGROUND: The standard method of repair of paraumbilical hernia (PUH) is by the Mayo technique, using a double-breasted flap of the rectus sheath. The reproducibility of this technique in the hands of others is highly variable. The present study describes and evaluates the application of a Prolene mesh plug in the repair of PUH. The use of a mesh plug in hernia repair is not a new concept with previous investigators yielding consistently excellent results in the repair of femoral and inguinal hernias. METHODS: The study is a retrospective analysis of hospital records and telephone interviews of 34 patients having undergone PUH repair using the mesh plug technique in the period March 1998- May 2002. There were 20 males and 14 females with a median age of 53 years (range 34-86 years). Seventy-six percent (26) of the patient sample was obese (median BMI 33). Whenever possible local anaesthetic was used. Principal outcome measures studied were post-operative complications, recurrences, length of stay in hospital, post-operative analgesia, duration of drain, return to normal activities and patient satisfaction. RESULTS: Post-operative complications encountered included one case of seroma and a single wound infection with recurrence. Ninety-seven percent (32) of patients were satisfied with the procedure. CONCLUSION: Mesh plug repair can be performed with minimal postoperative complications, low recurrence rate, minimal post-operative pain and achieving excellent patient satisfaction. Prosthetic mesh plug repair under local anaesthetic could become the standard treatment for PUH in adults.

Adult↗
PubMed2004

Erosion of nails following thallium poisoning: a case report.

This case report describes a patient with thallium poisoning caused by repeated exposure to low doses of thallium. Alopecia and nail changes were the most prominent features of this case. There was dystrophy of nails in the form of whitish lunular stripes. This is the first report of complete erosion of proximal parts of nails following thallium poisoning. This case is the first report of thallium poisoning from India occurring from repeated low dose exposure.

Adult↗
PubMed2000

Refractory amiodarone-associated thyrotoxicosis: an indication for thyroidectomy.

BACKGROUND: Tasmania is an area of endemic iodine deficiency. Amiodarone is a class III anti-arrhythmic drug that is widely used for the management of ventricular and supraventricular tachydysrhythmias. Individuals from areas of endemic iodine deficiency appear more likely to manifest hyperthyroidism following amiodarone therapy, whereas hypothyroidism is a more frequent complication in iodine-replete communities. METHODS: Cases series. The clinical and biochemical response to medical and surgical management of five consecutive Tasmanian patients presenting with severe type-II amiodarone-associated thyrotoxicosis was reviewed. RESULTS: Five patients were identified. Combinations of antithyroid therapy including propylthiouracil, lithium carbonate, dexamethasone and cholestyramine were used. Thyroidectomy was required in two cases (40%) due to severe unremitting thyrotoxicosis despite combined drug regimens. Anaesthesia and total thyroidectomy were undertaken without complication despite the presence of severe hyperthyroidism at the time of surgery. In both cases thyroid histopathology demonstrated degenerative and destructive follicular lesions with multinuclear cell infiltrate and focal fibrosis. CONCLUSION: Amiodarone-associated thyrotoxicosis may be severe and refractory to medical therapy. Despite the potential risks of anaesthesia associated with uncontrolled thyrotoxicosis, thyroidectomy should be considered in the setting of life-threatening thyrotoxicosis.

Acute Disease↗
PubMed2000

Do leg ulcer clinics improve patients' quality of life?

The aim of this prospective study was to measure quality of life in patients with chronic leg ulcers. All eligible, consenting patients who attended the leg ulcer clinic at the Repatriation General Hospital (Tasmania, Australia) during the 16-month study period were included. Patients completed questionnaires on their first visit and at follow-up which occurred, on average, eight weeks later. This study found an improvement in three quality-of-life indicators--pain, sleep and mobility--over an average of eight weeks' treatment involving one to three visits to the clinic and home visits by primary care nurses. Of the 57 patients, 53 (93%) indicated that their wound had improved following attendance at the clinic. The cost-effectiveness of providing treatment in a dedicated leg ulcer clinic has been the focus of many previous studies. This study emphasises the additional benefits a dedicated clinic may have in improving quality of life in patients with chronic leg ulcers. Such benefits ought to be considered when allocating resources to leg ulcer services.

Adult↗
PubMed1998

Chromatographic studies on the isolation of peroxydisulphate oxidation products of primaquine.

Eight compounds from peroxydisulphate oxidation of primaquine were fractionated on Bio-Gel P-2 column using water as an eluent. A HPLC method employing acetonitrile-methanol-1 M perchloric acid-water (30:7:1:95, v/v) as a mobile phase at 1.0 ml/min on microBondapak reversed-phase column and UV detection at 254 nm was developed for the separation and identification of different oxidation products of primaquine. A combination of Bio-Gel chromatography with reversed-phase HPLC was found to be the most suitable analytical technique for the semipreparative isolation of various products formed from the oxidation. Two oxidation products that were isolated had three or four times higher gametocytocidal activity as compared to primaquine.

Antimalarials↗
PubMed1996

Initial parathyroid exploration: current trends in Australia.

BACKGROUND: An Australia-wide multicentre prospective study was undertaken to audit cases of initial parathyroid exploration between 1 January and 31 December 1992. One hundred and sixty-two cases were audited. The audit was designed to study pre-operative biochemical assessment, localization techniques and the technique of exploration. METHOD: A pro forma audit form was circulated to all Australian surgeons known to perform parathyroid surgery. Eleven responded. RESULTS: Free serum ionized calcium (iCa) was measured in 30% of cases, with the majority of pre-operative calcium assays being performed using total serum calcium (tCa). In 40 cases (29%) pre-operative localization techniques were used. These proved inaccurate in 10 cases. The intra-operative technique of localization with methylene blue infusion was used in 11% of cases. All four glands were biopsied in 11% of cases. No deaths were reported and a postoperative morbidity rate of 3.1% was noted. Eighty-eight per cent of patients were discharged within 5 days of surgery with a third going home within 48 h of neck exploration surgery. Only one patient (0.6%) required re-exploration for persistent hypercalcaemia due to a second adenoma. CONCLUSIONS: The surgical treatment of hyperparathyroidism can be regarded as safe, with minimum morbidity in experienced hands. Pre-operative localization studies in initial parathyroid exploration are not indicated.

Adolescent↗
PubMed1996

Burns admissions to Port Moresby General Hospital 1978-1984.

A retrospective survey of 169 burns cases admitted to Port Moresby General Hospital was conducted for the period 1978 to 1984. A third of the patients were young children. Hot-water burns were the commonest type of injury, accounting for 43%. This was followed by accidental falls into a fire and suicidal kerosene burns, which accounted for 28% and 13% respectively. Post-burn contractures were the commonest long-term complications. Prevention of burns is theoretically very attractive but hard to achieve in rural and squatter populations who rely almost entirely on open fires for cooking and heating. Burns awareness campaigns by all government and community groups stressing the dangers of open fires and leaving children unattended would no doubt take a long time but might ultimately produce tangible results.

Adolescent↗
PubMed1995

Immunohistochemical detection of p53 and the recurrence of rectal adenocarcinoma.

The relationship between immunohistochemical detection of the p53 tumour-suppressor gene and recurrence of disease in 66 cases of rectal adenocarcinoma treated at the Royal Hobart Hospital, Hobart, Tasmania, between 1984 and 1992 was investigated. Fifty-five per cent (n = 36) of patients demonstrated p53 nuclear immunoreactivity consistent with the presence of the stabilized protein derivative of a mutation at the p53 gene locus. No correlation between p53 immunoreactivity and tumour site, differentiation and stage was noted. An overall recurrence rate of 64% (n = 42) was noted. Multivariate analysis confirmed the absence of p53 immunoreactivity and anatomical site of tumour below 7 cm from the anal verge to be significant predictors of tumour recurrence (P < 0.001). A review of the current literature on p53 suggests caution in using the immunohistochemical detection of p53 to predict the clinical outcome in cases of rectal adenocarcinoma because of discordant results between studies.

Adenocarcinoma↗
PubMed1995

Review of liver trauma management in Tasmania: an analysis of risk factors for mortality and morbidity.

A review of liver trauma treated by the major trauma care facilities of Tasmania in the 5 year period between 1989 and 1993 is presented. The aim of this retrospective review was to provide an audit of the management of liver trauma in the island of Tasmania and to analyse the risk factors contributing to mortality and major morbidity. Thirty-seven patients were treated with a median Injury Severity Score (ISS) of 14 (range 9-34). The overall mortality rate of this series was 5.8%. Age, mechanism of injury (blunt or penetrating), delay prior to hospital presentation and modality of treatment (operative or non-operative) were not significant risk factors for mortality and morbidity; however, transfusion requirement of over 10 units of blood (P < 0.005), ISS score of over 20 (P < 0.0005), haemodynamic instability at presentation (P < 0.05) and a Hepatic Injury Score (HIS) grade of 3 or more (P < 0.05) were statistically significant risk factors.

Abdominal Injuries↗
PubMed1993

Binding pattern of eight different lectins in healthy subjects and patients with dysplastic and malignant lesions of the oral cavity.

The present investigation was undertaken to assess the binding characteristics of eight different lectins to normal oral mucosa (11 cases), leukoplakia with varying degrees of dysplasia (five cases), and oral mucosal squamous cell carcinoma (12 cases) by the use of biotinylated lectins and avidin biotin peroxidase complexes. The lectins employed were soybean (SBA), peanut (PNA), Dolichos biflorus (DBA), concanavalin A (Con A), wheat germ (WGA), Ulex europaeus (UEA), Ricinus communis (RCA), and Lotus tetragonolobus (LTA). It was observed that SBA, DBA, WGA, UEA, RCA, and LTA showed very strong to strong binding in healthy oral mucosa but no or very weak binding in squamous cell carcinoma. On the contrary, PNA showed weak binding to normal mucosal epithelial cells but showed strong binding to malignant cells. The dysplastic mucosa had an intermediate binding pattern. The lectin Con A was not bound at all or seen in very low concentration in the malignant cells and dysplastic epithelium, but it showed weak binding in the normal mucosa. Hence, we conclude that lectins may be utilized as probes to determine the dysplastic and malignant status of the oral mucosal epithelium.

Adult↗
PubMed1993

Peptide alpha-amidation activity in human plasma: relationship to gastrin processing.

OBJECTIVE AND DESIGN: C-terminal amidation is an essential processing step towards bioactivation of many peptides including gastrin. This reaction is catalysed by peptidylglycine alpha-amidating mono-oxygenase (PAM, EC 1.14.17.3) which converts the glycine extended precursors on their carboxyl termini to the des-glycine amidated peptide products. In the case of gastrin, most of the amidation is thought to occur in the antrum. However substantial quantities of glycine extended gastrin and PAM are present in plasma. It is unclear whether circulating PAM reflects the secretory activity of the gastrin secreting cell or whether PAM is involved in the postsecretory processing of gastrin. The aim of the present study was to relate the circulating amidation activity to the plasma concentrations of glycine extended and amidated gastrins. PATIENTS AND MEASUREMENTS: Plasma PAM, gastrin-amide and gastrin-gly were measured in subjects with different gastrin secretory status: healthy subjects basally and following a meal, members of families with multiple endocrine neoplasia type 1 (MEN-1) with normal and high plasma gastrin, and patients with hypergastrinaemic atrophic gastritis. RESULTS: Patients with MEN-1 and hypergastrinaemia tended to have a higher plasma PAM activity than MEN-1 subjects with normal circulating G-NH2 indicating a cosecretion of hormone and PAM. However in contradistinction to patients with medullary thyroid carcinoma, PAM activity does not appear to be a useful tumour marker of gastrinoma. Hypergastrinaemia from a non-tumour source (hypergastrinaemic non-atrophic gastritis) was associated with a lower plasma PAM activity than in normal subjects and may reflect the secretion of a greater proportion of already amidated gastrin. In general, there was no relationship between plasma PAM activity and the ratio of amidated to non-amidated gastrin suggesting that circulating PAM was not involved in the amidation of gastrin. Feeding increased circulating gastrin but had no effect on plasma PAM activity. CONCLUSION: The results support the view that gastrin is amidated at the site of its synthesis and that hypergastrinaemia is associated with elevated plasma amidating enzyme activity only when the gastrin originates from tumour sources.

Anemia, Pernicious↗
PubMed1993

Surgical thyroid disease in Papua New Guinea.

A clinical and histopathological analysis was carried out on 376 thyroid specimens removed under various diagnoses from the surgical clinics of Papua New Guinea over a period of 11 years (1980-90). Solitary nodular goitre (solid and cystic) was the most common clinical diagnosis. Nineteen per cent of the solid and 35% of the cystic solitary nodular goitres were found to be malignant. Malignant goitres were confirmed histologically in 73.3% of the clinically diagnosed cases of malignancy. The presence of amyloid goitre (1.9%) posed a significant diagnostic and therapeutic problem due to its clinical features resembling that of malignant goitre. Hemithyroidectomy (lobectomy) was the most common surgical procedure employed for all unilateral thyroid lesions and partial or subtotal thyroidectomy was performed for benign and most malignant lesions.

Adolescent↗