PubMed HealthSearch

Biomedical subjects

S M Sharma

Publications and source records attributed to S M Sharma.

At least 19 recordsLinked to original sources

Hypoglycemia as a possible factor in the induction of vasovagal syncope.

Glucose level was estimated in capillary blood of 16 patients, who had vasovagal syncope during exodontia with local anaesthesia. One consistent finding was the low blood sugar level in all patients during syncope, as compared with the level 1 hour after recovery. Hypoglycemia can be induced by parasympathetic activation; this may be the product of reflex conditioning. Modest lowering of blood sugar levels can also act in synergy with hypotension and hypocapnea to induce loss of consciousness. Psychogenic syncope may be mediated through a mechanism involving hypoglycemia. Reflex conditioning perhaps accounts for the small but consistent fraction of the adult population who have repeated fainting episodes.

Adolescent

Differentiated thyroid carcinomas in children and adolescents.

An analysis of differentiated thyroid carcinomas in children and adolescents revealed that the incidence was 3.05% of total number of patients with differentiated thyroid cancers in all age groups. There was a female preponderance. The incidence of papillary, follicular and papillary with follicular elements was equal. There were no papillary carcinomas observed in children younger than 10 years. The predominant mode of presentation was a solitary nodule of thyroid and some of them had associated cervical adenopathy. A considerable number presented with only cervical adenopathy. The incidence of nodal metastases was 50% at time of presentation and lung involvement was present in 15% of children at the time of diagnosis. Radioiodine treatment was given in 70% of children. Ablation was achieved in 86% of patients given two doses of radioiodine (200 millicuries). The more resistant cases were those with lung and nodal metastases. There was complete ablation in 100% with only residual thyroid tissue, 83% in those with associated nodal metastases, and 57% in those with lung involvement. Average duration of follow-up was 10.3 years (range, 2 to 19 years). Recurrence rate or relapse was observed in 8.5% and was in the regional nodes. There was no recorded mortality due to the disease.

Adenocarcinoma

TSH receptors in human thyroid tumours.

To evaluate the binding of human TSH (h-TSH) to various human thyroid tumours using radio receptor assay technique, 26 thyroid tumour specimens were examined. Five specimens did not show displacement by stable h-TSH. A wide variation was observed in B0, non specific binding, affinity and capacity of TSH in all the tumours examined. The Scatchard analysis of the binding of h-TSH to thyroid membranes suggested the presence of the receptors in 57.7 per cent (15 of 26, Ka much greater than 10(9)) and more than one component in 46 per cent (12 of 26) of the tumours studied. There was no consistent pattern of the binding of TSH for thyroid tissue with respect to its pathology. However, with 35 pairs of observations log affinity appeared to be linearly related to log capacity with a slope -0.95, intercept 9.96 and r value -0.93.

Binding Sites

Clinical evaluation of 99mTc(V)-dimercapto succinic acid (DMSA) for imaging medullary carcinoma of thyroid and its metastasis.

99mTc(V)-DMSA kits developed by the Radiopharmaceutical Division, Bhabha Atomic Research Centre, have been evaluated for potential use in scanning medullary carcinoma of the thyroid and its metastases. There were 15 patients with proved medullary carcinoma and 6 patients with other differentiated thyroid carcinoma. Amongst the 15 patients with medullary carcinoma, 12 (80%) showed positive localisation either in the primary or one or more metastatic sites. None of the six patients with carcinoma other than medullary showed increased concentration of 99mTc(V)-DMSA. Of the 37 known metastatic sites in 15 patients with medullary carcinoma, 24 showed concentration of 99mTc(V)-DMSA (64.9%). In addition, 99mTc(V)-DMSA concentration was seen in 14 sites where no evidence of metastasis was revealed. The incidence of 99mTc(V)-DMSA concentration in soft tissue and bone metastasis was similar.

Adult

Monoclonal antibodies to human thyroglobulin: production and characterization.

Human thyroglobulin was used as an antigen for the development of monoclonal antibodies by the hybridoma technique. Spleen cells of BALB/c mice immunized with human thyroglobulin were fused with SP2/0 mouse myeloma cells. Seven clones secreting specific monoclonal antibodies to thyroglobulin were established. Two of these monoclonal antibodies have been purified and characterized. Their equilibrium association constants (Ka) as determined by Scatchard analysis were 0.24 X 10(11) L/M and 1.4 X 10(11) L/M respectively. The specificity of both these antibodies was validated by immunohistochemical staining of human tissues (normal human thyroid, brain, salivary gland, skeletal and smooth muscle, mucous membrane, parathyroid, adrenal) obtained from autopsy material. Only follicles and follicular cells of thyroid tissue were stained by both the monoclonal antibodies. H10 I monoclonal antibody was used for constructing a standard curve for in vitro immunoassay using a solid phase ELISA technique. The minimum amount detectable was 7.8 ng/ml. Thirty six sera from patients of various thyroid disorders were evaluated using ELISA and compared with conventional RIA. A good agreement was seen (r = 0.92) between the two techniques. These specific monoclonal antibodies may prove to be valuable for in vitro immunoassays and in vivo immunoscintigraphy.

Antibodies, Monoclonal

Preparation and evaluation of 99mTc(V)-DMSA complex: studies in medullary carcinoma of thyroid.

Consequent to the promising results reported with 99mTc(V)-DMSA for imaging certain types of soft tissue tumors, we have developed methods to prepare this radiopharmaceutical in three ways: from freshly prepared reagents, through the use of a two component kit and use of the standard renal DMSA kit by a modified recipe. The 99mTc(V)-DMSA complex has been subjected to paper electrophoretic and chromatographic procedures and also biodistribution studies. The distinctly different behaviour of this new product compared to that of the well known renal DMSA complex has been clearly established. Scintiimaging in a preliminary clinical trial in patients with medullary carcinoma of the thyroid has been encouraging.

Carcinoma

Influence of initial large dose on subsequent uptake of therapeutic radioiodine in thyroid cancer patients.

Fifty-two patients with differentiated thyroid cancer, following thyroidectomy were studied by administering a quantity of up to 5 mCi of [131I]sodium iodide. In most of these patients, radioiodine uptake values obtained with the subsequent therapeutic dose were markedly lower than those observed with the initial doses. This observation was verified in seven of the patients with differentiated thyroid cancer, by measuring the radioiodine uptake with a second dose of 4.5 mCi of [131I]sodium iodide. Calculations showed that the major etiology was probably therapeutic irradiation of the thyroid by the first dose.

Combined Modality Therapy

Assimilation of Indian immigrant adolescents in British society.

Assimilation into British society was studied with first- and second-generation Indian immigrant adolescents and English boys and girls (N = 395, age range 14-16 years). They were administered a questionnaire designed by Danziger to monitor changes in their cultural perspectives, such as sex role specialization, autonomy in everyday life, and parents' perceived expectations. Analysis of variance revealed that no changes occurred among second-generation Indian girls, who enjoyed less autonomy in their daily lives than English girls and boys did. Second-generation Indian girls also perceived greater expectations from both parents to play a more responsible role in household activities. Few significant changes were found for Indian boys.

Acculturation

Synthesis of thyroglobulin in thyroid carcinoma patients after radioiodine therapy.

Endogenously radioiodinated thyroglobulin (Tg) and the serum concentration of Tg have been measured in patients with metastatic thyroid carcinoma after therapeutic doses of radioiodine. Serial samples of blood were analyzed for both these parameters over a period of 10 to 22 days. The specific activity of Tg (cpm/ng) was calculated for each sample. Among the six patients studied, three showed constant specific activity. The specific activity of the other three fell, indicating the entering of newly synthesized Tg into the circulation. The respective amounts of Tg entering into the circulation in these three patients were 120, 852, and 20,935 ng/ml serum/day.

Carcinoma

Disappearance rate of endogenously radioiodinated thyroglobulin and thyroxine after radioiodine treatment.

Endogenously radioiodinated thyroglobulin (tg) and thyroxine (T4), in the circulation following, therapeutic doses of radioiodine were studied in five patients with differentiated thyroid carcinoma. Radioactive serum was fractionated on a Sephadex G-200 and the various radioactive peaks thus obtained were analyzed for their biochemical and immunologic characteristics using precipitation with trichloroacetic acid (TCA) and antithyroglobulin antibody extraction with acidified n-butanol and electrophoresis on agar gel. The disappearance rates of endogenously labelled tg and T4 were 3.12 +/- 0.396 days and 10.14 +/- 1.81 days, respectively.

Adenocarcinoma

Serum thyroglobulin differentiated thyroid carcinoma: histological and metastatic classification.

Serum thyroglobulin (tg) levels were measured in 112 patients with proved differentiated thyroid carcinoma (6 pre-operative, 32 post-operative and 74 in whom thyroidectomy was followed by radioiodine treatment). The tg levels were within the normal range in patients who had a residual mass in the neck region after surgery and who were in remission. The patients with metastases showed a wide range (undetectable to microgram quantities) of tg in circulation. The analysis of serum tg with respect to histology showed that the follicular variety of carcinoma tends to show higher tg in serum than the papillary type. Metastatic involvement of bone was associated with much higher serum tg levels than other sites such as lung and lymph node. Thirteen patients with bone metastases of non-thyroidal primary origin had tg levels within the normal range. Serum tg estimation is useful in excluding thyroid as a primary site in patients with bone metastases of unknown primary origin.

Adult

Zollinger-Ellison syndrome with pneumopericardium.

A 55-year-old white male was found to have the Zollinger-Ellison syndrome in 1971. Supposed total gastrectomy was performed at that time. When an esophageal ulcer was found, six years later, esophagoscopic biopsy revealed residual gastric mucosa. The patient was given cimetidine 300 mg qid because it was felt he could not tolerate further surgery. After eight months of cimetidine therapy, the patient was admitted to the hospital because of retrosternal pain. Pneumopericardium was discovered, and at autopsy a large penetrating gastrojejunal ulcer was demonstrated.

Biopsy