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Biomedical subjects

S C Sharma

Publications and source records attributed to S C Sharma.

At least 127 records · Page 7Linked to original sources
PubMed1993

Role of oestradiol-17 beta in the regulation of synthesis and secretion of human chorionic gonadotrophin by first trimester human placenta.

Inhibition of aromatase, a key enzyme in the biosynthesis of oestradiol-17 beta, by the addition of 1,4,6-androstatrien-3,17-dione resulted in a significant increase in the levels of immunoreactive human chorionic gonadotrophin (hCG) in the medium and tissue. This increase was partially reversed by the simultaneous addition of oestradiol-17 beta. These effects on the levels of immunoreactive hCG were also reflected by the increased levels of mRNA specific for the alpha and beta subunits of hCG following the addition of the aromatase inhibitor. However, addition of tamoxifen resulted in a drastic decrease in the levels of both the messages. Based on these results, it is suggested that the synthesis of hCG is negatively modulated by oestradiol-17 beta in the human placenta.

Androstenedione↗
PubMed1993

Serum lactate dehydrogenase in head and neck malignancy patients.

50 patients of head and neck malignancy were selected for this study while excluding those associated with renal, hepatic, cardiac and metabolic diseases. Age and sex matched even number of controls were also included for comparison. Serum LDH levels in the control group were 124.2 +/- 3.50 I.U./L. Higher levels of LDH were observed in patients with malignancy of head and neck (335.50 +/- 21.60 I.U./L, P < 0.001). Serum LDH level was also related to histopathological stage of malignancy, being higher in poorly differentiated tumour as compared to moderate and well differentiated malignancy. Patients without metastasis had insignificantly lower serum LDH levels as compared to those with metastasis.

Adult↗
PubMed1992

Characterization of novel set of membrane antigens associated with axonal growth. III: Expression in the regenerating goldfish optic nerve and tectum.

In the preceding two papers in this series, a polyclonal antiserum (3070) and several monoclonal antibodies (MAbs 4 and 199) were used to define a novel set of laminin-binding membrane antigens in chick brain. In chick brain, 3070 and MAb 4 antigens stained growing axons and migrating nascent neurons transiently; though projection neurons were intensely labelled at all stages, normal glial cells were stained faintly or not at all. To learn if these antigens are associated more generally with active states of nerve growth, the present paper examined the expression of 3070 and MAb 4 antigens during regeneration of the goldfish optic nerve. Only a few optic fibers or glial cells were stained by 3070 antiserum in the resting (uninjured) optic nerve, but 10 days following a unilateral nerve crush, when the growth response is maximal in these fish, distal regenerating neuritic sprouts and glial cell bodies and processes were profusely labelled. The intensity of labelling was diminished by 135 days post-crush, when most active growth was completed. Since 3070/MAb 4 antigens exhibit properties expected for functional laminin receptors, these findings suggest several possible roles that they could play to aid nerve regeneration.

Animals↗
PubMed1992

Isolation of dermatophytes from clinically normal sites in patients with tinea cruris.

Sixty patients clinically suspected of tinea cruris were studied by collecting skin scrapings from the site of their lesions and six clinically normal sites including the thighs, scrotum, crural clefts, natal cleft and the web between their 4th and 5th toes. Dermatophytes were detected in scrapings in 46 (77%) and by culture in 36 (60%) patients from lesions. Trichophyton rubrum was isolated from 32 and Epidermophyton floccosum from 4 patients. Dermatophytes were also isolated with maximum isolation from the scrotum, crural clefts and the natal cleft in that order. Thus, when tinea cruris is treated with topical antifungal agents they should be applied also to the potential carriage sites to prevent recurrence.

Adolescent↗
PubMed1992

The development of substance P-like immunoreactivity in the goldfish brain.

The development of substance P-like immunoreactivity (SPLI) in the goldfish brain was studied by means of the indirect peroxidase-antiperoxidase technique and an antibody to substance P. By 80 h after fertilization, the first SPLI-cell bodies appear in the ventricular zone of the future diencephalon and the first SPLI-fibers appear in the olfactory bulbs. Two days after hatching (which occurs at 100 h after fertilization), SPLI fibers connecting the olfactory bulbs and hypothalamus are seen. In the optic tectum SPLI-fibers appear for the first time 5 days after hatching. In the brain stem, SPLI-cell bodies appear in juvenile animals 40 days after hatching. The highest number and intensity of SPLI-cell bodies and fibers are found in the area postrema. SPLI-cell bodies are also seen in the gustatory nucleus, nucleus ambiguous, reticular formation of the medulla, dorsal motor nucleus of the vagus and commissural nucleus of Cajal. The significant information gained from the present study is: 1. The rostro-caudal sequence in which the SPLI appears in the developing nuclei of the goldfish brain 2. The reduction of SPLI-cell bodies in some nuclei with age Thus, in the brain stem, SPLI-cell bodies that were labeled in juvenile goldfish were not seen in adults. This might be due to changes in the rate of axonal transport, changes of the SP phenotype during development or cell death. The developmental sequence and relative timing in which SPLI-cell bodies appear in the goldfish, rat and mice are similar.

Aging↗
PubMed1992

Radiation therapy of esophageal cancer: role of high dose rate brachytherapy.

Fifty untreated cases of squamous cell carcinoma arising from the middle one-third of the esophagus, with no apparent extraesophageal spread on a computed tomography (CT) scan and with a Karnofsky performance status of over 70, were treated by external beam irradiation to a dose of 3500 cGy/15 fractions/3 weeks. Twenty-five patients (Group A) received treatment with further external beam irradiation to a dose of 2000 cGy/10 fractions/2 weeks. Another group of 25 patients (Group B) received treatment with high dose rate intracavitary irradiation to a dose of 1200 cGy delivered in two sessions of 600 cGy each a week apart. All patients were assessed symptomatically, endoscopically, and radiologically every 3 months. There was marked difference at the end of 1 year in relief of dysphagia (37.5% in Group A vs. 70.6% in Group B), local control (25% in group A vs. 70.6% in group B) although the results were statistically insignificant (p greater than 0.05) and actuarial survival (44% in group A vs. 78% in group B) which was, however, significant statistically (z = 2.83). The cumulative radiation effect (CRE) by external beam irradiation was 1729 reu and by external beam and intracavitary irradiation 1741 reu, but the biological dose effect was better with external beam and intracavitary irradiation. Eight percent of patients treated by external beam and intracavitary irradiation had strictures in contrast to 4% treated by external beam irradiation alone. Moderate doses of external beam and intracavitary irradiation can give a better local response than external beam irradiation alone for the same biological dose in the treatment of esophageal carcinoma.

Brachytherapy↗
PubMed1992

Photon beam attenuation for a patient support assembly during arc therapy for a medical linear accelerator.

Arc therapy is one of the treatment techniques for small, centrally located deep-seated tumors. However, care must be taken to remove any components that would interfere with the beam as the gantry rotates around the patient. One such component that may interfere with the beam is the patient support assembly (PSA) or treatment table. Beam attenuation factors due to the presence of the couch side-rails and the centerspine bar of the PSA are presented for both 6 MV and 18 MV photon beams of a Clinac 1800 during a 360 degrees rotation. Dose perturbations arising from these obstructions are displayed using an Alderson Rando phantom. A method is described to calculate the start and stop angles for the largest unobstructed arc for a given field size (FS), centerspine bar to the isocenter height (H), centerspine bar width (W), and SAD. As an illustration, for an SAD of 100 cm and a W of 4 cm, the start and stop angles for arc therapy with a FS of 10 x 10 cm2 and an H of 12.7 cm would be 29 degrees and 331 degrees.

Humans↗
PubMed1992

Epidemiology and pathogenesis of paranasal sinus mycoses.

In a prospective study, 50 cases of paranasal sinus mycoses were diagnosed in 2 years out of 119 clinically suspected patients from north India. Young men from rural areas were most commonly afflicted. Patients with paranasal sinus mycoses could be grouped in three clinical varieties: noninvasive, 31; invasive, 17; allergic, 2. Maxillary and ethmoid were the common sinuses concurrently involved in these patients, whereas sphenoid and frontal sinuses were also affected in invasive variety. Aspergillus flavus (80%) was the most common isolate, followed by A. fumigatus (6%). Alternaria species was identified in two patients with noninvasive granuloma. In invasive variety, Rhizopus arrhizus and Candida albicans were the causative agents in two patients and one patient, respectively. Regarding pathogenesis besides epidemiologic factors, the immunologic factors were also evaluated. It was found that presence or absence of precipitating antibody against antigens from the etiologic agents correlates well with disease progression. Allergic factor was found in all varieties, though presence of cell-mediated immunity was demonstrated in 29% patients with noninvasive granuloma only. The combination of skin test against aspergillin and precipitin demonstration at the outset will therefore help in preliminary screening.

Adolescent↗
PubMed1992

Role of calcium in secretion of chorionic gonadotropin by first trimester human placenta.

The role of calcium in regulation of secretion of human chorionic gonadotropin (hCG) by first trimester human placental minces in vitro has been investigated. Depletion of calcium in the medium by addition of EGTA resulted in a drastic decrease in the levels of immunoreactive hCG in the medium with consequent of accumulation of hCG in the tissue. Addition of A 23187 which is a calcium ionophore resulted in a dose dose dependent increase in the hCG in the medium and this stimulatory response could not be observed in the absence of calcium. Use of lanthanum (a calcium antagonist) in place of calcium in the medium used resulted in a significant decrease in the levels of hCG in the medium. Addition of veratridine (a sodium channel activator) stimulated hCG secretion in a dose dependent manner. These results suggest that calcium is essential for normal secretion of hCG by human placenta.

Calcimycin↗
PubMed1992

Adverse reactions to gentamycin in patients with ear, nose or throat infections.

Eighty four patients requiring treatment with Gentamycin were selected from Otorhinolaryngology outpatient and those admitted to the hospital. Patients suffering from hepatic or renal disorders, pregnant women and children were excluded from the study. Seventy three were administered gentamycin 40 mg BD intramuscularly for 7-10 days and in 11 the drug was applied topically as ear drops for 6-12 weeks. Adverse reactions were observed in 9 (13.3%) and 11 (100%) patients given the drug parenterally and topically respectively. In parenteral group incidence was higher in females as compared to males and profile included nausea and vomiting, headache, cough, tinnitis, albuminuria, diminition of hearing and vertigo. Whereas diminition of hearing acuity was observed in all those who had topical application as evidenced by pure tone audiometry.

Administration, Topical↗
PubMed1992

Evaluation of radical treatment of carcinoma esophagus using a combination of external beam and intracavitary irradiation.

Twenty five patients with squamous cell carcinoma arising from the middle third of the esophagus were treated radically, with external radiation, to a dose of 55-60 Gy. All patients had lesions less than 6 cm in length with no extra-esophageal spread on computed tomography scan. Eleven of these patients received additional intracavitary radiation to a dose of 12 Gy, 1 cm from the source axis in two sessions of 6 Gy each, a week apart. There was no significant difference in the relief of dysphagia and survival among these receiving and those not receiving intracavitary radiation. Addition of intracavitary radiation to radical external radiation was associated with significant complications like stricture and fistulae formation, which accounted for the poor results.

Brachytherapy↗
PubMed1991

Detection of coronary artery disease by vasodilator thallium imaging of the heart with amyl nitrite inhalation: a pilot study.

Thallium imaging of the heart using dipyridamole-induced coronary arteriolar vasodilation has proven to be an effective means of detecting significant coronary stenosis. However, intravenous dipyridamole has not yet been made available for general use. We therefore examined the feasibility of substituting amyl nitrite inhalation as an arteriolar vasodilator prior to thallium imaging. Seventeen patients, all of whom had catheterization-proven coronary stenosis, inhaled amyl nitrite for 2-5 min. Thallium was injected after 45-60 s of inhalation. Completion of inhalation was followed immediately by planar imaging. Of 6 patients who inhaled amyl nitrite for at least 4 min, 5 had moderate or severe image defects on immediate scans which completely resolved on delayed scans. Only 3 of 11 who inhaled amyl nitrite for 2 min or less prior to scanning had similarly positive tests. Overall sensitivity for significant stenosis was 8 of 17 (47%). Inhalation was well tolerated with only one episode of angina and hypotension. We conclude that amyl nitrite inhalation for at least 4 min may offer an effective and readily available alternative to intravenous dipyridamole for vasodilator imaging of the heart.

Administration, Inhalation↗
PubMed1991

FNA cytodiagnosis of non-Hodgkin's lymphoma and its subtyping under working formulation of 175 cases.

One hundred thirty-two cases diagnosed as non-Hodgkin's lymphoma (NHL) by fine-needle aspiration cytology (FNAC) and histology, and 43 cases in which there were minor or major discrepancies between cytology and histology for diagnosis of NHL, were reviewed. The diagnostic accuracy of FNAC for NHL was 86.3% at the initial diagnosis. Following review, all the 132 cases initially diagnosed as NHL by cytology and histology remained so with minor changes in subtypes in a few cases. Of the 43 discrepant cases, 28 turned out to be NHL and 6 as Hodgkin's disease (HD); 3 were anaplastic carcinoma; and in 6 cases the discrepancy still persisted. Diagnostic accuracy of FNA for NHL improved to 98.0% following review. Categorization of histologically diagnosed NHL cases under working formulation showed that 10.4%, 21.5%, and 57.7%, respectively, were low, intermediate, and high-grade lymphomas. The corresponding figures were 16.6%, 18.4%, and 60.1%, respectively, in cytology. The diagnostic accuracy of cytology for subtyping was found to be 67.5%.

Adolescent↗
PubMed1991

Working formulation of the non-Hodgkin's lymphomas: a study of cell size and mitotic indices in cytologic subtypes.

Cell size and mitotic indices were studied in 243 non-Hodgkin's lymphomas (NHL) diagnosed cytologically and classified according to the Working Formulation. Low-, intermediate-, and high-grade lymphomas constituted 14.8%, 18.9%, and 61.7% of the cases, respectively. Measurement of the diameter of 100 lymphoid cells in each case showed that in most of the low-grade malignant lymphomas, 50-80% of the cells were small (less than 10 microns). A majority of the cells (an average of 45-60%) in intermediate- and high-grade lymphomas were in the range of 11-15 microns. Only the intermediate-grade large noncleaved and high-grade immunoblastic lymphomas had a majority of their cells (greater than 50%) larger than 15 microns. The mitotic indices (number of mitotic figures per 500 lymphoid cells) showed a highly significant difference between low- (0.7 +/- 1.14), intermediate- (3.0 +/- 2.67), and high-grade (5.4 +/- 3.40) lymphomas using the Wilcoxon's signed rank test (P less than 0.0001). Nearly two-thirds of the cases in each grade were within specific ranges of mitotic indices, i.e., less than 1 for low-, 1-3 for intermediate-, and greater than 3 for high-grade lymphomas.

Adolescent↗