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Biomedical subjects

S C Sharma

Publications and source records attributed to S C Sharma.

At least 91 records · Page 5Linked to original sources

Results of treatment in endometrial carcinoma: ten years experience.

From 1980 to 1989, 145 patients of histologically proven adenocarcinoma of the endometrium were seen and treated at the Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh, Majority of the patients (84/145) presented with FIGO stage I disease. Relationship of myometrial invasion to grade was highly significant (p < 0.001). One hundred and seven patients were treated by surgery in combination with pre-operative or post-operative radiotherapy. The importance of various prognostic factors was assessed and grade of the tumour had statistically highly significant effect on survival (p < 0.005). Postoperative radiotherapy is recommended in patients with poor prognostic factors.

Combined Modality Therapy↗

Inhibitory effect of iridoids on Epstein-Barr virus activation by a short-term in vitro assay for anti-tumor promoters.

The in vitro anti-tumor promoting effect of the methanolic extracts of iridoids containing three plants and several pure iridoids isolated from other plants, has been evaluated. The alcoholic extracts of Paederia scandens, P. scandens var. mairei and the Ayurvedic herbal remedy Picrorhiza kurrooa were tested against the Epstein-Barr virus. Among the 15 iridoids evaluated, the glycoside, paederoside, displayed the highest order of anti-tumor promoting activity.

Anticarcinogenic Agents↗

Postpericardiotomy syndrome and cardiac tamponade following transvenous pacemaker placement.

This is the first reported case of cardiac tamponade presumed to be caused by postpericardiotomy syndrome (PPS) following endocardial pacemaker placement. An 84-year-old woman developed fever and dyspnea 3 weeks after pacemaker placement. Physical examination revealed hypotension, tachycardia, and pulsus paradoxus. Auscultation revealed clear lungs and diminished heart sounds. The sedimentation rate was 60 mm/h. Echocardiography revealed a large pericardial effusion with signs of cardiac tamponade. Surgical drainage of the pericardial space resulted in complete resolution of symptoms. The pericardial fluid was culture- and cytologically negative. PPS is a common complication of cardiothoracic surgery and chest trauma. It rarely occurs after percutaneous procedures such as percutaneous transluminal coronary angioplasty and transvenous pacemaker placement. While usually having a benign, self-limited course, PPS can cause a serious complication as illustrated in this case report.

Aged↗

Salt-induced changes in lipid composition and ethanol tolerance in Saccharomyces cerevisiae.

The effect of salt stress on lipid composition and its relationship with ethanol tolerance in Saccharomyces cerevisiae was studied. Amounts of phospholipids as well as that of sterols decreased, whereas that of protein and glycolipids increased with increasing salt concentration. Relative proportion of amino phospholipids (phosphatidylethanolamine and phosphatidylserine) decreased, whereas that of phosphatidylcholine showed a reverse trend. Cells grown under increasing salt concentration were more resistant to ethanol-induced leakage of UV-absorbing substances, an index of ethanol endurance. Results showed an overlap between osmotolerance and ethanol tolerance in this strain.

Biotechnology↗

Glutathione-glutathione reductase system and lipid peroxidation in Saccharomyces cerevisiae under alcohol stress.

The content of malondialdehyde (MDA) as well as diene conjugates increased in Saccharomyces cerevisiae under alcoholic conditions. These cells had lower content of water soluble antioxidant, i.e., glutathione. Ethanol-treated S. cerevisiae also exhibited lower activity of glutathione reductase (GR). The decrease in reduced glutathione (GSH) content cannot be attributed completely to lower GR activity. Not only the GSH content was lowered, but oxidized glutathione (GSSG) was also less in ethanol-treated yeast cells. The decrease in oxidized glutathione was much more (84%) as compared to that of reduced glutathione (40%).

Ethanol↗

Rhabdomyosarcoma of head and neck--an analysis of 24 cases.

Clinical records of 24 cases or rhabdomyosarcoma involving head and neck region were studied. Majority of the patients (83.3%) were under five years of age. The common sites of involvement were the middle ear (50%) and the nasopharynx (17%). Embryonal variety was noted in majority of patients (83.3%). Pain and swelling in the post aural or pre-auricular region was the commonest mode of presentation. Last four cranial nerves were involved in eight patients and four patients had extension of the tumor in the posterior cranial fossa. Twenty patients having embryonal rhabdomyosarcoma received combination of chemotherapy and radiotherapy. Half of these remained tumor free upto six months. Surgical extirpation was done only in two patients, where the disease was localised. The tumor in these two patients was of pleomorphic variety and did not recur till two years after surgery.

Adolescent↗

Expression of extracellular domain peptides of the FSH receptor and their effect on receptor-ligand interactions in vitro.

Follicle-stimulating hormone receptor (FSH-R) displays considerable homology to luteinizing hormone receptor (LH-R) in structure and amino acid sequence. Comparison of the sequences of the extracellular domains (ECD) of the receptors reveals two regions (amino acids 4-56 and 265-319 in FSH-R) that share relatively little amino acid sequence similarity. This suggests that these variable regions may be important in providing specificity of ligand binding. We have expressed overlapping ECD peptides containing one or both of these regions (RFI, amino acids 5-125; RF2, amino acids 201-319; and RF3, amino acids 5-319) as fusion proteins in E. coli using pRSET vector. The presence of polyhistidine at the N-terminal end allowed substantial purification of the expressed proteins by a single step of affinity chromatography. The purified peptides were characterized for direct binding of hormone and their ability to block the binding of FSH and LH to the receptors. None of the peptides bound labelled hormone, while all peptides inhibited the binding of FSH to its receptor in a dose-dependent manner. However, only RF2 peptide inhibited ligand binding in a hormone-specific manner. These data suggest there is a site between amino acids 201-319 of the FSH-R ECD that is involved in FSH binding.

Amino Acid Sequence↗

Large retinal ganglion cells in the channel catfish (Ictalurus punctatus): three types with distinct dendritic stratification patterns form similar but independent mosaics.

Retinal ganglion cells in the channel catfish (Ictalurus punctatus) were retrogradely labelled, and those with the largest somata and thickest primary dendrites were categorized by their levels of dendritic stratification. Three types were found, each forming a mosaic making up approximately 1% of the ganglion cell population. Using a system based on established sublaminar terminology, we call these the alpha-a (alpha a), alpha-b (alpha b), and alpha-c (alpha c) ganglion cell mosaics. Cells of the alpha a mosaic had large, sparsely branched trees in sublamina a at 10-30% of the depth of the inner plexiform layer (IPL), sclerad to those of all other large ganglion cells. Some alpha a somata were displaced into the IPL or inner nuclear layer (INL) but belonged to the same mosaic as their orthotopic counterparts. Cells of the alpha b mosaic had dendrites that branched a little more and arborized in sublamina b at 50-60% of the IPL depth. Many also sent fine branches into sublamina a, and some were fully bistratified in a and b. The alpha c cells arborized in the most vitread sublamina, sublamina c, at 80-95% of the IPL depth. The soma areas of the three types in the largest retina studied ranged between 139 microns 2 and 670 microns 2 with significant differences in the order alpha a > alpha c > or = alpha b. Analyses based on nearest-neighbour distance (NND) and on spatial auto- and cross-correlograms showed that each mosaic was statistically regular and independent of the others. Mosaic spacings were similar for each type, giving mean NNDs of 242-279 microns in the largest retina and 153-159 microns in a smaller one. Correspondences between these mosaics, previously defined large ganglion cell types in catfish, and other mosaic-forming large ganglion cells in fish and frogs are discussed along with their implications for neuronal classification, function, development, and evolution.

Animals↗

Association of hypersensitivity and carriage of dermatophytes in clinically normal sites in patients with Tinea cruris.

Forty nine patients with mycologically confirmed Tinea cruris were investigated for the association of hypersensitivity to trichophytin and the isolation of dermatophytes from clinically normal sites with chronicity and recurrence of infection. At the end of six months following specific therapy, 24 patients returned for follow up and they were similarly studied. Dermatophytes were isolated from clinically asymptomatic sites in 46% patients before treatment and in 21% of the patients on follow up. Immediate weal reaction and increased concentration of IgE antibodies were seen in 73% and 80% of the patients respectively. However, the delayed hypersensitivity reaction was more associated with patients having lesions for more than 6 months (48%) in comparison with patients with a short history (17%). On follow up after 6 months, the different hypersensitivity reactions and IgE antibody concentration maintained more or less the same association. Therefore in persistent or recurrent Tinea cruris infection, besides potential carriage in clinically normal sites, hypersensitivity to antigens of dermatophytes possibly plays an important role in pathogenicity.

Adolescent↗

The enantiomeric separation of metipranolol and desacetylmetipranolol on a cellulose tris-3,5-dimethylphenyl-carbamate chiral stationary phase.

A high-performance liquid chromatographic (HPLC) method is described for direct separation of the enantiomers of metipranolol and its principal degradation product and main metabolite, desacetylmetipranolol. Separations are performed on a chiral stationary phase of cellulose tris-3,5-dimethylphenyl carbamate (Chiralcel OD), with hexane-propan-2-ol-diethylamine elution and UV detection at 278 nm. The method affords identification and determination of the optical purity of the bulk drug and its formulated ophthalmic products.

1-Propanol↗

A comparison of surface doses for two immobilizing systems.

To achieve accurate and reproducible treatments, many types of immobilizing systems have been used. Two of these systems: Alpha Cradle and VacFix, conform around the patient to improve day-to-day treatment repositioning. The Alpha Cradle system has been in clinical use for several years. The system involves two polyurethane chemicals which upon mixing in a latex bag will expand and harden around the patient. The second system (VacFix) uses a 0.15 mm thick plastic bag loosely filled with 1 mm polysterol spheres. The patient lays on the bag in the treatment position and the air is evacuated from the bag. This system retains its shape for the entire treatment and can be re-used. In some patient set-ups, it is possible that the beam is modified as it passes through these devices, causing a potential change in the target dose and an increase in the patient surface dose. CT scans of the Alpha Cradle and VacFix systems were performed and relative densities were calculated and compared to air. Material densities and surface dose data for a Cobalt-60 teletherapy unit and a dual photon linear accelerator are presented.

Cobalt Radioisotopes↗

Role of 17 beta-estradiol and progesterone in the regulation of synthesis and secretion of chorionic gonadotropin by the first trimester human placenta.

The role of 17 beta-estradiol and progesterone in the regulation of synthesis of chorionic gonadotropin (CG) by first trimester human placenta has been studied using 1,4,6 androstatriene 3-17-dione to block the synthesis of 17 beta-estradiol or tamoxifen to block its action at receptor level and RU486 to block the action of progesterone at the receptor level. Results indicate that the synthesis of CG is negatively modulated by 17 beta-estradiol and positively modulated by progesterone as judged by the change in the levels of immunoreactive CG, alpha- and beta-CG mRNA and in vitro translation, as well as biosynthesis of alpha- and beta-CG and, finally, nuclear run off transcription.

Androstatrienes↗

Programmed cell death of retinal ganglion cells during experimental glaucoma.

The death of retinal ganglion cells during glaucoma is thought to result from damage to their axons as they exit the eye through the lamina cribrosa. In this study, intraocular pressure in the rat was increased to twice the normal average by cauterizing two limbal-derived veins. To investigate whether retinal ganglion cells in the glaucomatous eye follow an apoptotic type of death, DNA breaks in nuclei were labeled in situ, using a method that specifically incorporates biotinylated deoxynucleotides by exogenous terminal deoxynucleotidyl transferase to the 3'-OH ends of DNA. The active nature of the death mechanism was demonstrated by the reduction in numbers of biotin-labeled nuclei after administration of the protein synthesis inhibitor, cycloheximide. Our results suggest that retinal ganglion cells of the adult rat die through apoptosis when the intraocular pressure is markedly increased. This raises new possibilities in the treatment of glaucomatous damage to the retina, by the potential interruptibility of a program for neuronal death.

Animals↗

Role of reactive oxygen species in renal damage in experimental leprosy.

Renal involvement is known to occur in leprosy. In the present study the possible role of reactive oxygen species (ROS) in causation of renal damage in mice infected with Mycobacterium leprae has been investigated. At least six animals from each group (control and infected) were killed at 0 day, 3, 6 and 9 months postinfection. The results showed a significant increase in the chemiluminescence (CL) response of peritoneal macrophages which was maximum between 3 and 6 months. No significant increase was observed in CL response of blood neutrophils. A significant increase in lipid peroxidation was observed at 3 and 6 months as evident by an increase in malondialdehyde levels. The increased ROS production might be the cause of lipid peroxidation. The renal damage is alos evident by decrease in the activity of renal brush border membrane enzymes, namely, alkaline phosphatase, leucine aminopeptidase and r-glutamyl transpeptidase. Thus ROS might play a role during early stages of M. leprae infection but in the later stages other immunological mechanisms may overpower the effect of ROS.

Alkaline Phosphatase↗