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Biomedical subjects

R Sharma

Publications and source records attributed to R Sharma.

At least 235 records · Page 13Linked to original sources
PubMed1998

Granular cell ameloblastoma of jaw. A report of rare case and brief review of literature.

Ameloblastoma is an epithelial odontogenic tumour of the jaw and exhibits diverse microscopic patterns which occurs either singly or in combination with other patterns. The rare granular cell variant is seen in combination usually with follicular or plexiform subtypes. The reported case reveals the microscopic patterns characteristic of granular cell variant only, which is uncommon. The tumour was excised and no recurrence has been observed after nineteen months of surgery.

Adult↗
PubMed1998

Prevalence of serum antibodies to LA-1 oncoprotein, herpes simplex virus type-2 glycoprotein and human papillomavirus type 16 transactivator (E2) protein among Indian women with cervical neoplasia.

Prevalence of serum antibodies to synthetic peptide to oncoprotein of LA-1 known as oncogene of herpes simplex virus type-2, herpes simplex virus type-2 glycoprotein-D as an determinant of viral pathogenicity and human papillomavirus type 16 transactivator E2 protein was studied among 46 Indian women with cervical neoplasia using immunoblot assay for HSV-2 gD glycoprotein and LA-1 antibodies as well as peptide ELISA assay to detect HPV16 E2 antibodies. The seropositivity to LA-1 oncoprotein was found to be high (61%) among patients with invasive cervical carcinoma as compared to 35% in various grades of cervical intraepithelial neoplasia (CIN) and 36% in normal control women. In contrast to this, a uniformly high frequency of antibody to HPV 16 E2 was observed among women with CIN (68%), normal healthy controls (50%) and invasive cervical carcinoma (43%). However, a low frequency of seropositivity (13%) to recombinant vaccinia virus HSV-2 gD protein was found among 15 tested sera each from group of women with various grades of CIN as well as invasive cervical carcinoma as compared to 28% among seven normal healthy control. A negative correlation of LA-1 and HPV16 E2 seropositivity on patient by patient comparison among CIN and invasive cervical carcinoma group was observed which is statistically significant (P = 0.019 for CIN; P = 0.038 for invasive cervical carcinoma). However, a positive correlation (P = 0.144) was found among normal control women. The study has shown a desirable serological marker of cervical neoplasia. This serological marker could be employed as a screening tool in conjunction with cytopathological screening to diagnose women harbouring LA-1 oncogene associated cervical lesions.

Adult↗
PubMed1998

Hormonal regulation of malate-aspartate shuttle enzymes during postnatal development of mice.

The regulation of malate-aspartate shuttle enzymes by hydrocortisone was studied in the liver and kidney of 15-, 30- and 60-day old mice. It has been observed that adrenalectomy decreases and hydrocortisone treatment to adrenalectomized mice increases the activity of cytosolic and mitochondrial malate dehydrogenase and cytosolic aspartate aminotransferase in the liver of 15-, 30- and 60-day old mice. Per cent decrease following adrenalectomy remained almost similar in all the postnatal ages studied. However, hydrocortisone effect shows age-dependency. In the kidney, adrenalectomy decreases and hydrocortisone treatment increases the activity of these isoenzymes only in 30- and 60-day old mice. These findings entail that the same enzyme in different tissues of developing animals may be regulated differentially by the same physiological stimuli. Our findings on hormonal regulation of malate-aspartate shuttle enzymes show that they are subjected to different physiological control in various tissues during postnatal development of mice.

Adrenalectomy↗
PubMed1997

Severe hypoxic biventricular dysfunction in tetralogy of Fallot: is Blalock shunt the answer?

In a 4-year-old boy with tetralogy of Fallot, a right modified Blalock-Taussig anastomosis was created because of severe myocardial dysfunction and repeated hypercyanotic spells. Post-operatively, systemic oxygen saturation improved and also myocardial function. It is postulated that hypoxia was responsible for myocardial dysfunction previously, and its elimination has resulted in markedly improved cardiac performance.

Child, Preschool↗
PubMed1997

Aortic atherosclerosis and perioperative stroke in patients undergoing coronary artery bypass: role of intra-operative transesophageal echocardiography.

Intra-operative transesophageal echocardiography was performed in 126 patients undergoing coronary artery bypass grafting. Significant protruding atheromas (grade IV and V; Katz et al., 1992) were present in 12 patients (9.5%). Protruding atheromas had significantly higher incidence in patients above 60 years in age. Preoperative assessment with chest roentgenography and angiography, as well as intra-operative assessment by surgical palpation proved to be insensitive in detecting aortic atheromas. Out of four patients with grade V atheromas, two (50%) developed right hemiplegia postoperatively. For the rest, patients with grade V atheromas and eight patients with grade IV atheromas, surgical technique was modified and that helped in preventing occurrence of perioperative stroke.

Adult↗
PubMed1997

A human gene encoding morphine modulating peptides related to NPFF and FMRFamide.

FMRFamide-related peptides have been isolated from both invertebrates and vertebrates and exhibit a wide range of biological effects in rats. We show here that in humans 2 FMRFamide-related peptides are encoded by a single gene expressed as a spliced mRNA. The larger predicted peptide (AGEGLNSQFWSLAAPQRFamide) differs from the peptide isolated from bovines (AGEGLSSPFWSLAAPQRFamide) by the substitutions of 2 amino acids. The shorter predicted peptide (NPSF, SQAFLFQPQRFamide) is 3 amino acids longer than the bovine 8 amino-acid NPFF (FLFQPQRFamide) or the human NPFF peptide isolated from serum [5], suggesting that the encoded protein is subject to cleavage by a tripeptidyl peptidase or by a novel processing mechanism. On rat spinal cord, the larger peptide is indistinguishable in activity from the equivalent bovine peptide whereas the smaller extended peptide is inactive.

Action Potentials↗
PubMed1997

Enhancement of prostate tumor volume definition with intravesical contrast: a three-dimensional dosimetric evaluation.

PURPOSE: To assess the impact of intravesical contrast during computed tomography (CT) simulation on prostate tumor volume definition and dose distribution. METHODS AND MATERIALS: Sixteen patients with localized adenocarcinoma of the prostate underwent CT-based virtual simulation in preparation for definitive radiotherapy. Patients were immobilized with a foam cradle and an initial CT was performed after oral but without intravesical contrast (noncontrast scan). A second scan was performed following administration of intravesical contrast (contrast scan). Beam apertures were designed on the noncontrast scans and digitized into the contrast scan file. Beam apertures were also designed on the contrast scans. Isodose plans were generated for several beam apertures and arrangements. RESULTS: There was enhanced visualization of the prostate at the cephalad portion of the field for 15 of the 16 cases. The mean differences between the noncontrast and contrast volumes was significant (p = 0.0001). The mean percent underdosage to the prostate ranged from 3.9% to 18.6%, depending upon the target volume and beam arrangement. CONCLUSION: This study demonstrates the necessity of using intravesical contrast for defining the location of the prostate during CT simulation. The underestimation of the extent of the prostate when omitting intravesical contrast leads to significant underdosage. The value of intravesical contrast is most evident when small (prostate only) conformal fields are used.

Adenocarcinoma↗
PubMed1997

A thermostable D-hydantoinase isolated from a mesophilic Bacillus sp.AR9.

A thermostable hydantoinase has been characterized from a mesophilic Bacillus sp.AR9. The hydantoinase produced by this Bacillus sp.AR9 is strictly D-specific and is constitutively produced with high yields (4500 U/ml) in this strain. The enzyme is not only alkalo- and thermostable but has a pH and temperature optimum of 9.5 and 65 degrees C, respectively, which is advantageous for the bioconversion of DL-5-monosubstituted-hydantoin derivatives. The enzyme has a half life of 80 minutes at 70 degrees C and loses only 33% of its activity in 4 hr at 60 degrees C. The enzyme has a broad substrate specificity with a maximum of 100% with hydantoin and about 26% with dihydrouracil. Co+ + ions enhance the activity of the enzyme by more than 60%.

Amidohydrolases↗
PubMed1997

The unusual imaging appearance of primary retroperitoneal teratoma: report of a case.

Primary retroperitoneal (RP) teratoma is a rare entity which has a distinctive imaging appearance. We describe herein the case of a 25-year-old man in whom a RP teratoma was found to have an extremely unusual imaging morphology by ultrasound and computed tomography (CT). The tumor was resected and histopathological examination confirmed the diagnosis of primary benign RP teratoma.

Adult↗
PubMed1997

The influence of diet on the mucin carbohydrates in the chick intestinal tract.

The presence of nutrients in the intestinal lumen is a major factor influencing bacterial colonization in poultry. This study was conducted to investigate the effects of poultry feed on viscosity of intestinal contents and on mucin carbohydrates by comparing jejunal supernatants and the histochemical composition of goblet cells in chicks reared to 5 weeks of age on either a conventional maize-based diet or a wheat-based diet or a wheat diet supplemented with 0.1% xylanase. Regional differences in the distribution of the neutral, carboxylated and sulphated mucins were demonstrated using conventional histochemical techniques, while a panel of lectins was used to study alterations in glycoconjugate synthesis of mucins in chicks fed different diets. 1) Feeding a diet supplemented with xylanase lowered the viscosity but increased the amount of neutral, carboxylated and sulphated mucins in the jejunum. 2) In chicks fed a maize-based diet, neutral mucins increased in the surface and upper crypt goblet cells of the small and large intestines but decreased in the caecum. 3) Feeding a diet supplemented with xylanase modified crypt-surface glycosylation of N-acetylglucosamine residues and resulted in loss of sialic acid residues in the small and large intestines. These results indicate that the constituents of poultry feed, in particular the consumption of a diet supplemented with xylanase, lead to changes in intestinal viscosity and mucin composition which are associated with alterations in the goblet cell glycoconjugates of the chick intestinal tract.

Animal Feed↗
PubMed1997

Clinical observation of the temporal association between crack cocaine and duodenal ulcer perforation.

HYPOTHESIS: To determine if a cause-effect relationship exists between crack cocaine use and duodenal ulcer perforation (DUP). PATIENTS AND METHODS: A retrospective study was conducted of all patients undergoing emergency surgical management for peptic ulcer disease over a 6-year period at a large inner-city municipal teaching hospital. The hospital records of 78 consecutive patients presenting with complications of peptic ulcer disease between April 1990 and April 1996 were reviewed. Group A (n = 24) consisted of patients with confirmation of crack cocaine usage within 8 hours of clinical presentation; group B (n = 54) consisted of patients with no antecedent history of crack cocaine use. Demographic data, timing of drug use, clinical presentation, laboratory and radiographic findings, toxicology screening, operative findings, and postoperative course were compared between the two groups. RESULTS: Both groups revealed a similar gender distribution, tobacco use, prior peptic ulcer symptoms, and laboratory findings. Group A patients were younger (t test, P = 0.01) and more likely to present with perforation, whereas patients in group B presented with a combination of symptoms (chi square, P = 0.03). Duodenal ulcer perforation was present in 75% of patients in group A compared with 46% of patients in group B (chi square, P = 0.04). Group B patients had a significantly longer hospital stay compared with those in group A (t test, P = 0.01). Both crack cocaine and alcohol are independent predictors of duodenal ulcer perforation. CONCLUSIONS: Patients with recent use of crack cocaine and/or alcohol are more likely to present with duodenal perforations. Although a temporal association between crack cocaine use and duodenal ulcer perforation was demonstrated, this study does not confirm a cause-effect relationship. A prospective cohort study is needed to clarify the pathogenesis of this potential cause-effect relationship.

Adult↗
PubMed1997

Isolation of bioactive compounds from Helix aspersa nerve tissue and the effect of pQPPLPRYamide on heart, esophagus and central neurons of H. aspersa and rectum of Anodonta woodiana.

1. Both acetone and methanol extraction was used to isolate bioactive compounds from 1000 Helix aspersa brains. 2. Seven compounds were isolated of which four were identified as follows: Ha-1, 5-hydroxytryptamine; Ha-3, GSPYFVamide; Ha-4, pQPPLPRYamide; Ha-5, SGYLAFPRMamide. There was insufficient material to identify Ha-2, Ha-6 and Ha-7. 3. Ha-4, pQPPLPRYamide, was found to excite the heart of H. aspersa, relax the esophagus and both excite (mainly) and inhibit central neurons. In addition, this peptide contracted the rectum of Anodonta woodiana. 4. It is concluded that pQPPLPRYamide is an example of a new molluscan peptide family, designated as PRYamide.

Animals↗
PubMed1997

Positive epileptiform discharges in children with neuronal migration disorders.

Most epileptiform abnormalities show a negative polarity on EEG. Focal positive spike waves have rarely been identified in seizure disorders and are generally associated with physiological and neurological impairment. Results of EEG, computed tomography, MRI, and pathologic studies of 15 children with focal neuronal migration disorders who underwent surgery for refractory localization-related epilepsy were compared to examine the association between positive discharges and other findings. Subjects were studied both ictally and interictally by scalp EEG with the International 10-20 system and zygomatic or sphenoidal electrodes, and video EEG telemetry. The 5 children with positive discharges were significantly more likely to develop hemiparesis during the preoperative period (P < or = .025). Correlations were observed between positive discharges and lesions apparent on MRI situated around the rolandic fissure (P < or = .025). Children with positive discharges had a significantly less favorable outcome after surgical treatment (P < or = .025). Positive epilepti-form discharges in children with neuronal migration disorders may signal a more dysfunctional cortex leading to a focal neurological deficit or a more extended lesion than is detected on MRI. This would explain the less favorable outcome of seizures after surgery, since the epileptogenic areas and neuronal migration lesions cannot be completely resected.

Brain↗
PubMed1997

On the tissue/species dependence of cathepsin B isozymes.

Characterization of cathepsin B from buffalo kidney and goat spleen showed the presence of isozymes in case of the goat spleen (GSCB-I and GSCB-II) whereas cathepsin B from buffalo kidney exhibited only one form (BKCB). The molecular weights determined by SDS-PAGE for GSCB-I, GSCB-II, and BKCB were 25.7, 26.6 and 25.5 kDa respectively. The kinetic parameters (Km and Vmax) of GSCB-I showed close similarities with BKCB against alpha-N-benzoyl-DL-arginine-2-napthylamide whereas GSCB-II was closer to the buffalo enzyme with regards to its activity against Z-Arg-Arg-MCA and Z-Phe-Arg-MCA. All the three enzymes had similar sensitivities towards urea, antipain and leupeptin. However, clear differences were observed in the inhibition patterns of the enzyme with iodoacetic acid and iodoacetamide. Differences in the kinetic, immunogenic and some catalytic properties of GSCB-I and II, which had similarities with regard to most of their physico-chemical properties, were considered to be due to the existence of two isozyme forms in goat spleen cathepsin B preparations. Absence of such a multiplicity in forms of the enzyme from buffalo kidney was accordingly attributed to the absence of cathepsin B isozymes in this species. These observations taken together therefore, indicate a probable species/tissue dependence of cathepsin B.

Animals↗
PubMed1997

Identification of a strong promoter of bacteriophage MB78 that lacks consensus sequence around minus 35 region and interacts with phage specific factor.

A strong promoter of bacteriophage MB78 does not have minus 35 consensus sequence although it has a TGn motif immediately upstream of minus 10 sequence as well as the AT rich UP element. It is efficiently recognised by the sigma 70 RNA polymerase, however, a phage-specific factor competes with sigma 70 RNA polymerase for binding to this region, the binding of the factor being stronger than that of the polymerase. Contrary to the reports in the literature the polymerase appears not to bind to the UP element whereas the phage-specific factor does. The latter seems to be involved in the regulation of the promoter activity.

Amino Acid Sequence↗