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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 433 records · Page 24Linked to original sources
PubMed2000

Physiological profile and predictors of cycling performance in ultra-endurance triathletes.

BACKGROUND: To report physiological profiles, and investigate the relationship between selected physiological variables and cycling performance in ultra-endurance triathletes. METHODS PARTICIPANTS: ten male (mean+/-SD, age; 32+/-5 years) ultra-endurance triathletes participated in the study. Physiological profiles were compared with 10 male age-matched control subjects. MEASURES: left ventricular structure (wall thickness [LVPWd], internal diameter [LVIDd], and mass [LVM]) and function (diastolic filling, fractional shortening, and stroke volume [SV]) were assessed using standard M-Mode, 2D, and Doppler echocardiography. Maximal and sub-maximal exercise gas exchange responses were measured on-line during a maximal ramping cycle-ergometer exercise test. RESULTS: Ultra-endurance triathletes demonstrated significantly larger LVPWd, LVIDd, LVM, SV, VO2max anaerobic threshold (AT), and power to body-mass ratio compared with controls. Cycling performance for both Ironman and half Ironman were significantly correlated with LVPWd, LVM, and SV. LVIDd was significantly correlated Ironman cycle time alone. Oxygen consumption (VO2) at AT, percentage of VO2max at AT, and peak power to bodymass ratio were significantly correlated to bike finish time in the half Ironman, but not Ironman. CONCLUSIONS: The correlation between cycling performance, LVM and SV suggests that the more conditioned athletes may be better able to maintain a high cardiac output during prolonged cycling. Sub-maximal gas exchange responses are predictors of cycling performance for the half-Ironman but not the Ironman. These results suggest that other factors including the longer duration swim prior to the cycling component, may impact upon cycle performance.

Adult↗
PubMed2000

A comparison of commonly used anti-emetics for the prevention of emetic sequelae after a major gynaecological surgery.

STUDY DESIGN: Prospective, randomized, double-blind, placebo-controlled study involving one hundred ASA I-II patients undergoing major gynaecological surgery. OBJECTIVE: To study anti-emetic efficacy of intravenous (IV) ondansetron (4 mg), droperidol (2.5 mg), metoclopramide (10 mg), and placebo. PATIENTS AND METHODS: 100ASA physical status I-II undergoing major gynaecological surgery were randomized to receive intravenously (IV), one of the four test drugs 10 minutes before the end of anaesthesia. The incidence of postoperative nausea and vomiting following a standard anaesthetic technique was assessed. RESULTS: A significantly large number of patients who received ondansetron (88%) and droperidol (72%) were free of emetic sequelae when compared to placebo (41%); p < 0.05 (power of this observation is approximately 80% at the given significance level). Metoclopramide was ineffective. Patients given droperidol were significantly more sedated than those receiving ondansetron; p < 0.05. This is not surprising, as the dose of droperidol used in this study was higher than that currently recommended because we found lower doses to be ineffective in controlling nausea and vomiting in this group of patients. CONCLUSION: It was concluded that, of the drugs studied ondansetron is the best choice for anti-emetic prophylaxis after major gynaecological surgery.

Adult↗
PubMed2000

Pyelonephritic potential of Pseudomonas aeruginosa in ascending mouse model.

The suitability of female BALB/c and Swiss Webster (LACA) strains of mice for an ascending model of pyelonephritis for human uroisolate of Pseudomonas aeruginosa, was assessed. A fresh isolate of Ps. aeruginosa elaborating virulence factors like elastase, protease, phospholipase C, pyochelin and haemolysin was selected and introduced transuretherally in mice without any manipulation of the urinary tract. This isolate was able to colonize and persist in the renal tissue till day 12 post infection. Histopathologically, severe renal lesions i.e., abscesses formation was observed. The LACA strain was found to be more susceptible to infection with the selected Ps. aeruginosa isolate.

Animals↗
PubMed2000

Superior oblique palsy in a patient with a history of perineural spread from a periorbital squamous cell carcinoma.

A 74-year-old man experienced vertical diplopia. Two years earlier, he was diagnosed with a squamous cell carcinoma of the periorbital frontal skin, with perineural spread involving the ophthalmic division of the right trigeminal nerve and the right facial nerve. The clinical findings were consistent with a right fourth cranial nerve palsy. Computerized tomography and magnetic resonance imaging demonstrated a discrete mass involving the belly of the right superior oblique muscle. An anterior orbitotomy and biopsy demonstrated a mass extending into the belly of the superior oblique muscle. Histology revealed an infiltrating squamous cell carcinoma. The possibility of perineural, direct, or metastatic spread to the superior oblique muscle should be considered in a patient with a history of squamous cell carcinoma of the head and neck. The authors believe this case to be the first report of superior oblique underaction due to involvement of the muscle by squamous cell carcinoma, presumably because of perineural spread. Diagnosis was made possible by neuroimaging and histopathology. There was good short-term resolution of the patient's diplopia after radiotherapy.

Aged↗
PubMed2000

Primary fibrosarcoma of brain.

This is a case presentation of a young patient with an intracranial space-occupying lesion following multiple episodes of generalised tonic clonic seizures for the last 20 years. Such a long latency period between the onset of fits and the discovery of an intracranial lesion is highly unusual in malignant brain tumours. This lesion was excised completely and proved to be a primary lesion of the brain - fibrosarcoma. These rare tumours of mesenchymal origin in the central nervous system are very rare.

Adult↗
PubMed2000

Health care in the 21st century: evidence-based medicine, patient preference-based quality, and cost effectiveness.

The combination of evidence-based medicine, patient-based preferences using utility analysis, and econometric modeling yields a model to evaluate the incremental cost effectiveness of health care interventions. This methodology allows a comparison of the cost effectiveness of virtually all health care interventions and incorporates the patient voice to provide an information system that can improve the quality of health care and simultaneously reduce costs. It has been estimated that such an information system could save more than $90 billion per year of the annual $1.3 trillion health care bill in the United States.

Cost-Benefit Analysis↗
PubMed2000

A study of lupus anticoagulant in unexplained fetal wastage.

Lupus Anticoagulant, first discovered in patients of SLE, is now known to be associated with a wide spectrum of diseases. The presence of LA is associated with adverse fetal outcome in an obstetric population. In the present series the incidence of LA was found to be 16.6% and 80% of LA positive subgroup had an unsuccessful outcome.

Abortion, Habitual↗
PubMed2000

Expression of CXCR4 in the brain of feline immunodeficiency virus infected cat.

Advances in understanding the mechanisms of human immunodeficiency virus (HIV)-1 entry have revealed that the cell surface CD4 expression alone is insufficient and needs an additional molecule on its surface for the viral entry. These are G-protein coupled seven transmembrane (7-TM) family molecules (chemokine receptor) and amongst them one is CXCR4. Feline homologue of CXCR4 acting as a co-receptor for feline immunodeficiency virus (FIV) entry is already reported for the Crandle feline kidney cells strain (CrFK) of FIV. An experiment was carried out to search the expression of CXCR4 retrospectively in FIV (CrFK) infected cat brain tissues using immunohistochemically in the formalin fixed paraffin sections against 12G5, a mouse monoclonal antibody to CXCR4. We observed the expression of this receptor in feline neurons, astrocytes and in some vascular endothelial cells. The study of expression of CXCR4 in the brain, which is one of the many chemokine receptors in the central nervous system, may provide further insight into the interactions between brain cells, pathogens, and the immune system, and help understand the pathogenesis of HIV dementia.

AIDS Dementia Complex↗
PubMed2000

Keratocyte loss in Acanthamoeba keratitis: phagocytosis, necrosis or apoptosis?

PURPOSE: Pathogenesis of Acanthamoeba keratitis involves breakdown of epithelial barrier, stromal invasion by Acanthamoeba, loss of keratocytes, inflammatory response and finally stromal necrosis. The loss of keratocytes, believed to be due to the phagocytic activity of the parasite, occurs disproportionate to and independent of the parasite load, thereby suggesting additional modes of cell loss. To test our hypothesis that the loss of keratocytes in Acanthamoeba keratitis is due to apoptosis, we did both histology and histochemistry on the corneal tissues. METHODS: Routine Haematoxylin and Eosin, Gomori's Methenamine Silver and Periodic acid Schiff stained sections of five corneal tissues from penetrating keratoplasty and eviscerated eyes were reviewed. TUNEL staining was done for morphological detection of apoptosis in three cases, using formalin-fixed, paraffin-processed tissues. RESULTS: Histological changes were epithelial ulceration, loss of keratocytes in all layers, inflammation in anterior two-thirds of the stroma with necrosis, and deeper quiet stroma. Acanthamoeba trophozoites were found in the anterior stroma while the cysts were more in the deeper stroma, with minimal or no inflammatory response. TUNEL staining was positive in keratocytic nuclei in all layers. CONCLUSIONS: This study demonstrates that one of the modes of keratocyte loss in Acanthamoeba keratitis is by apoptosis, possibly in addition to the necrotic process and phagocytic activity of the parasite. The death of inflammatory cells also appears to be mediated by apoptosis.

Acanthamoeba↗
PubMed2000

Acute lymphoblastic leukaemia with giant intracytoplasmic inclusions--a case report.

Acute Lymphoblastic Leukaemia (ALL) with intracytoplasmic inclusions is a rare and unusual subtype of acute leukaemia. Here we describe a case of ALL with intracytoplasmic inclusions in an adult female. These inclusions stained negative for Myeloperoxidase (MPO), Sudan Black E (SBB) and alpha-naphthyl acetate estarase (ANAE) and positive for Periodic Acid Schiff (PAS). This case is being presented for its unusual occurrence and to recognise the characteristics of this subtype of ALL to avoid a misdiagnosis of AML.

Adult↗
PubMed1999

T cell-derived IL-10 promotes lung cancer growth by suppressing both T cell and APC function.

We have found previously that human lung cancers potently induce T lymphocyte IL-10 production in vitro. To assess the impact of enhanced T cell-derived IL-10 on antitumor immunity in vivo, we utilized transgenic mice expressing IL-10 under the control of the IL-2 promoter. We have shown previously that Lewis lung carcinoma cells (3LL) have more aggressive growth potential in IL-10 transgenic mice compared with control littermates. In this study, we show that transfer of T cells from IL-10 transgenic mice to control littermates transferred the IL-10 immunosuppressive effect and led to enhanced 3LL tumor growth. In addition to changes in T cell-mediated immunity, professional APC from IL-10 transgenic mice were found to have significantly suppressed capacity to induce MHC alloreactivity, CTL responses, and IL-12 production. Tumor Ag-pulsed dendritic cells from IL-10 transgenic mice also failed to generate antitumor reactivity. These results suggest that increased levels of T cell-derived IL-10 severely impair antitumor immunity in vivo, due to defects in both T cell and APC function.

Adoptive Transfer↗
PubMed1999

Peptide models for inherited neurodegenerative disorders: conformation and aggregation properties of long polyglutamine peptides with and without interruptions.

Several neurodegenerative diseases are caused by expansion of polyglutamine repeats in the affected proteins. In spino-cerebellar ataxia type 1 (SCA1), histidine interruptions have been reported to mitigate the pathological effects of long glutamine stretches. To understand this phenomenon, we investigated the conformational preferences of peptides containing both the uninterrupted polyglutamine stretches and those with histidine interruption(s) as seen in SCA1 normals. Our study suggests that substitution of histidines by glutamines induces a conformational change which results in decreased solubility and increased aggregation. Our findings also suggest that all the polyglutamine peptides with and without interruption(s) adopt a beta-structure and not random coil.

Ataxin-1↗