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Biomedical subjects

V Sharma

Publications and source records attributed to V Sharma.

448 records · Page 25Linked to original sources
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Enzymatic aspects of the phenol (aryl) sulfotransferases.

The sulfotransferases that are active in the metabolism of xenobiotics represent a large family of enzymes that catalyze the transfer of the sulfuryl group from 3'-phosphoadenosine 5'-phosphosulfate to phenols, to primary and secondary alcohols, to several additional oxygen-containing functional groups, and to amines. Restriction of this review to the catalytic processes of phenol or aryl sulfotransferases does not really narrow the field, because these enzymes have overlapping specificity, not only for specific compounds, but also for multiple functional groups. The presentation aims to provide an overview of the wealth of phenol sulfotransferases that are available for study but concentrates on the enzymology of rat and human enzymes, particularly on the predominant phenol sulfotransferase from rat liver. The kinetics and catalytic mechanism of the rat enzyme is extensively reviewed and is compared with observations from other sulfotransferases.

Animals↗
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Dynamics of human follicular growth and in-vitro oocyte maturation.

The physiological trigger for meiotic resumption in the human oocyte is the surge of luteinizing hormone, but it can also occur spontaneously if oocytes are released from antral follicles and cultured in vitro. The development of novel techniques for the culture of murine oocytes has raised the possibility of growing human oocytes to maturity in vitro. Such a system could open the door to a number of techniques with revolutionary consequences. It would clearly be of benefit in basic physiological studies of follicular development, as well as being used to test the effect of toxicological substances on oocyte maturation. More significantly, such a system could provide a source of human oocytes for in-vitro fertilization (IVF) where immature or germinal vesicle oocytes are cultured to maturity before being fertilized. If this can be achieved, it might facilitate oocyte cryopreservation, where surplus oocytes are stored, thus avoiding the need for repeated superovulation. A combination of immature oocyte cryopreservation for later maturation and IVF will provide the opportunity to establish oocyte banks and help overcome some of the practical and ethical dilemmas that are currently shadowing the field of reproductive medicine.

Animals↗
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Monozygotic twinning and IVF/ICSI treatment: a report of 11 cases and review of literature.

Monozygotic twinning is a relatively rare event in in-vivo conception, being estimated to occur in 0.42% of all births. The underlying mechanism for monozygotic twin formation is the division of the embryo early in its development. Separation of cells may theoretically occur before or after inner cell mass formation. In this analysis we report 11 cases of monozygotic twins resulting from IVF or intracytoplasmic sperm injection (ICSI) treatment cycles performed between 1991 and 1998 at St James's University Hospital, Leeds, and Bourn Hall Clinic, Cambridge, UK. Six cases (55%) followed treatment with ICSI and seven cases (64%) were in women aged > or = 35 years. This article also reviews the scientific literature discussing information pertaining to frequency, aetiology and potential complications of the monozygotic twinning phenomenon. We conclude that patients at risk of monozygotic twinning are those aged >35 years of age and those who had artificial opening in the zona pellucida by application of micromanipulation techniques. Women undergoing assisted conception treatment, particularly those with these two risk factors, must be informed of the low but definite risk of monozygotic twinning when counselled regarding the number of embryos to be transferred and chances of multiple births.

Adult↗
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Comprehensive evaluation of complement components in the course of type I (Lepra) and type II (ENL) reactions.

Complement components C1q and C4 of classic pathway; C3d, a breakdown product of C3, and factor B of alternate pathway: and C3, a component both of classic and alternate pathways, were studied in 35 patients, comprising 18 type I (Lepra) and 17 type II (ENL) reactions. There was a significant decrease in C3 and factor B with a concomitant rise of C3d during ENL. These changes indicate their preeminent role in immunogenesis of type II (ENL) reaction. The changes in the classic pathway components, on the other hand, were insignificant, apparently suggesting its limited involvement in ENL. Furthermore, reversion of factor B and C3d after subsidence of reaction is intriguing and may indicate that they are not substantially affected even with contemporary treatment. Complement components, of both classic and alternate pathways, showed no significant alterations either during type I (Lepra) reaction or after its amelioration.

Complement Activating Enzymes↗
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Thrombophilia and dental surgery: a report of dental extraction in a patient with protein S deficiency.

Most patients with thrombophilia are asymptomatic. A case is presented here of a young woman with protein S deficiency, one of the thrombophilias, who required dental extraction. Protein S deficiency predisposes a very small number of those affected to life-threatening thromboses and emboli, for which they are required to take lifelong prophylactic anticoagulation. This report emphasizes the need to liaise closely with haematology departments when deciding whether heparinization is required for patients already taking warfarin. The role of low-molecular-weight heparins is highlighted, a brief review of thrombophilia is given and the management of patients who are taking warfarin and need dental surgery is discussed.

Adult↗
PubMedDate not supplied

Investigation of modality-specific distractibility in children.

Seventy-three nonreferred children were administered a battery of cognitive, academic and behavioral measures along with distinct tests of aural and visual distractibility. The data suggest that distractibility is modality specific. Completely distinct groups of visually- and aurally-distractible children were found. In addition, visual distractibility was associated with both a continuous performance test (CPT) measure of inattention and teacher ratings of behavior, but not with cognitive nor academic achievement measures. In contrast, aural distractibility was associated with cognitive functioning and reading scores, but not with the CPT inattention measure nor teacher behavior ratings.

Achievement↗
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Thrombosis as a complication of extended stay at high altitude.

BACKGROUND: There is limited knowledge about the medical problems of long term stay at high (> 3000 m) and extreme (> 5000 m) altitudes, as these areas are generally considered uninhabitable. METHODS: Prospectively collected clinical records of all patients hospitalized at Command Hospital, Western Command between November 1998 and February 2000 were reviewed to identify thrombotic complications among patients from high and extreme altitude areas as well as those from non-high altitude areas who were < 45 years of age. RESULTS: Of 20,257 hospital admissions during the study period, 1692 were from high and extreme altitude areas. Forty-six patients from these areas had thrombosis-related diseases compared to 17 from non-high altitude areas (odds ratio: 30.49; 95% CI: 17.06-51.67; p < 0.001). The mean (SD) age of all patients with thrombotic complications was 32 (8) years and all were men. The mean duration of stay at high and extreme altitudes of such patients was 10.2 (5.6) months. Only 25 were smokers (mean 5.2 pack-years) and 39 consumed alcohol (mean 54 ml/day). Apart from frostbite in 5, no other medical condition was noted in these patients. The vascular events were deep vein thrombosis (20), pulmonary thromboembolism (6), stroke (15), thrombosis of the abdominal veins (8), and retinal artery and peripheral arterial thrombosis (1 each). The presenting complaint in all patients with thrombosis of the abdominal veins was poorly localized pain in the upper abdomen followed by ascites (6/8). Five of these patients also had a large spontaneous splenic haematoma. None of the patients investigated was found to have a procoagulant disorder. CONCLUSION: Long term stay at high and extreme altitudes is associated with a 30 times higher risk of spontaneous vascular thrombosis. Veins are common sites of such thrombotic events. We also encountered thrombosis of the portal, splenic and superior mesenteric veins in our patients who had stayed at high and extreme altitudes.

Adult↗
PubMedDate not supplied

Portal system thrombosis: a complication of long-term residence at extreme altitude.

BACKGROUND: With induction of the Indian Army to heights over 5,000 meters above sea level, complications of long-term stay at extreme altitude have come to light. We describe our experience with patients developing portal system thrombosis. METHODS: Clinical data were collected over 2 years on patients hospitalized for thrombotic complications from high-altitude (HAA) and non-high altitude (non-HAA) areas. Site of thrombosis was confirmed by imaging or at surgery. Patients were investigated for conditions that predispose to venous thrombosis. RESULTS: Ten cases of portal system thrombosis were seen during the period; of these, 9 (mean age 28 [SD 3.9] years; all men) were from HAA. Mean duration of residence in HAA was 12.4 (4.9) months; two were smokers and six drank 7-22 g alcohol/day at least 5 times a week. The first symptom was abdominal pain; this was later complicated by gastrointestinal bleeding (n=5), fever (7), vomiting (7), and weight loss (5). Average time between onset of first symptom and reaching a tertiary-care hospital was 9.5 (4.7) days. Clinical examination showed ascites (8 cases), splenomegaly (7), and hepatomegaly (6). Mean hemoglobin level at admission was 15.8 (3.4) g/dL. Ascites was hemorrhagic; five cases also had large splenic hematoma. The site of thrombosis was splenic vein (7 cases), portal vein (6), and superior (4) and inferior (1) mesenteric vein. None of 5 patients investigated had any prothrombotic condition. Endoscopic/ sonographic evidence of development of collaterals appeared as early as 12-20 days after onset of symptoms. CONCLUSION: Residence in HAA for extended periods is a risk factor for development of portal system thrombosis. Persistent pain in abdomen in such individuals should raise the possibility of portal system thrombosis.

Adult↗
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Assessment of nutritional status of pre-schoolers in slum areas of Udaipur City.

The present study was conducted in pre-schoolers (2-6 years) from ten different slums of Udaipur City in Rajasthan with the aim to their nutritional status. From the data collected and observations recorded was observed that majority of the subjects were from nuclear family with monthly family income of less than Rs.1500/-. Developmental pattern of these subjects indicated that the height with age of bothe male and female subjects increased, however, their body weight did not increase. More than 50% of these pre-schoolers showed symptoms of protein energy malnutrition and anaemia, while 22% had pigeon chest deformity due to vitamin D and calcium deficiency. Classification for degree of malnutrition as per IAP showed that majority of these subjects (66%) were under weight (Grade I and II). Waterlow's classification revealed that majority of these pre-schoolers were wasted (30%) or wasted and Stunted (42%). This malnutrition was either of PCM (past chronic) or CLM (current long duration) type as per Seoane and Latham's classification.

Child↗
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The treatment of kala-azar during pregnancy.

BACKGROUND: Kala-azar in pregnant women is difficult to treat because for them the two commonly used drugs, sodium stibogluconate and pentamidine, are not considered safe. We assessed the effect of amphotericin B on pregnancy, on the foetus and kala-azar. METHODS: Five pregnant women were administered amphotericin B at a dose of 1 mg/kg body weight daily starting with 0.5 mg/kg body weight till a total dose of 20 mg/kg body weight was given. The progress of pregnancy was monitored ultrasonographically and the mothers and children were followed for six months. RESULTS: All the 5 women were cured of the disease and there was no harmful effect on the children. CONCLUSION: Amphotericin B cures kala-azar during pregnancy with no harmful effects on the foetus.

Adult↗
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Demographic and behavioral factors associated with adolescent pregnancy in Switzerland.

Switzerland has the lowest adolescent fertility rate in Western Europe. According to data collected in 1993 as part of the Swiss Multicentre Adolescent Survey on Health, 5% of 1,726 sexually active adolescents in a group of 3,993 15-20-year-old women enrolled in academic or vocational classes had ever been pregnant; most of these women (80%) had terminated their pregnancy. Adolescents who had ever been pregnant did not differ significantly from those who had not by demographic characteristics. Multiple logistic regression analysis identified seven factors associated with pregnancy: having had four or more sexual partners; not having used contraceptives at first intercourse; ever use of less-effective contraceptive methods; having used illicit drugs during the last 30 days; living apart from one's parents; recently experiencing stress; and perceiving a lack of future prospects.

Adolescent↗
PubMedDate not supplied

O-acetyl sialic acid binding lectin as a probe for detection of subtle change on cell surface induced during acute lymphoblastic leukemia (ALL) and its clinical application.

A novel probe, a 9-O-acetylated sialic acid binding lectin, namely achatininH (ATNH) has been used for the detection of changes on the cell surface during acute lymphoblastic leukemia (ALL). ATNH does not agglutinate normal human erythrocytes, however it is capable of agglutinating erythrocytes and peripheral blood mononuclear cells (PBMC) of patients suffering from ALL. The differential expression of a key receptor, 9-O-acetylated sialo glyco conjugate (9-O-AcSG), on PBMC was observed using a simple lymphoproliferative assay (LA). The extent of expression of 9-O-AcSG was used as an index to distinguish ALL patients of different clinical stages and assess the probability of relapse. The amount of ATNH needed for maximum stimulation served as a tool to indirectly measure the extent of expression of 9-O-AcSG on PBMC surface. The acetylated sialo glycoconjugate was expressed at a very high concentration during acute phase of the disease. Subsequently it decreased during treatment persisted during maintenance therapy and reappeared with relapse. PBMC of normal human donors required 80 times more ATNH in comparison to the untreated acute phase ALL patients. No cross reactivity was found in non Hodgkin's lymphoma, chronic myelogenous leukemia and thalassaemia patients.

Agglutination Tests↗