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Biomedical subjects

D Sharma

Publications and source records attributed to D Sharma.

At least 55 records · Page 3Linked to original sources
PubMed2000

Temporal formation of distinct thyroid hormone receptor coactivator complexes in HeLa cells.

Thyroid hormone receptors (TRs) regulate transcription by recruiting distinct coregulatory complexes to target gene promoters. Coactivators implicated in ligand-dependent activation by TR include p300, the CREB-binding protein (CBP), members of the p160/SRC family, and the multisubunit TR-associated protein (TRAP) complex. Using a stable TR-expressing HeLa cell line, we show that interaction of TR with members of the p160/SRC family, CBP, and the p300/CBP-associated factor (PCAF) occurs rapidly (approximately 10 min) following addition of thyroid hormone (T3). In close agreement with these observations, we find that TR is associated with potent histone acetyltransferase activity rapidly following T3-treatment. By contrast, we observe that formation of TR-TRAP complexes occurs significantly later (approximately 3 h) post T3 treatment. An examination of the kinetics of T3-induced gene expression in HeLa cells reveals bimodal or delayed activation on specific T3-responsive promoters. Taken together, our data are consistent with the hypothesis that T3-dependent activation at specific target promoters may involve the regulated action of multiple TR-coactivator complexes.

Acetyltransferases↗
PubMed2000

Orienting to exogenous cues and attentional bias to affective pictures reflect separate processes.

On the basis of psychophysiological research it has been argued that pleasant and unpleasant pictures inhibit orienting to abrupt startle stimuli. Converging psychophysical evidence was sought for this finding using a modified version of the spatial precueing paradigm (Posner, 1980). Specifically, exogenous cues were presented to the left and right of neutral, pleasant and unpleasant picture stimuli. In contrast to the experimental hypothesis, pleasant and unpleasant pictures failed to affect attention to exogenous cues despite slowing overall reaction times in comparison to neutral pictures. This null finding was replicated in a further experiment where rate arousal was varied within the pleasant and unpleasant picture groups. However, unpleasant pictures produced more task interference than pleasant pictures and highly arousing pictures produced more interference than pictures rated low in arousal.

Adult↗
PubMed2000

Attitudes towards mental illness in the Commonwealth of Dominica.

Little is known about the perception of mental illness in the English-speaking Caribbean. This study was conducted in 1995 to determine the attitudes, knowledge, and help-seeking practices for emotional disorders in the Commonwealth of Dominica. Two groups in Dominica were surveyed: 67 community leaders, consisting of nurses, teachers, and police officers; and 135 community members grouped into five socioeconomic strata that were collapsed to three for the analysis. All the respondents were asked to identify and suggest management of individuals with psychosis, alcoholism, depression, and childhood hyperactivity, as depicted in case vignettes. The person in the psychosis vignette was diagnosed as suffering from mental illness by 84.0% of the leaders and by 71.2% of the community members. However, in each of the three other vignettes, fewer than 30% of the respondents thought that mental illness was present. The person with alcoholism was viewed as having a serious problem by only slightly more than half of the respondents. Fewer than half of the respondents thought that the individuals with depression or hyperactivity had serious problems. The community leaders did somewhat worse in recognizing mental illness than did the community members. Respondents were most likely to refer a family member with emotional problems to a medical practitioner. In conclusion, education about mental health problems is needed in Dominica. Especially disconcerting was the lack of knowledge on mental illness among nurses, teachers, and police officers, that is, professionals directly involved in the pathway to care.

Adult↗
PubMed2000

Flow cytometric analysis of androgen receptor expression in human prostate tumors and benign tissues.

Androgen receptor (AR) plays an important role in growth and hormonal therapy of human prostate tumors. Immunohistochemical analysis of AR expression, a nonquantitative technique, is currently used for screening of receptor expression in prostate tissues. The present report describes a laser flow cytometric method for monitoring AR expression in human cell lines and in archival formalin-fixed paraffin-embedded prostate tissues and tumors. Multiparametric flow analysis can be used for simultaneous detection of other cellular markers (e.g., DNA aneuploidy), and by gated analysis, AR expression in subpopulations of a tumor can be quantitatively determined.

DNA, Neoplasm↗
PubMed2000

Lipid profile in smokers and tobacco chewers--a comparative study.

OBJECTIVE: The present study was undertaken to evaluate lipid profile in cigarette smokers and tobacco chewers and to see whether tobacco chewing causes same degree of alteration in lipid profile as done by smoking. METHODS: Serum lipid profile was studied in 30 smokers (Group A), 30 tobacco chewers (Group B) and 30 controls i.e., non-smokers and non-tobacco chewers (Group C). RESULTS: High density lipoprotein-cholesterol was lower both in smoker (P < 0.01) as well as in tobacco chewers (P < 0.001) than the controls. Both smokers and tobacco chewers had higher values of total cholesterol, low density lipoprotein cholesterol, very low density lipoprotein-cholesterol and, triglycerides as compared to non-smoker, non-tobacco chewer group whereas the differences in levels of lipids in smokers and tobacco chewers were not statistically significant. CONCLUSION: Though different mode of addictions, smoking and tobacco chewing have an equal and comparable adverse effects on lipid profile and therefore raising cardiovascular risk in same proportion.

Adult↗
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↗
PubMed1999

D,L-alpha-difluoromethylornithine, an irreversible inhibitor of ornithine decarboxylase, induces differentiation in MEL cells.

In the present study, the effect of D,L-alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), on Friend's murine erythroleukemia (MEL) cell differentiation is investigated. DFMO was able to induce differentiation of MEL cells in culture as determined by haemoglobin (Hb) content and percentage of cells synthesizing Hb detected by benzidine staining. DFMO at a concentration of 2 mM resulted in about 70% benzidine-positive cells on the fifth day. There was a time-dependent increase in the percentage of benzidine-positive cells starting from day three. However, only a 24 h presence of DFMO in the medium was required to induce differentiation suggesting that DFMO switches on a pathway during this period leading to terminal differentiation of MEL cells. DFMO induced differentiation of MEL cells was sensitive to dexamethasone and 5-bromo-2'-deoxyuridine.

Animals↗
PubMed1999

Kite-flying: a unique but dangerous mode of electrical injury in children.

A retrospective study was conducted to evaluate the cause of a sudden rise in number of pediatric admissions with electrical injuries at our centre during the year 1998. In evaluating the cause, six out of twelve admissions were found to be related to kite-flying which is a popular sport during the months of June, July, August and September. In two out of six cases current travelled directly through the string of the kite. In two others, flame burns occured following ignition of clothing. Another patient had contact with wire through a metal rod. In the last case, arcing pulled the hand of the patient leading to direct contact with wire. The average burns size was approximately 31% body surface area (BSA), with all patients having burns over the palmar aspect of at least one hand. No patient required amputation for the injuries. In this article, attention has been focussed on the various modes of electrical injuries associated with kite-flying and some measures have been advised to avoid such accidents.

Adolescent↗
PubMed1999

Effects of losartan versus captopril on mortality in patients with symptomatic heart failure: rationale, design, and baseline characteristics of patients in the Losartan Heart Failure Survival Study--ELITE II.

BACKGROUND: In the Evaluation of Losartan in the Elderly (ELITE) heart failure study, a survival benefit (primarily because of a reduction in sudden deaths) was observed in symptomatic patients treated with losartan compared with captopril. METHODS AND RESULTS: The Losartan Heart Failure Survival Study--ELITE II (currently ongoing) is a double-blind, randomized clinical trial being conducted in 45 countries at 288 sites. ELITE II formally tests the hypotheses that losartan, compared with captopril, will reduce all-cause mortality (primary end point) and sudden cardiac death and/or resuscitated cardiac arrest (secondary end point). In addition, all-cause mortality and/or hospitalizations and cardiovascular mortality and/or hospitalizations will be evaluated. The trial has 90% power to detect a 25% treatment difference in all-cause mortality (event driven, 510 deaths). Substudies are examining quality of life, health care resource utilization, and mechanisms related to the reduction in sudden death. During recruitment (June 1997 to May 1998), 3,152 patients aged 60 years or older (mean age, 71.6 years), with New York Heart Association classes II (51%), III (44%), and IV (5%), and left ventricular ejection fraction of 40% or less (mean, 31%) were randomized to receive either 12.5 mg of losartan, titrated as tolerated to 50 mg once daily, or 12.5 mg of captopril, titrated as tolerated to 50 mg thrice daily. Randomization was stratified by clinical site and for baseline beta-blocker use. CONCLUSION: The ELITE II study will further define the role of losartan in the treatment of patients with symptomatic heart failure relative to the angiotensin-converting enzyme inhibitor captopril, an agent from a class currently considered standard treatment for this disease.

Aged↗
PubMed1999

Carcinoma of oesophagus--aetiological factors and epidemiology: an overview.

Tobacco and alcohol, opium, hot tea and food, bracken and tannins, plant irritants, fungal infection, nitrosamines, nitrates and nitrites, moldy foods and mycotoxins and dietary deficiencies have received attention as aetiological factors for carcinoma of oesophagus. Global epidemiology and epidemiology at the national level show that it has marked regional pattern with steep gradients and marked variations among countries and provinces suggesting a strong aetiological role of environmental risk factors. The aetiological agents for carcinoma of oesophagus appear to be many which may act together or successively upon the oesophagus.

Alcohol Drinking↗
PubMed1999

Diethylhydroxylamine given in vivo inhibits lipid peroxidation and lipofuscin formation in the nervous tissues of rat.

In vivo effects of diethylhydroxylamine (DEHA) on lipid peroxidation and lipofuscin formation in the nervous tissues of rat have been investigated. Rats were fed DEHA for 30, 60 and 90 days and lipid peroxidation levels and lipofuscin concentration measured in cerebellum, brain stem and spinal cord. Lipofuscin contents were also assessed histochemically. The results showed that the drug caused a significant reduction in lipid peroxidation level and lipofuscin concentration related to ageing.

Aging↗
PubMed1998

Randomly amplified polymorphic DNA (RAPD) for evaluating genetic relationships among varieties of guinea fowl.

The present study investigated the use of randomly amplified polymorphic DNA (RAPD) in estimating the intra and inter varietal genetic variation in three varieties of guinea fowl (Lavender, Pearl and White). The estimates, measured as band sharing were high for within population (0.946-0.971) and between population (0.990-0.999) genetic similarity. The respective estimates were 0.898-0.929 and 0.923-0.928 when estimated as frequency of occurrence of bands. The results indicated a very low level of intra and inter varietal genetic variation in these guinea fowl varieties, which in turn suggested the low level of genetic variation in these populations. The possible reasons for this high genetic similarity has been discussed.

Animals↗