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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 1,495 records · Page 83Linked to original sources
PubMedDate not supplied

Longitudinal study of basal cortisol levels in healthy elderly subjects: evidence for subgroups.

A group of 51 healthy elderly volunteer subjects participated in a 3- to 6-year longitudinal study of basal cortisol levels. Once per year basal cortisol levels were examined using hourly sampling over a 24-h period. Analyses of three cortisol measures (last measure obtained, mean cortisol levels across years, and the cortisol slope) revealed that the slope of the regression line measuring cortisol levels at each year was the most predictive measure of cortisol secretion over the years in this elderly population. Cortisol levels were shown to increase with years in one subgroup, to decrease in another, and to remain stable in a third. The age of the subjects was not related to either cortisol levels or to the pattern of change in cortisol secretion over years. Free and total cortisol levels were highly correlated and the groups did not differ with regard to plasma corticosteroid binding globulin. No group differences were observed for weight, height, body mass index, pulse, blood pressure and glucose. However, significant group differences were reported for plasma triglycerides levels as well as high density lipoproteins levels. Positive correlations were reported between the obsession/compulsion subscale of the SCL-90 questionnaire and the cortisol slope of subjects. Finally, previously reported group differences in neuropsychological performance are summarized. Thus, there exists considerable variation in hypothalamo-pituitary-adrenal function amongst aged humans. These results are consistent with recent animal studies showing the existence of subpopulations of aged rats which differ in hypothalamo-pituitary-adrenal activity and cognitive efficiency.

Adrenal Glands↗
PubMedDate not supplied

Iatrogenic tension pneumothorax complicating outpatient Heimlich valve chest drainage.

Use of new technology makes possible the outpatient management of conditions previously requiring inpatient treatment. With increased use of such modalities comes a greater chance that the emergency physician will encounter patients with device-related complications. We report a case of such a complication, a tension pneumothorax presenting to the emergency department following misguided manipulation of a modified Heimlich chest drainage system. It is recommended that physicians opting to utilize such out-patient technology refrain from improvised modifications that may be unfamiliar to subsequent providers.

Adult↗
PubMedDate not supplied

Urinary tract infections-microbial virulence determinants and reactive oxygen species.

The human urinary tract is able to combat with the microbial invasion under normal circumstances. To cause urinary tract infection the organism has to evade the host defense mechanisms by possessing distinct properties which contribute to the virulence of the organism hence called virulence determinants Ninety percent of uncomplicated urinary tract infections are caused by Escherichia coli, hence the knowledge of the virulence determinants of this organism can be extrapolated to other uropathogenic organism as well. Virulence determinants of uropathogenic E. coli include adhesins, siderophore production, polysaccharide coating, hemolysin production, outer membrane proteins etc. The intestinal E. coli, which are the reservoir of E. coli for causing UTI, lack these virulence determinants. On the other hand these virulence determinants enable the organism to colonize and invade the urinary tract. In addition these are important in acquiring the nutrients in other wise nutrient deficient environment. Further, they also help the organisms in triggering an inflammatory response and hence bringing about pathological changes which leads to symptomatic UTI. Severity of symptomatic infections and tissue damage during the infective process depends upon the magnitude of the inflammatory response triggered by the uropathogen which in turn is dependent upon the amount of extrcellular release of reactive oxygen species by the phagocytic cells; hence role of antioxidants as an adjunct to antibiotics in the treatment of infective process needs to be evaluated further.

Adhesins, Bacterial↗
PubMedDate not supplied

LEPTO Dipstick: a rapid and simple method for serodiagnosis of acute leptospirosis.

The LEPTO Dipstick assay is a newly developed test for the diagnosis of leptospirosis and uses a broadly reactive antigen for detecting IgM antibodies. The test was evaluated in the Andaman and Nicobar Islands, using 867 serum samples from known cases of leptospirosis and controls. The efficacy of IgM ELISA was also tested for comparison. The LEPTO Dipstick had a sensitivity of 78.7%, a specificity of 88.3% and a positive predictive value of 91.0%. The test had a good level of agreement with the standard criteria for diagnosis using paired microscopic agglutination tests (kappa = 0.64). These indices were similar to those of IgM ELISA (sensitivity 78.5%, specificity 87.6%, positive predictive value 90.5%, kappa 0.63). Both the LEPTO Dipstick and IgM ELISA had the highest sensitivity during the second, third and fourth weeks of illness (87.6% and 88.2%, respectively). Sensitivities during the first week and after 4 weeks were relatively low but acceptable. The test is very easy to perform and does not require any special skills for its performance. The reagents and dipsticks have a long shelf-life even at room temperature. As the test can be performed without the aid of sophisticated equipment, it is suitable for use at the peripheral level as a rapid screening test for the diagnosis of leptospirosis.

Acute Disease↗
PubMedDate not supplied

Ocular nocardia infections with special emphasis on the cornea.

Nocardia are aerobic, gram-positive, nonmotile and branching filamentous bacteria. Corneal infection by Nocardia is rare. Trauma is the most common predisposing factor. Isolated case reports of nocardial infection associated with contact lens wear and laser in situ keratomileusis (LASIK) have been reported. The clinical picture usually consists of superficial patchy infiltrates, which may be arranged in a wreath pattern. Presence of gram-positive, branching, beaded filaments that stain with 1% acid-fast stain (using 1% sulfuric acid, modified Kinyoun's method) in smears of corneal scrapings is suggestive of nocardial infection. Nocardia grow on commonly used media as tiny, white, dry colonies. Available knowledge and clinical experience suggest that although sulfacetamide eyedrops can be tried as the initial drug, trimethoprim-sulfamethoxazole and amikacin are effective drugs. Once therapy is initiated, the infiltrate responds promptly and resolves, forming a corneal scar with or without vascularization, and good visual recovery can be expected.

Anti-Bacterial Agents↗
PubMedDate not supplied

Antidepressants restore hypothalamic-pituitary-adrenal feedback function in aged, cognitively-impaired rats.

Aged, cognitively-impaired rats (and humans) show hypothalamic-pituitary-adrenal (HPA) hyperactivity that correlates with hippocampal damage. The resultant increase in plasma glucocorticoid exposure is thought to contribute to impaired hippocampal function and to potentiate hippocampal neuron death. In young, adult rats antidepressant drugs increase corticosteroid receptor expression in brain regions known to regulate the HPA axis, leading to increased negative-feedback control and decreased HPA activity. In the present study we examined basal levels of plasma adrenocorticotropin hormone (ACTH) and corticosterone in aged, cognitively-impaired (AI), aged, cognitively-unimpaired (AU) and young, adult (Yg) rats. Plasma ACTH and corticosterone levels were significantly elevated in the AI rats, but only in samples obtained during the diurnal peak. Five weeks of treatment with desipramine (15 mg/kg) significantly reduced evening levels of both ACTH and corticosterone in all groups, and eliminated the group differences. We then examined delayed, glucocorticoid negative feedback in these animals. Among vehicle-treated animals, a bolus injection of corticosterone (10 mg/kg), administered 3 hours prior to testing, completely inhibited the plasma ACTH response to restraint in AU and Yg, but not AI animals. In contrast, plasma ACTH responses to restraint were completely inhibited in AI rats following chronic treatment with desipramine. These findings indicate that the antidepressant, desipramine, decreases HPA activity and increases glucocorticoid negative-feedback sensitivity in AI rats, suggesting that antidepressant drugs may form a useful therapeutic approach to HPA dysfunction in elderly human populations.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Analysis of historical porous building materials by the NMR-MOUSE.

Samples of sandstone with and without deposits of silicon oxide stone strengthener as well as samples of historical brick material were analyzed by transverse NMR relaxation and mercury intrusion porosimetry. Relaxation times and relaxation time distributions of the protons from the water saturated samples were measured by low-field NMR using homogeneous and inhomogeneous fields. The measurements in inhomogeneous fields were performed with two different NMR-MOUSE sensors, one with a field gradient of 2 T/m and the other with an average field gradient of about 20 T/m. In the sandstone samples the application of stone strengtheners was shown to result in a confinement of the large pores within the outer layer of a few millimeters depth. Depending on the ferromagnetic contamination of the brick samples, the relaxation time distributions can be affected. The agreement of T2 relaxation time distributions and pore size distributions from mercury intrusion porosimetry was found to be better for the NMR-MOUSE sensors than for the homogeneous field measurements. This is true even for different brick samples, unless the content in ferromagnetic particles is very strong.

Archaeology↗
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Comparison of septal defects in 2D and 3D echocardiography using active contour models.

Three-dimensional ultrasound is emerging as a viable resource for the imaging of internal organs. Quantitative studies correlating ultrasonic volume measurements with MRI data continue to validate this modality as a more efficient alternative for 3D imaging studies. However, the processing required to form 3D images from a set of 2D images may result in a loss of spatial resolution and may give rise to artifacts. This paper examines a method of automatic feature extraction and data quantification in 3D data sets as compared with original 2D data. This work will implement an active contour algorithm to automatically extract the endocardial borders of septal defects in echocardiographic images, and compare the size of the defects in the original 2D images and the 3D data sets.

Echocardiography↗
PubMedDate not supplied

Recurrent giant cell reparative granuloma of hard palate: role of Tc-99m-MDP three-phase bone scan.

A 42-year-old female presented with pain in the hard palate following surgical curettage for giant cell reparative granuloma. Radiographs of the face at this time did not reveal any abnormality. The surgeons' query was to differentiate fibrosis from recurrence before considering her for recurettage. The three-phase bone scan helped in establishing the diagnosis of recurrence, which was confirmed after histological examination of the curettaged tissue.

Adult↗
PubMedDate not supplied

Results of renal angioplasty in nonspecific aortoarteritis (Takayasu disease).

PURPOSE: To evaluate the long-term results of percutaneous transluminal renal angioplasty (PTRA) in the management of renovascular hypertension caused by nonspecific aortoarteritis (Takayasu disease). MATERIALS AND METHODS: The results of 96 stenoses in 66 patients were retrospectively studied. The indications for PTRA included hypertension uncontrolled by single-drug therapy, evidence of greater than 70% diameter stenosis in the renal artery with a peak systolic gradient of greater than 20 mm Hg, and clinically inactive disease. RESULTS: Technical success was obtained in 91 (95%) stenoses in 62 patients. Clinical success was seen in 59 (89%) and included "cure" in 14 and "improvement" in 45 patients. The stenosis decreased from 88% +/- 6% (range, 70%-100%) to 11% +/- 12% (range, 0%-40%), systolic pressure gradient decreased from 95 mm Hg +/- 22 (range, 30-140 mm Hg) to 9 mm Hg +/- 8 (range, 0-30 mm Hg), blood pressure improved from 181 +/- 16 (range, 150-220)/115 +/- 10 (range, 90-146) to 136 +/- 25 (range, 130-210)/86 +/- 16 (range, 80-130) mm Hg, and the drug requirement decreased from 3.9 +/- .6 (range, 2-5) to 1.1 +/- .9 (range, 0-3) (P value for all < .001). Complications included transient intrarenal arterial spasm in three patients, groin hematoma in two patients, and ipsilateral renal vein injury in one patient. At 22 months +/- 17 (range, 4-84 months) follow-up, the restenosis rate, as determined by recurrence of hypertension and angiographic demonstration of restenosis, was 16%. CONCLUSION: Despite some technical problems, PTRA is safe and effective in treating renovascular hypertension caused by nonspecific aortoarteritis. The complication rate is low.

Adolescent↗
PubMedDate not supplied

Quality of life associated with diabetes mellitus in an adult population.

To ascertain the quality of life associated with the health state of diabetes mellitus using utility value analysis. Consecutive adult patients with diabetes mellitus for at least 1 year and a mean age of 61.7 years (range 21-85 years) were interviewed in a cross-sectional fashion using standardized research methodology. Utility analysis values were obtained employing the time tradeoff method and were correlated with clinical parameters of the sample group, as well as with co-morbidities using the heteroscedastic Student's t-test and multivariate linear regression. The chi(2) distribution to test for independence was used to compare sample subgroups. With a sample of 292 patients, the mean, patient-preference-based, time tradeoff utility value associated with the health state of diabetes mellitus was 0.88 (standard deviation (SD)=0.17; 95% confidence interval (CI), 0.86-0.90). Repeat analysis confirmed the reproducibility of the data. Thus, the average diabetic was willing to trade away 12% of his or her remaining life in return for a diabetic-free health state. Factors associated with a significant decrease in diabetic-associated quality of life included: (1) the requirement for insulin (p=0.05), (2) the presence of depression (p=0.01), (3) the presence of diabetic retinopathy (p=0.03) and the presence of co-morbidities in general (p=0.01). The health state of diabetes mellitus has a significant effect upon patient, preference-based quality of life. The presence of diabetic co-morbidities and dependence upon insulin appear to decrease quality of life. The utility value associated with the health state of diabetes mellitus is of substantial importance for use in the calculation of cost-effective analyses.

Adult↗
PubMedDate not supplied

Substance P-immunoreactive retinal ganglion cells and their central axon terminals in the rabbit.

Retinal ganglion cells are the projection neurons that link the retina to the brain. Peptide immunoreactive cells in the ganglion cell layer (GCL) of the mammalian retina have been noted but their identity has not been determined. We now report that, in the rabbit, 25-35% of all retinal ganglion cells contain substance P-like (SP) immunoreactivity. They were identified by either retrograde transport of fluorescent tracers injected into the superior colliculus, or by retrograde degeneration after optic nerve section. SP immunoreactive cells are present in all parts of the retina and have medium to large cell bodies with dendrites that ramify extensively in the proximal inner plexiform layer. Their axons terminate in the dorsal lateral geniculate nucleus, superior colliculus and accessory optic nuclei, and these terminals disappear completely after contralateral optic nerve section and/or eye enucleation. In the dorsal lateral geniculate nucleus large, beaded, immunoreactive axons and varicosities make up a narrow plexus just below the optic tract, where they define a new geniculate lamina. The varicosities make multiple synaptic contacts with dendrites of dorsal lateral geniculate nucleus projection neurons and presumptive interneurons in complex glomerular neuropil. This is direct evidence that some mammalian retinal ganglion cells contain substance P-like peptides and strongly suggests that, in the rabbit, substance P (or related tachykinins) may be a transmitter or modulator in a specific population or populations of retinal ganglion cells.

Animals↗
PubMedDate not supplied

Cervical schistosomiasis.

We present a case history of a woman who was diagnosed as having cervical schistosomiasis on histology following investigations for abnormal cervical smear. Schistosomiasis of the female genital tract can present with varied symptoms and there is a need for greater awareness of this diagnosis as the number of travellers to schistosomiasis-endemic areas rises. Travellers to these areas should be warned about the risk of swimming in lakes and rivers.

Adult↗
PubMedDate not supplied

Atherosclerosis in Asian Indians with systemic lupus erythematosus.

OBJECTIVES: Atherosclerosis has emerged as an important late complication of systemic lupus erythematosus (SLE). Asian Indians, as an ethnic group, are known to be metabolically predisposed to development of early atherosclerosis. No data on this aspect of SLE are available from Asia. This study was undertaken to find the frequency of atherosclerosis in Indian lupus patients and the factors affecting such an occurrence. METHODS: Carotid artery intimo-medial thickness (IMT) and plaque were used as markers of atherosclerosis. High-resolution B-mode ultrasonography was used to compare carotid IMT and plaque in 50 patients with SLE and 50 age- and sex-matched healthy controls. RESULTS: Patients with lupus (age 31.6+/-10.05, median 30.5 years; disease duration 52.3+/-36.7, median 46 months) exhibited a significantly greater IMT than controls (0.417+/-0.07 vs. 0.362+/-00.07 mm; p = 0.003). Carotid plaques were seen in seven (14%) cases. None of the control population had plaques (p = 0.006). On bivariate analysis, the IMT was significantly affected by age, systolic blood pressure (SBP), disease duration and menopausal status. On multivariate analysis, the only factor significantly affecting IMT was SBP. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) score was the sole factor found to significantly affect the occurrence of plaque. CONCLUSIONS: Asian Indian lupus patients in our study, despite being relatively young and with shorter disease duration, exhibited premature atherosclerosis in the form of significantly thicker intimo-media and plaque. The factors found to affect accelerated atherosclerosis in our cohort were age, SBP, disease duration, postmenopausal status and the SLICC/ACR score.

Adolescent↗
PubMedDate not supplied

The breast cancer prevention diet by Dr. Bob Arnot: unscientific and deceptive--a disservice to American women.

The following report is a critical review of the recently published book by NBC's chief medical correspondent, Dr. Bob Arnot, entitled, The Breast Cancer Prevention Diet: The Powerful Foods, Supplements, and Drugs That Can Save Your Life. The review represents the official opinion of the American Council on Science and Health (ACSH), a nonprofit public health education and advocacy group supported by a board of over 250 scientific and policy advisors. The scientists at the ACSH express their profound concern about the misleading, unscientific, and speculative advice that Dr. Arnot offers to women who wish to reduce their risk of breast cancer, i.e., to all women. The ACSH believes, first, that in the absence of sound, peer-reviewed evidence supporting such advice, there is harm in recommending lifestyle modifications for the purpose of preventing breast cancer. The ACSH also believes that a physician (and particularly one in a position of public trust, such as a professional media health expert) should refrain from selling advice based on the twin philosophies that "you can't afford to wait" for the evidence, and that "you can only improve your health" with this diet. Indeed, unproven interventions such as those put forth in this book can have negative effects on both physical and psychological health. The ACSH contacted many of the scientists quoted or cited in Dr. Arnot's book. Some expressed concerns regarding the book's message or the misrepresentation of their work or both. Those physicians affiliated with the Memorial-Sloan Kettering Cancer Center (MSKCC) in New York, while expressing their concerns about the claims made in the book, informed the ACSH that they had been "advised" not to comment on The Breast Cancer Prevention Diet. The MSKCC public relations office acknowledged that the center had serious concerns about the Arnot book and that these concerns had been conveyed to the publisher, Little, Brown and Co., and to Dr. Arnot. The MSKCC representative noted that Dr. Arnot had "graciously" agreed to delete all references to MSKCC from future editions.

Breast Neoplasms↗
PubMedDate not supplied

CYP1A1 and CYP2D6 polymorphism and risk of lung cancer in a North Indian population.

This case-control study was conducted to examine the association between the CYP1A1 and CYP2D6 genotypes and lung cancer risk among North Indians. The estimated relative risk for lung cancer associated with the CYP1A1 Val/Val allele was 2.68, and was four-fold when cases with small cell lung cancer (SCLC) were considered alone. With regard to the metabolism of debrisoquine, no poor metabolizers were found amongst the subjects. The odds ratio of risk with the heterozygous extensive metabolizer (HEM) genotype was 1.5. However, in the presence of at least a single copy of the variant CYP1A1 MspI allele and the CYP2D6 HEM genotype, the risk was two-fold for squamous cell carcinoma (SQCC). When the CYP1A1 Val/Val and CYP2D6 HEM genotypes were taken together, the risk for SCLC was four-fold. Stratified analysis indicated an interaction between bidi smoking and variant CYP1A1 genotypes on the risk for SQCC and SCLC. Heavy smokers (Brinkman index>400) with Val/Val genotypes were at a very high risk of developing lung cancer (odds ratio 29.30, 95% confidence interval 2.42-355, p=0.008). Heavy smokers with CYP1A1 MspI (CYP1A1*1/2A or CYP1A1*2A/*2A) genotype had a seven-fold risk for SCLC compared with non-smokers. This study is the first to be carried out on a North Indian population, and, although small, suggests that CYP1A1 and CYP2D6 polymorphisms might have a role in determining the risk for lung cancer and should be investigated further.

Alleles↗
PubMedDate not supplied

Experimental models in drug development for helminthic diseases.

The prevalence and socioeconomic impact of helminthic infections continue to be of global concern, particularly in areas with tropical climates, poor sanitation, low standards of living, and poor health education. Considerable progress has been achieved in the development of anthelmintics, and a number of useful model systems are available. The uses and pharmacologic and clinical features of a number of anthelmintics are reviewed.

Animals↗