Search PubMed⌕ Search

Biomedical subjects

B Shah

Publications and source records attributed to B Shah.

At least 73 records · Page 4Linked to original sources
PubMed1991

Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians.

The hypothesis that the high mortality from coronary heart disease (CHD) in South Asians settled overseas compared with other populations is due to metabolic disturbances related to insulin resistance was tested in a population survey of 3193 men and 561 women aged 40-69 years in London, UK. The sample was assembled from industrial workforces and general practitioners' lists. In comparison with the European group, the South Asian group had a higher prevalence of diabetes (19% vs 4%), higher blood pressures, higher fasting and post-glucose serum insulin concentrations, higher plasma triglyceride, and lower HDL cholesterol concentrations. Mean waist-hip girth ratios and trunk skinfolds were higher in the South Asian than in the European group. Within each ethnic group waist-hip ratio was correlated with glucose intolerance, insulin, blood pressure, and triglyceride. These results confirm the existence of an insulin resistance syndrome, prevalent in South Asian populations and associated with a pronounced tendency to central obesity in this group. Control of obesity and greater physical activity offer the best chances for prevention of diabetes and CHD in South Asian people.

Adult↗
PubMed1991

A direct comparison of pharmacologic effects of retinoids on skin cells in vitro and in vivo.

The purpose of these studies was to directly compare the pharmacologic effects of retinoids on cutaneous cells in vitro and in vivo. Previously, it was demonstrated that all-trans-retinoic acid stimulates the proliferation of growth-arrested human keratinocytes and fibroblasts in culture. In the present studies, all-trans-retinoic acid was compared to three other retinoids--13-cis-retinoic acid, P-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-napthalenyl-1-p ropenyl] benzoic acid (TTNPB) and M-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-napthalenyl-1-p ropenyl] benzoic acid (meta-carboxy-TTNPB]--for growth stimulation using a cultured human squamous epithelial cell line (UM-SCC-1) and human dermal fibroblasts. These four retinoids were also evaluated for their effects on reduction of horn-filled utriculi when topically applied to the skin of rhino mice. All-trans-retinoic acid stimulated proliferation of both fibroblasts and epithelial cells over concentrations ranging from 0.01 to 1.0 micrograms/ml. In fibroblasts, 13-cis-retinoic acid was less potent than all-trans-retinoic acid, whereas, in epithelial cells these two retinoids were equipotent. In contrast, TTNPB was more potent than all-trans-retinoic acid at stimulating the growth of both fibroblasts and epithelial cells. The analog, meta-carboxy-TTNPB was essentially inactive as a growth stimulator of both cell types. In the rhino mouse utriculus reduction model, the rank order of potency for the retinoids was the same as that for in vitro cell growth stimulation (TTNPB greater than all-trans-retinoic acid greater than 13-cis-retinoic acid). Meta-carboxy-TTNPB was inactive at reducing utriculi at a dose of 5,000 times the ED50 of TTNPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Inhibition of epithelial cell adhesion by retinoic acid. Relationship to reduced extracellular matrix production and alterations in Ca2+ levels.

Human squamous epithelial cells maintained in growth factor-deficient medium were examined for sensitivity to all-trans retinoic acid (retinoic acid). Under conditions of low external Ca2+ (0.15 mmol/l [millimolar]), or high external Ca2+ (1.4 mmol/l), retinoic acid stimulated proliferation. Concomitantly, cell-substrate adhesion was decreased. Enzyme-linked immunosorbent assays were used to assess production of two extracellular matrix components, ie, fibronectin and thrombospondin. In the presence of retinoic acid, production of both was decreased. Because both fibronectin and thrombospondin serve as epithelial cell adhesion factors, the decreased production of these moieties could contribute to reduced adhesion. Using 45Ca2+ to measure total cell-associated Ca2+ and the Ca2(+)-sensitive dye Indo-1 to measure intracellular free Ca2+, it was found that concentrations of retinoic acid that altered cell-substrate adhesion in the squamous epithelial cells had no effect on total, cell-associated Ca2+, but reduced intracellular free Ca2+ by 50% to 60%. Because Ca2+ is a regulator of adhesion, the ability of retinoic acid to modulate Ca2+ levels in the squamous epithelial cells may explain, in part, how retinoic acid influences their adhesiveness.

Calcium↗
PubMed1989

Influence of thymoxamine eye-drops on the mydriatic effect of tropicamide and phenylephrine alone and in combination.

In a preliminary experiment in 12 healthy volunteers, one drop of thymoxamine 0.5% instilled into the conjunctival sac completely reversed the mydriasis produced by phenylephrine 2.5%, 5% and 10% after 20 minutes. In a second study in eight volunteers, thymoxamine 0.5% completely prevented the mydriasis produced by phenylephrine 2.5% and produced a miosis. It also completely reversed the mydriasis produced by tropicamide 0.5%. The mydriatic effect of tropicamide 0.5% plus phenylephrine 2.5%, however, was not completely reversed by thymoxamine 0.5% over a period of 180 minutes. Phenylephrine, tropicamide and thymoxamine are freely available for use by registered optometrists.

Adolescent↗
PubMed1989

A newer avenue for evaluation of thyroid dysfunction.

Attempt has been made to rationalise the biochemical assessment of patients suspected to have thyroid dysfunction by introduction of a new rapid and supersensitive immunoradiometric assay (IRMA) for TSH. 294 patients were subjected to thyroid investigation viz; tT3, tT4 and TSH (IRMA). Of these, 51 (17.34%) were hypothyroid, 22 (7.48%) were hyperthyroid and 221 (75.1%) were euthyroid. The ratio of thyroid disorder in male to female was 1:3.38. In all patients with hyperthyroidism TSH (IRMA) was 0.05 to undetectable and it was more than 4.5 ulu/ml in hypothyroid patients. TSH (IRMA) was low in one euthyroid patient a 0.34% incidence of false negativity. In 2 patients with subclinical hyperthyroidism TSH (IRMA) was low while tT3 and tT4 were normal. TSH (IRMA) therefore may obviate the need for more time consuming and expensive TRH test and simplify the approach to thyroid function tests in patients suspected to have masked or overt hyperthyroidism.

Adolescent↗
PubMed1988

Current experience with renal transplantation in older patients.

Older patients (greater than 50 years old) are generally considered to be at high risk in renal transplantation, particularly those receiving cadaveric kidneys. The outcome in 53 older patients (mean age, 54 years; range, 50 to 64 years) receiving transplants between January 1, 1980 and December 31, 1986 and followed through June 30, 1987 were analyzed. Before 1984, immunosuppression consisted of azathioprine and prednisone (AP); thereafter, triple therapy (TT)--low-dose cyclosporine, azathioprine, and prednisone--was used. The overall 1-, 3-, and 5-year actuarial patient survival was 87%, 84%, and 84%, respectively. Survival for living related donor (LRD) transplant recipients was 100%, 92%, and 92%; survival for cadaveric (CAD) transplant recipients was 81%, 81%, and 81%. The overall graft survival was 74%, 66%, and 66% at 1, 3, and 5 years, respectively; graft survival was 88%, 81%, and 81% for LRD transplant recipients and 68%, 58%, and 58%, for CAD recipients. The patient and graft survival rates were better in the TT group than in the AP group. Eight patients died after transplantation; six within the first year. The causes of patient death were infection (50%), cardiac (25%), and malignancy (25%). Rejection (56%) and patient death (38%) accounted for most of the grafts lost. Patient and graft survival rates in diabetic patients were not significantly different from survival rates in nondiabetic patients. Results in recipients of ten secondary and one tertiary transplant were poor, with only four of 11 grafts functioning at 1 year.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Alport's syndrome: risk of glomerulonephritis induced by anti-glomerular-basement-membrane antibody after renal transplantation.

Two patients with Alport's syndrome developed glomerulonephritis induced by anti-glomerular-basement-membrane (anti-GBM) antibody after renal transplantation. One patient presented at 5 months after transplantation the second patient 18 months after transplantation. Both grafts failed and the patients returned to dialysis. Our observations suggest that the patients with Alport's syndrome are at risk of developing anti-GBM antibody type glomerulonephritis in the transplanted kidney. This does not occur in the early period after transplantation, probably because of heavy immunosuppression.

Adult↗
PubMed1984

Quantitative assessment of growth and function of the cardiac chambers in the normal human fetus: a prospective longitudinal echocardiographic study.

We assessed the changes in cardiac chamber size, architecture and function in the normal fetus in a prospective, longitudinal, two-dimensional, and two-dimensionally directed M mode echocardiographic study. Serial echocardiograms were recorded in 16 normal fetuses at 4 week intervals from 20 weeks gestation to parturition. Fetal gestational age was assessed by biparietal diameter. Left ventricular, right ventricular, and left atrial chamber sizes and aortic diameter all increased linearly with age. The ratios of right and left ventricular diameter, left atrial to aortic diameters, and relative left ventricular wall thickness that we used as an index of short-axis left ventricular architecture remained constant. Fractional right ventricular and left ventricular wall thicknesses were similar both on echocardiograms and in postmortem hearts over the same range of gestational ages. In addition, postmortem right ventricular and left ventricular free wall weights were indistinguishable and contributed the same proportion to total heart weight throughout gestation. Left ventricular echocardiographic mass increased linearly from a mean of 0.86 +/- 0.09 to 7.47 +/- 2.43 g at term and corresponded closely with postmortem left ventricular weight. We conclude that (1) fetal cardiac chamber dimensions, wall thicknesses, and left ventricular mass increased with gestational age, (2) cardiac architecture in terms of the ratios of right ventricular/left ventricular diameters, left atrial/aortic diameters, and relative wall thickness remained constant, (3) right and left ventricular fractional shortening did not change with age, (4) left ventricular mass assessed echocardiographically corresponded closely with postmortem left ventricular weights in fetal hearts of similar gestational ages, and (5) the similarities between right and left ventricular sizes, wall thicknesses, and free wall weights in this study do not support the theory of right ventricular dominance in the human fetus.

Echocardiography↗
PubMed1984

Embryonal carcinoma of testis in elderly men.

A rare case of pure embryonal carcinoma of the testis in a man in the seventh decade of his life is presented. We believe this is the only reported long-term survivor of embryonal carcinoma of the testis in this age group. A review of the literature on germ cell testicular tumor in men sixty years old and over is also presented.

Aged↗
PubMed1983

Noninvasive ergonovine maleate provocative testing for coronary artery spasm: the need for routine thallium-201 imaging.

We administered ergonovine and used both electrocardiographic monitoring and thallium-201 [201Tl] imaging to detect reversible ischemia in 100 patients. Patients already established as having coronary artery spasm and those with nonbypassed, proximal, high-grade coronary artery stenosis were excluded. No complication occurred in any patient. The use of thallium imaging in addition to electrocardiographic monitoring resulted in a higher degree of sensitivity than did ECG monitoring alone. Fourteen patients demonstrated evidence of coronary artery spasm as documented by 201Tl imaging but of the 14, significant ECG changes occurred in only 50%, and classic ST segment elevation in 21%. Thus, in carefully selected patients the noninvasive provocation of coronary spasm can be accomplished safely, but ECG monitoring must be combined with thallium-201 imaging to achieve an acceptable degree of sensitivity.

Adult↗
PubMed1976

Liver storage iron in Canadians.

Liver samples were collected at 105 (78 males and 27 females) autopsies carried out on accident victims in seven cities of Canada. The age of individuals ranged from newborn to 89 years but about 75% of them were 19 to 65 years old. The liver iron stores of males were high at birth (150 to 300 mug/g), decreasing to around 100 mug/g in the second year. This level was maintained up to about 15 years and then increased to approximately 250 mug/g in 2 to 3 years. After 55 years, the hepatic iron stores tended to decrease. Although the number of samples from females was small, there was an indication of high stores (above 200 mug/g) at birth followed by a decline to values from 50 to 150 mug/g. This level was generally maintained in females throughout life. Storage iron in the livers of stillborn infants was high, ranging from 200 to 1600 mug/g. Analysis of liver samples from 64 persons (50 males and 14 females) who died of cardiovascular diseased showed that males under 45 years had lower iron stores than the corresponding accident victims.

Adolescent↗
PubMed1975

Hamartomatous polyp of the esophagus.

Hamartomatous polyp of the cervical esophagus in a 60-year-old man was treated by local resection, and the patient did well. The histopathologic findings showed a predominance of cartilaginous tissue, but the specimen also contained glandular structures and adipose tissue. The diagnosis was choristoma or hamartoma. Review of the literature shows this to be the third case reported.

Esophageal Neoplasms↗