PubMed Health⌕ Search

Biomedical subjects

M K Patel

Publications and source records attributed to M K Patel.

At least 37 records · Page 2Linked to original sources
PubMed1998

Familial slipped capital femoral epiphysis: a report and considerations in management.

BACKGROUND: Familial inheritance of slipped capital femoral epiphysis (SCFE) is known. It has not been described in non-identical twins. A family where the mother and three of five siblings developed SCFE were investigated and managed. METHODS: Anthropometric measurement consisted of height-weight ratios. Serum sex hormone levels and bone Gla Protein was measured. Bone mineral densities were evaluated. RESULTS: The affected siblings had higher bodyweight percentiles. Other investigations were within normal limits. CONCLUSION: The unfavourable height-to-weight ratio was one of the mainstays in developing a management protocol for all siblings. The management protocol developed for the family is discussed.

Algorithms↗
PubMed1998

Ascorbate-mediated transplasma membrane electron transport in pulmonary arterial endothelial cells.

Pulmonary endothelial cells are capable of reducing certain electron acceptors at the luminal plasma membrane surface. Motivation for studying this phenomenon comes in part from the expectation that it may be important both as an endothelial antioxidant defense mechanism and in redox cycling of toxic free radicals. Pulmonary arterial endothelial cells in culture reduce the oxidized forms of thiazine compounds that have been used as electron acceptor probes for studying the mechanisms of transplasma membrane electron transport. However, they reduce another commonly studied electron acceptor, ferricyanide, only very slowly by comparison. In the present study, we examined the influence of ascorbate [ascorbic acid (AA)] and dehydroascorbate [dehydroascorbic acid (DHAA)] on the ferricyanide and thiazine reductase activities of the bovine pulmonary arterial endothelial cell surface. The endothelial cells were grown on microcarrier beads so that the reduction of ferricyanide and methylene blue could be studied colorimetrically in spectrophotometer cuvettes and in flow-through cell columns. The ferricyanide reductase activity could be increased 80-fold by adding DHAA to the medium, with virtually no effect on methylene blue reduction. The DHAA effect persisted after the DHAA was removed from the medium. AA also stimulated the ferricyanide reductase activity but was less potent, and the relative potencies of AA and DHAA correlated with their relative rates of uptake by the cells. The results are consistent with the hypothesis that AA is an intracellular electron donor for an endothelial plasma membrane ferricyanide reductase and that the stimulatory effect of DHAA is the result of increasing intracellular AA. Adding sufficient DHAA to markedly increase extracellular ferricyanide reduction had little effect on the plasma membrane methylene blue reductase activity, suggesting that pulmonary arterial endothelial cells have at least two separate transplasma membrane electron transport systems.

Animals↗
PubMed1998

Plasma c-erbB-2 levels in breast cancer patients: prognostic significance in predicting response to chemotherapy.

PURPOSE: To determine the significance of plasma c-erbB-2 levels to assess the extent of disease spread and to predict the response to chemotherapy in node-positive breast cancer patients. METHODS: We determined plasma levels of c-erbB-2 in 79 stages II and III breast cancer patients who received cyclophosphamide, methotrexate, and flourouracil (CMF)/cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) chemotherapy. All patients had a minimum follow-up of greater than 60 months or until disease recurrence. Plasma samples were obtained before and after chemotherapy. Plasma c-erbB-2 levels were quantified by enzyme-linked immunoassay. c-erbB-2 levels were analyzed in relation to the patients' axillary lymph node status, menopausal status, disease status, disease-free survival (DFS), and steroid receptor status of tumor. RESULTS: Plasma c-erbB-2 levels varied widely in breast cancer patients. In general, when all patients were included in the analyses, plasma c-erbB-2 levels before chemotherapy correlated significantly with the number of positive axillary lymph nodes and with postchemotherapy c-erbB-2 levels. No association was observed between pre- or postchemotherapy c-erbB-2 levels and other variables (patients' age at diagnosis, receptor status of the tumor, or disease status). The prognostic significance of different factors (ie, nodal status [one to three v > three positive nodes], menopausal status [pre- v postmenopausal women], estrogen receptor [ER] status [ER+ v ER-], and pre- and postchemotherapy c-erbB-2 levels) in predicting DFS was determined in all study patients. Among the variables examined, nodal status was the strongest predictor of DFS in these patients. The second most significant prognostic marker was postchemotherapy c-erbB-2 level. Prechemotherapy c-erbB-2 levels showed prognostic significance for DFS in a subset of breast cancer patients (ie, patients with > three positive nodes). Patients with greater than three positive lymph nodes and those with greater than 100 fmol/mL of plasma c-erbB-2 levels before therapy had significantly shorter DFS than did those patients with 100 fmol/mL or less c-erbB-2 levels. CONCLUSION: In breast cancer patients, determination of c-erbB-2 levels before therapy is an important biomarker to assess the extent of disease spread in the lymph nodes. Postchemotherapy c-erbB-2 levels are also a prognostic indicator for DFS in patients who receive chemotherapy. Finally, in a subgroup of patients with greater than three positive nodes, prechemotherapy c-erbB-2 levels are a prognostic marker for response of patients to standard chemotherapy.

Adult↗
PubMed1997

Inhibition of proliferation by heparin and expression of p53 in cultured human vascular smooth muscle cells.

Human vascular smooth muscle cells (HVSMC) cultured from restenotic lesions are resistant to inhibition of proliferation by heparin. We examined if altered expression of p53 protein might be related to this phenomenon. HVSMC were cultured from saphenous vein and p53 protein levels examined using immunocytochemistry, and by immunoprecipitation with antibodies specific for wild-type or mutant conformations followed by SDS PAGE and immunoblotting. Inhibition of proliferation by heparin was measured in 14-day growth assays. Elevated levels of p53 were found in five out of 41 HVSMC strains. The accumulated p53 protein was not precipitated by a mutant conformation-specific anti-p53 antibody in any of the five strains. In one of the five positive strains there was concomitant human cytomegaloviral infection. No significant difference was found between efficacy of heparin in the p53-positive and -negative strains. Furthermore heparin had no detectable effect on p53 protein levels. Although aberrant levels of p53 are detectable in a minority of HVSMC strains, these data do not support a role for altered p53 expression in resistance to the growth inhibitory effects of heparin in these cells.

Cell Division↗
PubMed1997

Church-based education: an outreach program for African Americans with hypertension.

The goals of this education outreach demonstration study were to prepare a cadre of registered nurses (RN) as Church Health Educators (CHE), and to test the efficacy of a hypertension (HBP) education and support program in African American (AA) churches for persons with HBP in managing blood pressure (BP). In this two-phase study, RNs were prepared as CHEs in phase 1 and a convenience sample of 97 subjects with HBP was taught by the CHEs in phase 2. The intervention's content included the bases of HBP and HBP management strategies, and was taught in eight 1-hour sessions. Using a pre-test-post-test design, data on knowledge, social support and BP were collected at baseline (pre), post-intervention (post1) and 3 months post-intervention (post2). Major findings include: (1) there was a significant increase in knowledge scores from pre to post1 and post2 (P < or = 0.0001; F = 95.08; df = 1.79); (2) education, age and number of years with HBP explained 49% of the variance associated with HBP knowledge; (3) systolic BP (SBP) and mean arterial BP (MAP) significantly decreased from pre to post1 and post2 (SBP-p < or = 0.0001, F = 18.35, df = 1.91; MAP-p < or = 0.0001, F = 17.80, df = 1.86); (4) DBP significantly decreased from pre to post1 only (p < or = 0.008, F = 17.48, df = 1.91); and (5) relationships were found between social support and DBP, and social support and MAP. Issues that emerged from this study with implications for outreach programming include recruitment and retention, randomization, selective sampling, intervention design and use of volunteers.

Adult↗
PubMed1997

Thrombospondin-1 is a potent mitogen and chemoattractant for human vascular smooth muscle cells.

Thrombospondin-1 (TSP-1) is a matricellular protein that is present in negligible amounts in normal human vasculature but occurs in significant amounts in diseased vessels. In this study, we examined the effect of TSP-1 on DNA synthesis, proliferation, and migration in human vascular smooth muscle cells grown from saphenous vein. TSP-1 (0.1 to 30 micrograms/mL) elicited a concentration-dependent increase in DNA synthesis under serum-free conditions. In combination with platelet-derived growth factor, TSP-1 induced a synergistic effect on DNA synthesis that was significantly higher than the additive effect of both agents. In proliferation assays, TSP-1 increased cell numbers by 50% relative to the serum-free controls over 14 days. In migration assays, conducted using modified Boyden chambers, TSP-1 (> or = 10 micrograms/mL) elicited marked chemotaxis to a degree equivalent to platelet-derived growth factor. The chemotactic response to TSP-1 (10 micrograms/mL) was abolished by the GRGDSP peptide but unaffected by the control GRGESP peptide, whereas neither peptide inhibited DNA synthesis stimulated by TSP-1. Inhibition of tyrosine kinase activity with genistein or tyrphostin A23 abolished DNA synthesis induced by TSP-1, and a neutralizing antibody to platelet-derived growth factor had no effect on DNA synthesis. Similarly, migration in response to TSP-1 was largely inhibited by these tyrosine kinase inhibitors. TSP-1 is a strong mitogen and chemoattractant for human vascular smooth muscle cells under serum-free conditions. The novel finding that TSP-1 is mitogenic for human cells contrasts with previous studies that have not shown any significant effect of TSP-1 itself on the growth of animal-derived smooth muscle cells. TSP-1 may play an important modulatory role in the local regulation of vascular smooth muscle function in vascular pathologies in humans.

Cell Division↗
PubMed1996

Effect of angiotension II on the expression of the early growth response gene c-fos and DNA synthesis in human vascular smooth muscle cells.

OBJECTIVES: The aims of this study were to characterize the angiotensin II receptor subtype present on vascular smooth muscle cells from human saphenous vein and to assess the effect of angiotensin II on the expression of the early growth response gene c-fos and on DNA synthesis. METHODS AND RESULTS: Using radioligand binding studies, we have defined the angiotensin II receptors present on these cells as being predominantly of the AT1 subtype. Angiotensin II increased peak intracellular calcium levels by 126 +/- 16 nmol/l (mean +/- SEM) in 17/49 cultures. Angiotensin II induced c-fos expression in a concentration-dependent manner only in cultures that exhibited an intracellular calcium transient in response to stimulation with angiotensin II. The induction of c-fos was inhibited by the selective AT1 antagonist losartan in accordance with the binding studies. Angiotensin II stimulated DNA synthesis with a maximal increase of 66.4% +/- 20.5% over serum-free levels at 1 nmol/l (mean +/- SEM, n = 6, P < 0.05). DNA synthesis declined with increasing angiotensin II concentration, falling to control values at 1 mumol/l, suggesting that a growth-inhibitory influence may counter-balance the stimulatory effect that is observed at lower concentrations. CONCLUSION: Vascular smooth muscle cells from human saphenous vein possess predominantly AT1 receptors and in response to angiotensin II show an induction of c-fos and a modest increase in DNA synthesis.

Angiotensin II↗
PubMed1995

Inhibition of human vascular smooth muscle cell proliferation by the novel multiple-action antihypertensive agent carvedilol.

We examined the antiproliferative effect of the novel multiple-action antihypertensive agent carvedilol on human vascular smooth muscle cells (VSMC). Carvedilol inhibited the increase in cell number induced by foetal calf serum (FCS) in 86% (18 of 21) of human VSMC grown both from saphenous vein (17.6 +/- 3.5% inhibition, mean +/- SEM, n = 15) and restenotic lesions (31.4 +/- 5.5% inhibition, mean +/- SEM, n = 5). Carvedilol had a greater antiproliferative effect than other beta-adrenoceptor antagonists. In comparison with calcium channel blockers, carvedilol (10 microM) elicited a degree of growth inhibition similar to that of verapamil, but was less effective than the dihydropyridine amlodipine at equimolar concentrations. Although carvedilol had a greater antiproliferative effect on cells derived from restenotic lesions cells than on control saphenous vein cells, the difference was not statistically significant. In the present study, the antiproliferative effect of carvedilol on human VSMC in vitro occurred at concentrations higher than those in plasma. Although this may represent a limitation to the clinical efficacy of carvedilol against proliferation of VSMC associated with hypertension and atherosclerosis, the apparent relative selectivity of carvedilol for restenosis-derived cells is a promising line of investigation.

Antihypertensive Agents↗
PubMed1993

A FORTRAN program for the statistical analysis of incomplete time series data sets by a method of partition.

A program written in FORTRAN-77 which executes an analysis for periodicity of a time series data set is presented. Time series analysis now has applicability and use in a wide range of biomedical studies. The analytical method termed here a method of partition is derived from periodogram analysis, but uses the principle of analysis of variance (ANOVA). It is effective when used on incomplete data sets. An example in which a data set is made progressively more incomplete by the random removal of values demonstrates this, and a listing of the program and a sample output in both an abbreviated and a full version are given.

Analysis of Variance↗
PubMed1992

Effects of cannabinoids and cocaine on the mitogen-induced transformations of lymphocytes of human and mouse origins.

The effects of delta 9-tetrahydrocannabinol (d9THC), delta 6-tetrahydrocannabinol (d6THC), and cocaine on the mitogen-induced transformations of lymphocytes of human and mouse origins were examined in an in vitro system. None of the three compounds is mitogenic in nature. The effects of the two components of marijuana on the mitogen-induced transformation are biphasic. Both compounds stimulated the lymphocyte transformation at low concentrations and inhibited mitogenesis at high concentrations. Cocaine, on the other hand, neither affected mitogen-induced lymphocyte transformations nor altered d9THC's transformation effects when both compounds were added together. Human lymphocytes and mouse splenocytes appeared to respond in similar patterns.

Animals↗
PubMed1991

Development and evaluation of the Osteoporosis Health Belief Scale.

The Osteoporosis Health Belief Scale was developed to measure health beliefs related to osteoporosis. It is a 35-item self-report questionnaire based on the Health Belief Model which is specifically designed to assess beliefs related to exercise behaviors and calcium intake of elderly subjects. The instrument consists of seven subscales: Seriousness, Susceptibility, Health Motivation, Calcium Benefits, Calcium Barriers, Exercise Benefits, and Exercise Barriers. The instrument was tested on a sample of 150 elderly individuals. The psychometric properties of the scales are discussed along with recommendations for its use in research and practice.

Aged↗
PubMed1991

Colonic strictures following successful medical management of necrotizing enterocolitis: a prospective study evaluating early gastrointestinal contrast studies.

This is a prospective study of 50 patients with neonatal necrotizing enterocolitis (NEC) treated successfully by medical means. They were all screened with an upper gastrointestinal (GI) contrast study after 14 days of healing and prior to establishment of feeding. Thirty-six patients (72%) with normal upper GI examinations responded well to a graduated increase in feeding. Another 5 (10%) with questionable areas on their upper GI examination had a normal follow-up contrast enema. Feeding was successfully established in this group of infants also. The remaining 9 patients (18%) had demonstrable strictures in both contrast studies. After elective resection of strictures with restoration of intestinal continuity, they were also fed successfully. No delayed strictures were seen in any of the patients. We propose that this method of evaluation is safe, efficient and reliable in the diagnosis of strictures that develop in patients recovering from NEC.

Colonic Diseases↗