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M Jain

Publications and source records attributed to M Jain.

At least 145 records · Page 8Linked to original sources
PubMed1996

Intrinsic tone as potential vascular reserve in conductance and resistance vessels.

BACKGROUND: The purpose of this study was to define the degree of intrinsic tone in conductance and resistance vessels, to define the calcium dependency of intrinsic tone in these vascular preparations, and to investigate the efficacy of vasodilatory agents on the level of intrinsic tone in these vascular preparations. METHODS AND RESULTS: All vessels were deendothelialized. Isometric force was recorded from strips of ferret aorta, ferret pulmonary artery, and human coronary artery. Vessel diameter was recorded from the ferret epicardial coronary artery and from ferret coronary microvessel in a pressurized no-flow state. Intrinsic tone was defined as the active increase in force or decrease in diameter with warming from 6 degrees C to 37 degrees C. Changes in force or diameter with various pharmacological agents were expressed as a percentage of intrinsic tone. Our results indicate that intrinsic tone accounts for approximately 35% to 40% of total tone in all vascular preparations studied and is not dependent on extracellular calcium. Agents that increased cAMP levels (eg, forskolin, milrinone) and agents that decreased protein kinase C activity (eg, staurosporine) were partially effective in decreasing intrinsic tone. Nitroprusside, adenosine, hydralazine, and nifedipine had no significant effect. CONCLUSIONS: Our results indicate that intrinsic tone represents a significant component of vascular tone that has not been previously recognized and remains largely unexploited by current pharmacological therapies.

Animals↗
PubMed1996

Differences in risk factors for epithelial ovarian cancer by histologic type. Results of a case-control study.

A case-control study of associations between dietary and reproductive factors and cancer of the ovary was conducted during 1989-1992 in metropolitan Toronto and nearby areas of southern Ontario, Canada. In total, 450 women aged 35-79 years with histologically verified new primary epithelial ovarian cancers were interviewed concerning their reproductive history and dietary practices. Over the same time period, 564 randomly selected population controls, frequency-matched to the cases according to three 15-year age groups, were also interviewed. Continuous unconditional logistic regression methods were used for analysis. It was found that childbearing and use of oral contraceptives were associated with significant decreasing trends in the risk of epithelial ovarian cancer of all principal histologic types except mucinous tumors. For each full-term pregnancy, the odds ratio was 0.76 (95% confidence interval (CI) 0.69-0.85) for nonmucinous tumors and 1.03 (95% CI 0.88-1.21) for mucinous tumors; for each year of oral contraceptive use, the odds ratio was 0.89 (95% CI 0.85-0.93) for nonmucinous tumors and 0.98 (95% CI 0.93-1.04) for mucinous tumors (p = 0.00051 and p = 0.0040, respectively, for the difference in odds ratios between mucinous and nonmucinous tumors). Saturated fat intake also appeared to convey greater increased risk for women with mucinous tumors than for women with neoplasms of other histologic types (p = 0.029). Among women with nonmucinous tumors, increasing trends in risk of invasive serous cancer (p = 0.018), and particularly endometrioid cancer (p = 0.0041), were seen with use of noncontraceptive estrogens. Otherwise, borderline-malignant neoplasms seemed to have a similar spectrum of risk factor associations as invasive cancers. On the basis of this study and a number of others, the authors suggest that mucinous ovarian tumors may be etiologically unrelated to other types of epithelial tumors, and thus should be considered separately in studies of ovarian cancer.

Adult↗
PubMed1996

HIV epidemic in India.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Dietary assessment in epidemiology: comparison on food frequency and a diet history questionnaire with a 7-day food record.

The validity of two types of diet assessment methods, a self-administered food frequency questionnaire and and interviewer-administered detailed diet history, was assessed relative to a 7-day food record on a population- based sample of 95 men and 108 women in Toronto, Canada, between May 1989 and July 1990. Each study subject completed both questionnaire methods, a food frequency questionnaire and an interviewer-administered diet history, as well as a 7-day food record in a crossover design. Data were analyzed for both unadjusted and energy-adjusted nutrients to estimate Pearson's and intraclass correlations and agreement within the categories. Mean values for the intake of most nutrients assessed by the two questionnaire methods were similar. Average, energy-adjusted Pearson's correlation coefficients for men between a food frequency questionnaire and a 7-day food record were 0.55 for macronutrients and 0.48 for micronutrients compared with 0.47 for macro- and 0.48 for micronutrients between an interviewer-administered diet history and a 7-day food record. For women, they were 0.48 for macro- and 0.54 for micronutrients between a food frequency questionnaire and a 7-day food record and 0.46 and 0.49, respectively, between an interviewer-administered diet history and a 7-day food record. The energy-adjusted Pearson correlations were generally higher than were the energy-unadjusted Pearson correlations and the intraclass correlations. The present study suggests that a food frequency questionnaire is comparable with an interviewer-administered diet history as a predictor of nutrients as estimated form a 7-day food record.

Adult↗
PubMed1996

Induction of apoptosis by pyrrolidinedithiocarbamate and N-acetylcysteine in vascular smooth muscle cells.

Pyrrolidinedithiocarbamate (PDTC) and N-acetylcysteine (NAC) have been used as antioxidants to prevent apoptosis in lymphocytes, neurons, and vascular endothelial cells. We report here that PDTC and NAC induce apoptosis in rat and human smooth muscle cells. In rat aortic smooth muscle cells, PDTC induced cell shrinkage, chromatin condensation, and DNA strand breaks consistent with apoptosis. In addition, overexpression of Bcl-2 suppressed vascular smooth muscle cell death caused by PDTC and NAC. The viability of rat aortic smooth muscle cells decreased within 3 h of treatment with PDTC and was reduced to 30% at 12 h. The effect of PDTC and NAC on smooth muscle cells was not species specific because PDTC and NAC both caused dose-dependent reductions in viability in rat and human aortic smooth muscle cells. In contrast, neither PDTC nor NAC reduced viability in human aortic endothelial cells. The use of antioxidants to induce apoptosis in vascular smooth muscle cells may help prevent their proliferation in arteriosclerotic lesions.

Acetylcysteine↗
PubMed1996

Role of CD44 in the reaction of vascular smooth muscle cells to arterial wall injury.

CD44, the principal receptor for hyaluronic acid, is a widely distributed cell surface proteoglycan involved in cellular activation, proliferation, and migration. These processes are also central to the vascular smooth muscle cell's response to arterial wall injury. We evaluated the expression of CD44 and its isoform, CD44-V6, on vascular smooth muscle cells in vitro and in vivo and assessed the role of CD44 in DNA synthesis. Cultured vascular smooth muscle cells expressed CD44 and CD44-V6 at levels equal to or higher than those of the beta 1 and beta 2 integrins. In a rat carotid artery balloon injury model, CD44 and CD44-V6 mRNAs were unregulated in vascular smooth muscle cells after injury, and CD44 protein expression was greatest at the luminal edge of the growing neointima. CD44-expressing smooth muscle cells proliferated actively, and hyaluronic acid expression increased after injury in a temporal pattern similar to that of CD44. Through binding to hyaluronic acid, CD44 augmented DNA synthesis in cultured human and rat smooth muscle cells by 48 +/- 7.8 and 100 +/- 12.5%, respectively, an effect inhibited by an anti-CD44 antibody that blocked hyaluronate binding. These observations support a role for CD44 in the reaction of vascular smooth muscle cells to arterial wall injury.

Animals↗
PubMed1996

A mathematical model for concentration of blood affecting erythrocyte sedimentation.

The rate at which red blood cells fall in vitro is used as a common clinical test for a number of pathological conditions. But this test becomes unreliable when one finds flaws in the model under consideration and these doubts raise the issue of aggregation of the red blood cells in concentration whose mathematical analysis is relatively unknown. However Huang et al. (Biorheology 8, 157-163, 1971) made some efforts and their model resembles certain moving boundary problems. In the present work the modifications to this model have been suggested so far as the concentration of the blood is concerned, it being one of the important factors to decide ESR (Erythrocyte Sedimentation Rate). In the equation for nutrient concentration, to be more realistic, we have taken account of transfer of nutrient to the tissue from the blood. The exact solution has been obtained using Laplace transform. A finite element technique has been suggested which provides results closer to that of the exact solution. Our results for the blood concentration may be useful for conducting the ESR tests. A special case for an emergent patient when nutrient concentration falls down considerably and glucose is provided to improve the condition, has been shown graphically.

Blood Glucose↗
PubMed1996

Autologous bone marrow harvesting in outpatients.

STUDY OBJECTIVE: To assess the experience with autologous bone marrow harvesting in outpatients. DESIGN: Retrospective analysis of outpatients who underwent autologous bone marrow harvesting from 1990 to 1992. SETTING: University-affiliated surgical day hospital. SUBJECTS: 235 outpatients who underwent 264 autologous bone marrow harvests. Patients are candidates for autologous bone marrow harvesting on an outpatient basis if they are Karnofsky performance status of 80-100 and ASA status I, II or III. MEASUREMENTS AND MAIN RESULTS: The incidence of perioperative complications and hospital admission from the Surgical Day Hospital, the duration of the harvesting procedure and postanesthesia care unit (PACU) stay, details of the postoperative pain management, and costs and charges of the outpatient procedure compared with the same procedure performed on inpatients were assessed. Mean age was 37.7 years +/- 10.5 SD; + 7.7% patients were male and 52.3% were female. The disease process included non-Hodgkin's lymph/ma (30.3%), leukemia (24.3%), metastatic breast cancer (18.4%), Hodgkin's disease (17.3%), testicular carcinoma (6.5%) and other (1.6%). The patients were ASA status II (54.5%) or ASA III (45.5%) and received general endotracheal anesthesia. Each patient had 10.7 ml/kg +/- 2.8 SD of marrow harvested over a period of 110.7 minutes + 30.4 SD and total recovery room time of 233.7 minutes +/- 85.5 SD. Of 251 harvest, only three (1.1%) required hospital admission. PACU complaints included transient hypotension and dizziness (5.3%), nausea (3.8%), vomiting (3.4%), and (1.9%) temperature elevation. 83.7% of patients were reached at home the following day and 4.1% complained of nausea and/or vomiting at home. 6.8% of patients experienced temperature elevation at home. Only 27.1% of patients took the acetaminophen with codeine that was prescribed. The reminder required no opioid at home. Outpatient charge/ inpatient charge was 51.1%, and outpatient cost/inpatient was 74.4%. CONCLUSION: Autologous bone marrow harvesting is an acceptable ambulatory surgical procedure that results in a very law postanesthesia complication rate. Postoperative pain is easily controlled. The outpatient setting offers cost and time advantages to the patient.

Adult↗
PubMed1996

Recurrent thrombosis due to compound heterozygosity for factor V Leiden and factor V deficiency.

A point mutation in the factor V gene (factor V Leiden) is the most common cause of familial thrombophilia. Patients with factor V Leiden have an increased risk of thrombosis, particularly those homozygous for the mutation. However, the phenotype in individuals with the mutation is variable, suggesting that other factors influence thrombotic risk. We describe for the first time a family in which two independent defects in factor V co-exist: heterozygosity for factor V Leiden and factor V deficiency. Compound heterozygosity for these two defects results in a phenotype similar to a homozygous factor V Leiden state with profound resistance to APC and recurrent thrombosis.

Adult↗
PubMed1996

Secretory phospholipase A2 activity is required for permeability barrier homeostasis.

The extracellular bilayers which mediate the epidermal permeability barrier are enriched in ceramides, free fatty acids, and cholesterol. Yet, the epidermal lamellar body, the source of these lipids, is enriched in a more polar mixture; i.e., glucosylceramides and phospholipids, which it delivers to the stratum corneum (SC) interstices. Whereas the extracellular processing of glucosylceramides to ceramides has been shown to be required for barrier homeostasis, the requirement for phospholipid degradation to free fatty acids is not yet established. In this study, we ascertained that topical applications of two chemically unrelated inhibitors of secretory phospholipase A2 (PLA2), bromphenacyl bromide and MJ-33, produced a progressive perturbation in barrier function in intact murine skin, first appearing at 5 d, preceded by the development of epidermal hyperplasia. Moreover, the defect in barrier homeostasis could be reversed by topical co-applications of the nonessential fatty acid, and of palmitic acid, but not by linoleic acid, both products of phospholipid catabolism. Furthermore, the barrier abnormality was accompanied by a reduction in free fatty acid levels in the stratum corneum, while phospholipid levels remained unchanged. These biochemical alterations were accompanied by the appearance of immature, incompletely processed lamellar body-derived membranes in the SC interstices, and depletion of histochemically detectable neutral lipid. Both the abnormalities and the epidermal hyperplasia were reversed by co-applications of palmitic acid (but not linoleic acid) with either inhibitor. These results demonstrate that processing of phospholipids to nonessential free fatty acids, by a yet-to-be-identified extracellular phospholipase, is required for the maintenance of barrier homeostasis in intact skin. Furthermore, our studies show that the barrier abnormalities induced by the PLA2 inhibitors are due to a failure to generate free fatty acids rather than to phospholipid accumulation.

Acetophenones↗
PubMed1996

Childhood acute lymphoblastic leukaemia presenting as jaundice.

An unusual presentation of acute lymphoblastic leukaemia (ALL) in a 6-year-old girl is reported. She presented with unilateral cervical lymphadenopathy, a mixed obstructive/cholestatic jaundice and a progressive pancytopenia. Ultrasound examination revealed an obstructed common bile duct with gross thickening of the wall of the duct and intrahepatic bile duct dilatation. The jaundice resolved with high dose intravenous (i.v.) methylprednisolone. It is postulated that this was due to infiltration of the common bile duct, given the failure to demonstrate any other cause for the bile duct pathology.

Child↗