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Biomedical subjects

V Bansal

Publications and source records attributed to V Bansal.

At least 19 recordsLinked to original sources

Diabetic neuropathy.

Diabetic neuropathy (DN) refers to symptoms and signs of neuropathy in a patient with diabetes in whom other causes of neuropathy have been excluded. Distal symmetrical neuropathy is the commonest accounting for 75% DN. Asymmetrical neuropathies may involve cranial nerves, thoracic or limb nerves; are of acute onset resulting from ischaemic infarction of vasa nervosa. Asymmetric neuropathies in diabetic patients should be investigated for entrapment neuropathy. Diabetic amyotrophy, initially considered to result from metabolic changes, and later ischaemia, is now attributed to immunological changes. For diagnosis of DN, symptoms, signs, quantitative sensory testing, nerve conduction study, and autonomic testing are used; and two of these five are recommended for clinical diagnosis. Management of DN includes control of hyperglycaemia, other cardiovascular risk factors; alpha lipoic acid and L carnitine. For neuropathic pain, analgesics, non-steroidal anti-inflammatory drugs, antidepressants, and anticonvulsants are recommended. The treatment of autonomic neuropathy is symptomatic.

Aldehyde Reductase↗

Methylenetetrahydrofolate reductase gene polymorphism in Indian stroke patients.

BACKGROUND AND AIMS: In view of the prevailing controversy about the role of Methylenetetrahydrofolate reductase (MTHFR) C677T mutation in stroke and paucity of studies from India, this study has been undertaken to evaluate MTHFR C677T gene polymorphism in consecutive ischemic stroke patients and correlate these with folic acid, homocysteine (Hcy) and conventional risk factors. SETTINGS AND DESIGN: Ischemic stroke patients prospectively evaluated in a tertiary care teaching hospital. MATERIALS AND METHODS: Computerized tomography proven ischemic stroke patients were prospectively evaluated including clinical, family history of stroke, dietary habits and addictions. Their fasting and postprandial blood sugar, lipid profile, vitamin B12, folic acid and MTHFR gene analysis were done. STATISTICAL ANALYSIS: MTHFR gene polymorphism was correlated with serum folic acid, Vitamin B12 and Hcy levels; family history of stroke in first-degree relatives; and dietary habits; employing Chi-square test. RESULTS: There were 58 patients with ischemic stroke, whose mean age was 50 (4-79) years; among them, 10 were females. MTHFR gene polymorphism was present in 19 (32.8%) patients, 3 were homozygous and 16 were heterozygous. Both serum folate and B12 levels were low in 29 (50%) patients and Hcy in 48 (83%). Hypertension was present in 28 (48%) patients, diabetes in 12 (21%), hyperlipidemia in 52 (90%), smoking in 17 (29%), obesity in 1 (1.7%) and family history of stroke in first-degree relatives in 13 (22.4%). There was no significant relationship of MTHFR gene polymorphism with folic acid, B12, Hcy levels, dietary habits and number of risk factors. Vitamin B12 level was low in vegetarians (P<0.003). In 3 patients with MTHFR TT alleles, Hcy was elevated in all 3, low folic acid in 2 and family history of stroke in 1 patient. CONCLUSION: MTHFR gene polymorphism was found in one-third of patients with ischemic stroke and was insignificantly associated with higher frequency of elevated Hcy.

Adolescent↗

Thrombosed hemodialysis grafts: lyse and wait with tissue plasminogen activator or urokinase compared to mechanical thrombolysis with the Arrow-Trerotola Percutaneous Thrombolytic Device.

PURPOSE: To determine if the lyse and wait (L&W) technique with a 4-mg dose of alteplase (tissue plasminogen activator; tPA) is a safe and effective method of declotting dialysis grafts as compared to use of the Arrow-Trerotola Percutaneous Thrombectomy Device (PTD) or the L&W technique with use of urokinase (UK). MATERIALS AND METHODS: Forty patients were randomized prospectively to undergo L&W declotting with use of 4 mg of tPA or mechanical thrombolysis with the PTD. The time interval to restored graft flow, total procedure time, hemostasis time, and anatomic success, clinical success, complications, and patency rates were analyzed. These were compared with historic results in 20 patients treated with the L&W technique with use of 250,000 U UK. RESULTS: The immediate anatomic success rate was 95% in the tPA L&W and PTD groups. The mean in-room lysis time with restored flow was 10 minutes for L&W with tPA and 19 minutes for PTD (P = .002). The mean in-room procedure time was 39 minutes for L&W and 45 minutes for PTD (P = NS). Mean hemostasis time with use of manual compression was 44 minutes for L&W with tPA and 23 minutes for PTD (P = .057). The historic group of 20 patients who underwent L&W with UK had a 95% anatomic success rate, a mean of 14 minutes of lysis time, a mean of 34 minutes of procedure time, and a mean of 26 minutes of time to hemostasis. No bleeding complications occurred in the PTD group. Seven episodes of bleeding occurred in six patients given tPA; four were delayed 60-90 minutes after the procedure, one necessitated hospitalization, and two required additional therapies. Four of the 20 patients undergoing L&W with UK had minor puncture site bleeding during the procedure. The 3-month primary patency rates were 65%, 65%, and 60% for L&W with tPA, PTD, and L&W with UK, respectively (P = NS). CONCLUSION: The 4-mg dose of tPA is effective but results in more bleeding complications and longer hemostasis times than mechanical thrombolysis with use of the PTD. Unlike in our experience with UK, bleeding complications with tPA were both major and delayed.

Blood Vessel Prosthesis↗

A look at the safety profile of over-the-counter naproxen sodium: a meta-analysis.

As the trend for Americans to self-medicate continues to increase, it becomes important to review the safety of over-the-counter (OTC) medications. This article will review the safety of an OTC analgesic, Aleve (naproxen sodium). The objective of this meta-analysis is to evaluate the frequency of occurrence of all adverse events in subjects taking various doses of OTC naproxen sodium as compared to placebo. These varying doses and dosage regimens were studied individually and consisted of 220 to 880 mg administered in single, multiple, and PRN (as needed) doses of naproxen sodium. This meta-analysis confirmed the favorable safety profile of naproxen sodium at OTC doses and established that the overall occurrence of adverse events with naproxen sodium was comparable and in some cases significantly lower than placebo. These results indicate that treatment with naproxen sodium may be highly beneficial from a clinical and economical perspective and safe when adhering to labeled directions.

Adverse Drug Reaction Reporting Systems↗

Role of stress-activated mitogen-activated protein kinase (p38) in beta 2-integrin-dependent neutrophil adhesion and the adhesion-dependent oxidative burst.

Bacterial LPS elicits both rapid activation of the stress-activated MAP kinase p38 in polymorphonuclear leukocytes (PMN) and rapid adhesion of the PMN to ligands for the leukocyte integrin CD11b/CD18. The functional correlation between these two events was examined. The time course for tyrosine phosphorylation of p38 in PMN in response to 10 ng/ml LPS in 1% normal human serum was consistent with participation in signaling for leukocyte integrin-dependent adhesion, with transient phosphorylation peaking at 10 to 20 min. The concentration dependence of p38 phosphorylation also resembled that for PMN adhesion, with <1 ng/ml LPS eliciting a response. Phosphorylation was inhibited by mAb 60b against CD14, but not by mAb 26ic, a nonblocking anti-CD14. The function of p38 in integrin-dependent adhesion and the adhesion-dependent oxidative burst was tested using a specific inhibitor of p38, SB203580. SB203580 inhibited adhesion by diminishing the initial rate of adherence in response to both LPS and TNF, with a half-maximal concentration in the range of 0.1 to 0.6 microM. It did not, however, block adhesion in response to formyl peptide or PMA. The p38 inhibitor also blocked the adhesion-dependent oxidative burst with a half-maximal concentration similar to that for adhesion. Timed delivery of the compound during the lag phase preceding H2O2 production suggested that p38 kinase activity was required throughout the lag but not after the oxidase was assembled. These results suggest that p38 functions in PMN to signal leukocyte integrin-dependent adhesion and the subsequent massive production of reactive oxygen intermediates.

CD18 Antigens↗

Simulated glomerular hypertension promotes mesangial cell apoptosis and expression of cathepsin-B and SGP-2.

BACKGROUND: Focal glomerulosclerosis (FGS) is characterized by the accumulation of mesangial matrix and lack of mesangial cells (MC). We studied the role of glomerular hypertension (GH) in the development of MC hypoplasia. METHODS: We used an in vitro model of GH to study the effect of GH on MC apoptosis. Cultured rat endothelial cells were grown in the intracapillary space and MCs were grown in the extracapillary space. MC proliferation as well as apoptosis was evaluated under simulated normal glomerular pressure (SNGP) as well as simulated glomerular hypertension (SGH). Apoptosis was determined morphologically by DNA fragmentation using Hoechst staining as well as with the use of DNA gel electrophoresis. MCs grown under SNGP and SGH were also evaluated for the expression of genes associated with active cell death. In addition, we evaluated the effect of direct applied pressure on MC apoptosis. RESULTS: MCs grown under SGH were less elliptical and had a tendency to develop a dome in the center. Direct applied pressure promoted MC apoptosis in a dose and time dependent manner. DNA gel electrophoresis from MCs grown under SGH also showed integer multiples of 180 base pairs (ladder pattern); whereas cells grown under SNGP showed no DNA fragmentation. SGH increased mRNA expression of cathepsin-B (SNGP, 0.31 +/- 0.04 vs SGH, 0.57 +/- 0.03, P < 0.01, n = 3) and SGP-2 (SNGP, 0.55 +/- 0.05 vs SHG, 1.08 +/- 0.12, P < 0.01, n = 3) in MCs when compared to cells grown under SNGP. CONCLUSIONS: The present in vitro study suggests that GH has the potential to convert a hypercellular mesangium into a hypocellular one. This effect of GH is associated with expression of genes associated with active cell death.

Animals↗

A novel polymorphism of FcgammaRIIIa (CD16) alters receptor function and predisposes to autoimmune disease.

A novel polymorphism in the extracellular domain 2 (EC2) of FcgammaRIIIA affects ligand binding by natural killer (NK) cells and monocytes from genotyped homozygous normal donors independently of receptor expression. The nonconservative T to G substitution at nucleotide 559 predicts a change of phenylalanine (F) to valine (V) at amino acid position 176. Compared with F/F homozygotes, FcgammaRIIIa expressed on NK cells and monocytes in V/V homozygotes bound more IgG1 and IgG3 despite identical levels of receptor expression. In response to a standard aggregated human IgG stimulus, FcgammaRIIIa engagement on NK cells from V/V (high-binding) homozygotes led to a larger rise in [Ca2+]i, a greater level of NK cell activation, and a more rapid induction of activation-induced cell death (by apoptosis). Investigation of an independently phenotyped normal cohort revealed that all donors with a low binding phenotype are F/F homozygotes, while all phenotypic high binding donors have at least one V allele. Initial analysis of 200 patients with SLE indicates a strong association of the low binding phenotype with disease, especially in patients with nephritis who have an underrepresentation of the homozygous high binding phenotype. Thus, the FcgammaRIIIa polymorphism at residue 176 appears to impact directly on human biology, an effect which may extend beyond autoimmune disease characterized by immune complexes to host defense mechanisms.

Antibody-Dependent Cell Cytotoxicity↗

Differential responses of ovine intrapulmonary arteries and veins to acetylcholine.

We compared the effects of acetylcholine (Ach) in intrapulmonary arteries and veins of adult sheep. Preconstricted arterial rings with endothelium relaxed with Ach whereas arteries without endothelium or pretreated with NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, did not dilate. Venous rings with or without endothelium, whether under resting tension or preconstricted, always contracted with Ach. However, preconstricted veins dilated with bradykinin, another endothelium-dependent vasodilator. Preconstricted veins pretreated with indomethacin or SQ29548, a prostaglandin H2 (PGH2)/TxA2 receptor blocker, did not constrict but rather dilated with Ach. This dilation was abolished with removal of endothelium or treatment with L-NAME, indicating that endothelium-derived NO (EDNO) was mediating the dilation. We conclude that Ach is an endothelium-dependent vasodilator in ovine intrapulmonary arteries, whereas in veins, Ach elicits two responses: EDNO-mediated vasodilation and vasoconstriction mediated by TxA2/PGH2.

Acetylcholine↗

Vasoactive agents modulate matrix metalloproteinase-2 activity by mesangial cells.

Vasoactive agents alter proteinuria by modulating glomerular hemodynamics. The authors hypothesized that vasoactive agents may be altering degradation of the collagen component of glomerular basement membrane, which also may be contributing to proteinuria. Mesangial cells treated with 10(-6) M angiotensin II had higher (P < 0.01) metalloproteinase activity (MA) when compared with control cells. This effect of angiotensin II was dose dependent. Amlodipine (10(-6) M), a calcium channel blocker, inhibited MA (control, 5.86 +/- 0.08 microgram versus 4.13 +/- 0.06 microgram gelatin degraded/mg protein, P < 0.001). The decrease in mesangial MA caused by amlodipine also occurred in a dose dependent manner. Amlodipine attenuated (P < 0.05) angiotensin II-stimulated MA (control, 6.69 +/- 0.30 micrograms, angiotensin II, 10.68 +/- 0.49 micrograms, angiotensin II+amlodipine 8.29 +/- 0.30 micrograms gelatin degraded/mg protein). Prostaglandin E2 increased (P < 0.001) MA (control, 10.22 +/- 0.9 micrograms versus prostaglandin E2, 17.9 +/- 0.9 micrograms gelatin degraded/mg protein), whereas indomethacin, a prostaglandin inhibitor, attenuated the metalloproteinase activity (control, 9.67 +/- 0.32 micrograms vs. 10(-6) M indomethacin, 4.22 +/- 0.31 micrograms gelatin degraded/mg protein, P < 0.001). Indomethacin also inhibited angiotensin II-stimulated MA (angiotensin II, 18.66 +/- 0.46 vs. angiotensin II+indomethacin, 11.86 +/- 0.56 micrograms degraded/mg protein, P < 0.001). Similarly, meclofenamate, another prostaglandin inhibitor, attenuated (P < 0.001) angiotensin II-induced MA. Because angiotensin II increases prostaglandin E2 synthesis by mesangial cells, it appears that increased MA, induced by angiotensin II, may be mediated partly through the generation of prostaglandin E2.

Amlodipine↗