20 research outputs found

    RELIABLE AUTOMATED NEEDLE INSERTION SYSTEM FOR MEDICAL APPLICATION

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    Many disorders occur annually as a result of poorly performed stings. This project is an attempt to develop a system that automates blood tests, serum injections and catheter placements, and to identify its basic limitations. Determining parameters are first identified. They include the coordinates of stinging point on the skin, the depth of blood vessel, its radius and the age of patient. The developed module performs the sting process based on the knowledge of these parameters. Automation is based on a neural network which correlates the data to determine insertion angle and needle geometry. Though the insertion process is adapted to patient profile, difficulties still remain concerning correct skin viscoelastic properties as proper input parameters. However, finer analysis of skin-needle system indicates the possibility of a secure and much easier automated sting in a large range of usual parameters with constant speed

    Gene Deletion of the Kinin Receptor B1 Attenuates Cardiac Inflammation and Fibrosis During the Development of Experimental Diabetic Cardiomyopathy

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    Objective: Diabetic cardiomyopathy is associated with increased mortality in patients with diabetes mellitus. The underlying pathology of this disease is still under discussion. We studied the role of the kinin B1 receptor on the development of experimental diabetic cardiomyopathy. Research Design and Methods: We utilized B1 receptor knockout mice and investiged cardiac inflammation, fibrosis and oxidative stress after induction of streptozotocin (STZ)-induced diabetes mellitus. Furthermore, the left ventricular function was measured by pressure-volume loops after 8 weeks of diabetes mellitus. Results: B1 receptor knockout mice showed an attenuation of diabetic cardiomyopathy with improved systolic and diastolic function in comparison with diabetic control mice. This was associated with a decreased activation state of the MAP kinase p38, less oxidative stress as well as normalized cardiac inflammation, shown by fewer invading cells and, no increase in matrix metalloproteinase-9 as well as the chemokine CXCL-5. Furthermore, the pro-fibrotic connective tissue growth factor was normalized, leading to a reduction in cardiac fibrosis despite severe hyperglycemia in mice lacking the B1 receptor. Conclusion: These findings suggest that the B1 receptor is detrimental in diabetic cardiomyopathy in that it mediates inflammatory and fibrotic processes. These insights might have useful implications on future studies utilizing B1 receptor antagonists for treatment of human diabetic cardiomyopathy

    Kinin B1 Receptor Enhances the Oxidative Stress in a Rat Model of Insulin Resistance: Outcome in Hypertension, Allodynia and Metabolic Complications

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    BACKGROUND: Kinin B(1) receptor (B(1)R) is induced by the oxidative stress in models of diabetes mellitus. This study aims at determining whether B(1)R activation could perpetuate the oxidative stress which leads to diabetic complications. METHODS AND FINDINGS: Young Sprague-Dawley rats were fed with 10% D-Glucose or tap water (controls) for 8-12 weeks. A selective B(1)R antagonist (SSR240612) was administered acutely (3-30 mg/kg) or daily for a period of 7 days (10 mg/kg) and the impact was measured on systolic blood pressure, allodynia, protein and/or mRNA B(1)R expression, aortic superoxide anion (O(2)(*-)) production and expression of superoxide dismutase (MnSOD) and catalase. SSR240612 reduced dose-dependently (3-30 mg/kg) high blood pressure in 12-week glucose-fed rats, but had no effect in controls. Eight-week glucose-fed rats exhibited insulin resistance (HOMA index), hypertension, tactile and cold allodynia and significant increases of plasma levels of glucose and insulin. This was associated with higher aortic levels of O(2)(*-), NADPH oxidase activity, MnSOD and catalase expression. All these abnormalities including B(1)R overexpression (spinal cord, aorta, liver and gastrocnemius muscle) were normalized by the prolonged treatment with SSR240612. The production of O(2)(*-) in the aorta of glucose-fed rats was also measured in the presence and absence of inhibitors (10-100 microM) of NADPH oxidase (apocynin), xanthine oxidase (allopurinol) or nitric oxide synthase (L-NAME) with and without Sar[D-Phe(8)]des-Arg(9)-BK (20 microM; B(1)R agonist). Data show that the greater aortic O(2)(*-) production induced by the B(1)R agonist was blocked only by apocynin. CONCLUSIONS: Activation of kinin B(1)R increased O(2)(*-) through the activation of NADPH oxidase in the vasculature. Prolonged blockade of B(1)R restored cardiovascular, sensory and metabolic abnormalities by reducing oxidative stress and B(1)R gene expression in this model

    The complexities of the cardiovascular actions of cannabinoids

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    The cardiovascular actions of cannbinoids are complex. In general they cause vasorelaxation in isolated blood vessels, while in anaesthetised animals they cause multiphasic responses which involve an early bradycardia and long-lasting hypotension. However, in conscious animals, the picture is one of bradycardia followed by pressor responses. Clearly, the responses to cannabinoids are dependent on the experimental conditions and synthetic cannabinoids and endocannabinoids exhibit different pharmacologies. In terms of mechanisms involved in the vascular responses to cannabinoids, the following have been implicated: the involvement of ‘classical' cannabinoid receptors, the involvement of a novel endothelial cannabinoid receptor, the release of nitric oxide, the release of endothelium-derived hyperpolarising factor (EDHF), the activation of vanilloid receptors, metabolism of endocannabinoids to vasoactive molecules, and both peripheral inhibition and central excitation of the sympathetic nervous system

    Loss of Bradykinin Signaling Does Not Accelerate the Development of Cardiac Dysfunction in Type 1 Diabetic Akita Mice

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    Bradykinin signaling has been proposed to play either protective or deleterious roles in the development of cardiac dysfunction in response to various pathological stimuli. To further define the role of bradykinin signaling in the diabetic heart, we examined cardiac function in mice with genetic ablation of both bradykinin B1 and B2 receptors (B1RB2R−/−) in the context of the Akita model of insulin-deficient type 1 diabetes (Ins2Akita/+). In 5-month-old diabetic and nondiabetic, wild-type and B1RB2R−/− mice, in vivo cardiac contractile function was determined by left-ventricular (LV) catheterization and echocardiography. Reactive oxygen species levels were measured by 2′-7′-dichlorofluorescein diacetate fluorescence. Mitochondrial function and ATP synthesis were determined in saponin-permeabilized cardiac fibers. LV systolic pressure and the peak rate of LV pressure rise and decline were decreased with diabetes but did not deteriorate further with loss of bradykinin signaling. Wall thinning and reduced ejection fractions in Akita mouse hearts were partially attenuated by B1RB2R deficiency, although other parameters of LV function were unaffected. Loss of bradykinin signaling did not increase fibrosis in Ins2Akita/+ diabetic mouse hearts. Mitochondrial dysfunction was not exacerbated by B1RB2R deficiency, nor was there any additional increase in tissue levels of reactive oxygen species. Thus, loss of bradykinin B2 receptor signaling does not abrogate the previously reported beneficial effect of inhibition of B1 receptor signaling. In conclusion, complete loss of bradykinin expression does not worsen cardiac function or increase myocardial fibrosis in diabetes

    Bradykinin receptor 1 activation exacerbates experimental focal and segmental glomerulosclerosis

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    Focal and segmental glomerulosclerosis (FSGS) is one of the most important causes of end-stage renal failure. the bradykinin B1 receptor has been associated with tissue inflammation and renal fibrosis. To test for a role of the bradykinin B1 receptor in podocyte injury, we pharmacologically modulated its activity at different time points in an adriamycin-induced mouse model of FSGS. Estimated albuminuria and urinary protein to creatinine ratios correlated with podocytopathy. Adriamycin injection led to loss of body weight, proteinuria, and upregulation of B1 receptor mRNA. Early treatment with a B1 antagonist reduced albuminuria and glomerulosclerosis, and inhibited the adriamycin-induced downregulation of podocin, nephrin, and alpha-actinin-4 expression. Moreover, delayed treatment with antagonist also induced podocyte protection. Conversely, a B1 agonist aggravated renal dysfunction and even further suppressed the levels of podocyte-related molecules. Thus, we propose that kinin has a crucial role in the pathogenesis of FSGS operating through bradykinin B1 receptor signaling. Kidney International (2011) 79, 1217-1227; doi:10.1038/ki.2011.14; published online 16 March 2011Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INCT Complex FluidsUniv São Paulo, Inst Biomed Sci 4, Dept Immunol, Lab Imunobiol Transplante, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Nefrol, Dept Med, Lab Imunol Clin & Expt, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Nefrol, Dept Med, Mol Biol Lab, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Patol, BR-04023900 São Paulo, BrazilUniv Paris 07, INSERM, U699, Paris, FranceUniv São Paulo, Dept Patol, BR-05508900 São Paulo, BrazilHosp Israelita Albert Einstein, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Nefrol, Dept Med, Lab Imunol Clin & Expt, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Disciplina Nefrol, Dept Med, Mol Biol Lab, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Patol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023900 São Paulo, BrazilFAPESP: 04/08226-9FAPESP: 07/07139-3FAPESP: 2007/07120FAPESP: 08/55125-4CNPq: 501848/2009-6Web of Scienc
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