2,197 research outputs found
The complexity of platlet metabolism and its contribution to atherotrombosis
No full textActa Cardiol. 2009 Apr;64(2):157-65.
The complexity of platelet metabolism and its contribution to atherothrombosis.
Puddu P, Muscari A, Puddu GM, Cravero E, Giannoni C, Zoli M.
Department of Internal Medicine, Ageing and Nephrological Diseases, University of Bologna and S. Orsola-Malpighi Hospital, Bologna, Italy.
Platelet functions are multiple, complex and not limited to haemostasis. In fact, platelets play a relevant role in vascular inflammation and atherosclerosis (ATS). In the presence of vascular lesions or inflammation, endothelial denudation or activation triggers mechanisms that render the circulating platelets adhesive for the vascular wall. Endothelial lesions expose subendothelial matrix components, such as collagen, von Willebrand factor, fibronectin and other adhesive proteins. Platelet adhesion depends on the interaction between these components and platelet receptors (mainly glycoprotein (GP) VI and GPlb-IX-V). Adhesion triggers the platelet release of inflammatory and mitogenic substances that alter the thromboresistant endothelial surface, enhance the chemoattraction of leukocytes, stimulate smooth muscle cell proliferation and contribute to matrix degradation. Finally, GPIIb-IIIa receptors are activated, leading to firm platelet aggregation and thrombus formation. Platelets participate in the formation of mural thrombi in the late stages of atherosclerotic disease, but also adhere to endothelial cells during the earlier stages of atherosclerotic plaque development. Moreover, platelets exert important functions in modulating inflammatory and immune processes. An improved comprehension of the complex platelet pathophysiology could suggest new therapeutic strategies to reduce the impact of atherosclerotic disease.
PMID: 19476106 [PubMed - indexed for MEDLINE
O Estudo da osteotomia valgizante proximal de tíbia com placa "calço" de puddu.
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Clínica Cirúrgica, Curso de Medicina, Florianópolis, 200
Mitochondrial dysfunction as an initiating event in atherogenesis - a plausible hypothesis
No full text
Usefulness of coronary flow reserve measured by echocardiography to improve the identification of significant left anterior descending coronary artery stenosis assessed by multi detector computed tomography.
No full textMultidetector computed tomography (MDCT) detects coronary artery disease. However, an overestimation of coronary artery stenosis and artifacts can prevent accurate identification of significant coronary narrowing. The combination of MDCT with coronary flow reserve (CFR), the hyperemic/baseline peak flow velocity ratio, measured by transthoracic Doppler echocardiography might be helpful. We studied 144 consecutive patients with CFR and quantitative coronary angiography, obtained using both MDCT and invasive coronary angiography (reference method). It was hypothesized that the CFR might provide an incremental value to MDCT in detecting significant (> or =70%) left anterior descending (LAD) coronary artery stenosis. A CFR cutoff of <2 was used to discriminate significant stenosis. CFR was feasible in 141 (98%) of 144 patients, and MDCT was feasible in 131 (91%) of 144 patients (p <0.02). In a univariate model, the prediction of significant LAD stenosis was slightly, but significantly (p <0.0001), better with CFR (sensitivity 90%, specificity 96%, positive predictive value 84%, negative predictive value 97%, and diagnostic accuracy 94%, chi-square = 97.5) than with MDCT (sensitivity 80%, specificity 93%, positive predictive value 71%, negative predictive value 95%, diagnostic accuracy 90%, chi-square = 63.2). When the findings from transthoracic Doppler echocardiography and MDCT agreed, the diagnostic accuracy increased (96%; chi-square = 86.1, p <0.0001). In a multivariate prediction of significant LAD stenosis using a logistic neural network, CFR overshadowed MDCT, and the area under the receiver operating curve was 0.99. Of the 13 patients missed by MDCT, the diagnostic accuracy of transthoracic Doppler echocardiography to predict significant LAD stenosis was 100%. Thus, CFR could improve the diagnostic accuracy of MDCT to detect significant LAD stenosis
Association of serum C3 and essential hypertension
No full textThis study was performed to assess the possible involvement of humoral immunity in essential hypertension, independently of the presence of atherosclerotic disease, which in turn may be associated with immunologic changes. Sixty-five patients without demonstrated atherosclerotic disease were selected according to clinical and arteriographic criteria, including 23 hypertensive subjects (all pharmacologically treated) and 42 controls. Mean ages (58.7 +/- 8.3(1 S.D.) years in the controls and 57.7 +/- 7.9 years in the hypertensive subjects) and sex distribution were similar in the 2 groups. Of the main risk factors, atherosclerosis, smoking, diabetes, total cholesterol and HDL-cholesterol were equivalent, while triglycerides were higher in the hypertensive subjects than in the controls (142.6 +/- 52.7 vs. 112.6 +/- 67.7 mg/dl; p = 0.0065). In these subjects' sera the immunoglobulins IgG, IgA and IgM, and the third and fourth complement components (C3 and C4) were measured. Of these variables, only C3 was higher in the hypertensive subjects than in the controls (124.3 +/- 29.3 vs. 107.8 +/- 18.4 mg/dl; p = 0.0183). Furthermore, C3 was significantly correlated with triglycerides (tau = 0.3613; p < 0.0001), but the association with hypertension was confirmed only for C3, and not for triglycerides, by multiple logistic regression (p = 0.0142). The increase in serum C3 suggests the possible implication of humoral immunity in the pathogenesis or progression of essential hypertension
Jumper's knee
No full textAbstract The authors present a clinical study on twenty six cases of a painful syndrome affecting the distal quadriceps tendon complex, popularly known as "jumper's knee". They review the diagnostic aspects and discuss the treatment. In particular, they suggest a surgical approach that is not limited to the inflammatory or degenerative component of the syndrome, but also aims to correct imbalance of the extensor apparatus
β-blockade treatment in heart failure: The cardiac insufficiency bisoprolol study (CIBIS) project
No full textThe emerging role of cardiovascular risk factor-induced mitochondrial dysfunction in atherogenesis
No full textAbstract An important role in atherogenesis is played by oxidative stress, which may be induced by common risk factors. Mitochondria are both sources and targets of reactive oxygen species, and there is growing evidence that mitochondrial dysfunction may be a relevant intermediate mechanism by which cardiovascular risk factors lead to the formation of vascular lesions. Mitochondrial DNA is probably the most sensitive cellular target of reactive oxygen species. Damage to mitochondrial DNA correlates with the extent of atherosclerosis. Several cardiovascular risk factors are demonstrated causes of mitochondrial damage. Oxidized low density lipoprotein and hyperglycemia may induce the production of reactive oxygen species in mitochondria of macrophages and endothelial cells. Conversely, reactive oxygen species may favor the development of type 2 diabetes mellitus, mainly through the induction of insulin resistance. Similarly - in addition to being a cause of endothelial dysfunction, reactive oxygen species and subsequent mitochondrial dysfunction - hypertension may develop in the presence of mitochondrial DNA mutations. Finally, other risk factors, such as aging, hyperhomocysteinemia and cigarette smoking, are also associated with mitochondrial damage and an increased production of free radicals. So far clinical studies have been unable to demonstrate that antioxidants have any effect on human atherogenesis. Mitochondrial targeted antioxidants might provide more significant results.</p
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