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Biomedical subjects

J Coucelo

Publications and source records attributed to J Coucelo.

At least 19 recordsLinked to original sources
PubMed2006

Vanadium distribution, lipid peroxidation and oxidative stress markers upon decavanadate in vivo administration.

The contribution of decameric vanadate species to vanadate toxic effects in cardiac muscle was studied following an intravenous administration of a decavanadate solution (1mM total vanadium) in Sparus aurata. Although decameric vanadate is unstable in the assay medium, it decomposes with a half-life time of 16 allowing studying its effects not only in vitro but also in vivo. After 1, 6 and 12h upon decavanadate administration the increase of vanadium in blood plasma, red blood cells and in cardiac mitochondria and cytosol is not affected in comparison to the administration of a metavanadate solution containing labile oxovanadates. Cardiac tissue lipid peroxidation increases up to 20%, 1, 6 and 12h after metavanadate administration, whilst for decavanadate no effects were observed except 1h after treatment (+20%). Metavanadate administration clearly differs from decavanadate by enhancing, 12h after exposure, mitochondrial superoxide dismutase (SOD) activity (+115%) and not affecting catalase (CAT) activity whereas decavanadate increases SOD activity by 20% and decreases (-55%) mitochondrial CAT activity. At early times of exposure, 1 and 6h, the only effect observed upon decavanadate administration was the increase by 20% of SOD activity. In conclusion, decavanadate has a different response pattern of lipid peroxidation and oxidative stress markers, in spite of the same vanadium distribution in cardiac cells observed after decavanadate and metavanadate administration. It is suggested that once formed decameric vanadate species has a different reactivity than vanadate, thus, pointing out that the differential contribution of vanadium oligomers should be taken into account to rationalize in vivo vanadate toxicity.

Animals↗
PubMed2003

Acute effects of vanadate oligomers on heart, kidney, and liver histology in the Lusitanian toadfish (Halobatrachus didactylus).

The contribution of vanadate oligomers to the acute histological effects of vanadium was analyzed in the heart, kidney, and liver of Halobatrachus didactylus (Schneider, 1801). A sublethal vanadium dose (5 mM, 1 mL/kg) in the form of metavanadate (containing ortho and metameric species) or in the form of decavanadate (containing only decameric species) was intraperitoneally administered by injection, and specimens of H. didactylus were sacrificed at one and seven days postinjection. Sections of heart ventricle and renal and hepatic tissue were stained with hematoxylin-eosin and examined by light microscopy to identify vanadium-induced tissue injury. In addition, PicroSirius-stained ventricular sections were analyzed by bipolarized light microscopy to determine the fraction of myocardium occupied by the ventricular wall structural elements (collagen I, collagen III, and cardiac muscle). Both vanadate solutions produced similar effects in the renal tissue. Morphological alterations included damaged renal tubules showing disorganized epithelial cells in different states of necrosis. Reabsorbed renal tubules and hyperchromatic interstitial tissue were also observed. The hepatic tissue presented hyperchromatic and hypertrophied nuclei, along with necrotic and hypertrophied hepatocytes, and more severe changes were observed in the liver with exposure to decavanadate. Vanadate oligomers promoted evident tissue lesions in the kidney and liver, but not in the cardiac tissue. However, cardiac tissue structural changes were produced. For example, decavanadate induced a hypertrophy of the ventricle due to a decrease in the percentage of myocardium occupied by collagen fibers. In general, decavanadate was shown to be more toxic than metavanadate.

Animals↗
PubMed2000

Calculation of volumes and systolic indices of heart ventricle from Halobatrachus didactylus: echocardiographic noninvasive method.

The purpose of this work is to calculate end-systolic and end-diastolic volumes of Halobatrachus didactylus ventricles, from two-dimensional (2D) echocardiographic images, comparing four different linear methods, and to derive systolic indices of ventricular function-fractional shortening, ejection fraction, stroke volume, and cardiac output independent of the Fick principle. Echocardiography provided high resolution images of cardiac structures and allowed accurate linear measurements. The Simpson algorithm proved to be the best method of calculating ventricle volumes. As a corollary, ventricular mass can be derived from echocardiographic volume data. This noninvasive method promises wide utilization in experimental comparative cardiovascular biology.

Algorithms↗
PubMed2000

Myocardial architecture, texture and left ventricular heterogeneity in the pulsed Doppler tissue imaging pattern.

The regional contribution for the global ventricular functional performance is complex and heterogeneous, the myocardial texture could reflect this particular aspect, during the phases of myocardial contraction and relaxation. The objective of our clinical study was to evaluate the relationship between the segmental myocardial velocity pattern by Doppler tissue imaging and the ultrasound characteristics of the left ventricular myocardium analysed by computerized ultrasound densitometry with the calculation of its intensity (dB), in a population of 22 subjects without clinical history of cardiovascular pathology, 50% female gender, mean age 43 +/- 11 years (19-66 years). In the methodology of study, the left ventricular myocardium was divided in 16 segments, according with the transthoracic echocardiographic recommendations of the American Society of Echocardiography (A.S.E.). During one cardiac cycle interval, the ultrasound characteristics of the left ventricular myocardium were evaluated continuously and in a quantitative manner, applying the computerized ultrasound densitometry method on the gray scale images of the ventricular myocardium, with the sample size identical to the myocardial wall thickness. The peak (Vmax-cm/sec) and mean (Vm-cm/sec) pulsed Doppler tissue imaging velocities, individuals, segmental and a total velocities, contraction and relaxation velocities of the left ventricular myocardium were obtained immediately after the computerized ultrasound densitometry analysis. Ultrasound densitometry and Doppler tissue imaging data were obtained in a total number of 352 left ventricular myocardial segments. Using the multiple linear correlation matrix analysis, the ultrasound intensity registered inverse significant correlation's with the Doppler tissue imaging Vmax and Vm for the systolic "s" wave in the total segments and each one of them (r = -0.66; p = 0.001; interval 2-18 cm/sec; r = -0.52 to -0.70) and with the early diastolic "e" wave (r = -0.42; p = 0.01; interval 2-19 cm/sec; r = -0.35 to -0.55). Direct correlation's were obtained for the computerized ultrasound densitometry intensity and Doppler tissue imaging Vmax and Vm of the late diastolic "a" wave in the total number of the left ventricular myocardial wall segments and in each one of them (r = 0.51; p = 0.01; interval 1-17 cm/sec; r = 0.42 a 0.66). We conclude that in our study and under physiological conditions of myocardial performance, a direct correlation was obtained between the ultrasound characteristics of the ventricular myocardial imaging and its velocities of contraction and relaxation. These facts reflect the close relationship between left ventricular myocardial structure and function, analyzed by the new ultrasound Doppler technologies.

Adult↗
PubMed2000

Importance of lipoprotein metabolism parameters in the clinical and angiographic severity of coronary artery disease.

Coronary artery disease that is clinically and angiographically significant is associated to important biochemical parameters with direct interference in lipoprotein and apoprotein metabolism. The purpose of our study was to evaluate the importance of several lipoprotein metabolic parameters in the clinical and angiographic severity of chronic coronary artery disease. In a population with the diagnosis of ischemic coronary artery disease, we assessed the degree of angiographic (single- versus multivessel disease) and clinical (C.C.S. I-IV classification) severities. In each patient, we determined the value of total cholesterol, triglycerides, HDL and LDL cholesterol, HDL 2 and 3, apoprotein AI and B, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. Our results showed that some parameters were significant in the comparison between a normal group and the global coronary artery disease population, such as the value of total cholesterol, HDL cholesterol, HDL 2, apoprotein AI and B lipoprotein (a) and anti-phospholipid antibodies. In the distinction of coronary artery disease subgroups, in relation to C.C.S. < or = 2 and > or = 3 classes, some factors could be discriminated, such as HDL cholesterol, HDL 2, total cholesterol/HDL, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. In the distinction between classes C.C.S. < or = 2 and AMI, the levels of triglycerides, HDL cholesterol, HDL 2, total cholesterol/HDL, lipoprotein (a) and anti-phospholipid antibodies were significant. In the division between single vessel versus multivessel coronary artery disease we found significant values of HDL cholesterol, HDL 2, total cholesterol/HDL, apoprotein AI, lipoprotein (a), anti-phospholipid antibodies and C reactive protein. In conclusion, our present study endorses the clinical role of lipids and plasma lipoproteins in the determination of several cardiovascular risk factors, but introduction of new parameters such as lipoprotein (a) and the anti-phospholipid antibodies can be very useful for a better and global understanding of the pathophysiological processes and distinction of higher risk subgroups for extension and degree of severity of ischemic coronary artery disease.

Aged↗
PubMed1999

[Primary hyperaldosteronism--12 clinical cases].

STUDY OBJECTIVES: To show clinical, biochemical, and morphological data of 12 patients with primary hyperaldosteronism: eight with an aldosterone-producing adenoma and four with adrenal hyperplasia. To compare clinical and biochemical parameters of the patients with adenoma and hyperplasia. For those with adenoma, to verify clinical and biochemical modifications after adrenalectomy. PATIENTS AND METHODS: In the 12 patients with hyperaldosteronism, retrospective analysis of clinical (age, sex, blood pressure), biochemical (plasmatic and urinary potassium, plasmatic aldosterone, plasma renin activity, and plasmatic aldosterone/renin activity ratio), and morphological (computed tomography, magnetic resonance, and norcholesterol scintigraphy) data was performed. RESULTS: 1--In the 12 patients with hyperaldosteronism (seven female), the age was 51.0 +/- 10.2 years (mean +/- standard deviation), the systolic pressure 200.9 +/- 34.5 mm Hg and the diastolic pressure 120.0 +/- 12.3 mm Hg. Hypertension was diagnosed 12.0 +/- 10.1 years before. As biochemical evidence, we found kalaemia of 3.06 +/- 0.28 and urinary potassium of 63.4 +/- 16.5 mEq/l, renin activity 0.98 +/- 1.02 ng/ml/h, plasmatic aldosterone of 49.4 +/- 36.0 ng/dl, aldosterone/renin activity > 30 in 83% of the cases. As morphological evidence, computed tomography allowed diagnosis in nine patients, suggested it in two, being doubtful in one. Performed on four patients, resonance confirmed the tomography in three and was not contributive in one. The scintigraphy performed in four patients visualized two adenomas, was negative in one adenoma and in one hyperplasia. 2--In the eight patients with adenoma (six female), the youngest age and the highest diastolic pressure compared with patients with hyperplasia were statistically significant (p < 0.01 and 0.05). In the adenomas, the biochemical changes were more pronounced, but not statistically significant. The plasmatic aldosterone/renin activity ratio was also higher in the adenoma cases. 3--After the adrenalectomy, blood pressure became normal in five patients and was more easily therapeutically controlled in three. The average systolic and diastolic pressures decreased and the biochemical parameters became normal in all patients. The pre/post surgical modification of these parameters had statistical significance (systolic pressure decrease, p < 0.01; diastolic pressure decrease, p < 0.01; kalaemia increase, p < 0.001; renin activity increase, p < 0.01; aldosterone decrease, p < 0.02). The plasmatic aldosterone/renine activity ratio normalized in all patients. CONCLUSIONS: In diagnosing primary hyperaldosteronism, biochemical (kalaemia, urinary potassium, plasmatic aldosterone, renin activity, aldosterone plasmatic/renin activity) and tomography studies were important. On comparing the patients with hyperplasia with those with adenoma, we found that the latter are younger and exhibit higher diastolic pressure, both findings with statistical significance. After adenoma surgery, blood pressure became normal in five patients and improved in three, these findings, and the improvement of the kalaemia, plasmatic aldosterone, and renin activity parameters were statistically significant.

Adenoma↗
PubMed1998

[Acute complications of diabetes mellitus].

A retrospective study was made of 83 diabetic patients admitted to the Department of Internal Medicine between January 1986 and December 1993, with acute intercurrence of the disease. The authors considered some clinical features (age, type and frequency of complication, form of presentation, causal aetiology, laboratory findings and therapeutic options). Statistical relationships between different populations were made using the unpaired Student's T. method. Results were compared with those in the literature, leading to some significant conclusions.

Acute Disease↗