Hildebrando Gomes Benedicto

Structural arrangement of the cardiac collagen fibers of healthy and diabetic dogs

The heart is composed by a specialized muscle, whose form and function are essentials for an adequate work and shows an amount of connective tissue which support and provide insertion for this muscle, whose collagen fibers are responsible for determination of tissue feature. Our objective was to identify the structural arrangement of the heart collagen fibers in dogs. The hearts of the dogs were submitted to the process of the controlled digestion with NaOH solution and observed by scanning electron microscope. Our results showed that the collagen fibers of the endomysial wall have structural arrangement composed by an irregular network with one layer in normal dogs but in diabetic dogs the network acquires a greater amount of the fibers and layers, looking like a “rug” of fibers modifying the relationships of the stress/strain of the tissue. Ahead of the observed results we are able to conclude that exist increase in the amount and thickness of cardiac collagen fibers, beyond the increase of layers and architectural disarrangement in the endomysial wall in the diabetic dogs. Microsc. Res. Tech. , 2011.

Análise comparativa entre a vascularização ventricular e do nó sinoatrial em gatos

The possible existence of interdependence in the blood nutrition of both atrial and ventricular territories has been a subject of concern to cardiologists, mainly related to vascularization of the sinoatrial node and its dependence on just one coronary artery or both, and its relation with the predominance of these vessels in the ventricular vascularization. Therefore, this research aimed evaluated the relation of blood irrigation of the sinoatrial node in relation to the coronary artery predominance in the ventricle vascularization. In doing so, we analyzed 30 hearts of cats without pedigree, males and females, adults of several ages. They were not carrying any heart problems. The hearts were injected by the thoracic aorta with Neoprene Latex 450, stained with red pigment, and then they were dissected. It was found that when there was a prevalence of ventricular vascularization of the left type (63.34%) the sinoatrial node irrigation was predominantly in the dependency of the Ramus proximalis atrii dextri (78.9%) or with less frequency by Ramus proximalis atrii sinister (21.1%). In the ventricular vascularization of the balanced type (33.34%), the pacemaker irrigation was in dependence more often of Ramus proximalis atrii dextri (80%) or with less frequency the nutrition of the sinoatrial node occurred by Ramus proximalis atril sinister (20%). In a single-case, we observed the ventricular vascularization of the right type (3.34%), the pacemaker nutrition was in an exclusive dependence of the Ramus intermedius atril dextri. These results suggest in this species there is no relationship between both the sinoatrial node irrigation and the type of ventricular vascularization, regardless of gender.

Morfometria das fibras colágeno cardíaco em ratos sadios e diabéticos suplementados com vitamina C

The increase of heart collagen fibers in diabetics is a well known fact, but the consequences are not defined. The aim was to quantify the cardiac collagen fibers in normal and diabetic rats treated with vitamin C. We selected 32 Wistar rats, 16 diabetic animals induced endovenously with streptozootocin, and 16 healthy animals, half of them, diabetics and normals, were treated with vitamin C for 90 days. After the experimental proceeding, the hearts were removed and processed accordingly to conventional protocol for optical microscopy and specific staining for collagen. The results showed that the diabetic rats presented increase in the number of cardiac collagen fibers, but the ones treated with vitamin C showed little accumulation of fibers. It could be concluded that treatment with vitamin C is important for the prevention of heart failure in diabetic animals.

Can the indicators of chronic ethanol consumption be minimized by a continuous flaxseed intake

The aim of this study was to evaluate the use of flaxseed in animals subjected to ethanol‐induced hepatotoxicity. Twenty‐four male rats were divided into four groups (n = 6): control group (CG) which received a control diet and water ad libitum; flaxseed group (FG) which received control diet with an addition of 25% flaxseed flour and water ad libitum; ethanol control group (ECG) which received control diet and a solution of 10% ethanol (v/v) as the only liquid source; and ethanol flaxseed group (EFG) which received control diet with an addition of 25% flaxseed flour and a solution of 10% ethanol (v/v) as the only liquid source. The animals were euthanized at 60 days, when blood was collected for biochemical analysis and liver was collected for histomorphometric analysis. Rats fed with diets containing flaxseed showed lower values of alkaline phosphatase (P = 0.020) and lower concentration of total bilirubin (P = 0.006), direct bilirubin (P = 0.013) and indirect bilirubin (P = 0.018) compared to ECG and EFG. The groups receiving flaxseed diets demonstrated higher expression of superoxide dismutase (SOD) enzyme (P < 0.001) than CG and ECG but did not affect thiobarbituric acid (TBARS) expression (P = 0.055). Regarding liver analysis, the ECG and EFG showed larger hepatocyte nuclei and paler cytoplasm than the groups who had not received ethanol, and less in fluid accumulation (oedema) in the cytoplasm than was seen in the FG and EFG livers. These latter two groups showed fewer fatty cells than was seen in the groups that had not been given flaxseed, so that the diagnosis of hepatic steatosis was not justified. In conclusion, therefore, this study showed that the indicators of ethanol chronic consumption can be reduced by the introduction of continuous flaxseed dietary intake.

Quantificação de tecido conjuntivo do músculo cardíaco em equinos de tração através de técnicas histoquímicas e morfométricas

ABSTRACT Cardiomyocytes are sustained and inserted into aconnective tissue skeleton that has different distributiondepending up on the properties of the region in which it stands.The purpose of this study was to quantify the proportion ofconnective tissue in relation to the arrangement ofcardiomyocytes of left and right ventricles and interventricularseptum in myocardium of six mixed breed, ill trifted adulthorses, of both sexes, used for traction. With hearts still freshand with the aid of a digital caliper, it was estimated the heightof left ventricle, the heart’s width, the heart’s circumferenceand the thickness of the ventricular free walls and interventricularseptum. The fragments on the middle third of the interventricularseptum and free walls of the ventricles were subjected toconventional histological technique. The blocks were cut withthickness of 5 μ m and stained with Picrosirius Red, GomoriTrichrome and Azan Trichrome to show the connectivetissue. The slides were analyzed using optical microscopecoupled to a digital analysis program Image-Pro Plus®. Theaverage proportion of connective tissue in the left ventricle was6.1+3.7%, in the interventricular septum and it was observed amean of 6.8+3.6%. In the right ventricle the average was6.0+3.0%. Applying the H test of Kruskal-Wallis, it was foundthat there was statistical difference between the different dyesused for each region. In the Pearson correlation test it was notfound pattern correlation between the thickness of the regionsanalyzed and the proportion of connective tissue