Short-Term swimming therapy is not benefical in an experimental animal model of myorcadial infarctation

Myocardial infarction is a major cause of mortality worldwide. Physical exercise appears to reduce complicationsassociated with myocardial infarction by contributing to cardiac remodeling. The aim of this study was toinvestigate the relation between cardiac remodeling and short-term physical activity. We segregated 9 maleWistar rats into 3 groups: non-operated control, sham-operated (subjected to open chest surgery), and operated(subjected to open chest surgery and ligation of the left anterior descending coronary artery). Operatedand sham-operated animals were enrolled in a physical activity program shortly after surgical recovery. Nonoperatedcontrol rats did not receive physical activity stimulation. The heart size and heart wet weight/body weight ratio in operated rats significantly increased compared with that in control or sham-operatedrats. Moreover, operated rats showed histological evidence of myocardial cell swelling and disorganizationof myocyte architecture. These changes were not observed in control or sham-operated rats. Performingshort-term physical activity at the acute phase of myocardial injury does not mitigate the effects of myocardialinfarction, as evidenced by increased heart size and altered histological features. Longer training sessionsmight be required for obtaining any benefit.

A study on maturation of thyroid gland in human fetuses

The thyroid gland is the first endocrine gland to appear on the embryonic period. Its organogenesis beginswhen the medium endoderm cells start getting thick, forming a diverticulum, in the primitive pharynx floor.In this report, we describe the histological maturation of thyroid gland in human fetuses, correlating the tissueaspects with pregnancy stage. Twenty human fetuses were used in this study in different developmental stages.The fetuses from 20 to 36 weeks (gestational age) were dissected and the thyroid gland removed. The glandwas then embedded in paraffin, cut in frontal plans portions and stained with Hematoxylin and Eosin (H&E).We observed that the maturation process of the thyroid follicles was directly correlated with the gestationalage, where human fetus with 23 weeks of age did not show any sign of follicles or colloid and the one with35 weeks of age presented follicles with colloid. The conclusion of this study was that maturation process ofthe thyroid follicles tissue is a linear process with the fetal development.