Protective effect of selenium treatment on diabetes-induced myocardial structural alterations

One of the main causes leading to mortality in diabetes is myocardial disease. Using streptozotocin (STZ)-induced diabetic animals, it has been possible to characterize diabetes-induced myocardial abnormalities. Interstitial and microvascular disorders are known to be a characteristic part of the diabetic cardiomyopathy and partly resist insulin therapy. Because diabetic damage is partly attributed to oxidative stress, antioxidant treatment may be able to reduce this damage. The aim of this study was to investigate the cardioprotective effect of sodium selenite, known as an antioxidant agent. The diabetes was induced by ip injection of 50 mg/kg body wt STZ. The duration of diabetes was 5 wk. The protected group received (ip) 5 μmol/kg body wt/d sodium selenite (Na₂SeO₃) over 4 wk following diabetes induction. Electron and light microscopic morphometry of heart samples revealed typical diabetic alterations consisting in an increase in collagen content, vacuolation, diminishing of the cardiomyocyte diameter, alteration in myofilaments and Z-lines of myofibers, and myofibrillary degeneration. Sodium selenite treatment could prevent the loss of myofibrills and reduction of myocyte diameter. In the sodium-selenite-treated diabetic rat heart, alterations of the discus intercalaris and nucleus were corrected, and degenerations seen in myofilaments and Z-lines were reversed by this treatment. Under these findings, one can suggest that sodium selenite treatment may alleviate late diabetic complications when it is used under control conditions.     

Erythrocyte antioxidant activity and trace element levels in Behçet’s disease

Selenium (Se), zinc (Zn), copper (Cu), and antioxidant enzyme (superoxide dismutase [SOD] and glutathione peroxidase [GSH-Px]) levels in sera were detected in Behçet patients. Age and sex matched controls were used to find out if oxidative stress takes place in the etiopathogenesis of Behçet’s disease. Superoxide dismutase levels were found to be lower in the whole patients group when compared to controls. In whole patients and inactive patients’ group Zn and Se levels were found to be higher, but not different in the active patients group when compared to controls. No significant difference was found between the groups as Cu and glutathione peroxidase levels were taken into consideration. According to the results of the present study, SOD level is low in Behçet’s disease patients’ sera independent from the phase of the disease, and as a result of decreased SOD activity, increased production of free oxygen radicals may play a role in the etiopathogenesis of the disease.     

A new species of Petroleuciscus (Teleostei: Cyprinidae) from the Büyük Menderes River,southwestern Anatolia,Turkey

Petroleuciscus ninae sp. nov. is described from the Büyük Menderes River drainage. The new species is distinguished by having a black lateral stripe from head to base of caudal fin, stripe distinct anteriorly and posteriorly, wider than eye diameter; numerous black pigments on anal‐fin rays; body depth at dorsal‐fin origin 27–30% standard length (L_S); head width at posterior margin of eye 16–19% L_S; and eye diameter smaller than snout length. Petroleuciscus ninae is also distinguished from other species in adjacent waters by having six fixed diagnostic nucleotide substitutions in the mitochondrial DNA coI barcode region.     

Serum copper and zinc levels and copper/zinc ratio in patients with breast cancer

Serum copper, zinc levels, and the Cu/Zn ratio were evaluated in 31 patients with breast cancer and 35 healthy controls. Copper and zinc were determined by atomic absorbtion spectrophotometry. The mean serum copper level and the mean Cu/Zn ratio in patients with breast cancer were significantly higher than the control group (p<0.001 andp<0.001). In addition, the mean serum zinc level in patients with breast cancer was significantly lower than the control group (p<0.001). Neither serum copper and zinc levels nor the Cu/Zn ratio were of value in discriminating of the disease activity and severity. Interestingly, the Cu/Zn ratio in premenopausal patients was higher than postmenopausal patients (p<0.05) and this was not related to age. The further combined biological and epidemiological studies are necessary to investigate the roles of copper and zinc in breast cancer.     

“Constructing” the Cell Cycle in 3D

The cycle of duplication and division, known as the cell cycle, is the essential mechanism by which all living organisms reproduce. This activity allows students to develop an understanding of the main events that occur during the typical eukaryotic cell cycle mostly in the process of mitotic phase that divides the duplicated genetic material creating two genetically identical daughter cells.     

Selenium alters the lipid content and protein profile of rat heart: an FTIR microspectroscopic study

Cardiovascular disease is one of the most important causes of morbidity and mortality in Western countries. In addition, it is well documented that selenium (Se) deficiency has been linked to cardiovascular diseases. This study was undertaken to present the effect of sodium selenite on left and right myocardia, and small veins of normal control rat heart at molecular level by using Fourier transform infrared (FTIR) microspectroscopy. The results mainly reveal that, Se treatment causes an increase in lipid content both in the saturated and unsaturated lipids, and an alteration in protein profile with a decrease in alpha-helix and an increase in beta-sheet structure of the rat heart which might be reflecting a slight subtoxic effect of selenium supplementation on normal rat heart at the dose used in this study.     

Education for expectant fathers in workplaces in Turkey

Worldwide, there is increasing recognition that if family and reproductive health programmes are to be successful, the involvement of men is essential. As part of the problem, men also have to be seen as part of the solution. The reality is that in many countries, including Turkey, men generally do not accompany their partners to health facilities for family planning, antenatal and postnatal services and are not expected to attend the labour or birth of their child. Workplace programmes are a potential strategy for meeting the reproductive health education needs of men in industrial cities such as Istanbul. This intervention study was developed to test the feasibility and effects of expanding a special programme for expectant fathers to large workplaces in Istanbul, with the aim of improving the health of Turkish families during the pregnancy, birth and newborn periods. The findings indicate that it is possible to train workplace physicians in Istanbul to conduct regular educational programmes for expectant fathers on reproductive health, and that such programmes may have beneficial effects, especially in the areas of pregnancy nutrition, exclusive breast-feeding, and support behaviours. Considering the difficulty of getting men to attend hospital or clinic-based educational programmes in large urban areas, bringing such training programmes to men at their places of work has the potential to be an important strategy. Given that large workplaces in Turkey already have full-time physicians charged with the duty of health education for employees, this is also a feasible strategy.     

Sex-related effects on diabetes-induced alterations in calcium release in the rat heart

The present study was designed to determine whether the properties of local Ca(2+) release and its related regulatory mechanisms might provide insight into the role of sex differences in heart functions of control and streptozotocin-induced diabetic adult rats. Left ventricular developed pressure, the rates of pressure development and decay (+/-dP/dt), basal intracellular Ca(2+) level ([Ca(2+)](i)), and spatiotemporal parameters of [Ca(2+)](i) transients were found to be similar in male and female control rats. However, spatiotemporal parameters of Ca(2+) sparks in cardiomyocytes isolated from control females were significantly larger and slower than those in control males. Diabetes reduced left ventricular developed pressure to a lower extent in females than in males, and the diabetes-induced depressions in both +dP/dt and -dP/dt were less in females than in males. Diabetes elicited a smaller reduction in the amplitude of [Ca(2+)](i) transients in females than in males, a smaller reduction in sarcoplasmic reticulum-Ca(2+) load, and less increase in basal [Ca(2+)](i). Similarly, the elementary Ca(2+) events and their control proteins were clearly different in both sexes, and these differences were more marked in diabetes. Diabetes-induced depression of the Ca(2+) spark amplitude was significantly less in females than in matched males. Levels of cardiac ryanodine receptors (RyR2) and FK506-binding protein 12.6 in control females were significantly higher than those shown in control males. Diabetes induced less RyR2 phosphorylation and FK506-binding protein 12.6 unbinding in females. Moreover, total and free sulfhydryl groups were significantly less reduced, and PKC levels were less increased, in diabetic females than in diabetic males. The present data related to local Ca(2+) release and its related proteins describe some of the mechanisms that may underlie sex-related differences accounting for females to have less frequent development of cardiac diseases.     

The role of gender differences in beta-adrenergic receptor responsiveness of diabetic rat heart

Since the mechanisms responsible for gender differences in cardiac contractile function have not been fully elucidated, we focused to determine the effect of gender difference on β-adrenergic receptors (β-ARs) signal transduction in ventricular cardiomyocytes from insulin-dependent diabetic (streptozotocin-induced) rats. Dose-response curves of left ventricular developed pressure (LVDP) to isoproterenol (ISO) in females showed that there was only a ∼30% decrease in the maximum response without a significant shift in EC₅₀ in diabetic females. On the other hand, diabetes induced a clear rightward shift in the potency (5–10 folds) without a significant change in the maximum response in the males. In order to further determine of the underlying mechanism for this difference, we measured cAMP production and obtained dose-response curves with ISO stimulation in isolated cardiomyocytes. In diabetic females, there was no obvious change in the cAMP dose-response curve. On the other hand, there was a significant decrease in the maximum response without any apparent change in the potency of diabetic males. Our findings indicate that male and female rats are affected differently by diabetes in terms of LVDP responses to β-ARs stimulation. Also, the difference between their β-ARs induced cAMP responses may underlie this disparity.