Cardioprotective effect of propranolol on diabetes-induced altered intracellular Ca2+ signaling in rat

We have previously shown that chronic treatment with propranolol had beneficial effects on heart function in rats during increasing-age in a gender-dependent manner. Herein, we hypothesize that propranolol would improve cardiac function in diabetic cardiomyopathy and investigated the benefits of chronic oral administration of propranolol on the parameters of Ca²⁺ signaling in the heart of streptozotocin-diabetic rats. Male diabetic rats received propranolol (25 mg/kg, daily) for 12 weeks, 1 week after diabetes induction. Treatment of the diabetic rats with propranolol did not produce a hypoglycaemic effect whereas it attenuated the increased cell size. Basal and β-agonist response levels of left ventricular developed pressure were significantly higher in propranolol-treated diabetic rats relative to untreated diabetics while left ventricular end diastolic pressure of the treated diabetics was comparable to the controls. Propranolol treatment normalized also the prolongation of the action potential in papillary muscles from the diabetic rat hearts. This treatment attenuated the parameters of Ca²⁺ transients, depressed Ca²⁺ loading of the sarcoplasmic reticulum, and of the basal intracellular Ca²⁺ level of diabetic cardiomyocytes. Furthermore, Western blot data indicated that the diabetes-induced alterations in the cardiac ryanodine receptor Ca²⁺ release channel’s hyperphosphorylation decreased the FKBP12.6 protein level. Also, the high phosphorylated levels of PKA and CaMKII were prevented with propranolol treatment. Chronic treatment with propranolol seems to prevent diabetes-related changes in heart function by controlling intracellular Ca²⁺ signaling and preventing the development of left ventricular remodeling in diabetic cardiomyopathy.     

Preventive and protective effects of Turkish propolis on H₂O₂-induced DNA damage in foreskin fibroblast cell lines

The aim of the present study was to evaluate the potential of Turkish propolis extracts if they prevent or protect foreskin fibroblast cells against hydrogen peroxide (H?O?)-induced oxidative DNA damage. Hydrogen peroxide (40 μM) was used as an inducer of oxidative DNA damage. The damage of DNA was evaluated by using the alkaline single cell gel electrophoresis (comet) assay. Turkish propolis extracts at concentrations of 25, 50, 75 and 100 μg/ml were prepared by ethanol. Anti-genotoxicity was assessed before, simultaneously, and after treatment of propolis extract (50 μg/ml) with H?O?. The results showed a significant decrease in H?O?-induced DNA damage in cultures treated with propolis extract. The antioxidant activity of phenolic components found in propolis may contribute to reduce the DNA damage induced by H?O?. Our findings confirmed the chemopreventive activity of propolis and showed that this effect may occur under different mechanisms.     

Biodegradation of olive-mill pomace mixed with organic fraction of municipal solid waste

This study investigated the effects of organic fraction of municipal solid waste (OFMSW) addition on the anaerobic treatment of the olive-mill pomace. Biodegradability of olive-mill pomace mixed with OFMSW was examined in anaerobic bioreactors. Only OFMSW was loaded in the first (control) bioreactor, while run 1 and run 2 bioreactors included different ratio of OFMSW and olive-mill pomace. COD, BOD₅, NH₄–N, pH, VFA, CH₄ quantity and percentage in anaerobic bioreactors were regularly monitored. In addition, inert COD and anaerobic toxicity assay (ATA) were measured in leachate samples. The results of the study showed that 70% of OFMSW addition to olive-mill pomace has an advantage in terms of pollution parameters and methane generation. Since olive-mill pomace is not easy biodegradable, addition of high proportion of OFMSW promotes biodegradability of olive-mill pomace. Decreasing in BOD₅/COD ratios in the run 1 and run 2 reactors carried out as 62 and 52%, respectively.     

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.     

Gender related differential effects of Omega-3E treatment on diabetes-induced left ventricular dysfunction

The present study was designed to determine whether there are beneficial effects of intake of Ω-3E (containing 70% pure omega-3 and 2% natural vitamin E) in cardiac dysfunction of diabetic rats. We also examined whether there are gender-related differences in the responses to the intake of Ω-3E on the heart dysfunction. Experiments were performed by using Langendorff-perfused hearts from normal, diabetic (with 50 mg/kg streptozotocin), and Ω-3E (50 mg/kg body weight/day) treated diabetic 3-month-old Wistar rats. Ω-3E treatment of the diabetics caused small, but significant decrease (13% and 14% female versus male) in the blood glucose level. Ω-3E treatment of the diabetic female rats did not prevent diabetes-induced decrease in left ventricular developed pressure (LVDP) and increase in left ventricular end-diastolic pressure (LVEDP) with respect to the control female rats. On the other hand, the treatment of diabetic male rats caused significant recovery in depressed LVDP. Furthermore, such treatment of diabetic female and male rats caused significant recovery in depressed rates of changes of developed pressure. This effect was more significant in males. Besides, Ω-3E caused significant further lengthening in the diabetes-induced increased time to the peak of the developed pressure in females, while it normalized the lengthening in the relaxation of the developed pressure in diabetic males. In addition, Ω-3E treatment caused significant restorations in the diabetes-induced altered activities of antioxidant enzymes without any significant gender discrepancy. Present data show that there are gender related differences in diabetic heart dysfunction and the response to antioxidant treatment.     

Clinicopathologic significance of eosinophilic pleural effusions in a population with a high prevalence of tuberculosis and cancer

OBJECTIVE: To reveal the diagnostic and prognostic significance of eosinophilic pleural effusions (EPEs) and assess their clinical implications. STUDY DESIGN: Seventy EPEs from 60 patients among 697 consecutive pleural effusions were investigated from 1996-2005 at Kocaeli University Hospital, Kocaeli, Turkey. Koss and Light's criteria were applied in the analysis, which comprised macroscopic, cytopathologic, biochemical and microbiologic examinations. RESULTS: Overall, cancerous underlying conditions were diagnosed in 22 patients (13 malignant and 9 paramalignant), 36.7% of EPEs. Benign causes were found in 43.3% (26 of 60) of the patients. Twelve pleural effusions (20.0%) were idiopathic. The comparison of pleural fluid and peripheral blood findings disclosed no significant difference among the various subgroups. CONCLUSION: EPE could be associated with inflammatory, benign, cancerous and paramalignant conditions. A closer search for a definite causes is warranted in the setting of EPEs, especially in populations with a high prevalence of tuberculosis and malignancy, such as in Kocaeli, Turkey, an industrial city in a developing country.