Daily Variations in the Responses to Papaverine but not Theophylline in Rat Aorta

The presence of temporal patterns in the responses of vascular smooth muscle to relaxing agents have been known. The aim of this study was to examine the variations in the in vitro sensitivity of rat aorta to papaverine and theophylline in both endothelium-intact and -denuded rings. The animals were synchronized with a 12-h light: 12-h dark schedule. Rat thoracic aorta rings were obtained from animals sacrificed at six different times (09:00, 13:00, 17:00, 21:00, 01:00 and 05:00) of the day. Tissues were precontracted submaximally with phenylephrine and then were relaxed by papaverine (10^?8 ? 10^?4 M) and theophylline (10^?7 ? 10^?3 M) applied cumulatively. The responses to most of the concentrations and EC₅₀ values for papaverine demonstrated an ultradian rhythm with an 8 h periodicity. Time-dependent variations were not found in the responses to theophylline. The results are discussed in relation with the time-dependent differences in signal transducing mechanisms.     

Volatile organic compound concentrations and their health risks in various workplace microenvironments

Abstract

Volatile organic compounds (VOCs) are some of the most important pollutants that have adverse effects on human health. In this study, simultaneous indoor and outdoor air samples were collected from four types of microenvironments (restaurants, photocopy centers, dry cleaners, and auto paint shops) in Kocaeli, Turkey in both winter and summer. Twenty-four VOCs were detected using gas chromatography and a flame ionization detector. The aim of the study was to determine the VOC concentrations in various workplaces and investigate associated health risks. Results show that the highest mean total VOC concentrations are in auto paint shops (14,066 µg/m³ in winter, 3441 µg/m³ in summer) followed by dry cleaners, restaurants, and photocopy centers. Total cancer risk was approximately 310 times greater than the acceptable limit in auto paint shops, 44 times greater in restaurants, 42 times greater in dry cleaners, and 17 times greater in photocopy centers. Total hazard quotients were also greater than the acceptable limit in all microenvironments.     

A study of the olfactory sensitivity of crucian carp (Carassius carassius) and goldfish (Carassius auratus) to 17{alpha}, 20{beta}-dihydroxy-4-pregnen-3-one and prostaglandin F2{alpha}

In the male goldfish (Carassius auratus), the hormones 17     

A Case of Budd-Chiari Syndrome Associated with Alveolar Echinococcosis

Although alveolar echinococcosis (AE) can cause a serious disease with high mortality and morbidity similar to malign neoplasms. A 62-year-old woman admitted to a hospital located in Sivas, Turkey, with the complaints of fatigue and right upper abdominal pain. On contrast abdominal CT, a 54×70×45 mm sized cystic lesion was detected in the left lobe of the liver that was seen to extend to the posterior mediastinum and invade the diaphragm, esophagus, and pericardium. The cystic lesion was seen to be occluding the inferior vena cava and left hepatic vein at the level where the hepatic veins poured into the inferior vena cava. Bilateral pleural effusion was also detected. We discussed this secondary Budd-Chiari Syndrome (BCS) case, resulting from the AE occlusion of the left hepatic vein and inferior vena cava, in light of the information in literature.     

Investigation of the possible protective role of gallic acid on paraoxanase and arylesterase activities in livers of rats with acute alcohol intoxication

Gallic acid, a polyphenyl class natural product from gallnut and green tea, is known to be antioxidant, anti‐inflammatory and radical scavenger. In this study, we aimed to investigate the possible protective effects of gallic acid on paraoxonase and arylesterase activities in liver exposed to acute alcohol intoxication. Paraoxonase and arylesterase activities in liver tissue and serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were measured. Histological investigations were also made. In our study, we observed a significant increase of serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities, which are indicators of liver damage after acute ethanol consumption. Gallic acid therapy has significantly reduced the increase in these biomarkers, indicating a possible hepatoprotective effect of gallic acid. Ethanol consumption caused a significant decrease in liver paraoxonase activity (P < 0.001). Gallic acid treatment partly restored this decreased paraoxonase activity, which resulted from ethanol administration. A gallic acid dose of 100 mg/kg was observed as highest restoring effect for paraoxonase activity (P < 0.05). The activity of arylesterase was decreased in the ethanol group as compared with the control group, but this was not significant. However, 50 mg/kg of gallic acid treatment restored the loss of this activity due to ethanol exposure (P < 0.001). We observed that gallic acid ameliorates the liver damage caused by excessive alcohol consumption in a dose‐dependent way. Our results in this study showed that gallic acid might have a protective effect against alcoholic liver disease. Copyright © 2012 John Wiley & Sons, Ltd.     

Planning a lab lesson on the law of thermal conduction with learning by preparing to teach design

Lab activities have been innovated and progressed to fulfill the purpose that students need to experience physics concepts through hands-on and minds-on interactions. However, student-centered and conceptual activities in physics labs are challenged with time and material constraints that degrades the merits of the learning environment. This study adopts a pedagogical design, “learning by preparing to teach”, to address the challenges with conducting a satisfactory number of activities in physics labs and therefore promoting student hands-on and minds-on experiences with the activities. Eight activities covering the conceptual variables of thermal conduction in a two-hour lab session were studied by freshmen students at a university. To implement the pedagogical design, the students were arranged into the learning and teaching groups that paved way to a lab design that student was first learners and then teachers. Lab activities were configured that each group studied a certain set of activities. Upon completing the activities, members of the learning groups were designated to the teaching groups in which students cooperated to achieve conceptual objectives of the lab. The results showed that a usual lab duration becomes effective to cover numerous activities.     

The Role of Oxidative Stress,Renal Inflammation,and Apoptosis in Post Ischemic Reperfusion Injury of Kidney Tissue: the Protective Effect of Dose-Dependent Boric Acid Administration

Biological Trace Element Research - Ischemia/reperfusion (I/R) injury is associated with a strong inflammatory and oxidative stress response to hypoxia and reperfusion that impair organ function....     

Effect of Time on Endothelium-Dependent Relaxations in Mice and Rat Thoracic Aortas

Temporal variations in the endothelium-dependent relaxant effects of acetylcholine (ACh) in mice and histamine (HA) in rat thoracic aorta have been studied. The relaxations induced by higher concentrations of ACh and HA were significantly dependent on the time the tissues were obtained. However, neither EC 50 (the concentration inducing half of the maximum response) values for ACh and HA, nor K B (antagonist dissociation constant) values for atropine and diphenhydramine were found to be statistically significant depending upon the time of obtaining aorta preparations. These results show that the in vitro responsiveness of mice and rat thoracic aortas to endothelium-dependent relaxant effects of ACh and HA, respectively, changes over a 24-h period. These variations might be dependent on a temporal rhythm in post-receptor events, i.e., guanylate cyclase-cGMP-phosphodiesterase system which mediates responses to endothelium-derived relaxing factor(s).