In view of the antioxidant properties of melatonin, the effects of melatonin on the oxidative-antioxidative status of tissues affected by diabetes, e.g. liver, heart and kidneys, were investigated in streptozotocin (STZ)-induced diabetic rats in the present study. Concentrations of malondialdehyde (MDA) and reduced glutathione (GSH), and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the tissues were compared in three groups of 10 rats each (control non-diabetic rats (group I), untreated diabetic rats (group II) and diabetic rats treated with melatonin (group III)). In the study groups, diabetes developed 3 days after intraperitoneal (i.p.) administration of a single 60 mg kg(-1) dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mg kg(-1) i.p. dose of melatonin per day. After 6 weeks, the rats in groups II and III had significantly lower body weights and higher blood glucose levels than the rats in group I (p < 0.001 and p < 0.001, respectively). MDA levels in the liver, kidney and heart of group II rats were higher than that of the control group (p < 0.01, p < 0.05, p < 0.01, respectively) and diabetic rats treated with melatonin (p < 0.05). The GSH, GSH-Px and SOD levels increased in diabetic rats. Treatment with melatonin changed them to near control values. Our results confirm that diabetes increases oxidative stress in many organs such as liver, kidney and heart and indicate the role of melatonin in combating the oxidative stress via its free radical-scavenging and antioxidant properties.

No abstract

Background: Chronic obstructive pulmonary disease (COPD) is a consequence of an underlying chronic inflammatory disorder of the airways that is usually progressive and causes dysregulation in the metabolism of collagen. Prolidase has an important role in the recycling of proline for collagen synthesis and cell growth. Objective: We measured and compared prolidase activity in healthy individuals with COPD patients to find out that whether its activity might reflect disturbances of collagen metabolism in the patients. We also investigated oxidative-antioxidative status and its relationship with prolidase activity in this disease. Methods: Thirty voluntary patients with COPD and 30 healthy control subjects with similar age range and sex were included into the study. Plasma prolidase activities, total antioxidant capacity (TAC) and lipid peroxidation (LPO) levels were measured in the patient and control groups.Results: Plasma prolidase activity and TAC levels were significantly lower, and LPO levels were significantly higher in the patients than those in the control subjects (Po0.05, Po0.001, and Po0.001, respectively). Significant correlations were detected between plasma prolidase activity and TAC and LPO levels in the patients group (r 5 0.679, Po0.001; r 5 À426, Po0.05, respectively). Conclusions:The results suggest that oxidative-antioxidative balance and collagen turnover are altered by the development of COPD in human lungs, and prolidase activity may reflect disturbances of collagen metabolism in this pulmonary disease. Monitoring of plasma prolidase activity and oxidativeantioxidative balance may be useful in evaluating fibrotic processes and oxidative damage in the chronic inflammatory lung disease in human.

Stem cell research is a newly emerging technology that promises a wide variety of benefits for humanity. It has, however, also caused much ethical, legal, and theological debate. While some forms of its application were prohibited in the beginning, they have now started to be used in many countries. This fact obliges us to discuss the regulation of stem cell research at national and international level. It is obvious that in order to make regulations and to draw up legislation at national or international levels it helps to know the perspectives of different cultures and faith traditions. In this article the issue is explored from an Islamic perspective. Firstly, some basic information is given about Islam to explain how laws are drawn up and regulations made in this tradition. Secondly, the principles on which the laws and regulations are based are applied to stem cell research, and finally the permitted and prohibited methods of stem cell research are described. The discussions throughout the paper demonstrate that while some ethicists argue that stem cell research is unethical in the Islamic tradition, tradition permits it as long as such research is aimed at improving human health.

Concepts, such as death, life and spirit cannot be known in their quintessential nature, but can be defined in accordance with their effects. In fact, those who think within the mode of pragmatism and Cartesian logic have ignored the metaphysical aspects of these terms. According to Islam, the entity that moves the body is named the soul. And the aliment of the soul is air. Cessation of breathing means leaving of the soul from the body. Those who agree on the diagnosis of brain death may not able to agree unanimously on the rules that lay down such diagnosis. That is to say, there are a heap of suspicions regarding the diagnosis of brain death, and these suspicions are on the increase. In fact, Islamic jurisprudence does not put provisions, decisions on suspicious grounds. By virtue of these facts, it can be asserted that brain death is not absolute death according to Islamic sources; for in the patients diagnosed with brain death the soul still has not abandoned the body. Therefore, these patients suffer in every operation performed on them.