Aim: Our study was designed on the hypothesis that homocysteine levels are a prognostic parameter that can predict the severity of COVID-19 disease. Materials & methods: 117 COVID-19 patients and 3...

Transfer operations are one of the stress sources that cause mortality in fish. This study investigated the effects of different dissolved oxygen concentrations on oxidative stress and several biochemical parameters during the transfer of adult rainbow trout (Oncorhynchus mykiss). The aim was to determine the optimum dissolved oxygen concentration to minimize stress and potential tissue damage during transfer. The study analyzed GSH-Px, SOD, and LDH enzyme activities; MDA, Cp, TOS, TAS, OSI, cortisol, glucose, urea, uric acid, creatinine, Ca, Mg, and MDA levels; as well as Cp, TOS, TAS, and OSI values in serum and muscle tissue. Findings indicated that transfer and preparation for transfer induced oxidative damage in fish. Comparing different dissolved oxygen levels, it was observed that hypoxic and hyperoxic conditions increased ROS levels, suppressed the antioxidant mechanism, and caused oxidative stress. Among the tested conditions, transfer under normoxic conditions with a dissolved oxygen concentration of 10 mg/L was the most effective in minimizing oxidative stress and tissue damage. This suggests that maintaining adequate oxygen levels during transfer plays a crucial role in reducing physiological stress in rainbow trout.

In aquaculture, biochemical and hematological analyzes are frequently performed for scientific research, health screening and diagnosis of diseases. Biochemical and hematological parameters in fish as in other vertebrates varies nutrition, water quality, pathogens and various environmental factors that can create stress. Caudal vascular blood collection is a non-invasive method that is widely used to investigate fish health, biochemistry, and physiology. As a result of this method being performed under the influence of a properly selected anesthetic agent, animal welfare is affected the least, thus preventing a serious change in biochemical parameters with minimum stress. In this review, sampling collection suitable for the analysis to be performed and choosing the right anesthetic agent are presented.

In recent years, the increase in obesity in the world has led to the development of new strategies in combating obesity. In the present study, it was aimed to investigate the effect of niacin and melatonin supplements to combat obesity in rats as a model organism. Treadmill exercise was performed on rats after niacin and melatonin supplementation for 10 days. In each group, weight loss was observed at the end of the 10 days exercise. In this study, it was observed that niacin supplementation leading to weight loss in rats that had treadmill exercise when compared to the control group. In addition, it was found that the weight loss observed in melatonin+niacin supplement was higher than niacin supplement only. It was found that the weight loss observed in the group given melatonin+niacin supplement was higher than the weight loss observed in niacin supplement only. As a result, niacin and melatonin supplementation can be recommended before exercise to combat obesity.