Effects of water hardness and temperature on the acute toxicity of mercuric chloride on rainbow trout (Oncorhynchus mykiss)

In this study, the toxicity of mercuric chloride (HgCl(2)), an important pollutant threatening water resources for many years, and the effects of water temperature and hardness on the toxicity in cultured rainbow trout Oncorhynchus mykiss (4.79 ± 0.16 g; 7.38 ± 0.24 cm; mean ± SD) were investigated at different temperatures (12 and 17°C) and hardness concentrations (35, 70 and 120 mg l(-1) as calcium carbonate, CaCO(3)). For this purpose, the acute toxicity tests were performed by 96-h static tests in different water temperatures and water hardness concentrations. For acute toxicity tests, solutions ranging from 0.4 to 1.2 mg l(-1) were used at 12°C and solutions ranging from 0.4 to 1.0 mg l(-1) at 17°C. The LC(50) values of HgCl(2) that killed 50% of rainbow trout within 96 h in the hardness concentrations of 35, 70 and 120 mg l(-1) CaCO(3) were calculated using probit analysis, and were found to be 0.725, 0.788, 0.855 mg l(-1) at 12°C and 0.670, 0.741, 0.787 mg l(-1) at 17°C, respectively. Consequently, the toxicity of HgCl(2) on rainbow trout decreased when the temperature decreased from 17 to 12°C. Toxicity increased when the hardness decreased from 120 to 35 mg l(-1) CaCO(3). In contrast to temperature, water hardness presents a negative effect on the toxicity of HgCl(2).     

Influence of enantiomers of 1-naphthylalanine in position 2 of VAVP and dVAVP on their pharmacological properties

In this study, we described the synthesis and some pharmacological properties of four new analogues of arginine vasopressin (AVP). Two peptides are substituted in position 2 with L-1-naphthylalanine (L-1-Nal) or its D-enantiomer and in position 4 with valine. In the further two compounds, we combined the above modifications with placement into position 1 of 3-mercaptopropionic acid residue (Mpa). All new peptides were tested for vasopressor and antidiuretic activities. We also estimated the uterotonic activities of these compounds in vitro. Urine samples prior and after peptide administration were analyzed for electrolytes excretion. All analogues are potent oxytocin antagonists. One of them, namely [L-1-Nal2,Val4]AVP, which appears practically not to interact with V1a and V2 receptors, is exceptionally selective. Our results open new possibilities for the design of very potent and selective oxytocin antagonists in vitro.     

Successful retrieval of a broken intravascular ultrasound catheter tip from a coronary artery

The fracture of IVUS catheter tip in the coronary artery is a very rare complication. It should be removed as soon as possible. Although it seems to be easy at first glance, percutaneous retrieval of broken IVUS catheter tip has some challenges. We hereby present a case report of successful percutaneous retrieval of broken IVUS catheter, probably caused by calcific left main stenosis, from the left circumflex artery using loop snare technique.     

Clinical Electrophysiologic Assessment of Ulnar Nerve Transposition in Tuberculoid Leprosy

Ulnar nerve transposition was accomplished in 24 tuberculoid leprotic patients, making a total of 27 operations. Results were assessed clinically and electrophysiologically, pre- and postoperatively. and compared with a control group of 30 patients. Excellent results were obtained in early cases with minimal electromyographic changes. Late cases did not improve after surgery.     

Association of retinal biomarkers and choroidal vascularity index on optical coherence tomography using binarization method in retinitis pigmentosa

Graefe's Archive for Clinical and Experimental Ophthalmology - To investigate the association of retinal biomarkers with the choroidal parameters in retinitis pigmentosa (RP). This prospective...