Effect of different stress factors on some physiological parameters of Nile tilapia (Oreochromis niloticus)

This study was conducted to determine the effect of different stress factors on some physiological measurements of Nile tilapia (Oreochromis niloticus).A total number of 160 Nile tilapia, the body weight ranging between 100 and 120 g, were exposed to three stress factors of hypoxia, overcrowding and starvation for different periods 24, 72 and 144 h. The results of cortisol level were 134.15, 144.27, 154.12 ng/ml and 140.18 ng/ml for control, hypoxia, overcrowding and starvation, respectively, while after 144 h did not show significant difference among treatments compared with control group. In contrast, the values of T₃ and T₄ observed reduction with significant difference that T₃ ranged between the highest value 122.12 ng/ml for control group to lowest value of starvation group 94.35, 93.81 and 88.46 ng/ml after 24, 72 and 144 h. Also, similar trend of results observed in T₄ and blood glucose among treatments. And the enzymatic activity of lactate dehydrogenise (LDH) increased in hypoxic group, while a significant reduction appeared in overcrowding and starved fish compared to control group. The pyruvate kinase (PK) activity decreased in hypoxic group but increased in other group.     

Effect of ammonia on respiratory functions of blood of Tilapia zilli

The present paper attempts an examination of different changes of blood respiratory properties when Tilapia zilli is exposed to ammonia in three sublethal concentrations (1.1, 2.2 and 3.3 mg NH₃ l⁻¹) for 2 weeks. The results revealed that oxygen and carbon dioxide partial pressures (P_O2 and P_CO2) were changed differently and irregularly both in the caudal artery and in the heart. The acid–base status (pH, HCO⁻₃, TCO₂ and base excess) of arterial and venous blood changed towards alkalosis during the first week. These changes were exaggerated during the second week of ammonia exposure. O₂ saturation of arterial blood was decreased, while that of venous blood was increased due to the disturbances in blood gas transport and exchange mechanisms and in the acid–base status. The oxygen equilibrium curve was shifted to the left and P₅₀ was decreased during most of the experimental periods.     

The one-stage preauricular flap for male pattern baldness: long-term results and risk factors

Following a review of the operative technique for a single-stage vertical flap for reconstruction of the frontal hairline, we present a series of 156 such flaps with a minimum follow-up of 6 months. Risk factors for necrosis or alopecia of the distal end of the flap include retroauricular design and cigarette smoking. There was not a single case of necrosis in nonsmokers with flaps shorter than 16 cm. Finally, we demonstrate that the final appearance of the donor site is directly related to the tension under which it is closed.     

Microtiter plate assay for the measurement of glutathione and glutathione disulfide in large numbers of biological samples

By combining the least complicated and expedient methods of sample handling with the sensitivity and specificity of the GSH assay by enzymatic recycling and the small volumes and software capabilities of microtiter plate technology we have devised a rapid, sensitive, and easy assay for GSH and GSSG in biological samples. The assay is sensitive to 5 pmol in sample volumes of 50 microliters, although other volumes could be used. The use of a computer-driven microplate with software capable of linear kinetic data storage and analysis on each well, Maxline series microplate readers and Softmax software, enables the user not only to assay large numbers of samples per day but also to have immediate calculated results. We suggest by examples that measurements of total GSH as well as changes in GSH:GSSG in vitro and in vivo are feasible with this technology.     

Selenium Overcomes Doxorubicin Resistance in Their Nano-platforms Against Breast and Colon Cancers

Biological Trace Element Research - Colon cancer in men and breast cancer in women are regarded as major health burdens, accounting for majority of cancer diagnoses globally. Doxorubicin (DOX)...     

Transfer of Rolf S3-S4 Linker to hERG Eliminates Activation Gating but Spares Inactivation

Studies in Shaker, a voltage-dependent potassium channel, suggest a coupling between activation and inactivation. This coupling is controversial in hERG, a fast-inactivating voltage-dependent potassium channel. To address this question, we transferred to hERG the S3-S4 linker of the voltage-independent channel, rolf, to selectively disrupt the activation process. This chimera shows an intact voltage-dependent inactivation process consistent with a weak coupling, if any, between both processes. Kinetic models suggest that the chimera presents only an open and an inactivated states, with identical transition rates as in hERG. The lower sensitivity of the chimera to BeKm-1, a hERG preferential closed-state inhibitor, also suggests that the chimera presents mainly open and inactivated conformations. This chimera allows determining the mechanism of action of hERG blockers, as exemplified by the test on ketoconazole.