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In this study, the micro electro-polishing method was employed to improve the surface quality of microbeams machined by the micro WEDM method and to remove the recast layer. This approach changes the dimensions of the microbeams, as a result of the electrochemical corrosion, in addition to the elimination of the recast layer. To diminish the impact of this process on the dimensional deviation of the fabricated microbeams, the influence of the micro electro-polishing process parameters such as voltage, duration, cathode diameter, and electrolyte composition on the dimensional deviation of microbeams was studied using the Taguchi method. The optimum values of process parameters were determined by the S/N ratios analysis, and the order of parameters importance was determined through analysis of variance of the S/N ratios. It was found that the optimal levels of the process parameters are voltage of 2 V, process duration of 20 s, cathode diameter of 50 mm, and electrolyte composition of 25-5-40 ml (sulfuric-phosphoric-water) within the range of experiments. By using the optimum values of the parameters, the dimensional deviations were found to be 5.23 times lower compared to the average of the results. The importance of process parameters was found to follow this order: electropolishing duration, electrolyte composition, cathode diameter, and process voltage. [ABSTRACT FROM AUTHOR]

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling which is overexpressed in the liver of diabetic animals. The aims of this study were to generate liver-specific PTP1B knockout mice using a PTP1B‑short hairpin RNA (shRNA) plasmid and to investigate the effect of PTP1B inhibition on plasma glucose levels in streptozotocin-induced diabetic mice. We first validated the hydrodynamic tail vein injection in mice using a vector carrying the luciferase gene. Expression of the PTP1B gene was quantified by real-time PCR. The level of phosphorylated Akt was examined by western blot analysis. The injection of the plasmid containing firefly luciferase revealed that the highest transfer of the vector into the liver was obtained 24 h after the injection of 20 µg plasmid. The injection of PTP1B-shRNA, but not the scrambled shRNA plasmid, resulted in a reduction in PTP1B expression levels by up to 84% in the liver of the diabetic mice. Plasma glucose levels following the injection of PTP1B-shRNA remained significantly lower in the diabetic mice for 5 days. In addition, mice receiving PTP1B-shRNA in the basal and insulin-stimulated states had higher levels of Akt phosphorylation in the liver cells compared with mice that were injected with the scrambled sequence (35 and 60%, respectively; p<0.01). Furthermore, PTP1B overexpression was observed in the muscle, liver, adipose, heart and kidney tissues of the diabetic mice. The data from this study demonstrate that PTP1B inhibition may be a promising approach for lowering plasma glucose levels in diabetic patients. However, further studies using non-viral carriers are required to deliver the plasmid safely into the liver.

Development of a specific immunoassay to detect Helicobacter pylori infection in stool samples requires monoclonal antibody against the specific antigen. The aims of this study were to establish monoclonal antibodies against the 26 kDa protein of H. pylori and develop an immunodot blot for their application to recognize H. pylori infection using stool samples. Mice were immunized intraperitoneally with homogenized gel containing the 26 kDa band of cell surface proteins of H. pylori in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The monoclonal antibodies were produced using the hybridoma technique. Reactivity of monoclonal antibodies was tested with the purified 26 kDa antigen and cell surface proteins from cultured H. pylori by ELISA. Furthermore reactivity of monoclonal antibodies was tested on negative and positive stool samples for H. pylori and suspensions of several major bacteria in stool by immunodot blot assay. Five stable hybridoma monoclones were obtained. The concordant reactivity of the monoclonal antibodies with H. pylori present in the stool samples, which had been tested previously using an ACON ELISA kit for H. pylori stool antigen testing, and unreactivity with several different major fecal bacteria in immunodot blotting indicates high specificity of the immunodot blot based on the reaction of produced monoclonal antibodies with the H. pylori antigen in stools. The findings indicate that the novel immunodot blot developed based on new monoclonal antibodies for stool antigens would be useful as a noninvasive method of diagnosing H. pylori infection.