Immunohistochemical study of calpain-mediated alpha-crystallin proteolysis in the UPL rat hereditary cataract

The purpose of this study is to examine if microencapsulated PC12 cells may provide long term effects to the hemiparkinsonian rats. A modified technique was used to encapsulate PC12 cells into gelled microspheres. We found that the PC12 cells can survive in the modified microcapsules in vitro. Most of the PC12 cells formed cluster 3 weeks after incubation. The PC12 cell-loaded microcapsules were also examined in vitro. Adult Sprague-Dawley rats, anesthetized with chloral hydrate, were injected unilaterally with 6-hydroxydopamine into the medial forebrain bundle. The effectiveness of this lesion was tested by measuring apomorphine or methamphetamine-induced rotation one month after lesioning. The unilaterally lesioned rats were transplanted with microencapsulated PC12 cells. Results showed that apomorphine and methamphetamine-induced rotations were greatly suppressed after transplantation. One year after the grafting, the animals were anesthetized with urethane for the voltammetric study. Low dose of KCl was directly injected into the grafted striatum through pressure microejection. We found that KCl-induced DA release, as measured by voltammetric techniques, was regenerated in the striatum. The animals were later sacrificed for histological examination. We found that capsules were present in the lesioned striatum one year after grafting. Most of the capsules contained no PC12 cell. However, some capsules were filled entirely with PC12 cells. Taken together, our data suggested that PC12 cells can survive in the capsule in vitro and may provide long-term dopaminergic effects to the hemiparkinsonian rats.     

ONO-5046 is a potent inhibitor of neutrophil elastase in human pleural effusion after lobectomy

The imbalance of neutrophil elastase and alpha1-antitrypsin in pleural effusion after lobectomy and the effects of the neutrophil elastase inhibitors, sodium N-[2-[4-(2,2-Dimethylpropionyloxy)phenyl-sulfonylamino]benzo yl]aminoacetic acid (ONO-5046) and purified alpha1-antitrypsin, on neutrophil elastase activity were determined. The amount of neutrophil elastase complexed to alpha1-antitrypsin, measured by an enzyme-linked immunosorbent assay, was 170 times higher in pleural effusion than in blood 3 h after lobectomy. The alpha1-antitrypsin levels measured by laser nephelometry did not increase in either blood or pleural effusion. Although neutrophil elastase activity, measured by the hydrolysis of succinyl-(Ala)3-p-nitroanilide, was not detected in blood, it was increased in pleural effusion 3 h and 24 h after lobectomy. ONO-5046, but not alpha1-antitrypsin, reduced the neutrophil elastase activity in pleural effusion. There is an imbalance of neutrophil elastase and alpha1-antitrypsin in pleural effusion after lobectomy. ONO-5046 is a potent inhibitor of neutrophil elastase activity in human pleural effusion.     

Quantitative in situ hybridization of three gonadotropin-releasing hormone-encoding mRNAs in castrated and progesterone-treated male tilapia

We investigated the effects of castration and progesterone administration on the three gonadotropin-releasing hormone (GnRH)-encoding mRNAs in sexually mature male tilapia Oreochromis niloticus. In situ hybridization histochemistry was performed using 35S-labeled antisense oligonucleotide probes complementary to salmon-, seabream-, and chicken II-GnRH cDNAs to quantify cellular GnRH mRNA expression in the terminal nerve ganglia (nucleus olfactoretinalis), preoptic area, and midbrain tegmentum of animals castrated for 2 weeks and injected intraperitoneally with sesame oil or progesterone. Castration significantly elevated salmon-GnRH mRNA but not seabream- or chicken II-GnRH mRNA levels. Progesterone treatment had no effect on salmon-, seabream-, or chicken II-GnRH mRNA levels. Comparisons between intact, castrated, and progesterone-treated animals showed no change in the total volume of nucleus olfactoretinalis, cell sizes, and total numbers of cells expressing GnRH mRNA within the midbrain and preoptic area. These results demonstrate that salmon-GnRH but not seabream- or chicken II-GnRH-synthesizing neurons are under a gonadal steroid negative feedback control and that progesterone might not be the main hormone regulating the three GnRH-encoding mRNAs in the male tilapia.     

Cathodoluminescence study of AlGaAs/GaAs multilayers grown on ridge-type triangles on GaAs (111)A substrates

We have studied the cathodoluminescence of AlxGa1-xAs/GaAs multilayers grown on ridge-type triangles by molecular beam epitaxy. The compositional variation of Al, as well as the distribution of impurity and/or defect, was revealed by variations in the cathodoluminescence spectra and images. The Al composition in an AlxGa1-xAs layer was highest in the (111)A facet and decreased in the order (100), (411)A, (111)-delta and (110) facets. On the other hand, the carbon concentration was highest in the (411)A facet and decreased in the order (111)A, (111)-delta, (100) and (110) facets. It should be noted that the (111)-delta facet has a significant effect on the redistribution of Al. Although our ridge-type triangles are rather large for the quantum structures, these data have elucidated the self-organization mechanism of the AlxGa1-xAs/GaAs system and have yielded information on the design of quantum structures. We conclude that cathodoluminescence observation is a powerful tool for studying the compositional variation or band structure of three-dimensional microscale or nanoscale construction.     

Mössbauer studies and magnetic properties of SnO2 doped with Fe

Transparent conducting SnO₂ powders doped with 10% Fe content were prepared by a polymerized complex method under acidic solutions, and annealed finally at 550 °C, and at 600 °C. These samples were characterized by X-ray diffraction, magnetization, and Mössbauer spectrometry at room temperature. Rutile SnO₂ phase was obtained for both samples, and the crystallite sizes were in the range of 13-14 nm. Both samples exhibit magnetization and the saturation magnetization was smaller for the sample annealed at 600 °C than for sample annealed at 550 °C. Room temperature Mössbauer spectra for both samples showed the presence of two different paramagnetic iron sites but no magnetic sextets. These results suggest that ferromagnetism originates from magnetic defects and not directly from iron ions.     

DC interruption characteristic of vacuum circuit breaker

A high‐speed vacuum circuit breaker (HSVCB) has been investigated. HSVCB makes high‐frequency current superimposed on a fault current so that the current is forced to be zero and is interrupted. Its interruption performance is considered to be dependent on the rate of change of the current (di/dt). As a fundamental research, we investigated the di/dt– dv/dt characteristics and the insulation recovery characteristic after interrupting the counter‐pulse current for various contact materials of AgWC, CuW, and CuCr. The results revealed that the case where the gap length is larger is better in a current interruption performance. Moreover, it was found that di/dt is not dependent on the insulation recovery characteristics, but the magnitude of interruption current is of great influence. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 17– 25, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20362     

Microstructure and mechanical properties of ZrO2-2 mol% Y2O3 ceramics

The microstructure and mechanical properties of ZrO₂-2 mol% Y₂O₃ ceramics were studied on samples prepared by cold isostatic pressing and pressureless sintering. It was shown that the density of the alloy increases with increasing sintering temperature. The Vickers hardness decreases with the appearance of the monoclinic phase and increasing its content. Compared with the single tetragonal phase, the (t + m) dual-phase structure with microcracks has a much higher fracture toughness (16·5 MPa√m) because of a complex mechanism of toughening (transformation, microcracks and residual stresses).