Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 degrees C, 50% RH; heat stress: 35 degrees C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.     

Channel inception in cohesionless sediment by seepage erosion

This study presents a series of systematic experiments on channelization by seepage erosion with various sediment layer depths and chamber slopes. When the depth of the sediment layer increases, the threshold discharge for channel initiation decreases, but the channel width increases. This is due to the fact that an increase in the weight of sediment induces an increase in a gravitational driving force along the chamber bed. When the chamber slope increases, we also found a similar effect as an increase in the sediment layer depth that the threshold discharge decreases, but the width increases. While channel bifurcation was never found in the previous study using plastic pellets as sediment, it was observed in many experiments in the present study, in which very coarse sand was used. We hypothesized that the characteristics of groundwater flow field and the resistibility of sediment material to slope failure play important roles on the channel bifurcation.     

Standard infrared absorption spectrum of betaine and optimal conditions for its measurement

The infrared absorption (IR) spectrum is often used as a standard reference in identification tests of food additives in Japan. In the case of betaine, many different IR spectra have been reported and, therefore, it is necessary to establish an IR spectrum that is reproducible and reliable enough to be used as a standard for identification. In the present study, suitable conditions to obtain a standard IR spectrum were examined from various viewpoints, including pretreatment, selection of method, and measuring technique. The KBr disk method, which has generally been used to identify betaine, was found to be humidity-dependent, and there was also an interaction between betaine and KBr. A reproducible IR spectrum suitable as a standard could be obtained by drying betaine at 105 degrees C for 3 hours over phosphorus pentoxide, and then measuring the IR spectrum by the liquid paraffin (Nujol) paste method.     

Effect of components extracted from okara on the physicochemical properties of soymilk and tofu texture

ABSTRACT:  The physicochemical properties of soymilk and the texture of tofu were compared with regard to 2 kinds of soymilk, one of which was prepared by squeezing homogenates before heating and the other was prepared by squeezing after heating raw soymilk with okara, residue of soymilk production. Relative particulate protein content and viscosity were higher and pH was lower in the soymilk prepared by the latter method, in which liberated lipid bodies were decreased and more lipids were precipitated with protein after centrifugation, suggesting a change in the interaction between proteins and lipids. A difference in the distribution of proteins and lipids was also implied by analysis with a laser particle size analyzer. The breaking stress of tofu made with 0.30% glucono-delta-lactone increased in accordance with an increase in particulate protein. The calcium and magnesium contents increased in soymilk prepared by squeezing after heating with okara. Viscosity was slightly increased and pH decreased by adding calcium to the soymilk, but the particulate protein content and breaking stress of tofu did not increase significantly. To examine the effect of macromolecules, okara was extracted by boiling and dialyzed. Viscosity and particulate protein content in soymilk increased as the dialyzed extracts of the okara were added. The breaking stress of tofu was increased by adding the dialyzed extracts but excessive amounts of the extracts resulted in softer tofu. Spectra of Fourier-transform infrared spectroscopy and electrophoresis-separated patterns of proteins indicated that the dialyzed extracts contained mainly polysaccharides and the Basic 7S globulin protein.     

Determination of hymexazol in agricultural products by GC-NPD

A method for the determination of hymexazol in agricultural produdcts by gas chromatography with a highly sensitive nitrogen-phosphorus detector (GC-NPD) was investigated. Hymexazol was extracted with acetonitrile, and the acetonitrile layer was separated by salting-out. The water layer was loaded onto a Chem-Elut column. Hymexazol in the water layer was adsorbed on the column, and eluted with ethyl acetate. The acetonitrile layer and the eluate were mixed and evaporated. The residue was dissolved in ethyl acetate, and the sample solution was cleaned up on a C18 column. Hymexazol in the eluate was analyzed by GC-NPD with a high-polarity capillary column (DB-FFAP) and highly deactivated inlet liner.Recoveries of hymexazol spiked in agricultural products (tomato, lemon, soybean and other samples) at the level of 0.1 mug/g ranged from 65.0 to 84.7%. The limit of detection was 0.02microg/g.     

Toll-like Receptor Response to Hepatitis C Virus Infection: A Recent Overview

Hepatitis C virus (HCV) infection remains a major global health burden, causing chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Toll-like receptors (TLRs) are evolutionarily conserved pattern recognition receptors that detect pathogen-associated molecular patterns and activate downstream signaling to induce proinflammatory cytokine and chemokine production. An increasing number of studies have suggested the importance of TLR responses in the outcome of HCV infection. However, the exact role of innate immune responses, including TLR response, in controlling chronic HCV infection remains to be established. A proper understanding of the TLR response in HCV infection is essential for devising new therapeutic approaches against HCV infection. In this review, we discuss the progress made in our understanding of the host innate immune response to HCV infection, with a particular focus on the TLR response. In addition, we discuss the mechanisms adopted by HCV to avoid immune surveillance mediated by TLRs.     

一种用于自律搬运车导航的混合式视觉方法

For the autonomous guided vehicle (AGV) used mainly in unfixed work fields, a machine vision method was proposed for the navigation system, in which a series of navigation-signs are placed along the travel route. The navigation system detects and recognizes these signs, and accordingly informs the travel control system. In order for the navigation to have balanced ability of 1) covering a large area and 2) recognizing details of the sign, the proposed vision method was designed to be a hybrid one, using both the stereo vision and the traditional 2D template matching. The former implemented a coarse recognition function for above 1), and the later implemented a fine recognition function for above 2). The results from the coarse recognition were used in the fine recognition for the gaze control to input suitable 2D image of the signs. Experiments on a prototype system show the feasibility of the proposed hybrid method in achieving the objective specifications for a typicalb AGV.     

1700 nm optical coherence microscopy enables minimally invasive,label-free,in vivo optical biopsy deep in the mouse brain

In vivo, minimally invasive microscopy in deep cortical and sub-cortical regions of the mouse brain has been challenging. To address this challenge, we present ...