Chromium(Ⅵ) Reduction in Wheat Rhizosphere

Reduction of Cr(Ⅵ) to Cr(Ⅲ) were studied in a fresh wheat rhizosphere soil (Kuroboku, high humic andosol) pretreated with a basal fertilizer consisting of (NH4)2SO4, P2O5 and KH2PO4 and with K2Cr2O7 by using a rhizobox system. It was found that rhizosphere exerted a positive effect on Cr(Ⅵ) reduction.Part of the reason was the decrease of pH in the rhizosphere due to application of (NH4)2SO4, implying that application of physiologically acid fertilizers would reduce Cr(Ⅵ) toxicity to plants.     

Detection of monoclonal integration of bovine leukemia virus proviral DNA as a malignant marker in two enzootic bovine leukosis cases with difficult clinical diagnosis

Monoclonal integration of bovine leukemia virus (BLV) proviral DNA into bovine genomes was detected in peripheral blood from two clinical cases of enzootic bovine leukosis (EBL) without enlargement of superficial lymph nodes. A BLV-specific probe hybridized with 1 to 3 EcoRI and HindIII fragments in these 2 atypical EBL cattle by Southern blotting and hybridization, as well as in 3 typical EBL cattle. The probe also hybridized to a large number of EcoRI and HindIII fragments in 5 cattle with persistent leukosis. These results suggest that the detection of monoclonal integration of BLV provirus into the host genome may serve as a marker of monoclonal proliferation and malignancy in difficult to diagnose EBL cattle.     

Effect of ruminal dosing of mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in Holstein steers fed a concentrate diet

This experiment was conducted to determine the effect of ruminal dosing of a mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in steers fed a concentrate diet at maintenance level. Animals were dosed three Rumen Faibu (RF) per head through the rumen fistulae (RF treatment) and not dosed (control) in a change‐over design. The organic cell wall content of the concentrate diet was 12.7% of dry matter. Daily time spent on rumination was very short in both treatments with 24 min in RF treatment and 15 min in control. The turnover rate of ruminal fluid in RF treatment was higher than that in control. There were no differences in ruminal pH and total volatile fatty acid concentration between RF treatment and control. Acetic and butyric acid concentrations were not different between the treatments. Propionic acid concentration tended to be higher in the animals on RF treatment than in control animals. The RF dosing in Holstein steers fed a low fiber diet did not affect the rumination time, but increased rumen digesta passage rate and ruminal propionic acid production.     

Tooth brushing inhibits oral bacteria in dogs

In this study, scaling, polishing and daily tooth brushing were performed in 20 beagle dogs, and the number of oral bacteria was determined using a bacterial counter. The dogs were randomized into the scaling (S), scaling + polishing (SP), scaling + tooth daily brushing (SB) and scaling + polishing + tooth daily brushing (SPB) groups. Samples were collected from the buccal surface of the maxillary fourth premolars of the dogs immediately after scaling and every week thereafter from weeks 1 to 8. Throughout the study, the number of bacteria was significantly lower in the SB and SPB groups compared with the S group. The findings suggest that daily tooth brushing inhibited oral bacterial growth in the dogs.     

The effect of estrogen on phosphorylation of prolactin in the mouse pituitary gland

Several studies have indicated that prolactin (PRL) assumes oligomeric, proteolytically cleaved, phosphorylated and glycosylated forms. Phosphorylated PRL (PPRL) is considered to be the most important posttranslationally modified form in the rat. In the present study, we examined whether or not PRL is present in the mouse pituitary gland in the phosphorylated form. Mouse pituitary PRL was digested with acid phosphatase, resolved by two-dimensional gel electrophoresis, stained with Coomassie brilliant blue, and then immunoblotted against the anti-PRL, anti-phosphoserine and anti-phosphothreonine antibodies. We also examined whether PRL is phosphorylated by protein kinases and semi-quantified the ratios of PPRL to PRL in the pituitary gland. The results indicated that three types of PRL are present in the pituitary glands of both male and female mice. One was non-phosphorylated (isoform 1), and the other two were immunoreactive to anti-phosphoserine (isoform 2) and/or anti-phosphothreonine (isoform 3) antibodies. The ratio between isoforms 2 and 1 of the 30-day-old female mice was higher than that of the 20-day-old female mice. However, the ratios among the three isoforms in the male pituitary glands did not differ with age. The ratio of PPRL to isoform 1 was obviously reduced after ovariectomy (OVX), and it recovered with estrogen replacement. These results suggest that estrogen influences PRL phosphorylation in female mice.     

叶片尾缘加弯板垂直轴风力机转矩特性数值模拟

文章提出一种在叶片尾缘加装弯板改善直线翼垂直轴风力机叶片周围流场,提高风力机转矩特性的方法。选取NACA0024和NACA0012两种直线翼垂直轴风力机常用翼型,利用数值模拟计算包括不加装弯板在内具有7种弯板长度2叶片直线翼垂直轴风力机输出转矩特性和静态起动转矩特性。结果表明,在NACA系列对称翼型尾缘加弯板叶片可在一定程度上改善直线翼垂直轴风力机输出转矩特性和静态起动特性。叶片尾缘加装弯板后可在某些旋转角下改变叶片上下表面压力分布,减少涡旋和流动分离产生,提高叶片气动特性,改善风力机转矩特性。研究发现,弯板长度为弦长40%风力机转矩特性改善效果最好,最大输出转矩系数较无弯板风力机提高17%,静态平均起动转矩提高26.4%。     

Spatial distribution of soil carbon and nitrogen storage and forest productivity in a watershed planted to Japanese cedar (Cryptomeria japonica D. Don)

Digital terrain modeling was used to evaluate landscape-level spatial variation of soil C and N storage and site productivity in Japanese cedar (Cryptomeria japonica D. Don) stands. Soil C and N storage were measured in samples from surface soils (0–25 cm depth) of 29 Japanese cedar stands in the 205-ha Myougodani watershed, Toyama Prefecture. The site index (C. japonica tree height at age 40 years) was used as a measure of forest productivity. Seven terrain attributes (elevation, slope gradient, aspect, profile curvature, plan curvature, openness, and wetness index) were calculated from a digital elevation model. Soil C and N storage were negatively correlated with slope gradient and positively correlated with openness. Variation in the site index was closely related to the wetness index. The prediction models using terrain attributes as explanatory variables explained 50% of the variability in soil C storage, 53% of the variability in soil N storage, and 75% of the variability in site index. This result demonstrated that this technique is useful for estimating the spatial distribution of soil properties and productivity in forest landscapes. On the other hand, there was no correlation between site index and soil C and N storage. Use of the prediction models in a geographic information system revealed that the spatial distribution of forest productivity differed considerably from those of soil C and N storage.     

A clinical case of severe anemia in a sheep coinfected with Mycoplasma ovis and 'Candidatus Mycoplasma haemovis' in Hokkaido, Japan

A 2-year-old East Friesian sheep imported from Australia exhibited severe anemia after contagious pustular dermatitis in Hokkaido, Japan. Hemoplasma infection was confirmed in blood smears. Both Mycoplasma ovis and 'Candidatus Mycoplasma haemovis' were detected by PCR and sequence analyses. In the epidemiological analysis, dual pathogens were detected in 6 of 12 (50.0%) sheep imported from Australia with the infected ewe at the same time, 1 of 5 (20.0%) sheep introduced from a domestic farm in Hokkaido, and in 1 of 16 (6.3%) sheep from an epidemiologically unrelated ranch. It is the first clinical case of sheep to confirm coinfection of these pathogens in Japan.     

Effects of coumestrol administration to maternal mice during pregnancy and lactation on renal Ca metabolism in neonatal mice

The present study was conducted to clarify the effects of coumestrol administration to maternal mice during pregnancy and lactation on serum Ca and Ca metabolism in their neonatal mice. From 6.5 to 16.5 days post coitus and from 3 to 10 days after parturition, maternal mice were administered at 200 µg/kg body weight/day of coumestrol. Coumestrol administration did not affect weight gains, serum Ca and the expression of vitamin D receptor (VDR) protein in the kidney of neonatal mice, but weight gains of maternal mice were decreased by coumestrol administration. Coumestrol administration increased the messenger RNA (mRNA) expressions of epithelial Ca channels 1 (ECaC1) and VDR in the kidney of neonatal mice, and also increased the mRNA expressions of ECaC2 in the kidney and small intestine of male neonatal mice. The mRNA expressions of ECaC1, ECaC2, calbindin‐D_9k (CaBP‐9k) and estrogen receptor (ER)α in the kidney and VDR in the small intestine of male neonatal mice were higher than those of female mice. Thus, coumestrol administration to maternal mice during pregnancy and lactation may affect renal Ca metabolism in neonatal mice, especially male neonatal mice via maternal milk.     

Expression of hepatitis C virus core protein associated with malignant lymphoma in transgenic mice

Hepatitis C virus (HCV) is a major causative agent for chronic liver diseases leading to hepatocellular carcinoma (HCC) and has also been suggested to be a possible etiologic factor for different lymphoproliferative diseases, including mixed cryoglobulinemia (MC) and B-cell non-Hodgkin's lymphoma (NHL). To understand the roles of HCV core protein in the pathogenesis of HCV related diseases, we produced two lines of the transgenic mice (HC82310 and HC9053) that express the HCV core transgene. One of the lines, HC9053, developed malignant lymphoma (ML, follicular center cell type) with a high frequency (80%) at the ages over 20 months. Hepatocellular adenoma was also observed in this line of transgenic mouse. We demonstrated expression of HCV core protein and mRNA in the liver of transgenic mice, and also detected the core mRNA in the enlarged lymph nodes of the transgenic mice which developed ML. These results suggest that the core protein may play an important role in the development of ML, and that the HC9053 transgenic mice provide suitable models for understanding the mechanism of HCV-related lymphoproliferative diseases.