Expression of monocarboxylate transporter 1 (MCT1) in the dog intestine

In this study, the expression and distribution of monocarboxyolate transporter 1 (MCT1) along the intestines (duodenum, jejunum, ileum, cecum, colon and rectum) of dogs were investigated at both the mRNA and protein levels. The expression of MCT1 protein and its distribution were confirmed by Western blotting and immunohistochemical staining using the antibody for MCT1. We identified mRNA coding for MCT1 and a 43-kDa band of MCT1 protein in all regions from the duodenum to the rectum. Immunoreactive staining for MCT1 was also observed in epithelial cells throughout the intestines. MCT1 immunoreactivity was greater in the large intestine than in the small intestine. MCT1 protein was predominantly expressed on the basolateral membranes along intestinal epithelial cells, suggesting that MCT1 may play an important role in lactate efflux and transport of short-chain fatty acids (SCFAs) to the bloodstream across the basolateral membranes of the dog intestine.     

Reproductive phenotypes in mice with targeted disruption of the 20alpha-hydroxysteroid dehydrogenase gene

In the corpus luteum of rats and mice, 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) catalyzes the conversion of progesterone to a biologically inactive metabolite, 20alpha-dihydroprogesterone (20alpha-OHP). The reduction of progesterone by 20alpha-HSD is believed to be important for functional luteolysis in these rodent species. In addition to the corpus luteum, expression of 20alpha-HSD has been demonstrated in tissues such as the placenta, endometrial epithelia, and fetal skin, although the roles it plays in the latter tissues remain to be determined. To determine the contribution of 20alpha-HSD to functional luteolysis and to the rodent reproductive system more generally, we generated a strain of mice with targeted disruption of the 20alpha-HSD gene. In the 20alpha-HSD-/- mice we obtained, which lacked the genomic region essential for catalytic reaction, neither 20alpha-HSD activity in the corpus luteum nor an increase in the serum concentrations of 20alpha-OHP during pseudopregnancy or pregnancy was detected. The durations of the estrous cycle, pseudopregnancy, and pregnancy were significantly prolonged in the 20alpha-HSD-/- mice, although the serum progesterone levels decreased to levels low enough for delivery of pups at term of pregnancy. In addition, the number of pups, especially live pups, was markedly decreased in the 20alpha-HSD-/- mice. These findings suggest that the role of 20alpha-HSD in functional luteolysis is relatively minor but that it is involved in the survival of newborn mice.     

Abnormal distribution of chromosomes in the first division of nuclear transferred mouse embryos

The majority of somatic cell nuclear transferred (SCNT) embryos die before or after implantation. Many studies have focused on morphological remodeling of the donor nucleus and its associated cytoskeletal structures in the early events of nuclear transfer. However, little is known about the 2-cell stage of SCNT embryos after the first division. In this study, we compared the morphological status of chromosomal division during the 1-cell stage to the 2-cell stage in SCNT embryos with that in intracytoplasmic sperm injection (ICSI) embryos. The microtubules and cytoplasmic asters, which are related to chromatin segregation, disappeared at the pronuclear stage, although formation of the first mitotic spindle was normal in both the SCNT and ICSI embryos. However, nuclear fragmentation was observed in 30% of the 2-cell SCNT embryos and 12% of the 2-cell ICSI embryos. Nuclear fragmentation was present in both blastomeres of these embryos. No apoptotic DNA fragmentation was observed in TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) assays for either the SCNT or ICSI embryos. In both the SCNT and ICSI embryos, the distribution of chromosomes in the first mitotic spindle was disturbed during the process of division from the 1-cell stage to the 2-cell stage. These results suggest that loss of SCNT embryos just before or after implantation may be due to an abnormal chromosome distribution at the 2-cell stage.     

Histochemical and immunohistochemical characterization of chordoma in ferrets

Chordomas of the tip of the tail in 6 ferrets were examined using histopathological, histochemical and immunohistochemical procedures. Histopathologically, round neoplastic cells containing numerous cytoplasmic vacuoles of varying sizes, categorized as “physaliphorous cells”, were observed in the amorphous eosinophilic or pale basophilic myxoid stroma. Physaliphorous cells were arranged in lobules and in a “chordoid” or “cobblestone” manner. The neoplasms were diagnosed as benign chordoma without local invasion and metastasis. Histochemically, the cytoplasm of small neoplastic cells was positive for periodic acid-Schiff stain and alcian blue (AB) pH 2.5 and pH 1.0 stains, but negative for hyaluronidase digestion-AB pH 2.5 stain. All neoplastic cells were strongly stained with colloidal ion, negative for high iron diamine AB pH 2.5 and toluidine blue pH 2.5 stains, and positive for Mayer’s mucicarmine stain. Immunohistochemistry using antibodies directed against low-molecular-weight cytokeratins (CK18, CK19 and CK20), vimentin and mucin core protein (MUC5AC) revealed that neoplastic cells had both epithelial and mesenchymal elements. The expression of low-molecular-weight cytokeratins suggests that neoplastic cells acquired the properties of glandular epithelial cells and produced epithelial mucus. Furthermore, the expression of cytokeratins, vimentin, S100 protein, brachyury and epithelial membrane antigen indicates that the neoplasms were equivalent to the classic type of human chordoma. Therefore, immunohistochemistry using these antibodies can be useful for the characterization of ferret chordoma.     

Cesium radioactivity in peripheral blood is linearly correlated to that in skeletal muscle: Analyses of cattle within the evacuation zone of the Fukushima Daiichi Nuclear Power Plant

The accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) released a large amount of radioactive substances into the environment. Furthermore, beef contaminated with radioactive cesium above the 500 Bq/kg safety standard was circulated in the food chain in 2011. Japanese consumers remain concerned about the safety of radioactively contaminated food. In our previous study, we detected a linear correlation between radioactive cesium (¹³⁷Cs) activity in blood and muscle around 500 to 2500 Bq/kg in cattle. However, it was unclear whether the correlation was maintained at a lower radioactivity close to the current safety standard of 100 Bq/kg. In this study, we evaluated 17 cattle in the FNPP evacuation zone that had a ¹³⁷Cs blood level less than 10 Bq/kg. The results showed a linear correlation between blood ¹³⁷Cs and muscle ¹³⁷Cs (Y = 28.0X, R² = 0.590) at low radioactivity concentration, indicating that cesium radioactivity in the muscle can be estimated from blood radioactivity. This technique would be useful in detecting high‐risk cattle before they enter the market, and will contribute to food safety.     

Electrical manipulation of magnetization reversal in a ferromagnetic semiconductor

We report electrical manipulation of magnetization processes in a ferromagnetic semiconductor, in which low-density carriers are responsible for the ferromagnetic interaction. The coercive force HC at which magnetization reversal occurs can be manipulated by modifying the carrier density through application of electric fields in a gated structure. Electrically assisted magnetization reversal, as well as electrical demagnetization, has been demonstrated through the effect. This electrical manipulation offers a functionality not previously accessible in magnetic materials and may become useful for reversing magnetization of nanoscale bits for ultrahigh-density information storage.     

Expression analysis of defense-related genes in wild kiwifruit (Actinidia rufa) tolerant to bacterial canker

Journal of General Plant Pathology - Kiwifruit bacterial canker, which is caused by Pseudomonas syringae pv. actinidiae biovar 3 (Psa3), is found throughout kiwifruit-growing countries. Here, we...     

Comparison of acute inhalation toxicity of sulfuric acid by the inhalation and intratracheal instillation methods

Recently, intratracheal instillation has been focused on as a simple, low-cost alternative to the inhalation method. In this study, intratracheal instillation of sulfuric acid, a typical acidic compound, was performed to compare the acute toxicity of acidic compounds that could cause damage to the respiratory system between intratracheal instillation and inhalation. Sulfuric acid was administered to male rats at doses of 0.7, 2, 7, 20, and 60 mg/kg by dividing the total dose into four doses. General condition and body weight were examined up to 14 days after administration, and macropathological and histopathological examinations were performed. The half-lethal dose was then estimated. All animals administered 20 and 60 mg/kg sulfuric acid and one animal administered 2 mg/kg sulfuric acid died within 4 h after administration. No abnormalities were observed in other animals. At 20 and 60 mg/kg, multiple red foci or diffuse red areas were macroscopically observed in the lungs. In these lesions, histopathologically, clefts between the mucosal epithelium and basement membrane and necrosis of the alveolar epithelium were observed. Deaths in these groups may have resulted from lung injury. No notable changes were observed in other animals. Therefore, the half-lethal dose of sulfuric acid by intratracheal instillation was estimated as 7–20 mg/kg. The acute toxicity by intratracheal instillation was evaluated with two-fold sensitivity since the exposure at the half-lethal sulfuric acid concentration in inhalation studies was calculated as 43.2 mg/kg.     

Purification and characterization of polyphenol oxidase from cauliflower (Brassica oleracea L.)

Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).