Total glutathione and glutathione reductase in bovine erythrocytes and liver biopsy

The goal of the present study was to measure the total glutathione level and glutathione reductase activity in bovine erythrocytes and liver biopsy. Five cows were injected intraperitoneally with DL-ethionine (12.5 mg/kg B.W.), and two control cows were injected with normal saline (0.9% NaCl). Ultrasonography guided liver biopsy, and blood samples were collected at 0, 4, 7 and 10 days after injection. The hepatic total glutathione level was significantly increased on Days 7 (p<0.05) and 10 (p<0.01), and hepatic glutathione reductase activity was significantly increased on Days 4 (p<0.05), 7 (p<0.01) and 10 (p<0.01). There were insignificant changes in the erythrocytic total glutathione level. The present study demonstrated that liver biopsy is a valuable tool for detecting oxidative stress and for diagnosing hepatic dysfunction in cattle from the viewpoint of the status of glutathione and glutathione reductase.     

Early pathophysiologic feature of arthropathy in juvenile dogs induced by ofloxacin, a quinolone antimicrobial agent

Arthropathy in dogs induced by ofloxacin, a quinolone antimicrobial agent, was pathophysiologically investigated. In the in vivo studies, ofloxacin was administered orally once or twice at 20 mg/kg/day to male juvenile (3-month-old, n=3) or adult (36-month-old, n=2) dogs, and the humeral and femoral heads were examined pathologically. Unlike adult dogs, fluid-filled vesicles were macroscopically observed on the articular surfaces of one juvenile dog 24 hours after a single treatment with ofloxacin. These lesions were seen in all juvenile dogs by twice dosing. Microscopically, fissures or cavity formations in the middle zone of the articular cartilage were noted only in juvenile dogs. Furthermore, the cartilage matrix from the abnormal area to the articular surface showed a decreased safranin-O staining intensity, suggesting proteoglycan depletion. Ultrastructurally, chondrocytes in the middle zone of juvenile dogs displayed dilatation of the cisternae in the rough endoplasmic reticulum as an initial hallmark. In the in vitro studies, chondrocytes isolated from the articular cartilage of naive juvenile dogs were exposed to ofloxacin at 6.3-100 microg/ml for 24 hours. Although no changes were noted in the deoxyribonucleic acid synthesis, protein synthesis, or proteoglycan release at concentrations of up to 100 microg/ml, the proteoglycan synthesis was evidently decreased in a dose-dependent manner from 12.5 microg/ml. The results obtained suggest that the inhibitory action of ofloxacin on proteoglycan syntheses in the chondrocytes may largely contribute to the early morphologic features in the articular cartilage of the juvenile dog.     

The neural basis of intuitive best next-move generation in board game experts

The superior capability of cognitive experts largely depends on quick automatic processes. To reveal their neural bases, we used functional magnetic resonance imaging to study brain activity of professional and amateur players in a board game named shogi. We found two activations specific to professionals: one in the precuneus of the parietal lobe during perception of board patterns, and the other in the caudate nucleus of the basal ganglia during quick generation of the best next move. Activities at these two sites covaried in relevant tasks. These results suggest that the precuneus-caudate circuit implements the automatic, yet complicated, processes of board-pattern perception and next-move generation in board game experts.     

Neuronal correlates of goal-based motor selection in the prefrontal cortex

Choosing an action that leads to a desired goal requires an understanding of the linkages between actions and their outcomes. We investigated neural mechanisms of such goal-based action selection. We trained monkeys on a task in which the relation between visual cues, action types, and reward conditions changed regularly, such that the monkeys selected their actions based on anticipated reward conditions. A significant number of neurons in the medial prefrontal cortex were activated, after cue presentation and before motor execution, only by particular action-reward combinations. This prefrontal activity is likely to underlie goal-based action selection.     

A new source of basaltic meteorites inferred from Northwest Africa 011

Eucrites are a class of basaltic meteorites that share common mineralogical, isotopic, and chemical properties and are thought to have been derived from the same parent body, possibly asteroid 4 Vesta. The texture, mineralogy, and noble gas data of the recently recovered meteorite, Northwest Africa (NWA) 011, are similar to those of basaltic eucrites. However, the oxygen isotopic composition of NWA011 is different from that of other eucrites, indicating that NWA011 may be derived from a different parent body. The presence of basaltic meteorites with variable oxygen isotopic composition suggests the occurrence of multiple basaltic meteorite parent bodies, perhaps similar to 4 Vesta, in the early solar system.     

Therapeutic effect of anti-TNF-α antibody and levofloxacin (LVFX) in a mouse model of enterohemorrhagic Escherichia coli O157 infection

The ability of an anti-TNF-α antibody to confer protection against enterohaemorrhagic Escherichia coli (EHEC) O157 was investigated in germfree IQI mice. The use of an antibiotic levofloxacin (LVFX) alone or with the antibody was also studied. Protection included an increase in survival rate. Treatment with the anti-TNF-α antibody inhibited the histological signs associated with EHEC infection but did not prevent the colonization of EHEC or production of Shiga toxin (Stx). No clinical signs were observed and EHEC was completely eliminated in the mouse model receiving both anti-TNF-α antibody and LVFX. Anti-TNF-α antibody suppressed inflammatory cytokine response in the mouse kidney and brain by EHEC infection.     

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.     

Signature-tagged mutagenesis of Vibrio vulnificus

Vibrio vulnificus is the causative agent of primary septicemia, wound infection and gastroenteritis in immunocompromised people. In this study, signature-tagged mutagenesis (STM) was applied to identify the virulence genes of V. vulnificus. Using STM, 6,480 mutants in total were constructed and divided into 81 sets (INPUT pools); each mutant in a set was assigned a different tag. Each INPUT pool was intraperitoneally injected into iron-overloaded mice, and in vivo surviving mutants were collected from blood samples from the heart (OUTPUT pools). From the genomic DNA of mixed INPUT or OUTPUT pools, digoxigenin-labeled DNA probes against the tagged region were prepared and used for dot hybridization. Thirty tentatively attenuated mutants, which were hybridized clearly with INPUT probes but barely with OUTPUT probes, were negatively selected. Lethal doses of 11 of the 30 mutants were reduced to more than 1/100; of these, the lethal doses of 2 were reduced to as low as 1/100,000. Transposon-inserted genes in the 11 attenuated mutants were those for IMP dehydrogenase, UDP-N-acetylglucosamine-2-epimerase, aspartokinase, phosphoribosylformylglycinamidine cyclo-ligase, malate Na (+) symporter and hypothetical protein. When mice were immunized with an attenuated mutant strain into which IMP dehydrogenase had been inserted with a transposon, they were protected against V. vulnificus infection. In this study, we demonstrated that the STM method can be used to search for the virulence genes of V. vulnificus.     

Proposal of new return flow analysis by replacement-in-order method for paddy irrigation water

Return flow and repeated use of irrigation water for paddies is the most important issue in the Asian monsoon region, because sometimes this water is applied in greater quantity than that of evapotranspiration plus percolation. A new return flow analysis, the “replacement-in-order method”, which introduces a unique numbering system for very complicated irrigation and drainage networks, is proposed for the main canal with the dual purposes of irrigation and drainage. The method is applied to the Shichika irrigation district in the ordinal (season) irrigation period, resulting in a return flow ratio of 45 % for the entire area. Of this amount, 25 % is available for irrigation again. The remaining 20 % is unavailable, because the return flow discharged directly into a canal lacking a diversion weir in the drainage system, or into the Japan Sea. The return flow ratio is very different at the main canal location, from no return flow to 88 %. With the aid of the above method, theoretical analysis of return flow for paddy irrigation water can be done. This includes the deterministic return flow ratio inside and outside the irrigation area, plus precise information of return flow ratios at various main canal locations and routes of irrigation and drainage water.     

The Process and Development Mechanism of Age-related Fibrosis in the Pancreatic Islets of Sprague-Dawley Rats: Immunohistochemical Detection of Myofibroblasts and Suppression Effect by Estrogen Treatment

The mechanism of spontaneous islet fibrosis in Sprague-Dawley rats was investigated. Using sections of the pancreas in naive males aged 26 to 102 weeks old and 26-week-old males injected with β-estradiol 3-benzoate (EB), the incidence of lesions and histological scores of fibrosis were examined in conjunction with immunohistochemistry for α-smooth muscle actin (α-SMA), platelet-derived growth factor receptor-α (PDGFRα) and estrogen receptor-α (ERα). The incidence of islet fibrosis increased in 78-week-old animals compared to the 26-week-old animals, and the incidence of atrophy in the fibrotic islet increased in animals over 52 weeks old. α-SMA and PDGFRα were positively stained mainly in fibrotic/inflammatory islets, and the histological score of α-SMA in the fibrotic islet decreased age-dependently. Notably, α-SMA and PDGFRα were co-expressed in inflammatory islets with a high score at all ages. The positive index of ERα in the EB-treated group increased when compared with that of the naive group. However, it was independent of the existence of fibrosis. In contrast, the score of α-SMA and PDGFRα decreased in the EB-treated group. In conclusion, it was clarified that a part of age-related fibrosis in islets became atrophy with age, and α-SMA-positive myofibroblasts were considered to contribute to the development of fibrosis. Strong PDGFRα stainability in fibrotic/inflammatory islets may imply that myofibroblasts were stimulated by PDGF to produce an extracellular matrix. Although estradiol has been known to suppress fibrosis/inflammation in the islet, nuclear-located ER-dependent signaling was considered not to be involved in the suppression mechanism. EB possibly affected the inhibition of the appearance of myofibroblasts.