Therapeutic Effects of Quetiapine and 5-HT1A Receptor Agonism on Hyperactivity in Dopamine-Deficient Mice

Some diseases that are associated with dopamine deficiency are accompanied by psychiatric symptoms, including Parkinson’s disease. However, the mechanism by which this occurs has not been clarified. Previous studies found that dopamine-deficient (DD) mice exhibited hyperactivity in a novel environment. This hyperactivity is improved by clozapine and donepezil, which are used to treat psychiatric symptoms associated with dopamine deficiency (PSDD). We considered that DD mice could be used to study PSDD. In the present study, we sought to identify the pharmacological mechanism of PSDD. We conducted locomotor activity tests by administering quetiapine and drugs that have specific actions on serotonin (5-hydroxytryptamine [5-HT]) receptors and muscarinic receptors. Changes in neuronal activity that were induced by drug administration in DD mice were evaluated by examining Fos immunoreactivity. Quetiapine suppressed hyperactivity in DD mice while the 5-HT_1A receptor antagonist WAY100635 inhibited this effect. The number of Fos-positive neurons in the median raphe nucleus increased in DD mice that exhibited hyperactivity and was decreased by treatment with quetiapine and 5-HT_1A receptor agonists. In conclusion, hyperactivity in DD mice was ameliorated by quetiapine, likely through 5-HT_1A receptor activation. These findings suggest that 5-HT_1A receptors may play a role in PSDD, and 5-HT_1A receptor-targeting drugs may help improve PSDD.     

A Study on a Surface Preparation Method for Single-Crystal SiC Using an Fe Catalyst

In this study we investigated the possibility of removing and flattening a single-crystal silicon carbide (SiC) surface by a novel polishing method utilizing hydroxyl radicals (OH radicals) generated on an Fe catalyst surface. To demonstrate the feasibility of preparing a smooth SiC surface, an Fe catalyst and a SiC substrate were rubbed together in H₂O₂ solution, and then the area on the SiC surface that had come into contact with the Fe catalyst was observed in detail. The removal depth and surface microroughness were measured and evaluated using a phase-shift interference microscope and an atomic force microscope (AFM), respectively. Moreover, the removal of material from the SiC surface by utilizing an Fe catalyst rod was examined. The obtained results show that the hard SiC surface can be effectively polished and that the processed area on the SiC surface has atomic-level smoothness along the sliding direction. Moreover, it is shown that the removal characteristics of the SiC substrate depend on process parameters such as the process time, rotation speed, contact load, and concentration of H₂O₂ solution. These results provide useful information for preparing an atomically smooth SiC surface.     

Comparative study of the histochemical properties, collagen content and architecture of the skeletal muscles of wild boar crossbred pigs and commercial hybrid pigs

The histochemical properties, collagen content and architecture of Musculus longissimusthoracis (LT), Musculus pectoralis profundus (PP) and Musculus biceps femoris (BF) were compared in F(1) (half blood) and F(2) (quarter blood) wild boar crossbred pigs and commercial hybrid pigs, and Japanese wild pigs. F(1) pigs showed the lowest growth rate, followed by F(2) pigs. The most rapid growth was shown by the commercial pigs. The percentage weights of LT and PP muscle to body weight were larger in the wild boar crossbred pigs than commercial pigs. The muscles of the crossbred pigs contained type I and IIA myofibers at higher frequency and type IIB at lower frequency than the commercial pigs, except for LT muscle of F(2) pigs. The myofiber diameter in each type of muscle did not differ between pigs except for the smaller type IIA in BF muscle in commercial pigs. The total amount of intramuscular collagen was less in LT muscles than the others. More intramuscular collagen was found in the wild boar crossbred pigs than the commercial pigs in LT and PP muscles. With an increase of collagen content, the perimysial collagen architecture developed but not the endomysial architecture. Traits characteristic of the crossbred pigs seem to be inherited from the wild boar. Our results clarify that cross breeding with wild boar results in pigs with distinctive muscle characteristics in terms of histochemical properties, collagen content and architecture.     

Phenethyl isothiocyanate suppresses nitric oxide production via inhibition of phosphoinositide 3‐kinase/Akt‐induced IFN‐γ secretion in LPS‐activated peritoneal macrophages

Phenethyl isothiocyanate (PEITC), a constituent of many cruciferous vegetables, is well known to have versatile physiological activities, including chemopreventive effects. On the other hand, its anti‐inflammatory effects are poorly reported. Nitric oxide (NO) is associated with a wide variety of inflammatory diseases. In this study, we investigated the effects of PEITC on NO production in LPS‐activated peritoneal macrophages from ICR mice. The signaling pathway of LPS‐induced NO production was examined using neutralizing antibodies [anti‐interferon (IFN)‐γ and anti‐interleukin (IL‐12)] and specific protein kinase inhibitors, as well as others. The activity of PEITC toward NOx production was assessed in mice that received LPS via intraperitoneal administration. The neutralizing antibody of anti‐IFN‐γ, but not anti‐IL‐12, suppressed LPS‐induced NO production by 90%. LY294002, a specific inhibitor of phosphoinositide‐3‐kinase, suppressed Akt and IFN‐γ mRNA expression up‐regulated by LPS, whereas PEITC exhibited a similar inhibition profile. Furthermore, oral administration of PEITC significantly suppressed the serum concentration of NOx in ICR mice. Our results suggest that PEITC suppresses LPS‐induced NO production via inhibition of Akt activation and the resultant decrease in expression of IFN‐γ. This is one of the first reports to demonstrate a marked anti‐inflammatory effect of PEITC following its oral administration.     

Effect of subchronic feeding of genetically modified corn (CBH351) on immune system in BN rats and B10A mice

Subchronic animal feeding studies to examine the effect on the immune system of genetically modified corn CBH351, which contains the Cry9C protein derived from Bacillus thuringiensis subspecies tolworthi, were conducted in female BN rats and B10A mice. The studies were designed to compare the effect of a line of genetically modified corn CBH351 (GM corn) with that of isoline corn (non-GM corn). Heat-treated corn meal was incorporated into the diets of the rats and mice at a concentration of 50%. The study duration was 13 weeks. Growth, food intake, and organ weights of the thymus, spleen, and liver were compared between animals fed the non-GM and GM lines. The histological findings in thymus, spleen, mesenteric lymph nodes, Peyer's patches, small intestines, liver, kidney, and bone marrow, and the presence of Cry9C-specific IgE, IgG, IgG1 and IgA antibodies in serum were also compared. The results showed no significant differences in growth, feeding value, or the histological findings in immunity-related organs between the animals fed the GM and non-GM lines. Production of Cry9 C-specific IgE and IgA was not detected in the serum of either group. Production of Cry9C-specific IgG and IgG1 was slightly increased in the 50% GM groups of BN rats. No Cry9C-specific IgG or IgG1 was detected in the serum of BN rats fed the diet containing 5% GM-corn In conclusion, no immunotoxic activity was detected in the GM-corn-fed rats and mice in this subchronic dietary study.     

Approximate linear amplitude model based algorithm for measuring power system frequency

A novel algorithm for measuring the power system frequency during a very short time is presented in this paper, based on an approximate linear current amplitude model. The presented measuring frequency algorithm is used to get the instantaneous value of the parameter accurately. In the algorithm, the amplitudes of four consecutive sampled currents are supposed to be linear. After rigorous mathematical deduction, including Taylor series expansion and the geometric proportion theorem, the instantaneous frequency could be derived. The errors arising from the linearization in the model are analyzed qualitatively, and then the errors of A/D conversion and Taylor series expansion are considered. By the proposed technique, the measured frequency can be derived easily, quickly, and accurately, without any digital filters. The results after simulation show that the proposed algorithm has high accuracy and noise immunity during power swings and in the normal state. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Electrical Conductivity and Ferromagnetism in a Reduced Graphene–Metal Oxide Hybrid

The rare coexistence of ferromagnetism and electrical conductivity is observed in the reduced graphene oxide–metal oxide hybrids, rGO‐Co, rGO‐Ni, and rGO‐Fe, using chemical reduction with hydrazine or ultraviolet photoirradiation of the graphene oxide–metal complexes, GO‐Co, GO‐Ni, and GO‐Fe. The starting and final materials are characterized by X‐ray photoelectron spectroscopy, transmission electron microscopy (TEM), elemental analysis, Mössbauer spectroscopy, and Raman spectroscopy. In contrast to graphene, where the electrical conductivity and magnetic properties are controlled by carrier (electron or hole) doping, those of graphene oxide can be controlled by complexation with Co²⁺, Ni²⁺, and Fe³⁺ cations through the strong electrostatic affinity of negatively charged graphene oxide towards metal cations. The presence of ferromagnetism and electrical conductivity in these hybrids can promote significant applications including magnetic switching and data storage.     

Matrix remodeling and cytological changes during spontaneous cartilage repair

During the repair of articular cartilage, type I collagen (COL1)-based fibrous tissues change into a mixture of COL1 and type II collagen (COL2) and finally form hyaline cartilaginous tissues consisting of COL2. In order to elucidate the changes that occur in the matrix during cartilage repair and the roles of fibroblasts and chondrocytes in this process, we generated a minimal cartilage defect model that could be spontaneously repaired. Defects of 0.3?mm were created on the patellofemoral articular cartilage of rats using an Er:YAG laser and were observed histologically, ultrastructurally and histochemically. At week 2 after this operation, fibroblastic cells were found to be surrounded by COL1 throughout the area of the defect. These cells became acid phosphatase positive by week 4, both taking in and degrading collagen fibrils. Thereafter, the cells became rounded, with both COL1 and 2 evident in the matrix, and showed immunolocalized matrix metalloproteinase-1 or -9. In the region of the bone marrow, the cells became hypertrophic and were surrounded mainly by COL2 and proteoglycans. By the eighth week, the cartilaginous matrix was found to contain abundant COL2, in which collagen fibrils of various diameters were arranged irregularly. These morphological changes suggested that the fibroblastic cells both produce and resolve the matrix and undertake remodeling to become chondrocytes by converting from a COL1- into a COL2-dominant matrix. This process eventually forms new articular cartilage, but this is not completely identical to normal articular cartilage at the ultrastructural level.     

Development and characteristics of servomotor for use under high temperature and radiation flux conditions

Recently, robots have been required to inspect the insides of nuclear reactors under high temperature and radiation flux conditions. In a FBR (fast breeder reactor), the viewing system of the robot is particularly important because the reactor vessel of the FBR is filled with opaque liquid sodium. To drive this robot, servomotors must meet special requirements. At temperatures above 220°C, the integrity of organic materials cannot be maintained for long periods. In addition, the air-gap length of the motor varies, because metals expand at high temperatures. Thus, the characteristics of induction motors with an air-gap length of 0.2–0.4 mm may vary. Furthermore, the rotor may come into contact with the stator. In this paper, a newly developed permanent magnet motor which can withstand high temperatures and radiation is presented, and the characteristics of the rotor at high temperatures are discussed. Coils for winding ceramic magnetic wires are installed in the stator and Sm₂Co₁₇ permanent magnets are embedded in the rotor yoke. This motor is suitable for use at up to 400°C due to the use of inorganic materials in it. In addition, the permanent magnet motor can incorporate a long air-gap length, which has little effect on the characteristics of the motor. The test results show that the motor has excellent characteristics at high temperature. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(4): 52–65, 1997