Production of scFv-Fc fusion protein using genetically manipulated quails

The use of transgenic avian species as a transgenic bioreactor for the production of recombinant proteins has been proposed. In recent years, although various procedures for generating transgenic chickens have been reported, the expression of a useful protein at a commercially feasible level has rarely been attained. In this study, we injected a concentrated retroviral vector into quail embryos to generate genetically manipulated quails that produce recombinant proteins. We found that transgene expression in the whole body at a high level was observed for viral injection into the heart of the developing embryos after a 48-h incubation. For the practical production of a useful protein, a retroviral vector encoding an anti-prion scFv-Fc gene under the control of the beta-actin promoter was injected into quail embryos. The quails that hatched stably produced scFv-Fc at a high level in their serum and egg white. The production of scFv-Fc was maintained throughout the breeding period. scFv-Fc purified from the egg white retained the antigen-binding activity. This system exhibited the potential of transgenic quails for the commercial production of recombinant proteins.     

Transmittance analysis of three-dimensional photonic crystals by the effective medium theory

A simple method for calculating the transmittance of three-dimensional photonic crystals is proposed. The crystals are divided into multilayer thin films, and each film is divided into rectangles with a minute width to calculate the effective permittivity of the film by the effective medium theory. Transmittance of the multilayer thin films is calculated with the matrix method. As the number of atomic layers increases, remarkable stop bands appear. When the refractive index of photonic atoms increases, the stop band shifts to a lower frequency, the band widens, and the number of bands increases. Polarization and incident angle dependences are also analyzed. The limit of application for this calculation method is also discussed.     

Synthesis of Carbon Nanotubes on Fly Ashes by Chemical Vapor Deposition Processing

Fly ashes are the waste product following the combustion of coal. Disposal of fly ashes is a serious environmental problem; therefore, finding a new utilization of fly ashes is highly demanded. Carbon nano-structures have been widely studied as key materials in a wide range of applications, including sensing, saturable absorber, and so on, because of its optical and electromagnetic absorption property. Adding the property of carbon nanotubes (CNTs) to fly ashes expands applications of fly ashes. In this paper, we present the fabrication of multi-walled carbon nanotubes (MWCNTs) on fly ashes by thermal chemical vapor deposition (CVD) process, which result in simple, low-cost, large-amount production of MWCNTs. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Effect of base stocks on the automobile engine bearing

The government has required that engine oil viscosity be lowered and that highly refined base stocks be used in engine oils, with the aim of promoting low fuel consumption and developing long-life oils.To improve the reliability of automobile plain bearings by means of engine oils, we have developed a bearing test apparatus that uses a half-metal. Oil can be supplied through the oil supply port in the same way as in actual engines. In this apparatus, variable loads can be applied to the opposite side of the oil supply hole of the bearing by hydraulic pressure that is synchronized with the rotational speed of the shaft. The influence of the base stocks used for engine oils on the contact between the rotating shaft and the bearing metal, and on the bearing rotating torque generated by rotation of the shaft, were investigated.We found that the contact ratio and the bearing rotating torque varied with different types of base stock compositions, even if the base stocks had the same viscometric properties. Therefore, it is necessary to develop countermeasures to avoid adverse effects when lowering engine oil viscosity and using highly refined base stocks.     

Co-occurrence of mycotoxins in corn samples from the Northern region of Paraná State,Brazil

Natural mycoflora and co-occurrence of fumonisins and aflatoxins were evaluated in 300 freshly-harvested corn samples (2003 and 2004 crops) collected at two points of the production chain in the Northern region of Paraná State, Brazil. In the 2003 crop, fumonisins were detected in 100% of samples and the mean levels were 2.54 μg/g in the reception and 3.12 μg/g in the pre-drying samples. On the other hand, in the 2004 crop fumonisins were detected in 98.9% and 95% of the reception and pre-drying samples, respectively. The mean levels were 1.31 μg/g in the reception, and 1.36 μg/g in the pre-drying samples. Aflatoxins were not detected in 92% of the samples analysed. The maximum probable daily intake (PDI_M) estimated for the Brazilian population (0.95 μg/kg body weight/day) is below the tolerable daily intake of 2.0 μg/kg body weight/day for fumonisin B₁.     

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.     

Thyroid hormones and seasonal reproductive neuroendocrine interactions

Many animals that breed seasonally measure the day length (photoperiod) and use these measurements as predictive information to prepare themselves for annual breeding. For several decades, thyroid hormones have been known to be involved in this biological process; however, their precise roles remain unknown. Recent molecular analyses have revealed that local thyroid hormone activation in the hypothalamus plays a critical role in the regulation of the neuroendocrine axis involved in seasonal reproduction in both birds and mammals. Furthermore, functional genomics analyses have revealed a novel function of the hormone thyrotropin. This hormone plays a key role in signaling day-length changes to the brain and thus triggers seasonal breeding. This review aims to summarize the currently available knowledge on the interactions between elements of the thyroid hormone axis and the neuroendocrine system involved in seasonal reproduction.     

Development of a reliable in vitro maturation system for zebrafish oocytes

In zebrafish oocytes, it has been reported that a 60 or 75% Leibovitz L-15 medium or simple balanced saline solution containing 17alpha, 20beta-dihydroxy-4-pregnen-3-one (DHP) is effective for nuclear maturation. However, most of the oocytes that matured under these conditions were not fertilized and did not hatch. Thus, these in vitro maturation methods could not support the cytoplasmic maturation of zebrafish oocytes. Therefore, we tried to develop a reliable in vitro maturation method for zebrafish oocytes, which supports their ability to be fertilized and to develop till hatching. When zebrafish oocytes at stage III were cultured in 50-100% Leibovitz L-15 medium supplemented with DHP, the highest rates of cleavage (24%) and hatching (12%) were obtained from oocytes matured in 90% Leibovitz L-15 medium. When we examined the suitable pH (7.5-9.5) of the 90% medium, higher rates of cleavage (45%) and hatching (33%) were obtained in oocytes matured at pH 9.0 than at pH 7.5, 8.5, or 9.5 (cleavage rate, 16-29%; hatching rate, 8-21%). In oocytes matured in 90% Leibovitz L-15 medium at pH 9.0, high rates of cleavage (70%) and hatching (63%) were obtained when oocytes were cultured for 270 min with 0.5 mg/ml BSA. Thus, 90% Leibovitz L-15 medium at pH 9.0 containing 0.5 mg/ml BSA was effective for normal maturation of zebrafish oocytes. This method will become a powerful tool for understanding the mechanism of in vitro maturation in zebrafish oocytes and for the practical use of immature oocytes.     

Oxygen vacancies and pseudo Jahn-Teller destabilization in cesium-doped hexagonal tungsten bronzes

Structural and compositional changes of Cs-doped hexagonal tungsten bronzes (HTB) with respect to variations in oxygen deficiency and alkali content have been investigated in detail through x-ray diffraction Rietveld analysis, x-ray photoelectron spectroscopy, and Raman spectroscopy. Cs-HTB crystallized in a reductive atmosphere is evidenced to generally contain plenty of oxygen defects, and a general formula, Cs_xWO_3−y (0.20 ≤ x ≤ 0.32, 0 < y ≤ 0.46), is proposed. Lattice parameters of Cs-HTB are observed to vary according to the relation, c (Å) = −3.436a (Å) + 33.062. The coordinated modification of W–O octahedral dimensions suggests the origin of the structural change with increasing x and y to be a destabilization of the pseudo Jahn-Teller distortion due to donated electrons. The dimensional change of lattice due to electrons emitted from oxygen defects is appraised only 1/18 as that due to electrons from doped alkali ions, suggesting that most electrons from oxygen defects should be localized in Cs-HTB.