Detection of norovirus RNA in bivalve molluscs by using bacteria-culture-employed method (A3T method)

Norovirus (NV) RNA has rarely been detected in foods despite the use of highly sensitive methods such as RT-PCR and real-time RT-PCR. In the modified method (A3T method) reported previously, a bacterial culture process was introduced into the standard protocol for NV detection to remove some inhibitor(s) present in food ingredients. To confirm the efficiency of the A3T method and to examine NV contamination in bivalve molluscs, we tried to detect NV RNA in bivalve molluscs on the market and in oyster samples associated with foodborne outbreaks by using the standard method and the A3T method. NV RNAs were detected in 20 samples (18.0%) of 111 bivalve molluscs, including oysters, on the market by use of the A3T method, while only one sample (0.9%) was positive according to the standard method. NV RNA was also detected in 10 of 35 oyster samples related to foodborne outbreaks by the A3T method. Those results show that the A3T method is suitable for the detection of NV in bivalve molluscs in general laboratories.     

Intermittent administration of brain-derived neurotrophic factor (BDNF) ameliorates glucose metabolism and prevents pancreatic exhaustion in diabetic mice

We previously demonstrated that repetitive administration of brain-derived neurotrophic factor (BDNF) ameliorates glucose metabolism and energy expenditure in obese diabetic db/db mice. However, we have not evaluated in detail the effect of single or intermittent BDNF administration on glucose metabolism in a diabetic animal model. The objectives of this study were to examine the dose-response effect and dosing interval of BDNF administration in db/db mice and to evaluate the effect of intermittent BDNF administration on pancreatic function in db/db mice. We evaluated the dose-response effect of BDNF by single administration in db/db mice. First, single administration of BDNF greater than 70 mg/kg significantly reduced blood glucose concentration one day after administered, and the BDNF effect was maintained for 6 d. Next, the effects of BDNF administered twice a week at 4, 10, 25, and 62.5 mg/kg on blood glucose concentration, and the effects of BDNF administered once a week at 10, 20, 30, 50, and 70 mg/kg on blood glucose concentration were examined in db/db mice. In the intermittent treatment studies, BDNF dose-dependently ameliorated glucose metabolism by not only the twice-a-week administration but also the once-a-week administration. Lastly, because BDNF reduces the food intake of obese hyperphagic diabetic mice, the effects of BDNF administered once or twice a week on the blood glucose concentration and plasma and pancreatic insulin concentrations in db/db mice were compared with those of the vehicle under pair-fed conditions. Under pair-fed conditions, the intermittent administration of BDNF (25 mg/kg, twice a week, or 50 mg/kg, once a week) significantly reduced the blood glucose concentration and increased the plasma and pancreatic insulin concentrations compared with those in the pair-fed vehicle-treated db/db mice. This indicates that the prolonged hypoglycemic effect of BDNF is not simply due to the reduction of food intake. In conclusion, we demonstrated that the intermittent administration of BDNF ameliorates glucose metabolism and prevents pancreatic exhaustion in obese diabetic mice. These findings indicate that BDNF may have potential as a unique hypoglycemic agent for the treatment of diabetes at a fundamental level with good patient compliance.     

Characterization of E- and Z-ajoene obtained from different varieties of garlics

Synthesised E- and Z-ajoene were used to determine their amounts in food oils containing various fresh garlics. The best yield of E-ajoene (172.0 μg/g of garlic) and Z-ajoene (476.0 μg/g of garlic) was obtained from freshly prepared Japanese garlic with rice oil which was heated at 80 °C. Determination of E- and Z-ajoene from soybean oil containing 15% Japanese garlic samples prepared at 80 °C for 0.5 h gave the amount of E-ajoene (170.0 μg/g of garlic) and Z-ajoene (127.0 μg/g of garlic). After 9-month storage, 54.0% E- and 11.0% Z-ajoene remained in Japanese garlic with rice oil. Ajoene (0.1 mM) in ethyl acetate was incubated under UV-light (253.7 nm) for 3 days, 81.7% E- and 56.9% Z-ajoene remained. 4.3% and 0.5% E- and Z-ajoene remained when ajoene (0.1 mM in ethyl acetate) was incubated at 100 °C.     

Evaluation of both image resolution and contrast-to-noise ratio in scanning electron microscopy

The contrast-to-gradient (CG) resolution has been defined as a weighted harmonic mean of the local resolution, i.e. the length defining the object's local fine structure at each pixel position. The newly defined resolution Res is defined as 2 sigma/ sqrt 2, where 2 sigma is a sharpness factor of the image pattern obtained by the conversion 2 sigma = ARCG + B using default constants A and B. In the present study, we have extended the algorithm to change the constants from default values to calibrated ones using standard images that are same in both pattern and contrast-to-noise ratio (CNR) as the original SEM image to be evaluated. The calibrated image resolution with a weak noise dependency is evaluated with the CNR as a given parameter.     

Characterization of compressive deformation behavior of multi-layer porous composite materials for articular tissue engineering

Regeneration of articular layered tissues consisting of cartilage and cancellous bone has been a critical issue in orthopedics. Tissue engineering technology for such large-scale damaged layered tissue may be developed by using layered scaffold with stem cells. In this study, therefore, a novel multi-layer scaffold consisting of a porous poly (?-caprolactone) (PCL) layer for cartilage regeneration and a porous composite layer of poly (L-lactic acid) (PLLA) and hydroxyapatite (HAp) for bone regeneration was developed. The microstructure of the scaffold was characterized by a field emission scanning electron microscope (FE-SEM). Compression tests were also performed to understand the stress-strain behavior. FE-SEM observation clearly showed that an interlayer exists between the PCL and the composite layers. The compressive stress-strain relation is characterized by a stepwise behavior including the first and the second steps. The first modulus corresponding to the first step is mainly related to the deformation of the PCL layer; on the other hand, the second modulus is related to both solidified PCL layer and the composite layer and increases with increase of HAp content of the composite layer. It is also found that the classical mechanics theory and three-dimensional finite element model can predict the first modulus reasonably well.     

A phenolic antioxidant from the Pacific oyster (Crassostrea gigas) inhibits oxidation of cultured human hepatocytes mediated by diphenyl-1-pyrenylphosphine

3,5-Dihydroxy-4-methoxybenzyl alcohol (DHMBA), an antioxidant isolated from the Pacific oyster (Crassostrea gigas), was studied in a cell-based fluorometric antioxidant assay using human hepatocyte-derived cells (C3A) and diphenyl-1-pyrenylphosphine (DPPP) as a fluorescent probe. In comparison with two hydrophilic antioxidants, DHMBA showed the stronger inhibition of DPPP-mediated fluorescence than chlorogenic acid and l-ascorbic acid: at a concentration of 320 μM of DPPP, the inhibition was 26.4 ± 2.6%, 11.1 ± 1.2%, and 0 ± 2.0% for DHMBA, chlorogenic acid, and l-ascorbic acid, respectively (mean ± SD, n = 4). Their relative oxygen radical absorbance capacities (ORAC) were dissociated with their cell-based antioxidant activities: 1.47 ± 0.40, 4.57 ± 0.30, and 0.53 ± 0.13 μmol TE/μmol for DHMBA, chlorogenic acid, and l-ascorbic acid, respectively (mean ± SD, n = 4). The amphiphilicity of DHMBA was better than chlorogenic acid and l-ascorbic acid might underlie this dissociation. Since the C3A cells are human hepatoma-derived cells, DHMBA might be useful in the prevention and treatment of liver diseases by involving an oxidation process.     

Progress in ECRF antenna development for JT-60SA

Structural, mechanical and optical design work on antennas/launchers for the electron cyclotron range of frequency heating and current drive system in JT-60 Super Advanced (JT-60SA) have been advanced based on a linear motion antenna concept. A CAD model of the launcher was built with realistic component sizes. A mock-up of the steering structure consisting of two different bellows sections for poloidal and toroidal beam scanning was fabricated to test movement of the bellows. The poloidal (?40° to +20°) and toroidal (?15° to +15°) injection angle ranges required in JT-60SA were shown to be realized by this steering structure and mirrors.