Plasma Profiles of Glucose, Insulin and Lipids in the Male WBN/Kob-Lepr(fa) Rat, a New Model of Type 2 Diabetes with Obesity

Plasma profiles of glucose, insulin and lipids were examined in the male WBN/Kob-Lepr(fa) (fa/fa) rat, a new model of type 2 diabetes (T2D), in comparison with age-matched original male WBN/Kob (lean) rats. The fa/fa rats developed hypertriglycemia, obesity and hyperglycemia from 5, 7, and 9 weeks of age, respectively. Plasma insulin levels in fa/fa rats were significantly higher than those in lean rats at 5 weeks of age, but after 11 weeks of age gradually declined to the levels in lean rats. HOMA-IR, a measure of insulin resistance status, showed that fa/fa rats had insulin resistance. The fa/fa rat has the potential to become an important animal model of T2D with obesity.     

Effects of soil scraping on the reclamation of tsunami-damaged paddy soil

We investigated the possibility of tsunami-damaged paddy soil remediation in Japan using a scraping method. We collected undisturbed soil blocks to maintain the soil structure from paddy damaged by salt from the tsunami. Scraping treatments to remove the top 2 cm of the soil surface were conducted once, twice, and thrice after drying naturally in a greenhouse environment, as well as a noscraping control. Electrical conductivity (EC) of the soil dramatically decreased to < 1.36 dS m^?1 in the residual soils after scraping. The EC values of the residual soils were significantly lower after being scraped twice or thrice compared with a single scraping. Similarly, the mean NaCl removal rates were significantly higher with two (91%) or three scrapings (97.2%) compared with a single scraping (73.3%). The growth of rice plants was almost normal in the residual soils based on a visual score (approximately 3 on average) using a standard evaluation system at 4 weeks after transplantation. There were no significant differences in the grain yields from the residual soils with different scraping frequencies, and the EC values of all the residual soils were < 1.36 dS m^?1. This study clearly indicates that there were reductions in the EC and good plant growth performance in the residual soils after scraping, and there was also a high rate of NaCl removal. Therefore, scraping may be a useful method for the remediation of salt-damaged paddy soils when irrigation or culvert systems are affected severely by tsunamis and earthquakes.     

PCB 118 and Aryl Hydrocarbon Receptor Immunoassays for Screening Dioxins in Retail Fish

The efficacy of a combination of two enzyme-linked immunosorbent assay (ELISA) kits was examined for screening the toxic equivalent (TEQ) concentrations of dioxins in retail fish. The coplanar PCB-EIA system, which is a competitive immunoassay specific for polychlorinated biphenyl (PCB) 118, was tested as a screening method for mono- ortho PCBs. The Ah immunoassay (Ah-I), which is an ELISA-based aryl hydrocarbon receptor binding assay, was analyzed for its screening ability for non- ortho PCBs, polychlorinated dibenzo- p-dioxins (PCDDs), and dibenzofurans (PCDFs). Dilution and recovery tests using purified fish extracts revealed no major interference of the matrix in the PCB-EIA and suggested that the matrix effect was minimized in the Ah-I. Finally, the results for the fish samples ( n = 20) showed a strong correlation between this method and high-resolution gas chromatography coupled to high-resolution mass spectrometry for the determination of the TEQ concentrations of mono- ortho PCBs ( r = 0.99) and non- ortho PCBs and PCDD/Fs ( r = 0.97). These data indicate that our method is suitable for screening retail fish to determine the TEQ concentrations of dioxins.     

Relationship of European persimmon (Diospyros kaki Thunb.) cultivars to Asian cultivars, characterized using AFLPs

Sixty one persimmon (Diospyros kaki Thunb.) selections, including 17 Italian, 11 Spanish, 13 Japanese, six Korean, five Chinese, one Israeli, and eight of unknown origin, were evaluated for genetic differences by AFLP analysis. Relationships among cultivars were evaluated by UPGMA clustering, Neighbor Joining, and MultiDimensional Scaling. While similarities among groups were generally less than 0.60, both UPGMA and Neighbor Joining separated European and Asian cultivars. Spanish and Italian cultivars were not separated by any of the analyses, suggesting that they share a common gene pool, while Japanese, Chinese and Korean cultivars formed distinct clusters. Diversity within groups was greater than diversity between groups. Most cultivars were quite polymorphic (only 0.60–0.80 similarity between cultivars). In addition, the presence of several Japanese cultivars in the European group and a group of European cultivars nested between Chinese and Korean groups suggest that similar, but different progenitors were used in the development of the present European cultivars. ‘Kaki Tipo’ selections from different sources were clearly different by AFLP analysis, indicating that they are separate cultivars.     

Evaluation of genetic diversity of bread wheat landraces from Pakistan by AFLP and implications for a future collection strategy

We used amplified-fragment-length polymorphism (AFLP) markers to evaluate genetic variation in a set of bread wheat (Triticum aestivum L.) landraces and improved materials. Landraces collected from different geographic and agro-ecological zones in Pakistan in 1987, 1989 and 1991 were separated into two groups based on their geographic origins: northern (Himalaya) and south-western (Balochistan) Pakistan. Six AFLP primer combinations detected 453 AFLP markers in the 43 landrace accessions and four high-yield varieties (HYVs). Of these, 225 (49.67%) were rare (shared with < 5% of all accessions). Among these rare alleles, 23 (10.22%) were common in the Himalaya (shared with > 10% of accessions collected there) but were not found in Balochistan. We conclude that there is a higher probability of collecting rare alleles at overall, but which are in contrast locally common ones in the Himalayan region. Gene diversity was 0.17 in the Himalayan group and 0.15 in the Balochistan group. Considerable genetic variability was found in both groups. Accessions from different agro-ecological zones were indistinguishable by cluster analysis, indicating intensive seed trading within the country. Cluster analysis indicated that the landraces and the HYVs are genetically distinct; suggesting that genetic erosion of wheat landraces has been unlikely taken in place. This study provides an example of how analysis of existing materials and data, can serve as a basis for future collection planning and conservation policies.     

Secretion of inhibin in male Japanese quail (Coturnix japonica) from one week of age to sexual maturity

The objective of this study was to investigate the changes in secretion of inhibin and cellular localization of the inhibin alpha and inhibin/activin (beta(A) and beta(B)) subunits in male Japanese quail from 1 to 7 weeks after hatching. The post-hatch profile of plasma luteinizing hormone (LH), immunoreactive (ir) inhibin and testosterone were measured by radioimmunoassay. Testes were immunostained by the avidin-biotin-peroxidase complex method (ABC) using polyclonal antisera raised against inhibin alpha, inhibin/activin beta(A) and inhibin/activin beta(B) from one week of age to sexual maturity. Testicular weight increased gradually until 4 weeks and abruptly increased from 5 weeks of age onwards. The plasma concentrations of LH and ir-inhibin increased significantly at 5 weeks of age, and the plasma concentration of testosterone increased significantly at 6 weeks of age. Pituitary contents of LH showed a steady increase until 6 weeks of age and then abruptly increased at 7 weeks of age. Coincident to the increase in plasma testosterone, the testicular contents of testosterone significantly increased from 5 weeks through sexual maturity. Immunohistochemically, localization of the inhibin/activin alpha, beta(A) and beta(B) subunits was found in the Sertoli and Leydig cells at all ages of development from one week of age to sexual maturity. These results suggest that Sertoli and Leydig cells are the major source of inhibin secretion during development in male Japanese quail.     

Secretion of inhibin in female Japanese quails (Coturnix japonica) from hatch to sexual maturity

To clarify the cellular source and secretory pattern of inhibin in the Japanese quail during follicular development, the plasma concentrations of immunoreactive (ir) inhibin were measured from 1 to 7 weeks after hatching. Localization of the inhibin/activin alpha, beta A and beta B subunits was investigated by immunohistochemistry. To monitor development of the pituitary and ovarian functions, the plasma luteinizing hormone (LH) and progesterone concentrations were also measured. Ovarian weight increased gradually until 6 weeks of age and then abruptly increased at 7 weeks of age just at the onset of egg production. Plasma concentrations of LH increased significantly at 6 weeks of age. The plasma concentrations of ir-inhibin and progesterone and the pituitary contents of LH also increased significantly at 7 weeks of age. Immunohistochemically, the inhibin/activin alpha, beta A and beta B subunits were localized in the granulosa cells of all follicles during different stages of development from 1 to 7 weeks after hatching. The inhibin alpha, beta A and beta B subunits were also found in the interstitial cells but not theca cells of all follicles. These results demonstrated that the plasma concentrations of ir-inhibin of the female Japanese quails rose with ovarian development. The immunohistochemical results suggested that granulosa and interstitial cells are the major source of ovarian inhibins in female Japanese quails.     

Roles of the hypocretin/orexins in the regulation of sleep and wakefulness

Hypocretin/orexin is produced exclusively in the dorsal and lateral hypothalamus but its projection is widespread within the brain and plays important roles. In this paper, we review the independent discoveries of the hypocretin/orexin peptides, the neuroanatomy of this system, and the link to the sleep disorder narcolepsy that has led to the idea that this system plays a crucial role in the regulation of sleep and wakefulness.