Na?ve-like conversion enhances the difference in innate in vitro differentiation capacity between rabbit ES cells and iPS cells

Quality evaluation of pluripotent stem cells using appropriate animal models needs to be improved for human regenerative medicine. Previously, we demonstrated that although the in vitro neural differentiating capacity of rabbit induced pluripotent stem cells (iPSCs) can be mitigated by improving their baseline level of pluripotency, i.e., by converting them into the so-called “naïve-like” state, the effect after such conversion of rabbit embryonic stem cells (ESCs) remains to be elucidated. Here we found that naïve-like conversion enhanced the differences in innate in vitro differentiation capacity between ESCs and iPSCs. Naïve-like rabbit ESCs exhibited several features indicating pluripotency, including the capacity for teratoma formation. They differentiated into mature oligodendrocytes much more effectively (3.3–7.2 times) than naïve-like iPSCs. This suggests an inherent variation in differentiation potential in vitro among PSC lines. When naïve-like ESCs were injected into preimplantation rabbit embryos, although they contributed efficiently to forming the inner cell mass of blastocysts, no chimeric pups were obtained. Thus, in vitro neural differentiation following naïve-like conversion is a promising option for determining the quality of PSCs without the need to demonstrate chimeric contribution. These results provide an opportunity to evaluate which pluripotent stem cells or treatments are best suited for therapeutic use.     

Antioxidant constituents in distillation residue of Awamori spirits

Constituents in a distillation residue of Awamori (millet spirits) and their antioxidant activity are investigated in this study. The supernatant of the distillation residue obtained by centrifugation was partitioned with n-hexane, chloroform, ethyl acetate, and n-butanol against water to afford the corresponding solubles. Among them, n-hexane and chloroform solubles showed higher antioxidant potency than l-ascorbic acid by the bleomycin-Fe method. In chloroform solubles, seven cyclic dipeptides were identified along with ethyl 2-pyrrolidione-5-carboxylate, tyrosol, and ethyl p-hydoroxyphenyllactate. Antioxidant activity of ethyl p-hydoroxyphenyllactate was 4.2 times that of l-ascorbic acid, whereas cyclic dipeptides showed activity 0.89-1.29 times as strong as that of l-ascorbic acid. On the other hand, scavenging effect of cyclic dipeptides against O(2)(-.) and OH(.) by using electron spin resonance was also investigated. In the results, cyclo(l-Ile-l-Pro) showed significantly strong inhibitory effect against OH(.) (95.4% at 2.5 x 10-3 M) and cyclo(l-Phe-l-Pro), cyclo(l-Pro-l-Val), and cyclo(l-Leu-l-Pro) inhibited OH(.) 64.9, 54.1, and 51.0%, respectively, whereas alpha-tocopherol showed 37.7% inhibition, though only a few cyclic dipeptides weakly inhibited O(2)(-.).     

Development of an enzyme-linked immunosorbent assay to detect an immunomodulatory alpha-D-glucan-protein complex, MPG-1, in basidiomycete Tricholoma matsutake and related processed foods

We previously isolated a novel immunomodulatory alpha-(1,4)(1,6)(1,2)- d-glucan-protein complex (MPG-1) from mycelia of Tricholoma matsutake in basidiomycetes. In the present study, we raised a polyclonal antibody by immunizing rabbits with MPG-1 and constructed a sandwich enzyme-linked immunosorbent assay (ELISA) system to examine the distribution of MPG-1 among edible mushrooms and related processed foods. The system detected MPG-1 quantitatively at concentrations of more than 10 ng/mL, with a coefficient of variation of less than 10% by intra-assay and interassay precision. Analysis with the system of chemically modified MPG-1 suggested that the sugar moiety was mainly involved in the detection. The system detected MPG-1 in the extracts of the fruiting bodies of T. matsutake but not in those of 34 other basidiomycete species. Moreover, a significant amount of MPG-1 was detected in the extracts of their cultured mycelia. The antigenic structure of MPG-1 was relatively stable in terms of pH and temperature. MPG-1 was detected in processed foods supplemented with T. matsutake. These results suggest that MPG-1 is distributed predominantly in T. matsutake species and that the ELISA system can detect it in processed foods supplemented with T. matsutake.     

Estimation of gillnet selectivity curve by maximum likelihood method

ABSTRACT: A maximum likelihood method of estimating gillnet selectivity when data are obtained by gillnet fleets consisting of several nets of differing mesh size is presented in this paper. The SELECT model is expanded by application of the relative length (i.e. the ratio of fish length to mesh size) to obtain a master curve of gillnet selectivity. Four kinds of functional model, normal, lognormal, skew-normal and bi-normal are fitted to the data. In addition, two cases in which the relative fishing intensity is either estimated or fixed by catch effort are compared. The bi-normal model has the lower model deviance regardless of whether the relative fishing intensity is estimated or not. The estimation of relative fishing intensity by catch effort is also examined in which the estimates of the parameter of the SELECT model are compared with the catch effort as determined by the number of nets of each mesh size used. For the bi-normal model these quantities compare well. Thus, it is concluded that this method gives reliable estimates even if data for each mesh size is obtained with different catch efforts.     

日本沿海捕鳗笼的网目选择性

1995~2000年在东京湾进行的套网法实验,结果表明:网目尺寸为21·0、18·1、15·5、13·6、11·6mm的笼网目选择率在星康吉鳗全长035·50cm、l>32·50cm、l>27·50cm、l>26·50cm、l>24·00cm时,全长选择率几乎接近于1·00,50%选择全长分别为29·80、26·80、23·00、22·00、20·00cm;选择域为3·80、4·30、3·50、3·00、3·00cm。依据AIC理论,套网和实验网的网目接近时,套网的影响显著;Single curve model所得到的主选择性曲线可更好地反映网目选择性。50%选择相对体周长MGc1·11,选择域为0·52。01·60,选择率趋向于1·00。     

Assessment of criteria for improvement in Theileria orientalis sergenti infection tolerance

We examined the relationships between calf productivity, anemia and Theileria orientalis sergenti infection from records of 109 Japanese shorthorn calves during a grazing period and we quantified the relative importance of the T. orientalis sergenti infection‐resistance criteria used. A decrease in average parasitemia (AvePara) and an increase in average packed cell volume (AvePCV) would cause a decrease in the number of drug treatments. An increase in AvePCV would decrease the number of drug treatments more efficiently than a decrease in AvePara. An increase in AvePCV would cause an increase in dairy gain, while a decrease in AvePara would cause a decrease in dairy gain. Therefore, an improvement in the capacity to control anemia development would improve T. orientalis sergenti infection resistance more efficiently than an improvement in the capacity to control parasitemia development.