Immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the Japanese black bear, Ursus thibetanus japonicus, during pregnancy

The Japanese black bear, Ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. The objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the Japanese black bear. Ovaries and placentae from 15 wild Japanese black bears, which had been killed legally by hunters and were thought to be pregnant, were used in an immunocytochemical study to localize the cholesterol side chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), 17alpha-hydroxylase cytochrome P450 (P450c17) and aromatase cytochrome P450 (P450arom) by the avidin-biotin-peroxidase complex method using polyclonal antisera raised in mammals against P450scc, 3betaHSD, P450c17 and P450arom. P450scc and 3betaHSD were localized in all luteal cells throughout pregnancy. P450c17 was present in a few luteal cells, especially in the outer area of the corpus luteum throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. Cells positively immunostained for P450c17 were significantly smaller than negatively immunostained cells (P < 0.01). P450arom was present sporadically in a few luteal cells throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. The size of cells positively immunostained for P450arom was not significantly different from that of negatively immunostained cells. The whole placenta was negatively immunostained for P450scc, 3betaHSD and P450c17, but P450arom was present in the syncytiotrophoblasts and endothelial cells of maternal blood vessels. These results indicate that, in the Japanese black bear, corpora lutea are a source of progesterone which may play an important role in the maintenance of delayed implantation and fetal development during pregnancy. Corpora lutea have a minimum capability to synthesize androgen in small luteal cells and oestrogen in normal-sized luteal cells during pregnancy, and placentae have the ability to synthesize oestrogen during late pregnancy.     

Schizosaccharomyces pombe gmd3(+)/alg11(+) is a functional homologue of Saccharomyces cerevisiae ALG11 which is involved in N-linked oligosaccharide synthesis

The oligosaccharide of glycoproteins in the fission yeast Schizosaccharomyces pombe is unique in containing galactose. We isolated four mutants that had reduced amounts of galactose residues on their cell surface glycoproteins by fluorescence-activated cell sorter. The isolated four recessive mutants, gmd1 to gmd4, showed a defect in glycosylation of acid phosphatase, a cell surface glycoprotein. In gmd3 mutant cells, the amounts of both mannose and galactose residues were decreased on the cell surface galactomannoproteins, suggesting an underglycosylation of galactomannoproteins. The gmd3(+) gene encodes a protein that has significant similarity with Saccharomyces cerevisiae Alg11p and is likely to be involved in N-linked core oligosaccharide synthesis. ALG11 suppressed the gmd3 mutation, indicating that gmd3(+) gene is a functional homologue of the ALG11 gene. We therefore designated gmd3(+) as alg11(+).     

Crack growth characteristics of carbon nanotube-based polymer composites subjected to cyclic loading

This paper presents the characterization of crack growth in carbon nanotube (CNT)-based polymer composites under fatigue loading. Fatigue crack growth tests were performed on single-edge cracked plate specimens of CNT/polycarbonate composites at room temperature and liquid nitrogen temperature (77 K). An elastic–plastic finite element analysis was also conducted to determine the J-integral range. The crack growth rate data were expressed in terms of the J-integral range, and the effect of nanotube addition on the fatigue crack growth behavior was examined. In addition, possible mechanisms of the crack growth in the nanocomposites are discussed based on microscopic observations of the specimen fracture surfaces.     

Autonomic nervous system dysfunction in elderly hypertensive patients with abnormal diurnal blood pressure variation: relation to silent cerebrovascular disease

To investigate the relationships among diurnal blood pressure (BP) variations and autonomic nervous system dysfunction, we assessed heart rate variability (HRV) using power spectral analysis of the 24-hour RR interval in 51 asymptomatic elderly hypertensive patients with various patterns of nocturnal BP fall. The extreme-dippers with marked nocturnal BP fall (n=16) had lower asleep low-frequency power (LF)/high-frequency power (HF) ratios (a relative index of sympathetic nervous system activity), while the nondippers without nocturnal BP fall (n=18) had lower awake LF/HF ratios and asleep/awake ratio for HF (an index of parasympathetic nervous activity), when compared with dippers with appropriate nocturnal BP fall (n=17). The incidence of multiple lacunar infarction detected by brain magnetic resonance imaging was 56% in the extreme-dippers and 38% in the nondippers, and both were markedly higher than that (6.3%) in the dippers (both P<.01). There was no significant relationship between the BP level and any HRV parameter for either the daytime or nighttime period. The asleep/awake ratio for systolic BP was significantly correlated with the asleep/awake ratio for HF (r= -.363, P<.01) and with the asleep/awake ratio for the LF/HF ratio (r=.540, P<.001), regardless of whether multiple lacunar infarction was present. In conclusion, the autonomic nervous system activity is not related to high BP level per se, rather its diurnal variation is more important as a determinant of the diurnal BP patterns, regardless of the presence or absence of cerebrovascular disease.     

Osteogenic activity of human periosteal sheets cultured on salmon collagen-coated ePTFE meshes

Our animal implantation studies have demonstrated that, after osteogenic processing, cultured human periosteal sheets form osteoid tissue ectopically without the aid of conventional scaffolding materials. To improve the osteogenic activity of these periosteal sheets, we have tested the effects of including a scaffold made of salmon collagen-coated ePTFE mesh. Periosteal sheets were produced with minimal manipulation without enzymatic digestion. Outgrown cells penetrated into the coated mesh fiber networks to form complex multicellular layers and increased expression of alkaline phosphatase activity in response to the osteoinduction. In vitro mineralization was notably enhanced in the original tissue segment regions, but numerous micro-mineral deposits were also formed on the coated-fiber networks. When implanted subcutaneously into nude mice, periosteal sheets efficiently form osteoid around the mineral deposits. These findings suggest that the intricate three-dimensional mesh composed of collagen-coated fibers substantially augmented the osteogenic activity of human periosteal sheets both in vitro and in vivo.     

An autonomous distributed control method based on tie‐set graph theory in future grid

In future power grids where electricity flows bidirectionally, the essential problem is to maximize the total efficiency of distributed energy resources. In complicated and large‐scale systems such as modern power distribution networks, maximizing the efficiency of the entire system as a whole is extremely difficult. To solve the global optimization problem of such a complex network, this paper proposes an efficient distributed control method for future grid on the basis of tie‐set graph theory, where a tie‐set is a set of all the edges in a loop of a graph. On the basis of tie‐set graph theory, global optimization of an entire network can be realized as a result of local optimization in μ‐dimensional liner vector space, where μ is the nullity of the underlying graph of a power network. Although each tie‐set has its limited local information, an entire network is gradually optimized in an orderly manner because of the theoretical basis of a tie‐set graph. Simulation results of several thousand‐node networks demonstrate balanced allocation of dispersed energy resources and thus effectiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.     

Direct simulation of flowing colloidal dispersions by smoothed profile method

We developed a simulation scheme to predict the dynamic behavior of colloidal dispersion called “smoothed profile (SP) method”. SP method provides a coupling scheme between continuum fluid dynamics and rigid-body dynamics through smoothed profile of colloidal particles. Moreover, SP method can incorporate multi-component fluids, such systems as charged colloids in electrolyte solutions. Numerical results which assess hydrodynamic interactions of colloidal dispersions are presented to validate SP method. Application of SP method is not restricted to a Newtonian solvent, but any constitutive model can be handled. Henceforth, it can be suitable to treat colloidal dispersions in complex fluids where solvent-mediated interaction dominate dynamical behaviors of colloids.