Durable Ventricular Assist Device for Bridge to Transplantation

A durable ventricular assist device (VAD) is a key mechanical circulatory support to safely bridge a heart transplant candidate to transplantation over a long waiting period. Recent UNOS policy change has a great impact on the role of continuous-flow VAD as a bridging device. The rest of the majority of countries still rely on a cf-VAD as a safe and effective support device. A sole durable VAD for bridge to transplantation in pediatric patients is Berlin Heart EXCOR, for which there is a growing demand through the improvement of a long-term result. In this chapter, I will overview the history and the present status of durable VAD for bridge to transplantation in both adult and pediatric patients

Augmentation of natural killer activity by neuraminidase treatment of lymphocytes from tumor-bearing mice.

Spleen cells from tumor-bearing mice showed decreased natural killer (NK) activity and decreased binding to target cells with progression of the tumor. Treatment of spleen cells from tumor-bearing mice with vibrio cholerae neuraminidase (VCN) increased the cytotoxicity to a level twice or more as high as that of untreated cells, but the same treatment of spleen cells from normal mice had no or little effect. On the other hand, neither in spleen cells from tumor-bearing mice nor in those from normal mice, the VCN treatment had no effect on their binding to M-HeLa cells. The suppression of NK activity by preincubation with serum from tumor-bearing mice or prostaglandin E2 was completely abolished by VCN treatment. The above results indicate that VCN treatment of lymphocytes might augment NK activity by an antagonistic effect against an immune suppressive factor.</p

Analysis of boron neutron capture reaction sensitivity using Monte Carlo simulation and proposal of a new dosimetry index in boron neutron capture therapy

Boron neutron capture therapy is a cellular-scale heavy-particle therapy. The factor determining the biological effects in the boron neutron capture reaction (BNCR) is the value of αboron ⁠, which is the alpha component in the Linear Quadratic (LQ) model. Recently, the factor determining the value of αboron has been revealed to correspond to the structural features of the tumor tissue. However, the relationship and mechanism have yet to be thoroughly studied. In this study, we simulated BNCR in tissues using the Monte Carlo simulation technique and examined the factors that determine the value of αboron ⁠. According to this simulation, the nuclear-cytoplasmic (N/C) ratio, nuclear diameter and heterogeneity of the distribution of boron in the tissue have been suggested to determine the value of αboron ⁠. Moreover, we proposed Biological Effectivity (BE) as a new dosimetry index based on the surviving fraction (SF), extending the concept of absolute biological effectiveness (ABE) in a previous report

Changing Pattern in the Comparative Advantage of Shrimp Culture in Asia and the Competitiveness in the Japanese Markets

Promoting shrimp culture industry is one of the effective ways to earn foreign currencies and reduce rural poverty for developing countries. However, there is a question if rising wage rates might be a constraint for further development. Thailand, for example, has established a firm position in the industry, but its export of frozen shrimp has been decreasing and newly emerging countries such as Vietnam are following its path. This paper tries to answer this question by applying the analysis based on the revealed comparative advantage (RCA). We compared the RCA index for major exporters of frozen shrimp, and found that the trend of RCA of Thailand has declined since 1990, while that of Indonesia has been stable and that of Vietnam has been outstanding for the same period. This observation is consistent with the hypothesis that the wage rate is a key deterministic factor of the comparative advantage. What is the competitiveness of shrimp exported from major countries in the Japanese markets? Indeed, Thailand is losing its market share for frozen shrimp, but is expanding the export of high value processed shrimp. Vietnam realizes relatively high prices in spite of the low cost of production and its quality control is also gaining high reputation. Therefore, wage rate is one of the important factors shaping the changes in comparative advantage and competitiveness of shrimp culture, but the strategy of shrimp firms toward high quality and safety products is important too