Oblique Surface Dose Calculation in High-Energy X-ray Therapy

During radiation therapy, incident radiation oblique to the skin surface is high and may cause severe skin damage. Understanding the dose of radiation absorbed by the skin is important for predicting skin damage due to radiation. In this study, we used a high-energy (4 MV) X-ray system and an optically stimulated luminescence dosimeter (OSLD) that was developed for personal exposure dosimetry. We determined the dose variation and angular dependence, which are the characteristics of a small OSLD required to derive the calculation formula for the oblique surface dose. The dose variation was determined using the coefficient of variation. The maximum coefficient of variation for 66 small-field OSLDs was 1.71%. The angular dependence, obtained from the dose ratio of the dosimeter in the vertical direction, had a maximum value of 1.37. We derived a new equation in which the oblique surface dose can be calculated within the error range of −7.7-5.1%

Effect of Trans Fatty Acid on Insulin Responsiveness and Fatty Acid Composition of Lipid Species of 3T3-L1 Adipocytes

Trans fatty acids (TFAs) have at least one non-conjugate double bond in trans and TFAs are divided into two groups such as naturally or industry-occurring groups. Recent studies reveal that intake of industrial TFA is linked to increased risk of cardiovascular disease. Moreover, several studies suggest that intake of industrial TFA increases risk of diabetes, although other studies show that intake of industrial TFA is not associated with diabetes. Therefore, we used adipocytes which play important roles in glucose metabolism and development of diabetes, and our previous study showed that persistent exposure to elaidate, a major industrial TFA, impairs insulin-dependent glucose uptake of adipocytes. Since phospholipid acts as a scaffold for molecules of insulin signaling, we analyzed intracellular distribution of elaidate and fatty acid composition of lipid species. Incorporated elaidate is esterified into triglyceride and phospholipid. Moreover, elaidate-esterified phospholipids are distributed in various organelles. Intriguingly, persistent exposure to elaidate reduces the amount of oleate in phospholipid of mitochondria and plasma membrane and disturbs the equilibrium between bent and linear-shaped chain fatty acid. Therefore, disturbed equilibrium of fatty acid composition of phospholipid should be considered to elucidate the mechanism for impaired insulin responsiveness of adipocytes exposed to elaidate

Hip fracture protection by alendronate treatment in postmenopausal women with osteoporosis: a review of the literature

Osteoporosis most commonly affects postmenopausal women, placing them at a significant risk of fractures. In particular, hip fractures are an important cause of mortality and morbidity among postmenopausal women. Anti-resorptive therapies that produce greater decreases in bone turnover markers together with greater increases in bone mineral density (BMD) are associated with greater reductions in fracture risk, especially at sites primarily composed of cortical bone such as the hip. Thus, treatment with potent anti-resorptive drugs like alendronate is a strategy for preventing hip fractures in postmenopausal women with osteoporosis. The purpose of this paper is to discuss the efficacy of alendronate against hip fractures and the mechanism for this anti-fracture efficacy in postmenopausal women with osteoporosis. A meta-analysis of randomized controlled trials has shown that alendronate reduces the risk of hip fractures by 55% in postmenopausal women with osteoporosis. According to the analyses of the Fracture Intervention Trial, each 1 standard deviation reduction in a 1-year change in bone-specific alkaline phosphatase (BSAP) is associated with 39% fewer hip fractures in alendronate-treated postmenopausal women, and those with at least 30% reduction in BSAP have a 74% lower risk of hip fractures relative to those with less than 30%. Alendronate is effective in reducing the risk of hip fractures across a spectrum of ages. The mechanism for this anti-fracture efficacy has been clarified; alendronate strongly suppresses bone turnover and subsequently increases hip BMD, decreases cortical porosity, improves parameters of hip structure geometry (cortical thickness, cross-sectional area, section modulus, and buckling ratio), and produces more uniform mineralization (increases the mean degree of mineralization of bone) in cortical bone. A once-weekly regimen of alendronate administration provides better patient compliance and persistence with the treatment than the once-daily dosing regimen, leading to greater efficacy against hip fractures. Thus, the efficacy of alendronate against hip fractures has been confirmed in postmenopausal women with osteoporosis, especially with a once-weekly dosing regimen