Background/Aims: Salicylate and chlorpromazine exert differential effects on the chemokine release from mast cells. Since these drugs are amphiphilic and preferentially partitioned into the lipid bilayers of the plasma membranes, they would induce some morphological changes in mast cells and thus affect the process of exocytosis. Methods: Employing the standard patch-clamp whole-cell recording technique, we examined the effects of salicylate and chlorpromazine on the membrane capacitance (Cm) during exocytosis in rat peritoneal mast cells. Using confocal imaging of a water-soluble fluorescent dye, lucifer yellow, we also examined their effects on plasma membrane deformation of the cells. Results: Salicylate dramatically accelerated the GTP-γ-S-induced increase in the Cm immediately after its application, whereas chlorpromazine significantly suppressed the increase. Treatment with salicylate increased the trapping of the dye on the cell surface, while treatment with chlorpromazine completely washed it out, indicating that both drugs induced membrane surface deformation in mast cells. Conclusion: This study demonstrated for the first time that membrane amphipaths, such as salicylate and chlorpromazine, may oppositely modulate the process of exocytosis in mast cells, as detected by the changes in the Cm. The plasma membrane deformation induced by the drugs was thought to be responsible for their differential effects.

This study experimentally investigated the instability of flow impingement in a cerebral aneurysm, which was speculated to promote the degradation of aneurysmal wall. A patient-specific, full-scale and elastic-wall replica of cerebral artery was fabricated from transparent silicone rubber. The geometry of the aneurysm corresponded to that found at 9 days before rupture. The flow in a replica was analysed by quantitative flow visualization (stereoscopic particle image velocimetry) in a three-dimensional, high-resolution and time-resolved manner. The mid-systolic and late-diastolic flows with a Reynolds number of 450 and 230 were compared. The temporal and spatial variations of near-wall velocity at flow impingement delineated its inherent instability at a low Reynolds number. Wall shear stress (WSS) at that site exhibited a combination of temporal fluctuation and spatial divergence. The frequency range of fluctuation was found to exceed significantly that of the heart rate. The high-frequency-fluctuating WSS appeared only during mid-systole and disappeared during late diastole. These results suggested that the flow impingement induced a transition from a laminar regime. This study demonstrated that the hydrodynamic instability of shear layer could not be neglected even at a low Reynolds number. No assumption was found to justify treating the aneurysmal haemodynamics as a fully viscous laminar flow.

defect is an alternative method, especially when the atrial septum is thickened and resistant to pull-through BAS. Such conditions can be anticipated in infants aged >4-6 weeks or in those with left-sided obstructive lesions such as hypoplastic left heart syndrome (HLHS). 2-5 In addition, all the catheters that could be used for pull-through BAS in Japan required a sheath of 6Fr or larger until recently, which may increase access-related complications in small infants. Therefore, in Japan, static BAS has also been used as an alternative to pull-through BAS to reduce vascular injury in patients with low body weight.Although static BAS cannot be replaced by surgical Balloon atrial septostomy (BAS) is an essential catheterization procedure for some congenital heart lesions that require interatrial communication, such as to increase cardiac output in right-sided obstructive lesions, to enhance mixing in patients with transposition of the great arteries (TGA), and to relieve left atrial hypertension in left-sided obstructive lesions.Pull-through BAS, in which the inflated balloon catheter is forcefully pulled through the atrial septum to tear open the atrial septum, is the conventional and standard BAS method. 1 Static BAS (or static balloon atrial septal dilation) using a dilation balloon to enlarge the atrial septal

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Further development of medical devices for children is required in Japan, but the development of such devices is delayed compared to that of medical devices for adults. Herein, we investigated policies for advancing the development of pediatric medical devices in Japan and the United States. Considering the achievements of each policy, we proposed a strategy to promote further development of pediatric medical devices in Japan. We investigated policies for supporting the development of pediatric medical devices and approved cases in Japan and the United States by searching contents of websites of regulatory bodies and other related administrations, and scientific papers. We found the main six policies in Japan and nine main policies in the United States for the development of pediatric medical devices. In the United States, various measures have initiated mainly in the 2000s, while in Japan, the main measures have been in place since 2013. Similarities were found in both countries, such as subsidies for application fees and research and development expenses, exemption of requirements for regulatory approval, and priority review and consultation by the regulatory body. Our study revealed that there are similarities in initiatives by both countries. To promote further development of pediatric medical devices in the future, improvements to expediting the review process to approval by the regulatory body, global development, and implementation of alternative measures to ensure the efficacy and safety of the device instead of large-scale clinical trials should be anticipated through cooperation among industry, government, and academia.