肥大型心筋症から拡張相肥大型心筋症への移行の予測 : イソプロテレノール 負荷心エコー図法の有用性

Thesis (Ph. D. in Medical Sciences)--University of Tsukuba, (B), no. 1336, 1997.11.30Offprint. Originally published in: Journal of the American College of Cardiology, v. 25, no. 3, pp. 687-692, 1995Joint authors: Keiji Iida ... et alIncludes supplementary treatise

Rigidity Matching between Cells and the Extracellular Matrix Leads to the Stabilization of Cardiac Conduction

Biomechanical dynamic interactions between cells and the extracellular environment dynamically regulate physiological tissue behavior in living organisms, such as that seen in tissue maintenance and remodeling. In this study, the substrate-induced modulation of synchronized beating in cultured cardiomyocyte tissue was systematically characterized on elasticity-tunable substrates to elucidate the effect of biomechanical coupling. We found that myocardial conduction is significantly promoted when the rigidity of the cell culture environment matches that of the cardiac cells (4 kiloPascals). The stability of spontaneous target wave activity and calcium transient alternans in high frequency-paced tissue were both enhanced when the cell substrate and cell tissue showed the same rigidity. By adapting a simple theoretical model, we reproduced the experimental trend on the rigidity matching for the synchronized excitation. We conclude that rigidity matching in cell-to-substrate interactions critically improves cardiomyocyte-tissue synchronization, suggesting that mechanical coupling plays an essential role in the dynamic activity of the beating heart

Exploration of the role of environmental chemical (arsenic) in the development of diabetes and the related metabolic disorders for South Asian Countries

科学研究費助成事業 研究成果報告書：基盤研究(B)2015-2017課題番号 : 15H0529

Galaxy Structures and External Perturbations in Gravitational Lenses

In modeling strong gravitational lens systems, one often adopts simple models, such as singular isothermal elliptical density plus lowest-order external perturbation. However, such simple models may mislead us if the real mass distribution is more complicated than that in the assumed models. In particular, assumptions on mass models are crucial in studying flux ratio anomalies that have been suggested as evidence for a cold dark-matter substructure. We reinvestigated four quadruple lens systems using power-law Fourier models, which have advantages of clear physical meanings and the applicability of a linear method, as well as a simple singular isothermal elliptical density model. We also investigated the effect of external perturbations, including a singular isothermal sphere, lowest-order expansion, and next-order expansion. We have found that the $\cos3\theta$ terms of the primary galaxy and/or of external perturbation significantly reduce the \chi^2 in PG 1115+080 and B1422+231. In particular, we could reproduce the flux ratios of B1422+231 with next-order external perturbation assuming 5% flux uncertainties, suggesting that external perturbation cannot be described by a simple singular isothermal sphere approximation. On the other hand, we could not fit B0712+472 and B2045+265 very well even with our models, although the \chi^2 were reduced compared with the case of using simple models. Our results clearly demonstrate that both the primary lens galaxy and the external perturbation are often more complicated than we usually assume.Comment: 9 pages, 1 figure, to appear in PASJ, Vol. 56, No.

Case Report Bilateral Endoscopic Medial Maxillectomy for Bilateral Inverted Papilloma

Inverted papilloma (IP) is a benign tumor of the nasal cavity and paranasal sinuses that is unilateral in most cases. Bilateral IP, involving both sides of the nasal cavity and sinuses, is extremely rare. This paper describes a large IP that filled in both sides of the nasal cavity and sinuses, mimicking association with malignancy. The tumor was successfully treated by bilateral endoscopic medial maxillectomy (EMM). The patient is without evidence of the disease 24 months after surgery. If preoperative diagnosis does not confirm the association with malignancy in IP, endoscopic sinus surgery (ESS) should be selected, and ESS, including EMM, is a good first choice of the treatment for IP

Effects of ketamine on nicorandil induced ATP-sensitive potassium channel activity in cell line derived from rat aortic smooth muscle

Purpose : Nicorandil opens adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system and is being increasingly used for the treatment of angina pectoris. In the present study, we tested whether intravenous anesthetic agent ketamine affected nicorandil-induced native vascular KATP channel activation. Methods : We used excised inside-out patch clamp configurations to investigate the direct effects of ketamine racemate and S-(+)-ketamine on the activities of KATP channels in cultured rat aortic smooth muscle cells. Furthermore, we also investigated whether intracellular MgADP could modulate ketamine inhibition. Results : Nicorandil significantly activated KATP channel activity, whereas this channel activity was completely blocked by glibenclamide, a specific KATP channel blocker. Ketamine racemate inhibited the nicorandil induced KATP channel activity (IC50=34 1M, n=14), but S-(+)-ketamine was less potent than ketamine racemate in blocking nicorandil induced KATP channel activities (IC50=226 7M, n=10). Application of MgADP to the intracellular side of the channel was able to decrease the inhibitory potency of ketamine racemate on nicorandil induced KATP channel activities. Conclusions : Our results indicate that ketamine inhibits nicorandil induced KATP channel activities in a dose dependent and stereoselective manner. Furthermore, increase of intracellularMgADP attenuates the inhibitory potency of ketamine racemate

First Observation of Superlattice Reflections in the Hidden Order at 105 K of Spin–Orbit Coupled Iridium Oxide Ca5Ir3O12

We report the inelastic X-ray scattering (IXS) experimental results of iridium oxide Ca5Ir3O12 with a strong spin–orbit interaction, showing the hidden order at 105 K where no superlattice reflections were observed so far. We measured the IXS spectra of Ca5Ir3O12 along Γ–A, Γ–M, Γ–K–M, M–L, and K–H directions in the Brillouin zone of a hexagonal lattice down to 20 K. The obtained phonon spectra show almost no change on cooling; there are no soft phonon modes. However, the superlattice reflections specified by wavevector q=(1/3,1/3,1/3) are observed below 105 K. For the order parameter in the hidden order, the characteristic on intensity for observed superlattice reflections can lead to the irreducible representation A2 order parameter in the point group 31m. Furthermore, the theoretical study indicates that the hidden order at 105 K comes from an electric toroidal dipole or higher-order multipole ordering

Role of neurosteroid allopregnanolone on age-related differences in exercise-induced hypoalgesia in rats

The beneficial effects of physical activity for pain are denominated exercise-induced hypoalgesia (EIH). Here, we examined the age-related change and potential role of the neurosteroid allopregnanolone (ALLO) on EIH in rats. Adult and aged rats were randomly divided into one of three groups; non-exercise control, Low-exercise, and High-exercise. The animals in the Low- and High-exercise groups were subjected to a 10-minute treadmill workout at 40% and 80% maximum oxygen intake intensity, respectively. In the Low-exercise groups, a significant EIH response was observed in aged but not in adult rats. The pre-treatment with ALLO synthesis inhibitor finasteride, but not opioid-receptor antagonist naloxone, inhibited the Low-exercise induced EIH response in aged rats. Furthermore, the Low-exercise increased brain ALLO levels in aged animals compared with controls, which was correlated with the mechanical pain sensitivity. On the other hand, High-exercise could induce EIH response in both adult and aged animals, but it was more effective in adult rats. The pre-treatment with naloxone, but not finasteride, reduced the EIH observed after High-exercise in both adult and aged rats. Our findings demonstrated that effective EIH can be achieved even by mild-intensity exercise in aged animals via an increase of the brain ALLO levels

Resveratrol-loaded nanoemulsion prevents cognitive decline after abdominal surgery in aged rats

The maladaptive response of aged microglia to surgery and consequent neuroinflammation plays a key pathogenic role in postoperative cognitive dysfunction (POCD). Here, we assessed the preventive effect of resveratrol (RESV) for POCD in aged rats. The emulsified form of RESV (e-RESV) was selected to improve its oral and brain bioavailability. Animals were assigned to one of four groups: e-RESV (80 mg/kg) versus vehicle treatment by abdominal surgery versus isoflurane anesthesia alone (n = 8 in each group). The dose-dependent effects of e-RESV were also assessed in dose range of 0e60 mg/kg. Either vehicle or e-RESV was administered intragastrically 24 h before surgery. Seven days after procedure, cognitive function was evaluated using a novel object recognition test, followed by measurement of hippocampal pro-inflammatory cytokine levels. Our results showed that pre-treatment with e-RESV attenuated the surgery-induced cognitive impairment and related hippocampal neuroinflammation at 40 mg/kg or higher doses. Additionally, the ex-vivo experiments revealed that the preemptive e-RESV regimen reduced the hippocampal microglial immune reactivity to lipopolysaccharide. Furthermore, e-RESV induced neuroprotective benefits were inhibited by the concomitant administration of sirtinol, a specific SIRT1 inhibitor. Our findings imply the preventive potential of e-RESV for POCD via the SIRT1 signaling pathway

Atomic Bomb Fallout and “Black rain” at Manose District (Hirama-cho) Located Northeast of Nagasaki City

Plutonium atomic bomb (A-bomb) was exploded at 503 meters height above Nagasaki City on August 9, 1945. Many studies on radioactive contamination, radiation dose, effect to people and so on have been conducted until now. Local fallout from the A-bomb mainly spread a lot in the east direction centering on Nishiyama area located about 4 km east of the hypocenter. Like the Hiroshima A-bomb, black rain accompanied by radioactive materials fell shortly after the explosion, but relationship between local fallout fall zone and black rain fall area has not been sufficiently elucidated, which has enhanced the concerns on radiation exposure to the A-bomb survivor. Concerning the black rain due to the Nagasaki A-bomb, it has been said that black rain did not fall across a wide area in a comprehensive way, except for the heavily contaminated Nishiyama area, but fell at various areas with conditions of light rain and/or soaking after the explosion. Among many villages or towns, especially in the Manose District where is a small intermountain village about 7.5 km northeast of the hypocenter, it had always been heard and known that the residents living there encountered black rain and experienced hair loss. In this district, the hair loss of inhabitants occurred actually with high probability, but its reason has not been elucidated well. Therefore, in order to reevaluate the local fallout level in the Manose District by the A-bomb, residual long-lived radionuclides 137Cs and Pu isotopes were measured for soil samples collected at the Manose District including the surrounding areas in July, 2011. As a result, accumulated levels of 137Cs and 239,240Pu in the Manose District were not so high, each being nearly background (BG) level. The dispersion of local fallout Pu from the A-bomb was reconfirmed by 240Pu/239Pu atomic ratios measured in soil samples at the same time, and was found to be primarily limited in the east direction, especially around the Nishiyama area. Those results were consistent with results obtained so far. Further researches are needed for understanding scientifically the cause of the high incidence rate of hair loss in this district.This research was supported by JSPS KAKENHI Grants Numbers 23406002 (April 2011-March 2014) and 26257501 (April 2014-March 2018)