364 results on '"Kazuhiro, Shimizu"'
Search Results
2. Insights into exercise timing to regulate circadian clocks and phenotypes
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Yoshiaki Tanaka, Hiroyuki Sagayama, and Kazuhiro Shimizu
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Exercise timing ,Circadian clocks ,Phenotypes ,Zeitgebers ,Entrainment ,Peripheral clocks ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Summary: Circadian clocks consist of the central clock in the suprachiasmatic nucleus (SCN) and the peripheral clocks in the peripheral tissues and provide endogenous control of physiological functions. Zeitgebers, such as light-dark cycles, exercise, and feeding, entrain the circadian clocks, and proper exposure to such zeitgebers is important for health. Exercise has substantial effects on circadian rhythms. Mouse studies strongly argue that exercise affects the peripheral clock but not the central clock. On the other hand, human studies have shown that exercise affects the melatonin rhythm, which is generally considered to reflect the central clock. From these results, it is plausible that exercise may cause the melatonin rhythm to deviate from the oscillations of the central clock. The regulatory mechanism is unknown. Here, we propose that exercise directly affects the pineal gland, which lies outside the blood-brain barrier, resulting in exercise-induced changes in the melatonin rhythm independent of the central clock.
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- 2023
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3. Effect of balloon pulmonary angioplasty on cardio-ankle vascular index and biventricular remodeling in patients with chronic thromboembolic pulmonary hypertension
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Shuji Sato, Takuro Ito, Tsuyoshi Tabata, Akihiro Ogawa, Atsuhito Saiki, and Kazuhiro Shimizu
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CTEPH ,BPA ,CAVI ,arterial stiffness ,ventricular remodeling ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
BackgroundChronic thromboembolic pulmonary hypertension (CTEPH) is caused by organized pulmonary thrombi, and pulmonary endarterectomy is the only curative treatment. Since balloon pulmonary angioplasty (BPA) has become an established therapeutic option for inoperable CTEPH, prognosis has improved. Recent reports suggest that arterial stiffness evaluated using the cardio-ankle vascular index (CAVI) may play an important role in the cardio-vascular interaction in CTEPH; however, the details remain unclear. This study aimed to clarify the role of CAVI in CTEPH through hemodynamic changes and ventricular remodeling after BPA.Methods and resultsA total of 23 patients with CTEPH who had undergone BPA were enrolled in this study. The mean pulmonary artery pressure (mPAP) and CAVI significantly decreased after BPA [mPAP, 34 (26–45) mmHg to 20 (19–24) mmHg, p
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- 2023
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4. Analysis of effects of acute hypovolemia on arterial stiffness in rabbits monitored with cardio-ankle vascular index
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Yoshinobu Nagasawa, Akira Shimoda, Hiroki Shiratori, Takenori Morishita, Kiyoshi Sakuma, Tatsuo Chiba, Xin Cao, Satoshi Kawakami, Megumi Aimoto, Chikao Miyazaki, Shuji Sato, Mao Takahashi, Kazuhiro Shimizu, Kohji Shirai, and Akira Takahara
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Hypovolemia ,Elasticity ,Arterial stiffness ,Cardio-ankle vascular index ,Autonomic nervous activity ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Although elasticity of the conduit arteries is known to be contribute effective peripheral circulation via Windkessel effects, the relationship between changes in intra-aortic blood volume and conduit artery elasticity remains unknown. Here we assessed the effects of change in intra-aortic blood volume induced by blood removal and subsequent blood transfusion on arterial stiffness and the involvement of autonomic nervous activity using our established rabbit model in the presence or absence of the ganglion blocker hexamethonium (100 mg/kg). Blood removal at a rate of 1 mL/min gradually decreased the blood pressure and blood flow of the common carotid artery but increased a stiffness indicator the cardio-ankle vascular index, which was equally observed in the presence of hexamethonium. These results suggest that arterial stiffness acutely responds to changes in intra-aortic blood volume independent of autonomic nervous system modification.
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- 2022
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5. Variabilities of salivary human herpesvirus 6/7 and cortisol levels during a three-day training camp in judo athletes
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Shinsuke Tamai, Hiroaki Hiraoka, Kazuhiro Shimizu, Keisuke Miyake, Daisuke Hoshi, Kai Aoki, Koki Yanazawa, Takehito Sugasawa, Kazuhiro Takekoshi, and Koichi Watanabe
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fatigue ,assessment ,saliva ,biomarker ,virus ,hormone ,Sports medicine ,RC1200-1245 ,Physiology ,QP1-981 - Abstract
Physical fatigue accompanying athletic training has been a problem for ages. While salivary cortisol has traditionally been used to assess physical stressors, salivary human herpesvirus 6 and/or 7 (HHV-6/7) have recently been presented as novel microbiological markers. Thus, we examined differences in the short-term variabilities of salivary HHV-6/7 and cortisol levels in athletes. We collected saliva samples from 14 healthy male university judo athletes who participated in a three-day training camp pre- and post-training each day to measure salivary HHV-6/7 and cortisol levels. Simultaneously, the plasma superoxide dismutase (SOD) inhibition rates and total mood disturbance (TMD) scores in the Profile of Mood States were measured as indicators of physical and psychological stressors, respectively. The plasma SOD inhibition rates significantly increased post-training, but the TMD scores did not change; thus, the physical stressors were relatively higher than the psychological stressors during the training camp. Salivary HHV-6/7 levels increased post-training with a significant main effect of training, but no changes were observed in the daily levels. Only salivary HHV-7 levels showed a significant training × elapsed day interaction. Salivary cortisol levels showed a significant main effect of training, but its levels decreased post-training. These findings suggest that salivary HHV-6/7 are sensitive markers of physical fatigue more than salivary cortisol.
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- 2022
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6. Changes in blood pressure and arterial stiffness monitored using the cardio–ankle vascular index during hemodialysis
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Shuji Sato, Kazuhiro Shimizu, Mao Takahashi, Motoyuki Masai, Osamu Nagakawa, Junji Uchino, Toshihiro Suzuki, Yuka Sato, Noriko Iwai, and Kohji Shirai
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CAVI ,arterial stiffness ,hemodialysis ,intra-dialytic hypotension ,vascular function ,Physiology ,QP1-981 - Abstract
During hemodialysis (HD), blood pressure (BP) changes are frequently observed. However, the mechanism of BP changes during HD has not been fully clarified. The cardio–ankle vascular index (CAVI) reflects the arterial stiffness of the arterial tree from the origin of the aorta to the ankle independent from BP during measurement. Additionally, CAVI reflects functional stiffness in addition to structural stiffness. We aimed to clarify the role of CAVI in regulating the BP system during HD. We included 10 patients undergoing 4-hour HD (total 57 HD sessions). Changes in the CAVI and various hemodynamic parameters were evaluated during each session. During HD, BP decreased and CAVI significantly increased (CAVI, median [interquartile range]; 9.1 [8.4–9.8] [0 min] to 9.6 [9.2–10.2] [240 min], p < 0.05). Changes in CAVI from 0 min to 240 min were significantly correlated with water removal rate (WRR) (r = −0.42, p = 0.002). Changes in CAVI at each measurement point were negatively correlated with ΔBP (Δsystolic BPeach MP, r = −0.23, p < 0.0001; Δdiastolic BPeach MP, r = −0.12, p = 0.029). Whereas one patient exhibited a simultaneous decrease in BP and CAVI during the initial 60 min of HD. Arterial stiffness monitored with CAVI generally increased during HD. CAVI elevation is associated with decreased WWR and BP. An increase in CAVI during HD may reflect the contraction of smooth muscle cells and play an important role in BP maintenance. Hence, measuring CAVI during HD may distinguish the cause of BP changes.
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- 2023
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7. The association of ACTN3 R577X polymorphism with sports specificity in Japanese elite athletes
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Nobuhiko Akazawa, Nao Ohiwa, Kazuhiro Shimizu, Natsumi Suzuki, Hiroshi Kumagai, Noriyuki Fuku, and Yasuhiro Suzuki
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elite athletes ,actn3 r577x polymorphism ,sports events ,Sports medicine ,RC1200-1245 ,Biology (General) ,QH301-705.5 - Abstract
The α-actinin-3 proteins regulate muscle function and are located in the Z-line of the fast skeletal muscle. A common null polymorphism of R577X in α-actinin-3 gene (ACTN3) results in its complete absence in fast-twitch muscles. The ACTN3 R577X polymorphism is associated with sprint/power performance in athletes. However, little is known about how this polymorphism impacts sports other than sprint/power-oriented sports in Japanese elite athletes. The aim of our study was to examine the association between ACTN3 R577X polymorphism and elite athlete status in various sports categorized as power/sprint, endurance, artistic, martial arts, and ball game sports. The subjects included 906 Japanese elite athletes and 649 Japanese controls. We analysed the genotype frequency of the ACTN3 R577X polymorphism in sprint/power (n = 120), endurance (n = 150), artistic (n = 45), martial arts (n = 94), and ball game (n = 497) sports athletes. A higher number of sprint/power athletes were R allele carriers compared to the controls, and the endurance and artistic athletes (OR = 1.69, 1.83, and 2.36, 95% CI: 1.02–2.79, 1.02–3.31, and 1.08–5.13, respectively). The frequency of RR genotype was higher in sprint/power, martial arts, and ball game sports athletes (OR = 1.61, 1.84, and 1.39, 95% CI: 1.04–2.50, 1.11–2.95, and 1.05–1.83, respectively) compared to control. Furthermore, there is a significant linear trend with increasing R allele according to athletic status (P for trend < 0.05). The ACTN3 R allele is positively associated with sports performance requiring explosive power such as sprint/power, martial arts, and ball game sports categories.
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- 2021
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8. A Case of Idiopathic Orbital Inflammation with Shallow Anterior Chamber and Choroidal Detachment
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Yohei Sato, Natsuko Mano, Hiroko Watanabe, Makiko Miyamoto, Kazuhiro Shimizu, Noriko Mukai, Masashi Mimura, Hidehiro Oku, and Tsunehiko Ikeda
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idiopathic orbital inflammation ,shallow anterior chamber ,choroidal detachment ,Ophthalmology ,RE1-994 - Abstract
We report a case of idiopathic orbital inflammation with a shallow anterior chamber and choroidal detachments. This study involved an 87-year-old female patient who presented at our department after becoming aware of the progression of diplopia. Examination of the patient’s right eye revealed proptosis, as well as conjunctival edema with dilated and tortuous blood vessels. The right-eye anterior chamber was shallow, and fundus examination revealed marked choroidal detachments. Magnetic resonance imaging revealed enlargement of the right-orbit extraocular muscles and a suspected compression of the right-orbit superior and inferior ophthalmic veins, yet no expansion of the cavernous sinus. We diagnosed the patient as having idiopathic orbital inflammation in her right orbit, and subsequently started corticosteroid therapy. One week after initiating treatment, the anterior chamber was found to be nearing a normal depth, and the choroidal detachments were found to have disappeared. Our findings revealed that the inflammatory swelling of the extraocular muscle due to idiopathic orbital inflammation resulted in compression of the right-orbit superior and inferior ophthalmic veins, thus leading to an apparent choroidal circulation disorder that presented with a shallow anterior chamber and marked choroidal detachments.
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- 2020
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9. Spontaneous disappearance and recurrence of impending macular hole: a case report
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Makiko Miyamoto, Kazuhiro Shimizu, Yohei Sato, Bunsei Konose, Natsuko Mano, Hiroko Watanabe, and Tsunehiko Ikeda
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Impending macular hole ,Spontaneous disappearance ,Recurrence ,Optical coherence tomography (OCT) ,Medicine - Abstract
Abstract Background There have been several reports of spontaneous closure and reopening of a macular hole, however, in most of those cases, it was observed in eyes post vitrectomy. Here, we report a case of multiple episodes of spontaneous disappearance and recurrence of impending macular hole (stage 1B macular hole) with no history of previous surgery. Case presentation A 76-year-old Japanese man presented with a primary complaint of reduced visual acuity in his right eye. On initial examination, the visual acuity in his right and left eye was 0.4 and 0.01, respectively. He had previously been diagnosed as having macular degeneration of unknown origin in his left eye. Optical coherence tomography imaging confirmed vitreomacular traction and impending macular hole in his right eye. After a 1-week follow-up period, posterior vitreous detachment was detected, and the impending macular hole appeared to be resolved. Two months later, the impending macular hole had completely disappeared and his visual acuity had improved to 0.9. Six months later, he again noticed decreased vision in his right eye. An examination revealed that his visual acuity had dropped to 0.4, and there was a recurrence of impending macular hole. An optical coherence tomography examination showed no definitive findings of vitreous traction, and, 1 month later, spontaneous disappearance was observed again and his visual acuity improved to 0.7. Conclusions In this case, both the initial onset and the recurrence involved impending macular hole, however, the optical coherence tomography findings differed at each examination. These findings suggest that some causes other than vitreous traction were responsible for both the spontaneous disappearance and recurrence of the impending macular hole in this present case.
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- 2019
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10. The Relationship Between Cardio-Ankle Vascular Index and Left Atrial Phasic Function in Hypertensive Patients With Preserved Ejection Fraction
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Tsuyoshi Tabata, Kazuhiro Shimizu, Yukihiro Morinaga, Naoaki Tanji, Ruiko Yoshida, Masahiro Iwakawa, Hajime Kiyokawa, and Nobuo Takada
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arterial stiffness ,cardio-ankle vascular index ,hypertension ,left atrial phasic function ,speckle-tracking echocardiography ,Medical technology ,R855-855.5 - Abstract
Background: To investigate the relationship between arterial stiffness, reflected by cardio-ankle vascular index (CAVI) value, and left atrial (LA) phasic function in hypertensive patients with preserved left ventricular ejection fraction (LVEF).Methods: We retrospectively studied 165 consecutive patients (mean age, 66.5 ± 11.7 years) diagnosed with hypertension with preserved LVEF who had undergone CAVI measurement and echocardiography on the same day. The latter included speckle-tracking echocardiography to assess LA phasic function (reservoir, conduit, and pump strain) and left ventricular global longitudinal strain (LVGLS).Results: The results of univariate analysis showed CAVI value to be correlated with LA reservoir strain and LA conduit strain (r = −0.387 and −0.448, respectively; both P < 0.0001). The results of multiple linear regression analysis showed CAVI value to be independently related to age (β = 0.241, P = 0.002) and LA conduit strain (β = −0.386, P = 0.021) but not LV mass index, LA volume index, or LV systolic function (including LVGLS).Conclusion: In hypertensive patients with preserved LVEF, increased CAVI value appears to be independently associated with impaired LA phasic function (particularly LA conduit function) before LA and LV remodeling. CAVI determination to assess arterial stiffness may be useful in the early detection of interactions between cardiovascular abnormalities in hypertensive patients.
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- 2021
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11. Physiological role of nitric oxide for regulation of arterial stiffness in anesthetized rabbits
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Tatsuo Chiba, Kiyoshi Sakuma, Tetsuya Komatsu, Xin Cao, Megumi Aimoto, Yoshinobu Nagasawa, Kazuhiro Shimizu, Mao Takahashi, Yuichi Hori, Kohji Shirai, and Akira Takahara
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Therapeutics. Pharmacology ,RM1-950 - Abstract
We assessed effects of acetylcholine and Nω-Nitro-l-arginine methyl ester hydrochloride (l-NAME) on the cardio-ankle vascular index (CAVI), an indicator of arterial stiffness from origin of aorta to tibial artery, in halothane-anesthetized rabbits. Acetylcholine decreased the blood pressure, femoral vascular resistance and CAVI, whereas l-NAME did not affect the CAVI at a hypertensive dose. The acetylcholine-induced decrement of CAVI was completely suppressed by l-NAME. These results suggest that the arterial stiffness in rabbits may be independent from homeostatic production of nitric oxide, however, it can be decreased by large amounts of nitric oxide that are intrinsically produced by exogenously administered acetylcholine. Keywords: Arterial stiffness, Acetylcholine, l-NAME
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- 2019
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12. Experimental study on sparse modeling of a diesel engine air path system.
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Kazuhiro Shimizu, Hayato Nakada, and Kenji Kashima
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- 2017
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13. The role of arterial stiffness in the onset of Takotsubo cardiomyopathy observed with noradrenaline administration and intracranial blood injection in rabbits
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Mao Takahashi, Chikao Miyazaki, Cao Xin, Shuji Sato, Kazuhiro Shimizu, Tatsuo Chiba, Hisayuki Tsukuma, Tetsuya Komatsu, Megumi Aimoto, Yoshinobu Nagasawa, Akira Takahara, and Kohji Shirai
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Cardiology and Cardiovascular Medicine - Published
- 2023
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14. Effect of balloon pulmonary angioplasty on cardio-ankle vascular index and biventricular remodeling in patients with chronic thromboembolic pulmonary hypertension.
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Shuji Sato, Takuro Ito, Tsuyoshi Tabata, Akihiro Ogawa, Atsuhito Saiki, and Kazuhiro Shimizu
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- 2024
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15. A Case of a Newborn with Agenesis of the Corpus Callosum Complicated with Ocular Albinism
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Michiko Miki, Makiko Miyamoto, Tatsuma Mitsutsuji, Hiroko Watanabe, Kazuhiro Shimizu, Junko Matsuo, Masahiro Tonari, Teruyo Kida, Jun Sugasawa, and Tsunehiko Ikeda
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Vici syndrome ,Ocular albinism ,Agenesis of the corpus callosum ,Hypopigmentation ,Ophthalmology ,RE1-994 - Abstract
Purpose: To report a case of ocular albinism found in a newborn infant in whom agenesis of the corpus callosum (ACC) was indicated in utero. Case Report: This study involved a female newborn who was delivered after a gestational period of 41 weeks. The patient was referred to the Obstetrics Department at Takatsuki Hospital, Takatsuki City, Japan, after the indication of ACC by magnetic resonance imaging (MRI) at a nearby clinic during the fetal period. At birth, the baby’s weight was 2,590 g, and ACC and ventricular enlargement were found by cranial sonography and cranial MRI. While initial ophthalmic findings noted partial loss of pigmentation of the iris and hypopigmentation of broad areas of the fundus in both eyes, nystagmus was not observed. The patient’s hair pigment was slightly diluted, and the color of her skin was slightly off-white. At 2 years after birth, obvious mental retardation was observed. With regard to other systemic findings, no apparent heart, kidney, or immune system abnormalities were found. Conclusion: Although the patient in question is presently growing without any major systemic problems, it will be necessary in the future to pay attention to any changes in systemic and ophthalmic findings.
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- 2016
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16. Improvement of Damage Segmentation Based on Pixel-Level Data Balance Using VGG-Unet
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Jiyuan Shi, Ji Dang, Mida Cui, Rongzhi Zuo, Kazuhiro Shimizu, Akira Tsunoda, and Yasuhiro Suzuki
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fully convolutional network ,damage segmentation ,VGG-Unet ,pixel-level data balance ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In this research, 200 corrosion images of steel and 500 crack images of rubber bearing are collected and manually labeled to build the data set. Then the two data sets are respectively adopted to train VGG-Unet models in two methods, aiming to conduct Damage Segmentation by inputting different size of data set. One method is Squashing Segmentation to input squashed images from high resolution directly into VGG-Unet model while Cropping Segmentation uses cropped image with size 224 × 224 as input images. Because the proportion of damage pixels in the data set is different, the results produced by the two data sets are quite different. For large size damage (such as corrosion) segmentation, Cropping Segmentation has a better result while for minor damage (such as crack) segmentation, the result is opposite. The main reason is the gap in the concentration of valid data from the data set. To improve the capability of crack segmentation based on Cropping Segmentation, Background Data Drop Rate (BDDR) is adopted to reduce the quantity of background images to control the proportion of damage pixels from the data set in pixel-level. The ratio of damage pixels from the data set can be decided by different value of BDDR. By testing, the accuracy of Cropping Segmentation becomes relatively higher under BDDR being 0.8.
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- 2021
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17. Whole-Body Cryotherapy Enhances the Expression of Heat Shock Protein 70 and Related Hormones
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Nobuhiko Eda, Kazuhiro Shimizu, Ai Takemura, Emi Narumi, Mariko Nakamura, Masako Hoshikawa, and Michiko Dohi
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General Medicine - Abstract
BACKGROUND: Whole-body cryotherapy (WBC) is used as a conditioning method for athletes. However, the scientific evidence for its effects is still insufficient. OBJECTIVE: To elucidate the effects of transient WBC on the expression of heat shock protein (HSP) 70 and the secretion of related hormones in humans. MATERIALS AND METHODS: The participants in this study were six healthy adult men. WBC was performed for 3 min in a booth at a temperature in the range of -150 to -120°C, and measurements were taken immediately before (Pre), immediately after (Post), and 60 min after WBC (Post60). For measurement of core body temperature (gastrointestinal temperature), participants ingested a capsule-type wireless temperature sensor. The body surface temperature was measured using a noncontact thermometer, and measurements were taken at four sites on the body surface (chest, abdomen, front of the thigh, and front of the lower thigh). Leukocyte count, lactate dehydrogenase, creatine kinase, hemoglobin, hematocrit, adrenaline, noradrenaline, cortisol, adrenocorticotropic hormone (ACTH), erythropoietin, and HSP70 in the collected blood were measured. RESULTS: The results showed a decrease in body surface temperature and an increase in noradrenaline and ACTH immediately after WBC. In addition, the core body temperature decreased 60 min after WBC, accompanied by an increase in HSP70 expression. CONCLUSION: WBC may increase HSP70 expression via noradrenaline and ACTH. The results of this study suggest the usefulness of WBC in triggering protein synthesis and the maintenance of immune function after training.
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- 2022
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18. Cumulative Cigarette Consumption is Associated with Cardio-Ankle Vascular Index (CAVI) Mediated by Abdominal Obesity Assessed by A Body Shape Index (ABSI): A Cross-Sectional Study
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Daiji Nagayama, Jesse C Krakauer, Nir Y Krakauer, Tomonori Sugiura, Yasuhiro Watanabe, Kazuhiro Shimizu, Atsuhito Saiki, Kenji Suzuki, Kentaro Fujishiro, and Kohl Shirai
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Biochemistry (medical) ,Internal Medicine ,Cardiology and Cardiovascular Medicine - Published
- 2023
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19. Cardio-ankle vascular index (CAVI) differentiates pharmacological properties of vasodilators nicardipine and nitroglycerin in anesthetized rabbits
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Tatsuo Chiba, Mari Yamanaka, Sachie Takagi, Kazuhiro Shimizu, Mao Takahashi, Kohji Shirai, and Akira Takahara
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Nitroglycerin ,Nicardipine ,Phenylephrine ,Doxazosin ,Cardio-ankle vascular index (CAVI) ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Cardio-ankle vascular index (CAVI) has been developed for measurement of vascular stiffness from the aorta to tibial artery, which is clinically utilized for assessing the progress of arteriosclerosis. In this study, we established measuring system of the CAVI in rabbits, and assessed whether the index could reflect different pharmacological actions of nitroglycerin and nicardipine on the systemic vasculature. Rabbits were anesthetized with halothane, and the CAVI was calculated from the well-established basic equations with variables obtained from brachial and tibial blood pressure and phonocardiogram. Nicardipine (1, 3 and 10 μg/kg, i.v.) decreased the blood pressure, femoral vascular resistance, and heart-ankle pulse wave velocity (haPWV). Meanwhile, no significant change was detected in the CAVI at the low or middle dose, which reflects the defining feature of the CAVI that is independent of blood pressure. The index increased at the high dose. Nitroglycerin (2, 4 and 8 μg/kg, i.v.) decreased the blood pressure, femoral vascular resistance, and haPWV. Meanwhile, the CAVI was decreased during the nitroglycerin infusion, which may reflect its well-known pharmacological action dilating conduit arteries. These results suggest that the CAVI differentiates the properties of these vasodilators in vivo.
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- 2015
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20. Optical Coherence Tomography in an Infant with Walker-Warburg Syndrome
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Natsuko Mano, Tatsuma Mitsutsuji, Yamato Yoshikawa, Makiko Miyamoto, Hiroko Watanabe, Kazuhiro Shimizu, Michiko Miki, Masashi Mimura, Mari Ueki, and Tsunehiko Ikeda
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Walker-Warburg syndrome ,Optical coherence tomography ,Persistent hyaloid artery ,Congenital glaucoma ,Retinal dysplasia ,Ophthalmology ,RE1-994 - Abstract
Purpose: Walker-Warburg syndrome (WWS) is a type of congenital muscular dystrophy (CMD) characterised by severe brain malformation, lissencephaly, and congenital eye abnormalities. Despite the coexistence of various eye abnormalities, results from optical coherence tomography (OCT) in WWS have not previously been reported. We herein report specific OCT findings in an infant with WWS. Patients and Methods: The patient was a 14-day-old boy delivered by caesarean section at 38 weeks and 4 days of gestation and with a birth weight of 2,543 g. A cranial MRI showed lissencephaly, hydrocephalus, an encephalocele, and cerebellar hypoplasia, consistent with the diagnosis of WWS. Results: A bilateral ocular examination showed no abnormalities of the anterior eye segment. A fundus examination showed a persistent hyaloid artery in the vitreous cavity, a widespread loss of fundus pigmentation, transparent choroidal vessels (some choroidal vessel sections were visible), and the absence of a distinct macular reflex. OCT showed no foveal pit and an indistinct laminar structure of the retina. The infant subsequently developed congenital glaucoma and he then died of respiratory failure at the age of 8 months. Conclusions: WWS is associated with a high incidence of congenital eye abnormalities, and this infant showed findings consistent with WWS. OCT revealed a marked retinal dysplasia.
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- 2015
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21. Effects of Enhanced Intracranial Pressure on Blood Pressure and the Cardio-Ankle Vascular Index in Rabbits
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Tatsuo Chiba, Kazuhiro Shimizu, Tomoyuki Yamamoto, Chikao Miyazaki, Kiyoshi Sakuma, Akira Takahara, Nobuo Sugo, Mao Takahashi, Yoshinobu Nagasawa, Megumi Aimoto, and Kohji Shirai
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Male ,medicine.medical_specialty ,Intracranial Pressure ,medicine.medical_treatment ,Blood Pressure ,030204 cardiovascular system & hematology ,Cisterna magna ,Central venous pressure ,03 medical and health sciences ,chemistry.chemical_compound ,Vascular Stiffness ,0302 clinical medicine ,Internal medicine ,Carotid blood flow ,Internal Medicine ,medicine ,Animals ,Saline ,Intracranial pressure ,business.industry ,musculoskeletal, neural, and ocular physiology ,Biochemistry (medical) ,Cardio-ankle vascular index ,medicine.disease ,Autonomic nervous system ,Blood pressure ,Cardio Ankle Vascular Index ,chemistry ,Cardiology ,Arterial stiffness ,Original Article ,Hexamethonium ,Rabbits ,Ankle ,Cardiology and Cardiovascular Medicine ,business ,030217 neurology & neurosurgery - Abstract
Aim: Stroke is well known to lead to hypertension; nevertheless, the role of vascular function in hypertension remains unclear. In this study, we aimed to clarify the mechanism underlying increased arterial stiffness following stroke. Methods: The cardio-ankle vascular index (CAVI) was measured in five New Zealand White rabbits. Under general anesthesia, intracranial pressure (ICP) was increased by injecting saline (15 mL) into the cisterna magna. ICP was monitored using a catheter inserted into the subarachnoid space via right frontal bone craniotomy. Blood pressure (BP), CAVI, and common carotid flow (CCF) were evaluated, and the responses of these parameters to increased ICP were analyzed. Results: Saline injection into the cisterna magna increased the ICP by over 20 mmHg. Both BP and CAVI increased from 63.2±4.84 to 128.8±14.68 mmHg and from 4.02±0.28 to 4.9±0.53, respectively. Similarly, BP and CCF increased. When hexamethonium was administered before the increase in ICP, the increase in BP (132.2±9.41 mmHg with 10 mg/kg hexamethonium vs. 105.6±11.01 mmHg with 100 mg/kg hexamethonium) and CAVI (5.02±0.64 with 10 mg/kg hexamethonium vs. 4.82±0.42 with 100 mg/kg hexamethonium) were suppressed in a dose-dependent manner. Conclusion: Increased ICP causes an increase in BP and CAVI, suggesting that enhanced stiffness of the muscular arteries contributes to high BP. Blocking the autonomic nervous system with hexamethonium suppresses the increase in BP and CAVI, indicating that these increases are mediated by activation of the autonomic nervous system.
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- 2021
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22. CAVI-Lowering Effect of Pitavastatin May Be Involved in the Prevention of Cardiovascular Disease: Subgroup Analysis of the TOHO-LIP
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Mizuho Kanayama, Yasuhiro Watanabe, Kohji Shirai, Yoh Miyashita, Atsuhito Saiki, Daiji Nagayama, Masao Moroi, Kazuhiro Shimizu, Mao Takahashi, Takashi Yamaguchi, Ichiro Tatsuno, Masahiro Ohira, and Naoko Sato
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Male ,medicine.medical_specialty ,Atorvastatin ,Subgroup analysis ,030204 cardiovascular system & hematology ,Gastroenterology ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Low-density lipoprotein cholesterol ,Pitavastatin ,Adverse effect ,Aged ,Proportional hazards model ,business.industry ,Anticholesteremic Agents ,Incidence (epidemiology) ,Biochemistry (medical) ,Hazard ratio ,Cholesterol, LDL ,Cardio-ankle vascular index ,Middle Aged ,Cardiovascular disease ,Cardio Ankle Vascular Index ,Cardiovascular Diseases ,Quinolines ,Original Article ,Female ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,Cardiology and Cardiovascular Medicine ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Aim: In the TOHO Lipid Intervention Trial Using Pitavastatin (TOHO-LIP), a multicenter randomized controlled trial, pitavastatin significantly reduced cardiovascular (CV) events compared to atorvastatin in patients with hypercholesterolemia. To investigate the mechanism by which pitavastatin preferentially prevents CV events, we investigated the relationship between CV events and cardio-ankle vascular index (CAVI) using the TOHO-LIP database. Methods: For the subgroup analysis, we selected patients from a single center, Toho University Sakura Medical Center. After excluding those who had CV events at baseline or during the first year, 254 patients were enrolled. The primary end point was the same as that of TOHO-LIP, and three-point major cardiac adverse events (3P-MACE) was added as secondary end point. Results: The cumulative 5-year incidence of 3P-MACE (pitavastatin 1.6%, atorvastatin 6.1%, P =0.038) was significantly lower in pitavastatin group (2 mg/day) than in atorvastatin group (10 mg/day). CAVI significantly decreased only in pitavastatin group during the first year (9.50–9.34, P =0.042), while the change in low-density lipoprotein cholesterol (LDL-C) did not differ between the two groups. The change in CAVI during the first year positively correlated with 3P-MACE and tended to be an independent predictor of 3P-MACE in Cox proportional hazards model (hazard ratio, 1.736; P =0.079). The annual change in CAVI throughout the observation period was significantly higher in subjects with CV events compared to those without. Conclusions: In this subgroup analysis, the reduction in CV events tended to be associated with the CAVI-lowering effect of pitavastatin, which was independent of the LDL-C-lowering effect.
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- 2021
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23. Mining Disjunctive Sequential Patterns from News Stream.
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Kazuhiro Shimizu, Isamu Shioya, and Takao Miura
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- 2007
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24. Realtime and Robust Motion Tracking by Matched Filter on CMOS+FPGA Vision System.
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Kazuhiro Shimizu and Shinichi Hirai
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- 2007
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25. Implementing Planar Motion Tracking Algorithms on CMOS+FPGA Vision System.
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Kazuhiro Shimizu and Shinichi Hirai
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- 2006
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26. CMOS+FPGA Vision System for Visual Feedback of Mechanical Systems.
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Kazuhiro Shimizu and Shinichi Hirai
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- 2006
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27. Rapid Rise in Cardio-Ankle Vascular Index as a Predictor of Impending Cardiovascular Events -Smooth Muscle Cell Contraction Hypothesis for Plaque Rupture
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Kazuhiro Shimizu, Mao Takahashi, Shuji Sato, Atsuhito Saiki, Daiji Nagayama, Takashi Hitsumoto, Akira Takahara, and Kohji Shirai
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Endocrinology, Diabetes and Metabolism ,Public Health, Environmental and Occupational Health ,Hematology ,General Medicine ,Arteries ,Plaque, Atherosclerotic ,Vascular Health and Risk Management ,Vascular Stiffness ,Cardio Ankle Vascular Index ,Cardiovascular Diseases ,Humans ,Pharmacology (medical) ,Ankle ,Cardiology and Cardiovascular Medicine - Abstract
Kazuhiro Shimizu,1 Mao Takahashi,1 Shuji Sato,1 Atsuhito Saiki,1 Daiji Nagayama,1,2 Takashi Hitsumoto,3 Akira Takahara,4 Kohji Shirai1,5 1Department of Internal Medicine, Toho University Sakura Medical Center, Sakura, Chiba, Japan; 2Department of Internal Medicine, Nagayama Clinic, Oyama, Tochigi, Japan; 3Hitsumoto Medical Clinic, Shimonoseki, Yamaguchi, Japan; 4Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, Japan; 5Department of Internal Medicine, Seijinkai Mihama Hospital, Chiba, Chiba, JapanCorrespondence: Kazuhiro Shimizu, Department of Internal Medicine, Toho University Sakura Medical Center, 561-4 Shimoshizu, Sakura, Chiba, 285-8741, Japan, Tel +81-43-462-8811, Fax +81-43-462-8820, Email k432@sakura.med.toho-u.ac.jpAbstract: Predictive factors for vascular events have not been established. The vasculature of the atheroma is supplied by penetration of the vasa vasorum through the smooth muscle cell layer from the adventitia. Smooth muscle cell contraction induces compression of the vasa vasorum, resulting in ischemia in intimal atheromatous lesions. Cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. We hypothesized that rapidly increased arterial stiffness evaluated by CAVI may be a predictor of impending cardiovascular events.Keywords: arterial stiffness, stress, plaque rupture, CAVI
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- 2022
28. Cardio-Ankle Vascular Index Reflects the Efficacy of Waon Therapy in Heart Failure Patients
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Takahiro Nakagami, Kazuhiro Shimizu, Keiichi Hirano, Hajime Kiyokawa, Masahiro Iwakawa, Yuki Ikeda, Takashi Akiba, Keiichiro Terayama, Akihiro Ogawa, and Kohji Shirai
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Heart Failure ,Vascular Stiffness ,Cardio Ankle Vascular Index ,Heart Ventricles ,Humans ,General Medicine ,Ankle ,Cardiology and Cardiovascular Medicine - Abstract
Waon therapy is a form of thermal treatment in a dry sauna developed by Tei. Although Waon therapy is reportedly effective for chronic heart failure (CHF) patients, not all patients respond to the therapy. The reason for this ineffectiveness has not been fully clarified. The cardio-ankle vascular index (CAVI) is an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle, and it is thought to reflect some of the afterload of the left ventricle. We investigated the effects of Waon therapy on CAVI and plasma brain natriuretic peptide (BNP) level to clarify the usefulness of CAVI during Waon therapy.CHF patients (n = 21) treated with Waon therapy (2 weeks of 10 sessions) were divided into two groups: responders with an improved BNP level (n = 11) and nonresponders with no improvement in BNP (n = 10). CAVI was measured using Vasela 1500.A significant decrease in CAVI (median and interquartile range) was observed in the responder group (from 10.3 [9.6, 11.6] to 9.6 [8.6, 10.3], P = 0.021), whereas no change was observed in the nonresponder group (from 9.6 [8.6, 10.5] to 9.5 [9.1, 11.2], P = 0.919). The incidence of rehospitalization or cardiac death due to heart failure was significantly higher in patients in whom Waon therapy was ineffective at 12 months of follow-up (log-rank P = 0.001).The effectiveness of Waon therapy in CHF patients may be reflected by the improvement in CAVI.
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- 2022
29. Cardio-Vascular Interaction Evaluated by Speckle-Tracking Echocardiography and Cardio-Ankle Vascular Index in Hypertensive Patients
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Tsuyoshi Tabata, Shuji Sato, Ruiko Ohno, Masahiro Iwakawa, Hajime Kiyokawa, Yukihiro Morinaga, Naoaki Tanji, Toshio Kinoshita, and Kazuhiro Shimizu
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Organic Chemistry ,General Medicine ,Catalysis ,Computer Science Applications ,Inorganic Chemistry ,Cardio Ankle Vascular Index ,Echocardiography ,Hypertension ,arterial stiffness ,cardio-ankle vascular index ,hypertension ,right atrial phasic function ,speckle-tracking echocardiography ,Humans ,Ankle ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Retrospective Studies - Abstract
Hypertension increases arterial stiffness, leading to dysfunction and structural changes in the left atrium (LA) and left ventricle (LV). However, the effects of hypertension on the right atrium (RA) and the right ventricle are still not fully understood. The purpose of this study was to clarify whether there is an interaction not only in the left ventricular system but also in the right ventricular system in hypertensive patients with preserved LV ejection fraction. The current retrospective observational study included patients (n = 858) with some risk of metabolic abnormalities (hypertension, diabetes, and dyslipidemia) who had visited our hospital and undergone echocardiography between 2015 and 2018. Among them, we retrospectively studied 165 consecutive hypertensive patients with preserved LV ejection fraction who had echocardiography performed on the same day as a cardio-ankle vascular index (CAVI) in our hospital. The phasic function of both atria was evaluated by two-dimensional speckle-tracking echocardiography. CAVI was measured using Vasela 1500 (Fukuda Denshi®). In the univariate analysis, CAVI was significantly correlated with LA and RA conduit function (LA conduit function, r = −0.448, p = 0.0001; RA conduit function, r = −0.231, p = 0.003). A multivariate regression analysis revealed that LA and RA conduit function was independently associated with CAVI (LA, t = −5.418, p = 0.0001; RA, t = −2.113, p = 0.036). CAVI showed a possibility that the association between heart and vessels are contained from not only LA phasic function but also RA phasic function in hypertensive patients.
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- 2022
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30. Disjunctive Sequential Patterns on Single Data Sequence and Its Anti-monotonicity.
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Kazuhiro Shimizu and Takao Miura
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- 2005
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31. Analysis of vertical sound image control with parametric loudspeakers.
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Shigeaki Aoki, Kazuhiro Shimizu, and Kouki Itou
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- 2017
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32. Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate Ingestion on Muscle Damage after Eccentric Exercise in Healthy Males: A Pilot Placebo-Controlled Double-Blind Crossover Study
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Yoko Tanabe, Mio Nishimaki, Naoto Fujii, Nobuhiko Akazawa, Kazuhiro Shimizu, and Hideyuki Takahashi
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Male ,0301 basic medicine ,Pharmacology ,Placebo ,Double blind ,Eating ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Isothiocyanates ,Isometric Contraction ,Delayed onset muscle soreness ,Humans ,Medicine ,Ingestion ,Pharmacology (medical) ,Range of Motion, Articular ,Muscle, Skeletal ,Cross-Over Studies ,030109 nutrition & dietetics ,Nutrition and Dietetics ,biology ,Calpain ,business.industry ,Myalgia ,030229 sport sciences ,Crossover study ,Bioactive compound ,body regions ,Torque ,chemistry ,Isothiocyanate ,biology.protein ,medicine.symptom ,business ,Muscle Contraction ,Food Science - Abstract
An animal study demonstrated that 6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC), a major bioactive compound in Japanese pungent spice wasabi, has an action of inhibiting the activation of calpain-1 (a protease). Increases in calpain activity can cause continual strength loss after eccentric exercise. It remains to be determined in humans whether 6-MSITC intake would modulate calpain and/or muscle damage responses after eccentric exercise. We performed a randomized, double-blind, crossover design study wherein eight healthy young males were randomly assigned to ingest 9 mg/day of 6-MSITC or placebo from 1 day before exercise to 4 days after exercise (30 maximal isokinetic eccentric contractions of the elbow flexors using an isokinetic dynamometer). Calpain-1 concentration, inflammatory and muscle damage markers (creatine kinase activity, urinary titin concentration, muscle strength, range of motion, muscle soreness and transverse relaxation time) were assessed. Plasma calpain-1 concentration after eccentric exercise was similar between the placebo- and 6-MSITC-treated conditions. All muscle damage and inflammatory markers were not affected by 6-MSITC relative to those in the placebo-treated condition. Our results suggest that 6-MSITC has no effect on plasma calpain-1 concentration and muscle damage and inflammatory markers measured after eccentric exercise.
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- 2021
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33. Urinary N-terminal fragment of titin: A surrogate marker of serum creatine kinase activity after exercise-induced severe muscle damage
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Hiroyuki Sagayama, Kazuhiro Shimizu, Hideyuki Takahashi, Naoto Fujii, and Yoko Tanabe
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Adult ,Male ,medicine.medical_specialty ,animal structures ,Urinary system ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,Muscle damage ,Upper Extremity ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Delayed onset muscle soreness ,medicine ,Humans ,Connectin ,Orthopedics and Sports Medicine ,Muscle Strength ,Range of Motion, Articular ,Creatine Kinase ,Exercise ,medicine.diagnostic_test ,biology ,Surrogate endpoint ,business.industry ,Magnetic resonance imaging ,Myalgia ,030229 sport sciences ,musculoskeletal system ,Healthy Volunteers ,Endocrinology ,Eccentric exercise ,embryonic structures ,cardiovascular system ,biology.protein ,Serum creatine kinase ,Titin ,medicine.symptom ,business ,tissues ,Biomarkers - Abstract
We aimed to evaluate whether changes in the noninvasively assessed urinary N-terminal fragment of titin (U-titin) concentration may be associated with those of serum creatine kinase (CK) activity, transverse relaxation time (T
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- 2021
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34. Increased Arterial Stiffness in Chronic Thromboembolic Pulmonary Hypertension Was Improved with Riociguat and Balloon Pulmonary Angioplasty: A Case Report
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Mahito Noro, Mao Takahashi, Takuro Ito, Kazuhiro Shimizu, Masakazu Tsubono, Akihiro Ogawa, Shuji Sato, Takeshi Sasaki, and Kohji Shirai
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medicine.medical_specialty ,medicine.medical_treatment ,Case Report ,030204 cardiovascular system & hematology ,Riociguat ,chronic thromboembolic pulmonary hypertension ,ventricular afterload ,03 medical and health sciences ,0302 clinical medicine ,Afterload ,medicine.artery ,Internal medicine ,Angioplasty ,medicine ,Aorta ,business.industry ,cardio-ankle vascular index ,General Medicine ,medicine.disease ,Pulmonary hypertension ,arterial stiffness ,Blood pressure ,Pulmonary artery ,030221 ophthalmology & optometry ,Cardiology ,Arterial stiffness ,business ,medicine.drug - Abstract
Background The role of arterial stiffness in the pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is unclear. The cardio-ankle vascular index (CAVI) is a novel arterial stiffness index reflecting stiffness of the arterial tree from the origin of the aorta to the ankle, independent from blood pressure at the time of measurement. CAVI reflects functional stiffness, due to smooth muscle cell contraction or relaxation, and organic stiffness, due to atherosclerosis. Here, we report the case of a patient with an increased CAVI due to CTEPH and the improvement after riociguat administration and balloon pulmonary angioplasty (BPA). Case presentation A 65-year-old man suffered from dyspnea on exertion, and he was diagnosed with distal CTEPH. The mean pulmonary artery pressure (mPAP) was 51 mmHg, and the initial CAVI was 10.0, which is high for patient's age. In addition to right ventricular dysfunction, left ventricular dysfunction was observed as reduced global longitudinal strain (GLS-LV). After riociguat administration, CAVI decreased to 9.1 and GLS-LV improved from -10.3% to -17.3%, although pulmonary hypertension remained (mPAP 41 mmHg). Subsequently, a total of five BPA sessions were performed. Six months after the final BPA, mPAP decreased to 19 mmHg and GLS-LV improved to 19.3%. The patient was symptom free and his 6-minute walk distance improved from 322 m to 510 m. CAVI markedly decreased to 5.8, which is extremely low for his age. Conclusion These observations suggested that arterial stiffness as measured by CAVI was increased in CTEPH, potentially deteriorating cardiac function because of enhanced afterload. The mechanism of the increase of CAVI in this case of CTEPH was obscure; however, riociguat administration and BPA might improve the pathophysiology of CTEPH partly by decreasing CAVI.
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- 2021
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35. Chronic Thromboembolic Pulmonary Hypertension Due to Popliteal Vein Aneurysm
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Takanori Ikeda, Takuro Ito, Masakazu Tsubono, Kazuhiro Shimizu, and Shuji Sato
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medicine.medical_specialty ,pulmonary embolism ,venous thromboembolism ,Case Report ,030204 cardiovascular system & hematology ,Asymptomatic ,chronic thromboembolic pulmonary hypertension ,popliteal vein aneurysm ,03 medical and health sciences ,0302 clinical medicine ,Aneurysm ,Internal medicine ,Popliteal vein ,medicine.artery ,pulmonary hypertension ,Pulmonary angiography ,Medicine ,cardiovascular diseases ,Thrombus ,business.industry ,General Medicine ,medicine.disease ,Pulmonary hypertension ,Pulmonary embolism ,Pulmonary artery ,cardiovascular system ,030221 ophthalmology & optometry ,Cardiology ,medicine.symptom ,business - Abstract
Background Venous thromboembolism (VTE) may present acutely as pulmonary embolism (PE), and its late complications include chronic thromboembolic pulmonary hypertension (CTEPH). PEs may arise from thrombi originating in a venous aneurysm, in rare cases of the popliteal vein. Case presentation A 77-year-old woman was referred to our hospital due to respiratory distress. Computed tomography revealed pulmonary thrombi and a thrombus in a popliteal vein aneurysm (PVA); PE was diagnosed. After 3 months of anticoagulant therapy (rivaroxaban), her pulmonary hypertension showed little improvement. She underwent perfusion scintigraphy, which showed multiple perfusion defects, and Swan-Ganz catheterization. Mean pulmonary artery pressure was 26 mmHg. Pulmonary angiography revealed organized distal thrombi. Based on these findings, we diagnosed CTEPH due to recurrent formation of thrombi in the PVA. Conclusion Asymptomatic PVA can lead silently to PE and CTEPH. The possibility of asymptomatic recurrent VTE should be considered in patients with pulmonary hypertension and PVA.
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- 2021
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36. Rapid Rise of Cardio-Ankle Vascular Index May Be a Trigger of Cerebro-Cardiovascular Events: Proposal of Smooth Muscle Cell Contraction Theory for Plaque Rupture
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Chikao Miyazaki, Mao Takahashi, Kohji Shirai, Shuji Sato, Akira Takahara, Daiji Nagayama, Atsuhito Saiki, Kazuhiro Shimizu, and Masashi Harada
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medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,030204 cardiovascular system & hematology ,Cerebro ,Muscle, Smooth, Vascular ,03 medical and health sciences ,Vascular Stiffness ,0302 clinical medicine ,Predictive Value of Tests ,Risk Factors ,Internal medicine ,medicine.artery ,medicine ,Humans ,Pharmacology (medical) ,030212 general & internal medicine ,Aorta ,Rupture, Spontaneous ,business.industry ,Public Health, Environmental and Occupational Health ,smooth muscle cell contraction ,Hematology ,General Medicine ,Arteriosclerosis ,Hypothesis ,CAVI ,Atherosclerosis ,Prognosis ,medicine.disease ,Plaque, Atherosclerotic ,Arterial tree ,Vascular Health and Risk Management ,Cerebrovascular Disorders ,arterial stiffness ,medicine.anatomical_structure ,Atheroma ,Cardio Ankle Vascular Index ,Cardiovascular Diseases ,Vasoconstriction ,Vasa vasorum ,cardiovascular system ,Arterial stiffness ,Cardiology ,Ankle ,Cardiology and Cardiovascular Medicine ,business ,Stress, Psychological - Abstract
Kazuhiro Shimizu,1 Mao Takahashi,1 Shuji Sato,1 Atsuhito Saiki,1 Daiji Nagayama,1 Masashi Harada,2 Chikao Miyazaki,2 Akira Takahara,3 Kohji Shirai1 1Department of Internal Medicine, Toho University Sakura Medical Center, Sakura, Chiba, Japan; 2Department of Neurosurgery, Toho University Omori Medical Center, Omori, Tokyo, Japan; 3Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, JapanCorrespondence: Kohji ShiraiDepartment of Internal Medicine, Toho University Sakura Medical Center, 561-4 Shimoshizu, Sakura City, Chiba, 285-8741, JapanTel +81-43-462-8811Fax +81-43-462-8820Email kshirai@kb3.so-net.ne.jpAbstract: Cardiovascular diseases have been recognized as the main cause of death all over the world. Recently, the established cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. Considering the vasculature of the atheroma where vasa vasorum penetrates the smooth muscle cell layer and supplies blood to the intimal atheromatous lesion, a rapid rise of CAVI means “choked” atheroma. Thus, we proposed a “smooth muscle cell contraction” hypothesis of plaque rupture.Keywords: arterial stiffness, atherosclerosis, smooth muscle cell contraction, CAVI
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- 2021
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37. Effect of nicorandil administration on cardiac burden and cardio-ankle vascular index after coronary intervention
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Masayo Kawazoe, Kazuhiro Shimizu, Mao Takahashi, Shuji Sato, Mahito Noro, Takuo Iizuka, Kohji Shirai, and Hiroshi Mikamo
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Male ,medicine.medical_specialty ,Time Factors ,Heart Diseases ,Vasodilator Agents ,medicine.medical_treatment ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Percutaneous coronary intervention ,Angina ,03 medical and health sciences ,Vascular Stiffness ,0302 clinical medicine ,Internal medicine ,Troponin I ,medicine ,Humans ,Angina, Stable ,cardiovascular diseases ,030212 general & internal medicine ,Infusions, Intravenous ,Nicorandil ,Aged ,Cardiac burden ,business.industry ,Hemodynamics ,Middle Aged ,Cardio-ankle vascular index ,medicine.disease ,Brain natriuretic peptide ,surgical procedures, operative ,Treatment Outcome ,medicine.anatomical_structure ,Myocardial injury ,Conventional PCI ,cardiovascular system ,Vascular resistance ,Arterial stiffness ,Cardiology ,Female ,Original Article ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Myocardial injury is a problem associated with percutaneous coronary intervention (PCI). This study aimed to clarify the role of nicorandil administration in preventing myocardial injury. This study included patients with stable angina who underwent PCI from November 2013 to June 2016. Of 58 consecutive patients, the first 20 patients received only saline infusion after PCI (control group); the other 38 patients received a continuous intravenous infusion of nicorandil and saline after PCI (nicorandil group). Troponin I and brain natriuretic peptide (BNP) levels were measured. Vascular parameters, such as blood pressure (BP), cardiac output, cardio-ankle vascular index (CAVI), and estimated systemic vascular resistance (eSVR), were measured. Troponin I of both groups increased 12 h after PCI. Changes in BNP levels between immediately after PCI and 12 h after PCI were significantly higher in the control than in the nicorandil group (10.8 ± 44.2 vs. − 2.6 ± 14.6 pg/ml, p = 0.04). In the nicorandil group, BP, eSVR, and CAVI decreased significantly at 12 h after PCI compared with those immediately after PCI (p r = 0.36, p r = − 0.47, p
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- 2020
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38. Predictive ability of arterial stiffness parameters for renal function decline: a retrospective cohort study comparing cardio-ankle vascular index, pulse wave velocity and cardio-ankle vascular index 0
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Daiji Nagayama, Kentaro Fujishiro, Toru Miyoshi, Shigeo Horinaka, Kenji Suzuki, Kazuhiro Shimizu, Atsuhito Saiki, and Kohji Shirai
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Vascular Stiffness ,Physiology ,Internal Medicine ,Humans ,Ankle Brachial Index ,Blood Pressure ,Ankle ,Pulse Wave Analysis ,Cardiology and Cardiovascular Medicine ,Kidney ,Retrospective Studies - Abstract
The relative usefulness of arterial stiffness parameters on renal function remains controversial. This study aimed to compare the predictive ability of three arterial stiffness parameters at baseline; cardio-ankle vascular index (CAVI), heart-ankle pulse wave velocity (haPWV) and CAVI 0 , a variant of CAVI that theoretically excludes dependence on blood pressure, for renal function decline in Japanese general population.A total of 27 864 Japanese urban residents without renal impairment at baseline who participated in two to eight consecutive (mean 3.5 ± 1.7 times) annual health examinations were studied.During the study period, 6.6% of participants developed renal function decline (estimated glomerular filtration rate60 ml/min per 1.73 m 2 ), all of whom had relatively high values in all arterial stiffness parameters. In receiver-operating characteristic curve analysis, the discriminatory power for renal function decline showed a decreasing trend of CAVI to haPWV to CAVI 0 (C-statistic: 0.740 vs. 0.734 vs. 0.726). The cut-offs were CAVI 8.0, haPWV 7.23 and CAVI 0 11.6. In Cox-proportional hazards analysis for increase of each parameter above cut-off or by 1 standard deviation (SD) adjusted for two models of confounders, only CAVI always contributed significantly to renal function decline. Restricted cubic spline regression analysis suggested that CAVI most accurately reflected the risk of renal function decline.Increase in arterial stiffness parameters, especially CAVI, may represent a major modifiable risk factor for renal function decline in the general population. Further research is needed to examine whether CAVI-lowering interventions contribute to the prevention of chronic kidney disease.
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- 2022
39. Mild hyperbaric oxygen for the early improvement of mood disturbance induced by high-intensity exercise
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Tatsuya Saito, Kazuhiro Shimizu, Ai Takemura, and Nobuhiko Eda
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Adult ,Male ,Hyperbaric Oxygenation ,medicine.medical_specialty ,business.industry ,High intensity ,Physical Therapy, Sports Therapy and Rehabilitation ,medicine.disease_cause ,Profile of mood states ,Crossover study ,Oxygen ,Affect ,Mood disturbances ,Hyperbaric oxygen ,Mood ,Heart Rate ,Internal medicine ,Heart rate ,Cardiology ,Humans ,Medicine ,Orthopedics and Sports Medicine ,business ,Exercise ,Oxidative stress - Abstract
BACKGROUND Excessive training stress can result in decreased performance and deep fatigue due to hormonal changes. There are few available data on recovery methods for mood disturbance, especially fatigue, after high-intensity training. This study, therefore, aimed to examine the effects of mild hyperbaric oxygen at 1.3 atmospheres absolute with 31% oxygen on mood disturbance induced by high-intensity exercises. METHODS Ten healthy adult men participated in and completed 2 trials: the control (CON) trial and the mild hyperbaric oxygen (MHO) trial. In a randomized crossover design, each subject cycled for 60 min at the physical work capacity at 75% of their maximal heart rate and were subsequently exposed to the CON and MHO conditions for 60 min as the recovery period. RESULTS During the 20 to 40 min recovery time points, the average change ratio of heart rates was lower in the MHO trial than in CON (p < 0.05). We observed that the fatigue-inertia, tension-anxiety, and total mood disturbance Profile of Mood States (POMS) scores decreased 60 min post-exercise in the MHO trial, but no differences of these score were observed in the CON trial. There were no differences in oxidative stress, derived-reactive oxygen metabolites, and biological antioxidant potential between both trials. These results suggest that impaired mood states induced by high-intensity exercise can be improved early by MHO without any changes in oxidative stress. This improvement may be associated with decreased heart rate secondary to MHO exposure after the high intensity exercise. CONCLUSIONS We conclude that MHO can improve mood disturbances, especially in the fatigue-inertia and tension-anxiety domains, after high-intensity exercise. This study suggest that MHO is potentially an effective recovery method for mood states after high-intensity training.
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- 2022
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40. A clinical survey of dehydration during winter training in elite fencing athletes
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Nobuhiko EDA, Yasuyuki AZUMA, Ai TAKEMURA, Tatsuya SAITO, Mariko NAKAMURA, Nobuhiko AKAZAWA, Maho YAMAMOTO, Takashi NAITO, Nobukazu KASAI, Kazuhiro SHIMIZU, Yusuke AOKI, and Masako HOSHIKAWA
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Male ,Dehydration ,Tea ,Athletes ,Creatinine ,Sodium ,Potassium ,Humans ,Water ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,Female ,Chlorine - Abstract
Fencing is suggested as one of the most dangerous sporting events in terms of dehydration because of the uniform and gear covering the entire body. We aimed to elucidate the change in hydration status before and after training in elite fencing athletes in winter along with the assessment of sex and fencing style differences.Twenty-seven elite fencing athletes (14 males and 13 females) belonging to the Japanese National Team participated in this clinical survey. Dehydration status before and after winter training was assessed using body mass change, fluid intake, urine osmolarity, urine specific gravity (USG), and sodium, potassium, chlorine, and creatinine levels.More than half of the participants (59.3%) drank water and tea during training. The change rate of body mass (males vs. females, 1.61±0.82% vs. 0.45±0.68%, P0.01; foil vs. epee, 2.25±0.45% vs. 1.16±0.72%, P0.05) and sweating rate (males vs. females, 938±251 g/h vs. 506±92 g/h, P0.01; foil vs. epee, 1136±156 g/h vs. 796±207 g/h, P0.05) during training showed significant differences between sexes and fencing styles. Of all participants, 66.7% were dehydrated (USG≥1.020), and 37.0% were seriously dehydrated (USG≥1.030) before training.Fencing athletes may be susceptible to severe dehydration before training, even in winter. Additionally, males and foil fencers appear to be at a greater risk than females and epee fencers of developing dehydration during exercise.
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- 2021
41. Analysis of effects of acute hypovolemia on arterial stiffness in rabbits monitored with cardio-ankle vascular index
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Yoshinobu Nagasawa, Akira Shimoda, Hiroki Shiratori, Takenori Morishita, Kiyoshi Sakuma, Tatsuo Chiba, Xin Cao, Satoshi Kawakami, Megumi Aimoto, Chikao Miyazaki, Shuji Sato, Mao Takahashi, Kazuhiro Shimizu, Kohji Shirai, and Akira Takahara
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Pharmacology ,Male ,Hypovolemia ,RM1-950 ,Arteries ,Cardio-ankle vascular index ,Arterial stiffness ,Elasticity ,Autonomic nervous activity ,Vascular Stiffness ,Cardio Ankle Vascular Index ,Acute Disease ,cardiovascular system ,Molecular Medicine ,Animals ,Therapeutics. Pharmacology ,Rabbits ,Monitoring, Physiologic - Abstract
Although elasticity of the conduit arteries is known to be contribute effective peripheral circulation via Windkessel effects, the relationship between changes in intra-aortic blood volume and conduit artery elasticity remains unknown. Here we assessed the effects of change in intra-aortic blood volume induced by blood removal and subsequent blood transfusion on arterial stiffness and the involvement of autonomic nervous activity using our established rabbit model in the presence or absence of the ganglion blocker hexamethonium (100 mg/kg). Blood removal at a rate of 1 mL/min gradually decreased the blood pressure and blood flow of the common carotid artery but increased a stiffness indicator the cardio-ankle vascular index, which was equally observed in the presence of hexamethonium. These results suggest that arterial stiffness acutely responds to changes in intra-aortic blood volume independent of autonomic nervous system modification.
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- 2021
42. A Case of Idiopathic Orbital Inflammation with Shallow Anterior Chamber and Choroidal Detachment
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Natsuko Mano, Masashi Mimura, Tsunehiko Ikeda, Hidehiro Oku, Makiko Miyamoto, Kazuhiro Shimizu, Noriko Mukai, Hiroko Watanabe, and Yohei Sato
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medicine.medical_specialty ,genetic structures ,Case Report ,Fundus (eye) ,Extraocular muscles ,01 natural sciences ,03 medical and health sciences ,0302 clinical medicine ,lcsh:Ophthalmology ,Ophthalmology ,medicine ,0101 mathematics ,Diplopia ,medicine.diagnostic_test ,choroidal detachment ,business.industry ,010102 general mathematics ,shallow anterior chamber ,Magnetic resonance imaging ,Idiopathic orbital inflammation ,eye diseases ,idiopathic orbital inflammation ,medicine.anatomical_structure ,Choroidal detachment ,lcsh:RE1-994 ,Cavernous sinus ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,Shallow anterior chamber - Abstract
We report a case of idiopathic orbital inflammation with a shallow anterior chamber and choroidal detachments. This study involved an 87-year-old female patient who presented at our department after becoming aware of the progression of diplopia. Examination of the patient’s right eye revealed proptosis, as well as conjunctival edema with dilated and tortuous blood vessels. The right-eye anterior chamber was shallow, and fundus examination revealed marked choroidal detachments. Magnetic resonance imaging revealed enlargement of the right-orbit extraocular muscles and a suspected compression of the right-orbit superior and inferior ophthalmic veins, yet no expansion of the cavernous sinus. We diagnosed the patient as having idiopathic orbital inflammation in her right orbit, and subsequently started corticosteroid therapy. One week after initiating treatment, the anterior chamber was found to be nearing a normal depth, and the choroidal detachments were found to have disappeared. Our findings revealed that the inflammatory swelling of the extraocular muscle due to idiopathic orbital inflammation resulted in compression of the right-orbit superior and inferior ophthalmic veins, thus leading to an apparent choroidal circulation disorder that presented with a shallow anterior chamber and marked choroidal detachments.
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- 2020
43. Two surgical cases of popliteal venous aneurysm with pulmonary thromboembolism
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Nobuo Takada, Aya Saitou, Tsutomu Inaoka, Tsuyoshi Tabata, Noboru Motomura, Kazuhiro Shimizu, and Yuya Itou
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medicine.medical_specialty ,business.industry ,Medicine ,Radiology, Nuclear Medicine and imaging ,business ,Venous aneurysm ,Surgery - Published
- 2020
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44. Axillary pacemaker generator implantation and direct axillary vein puncture on the infected side for a pacemaker infection on the opposite side to an arteriovenous fistula in a dialysis patient
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Takahiro Nakagami, Yasushi Ohhashi, Hajime Kiyokawa, Takurou Itoh, Keisuke Yamazaki, Mao Takahashi, Takuo Iiduka, Shuuji Satou, Tsuyoshi Kawamura, Hiroshi Mikamo, Mahito Noro, Shunsuke Totani, and Kazuhiro Shimizu
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medicine.medical_specialty ,Generator (computer programming) ,business.industry ,medicine ,Arteriovenous fistula ,Dialysis (biochemistry) ,Axillary vein ,medicine.disease ,business ,Surgery - Published
- 2020
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45. Variation of Salivary IgA During Weight Loss Period Before a Competition Among University Judo Players
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Yujiro Matsuish, Subrina Jesmin, Yukichi Hanaoka, Hiroaki Hiraoka, Fuminori Kimura, Kazuhiro Shimizu, and Koichi Watanabe
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Saliva ,Weight loss ,biology ,Respiratory tract infections ,Competition ,Athletes ,business.industry ,media_common.quotation_subject ,Health condition ,Immunity ,Physiology ,Salivary immunoglobulin A ,General Medicine ,Judo ,biology.organism_classification ,Competition (biology) ,Salivary iga ,medicine ,Increased fatigue ,Original Article ,medicine.symptom ,business ,media_common - Abstract
Background: This study aims to investigate the health condition of university judo athletes during a period of weight loss before a competition, using secretory immunoglobulin A (SIgA) in saliva. Methods: The subjects were 30 university judo athletes, who were divided into three groups: control group (n = 10), under 5% weight loss group (n = 10), and over 5% weight loss group (n = 10). The items evaluated were body weight measurements, salivary SIgA level and its secretion rates, incidences of symptoms of upper respiratory tract infections, and mental state. Results: The over 5% body weight loss group had significantly lower SIgA secretion rates on the first day and third day before the real competition compared to those of the control group. Furthermore, the over 5% body weight loss group had an increased number of symptoms of upper respiratory tract infections. Alterations in mental statuses were also seen, such as decreased vitality and increased fatigue on the day before the competition in the over 5% weight loss group. Conclusions: This study shows that over 5% body weight loss in judo athletes induces a decrease in the salivary SIgA secretion rate and causes health condition of the body and the mind to deteriorate. J Clin Med Res. 2019;11(12):798-806 doi: https://doi.org/10.14740/jocmr3998
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- 2019
46. Comparison of Cardio–Ankle Vascular Index (CAVI) and CAVI0 in Large Healthy and Hypertensive Populations
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Kazuhiro Shimizu, Masanobu Takata, Tomoyuki Yamamoto, Koji Takahashi, Shinichi Tsuda, Mitsuya Maruyama, Kohji Shirai, and Kenji Suzuki
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medicine.medical_specialty ,business.industry ,Healthy population ,Biochemistry (medical) ,030204 cardiovascular system & hematology ,Positive correlation ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Blood pressure ,Internal medicine ,Internal Medicine ,medicine ,Cardiology ,Arterial stiffness ,Cardio-ankle vascular index ,Ankle ,Cardiology and Cardiovascular Medicine ,business ,Body mass index ,030217 neurology & neurosurgery ,Hypertensive group - Abstract
Aim: The cardio-ankle vascular index (CAVI) represents the blood pressure-independent arterial stiffness from the origin of the aorta to the ankle. CAVI0 has been proposed as a variant index. We aimed to clarify the difference between CAVI and CAVI0 among large populations, and to explore reasons of the difference. Methods: The subjects were 5,293 Japanese healthy and 3,338 hypertensive people. Simple and multiple regression analyses were performed using age, sex, body mass index, systolic, and diastolic blood pressure (Pd) as variables. Sub-group analysis was performed by sex and age. The CAVI values with and without adjustment by reference pressure were also compared. Results: CAVI had a positive correlation with Pd, while CAVI0 had a negative correlation with Pd in the healthy population. The CAVI values of the hypertensive group were higher than those of healthy group in both men and women, but the CAVI0 values in women of the hypertensive group in the 30–39 age group was significantly lower than that of the corresponding healthy group. Differences of CAVI values with or without modification using the reference pressure were 1.09% ± 1.38% for the healthy group and 3.68% ± 1.66% for the hypertensive group. Conclusion: CAVI showed the expected values, but CAVI0 showed inexplicable results in the healthy and hypertensive populations. The differences were due to the strong dependency of CAVI0 on Pd. Differences of CAVI values with or without reference pressure were negligible. These results indicate that CAVI obtained by the VaSera system is appropriate, but CAVI0 is not.
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- 2019
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47. A 130-mm/2, 256-Mbit NAND flash with shallow trench isolation technology.
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Kenichi Imamiya, Yoshihisa Sugiura, Hiroshi Nakamura, Toshihiko Himeno, Ken Takeuchi, Tamio Ikehashi, Kazushige Kanda, Koji Hosono, Riichiro Shirota, Seiichi Aritome, Kazuhiro Shimizu, Kazuo Hatakeyama, and Koji Sakui
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- 1999
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48. Effects Of Physical And Psychological Stress On Salivary Nitric Oxide In Young Men: 3321 Board #82 May 30, 8: 00 AM - 9: 30 AM
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Ryouta, Sone, Koichiro, Hayashi, Kazuhiro, Shimizu, Yukichi, Hanaoka, and Koichi, Watanabe
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- 2015
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49. A compact on-chip ECC for low cost flash memories.
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Toru Tanzawa, Tomoharu Tanaka, Ken Takeuchi, Riichiro Shirota, Seiichi Aritome, Hiroshi Watanabe, Gertjan Hemink, Kazuhiro Shimizu, Shinji Sato, Yuji Takeuchi, and Kazunori Ohuchi
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- 1997
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50. The association of
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Nobuhiko, Akazawa, Nao, Ohiwa, Kazuhiro, Shimizu, Natsumi, Suzuki, Hiroshi, Kumagai, Noriyuki, Fuku, and Yasuhiro, Suzuki
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The α-actinin-3 proteins regulate muscle function and are located in the Z-line of the fast skeletal muscle. A common null polymorphism of R577X in α-actinin-3 gene (
- Published
- 2021
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