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Kurihara S, Fukuda N. Correction: Regulation of myocardial contraction as revealed by intracellular Ca 2+ measurements using aequorin. J Physiol Sci 2024; 74:20. [PMID: 38532361 DOI: 10.1186/s12576-024-00915-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Affiliation(s)
- Satoshi Kurihara
- Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan
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Kurihara S, Fukuda N. Regulation of myocardial contraction as revealed by intracellular Ca 2+ measurements using aequorin. J Physiol Sci 2024; 74:12. [PMID: 38383293 PMCID: PMC10882819 DOI: 10.1186/s12576-024-00906-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 02/06/2024] [Indexed: 02/23/2024]
Abstract
Of the ions involved in myocardial function, Ca2+ is the most important. Ca2+ is crucial to the process that allows myocardium to repeatedly contract and relax in a well-organized fashion; it is the process called excitation-contraction coupling. In order, therefore, for accurate comprehension of the physiology of the heart, it is fundamentally important to understand the detailed mechanism by which the intracellular Ca2+ concentration is regulated to elicit excitation-contraction coupling. Aequorin was discovered by Shimomura, Johnson and Saiga in 1962. By taking advantage of the fact that aequorin emits blue light when it binds to Ca2+ within the physiologically relevant concentration range, in the 1970s and 1980s, physiologists microinjected it into myocardial preparations. By doing so, they proved that Ca2+ transients occur upon membrane depolarization, and tension development (i.e., actomyosin interaction) subsequently follows, dramatically advancing the research on cardiac excitation-contraction coupling.
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Affiliation(s)
- Satoshi Kurihara
- Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan.
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, 105-8461, Japan
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Kurihara S, Nakajima M, Kaszynski RH, Yamamoto Y, Santo K, Takane R, Tokuno H, Ishihata A, Ando H, Miwa M, Hamada S, Nakano T, Shirokawa M, Goto H, Yamaguchi Y. Prevalence of COVID-19 Mimics in the Emergency Department. Intern Med 2021; 60:3087-3092. [PMID: 34334560 PMCID: PMC8545642 DOI: 10.2169/internalmedicine.6434-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Objective Due to the lack of specific clinical manifestations and symptoms, it is difficult to distinguish COVID-19 from mimics. A common pitfall is to rush to make a diagnosis when encountering a patient with COVID-19-like symptoms. The present study describes a series of COVID-19 mimics using an outpatient database collected from a designated COVID-19 healthcare facility in Tokyo, Japan. Methods We established an emergency room (ER) tailored specifically for patients with suspected or confirmed COVID-19 called the "COVID-ER." In this single-center retrospective cohort study, we enrolled patients who visited the COVID-ER from February 1 to September 5, 2020. The outcomes included the prevalence of COVID-19, admission, potentially fatal diseases and final diagnosis. Results We identified 2,555 eligible patients. The median age was 38 (interquartile range, 26-57) years old. During the study period, the prevalence of COVID-19 was 17.9% (457/2,555). Non-COVID-19 diagnoses accounted for 82.1% of all cases. The common cold had the highest prevalence and accounted for 33.0% of all final diagnoses, followed by gastroenteritis (9.4%), urinary tract infections (3.8%), tonsillitis (2.9%), heat stroke (2.6%) and bacterial pneumonia (2.1%). The prevalence of potentially fatal diseases was 14.2% (298/2,098) among non-COVID-19 patients. Conclusion Several potentially fatal diseases remain masked among the wave of COVID-19 mimics. It is imperative that a thorough differential diagnostic panel be considered prior to the rendering of a COVID-19 diagnosis.
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Affiliation(s)
- Satoshi Kurihara
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Mikio Nakajima
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
- Department of Trauma and Critical Care Medicine, Kyorin University School of Medicine, Japan
| | - Richard H Kaszynski
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | | | - Koichiro Santo
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Ryo Takane
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Hayato Tokuno
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Ayaka Ishihata
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Hitoshi Ando
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Maki Miwa
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Shoichiro Hamada
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
- Department of Trauma and Critical Care Medicine, Kyorin University School of Medicine, Japan
| | - Tomotsugu Nakano
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Masamitsu Shirokawa
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Hideaki Goto
- Department of Emergency and General Medicine, Tokyo Metropolitan Hiroo Hospital, Japan
- Emergency and Critical Care Center, Tokyo Metropolitan Hiroo Hospital, Japan
| | - Yoshihiro Yamaguchi
- Department of Trauma and Critical Care Medicine, Kyorin University School of Medicine, Japan
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Takaya E, Takeichi Y, Ozaki M, Kurihara S. Sequential semi-supervised segmentation for serial electron microscopy image with small number of labels. J Neurosci Methods 2021; 351:109066. [PMID: 33417965 DOI: 10.1016/j.jneumeth.2021.109066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/29/2020] [Accepted: 01/02/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Segmentation of electron microscopic continuous section images by deep learning has attracted attention as a technique to reduce the cost of annotation for researchers attempting to make observations using 3D reconstruction methods. However, when the observed samples are rare, or scanning circumstances are unstable, pursuing generalization performance for newly obtained samples is not appropriate. NEW METHODS We assume a transductive setting that predicts all labels in a dataset from only partially obtained labels while avoiding the pursuit of generalization performance for unknown data. Then, we propose sequential semi-supervised segmentation (4S), which semi-automatically extracts neural regions from electron microscopy image stacks. This method focuses on the fact that adjacent images have a strong correlation in serial images. Our 4S repeats training, inference, and pseudo-labeling using a minimal number of teacher labels and performs segmentation on all slices. RESULT Our experiments using two types of serial section images showed effectiveness in terms of both quality and quantity. In addition, we experimentally clarified the effect of the number and position of teacher labels on performance. COMPARISON WITH EXISTING METHODS Compared with supervised learning when a small number of labeled data was obtained, the performance of the proposed method was shown to be superior. CONCLUSION Our 4S leverages a limited number of labeled data and a large amount of unlabeled data to extract neural regions from serial image stacks in a transductive setting. We plan to develop this method as a core module of a general-purpose annotation tool in our future work.
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Affiliation(s)
- Eichi Takaya
- School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, Kanagawa, Japan.
| | - Yusuke Takeichi
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Mamiko Ozaki
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan; Division of Strategic Research of the Humanosphere, Research Institute of Sustainable Humanosphere, Kyoto University, Kyoto, Japan; KYOUSEI Science Center for Life and Nature, Nara Women's University, Nara, Japan; RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Satoshi Kurihara
- Department of Industrial and Systems Engineering, Faculty of Science and Technology, Keio University, Kanagawa, Japan
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Ishii H, Kurihara S, Hirai K, Yanai K, Ookawara S, Morishita Y. Warfarin-induced impairment of bone material quality in a patient undergoing maintenance hemodialysis: A case report. Medicine (Baltimore) 2020; 99:e20724. [PMID: 32569210 PMCID: PMC7310883 DOI: 10.1097/md.0000000000020724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION The use of warfarin in patients undergoing hemodialysis is associated with decreased bone mineral density and an increased incidence of bone fracture. However, no studies to date have directly estimated bone quality with bone histomorphometry in patients with bone abnormalities who are taking warfarin and undergoing hemodialysis. PATIENT CONCERNS A 47-year-old female with Noonan syndrome presented with progressive bilateral lower extremity pain on walking, and skin sclerosis. She had been undergoing maintenance hemodialysis for 25 years following 2 years of peritoneal dialysis for chronic glomerulonephritis. She had been taking warfarin as an anticoagulant agent for 13 years after she underwent an aortic valve replacement. DIAGNOSIS Warfarin-induced impairment of bone material quality. INTERVENTIONS AND OUTCOMES Histomorphometric analysis of the bone biopsy specimens showed impairment in bone calcification processes, a high turnover of bone remodeling, low bone volume, and mild fibrosis. The bone abnormality could not be categorized into any type of representative bone disease classification such as osteitis fibrosa, osteomalacia, adynamic bone disease, uremic osteodystrophy, or hyperparathyroidism, but was consistent with warfarin-induced impairment of bone material quality. CONCLUSION Warfarin can induce impairment of bone material quality in a patient undergoing hemodialysis.
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Affiliation(s)
- Hiroki Ishii
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University
| | | | - Keiji Hirai
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University
| | - Katsunori Yanai
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University
| | - Susumu Ookawara
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University
| | - Yoshiyuki Morishita
- Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University
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Hanai K, Akamatsu M, Fujimori A, Higashi H, Horie Y, Itaya Y, Ito M, Kanamaru T, Kawaguchi H, Kikuchi K, Kobayashi H, Komatsu M, Kubota T, Kudo K, Kurihara S, Masakane I, Mera J, Mizuiri S, Moriyama K, Nagasawa J, Nagata S, Nakagawa Y, Nakazato S, Nishi T, Noma Y, Odaguchi N, Okuno S, Osada S, Ozasa H, Sato S, Sawada T, Shimajiri T, Shimamoto Y, Suda M, Suzuki T, Suzuki H, Takahashi M, Takahashi H, Takahashi T, Takebayashi Y, Takeda M, Tamura H, Tanaka Y, Tokunaka S, Tsuda S, Ueda M, Yamaguchi I, Yamamoto H, Uchigata Y, Babazono T. Usefulness of glycated albumin as a predictor of mortality in chronic hemodialysis patients with diabetes: a multi-center, prospective cohort study. Ren Replace Ther 2020. [DOI: 10.1186/s41100-020-00264-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
The association of glycated albumin (GA) with mortality is unclear in chronic hemodialysis patients with diabetes. We investigated the usefulness of GA by comparing it with hemoglobin A1c (HbA1c) in this patient population.
Research design and methods
This was a multi-center, prospective cohort study of 841 Japanese chronic hemodialysis patients with diabetes. There were 235 women and 606 men included, with a mean age of 64 years. The primary and secondary endpoints were the incidence of all-cause and cause-specific mortality, respectively. The hazard ratios of GA and HbA1c for the endpoints were estimated using the values at baseline and during the study period.
Results
During the mean follow-up period of 3.1 years, there were 184 deceased cases, in which 30 and 154 resulted from atherosclerotic cardiovascular disease (ASCVD) and non-ASCVD, respectively. The hazard ratio for a 1% increase in GA was 1.033 (95% confidence interval 1.006–1.060, p = 0.017) for all-cause mortality with a statistical significance when GA was treated as a time dependent variable, but not when the baseline levels or the mean levels during the follow-up period were used in the analysis (p = 0.815 and 0.517, respectively). GA was a significant predictor for ASCVD-related mortality in the above 3 models, but was not for non-ASCVD mortality. Higher levels of HbA1c were only associated with ASCVD-related mortality when HbA1c was treated as a time-dependent variable.
Conclusions
GA may be useful compared to HbA1c for predicting all-cause and ASCVD-related mortality in Japanese patients with diabetes undergoing chronic hemodialysis.
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Kurihara S, Tani Y, Tateishi K, Yuri T, Kitada H, Sugishita N, Fukuda Y, Ishikawa I, Shinoda A, Hayakawa Y. Allergic Eosinophilic Dermatitis Due to Silicone Rubber: A Rare but Troublesome Complication of the Tenckhoff Catheter. Perit Dial Int 2020. [DOI: 10.1177/089686088500500118] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A 42-year-old Japanese woman developed an eczematous skin rash around the catheter exit during continuous ambulatory peritoneal dialysis (CAPD). The same kind of lesion developed around a Scribner shunt exit. Skin biopsy indicated chronic eosinophilic dermatitis. In the patch test she developed an allergic reaction to the silicone rubber catheter but not to the antiseptic solutions. Based on these findings, we concluded that her “eczematous” rash represented an allergic response to silicone rubber in the peritoneal catheter. To this date the literature contains no reports of such a catheter complication in CAPD. Catheter complications in patients on CAPD are mainly infection and mechanical dysfunction such as poor drainage or leaks (I, 2). Eosinophilic dermatitis around the catheter exit caused by the silicone rubber is extremely uncommon (3). As yet no reports have been published concerning this rare catheter complication.
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Affiliation(s)
- Satoshi Kurihara
- From the Division of Nephrology, Department of Internal Medicine
| | - Yoshio Tani
- From the Division of Nephrology, Department of Internal Medicine
| | - Keita Tateishi
- From the Division of Nephrology, Department of Internal Medicine
| | - Takehisa Yuri
- From the Division of Nephrology, Department of Internal Medicine
| | - Hirohisa Kitada
- From the Division of Nephrology, Department of Internal Medicine
| | | | - Yoshihiro Fukuda
- From the Division of Nephrology, Department of Internal Medicine
| | - Isao Ishikawa
- From the Division of Nephrology, Department of Internal Medicine
| | - Akira Shinoda
- From the Division of Nephrology, Department of Internal Medicine
| | - Yukinori Hayakawa
- Department of Dermatology, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa-ken, 920–02, Japan
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Takeichi Y, Uebi T, Miyazaki N, Murata K, Yasuyama K, Inoue K, Suzaki T, Kubo H, Kajimura N, Takano J, Omori T, Yoshimura R, Endo Y, Hojo MK, Takaya E, Kurihara S, Tatsuta K, Ozaki K, Ozaki M. Putative Neural Network Within an Olfactory Sensory Unit for Nestmate and Non-nestmate Discrimination in the Japanese Carpenter Ant: The Ultra-structures and Mathematical Simulation. Front Cell Neurosci 2018; 12:310. [PMID: 30283303 PMCID: PMC6157317 DOI: 10.3389/fncel.2018.00310] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/27/2018] [Indexed: 11/13/2022] Open
Abstract
Ants are known to use a colony-specific blend of cuticular hydrocarbons (CHCs) as a pheromone to discriminate between nestmates and non-nestmates and the CHCs were sensed in the basiconic type of antennal sensilla (S. basiconica). To investigate the functional design of this type of antennal sensilla, we observed the ultra-structures at 2D and 3D in the Japanese carpenter ant, Camponotus japonicus, using a serial block-face scanning electron microscope (SBF-SEM), and conventional and high-voltage transmission electron microscopes. Based on the serial images of 352 cross sections of SBF-SEM, we reconstructed a 3D model of the sensillum revealing that each S. basiconica houses > 100 unbranched dendritic processes, which extend from the same number of olfactory receptor neurons (ORNs). The dendritic processes had characteristic beaded-structures and formed a twisted bundle within the sensillum. At the "beads," the cell membranes of the processes were closely adjacent in the interdigitated profiles, suggesting functional interactions via gap junctions (GJs). Immunohistochemistry with anti-innexin (invertebrate GJ protein) antisera revealed positive labeling in the antennae of C. japonicus. Innexin 3, one of the five antennal innexin subtypes, was detected as a dotted signal within the S. basiconica as a sensory organ for nestmate recognition. These morphological results suggest that ORNs form an electrical network via GJs between dendritic processes. We were unable to functionally certify the electric connections in an olfactory sensory unit comprising such multiple ORNs; however, with the aid of simulation of a mathematical model, we examined the putative function of this novel chemosensory information network, which possibly contributes to the distinct discrimination of colony-specific blends of CHCs or other odor detection.
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Affiliation(s)
- Yusuke Takeichi
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Tatsuya Uebi
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | | | | | - Kouji Yasuyama
- Division of Biology, Department of Natural Sciences, Kawasaki Medical School, Kurashiki, Japan
| | - Kanako Inoue
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Ibaraki, Japan
| | - Toshinobu Suzaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Hideo Kubo
- Department of Mathematics, Faculty of Sciences, Hokkaido University, Sapporo, Japan
| | - Naoko Kajimura
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Jo Takano
- Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Toshiaki Omori
- Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Ryoichi Yoshimura
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | - Yasuhisa Endo
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | - Masaru K Hojo
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
| | - Eichi Takaya
- Graduate School of Information Systems, The University of Electro-Communications, Chofu, Japan
| | - Satoshi Kurihara
- Graduate School of Information Systems, The University of Electro-Communications, Chofu, Japan
| | - Kenta Tatsuta
- Department of Biological Science, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan
| | - Koichi Ozaki
- Department of Biological Science, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan
| | - Mamiko Ozaki
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan
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Abstract
Traffic congestion is a serious problem for people living in urban areas, causing social problems such as time loss, economical loss, and environmental pollution. Therefore, we propose a multi-agent-based traffic light control framework for intelligent transport systems. Achieving consistent traffic flow necessitates the real-time adaptive coordination of traffic lights; however, many conventional approaches are of the centralized control type and do not have this feature. Our multi-agent-based control framework combines both indirect and direct coordination. Reaction to dynamic traffic flow is attained by indirect coordination, whereas green-wave formation, which is a systematic traffic flow control strategy involving several traffic lights, is attained by direct coordination. We present the detailed mechanism of our framework and verify its effectiveness using simulation to carry out a comparative evaluation.
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Tanaka K, Shibakusa T, Kurihara S. SUN-PP030: Effect of the Oral Administration of Cystine on the Immune System in Mice. Clin Nutr 2015. [DOI: 10.1016/s0261-5614(15)30181-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Imajoh M, Fujioka H, Furusawa K, Tamura K, Yamasaki K, Kurihara S, Yamane J, Kawai K, Oshima S. Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV-3) and possible latency of CyHV-3 by temperature shift in the cells. J Fish Dis 2015; 38:507-514. [PMID: 24820532 DOI: 10.1111/jfd.12252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/24/2014] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
A new cell line named CCF-K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV-3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV-3-infected CCF-K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV-3 was produced stably in CCF-K104 cells over 30 viral passages. Our findings showed that CCF-K104 is a useful cell line for isolation and productive replication of CyHV-3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real-time PCR showed that CyHV-3 was present with low viral DNA loads, suggesting that CyHV-3 may establish latent infection in CCF-K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV-3 genome arranged in a head-to-tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV-3.
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Affiliation(s)
- M Imajoh
- Laboratory of Fish Disease, Faculty of Agriculture, Kochi University, Nankoku, Kochi, Japan
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Kuwabara Y, Katayama A, Kurihara S, Yonezawa M, Ouchi N, Sawa R, Takeshita T. Progesterone transcriptionally inhibits LPS-induced matrix metalloproteinase up-regulation in human cervical fibroblast cells. J Reprod Immunol 2014. [DOI: 10.1016/j.jri.2014.09.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Tanaka K, Kurihara S, Shibakusa T, Chiba Y, Mikami T. PP279-SUN: Cystine Improves Survival Rate in LPS-Induced Sepsis Mouse Model. Clin Nutr 2014. [DOI: 10.1016/s0261-5614(14)50320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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14
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Okada Y, Ikeda K, Shinoda K, Toriumi F, Sakaki T, Kazama K, Numao M, Noda I, Kurihara S. SIR-Extended Information Diffusion Model of False Rumor and its Prevention Strategy for Twitter. J Adv Comput Intell Intell Inform 2014. [DOI: 10.20965/jaciii.2014.p0598] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nowadays, users of Twitter, one of famous social networking service, have rapidly increased in number, and many people have been exchanging information by Twitter. When the Great East Japan Earthquake struck in 2011, people were able to obtain information from social networking services. Though Twitter played an important role, one problem was especially pointed out: false rumor diffusion. In this study, we propose an information diffusion model based on the SIR model and discuss how to prevent false rumor diffusion.
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Ikeda K, Ogawa Y, Kajino C, Deguchi S, Kurihara S, Tashima T, Goto W, Nishiguchi Y, Tokunaga S, Fukushima H, Inoue T. The influence of axillary reverse mapping related factors on lymphedema in breast cancer patients. Eur J Surg Oncol 2014; 40:818-23. [DOI: 10.1016/j.ejso.2014.03.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 03/24/2014] [Accepted: 03/25/2014] [Indexed: 12/01/2022] Open
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Ise M, Yasuda F, Suzaki R, Kurihara S, Konohana I. Skin lesions in a patient with IgG4-related disease. Clin Exp Dermatol 2014; 39:713-6. [DOI: 10.1111/ced.12372] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2014] [Indexed: 12/24/2022]
Affiliation(s)
- M. Ise
- Division of Dermatology; Hiratsuka City Hospital; Hiratsuka Japan
| | - F. Yasuda
- Division of Dermatology; Hiratsuka City Hospital; Hiratsuka Japan
| | - R. Suzaki
- Division of Dermatology; Hiratsuka City Hospital; Hiratsuka Japan
| | | | - I. Konohana
- Division of Dermatology; Hiratsuka City Hospital; Hiratsuka Japan
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Morimoto S, Hongo K, Kusakari Y, Komukai K, Kawai M, O-Uchi J, Nakayama H, Asahi M, Otsu K, Yoshimura M, Kurihara S. Genetic modulation of the SERCA activity does not affect the Ca(2+) leak from the cardiac sarcoplasmic reticulum. Cell Calcium 2013; 55:17-23. [PMID: 24290743 DOI: 10.1016/j.ceca.2013.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
Abstract
The Ca(2+) content in the sarcoplasmic reticulum (SR) determines the amount of Ca(2+) released, thereby regulating the magnitude of Ca(2+) transient and contraction in cardiac muscle. The Ca(2+) content in the SR is known to be regulated by two factors: the activity of the Ca(2+) pump (SERCA) and Ca(2+) leak through the ryanodine receptor (RyR). However, the direct relationship between the SERCA activity and Ca(2+) leak has not been fully investigated in the heart. In the present study, we evaluated the role of the SERCA activity in Ca(2+) leak from the SR using a novel saponin-skinned method combined with transgenic mouse models in which the SERCA activity was genetically modulated. In the SERCA overexpression mice, the Ca(2+) uptake in the SR was significantly increased and the Ca(2+) transient was markedly increased. However, Ca(2+) leak from the SR did not change significantly. In mice with overexpression of a negative regulator of SERCA, sarcolipin, the Ca(2+) uptake by the SR was significantly decreased and the Ca(2+) transient was markedly decreased. Again, Ca(2+) leak from the SR did not change significantly. In conclusion, the selective modulation of the SERCA activity modulates Ca(2+) uptake, although it does not change Ca(2+) leak from the SR.
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Affiliation(s)
- Satoshi Morimoto
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kenichi Hongo
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
| | - Yoichiro Kusakari
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kimiaki Komukai
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Makoto Kawai
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Jin O-Uchi
- Center for Translational Medicine, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, USA
| | - Hiroyuki Nakayama
- Department of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Michio Asahi
- Department of Pharmacology, Faculty of Medicine, Osaka Medical College, Osaka, Japan
| | - Kinya Otsu
- Cardiovascular Division, King's College London, London, United Kingdom
| | - Michihiro Yoshimura
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Satoshi Kurihara
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
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Tanaka K, Kurihara S, Shibakusa T, Chiba Y. PP253-SUN CYSTINE SUPPRESSES INFLAMMATORY REACTION INDUCED BY LPS THROUGH AUGMENTATION OF INTERLEUKIN-10 PRODUCTION. Clin Nutr 2013. [DOI: 10.1016/s0261-5614(13)60298-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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19
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Shibakusa T, Kurihara S, Tanaka K, Chiba Y, Tsuchiya T, Oyama A. PP255-SUN SUPPRESSION OF FEVER BY ORAL ADMINISTRATION OF THE AMINO ACIDS, CYSTINE AND THEANINE, IN LPS-INDUCED INFLAMMATION MODEL. Clin Nutr 2013. [DOI: 10.1016/s0261-5614(13)60300-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Hirata M, Tashiro Y, Aizawa K, Endo K, Hirata M, Tashiro Y, Endo K, Aizawa K, Serizawa K, Hirata M, Yogo K, Tashiro Y, Endo K, Cases A, Portoles J, Calls J, Martinez-Castelao A, Munar MA, Segarra A, Samouilidou E, Pantelias K, Petras D, Mpakirtzi T, Pipili C, Chatzivasileiou G, Vasiliou K, Denda E, Grapsa E, Tzanatos H, Shoji S, Inaba M, Tomosugi N, Okuno S, Ichii M, Yamakawa T, Kurihara S, Barsan L, Stanciu A, Stancu S, Capusa C, Bratescu L, Mircescu G, Barsan L, Stanciu A, Stancu S, Capusa C, Mircescu G, Kuo KL, Hung SC, Lee TS, Tarng DC, Nistor I, Covic A, Goldsmith D, Garrido P, Fernandes J, Ribeiro S, Vala H, Parada B, Alves R, Belo L, Costa E, Santos-Silva A, Reis F, Abdulnabi K, Ullah A, Abdulateef A, Howse M, Khalil A, Fouqueray B, Hoffmann M, Addison J, Manamley N, Stamopoulos D, Mpakirtzi N, Afentakis N, Grapsa E, Yu KH, Chou J, Klaus S, Schaddelee M, Kashiwa M, Takada A, Neff T, Galle J, Claes K, Di Giulio S, Guerin A, Herlitz H, Kiss I, Wirnsberger G, Manamley N, Addison J, Fouqueray B, Froissart M, Winearls C, Martinez Castelao A, Cases Amenos A, Torre Carballada A, Torralba Iranzo FJ, Bronsoms Artero JM, Toran Monserrat D, Valles Prats M, Merino JL, Espejo B, Bueno B, Amezquita Y, Paraiso V, Kiss Z, Kerkovits L, Ambrus C, Kulcsar I, Szegedi J, Benke A, Borbas B, Ferenczi S, Hengsperger M, Kazup S, Nagy L, Nemeth J, Rozinka A, Szabo T, Szelestei T, Toth E, Varga G, Wagner G, Zakar G, Gergely L, Kiss I, Exarchou K, Tanahill N, Anthoney A, Khalil A, Ahmed S, Capusa C, Oprican R, Stanciu A, Lipan M, Stancu S, Chirculescu B, Mircescu G, Ferenczi S, Roger S, Malecki R, Farouk M, Dellanna F, Thomas M, Manamley N, Touam M, Chantrel F, Bouiller M, Hurot JM, Raphael T, Testa A, Veillon S, Vendrely B, Masoumi Z, Ahmadpoor P, Ghaderian SMH, Nafar M, Samavat S, Samadian F, Poorrezagholi F, Shahidi M, Riccio E, Visciano B, Capuano I, Memoli A, Mozzillo G, Memoli B, Pisani A. Anaemia in CKD 1-5. Nephrol Dial Transplant 2013. [DOI: 10.1093/ndt/gft131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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21
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O-Uchi J, Komukai K, Kusakari Y, Morimoto S, Kawai M, Jhun BS, Hurst S, Hongo K, Sheu SS, Kurihara S. Alpha1-adrenenoceptor stimulation inhibits cardiac excitation-contraction coupling through tyrosine phosphorylation of beta1-adrenoceptor. Biochem Biophys Res Commun 2013; 433:188-93. [PMID: 23454381 DOI: 10.1016/j.bbrc.2013.02.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 02/14/2013] [Indexed: 11/25/2022]
Abstract
Adrenoceptor stimulation is a key determinant of cardiac excitation-contraction coupling mainly through the activation of serine/threonine kinases. However, little is known about the role of protein tyrosine kinases (PTKs) activated by adrenergic signaling on cardiac excitation-contraction coupling. A cytoplasmic tyrosine residue in β1-adrenoceptor is estimated to regulate Gs-protein binding affinity from crystal structure studies, but the signaling pathway leading to the phosphorylation of these residues is unknown. Here we show α1-adrenergic signaling inhibits β-adrenergically activated Ca(2+) current, Ca(2+) transients and contractile force through phosphorylation of tyrosine residues in β1-adrenoceptor by PTK. Our results indicate that inhibition of β-adrenoceptor-mediated Ca(2+) elevation by α1-adrenoceptor-PTK signaling serves as an important regulatory feedback mechanism when the catecholamine level increases to protect cardiomyocytes from cytosolic Ca(2+) overload.
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Affiliation(s)
- Jin O-Uchi
- Center for Translational Medicine, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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22
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Shoji S, Inaba M, Tomosugi N, Okuno S, Ichii M, Yamakawa T, Kurihara S. Greater potency of darbepoetin-αthan erythropoietin in suppression of serum hepcidin-25 and utilization of iron for erythropoiesis in hemodialysis patients. Eur J Haematol 2013; 90:237-44. [DOI: 10.1111/ejh.12067] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2012] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Naohisa Tomosugi
- Division of Advanced Medicine; Medical Research Institute; Kanazawa Medical University; Ishikawa; Japan
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23
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Gejyo F, Amano I, Ando T, Ishida M, Obayashi S, Ogawa H, Ono T, Kanno Y, Kitaoka T, Kukita K, Kurihara S, Sato M, Shin J, Suzuki M, Takahashi S, Taguma Y, Takemoto Y, Nakazawa R, Nakanishi T, Nakamura H, Hara S, Hiramatsu M, Furuya R, Masakane I, Tsuchida K, Motomiya Y, Morita H, Yamagata K, Yoshiya K, Yamakawa T. Survey of the Effects of a Column for Adsorption of β2-Microglobulin in Patients With Dialysis-Related Amyloidosis in Japan. Ther Apher Dial 2012; 17:40-7. [DOI: 10.1111/j.1744-9987.2012.01130.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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24
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Tanaka E, Konishi M, Kurihara S. Role of Ca(2+) in the rapid cooling-induced Ca(2+) release from sarcoplasmic reticulum in ferret cardiac muscles. J Physiol Sci 2012; 62:241-50. [PMID: 22431072 PMCID: PMC3337403 DOI: 10.1007/s12576-012-0203-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 02/13/2012] [Indexed: 11/04/2022]
Abstract
Rapid lowering of the solution temperature (rapid cooling, RC) from 24 to 3°C within 3 s releases considerable amounts of Ca2+ from the sarcoplasmic reticulum (SR) in mammalian cardiac muscles. In this study, we investigated the intracellular mechanism of RC-induced Ca2+ release, especially the role of Ca2+, in ferret ventricular muscle. Saponin-treated skinned trabeculae were placed in a glass capillary, and the amount of Ca2+ released from the SR by RC and caffeine (50 mM) was measured with fluo-3. It was estimated that in the presence of ATP about 45% of the Ca2+ content in the SR was released by RC. The amount of SR Ca2+ released by RC was unchanged by the replacement of ATP by AMP-PCP (a non-hydrolysable ATP analogue and agonist for the ryanodine receptor but not for the Ca2+ pump of SR), suggesting that the suppression of the Ca2+ pump of SR at low temperature might not be a major mechanism in RC-induced Ca2+ release. The free Ca2+ concentration of the solution used for triggering RC-induced Ca2+ release was estimated to be only about 20 nM with fluo-3 or aequorin. When this solution was applied to the preparation at 3°C, only a small amount of Ca2+ was released from SR presumably by the Ca2+-induced Ca2+ release (CICR) mechanism. Thus, in mammalian cardiac muscles, RC releases a part of the (<50%) stored Ca2+ contained in the SR, and the mechanism of RC-induced Ca2+ release may differ from that of CICR, which is thought to play a role in frog skeletal muscle fibres that express ryanodine receptors of different types.
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Affiliation(s)
- Etsuko Tanaka
- Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
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25
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Shintani SA, Yamane M, Oyama K, Kurihara S, Ishiwata S, Fukuda N. Analyses of Sarcomeric Self-Oscillatory Properties of Rat Neonatal Cardiomyocytes. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.1934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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26
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Kurihara S. [Thoughts on the Physiological Society of Japan]. Nihon Seirigaku Zasshi 2012; 74:4-6. [PMID: 22423405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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27
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Serizawa T, Terui T, Kagemoto T, Mizuno A, Shimozawa T, Kobirumaki F, Ishiwata S, Kurihara S, Fukuda N. Real-time measurement of the length of a single sarcomere in rat ventricular myocytes: a novel analysis with quantum dots. Am J Physiol Cell Physiol 2011; 301:C1116-27. [DOI: 10.1152/ajpcell.00161.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As the dynamic properties of cardiac sarcomeres are markedly changed in response to a length change of even ∼0.1 μm, it is imperative to quantitatively measure sarcomere length (SL). Here we show a novel system using quantum dots (QDs) that enables a real-time measurement of the length of a single sarcomere in cardiomyocytes. First, QDs were conjugated with anti-α-actinin antibody and applied to the sarcomeric Z disks in isolated skinned cardiomyocytes of the rat. At partial activation, spontaneous sarcomeric oscillations (SPOC) occurred, and QDs provided a quantitative measurement of the length of a single sarcomere over the broad range (i.e., from ∼1.7 to ∼2.3 μm). It was found that the SPOC amplitude was inversely related to SL, but the period showed no correlation with SL. We then treated intact cardiomyocytes with the mixture of the antibody-QDs and FuGENE HD, and visualized the movement of the Z lines/T tubules. At a low frequency of 1 Hz, the cycle of the motion of a single sarcomere consisted of fast shortening followed by slow relengthening. However, an increase in stimulation frequency to 3–5 Hz caused a phase shift of shortening and relengthening due to acceleration of relengthening, and the waveform became similar to that observed during SPOC. Finally, the anti-α-actinin antibody-QDs were transfected from the surface of the beating heart in vivo. The striated patterns with ∼1.96-μm intervals were observed after perfusion under fluorescence microscopy, and an electron microscopic observation confirmed the presence of QDs in and around the T tubules and Z disks, but primarily in the T tubules, within the first layer of cardiomyocytes of the left ventricular wall. Therefore, QDs are a useful tool to quantitatively analyze the movement of single sarcomeres in cardiomyocytes, under various experimental settings.
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Affiliation(s)
- Takahiro Serizawa
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | - Takako Terui
- Department of Cell Physiology, The Jikei University School of Medicine,
| | - Tatsuya Kagemoto
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | - Akari Mizuno
- Department of Cell Physiology, The Jikei University School of Medicine,
- Department of Physics, Waseda University, and
| | | | - Fuyu Kobirumaki
- Department of Cell Physiology, The Jikei University School of Medicine,
| | | | - Satoshi Kurihara
- Department of Cell Physiology, The Jikei University School of Medicine,
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine,
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28
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Udaka J, Terui T, Ohtsuki I, Marumo K, Ishiwata S, Kurihara S, Fukuda N. Depressed contractile performance and reduced fatigue resistance in single skinned fibers of soleus muscle after long-term disuse in rats. J Appl Physiol (1985) 2011; 111:1080-7. [DOI: 10.1152/japplphysiol.00330.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Long-term disuse results in atrophy in skeletal muscle, which is characterized by reduced functional capability, impaired locomotor condition, and reduced resistance to fatigue. Here we show how long-term disuse affects contractility and fatigue resistance in single fibers of soleus muscle taken from the hindlimb immobilization model of the rat. We found that long-term disuse results in depression of caffeine-induced transient contractions in saponin-treated single fibers. However, when normalized to maximal Ca2+-activated force, the magnitude of the transient contractions became similar to that in control fibers. Control experiments indicated that the active force depression in disused muscle is not coupled with isoform switching of myosin heavy chain or troponin, or with disruptions of sarcomere structure or excessive internal sarcomere shortening during contraction. In contrast, our electronmicroscopic observation supported our earlier observation that interfilament lattice spacing is expanded after disuse. Then, to investigate the molecular mechanism of the reduced fatigue resistance in disused muscle, we compared the inhibitory effects of inorganic phosphate (Pi) on maximal Ca2+-activated force in control vs. disused fibers. The effect of Pi was more pronounced in disused fibers, and it approached that observed in control fibers after osmotic compression. These results suggest that contractile depression in disuse results from the lowering of myofibrillar force-generating capacity, rather than from defective Ca2+ mobilization, and the reduced resistance to fatigue is from an enhanced inhibitory effect of Pi coupled with a decrease in the number of attached cross bridges, presumably due to lattice spacing expansion.
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Affiliation(s)
- Jun Udaka
- Departments of 1Cell Physiology,
- Orthopedic Surgery, and
| | - Takako Terui
- Departments of 1Cell Physiology,
- Anesthesiology, The Jikei University School of Medicine, Tokyo; and
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29
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Fukuda N, Inoue T, Yamane M, Terui T, Kobirumaki F, Ohtsuki I, Ishiwata S, Kurihara S. Sarcomere length-dependent Ca2+ activation in skinned rabbit psoas muscle fibers: coordinated regulation of thin filament cooperative activation and passive force. J Physiol Sci 2011; 61:515-23. [PMID: 21901640 PMCID: PMC3204045 DOI: 10.1007/s12576-011-0173-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 08/10/2011] [Indexed: 12/01/2022]
Abstract
In skeletal muscle, active force production varies as a function of sarcomere length (SL). It has been considered that this SL dependence results simply from a change in the overlap length between the thick and thin filaments. The purpose of this study was to provide a systematic understanding of the SL-dependent increase in Ca2+ sensitivity in skeletal muscle, by investigating how thin filament “on–off” switching and passive force are involved in the regulation. Rabbit psoas muscles were skinned, and active force measurements were taken at various Ca2+ concentrations with single fibers, in the short (2.0 and 2.4 μm) and long (2.4 and 2.8 μm) SL ranges. Despite the same magnitude of SL elongation, the SL-dependent increase in Ca2+ sensitivity was more pronounced in the long SL range. MgADP (3 mM) increased the rate of rise of active force and attenuated SL-dependent Ca2+ activation in both SL ranges. Conversely, inorganic phosphate (Pi, 20 mM) decreased the rate of rise of active force and enhanced SL-dependent Ca2+ activation in both SL ranges. Our analyses revealed that, in the absence and presence of MgADP or Pi, the magnitude of SL-dependent Ca2+ activation was (1) inversely correlated with the rate of rise of active force, and (2) in proportion to passive force. These findings suggest that the SL dependence of active force in skeletal muscle is regulated via thin filament “on–off” switching and titin (connectin)-based interfilament lattice spacing modulation in a coordinated fashion, in addition to the regulation via the filament overlap.
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Affiliation(s)
- Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan.
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Fukuda N, Terui T, Ohtsuki I, Ishiwata S, Kurihara S. Titin and troponin: central players in the frank-starling mechanism of the heart. Curr Cardiol Rev 2011; 5:119-24. [PMID: 20436852 PMCID: PMC2805814 DOI: 10.2174/157340309788166714] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 09/17/2008] [Accepted: 09/17/2008] [Indexed: 01/15/2023] Open
Abstract
The basis of the Frank-Starling mechanism of the heart is the intrinsic ability of cardiac muscle to produce greater active force in response to stretch, a phenomenon known as length-dependent activation. A feedback mechanism transmitted from cross-bridge formation to troponin C to enhance Ca2+ binding has long been proposed to account for length-dependent activation. However, recent advances in muscle physiology research technologies have enabled the identification of other factors involved in length-dependent activation. The striated muscle sarcomere contains a third filament system composed of the giant elastic protein titin, which is responsible for most passive stiffness in the physiological sarcomere length range. Recent studies have revealed a significant coupling of active and passive forces in cardiac muscle, where titin-based passive force promotes cross-bridge recruitment, resulting in greater active force production in response to stretch. More currently, the focus has been placed on the troponin-based “on-off” switching of the thin filament state in the regulation of length-dependent activation. In this review, we discuss how myocardial length-dependent activation is coordinately regulated by sarcomere proteins.
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Affiliation(s)
- Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
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Terui T, Shimamoto Y, Yamane M, Kobirumaki F, Ohtsuki I, Ishiwata S, Kurihara S, Fukuda N. Regulatory mechanism of length-dependent activation in skinned porcine ventricular muscle: role of thin filament cooperative activation in the Frank-Starling relation. ACTA ACUST UNITED AC 2011; 136:469-82. [PMID: 20876361 PMCID: PMC2947055 DOI: 10.1085/jgp.201010502] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cardiac sarcomeres produce greater active force in response to stretch, forming the basis of the Frank-Starling mechanism of the heart. The purpose of this study was to provide the systematic understanding of length-dependent activation by investigating experimentally and mathematically how the thin filament "on-off" switching mechanism is involved in its regulation. Porcine left ventricular muscles were skinned, and force measurements were performed at short (1.9 µm) and long (2.3 µm) sarcomere lengths. We found that 3 mM MgADP increased Ca(2+) sensitivity of force and the rate of rise of active force, consistent with the increase in thin filament cooperative activation. MgADP attenuated length-dependent activation with and without thin filament reconstitution with the fast skeletal troponin complex (sTn). Conversely, 20 mM of inorganic phosphate (Pi) decreased Ca(2+) sensitivity of force and the rate of rise of active force, consistent with the decrease in thin filament cooperative activation. Pi enhanced length-dependent activation with and without sTn reconstitution. Linear regression analysis revealed that the magnitude of length-dependent activation was inversely correlated with the rate of rise of active force. These results were quantitatively simulated by a model that incorporates the Ca(2+)-dependent on-off switching of the thin filament state and interfilament lattice spacing modulation. Our model analysis revealed that the cooperativity of the thin filament on-off switching, but not the Ca(2+)-binding ability, determines the magnitude of the Frank-Starling effect. These findings demonstrate that the Frank-Starling relation is strongly influenced by thin filament cooperative activation.
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Affiliation(s)
- Takako Terui
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
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Muraoka R, Nakano K, Kurihara S, Yamada K, Kawakami T. Immunohistochemical expression of heat shock proteins in the mouse periodontal tissues due to orthodontic mechanical stress. Eur J Med Res 2011; 15:475-82. [PMID: 21159572 PMCID: PMC3352656 DOI: 10.1186/2047-783x-15-11-475] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The histopathology of periodontal ligament of the mouse subjected to mechanical stress was studied. Immunohistochemical expressions of HSP27 and pHSP27 were examined. Experimental animals using the maxillary molars of ddY mouse by Waldo method were used in the study. A separator was inserted to induce mechanical stress. After 10 minutes, 20 minutes, 1 hour, 3 hours, 9 hours and 24 hours, the regional tissues were extracted, fixed in 4% paraformaldehyde and 0.05 M phosphate-buffered fixative solution. Paraffin sections were made for immunohistochemistry using HSP27 and p-HSP27. In the control group, the periodontal ligament fibroblasts expressed low HSP27 and p-HSP27. However, in the experimental group, periodontal ligament fibroblasts expressed HSP27 10 minutes after mechanical load application in the tension side. The strongest expression was detected 9 hours after inducing mechanical load. p-HSP27 was also expressed in a time-dependent manner though weaker than HSP27. The findings suggest that HSP27 and p-HSP27 were expressed for the maintenance of homeostasis of periodontal ligament by the activation of periodontal ligament fibroblasts on the tension side. It also suggests that these proteins act as molecular chaperones for osteoblast activation and maintenance of homeostasis.
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Affiliation(s)
- R Muraoka
- Hard Tissue Pathology Unit, Matsumoto Dental University, Graduate School of Oral Medicine, 1780 Hirooka-Gobara, Shiojiri, 399-0781 Japan.
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Fukuda N, Terui T, Ishiwata S, Kurihara S. Titin-based regulations of diastolic and systolic functions of mammalian cardiac muscle. J Mol Cell Cardiol 2010; 48:876-81. [DOI: 10.1016/j.yjmcc.2009.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/16/2009] [Accepted: 11/19/2009] [Indexed: 10/20/2022]
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Mizuno J, Morita S, Otsuji M, Hanaoka K, Kurihara S. [Evaluation of cardiac and myocardial inotropism and lusitropism using half-logistic curve-fitting]. Masui 2010; 59:422-431. [PMID: 20420127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Half-logistic (h-L) function, which is half of the sigmoidal, logistic function with a boundary at the inflection point, curve-fits the isovolumic relaxation left ventricular (LV) pressure curve from the minimum of the first order time derivative of pressure (dP/dt(min)), and the myocardial isometric relaxation tension curve from the minimum of the first order time derivative of tension (dF/dt(min)) superior to the conventional mono-exponential function. Recently, we found that h-L function could curve-fit the other partial curves. The isovolumic LV pressure curve in the excised, cross-circulated canine heart, was divided into four distinct phases with boundaries set at the maximum of dP/dt (dP/dt(max)), peak LV pressure, dP/dt(min), and LV end-diastolic pressure (LVEDP) resulting in the first phase from the point corresponding to QR on the electrocardiogram to dP/dt(max); the second phase from dP/dt(max) to the peak LV pressure; the third phase from the peak LV pressure to dP/dt(min); and the fourth phase from dP/dt(min) to LVEDP. Similarly, the isometric twitch tension curves in the mouse LV and rabbit right ventricular (RV) papillary muscles were divided into four distinct phases with boundaries set at the maximum of dF/dt (dF/dt(max)), peak tension, dF/dt(min), and resting tension resulting in the first phase from the point corresponding to twitch stimulation to dF/dt(max); the second phase from dF/dt(max) to the peak tension; the third phase from the peak tension to dF/dt(min); and the fourth phase from dF/dt(min) to resting tension. The h-L correlation coefficient (r) values for the sequential curves were larger than the m-E r values, respectively, and the h-L residual mean squares (RMS) were smaller than the m-E RMS values, respectively. The h-L time constants are indices which quantify cardiac and myocardial inotropism and lusitropism more accurately. We consider that the h-L approach also applies for evaluation of the isovolumic contraction phase and the isovolumic relaxation phase in the beating hearts.
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Affiliation(s)
- Ju Mizuno
- Department of Anesthesiology, Teikyo University School of Medicine, Tokyo 173-8605
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Komukai K, O-Uchi J, Morimoto S, Kawai M, Hongo K, Yoshimura M, Kurihara S. Role of Ca(2+)/calmodulin-dependent protein kinase II in the regulation of the cardiac L-type Ca(2+) current during endothelin-1 stimulation. Am J Physiol Heart Circ Physiol 2010; 298:H1902-7. [PMID: 20304814 DOI: 10.1152/ajpheart.01141.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelin-1 (ET-1) shows a positive inotropic effect on cardiac muscle. Although the L-type Ca(2+) current (I(Ca)) is one of the important determinants of cardiac excitation-contraction coupling, the effect of ET-1 on the I(Ca) is not always clear. The controversial results appear to be due to different patch-clamp methods. The present study measured the effect of ET-1 on the I(Ca) of rat ventricular myocytes using the perforated patch-clamp technique. The holding potential was set to -40 mV, and depolarization was applied every 10 s. ET-1 (10 nM) increased the I(Ca) in a monophasic manner. The current reached a steady state 15 min after the application of ET-1, when the measurement was done. Endothelin receptor subtype expression was also investigated using Western immunoblotting. ET(A)-receptor protein was expressed, but ET(B)-receptor protein was not expressed, in the cell membranes of rat ventricular myocytes. The effect of ET-1 on the I(Ca) was inhibited by a selective ET(A)-receptor antagonist, BQ-123, but not by a selective ET(B)-receptor antagonist, BQ-788. The effect was inhibited by protein kinase C (PKC) inhibitor chelerythrine and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93, but not by its inactive analog KN-92. The effect of ET-1 was also blocked by another CaMKII inhibitor, autocamtide-2-related inhibitory peptide. These results suggest that ET-1 increases the I(Ca) via the ET(A)-receptor-PKC-CaMKII pathway.
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Affiliation(s)
- Kimiaki Komukai
- Division of Cardiology, The Jikei Univ. School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461 Japan.
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Hata M, Ogino I, Omura M, Koike I, Kurihara S, Tayama Y, Odagiri K, Minagawa Y, Inoue T. Radiation Therapy for Primary Mucosa-associated Lymphoid Tissue (MALT) Lymphoma of the Orbit. Int J Radiat Oncol Biol Phys 2009. [DOI: 10.1016/j.ijrobp.2009.07.1104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Hama T, Yuza Y, Saito Y, O-uchi J, Kondo S, Okabe M, Yamada H, Kato T, Moriyama H, Kurihara S, Urashima M. Prognostic significance of epidermal growth factor receptor phosphorylation and mutation in head and neck squamous cell carcinoma. Oncologist 2009; 14:900-8. [PMID: 19726454 DOI: 10.1634/theoncologist.2009-0058] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The molecular status of the epidermal growth factor receptor (EGFR) has not been as well studied in head and neck squamous cell carcinoma (HNSCC) as in lung cancer. We examined the frequencies of EGFR mutations as well as the expression/phosphorylation status of the EGFR protein in HNSCC patients. Moreover, we tried to elucidate associations between EGFR molecular status and patient characteristics and disease-free survival. In this prospective cohort study, clinical data and samples were obtained from 82 consecutive patients who had not been treated with EGFR molecular targeting therapy. Full-length EGFR was sequenced, and expression and phosphorylation of the EGFR protein were measured by Western blotting. Four novel mutations (E709K, V765G, Ins770G, and G1022S) and one mutation well-known in lung cancer (L858R) were identified in six HNSCC samples (7%), but we could not find any mutations in the extracellular domain of EGFR, such as EGFRvIII, in this study. E709K and Ins770G as well as L858R appear to be functional mutations based on the use of Ba/F3 cells. In terms of patient characteristics, the number of metastatic lymph nodes and node stage were associated with phosphorylation of EGFR. No patients with EGFR mutations relapsed during the study period. Excluding mutated cases, patients whose tumor samples showed phosphorylated EGFR relapsed significantly earlier than those without phosphorylated EGFR. This finding was still significant after adjusting for mutation and overexpression of EGFR protein using the Cox proportional hazard model. In conclusion, phosphorylated EGFR without mutations may be a marker of poor prognosis in patients with HNSCC.
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Affiliation(s)
- Takanori Hama
- Division of Molecular Epidemiology, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
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Toshima H, Kimura N, Kurihara S. P1.31 Influence of smoking on the human autonomic nervous system. Auton Neurosci 2009. [DOI: 10.1016/j.autneu.2009.05.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Toshima H, Sugihara H, Hamano H, Sato M, Yamamoto M, Yamazaki S, Yamada Y, Taki M, Izumi SI, Hoshi K, Fusegawa Y, Satoh K, Ozaki Y, Kurihara S. Spontaneous platelet aggregation in normal subject assessed by a laser light scattering method: An attempt at standardization. Platelets 2009; 19:293-9. [DOI: 10.1080/09537100701883457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Mizuno J, Morita S, Otsuji M, Arita H, Hanaoka K, Akins RE, Hirano S, Kusakari Y, Kurihara S. Half-logistic time constants as inotropic and lusitropic indices for four sequential phases of isometric tension curves in isolated rabbit and mouse papillary muscles. Int Heart J 2009; 50:389-404. [PMID: 19506342 DOI: 10.1536/ihj.50.389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The waveforms of myocardial tension and left ventricular (LV) pressure curves are useful for evaluating myocardial and LV performance, and especially for inotropism and lusitropism. Recently, we found that half-logistic (h-L) functions provide better fits for the two partial rising and two partial falling phases of the isovolumic LV pressure curve compared to mono-exponential (m-E) functions, and that the h-L time constants for the four sequential phases are superior inotropic and lusitropic indices compared to the m-E time constants. In the present study, we tested the hypothesis that the four sequential phases of the isometric tension curves in mammalian cardiac muscles could be curve-fitted accurately using h-L functions. The h-L and m-E curve-fits were compared for the four phases of the isometric twitch tension curves in 7 isolated rabbit right ventricular and 15 isolated mouse LV papillary muscles. The isometric tension curves were evaluated in the four temporal phases: from the beginning of twitch stimulation to the maximum of the first order time derivative of tension (dF/dt(max)) (Phase I), from dF/dt(max) to the peak tension (Phase II), from the peak tension to the minimum of the first order time derivative of tension (dF/dt(min)) (Phase III), and from dF/dt(min) to the resting tension (Phase IV). The mean h-L correlation coefficients (r) of 0.9958, 0.9996, 0.9995, and 0.9999 in rabbit and 0.9950, 0.9996, 0.9994, and 0.9997 in mouse for Phases I, II, III, and IV, respectively, were higher than the respective m-E r-values (P < 0.001). The h-L function quantifies the amplitudes and time courses of the two partial rising and two partial falling phases of the isometric tension curve, and the h-L time constants for the four partial phases serve as accurate and useful indices for estimation of inotropic and lusitropic effects.
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Affiliation(s)
- Ju Mizuno
- Department of Anesthesiology, Teikyo University School of Medicine, Tokyo, Japan
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Matsuba D, Terui T, O-Uchi J, Tanaka H, Ojima T, Ohtsuki I, Ishiwata S, Kurihara S, Fukuda N. Protein kinase A-dependent modulation of Ca 2+sensitivity in cardiac and fast skeletal muscles after reconstitution with cardiac troponin. J Biophys Biochem Cytol 2009. [DOI: 10.1083/jcb1855oia12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Matsuba D, Terui T, O-Uchi J, Tanaka H, Ojima T, Ohtsuki I, Ishiwata S, Kurihara S, Fukuda N. Protein kinase A-dependent modulation of Ca2+ sensitivity in cardiac and fast skeletal muscles after reconstitution with cardiac troponin. ACTA ACUST UNITED AC 2009; 133:571-81. [PMID: 19433622 PMCID: PMC2713144 DOI: 10.1085/jgp.200910206] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Protein kinase A (PKA)-dependent phosphorylation of troponin (Tn)I represents a major physiological mechanism during β-adrenergic stimulation in myocardium for the reduction of myofibrillar Ca2+ sensitivity via weakening of the interaction with TnC. By taking advantage of thin filament reconstitution, we directly investigated whether or not PKA-dependent phosphorylation of cardiac TnI (cTnI) decreases Ca2+ sensitivity in different types of muscle: cardiac (porcine ventricular) and fast skeletal (rabbit psoas) muscles. PKA enhanced phosphorylation of cTnI at Ser23/24 in skinned cardiac muscle and decreased Ca2+ sensitivity, of which the effects were confirmed after reconstitution with the cardiac Tn complex (cTn) or the hybrid Tn complex (designated as PCRF; fast skeletal TnT with cTnI and cTnC). Reconstitution of cardiac muscle with the fast skeletal Tn complex (sTn) not only increased Ca2+ sensitivity, but also abolished the Ca2+-desensitizing effect of PKA, supporting the view that the phosphorylation of cTnI, but not that of other myofibrillar proteins, such as myosin-binding protein C, primarily underlies the PKA-induced Ca2+ desensitization in cardiac muscle. Reconstitution of fast skeletal muscle with cTn decreased Ca2+ sensitivity, and PKA further decreased Ca2+ sensitivity, which was almost completely restored to the original level upon subsequent reconstitution with sTn. The essentially same result was obtained when fast skeletal muscle was reconstituted with PCRF. It is therefore suggested that the PKA-dependent phosphorylation or dephosphorylation of cTnI universally modulates Ca2+ sensitivity associated with cTnC in the striated muscle sarcomere, independent of the TnT isoform.
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Affiliation(s)
- Douchi Matsuba
- Department of Cell Physiology, Jikei University School of Medicine, Tokyo 105-8461, Japan
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Yajima A, Akizawa T, Tsukamoto Y, Kurihara S, Ito A. Impact of cinacalcet hydrochloride on bone histology in patients with secondary hyperparathyroidism. Ther Apher Dial 2009; 12 Suppl 1:S38-43. [PMID: 19032526 DOI: 10.1111/j.1744-9987.2008.00630.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Serum parathyroid hormone (PTH) levels are effectively decreased by cinacalcet hydrochloride (HCl) in patients with secondary hyperparathyroidism. We assessed the impact of cinacalcet HCl on bone histology in these patients. Four hemodialysis patients with secondary hyperparathyroidism (intact PTH > or = 300 pg/mL) were treated with cinacalcet HCl with low-doses of vitamin D sterols as well as calcium-based phosphate binders for 52 weeks. Patients 1, 2, 3 and 4 were aged 55, 65, 61 and 70 years old, and the duration of hemodialysis in the patients was 84, 176, 125 and 216 months, respectively. Serum intact PTH, serum bone metabolism markers and bone histomorphometric parameters were determined before and after 52 weeks of the treatment. Serum intact PTH decreased from 1110, 880, 330 and 980 pg/mL to 233, 80, 88 and 116 pg/mL, respectively, in the four patients after 52 weeks of treatment with cinacalcet HCl. Serum levels of bone metabolism markers and all of the histomorphometric resorption parameters decreased in these patients. In particular, fibrosis volume decreased to 0% in all of the patients. Static formation parameters, including osteoblast surface and osteoid-related parameters, all decreased after the treatment, indicating an increase of mineralized bone volume during the treatment. Dynamic parameters except for activation frequency decreased after the treatment, indicating significant suppression of bone turnover. Cinacalcet HCl with low-doses of vitamin D sterols suppressed serum PTH with no significant changes of serum calcium levels. In addition, long-term administration of cinacalcet HCl improved hyperparathyroid bone diseases in patients with secondary hyperparathyroidism.
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Affiliation(s)
- Aiji Yajima
- Department of Nephrology, Towa Hospital, Tokyo, Japan.
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Terui T, Shimamoto Y, Sodnomtseren M, Yamane M, Ohtsuki I, Ishiwata S, Kurihara S, Fukuda N. Role of Thin Filament Cooperative Activation in Length-dependent Activation in Skinned Porcine Ventricular Muscle. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.1936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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O-Uchi J, Komukai K, Morimoto S, Hongo K, Kurihara S. Cardiac Alpha1a-adrenoceptor Stimulation Inhibits L-type Ca2+ Current In The Presence Of Beta-adrenoceptor Stimulation Through Tyrosine Kinase. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.1931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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dos Remedios CG, Yamane M, Hughes J, Stefani M, Fukuda N, Kurihara S, Steenman M, Ishiwata S. SPOC: A Functional Assay of Failing and Non-Failing Human Cardiomyocytes. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.1941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Fukuda N, Matsuba D, Terui T, O-Uchi J, Tanaka H, Ojima T, Ohtsuki I, Ishiwata S, Kurihara S. Protein Kinase A-based Modulation Of Ca2+ Sensitivity In Skinned Skeletal Muscle Fibers Reconstituted With Cardiac Troponin. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.2583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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dos Remedios CG, Yamane M, Robinson J, Hughes J, Stefani M, Fukuda N, Kurihara S, Steenman M, Ishiwata S. Spontaneous Oscillatory Contraction: A Functional Assay of Contractile Function of Human Heart Samples Stored at −190°C. Heart Lung Circ 2009. [DOI: 10.1016/j.hlc.2009.05.476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mizuno J, Morita S, Araki J, Otsuji M, Hanaoka K, Kurihara S. [Curve-fit with hybrid logistic function for intracellular calcium transient]. Masui 2009; 58:67-76. [PMID: 19175017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
As the left ventricular (LV) pressure curve and myocardial tension curve in heart are composed of contraction and relaxation processes, we have found that hybrid logistic (HL) function calculated as the difference between two logistic functions curve-fits better the isovolumic LV pressure curve and the isometric twitch tension curve than the conventional polynomial exponential and sinusoidal functions. Increase and decrease in intracellular Ca2+ concentration regulate myocardial contraction and relaxation. Recently, we reported that intracellular Ca2+ transient (CaT) curves measured using the calcium-sensitive bioluminescent protein, aequorin, were better curve-fitted by HL function compared to the polynomial exponential function in the isolated rabbit RV and mouse LV papillary muscles. We speculate that the first logistic component curve of HL fit represents the concentration of the Ca2+ inflow into the cytoplasmic space, the concentration of Ca2+ released from sarcoplasmic reticulum (SR), the concentration of Ca2+ binding to troponin C (TnC), and the attached number of cross-bridge (CB) and their time courses, and that the second logistic component curve of HL fit represents the concentration of Ca2+ sequestered into SR, the concentration of Ca2+ removal from the cytoplasmic space, the concentration of Ca2+ released from TnC, and the detached number of CB and their time courses. This HL approach for CaT curve may provide a more useful model for investigating Ca2+ handling, Ca(2+) -TnC interaction, and CB cycling.
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Affiliation(s)
- Ju Mizuno
- Department of Anesthesiology, Teikyo University School of Medicine, Tokyo 173-8605
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