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Yamasaki T, Kakita K, Pak M, Hattori T. Quantitative comparison of the isolation lesions between conventional- and larger-sized visually guided laser balloon ablation. J Interv Card Electrophysiol 2024:10.1007/s10840-024-01738-6. [PMID: 38427180 DOI: 10.1007/s10840-024-01738-6] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/04/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND The importance of a wider circumferential isolation of the pulmonary veins (PV), which includes a large portion of the left atrial posterior wall (LAPW), has been suggested in several studies. However, the extended isolation area using a larger inflated visually guided laser balloon (VGLB) ablation remains to be elucidated. METHODS Seventy-eight patients with atrial fibrillation (AF) who underwent VGLB ablation were enrolled in this prospective study. An electroanatomic map of the left atrium was obtained before and after PV isolation (PVI) using a conventional-sized VGLB. The isolation areas were extended by the largest-sized VGLB ablation and remapped in the same manner. After the ablation, isolation areas were calculated with CARTO-3 system. The one-year atrial arrhythmia (Ata) recurrence was assessed. RESULTS: The largest-sized VGLB ablation yielded statistically greater areas of isolation in left-sided PV antrum (PVA) (11.5 ± 2.3 cm2 vs. 15.9 ± 3.5 cm2, P < .001) and right-sided PVA (14.2 ± 3.3 cm2 vs. 20.6 ± 4.4 cm2, P < .001) than the conventional-sized VGLB. Further, non-ablated LAPW (12.3 ± 4.4 cm2 vs. 7.8 ± 3.9 cm2, P < .001) was significantly reduced after largest-sized VGLB ablation, compared to the conventional-sized VGLB ablation. The one-year Ata freedom was 83.7% in patients with paroxysmal AF and 96.4% in those with persistent AF. CONCLUSION The largest-sized VGLB ablation technique can create a significantly wider isolation area of PVA and debulk a large amount of LAPW than the conventional-sized VGLB ablation. The one-year outcome was similarly high in paroxysmal and persistent AF.
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Affiliation(s)
- Takashi Yamasaki
- Arrhythmia Care Center, Koseikai Takeda Hospital, 841-5 Higashi Shiokoji-Cho, Shiokoji-Dori Nishinotoin-Higashiiru, Shimogyo-Ku, Kyoto, 600-8558, Japan.
| | - Ken Kakita
- Arrhythmia Care Center, Koseikai Takeda Hospital, 841-5 Higashi Shiokoji-Cho, Shiokoji-Dori Nishinotoin-Higashiiru, Shimogyo-Ku, Kyoto, 600-8558, Japan
| | - Misun Pak
- Arrhythmia Care Center, Koseikai Takeda Hospital, 841-5 Higashi Shiokoji-Cho, Shiokoji-Dori Nishinotoin-Higashiiru, Shimogyo-Ku, Kyoto, 600-8558, Japan
| | - Tetsuhisa Hattori
- Arrhythmia Care Center, Koseikai Takeda Hospital, 841-5 Higashi Shiokoji-Cho, Shiokoji-Dori Nishinotoin-Higashiiru, Shimogyo-Ku, Kyoto, 600-8558, Japan
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Kitai T, Pak M. Reply: Elevated Filling Pressures: Identifying Patients With the Use of Atrial Expansion Index and Atrial Strain. JACC Cardiovasc Imaging 2022; 15:2015-2016. [PMID: 36357146 DOI: 10.1016/j.jcmg.2022.08.013] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022]
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Tsujisaka Y, Kaji S, Kim K, Pak M, Sasaki Y, Kitai T, Kobori A, Furukawa Y. Mechanism of improvement in atrial functional mitral regurgitation after catheter ablation for atrial fibrillation: Three-dimensional analysis using multislice computed tomography. J Card Surg 2021; 37:314-321. [PMID: 34734658 DOI: 10.1111/jocs.16120] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 10/17/2021] [Accepted: 10/18/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several factors associated with atrial functional mitral regurgitation development have been reported; however, geometric changes in the mitral apparatus after catheter ablation for atrial fibrillation have not been sufficiently investigated. This study aimed to clarify what determines improvements in atrial functional mitral regurgitation after sinus rhythm restoration in patients who underwent catheter ablation for atrial fibrillation by using multislice computed tomography. METHODS We analysed volumetric multislice computed tomography images of 44 atrial fibrillation patients with significant atrial functional mitral regurgitation (moderate or worse) before and after catheter ablation. We measured the three-dimensional geometry of the mitral apparatus including the mitral annular area and interpapillary muscle distance. We calculated the differences before and after catheter ablation (Δmitral annular area, Δinterpapillary muscle distance) and assessed mitral regurgitation severity based on the mitral regurgitant jet area and its changes before and after catheter ablation (Δjet area) using transthoracic echocardiography. RESULTS After catheter ablation, the jet area was significantly decreased. The left ventricular ejection fraction was significantly increased and the left ventricular volume had a decreasing trend. The Δjet area was significantly correlated with the Δinterpapillary muscle distance (r = .43; p = .004). The Δinterpapillary muscle distance was the strongest determinant of improvements in atrial functional mitral regurgitation severity (p = .026). CONCLUSIONS Decreased interpapillary muscle distance was strongly associated with improvements in atrial functional mitral regurgitation. Amelioration of left ventricular dysfunction by sinus rhythm restoration might be related to improvements in atrial functional mitral regurgitation after catheter ablation.
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Affiliation(s)
- Yuta Tsujisaka
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Shuichiro Kaji
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Kitae Kim
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Misun Pak
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasuhiro Sasaki
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Takeshi Kitai
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Atsushi Kobori
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yutaka Furukawa
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
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Kobori A, Sasaki Y, Pak M, Ishikura M, Murai R, Okada T, Toyota T, Taniguchi T, Kim K, Ehara N, Kinoshita M, Kihara Y, Furukawa Y. Comparison of Cryoballoon and Contact Force-Sensing Radiofrequency Ablation for Persistent Atrial Fibrillation in Clinical Practice. Circ J 2021; 86:290-298. [PMID: 34565782 DOI: 10.1253/circj.cj-21-0608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Outcomes of cryoballoon ablation for persistent atrial fibrillation (AF) are unclear, especially in Japanese patients, so the effectiveness and safety of cryoballoon ablation in clinical practice were retrospectively compared with those of contact force-sensing radiofrequency (CFRF) ablation including the high-power protocol.Methods and Results:Consecutive patients with persistent AF were reviewed, and 253 and 265 patients who underwent cryoballoon and CFRF ablation, respectively, were enrolled. The primary endpoint was atrial arrhythmia recurrence. The secondary endpoints were periprocedural complications and repeat ablation. The rate of additional left atrial (LA) ablation after pulmonary vein isolation (PVI) was similar between groups (68.8% cryoballoon vs. 74.0% CFRF, P=0.19). Freedom from atrial arrhythmia recurrence was comparable between groups over a follow-up of 25.5±12.5 months (72.3% cryoballoon vs. 69.8% CFRF; adjusted hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.59-1.21, P=0.36). Outcomes were similar in the subgroups of PVI alone and PVI plus additional LA ablation. LA posterior wall isolation, absence of defragmentation, and low creatine clearance, but not catheter selection, were associated with the primary endpoint. Periprocedural complications (adjusted HR 0.73, 95% CI 0.34-1.54, P=0.41) and repeat ablation (adjusted HR 1.11, 95% CI 0.71-1.74, P=0.64) were similar for both procedures. CONCLUSIONS Cryoballoon ablation for persistent AF in Japanese clinical practice had acceptable outcomes comparable to those of advanced CFRF ablation.
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Affiliation(s)
- Atsushi Kobori
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Yasuhiro Sasaki
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Misun Pak
- Department of Cardiology, Kobe City Medical Center General Hospital
| | | | - Ryosuke Murai
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Taiji Okada
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Toshiaki Toyota
- Department of Cardiology, Kobe City Medical Center General Hospital
| | | | - Kitae Kim
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Natsuhiko Ehara
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Makoto Kinoshita
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Yasuki Kihara
- Department of Cardiology, Kobe City Medical Center General Hospital
| | - Yutaka Furukawa
- Department of Cardiology, Kobe City Medical Center General Hospital
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Kobori A, Sasaki Y, Pak M, Okada T, Toyota T, Kim K, Kitai T, Ehara N, Kinoshita M, Kaji S, Kihara Y, Furukawa Y. Early experiences with three types of balloon-based ablation catheters in patients with paroxysmal atrial fibrillation. Heart Rhythm O2 2021; 2:223-230. [PMID: 34337572 PMCID: PMC8322794 DOI: 10.1016/j.hroo.2021.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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] [Indexed: 11/24/2022] Open
Abstract
Background Although balloon-based ablation catheters are expected to improve the feasibility and quality of pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF), they must be introduced to physicians in the proper setting to ensure their correct usage. Objective To identify the optimal clinical settings for learning the techniques for 3 balloon-based ablation catheters (Cryoballoon, Hotballoon, and Laserballoon). Methods We introduced 3 balloon catheters in 50 consecutive patients with paroxysmal AF each during the introduction periods. Clinical parameters were compared among the groups and between these groups and their steady-state controls. Results The completion rate of PVI by sole balloon procedures was 56% with the Hotballoon catheter, which was lower than those of the Cryoballoon and Laserballoon catheters (each 88%). Radiofrequency touch-up was most frequently required at the bottom aspect of the inferior pulmonary veins (PVs) in the Cryoballoon group and at the anterior aspect of the superior PVs in the Hotballoon and Laserballoon groups. The Laserballoon catheter had the longest average PVI procedural time (89.2 ± 40 vs 58.4 ± 22 minutes for Hotballoon, 65.1 ± 25 minutes for Cryoballoon, P < .001), but the difference was ultimately removed by the learning curve. There was no significant difference in the major complication or recurrence-free survival rates among the catheter types. Conclusions All 3 balloon-based catheter types allowed feasibility and quality for PVI, even during the learning period. To introduce these new catheters without complications, an experiences of 20 cases with specific clinical settings should be met for each catheter type.
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Affiliation(s)
- Atsushi Kobori
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasuhiro Sasaki
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Misun Pak
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Taiji Okada
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Toshiaki Toyota
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Kitae Kim
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Takeshi Kitai
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Natsuhiko Ehara
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Makoto Kinoshita
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Shuichiro Kaji
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasuki Kihara
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yutaka Furukawa
- Department of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
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Pak M, Hara M, Miura S, Furuya M, Tamaki M, Okada T, Watanabe N, Endo A, Tanabe K. Delirium is associated with high mortality in older adult patients with acute decompensated heart failure. BMC Geriatr 2020; 20:524. [PMID: 33272204 PMCID: PMC7713169 DOI: 10.1186/s12877-020-01928-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 08/02/2020] [Accepted: 11/23/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Delirium is associated with high mortality after cardiac surgery. However, evidence on the epidemiology of delirium in patients with acute decompensated heart failure (ADHF) is limited. This study aimed to assess the incidence and prognostic impact of delirium in patients with ADHF. METHODS This single-center prospective observational study enrolled 132 consecutive patients with ADHF. We utilized the Diagnostic and Statistical Manual of Mental Disorders, fifth edition and classified the patients into two groups according to the presence or absence of delirium. The primary endpoint was 90-day all-cause mortality. The prognostic impact and risk factors of delirium were evaluated using multivariable Cox and logistic regression analyses, respectively. RESULTS The median patient age was 83 (interquartile range, 75-87) years. Approximately 51.5% were men. Delirium occurred in 36 (27.3%) patients, and hyperactive delirium was the most frequent type (86.1%). The 90-day all-cause mortality was higher in the patients with delirium than in those without (21.6% versus 3.9%, log-rank p = 0.002). Delirium was associated with higher mortality with an adjusted hazard ratio of 6.8 (95% confidence interval, 1.1-42.6, p = 0.042). The risk factors associated with delirium included advanced age, male sex, higher clinical frailty scale score, and dementia. CONCLUSIONS Delirium was associated with a higher 90-day all-cause mortality in the older adult patients with ADHF. Hyperactive delirium was the most common subtype.
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Affiliation(s)
- Misun Pak
- Department of Cardiology, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan.
| | - Masahiko Hara
- Center for Community-Based Healthcare Research and Education, Shimane University, Izumo, Japan.,Department of Clinical Investigation, Japan Society of Clinical Research, Osaka, Japan
| | - Shoko Miura
- Department of Psychiatry, Shimane University Faculty of Medicine, Izumo, Japan
| | - Motohide Furuya
- Department of Psychiatry, Shimane University Faculty of Medicine, Izumo, Japan
| | - Masatake Tamaki
- Department of Clinical Investigation, Japan Society of Clinical Research, Osaka, Japan.,Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Fukushima, Japan
| | - Taiji Okada
- Department of Cardiology, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan
| | - Nobuhide Watanabe
- Department of Cardiology, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan
| | - Akihiro Endo
- Department of Cardiology, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan
| | - Kazuaki Tanabe
- Department of Cardiology, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan
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Pak M, Kobori A, Shizuta S, Sasaki Y, Toyota T, Yoshizawa T, Inoue K, Kaitani K, Kurotobi T, Morishima I, Kusano K, Kimura T, Furukawa Y. The impact of catheter ablation for patients with asymptomatic atrial fibrillation: subanalysis of kansai plus atrial fibrillation (kpaf) registry. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/14/2022] Open
Abstract
Abstract
Background
Catheter ablation (CA) of atrial fibrillation (AF) for symptomatic patients improves the quality of life and prognosis of patients with heart failure. However, the impact of CA for asymptomatic patients is still controversial.
Purpose
We aimed to investigate the clinical outcomes of CA of AF for asymptomatic patients compared to those for symptomatic patients.
Methods
A total of 5,013 patients from the Kansai Plus Atrial Fibrillation (KPAF) Registry who underwent CA were screened. The patients were divided into three groups by type of AF; paroxysmal (PAF), persistent (PEAF) and long standing (LSAF) and the patients in each type of AF were divided into two groups: asymptomatic and symptomatic. The primary endpoint was recurrent supraventricular tachyarrhythmias lasting for more than 30 seconds during follow-up 4 years after CA. The secondary endpoint was a composite of cardiovascular, cerebral, and gastrointestinal events during follow-up 4 years after CA. The incidence of complications related to CA between asymptomatic and symptomatic patients was also evaluated. Kaplan–Meier analysis was employed to estimate the primary and secondary endpoints. The statistical differences in primary and secondary endpoints between asymptomatic and symptomatic patients were evaluated using a log–rank test. The impact of symptom due to AF on the primary and secondary endpoint was evaluated using a Cox hazard analysis. The difference in incidence of complications between asymptomatic and symptomatic patients was evaluated using a chi–square test.
Results
In this study population, PAF was the most frequent at 64.4%, followed by PEAF (22.7%) and LSAF (13.0%). There were some significant differences in the baseline characteristics between asymptomatic and symptomatic patients in each type of AF. The proportion of male was significantly higher in asymptomatic patients than symptomatic patients in PAF (81.2% versus 67.2%, p<0.001) and PEAF (86.4% versus 74.3%, p<0.001). Left atrial diameter was larger in asymptomatic patients than symptomatic patients only in PAF (40±6mm versus 38±6mm, p<0.001). In all types of AF, there was no significant difference in primary endpoint between asymptomatic and symptomatic patients as follows: 37.5% versus 40.6% (p=0.6) in PAF, 45.2% versus 55.1% (p=0.09) in PEAF and 59.3% versus 63.6% (p=1.0) in LSAF. There was also no significant difference in secondary endpoint between asymptomatic and symptomatic patients: 7.1% versus 6.8% (p=0.7) in PAF, 5.4% versus 8.7% (p=0.3) in PEAF and 4.4% versus 5.1% (p=0.5) in LSAF. In a Cox hazard analysis, the symptom did not affect both of the primary and secondary endpoints in each type of AF. In regard to the incidence of complications related to CA, there was no significant difference between asymptomatic and symptomatic patients in each type of AF.
Conclusion
CA of AF for asymptomatic patients can be safe and can lead to equivalent outcomes as well as symptomatic patients.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- M Pak
- Kobe City Medical Center General Hospital, Kobe, Japan
| | - A Kobori
- Kobe City Medical Center General Hospital, Kobe, Japan
| | - S Shizuta
- Kyoto University Graduate School of Medicine, Cardiovascular Medicine, Kyoto, Japan
| | - Y Sasaki
- Kobe City Medical Center General Hospital, Kobe, Japan
| | - T Toyota
- Kobe City Medical Center General Hospital, Kobe, Japan
| | - T Yoshizawa
- Kyoto University Graduate School of Medicine, Cardiovascular Medicine, Kyoto, Japan
| | - K Inoue
- Sakurabashi-Watanabe Hospital, Cardiovascular center, Osaka, Japan
| | - K Kaitani
- Japanese Red Cross Otsu Hospital, Otsu, Japan
| | - T Kurotobi
- Namba Kurotobi Heart Clinic, Osaka, Japan
| | | | - K Kusano
- National Cerebral & Cardiovascular Center, Suita, Japan
| | - T Kimura
- Kyoto University Graduate School of Medicine, Cardiovascular Medicine, Kyoto, Japan
| | - Y Furukawa
- Kobe City Medical Center General Hospital, Kobe, Japan
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Kim K, Kitai T, Kaji S, Pak M, Toyota T, Sasaki Y, Ehara N, Kobori A, Kinoshita M, Furukawa Y. Outcomes and predictors of cardiac events in medically treated patients with atrial functional mitral regurgitation. Int J Cardiol 2020; 316:195-202. [DOI: 10.1016/j.ijcard.2020.06.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/30/2020] [Accepted: 06/24/2020] [Indexed: 12/31/2022]
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Endo A, Okada T, Kagawa Y, Sato H, Morita Y, Pak M, Ouchi T, Watanabe N, Yamaguchi K, Yoshitomi H, Tanabe K. P642What is the most important residual risk after achievement of appropriate low-density lipoprotein cholesterol lowering therapy in secondary prevention of Japanese patients? Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/13/2022] Open
Abstract
Abstract
Background
In secondary prevention of coronary artery disease, target value of low-density lipoprotein cholesterol (LDL-C) <100mg/dL with using statins is recommended as standard therapy in Japanese guideline. However, impact of residual risks after achievement of standard LDL-C lowering therapy was not fully examined. Furthermore, there is little information whether more strict management of LDL-C lowering is effective to prevent long-term cardiovascular events than standard management.
Purpose
The purpose of this study was to evaluate the relationship between residual risks after achievement of standard LDL-C lowering therapy and long-term coronary events in secondary prevention of Japanese patients.
Methods
From January 2007 to August 2018, 333 patients with previous percutaneous coronary intervention underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early phase of restenosis. We defined appropriate LDL-C lowering therapy as achieved LDL-C <100mg/dL with using statins. Patients whose achieved LDL-C was <100mg/dL with using statins were classified as Appropriate-group (n=139), and patients who were not using statins or whose achieved LDL-C was ≥100mg/dL were classified as Inappropriate-group (n=194). Endpoints of the study were recurrence of cardiac ischemia as acute coronary syndrome (recurrence-ACS) and any late coronary revascularization.
Results
During average 7.1 years follow-up, 195 patients (59%) underwent any late coronary revascularization. In 91 of those patients, clinical presentation of recurrence-ACS was observed. Kaplan-Meier curve analysis revealed that the incidence of recurrence-ACS and any late coronary revascularization were significantly lower in Appropriate-group than in Inappropriate-group (p=0.017 and p<0.001, respectively). In Appropriate-group, recurrence-ACS was significantly lower in patients with achieved LDL-C <70mg/dL than in those with LDL-C 70 to <100mg/dL (p=0.042), however, any late revascularization was not different between the two groups. On the other hand, in Inappropriate-group, recurrence-ACS was significantly lower in patients with using statins than in those without using statins (p=0.038), and any late revascularization was less frequent in patients with achieved LDL-C <100mg/dL than in those with LDL-C ≥100mg/dL (p=0.035). Moreover, multivariate analysis identified that only LDL-C was an independent predictor of recurrence-ACS in Appropriate-group (HR: 1.047, p=0.006), in contrast, LDL-C (HR: 1.008, p=0.020), using statins (HR: 0.555, p=0.034) and triglyceride (HR: 1.003, p=0.038) were independent predictors of recurrence-ACS in Inappropriate-group.
Conclusions
LDL-C was the most important residual risk of recurrence-ACS even after recommended standard therapy has been achieved. More strict management of LDL-C targeting to <70mg/dL should be considered in secondary prevention of Japanese patients.
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Affiliation(s)
- A Endo
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - T Okada
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - Y Kagawa
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - H Sato
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - Y Morita
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - M Pak
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - T Ouchi
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - N Watanabe
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | - K Yamaguchi
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
| | | | - K Tanabe
- Shimane University Faculty of Medicine, Division of Cardiology, Izumo, Japan
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Bezryadin A, Belkin A, Ilin E, Pak M, Colla EV, Hubler A. Large energy storage efficiency of the dielectric layer of graphene nanocapacitors. Nanotechnology 2017; 28:495401. [PMID: 29027908 DOI: 10.1088/1361-6528/aa935c] [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] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electric capacitors are commonly used in electronic circuits for the short-term storage of small amounts of energy. It is desirable however to use capacitors to store much larger energy amounts to replace rechargeable batteries. Unfortunately existing capacitors cannot store sufficient energy to be able to replace common electrochemical energy storage systems. Here we examine the energy storage capabilities of graphene nanocapacitors, which are tri-layer devices involving an Al film, Al2O3 dielectric layer, and a single layer of carbon atoms, i.e., graphene. This is a purely electronic capacitor and therefore it can function in a wide temperature interval. The capacitor shows a high dielectric breakdown electric field strength, of the order of 1000 kV mm-1 (i.e., 1 GV m-1), which is much larger than the table value of the Al2O3 dielectric strength. The corresponding energy density is 10-100 times larger than the energy density of a common electrolytic capacitor. Moreover, we discover that the amount of charge stored in the dielectric layer can be equal or can even exceed the amount of charge stored on the capacitor plates. The dielectric discharge current follows a power-law time dependence. We suggest a model to explain this behavior.
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Affiliation(s)
- A Bezryadin
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
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Pinarbasi A, Aksungar F, Arslan D, Kolay M, Pak M, Serteser M, Unsal I. SUN-P001: Metabolic and Mitochondrial Changes in an Intermittent Fasting Model in Humans. Clin Nutr 2017. [DOI: 10.1016/s0261-5614(17)30624-6] [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: 11/15/2022]
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Endo A, Okada T, Kagawa Y, Pak M, Ito S, Ouchi T, Watanabe N, Yamaguchi K, Yoshitomi H, Tanabe K. 5968Comparison of the low-density lipoprotein cholesterol target value and the preventive effect of statins in elderly patients and younger patients. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.5968] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Sakamoto T, Pak M, Ito S, Okada T, Kagawa Y, Nakamura T, Ouchi T, Watanabe N, Endo A, Yoshitomi H, Tanabe K. P5263Cutoff for left ventricular ejection fraction that will change from reduced to preserved or preserved to reduced in patients with heart failure. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5263] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pak M, Kagawa Y, Watanabe N, Imai K, Endo A, Tanabe K. Development of an iatrogenic aneurysm nine months after pacemaker implantation: Consideration of causes and treatment. J Cardiol Cases 2017; 16:89-92. [PMID: 30279805 DOI: 10.1016/j.jccase.2017.05.007] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/02/2017] [Accepted: 05/24/2017] [Indexed: 10/19/2022] Open
Abstract
Careful technique is required in pacemaker implantation to avoid serious iatrogenic complications. A 70-year-old woman on an anticoagulant agent underwent pacemaker implantation. Nine months after implantation, a 35-mm pulsatile mass appeared just near the cranial edge of the generator. An iatrogenic pseudoaneurysm was suspected because ultrasonography showed communication with the blood stream through tiny artery. The resected mass proved to be a pseudoaneurysm. This was a rare case of iatrogenic delayed pseudoaneurysm appearing nine months later. It is essential to keep in mind the risk of pseudoaneurysm after pacemaker implantation, especially when the patient takes anticoagulant agents. <Learning objective: Iatrogenic delayed pseudoaneurysm might develop after pacemaker implantation. It is essential to avoid risk factors for a pseudoaneurysm after pacemaker implantation when the patient is taking anticoagulant agents and to keep in mind careful follow-up even after discharge. Prospective measures such as suspension of antithrombotic agents, minimizing puncture attempts, and wound compression are also important.>.
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Affiliation(s)
- Misun Pak
- Department of Cardiology, Shimane University Faculty of Medicine, Shimane, Japan
| | - Yuzo Kagawa
- Department of Cardiology, Shimane University Faculty of Medicine, Shimane, Japan
| | - Nobuhide Watanabe
- Department of Cardiology, Shimane University Faculty of Medicine, Shimane, Japan
| | - Kensuke Imai
- Department of Cardiovascular Surgery, Shimane University Faculty of Medicine, Shimane, Japan
| | - Akihiro Endo
- Department of Cardiology, Shimane University Faculty of Medicine, Shimane, Japan
| | - Kazuaki Tanabe
- Department of Cardiology, Shimane University Faculty of Medicine, Shimane, Japan
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Denissenya M, Glozman L, Pak M. Erratum: Emergence of a newSU(4)symmetry in the baryon spectrum [Phys. Rev. D92, 074508 (2015)]. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.92.099902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Song X, Pak M, Chavez C, Liang M, Lu H, Blake-Haskins A, Robbins P, Jin X, Gupta A, Roskos L, Narwal R. 203 Population pharmacokinetics of MEDI4736, a fully human antiprogrammed death ligand 1 (PD-L1) monoclonal antibody, in patients with advanced solid tumors. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)30091-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pak M, Schröck M. Overlap quark propagator in coulomb gauge QCD and the interrelation of confinement and chiral symmetry breaking. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.91.074515] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pak M, Ito S, Takeda M, Watanabe N, Sato H, Ito S, Adachi T, Sugamori T, Endo A, Takahashi N, Yoshitomi H, Ishibashi Y, Tanabe K. A Case of Ascending Aortic Dissection and Rupture Caused by Giant Cell Arteritis. Int Heart J 2014; 55:555-9. [DOI: 10.1536/ihj.14-059] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Misun Pak
- Division of Cardiology, Shimane University Faculty of Medicine
| | - Shimpei Ito
- Division of Cardiology, Shimane University Faculty of Medicine
| | - Masaki Takeda
- Division of Cardiology, Shimane University Faculty of Medicine
| | | | - Hirotomo Sato
- Division of Cardiology, Shimane University Faculty of Medicine
| | - Saki Ito
- Division of Cardiology, Shimane University Faculty of Medicine
| | - Tomoko Adachi
- Division of Cardiology, Shimane University Faculty of Medicine
| | | | - Akihiro Endo
- Division of Cardiology, Shimane University Faculty of Medicine
| | | | - Hiroyuki Yoshitomi
- Department of Clinical Laboratory, Shimane University Faculty of Medicine
| | - Yutaka Ishibashi
- Department of Community Medicine Management, Shimane University Faculty of Medicine
| | - Kazuaki Tanabe
- Division of Cardiology, Shimane University Faculty of Medicine
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Ito S, Yoshitomi H, Pak M, Kawahara H, Oshima T, Ito S, Watanabe N, Sato H, Adachi T, Takeda M, Sugamori T, Takahashi N, Endo A, Ishibashi T, Tanabe K. Trousseau syndrome with nonbacterial thrombotic endocarditis in a patient with uterine cancer. Intern Med 2013; 52:1353-8. [PMID: 23774546 DOI: 10.2169/internalmedicine.52.9384] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This paper aims to describe the usefulness of transthoracic echocardiography in the follow-up of recurrent nonbacterial thrombotic endocarditis (NBTE) associated with neoplastic conditions. A 60-year-old woman with advanced uterine cancer developed recurrent areas of aseptic vegetation on the mitral valve along with cerebral, renal and splenic embolisms. Echocardiographic assessments revealed vegetation and thrombotic events on three occasions. In this case, transthoracic echocardiography was effective in following the decreased frequency of attachment of the NBTE vegetation to the mitral valve and reductions in the size of the area of vegetation following treatment with unfractionated heparin infusion, hysterectomy and chemotherapy.
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Affiliation(s)
- Saki Ito
- Division of Cardiology, Shimane University Faculty of Medicine, Japan.
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Appelmelk BJ, den Dunnen J, Driessen NN, Ummels R, Pak M, Nigou J, Larrouy-Maumus G, Gurcha SS, Movahedzadeh F, Geurtsen J, Brown EJ, Eysink Smeets MM, Besra GS, Willemsen PTJ, Lowary TL, van Kooyk Y, Maaskant JJ, Stoker NG, van der Ley P, Puzo G, Vandenbroucke-Grauls CMJE, Wieland CW, van der Poll T, Geijtenbeek TBH, van der Sar AM, Bitter W. The mannose cap of mycobacterial lipoarabinomannan does not dominate the Mycobacterium–host interaction. Cell Microbiol 2008; 10:930-44. [DOI: 10.1111/j.1462-5822.2007.01097.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Pak M, Cleveland S. Die Ortsfrequenzgrenze und das Auflösungsvermögen des visuellen Systems der Taube. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060754] [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]
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Wehling P, Pak M, Molsberger A, Winkelmann W. Langzeituntersuchungen zur Reproduzierbarkeit evozierter spinaler Potentiale von chronisch implantierten Ableitelektroden bei der Ratte. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060874] [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]
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Pak M, Hoskins JR, Singh SK, Maurizi MR, Wickner S. Concurrent chaperone and protease activities of ClpAP and the requirement for the N-terminal ClpA ATP binding site for chaperone activity. J Biol Chem 1999; 274:19316-22. [PMID: 10383442 DOI: 10.1074/jbc.274.27.19316] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [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: 11/06/2022] Open
Abstract
ClpA, a member of the Clp/Hsp100 family of ATPases, is both an ATP-dependent molecular chaperone and the regulatory component of ClpAP protease. We demonstrate that chaperone and protease activities occur concurrently in ClpAP complexes during a single round of RepA binding to ClpAP and ATP-dependent release. This result was substantiated with a ClpA mutant, ClpA(K220V), carrying an amino acid substitution in the N-terminal ATP binding site. ClpA(K220V) is unable to activate RepA, but the presence of ClpP or chemically inactivated ClpP restores its ability to activate RepA. The presence of ClpP simultaneously facilitates degradation of RepA. ClpP must remain bound to ClpA(K220V) for these effects, indicating that both chaperone and proteolytic activities of the mutant complex occur concurrently. ClpA(K220V) itself is able to form stable complexes with RepA in the presence of a poorly hydrolyzed ATP analog, adenosine 5'-O-(thiotriphosphate), and to release RepA upon exchange of adenosine 5'-O-(thiotriphosphate) with ATP. However, the released RepA is inactive in DNA binding, indicating that the N-terminal ATP binding site is essential for the chaperone activity of ClpA. Taken together, these results suggest that substrates bound to the complex of the proteolytic and ATPase components can be partitioned between release/reactivation and translocation/degradation.
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Affiliation(s)
- M Pak
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Anderson J, Phan L, Cuesta R, Carlson BA, Pak M, Asano K, Björk GR, Tamame M, Hinnebusch AG. The essential Gcd10p-Gcd14p nuclear complex is required for 1-methyladenosine modification and maturation of initiator methionyl-tRNA. Genes Dev 1998; 12:3650-62. [PMID: 9851972 PMCID: PMC317256 DOI: 10.1101/gad.12.23.3650] [Citation(s) in RCA: 200] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/1998] [Accepted: 10/09/1998] [Indexed: 11/25/2022]
Abstract
Gcd10p and Gcd14p are essential proteins required for the initiation of protein synthesis and translational repression of GCN4 mRNA. The phenotypes of gcd10 mutants were suppressed by high-copy-number IMT genes, encoding initiator methionyl tRNA (tRNAiMet), or LHP1, encoding the yeast homolog of the human La autoantigen. The gcd10-504 mutation led to a reduction in steady-state levels of mature tRNAiMet, attributable to increased turnover rather than decreased synthesis of pre-tRNAiMet. Remarkably, the lethality of a GCD10 deletion was suppressed by high-copy-number IMT4, indicating that its role in expression of mature tRNAiMet is the essential function of Gcd10p. A gcd14-2 mutant also showed reduced amounts of mature tRNAiMet, but in addition, displayed a defect in pre-tRNAiMet processing. Gcd10p and Gcd14p were found to be subunits of a protein complex with prominent nuclear localization, suggesting a direct role in tRNAiMet maturation. The chromatographic behavior of elongator and initiator tRNAMet on a RPC-5 column indicated that both species are altered structurally in gcd10Delta cells, and analysis of base modifications revealed that 1-methyladenosine (m1A) is undetectable in gcd10Delta tRNA. Interestingly, gcd10 and gcd14 mutations had no effect on processing or accumulation of elongator tRNAMet, which also contains m1A at position 58, suggesting a unique requirement for this base modification in initiator maturation.
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Affiliation(s)
- J Anderson
- Laboratory of Eukaryotic Gene Regulation, National Institute of Child Health and Human Development, Bethesda, Maryland 20892 USA
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Kim HY, Pak M, Jakubowski H. A site in the dinucleotide-fold domain contributes to the accuracy of tRNA selection by Escherichia coli methionyl-tRNA synthetase. Mol Cells 1998; 8:623-8. [PMID: 9856352] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Interactions of specific amino acid residues of the carboxyl-terminal domain of MetRS with the CAU anticodon of tRNAMet assure accurate and efficient aminoacylation. The substitution of one such residue, Trp461 by Phe, impairs the binding of cognate tRNA, but enhances the binding of noncognate tRNAs, particularly those containing G at the wobble position. However, the enhanced binding of noncognate tRNAs is not accompanied by the increased aminoacylation of these tRNAs. A genetic screening procedure was designed to isolate methionyl-tRNA synthetase mutants which were able to aminoacylate a GGU (threonine) anticodon derivative of tRNAfMet. One such mutant, obtained from W461F MetRS, had an Ile29 to Thr substitution in helix A located in the amino-terminal dinucleotide-fold domain that forms the site for amino acid activation. Analysis of the catalytic properties of the I29T/W461F enzyme indicates that the mutation in helix A of the dinucleotide-fold domain affects kcat for aminoacylation of tRNAs having a GGU threonine anticodon. Interactions with cognate tRNAfMet (CAU), as well as with methionine and ATP were not affected by the Ile29 to Thr substitution. We conclude that the I29T substitution leads to a slight adjustment of the alignment of the CCA stem of noncognate tRNAs (GGU) in the catalytic domain of the enzyme, reflected in the increase in kcat, which also allows mischarging in vivo. A function of Ile29 is therefore to minimize the mischarging of tRNAThr (GGU) by methionyl-tRNA synthetase. The methods described here provide useful tools for examining the mechanisms of tRNA selection by aminoacyl-tRNA synthetases.
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Affiliation(s)
- H Y Kim
- Department of Food Science and Institute of Genetic Engineering, Kyung-Hee University, Suwon, Korea.
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Abstract
ClpA, a member of the Clp/Hsp100 family of ATPases, is a molecular chaperone and, in combination with a proteolytic component ClpP, participates in ATP-dependent proteolysis. We investigated the role of ClpA in protein degradation by ClpAP by dissociating the reaction into several discrete steps. In the assembly step, ClpA-ClpP-substrate complexes assemble either by ClpA-substrate complexes interacting with ClpP or by ClpA-ClpP complexes interacting with substrate; ClpP in the absence of ClpA is unable to bind substrates. Assembly requires ATP binding but not hydrolysis. We discovered that ClpA translocates substrates from their binding sites on ClpA to ClpP. The translocation step specifically requires ATP; nonhydrolyzable ATP analogs are ineffective. Only proteins that are degraded by ClpAP are translocated. Characterization of the degradation step showed that substrates can be degraded in a single round of ClpA-ClpP-substrate binding followed by ATP hydrolysis. The products generated are indistinguishable from steady-state products. Taken together, our results suggest that ClpA, through its interaction with both the substrate and ClpP, acts as a gatekeeper, actively translocating specific substrates into the proteolytic chamber of ClpP where degradation occurs. As multicomponent ATP-dependent proteases are widespread in nature and share structural similarities, these findings may provide a general mechanism for regulation of substrate import into the proteolytic chamber.
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Affiliation(s)
- J R Hoskins
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
ClpA, a newly discovered ATP-dependent molecular chaperone, remodels bacteriophage P1 RepA dimers into monomers, thereby activating the latent specific DNA binding activity of RepA. We investigated the mechanism of the chaperone activity of ClpA by dissociating the reaction into several steps and determining the role of nucleotide in each step. In the presence of ATP or a nonhydrolyzable ATP analog, the initial step is the self-assembly of ClpA and its association with inactive RepA dimers. ClpA-RepA complexes form rapidly and at 0 degrees C but are relatively unstable. The next step is the conversion of unstable ClpA-RepA complexes into stable complexes in a time- and temperature-dependent reaction. The transition to stable ClpA-RepA complexes requires binding of ATP, but not ATP hydrolysis, because nonhydrolyzable ATP analogs satisfy the nucleotide requirement. The stable complexes contain approximately 1 mol of RepA dimer per mol of ClpA hexamer and are committed to activating RepA. In the last step of the reaction, active RepA is released upon exchange of ATP with the nonhydrolyzable ATP analog and ATP hydrolysis. Importantly, we discovered that one cycle of RepA binding to ClpA followed by ATP-dependent release is sufficient to convert inactive RepA to its active form.
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Affiliation(s)
- M Pak
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Mashimo T, Pak M, Choe H, Inagaki Y, Yamamoto M, Yoshiya I. Effects of vasodilators guanethidine, nicardipine, nitroglycerin, and prostaglandin E1 on primary afferent nociceptors in humans. J Clin Pharmacol 1997; 37:330-5. [PMID: 9115059 DOI: 10.1002/j.1552-4604.1997.tb04310.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 02/04/2023]
Abstract
Although vasodilator agents have been used to alleviate the pain of complex regional pain syndromes, the precise mechanism of pain relief is not well known. In this study the effects of various kinds of vasodilators on primary afferent nociceptors were investigated by measuring the thermal pain threshold. Evaluated in the study were the effects of guanethidine (2 mg/mL), nicardipine (0.2 mg/mL). Nitroglycerin (0.3 mg/mL), and prostaglandin E1 (1 microgram/mL) on the cutaneous pain threshold and blood flow at 7-day intervals in six healthy volunteers. Each aliquot of 0.5 mL of the test vasodilator or lidocaine (10 mg/mL) and saline (control) were intradermally injected at three sites each on both forearms. The pricking-pain threshold and skin tissue blood flow were determined using a radiant heat-stimulating system and a laser-Doppler tissue-blood flowmeter, respectively. The pain threshold increased with lidocaine, guanethidine, and nicardipine; remained unchanged with Nitroglycerin; but decreased with prostaglandin E1. In contrast, the skin tissue blood flow increased by four to nine times with all vasodilators. These results indicate that the effect of vasodilators on primary afferent nociceptors is not related to the vasodilating effect and may not involve a common mechanism of action for pain relief in complex regional pain syndromes.
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Affiliation(s)
- T Mashimo
- Department of Anesthesiology, Osaka University Medical School, Japan
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Pak M, Wickner SH. Pathways of protein remodeling by Escherichia coli molecular chaperones. Genet Eng (N Y) 1996; 18:203-17. [PMID: 8785122 DOI: 10.1007/978-1-4899-1766-9_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- M Pak
- Laboratory of Molecular Biology, National Institutes of Health, Bethesda, MD 20892-4255, USA
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Zhou XM, Pak M, Wang Z, Fishman PH. Differences in desensitization between human beta 1- and beta 2-adrenergic receptors stably expressed in transfected hamster cells. Cell Signal 1995; 7:207-17. [PMID: 7662509 DOI: 10.1016/0898-6568(94)00091-o] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [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: 01/26/2023]
Abstract
It is well-established that agonist-mediated desensitization of the beta 2-adrenergic receptor (beta 2AR) involves its phosphorylation by protein kinase A (PKA) and the beta AR kinase (beta ARK). The phosphorylated receptor is less efficient at mediating agonist stimulation of adenylyl cyclase activity. The result is an increase in the concentration of agonist required for half-maximal stimulation (EC50) and a reduction in maximal stimulation (Vmax). As less is known about desentization of the human beta 1 AR, we compared the desensitization pattern of human beta 1 AR and beta 2AR stably expressed in two different hamster cell lines: Chinese hamster ovary (CHO), and Chinese hamster fibroblast (CHW). Following agonist treatment, all of the cell lines exhibited an increase in EC50, and a reduction in Vmax was observed in CHO-beta 2 but not beta 1 cells. CHW-beta 1 cells were resistant to acute agonist-mediated reduction in Vmax compared to CHW-beta 2 cells. More prolonged agonist exposure produced a modest reduction in Vmax and this effect was more noticeable when the CHW cells expressed lower levels of beta 1AR. To explore the role of protein kinases in these effects, digitonin-permeabilized CHW cells were loaded either with heparin (a beta ARK inhibitor) or a peptide inhibitor of PKA and exposed to agonist. In both beta 2AR- and beta 1AR-expressing cells, heparin inhibited the reduction in Vmax and the PKA inhibitor blocked the increase in EC50. Finally, exposing CHW cells expressing either subtype to a permeable cyclic AMP derivative caused an increase in EC50 similar to that observed in agonist-treated cells, but without any reduction in maximal activity. Our data suggest that whereas PKA-mediated desensitization is not subtype-specific, human beta 1AR is more resistant to beta ARK-mediated desensitization compared to the human beta 2AR.
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Affiliation(s)
- X M Zhou
- Membrane Biochemistry Section, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD 20892, USA
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Pak M, Willis IM, Schulman LH. Analysis of acceptor stem base pairing on tRNA(Trp) aminoacylation and function in vivo. J Biol Chem 1994; 269:2277-82. [PMID: 8294486] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The role of acceptor stem base pairs in determining the identity of Escherichia coli tRNA(Trp) was examined by complementation of an E. coli strain containing a temperature-sensitive tRNA(Trp) gene (trpTts) and by monitoring aminoacylation levels in vivo. All derivatives of tRNA(Trp) containing substitutions at the first 3 base pairs in the acceptor stem complemented the trpTts mutation at the nonpermissive temperature (42 degrees C). However, three acceptor stem derivatives (tRNA(Trp)/C1.G72, tRNA(Trp)/C2.G71, and tRNA(Trp)/A3.U70) required overexpression for growth at 42 degrees C. Northern analysis of these derivatives following acid/urea gel electrophoresis showed no defects in tRNA aminoacylation at the nonpermissive temperature. Instead, these tRNAs appear to be defective in translation. This was suggested by the weak opal suppressor activities of the corresponding tRNA(UCATrp) derivatives. These results demonstrate that the three terminal acceptor stem base pairs do not contribute to the identity of tRNA(Trp). Substitution of the C1.A72 base pair in a methionine initiator tRNA containing the tryptophan anticodon and discriminator base (tRNA(CCAfMet)/G73) with A1.U72, the base pair found in tRNA(Trp), or G1.C72 resulted in the conversion of these tRNAs into tryptophan-inserting elongator tRNAs in vivo. However, changes to U1.A72 or C1.G72 in tRNA(CCAfMet)/G73 resulted in misaminoacylation and/or defects in translation. Our data indicate that the A1.U72 base pair is a context-dependent, negative identity element of tRNA(Trp).
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MESH Headings
- Anticodon/metabolism
- Base Composition
- Base Sequence
- Blotting, Northern
- Escherichia coli/metabolism
- Genetic Vectors
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nucleic Acid Conformation
- Oligodeoxyribonucleotides
- Protein Biosynthesis
- RNA, Transfer, Amino Acyl/metabolism
- RNA, Transfer, Met
- RNA, Transfer, Trp/biosynthesis
- RNA, Transfer, Trp/chemistry
- RNA, Transfer, Trp/metabolism
- Tetrahydrofolate Dehydrogenase/metabolism
- Tryptophan/metabolism
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Affiliation(s)
- M Pak
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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Tomi K, Mashimo T, Tashiro C, Yagi M, Pak M, Nishimura S, Nishimura M, Yoshiya I. Alterations in pain threshold and psychomotor response associated with subanaesthetic concentrations of inhalation anaesthetics in humans. Br J Anaesth 1993; 70:684-6. [PMID: 8329263 DOI: 10.1093/bja/70.6.684] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [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: 01/29/2023] Open
Abstract
We studied the effects of six inhalation anaesthetics at subanaesthetic concentrations of 0.2 MAC on pain threshold and psychomotor function in six healthy volunteers. When compared with 100% oxygen inhalation, nitrous oxide and methyoxyflurane significantly increased pain threshold as measured by a radiant heat algometer, and prolonged the response time to auditory stimuli. In contrast, halothane, enflurane, isoflurane and sevoflurane produced prolongation of the response time to auditory stimuli but did not influence pain perception. The pain threshold with nitrous oxide remained significantly increased 30 min after its discontinuation, while the response time returned to the preinhalation value. We conclude that nitrous oxide and methoxyflurane possess both analgesic and hypnotic actions but halothane, enflurane, isoflurane and sevoflurane do not have an analgesic action at subanaesthetic concentrations, and the analgesic action of nitrous oxide persists after its elimination.
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Affiliation(s)
- K Tomi
- Department of Anaesthesiology, Osaka University Medical School, Japan
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Mashimo T, Uchida I, Pak M, Shibata A, Nishimura S, Inagaki Y, Yoshiya I. Prolongation of canine epidural anesthesia by liposome encapsulation of lidocaine. Anesth Analg 1992; 74:827-34. [PMID: 1595915 DOI: 10.1213/00000539-199206000-00009] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [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: 12/27/2022]
Abstract
The purpose of our study was to produce a long-acting lidocaine by using a liposome that would entrap the drug. Egg yolk phosphatidylcholine and cholesterol were used as liposome materials. After epidural administration, the pharmacodynamics and pharmacokinetics of liposomal and free lidocaine were studied in 20 dogs. Two percent liposomal or free lidocaine (3.0 mL) was injected into the lumbar epidural space. Nerve blocking effects were estimated by measuring somatosensory evoked potentials. Recovery time from the epidural block in the liposomal lidocaine group (170 +/- 49.5 min) was approximately three times longer than that in the free lidocaine group (61 +/- 18.1 min). The areas under the drug concentration-time curves (AUC0-infinity) and time to maximal concentration (Tmax) in the liposomal lidocaine group were significantly larger than those in the free lidocaine group. These results suggest that the prolongation of epidural blockade by liposomal lidocaine is caused by a slow release of the drug from liposomes. The present study suggests that liposomal lidocaine can be used as a long-acting local anesthetic.
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Affiliation(s)
- T Mashimo
- Department of Anesthesiology, Osaka University Medical School, Japan
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42
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Abstract
The role of the anticodon and discriminator base in aminoacylation of tRNAs with tryptophan has been explored using a recently developed in vivo assay based on initiation of protein synthesis by mischarged mutants of the Escherichia coli initiator tRNA. Substitution of the methionine anticodon CAU with the tryptophan anticodon CCA caused tRNA(fMet) to be aminoacylated with both methionine and tryptophan in vivo, as determined by analysis of the amino acids inserted by the mutant tRNA at the translational start site of a reporter protein containing a tryptophan initiation codon. Conversion of the discriminator base of tRNA(CCA)fMet from A73 to G73, the base present in tRNA(Trp), eliminated the in vivo methionine acceptor activity of the tRNA and resulted in complete charging with tryptophan. Single base changes in the anticodon of tRNA(CCA)fMet containing G73 from CCA to UCA, GCA, CAA, and CCG (changes underlined) essentially abolished tryptophan insertion, showing that all three anticodon bases specify the tryptophan identity of the tRNA. The important role of G73 in tryptophan identity was confirmed using mutants of an opal suppressor derivative of tRNA(Trp). Substitution of G73 with A73, C73, or U73 resulted in a large loss of the ability of the tRNA to suppress an opal stop codon in a reporter protein. Base pair substitutions at the first three positions of the acceptor stem of the suppressor tRNA caused 2-12-fold reductions in the efficiency of suppression without loss of specificity for aminoacylation of the tRNA with tryptophan.(ABSTRACT TRUNCATED AT 250 WORDS)
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MESH Headings
- Anticodon
- Base Sequence
- Blotting, Northern
- Chromatography, High Pressure Liquid
- Escherichia coli/genetics
- Genes, Suppressor
- Molecular Sequence Data
- Mutagenesis
- Plasmids
- RNA, Transfer, Amino Acyl/chemistry
- RNA, Transfer, Amino Acyl/genetics
- RNA, Transfer, Met
- RNA, Transfer, Trp/chemistry
- RNA, Transfer, Trp/genetics
- Tetrahydrofolate Dehydrogenase/genetics
- Transformation, Bacterial
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Affiliation(s)
- M Pak
- Department of Developmental Biology and Cancer, Albert Einstein College of Medicine, Bronx, New York 10461
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43
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Abstract
Regeneration of peripheral nerve fibers is impeded by the formation of scar tissue at the site of injury. The possible beneficial effect of collagenase on nerve regeneration was studied using clinical, neurophysiological (evoked potentials) and histological (nerve fiber counts) methods. The sciatic nerves of rats were transected and the severed ends abutted and sewn together. In one series, the area about the lesion was covered with fibrin adhesive and infused with either isotonic saline (controls) or collagenase (treatment group). In the other series, the severed ends of the nerve were inserted into a silicone tube and separated by a collagen plug, which was infused with either saline or collagenase. Compared to the controls, the treated animals showed a significant improvement of clinical and neurophysiological parameters. After 3 months of observation, the collagen content of the transection site was reduced, and in the silicone series, the total number of myelinated axons 5 mm distal to the site of transection was increased, while the fiber diameter distribution was unchanged.
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Affiliation(s)
- P Wehling
- Orthopädische Klinik, Heinrich-Heine-Universität Düsseldorf, Federal Republic of Germany
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44
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Ghanshani S, Pak M, McPherson JD, Strong M, Dethlefs B, Wasmuth JJ, Salkoff L, Gutman GA, Chandy KG. Genomic organization, nucleotide sequence, and cellular distribution of a Shaw-related potassium channel gene, Kv3.3, and mapping of Kv3.3 and Kv3.4 to human chromosomes 19 and 1. Genomics 1992; 12:190-6. [PMID: 1740329 DOI: 10.1016/0888-7543(92)90365-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Genomic and cDNA clones encoding a novel Shaw-related potassium channel gene have been isolated from mice and humans. The mouse-Kv3.3 gene encodes a protein of 679 amino acids. Unlike the vertebrate Shaker-related genes that have intronless coding regions, mouse Kv3.3 is encoded by at least two exons separated by 3 kb of intervening sequence. The amino-terminal 212 amino acids are encoded by a single exon, and the hydrophobic core of the protein beginning at the S1 transmembrane segment is contained in a separate exon. Multiple Kv3.3-hybridizing transcripts are visible in the mouse brain, liver, thymus, and heart. Using probes derived from a human genomic clone containing the 3' exon of human Kv3.3 (KCNC3), we have localized the gene to human chromosome 19. The related gene, human Kv3.4 (KCNC4), was localized to human chromosome 1.
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Affiliation(s)
- S Ghanshani
- Department of Physiology, University of California, Irvine 92717
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45
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Affiliation(s)
- T Mashimo
- Department of Anesthesiology, Osaka University Medical School, Japan
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46
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Wei A, Covarrubias M, Butler A, Baker K, Pak M, Salkoff L. K+ current diversity is produced by an extended gene family conserved in Drosophila and mouse. Science 1990; 248:599-603. [PMID: 2333511 DOI: 10.1126/science.2333511] [Citation(s) in RCA: 262] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Drosophila Shaker gene on the X chromosome has three sister genes, Shal, Shab, and Shaw, which map to the second and third chromosomes. This extended gene family encodes voltage-gated potassium channels with widely varying kinetics (rate of macroscopic current activation and inactivation) and voltage sensitivity of steady-state inactivation. The differences in the currents of the various gene products are greater than the differences produced by alternative splicing of the Shaker gene. In Drosophila, the transient (A current) subtype of the potassium channel (Shaker and Shal) and the delayed-rectifier subtype (Shab and Shaw) are encoded by homologous genes, and there is more than one gene for each subtype of channel. Homologs of Shaker, Shal, Shab, and Shaw are present in mammals; each Drosophila potassium-channel gene may be represented as a multigene subfamily in mammals.
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Affiliation(s)
- A Wei
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110
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