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Izawa H, Yamada Y, Okada T, Tanaka M, Hirayama H, Murohara T, Yokota M. [Prediction of genetic risk for hypertension]. J Cardiol 2004; 43:92-3. [PMID: 15046042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
BACKGROUND Although genetic epidemiological studies have suggested that several genetic variants increase the risk for hypertension, the genes that underlie genetic susceptibility to this condition remain to be identified definitively. Large-scale association studies that examine many gene polymorphisms simultaneously are required to predict genetic risk for hypertension. METHODS AND RESULTS The population of the present study comprised 1,940 unrelated Japanese individuals, including 1,067 subjects with hypertension (574 men, 493 women) and 873 controls (533 men, 340 women). The genotypes for 33 single nucleotide polymorphisms of 27 candidate genes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay system. Multivariate logistic regression analysis with adjustment for age, body mass index, and the prevalence of smoking, diabetes mellitus, hypercholesterolemia, and hyperuricemia revealed that two polymorphisms (825C -> T in the G protein beta3 subunit gene and 190G -> A in the CC chemokine receptor 2 gene) were significantly associated with hypertension in men and that one polymorphism (-238G -> A in the tumor necrosis factor- alpha gene) was significantly associated with hypertension in women. CONCLUSION These results suggest that two and one genes may be susceptibility loci for hypertension in Japanese men and women, respectively, and that genotyping of these polymorphisms may prove informative for prediction of the genetic risk for hypertension.
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Abstract
Although genetic epidemiological studies have suggested that several genetic variants increase the risk for hypertension, the genes that underlie genetic susceptibility to this condition remain to be identified definitively. Large-scale association studies that examine many gene polymorphisms simultaneously are required to predict genetic risk for hypertension. The population of the present study comprised 1940 unrelated Japanese individuals, including 1067 subjects with hypertension (574 men, 493 women) and 873 controls (533 men, 340 women). The genotypes for 33 single nucleotide polymorphisms of 27 candidate genes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay system. Multivariate logistic regression analysis with adjustment for age, body mass index, and the prevalence of smoking, diabetes mellitus, hypercholesterolemia, and hyperuricemia revealed that 2 polymorphisms (825C-->T in the G protein beta3 subunit gene and 190G-->A in the CC chemokine receptor 2 gene) were significantly associated with hypertension in men and that one polymorphism (-238G-->A in the tumor necrosis factor alpha gene) was significantly associated with hypertension in women. These results suggest that 2 and 1 genes may be susceptibility loci for hypertension in Japanese men and women, respectively, and that genotyping of these polymorphisms may prove informative for prediction of the genetic risk for hypertension.
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Izawa H, Yamada Y, Okada T, Tanaka M, Hirayama H, Yokota M. Prediction of genetic risk for hypertension. HYPERTENSION (DALLAS, TEX. : 1979) 2003. [PMID: 12654703 DOI: 10.116/01.hyp.00000 65618.56368.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although genetic epidemiological studies have suggested that several genetic variants increase the risk for hypertension, the genes that underlie genetic susceptibility to this condition remain to be identified definitively. Large-scale association studies that examine many gene polymorphisms simultaneously are required to predict genetic risk for hypertension. The population of the present study comprised 1940 unrelated Japanese individuals, including 1067 subjects with hypertension (574 men, 493 women) and 873 controls (533 men, 340 women). The genotypes for 33 single nucleotide polymorphisms of 27 candidate genes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay system. Multivariate logistic regression analysis with adjustment for age, body mass index, and the prevalence of smoking, diabetes mellitus, hypercholesterolemia, and hyperuricemia revealed that 2 polymorphisms (825C-->T in the G protein beta3 subunit gene and 190G-->A in the CC chemokine receptor 2 gene) were significantly associated with hypertension in men and that one polymorphism (-238G-->A in the tumor necrosis factor alpha gene) was significantly associated with hypertension in women. These results suggest that 2 and 1 genes may be susceptibility loci for hypertension in Japanese men and women, respectively, and that genotyping of these polymorphisms may prove informative for prediction of the genetic risk for hypertension.
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Matsushita K, Hirayama H, Nanasato M. The importance of intravascular ultrasound in percutaneous coronary intervention for small coronary arteries. J Am Coll Cardiol 2003. [DOI: 10.1016/s0735-1097(03)80232-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Okada T, Yoshida Y, Kondo M, Watanabe K, Mutoh M, Yamada T, Tani T, Yamakami S, Iwata K, Murakami Y, Matsushita T, Okamoto M, Tsuboi N, Hirayama H, Itoh T, Toyama J. Acute hemodynamic effects of pacing therapy on left ventricular function in patients with heart failure and atrial fibrillation: Comparison of left ventricular pacing and biventricular pacing. J Am Coll Cardiol 2003. [DOI: 10.1016/s0735-1097(03)81858-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yamada Y, Izawa H, Ichihara S, Takatsu F, Ishihara H, Hirayama H, Sone T, Tanaka M, Yokota M. Prediction of the risk of myocardial infarction from polymorphisms in candidate genes. N Engl J Med 2002; 347:1916-23. [PMID: 12477941 DOI: 10.1056/nejmoa021445] [Citation(s) in RCA: 499] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Although epidemiologic studies have suggested that several genetic variants increase the risk of myocardial infarction, large-scale association studies that examine many polymorphisms simultaneously are required to allow reliable prediction of the genetic risk of myocardial infarction. METHODS We used a fluorescence- or colorimetry-based allele-specific DNA-primer-probe assay system to determine the genotypes of 112 polymorphisms of 71 candidate genes in 2819 unrelated Japanese patients with myocardial infarction (2003 men and 816 women) and 2242 unrelated Japanese controls (1306 men and 936 women). RESULTS In an initial screening of the 112 polymorphisms for an association with myocardial infarction in 909 subjects, 19 polymorphisms were selected in men and 18 in women by means of logistic-regression analysis, after adjustment for age, body-mass index, and the prevalence of smoking, hypertension, diabetes mellitus, hypercholesterolemia, and hyperuricemia. In a large-scale study involving the selected polymorphisms and the remaining 4152 subjects, similar logistic-regression analysis revealed that the risk of myocardial infarction was significantly associated with the C1019T polymorphism in the connexin 37 gene (P<0.001) in men and the 4G-668/5G polymorphism in the plasminogen-activator inhibitor type 1 gene (P<0.001) and the 5A-1171/6A polymorphism in the stromelysin-1 gene (P<0.001) in women. CONCLUSIONS Determination of the genotypes of the connexin 37, plasminogen-activator inhibitor type 1, and stromelysin-1 genes may prove reliable in predicting the genetic risk of myocardial infarction and might thus contribute to the primary prevention of this condition.
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Makino N, Hirayama H, Yonemochi H, Yano K, Abe N. Cardiac hypertrophy in diabetes patients with and without hypertension: effects of troglitazone, a novel antidiabetic drug, on diastolic function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 498:143-8. [PMID: 11900362 DOI: 10.1007/978-1-4615-1321-6_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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83
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Matsushita K, Tsuboi N, Nanasato M, Takefuji M, Inoue N, Okada T, Yoshida Y, Hasegawa K, Miwata S, Hirayama H, Ito T, Kato W, Tajima K. [Intravenous vegetation of methicillin-resistant Staphylococcus aureus induced by central venous catheter in a patient with implantable cardioverter-defibrillator: a case report]. J Cardiol 2002; 40:31-5. [PMID: 12166247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
A 54-year-old woman with an implantable cardioverter-defibrillator was admitted because of convulsion. Previously, she had suffered methicillin-resistant Staphylococcus aureus (MRSA) sepsis induced by a central venous catheter. Despite removal of the central venous catheter and administration of vancomycin, fever and increased C-reactive protein level persisted. MRSA had probably infected the implantable cardioverter-defibrillator system. Gallium scintigraphy showed accumulation at the right subclaviculan area, although local inflammatory signs were absent. Intravascular ultrasonography demonstrated intravenous vegetation at the bifurcation of the right subclavian vein and right internal jugular vein. Antibiotic therapy was not curative, so she underwent extirpation of the intravenous vegetation, which cured the systemic inflammation. Intravascular ultrasonography was useful to differentiate central venous catheter-related infection from implantable cardioverter defibrillator-related infection.
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Shimizu T, Komuro I, Hirayama H, Hiramitsu S, Shimizu K, Yoshida O. [Drug therapies following heart failure and myocardial infarction(discussion)]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 2002; 60:1235-50. [PMID: 12143782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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85
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Takada Y, Inden Y, Akahoshi M, Shibata Y, Shimizu A, Yoshida Y, Yamada T, Tsuboi N, Hirayama H, Ito T, Kondo T, Saito H, Hirai M. Changes in repolarization properties with long-term cardiac memory modify dispersion of repolarization in patients with Wolff-Parkinson-White syndrome. J Cardiovasc Electrophysiol 2002; 13:324-30. [PMID: 12033346 DOI: 10.1046/j.1540-8167.2002.00324.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Transient T wave changes after cessation of preexcitation have been attributed to cardiac memory. However, there have been no reports on the effects of long-term cardiac memory on repolarization dispersion before and after catheter ablation in patients with Wolff-Parkinson-White (WPW) syndrome. METHODS AND RESULTS We investigated 47 patients with an accessory pathway (AP; 24 manifest left-sided, 14 manifest right-sided, and 9 concealed left-sided). Repolarization dispersion was analyzed by two methods, recovery time (RT) dispersion and newly proposed T wave width (WT), from 87-lead body surface maps before, 1 day after, and 7 days after catheter ablation. RT dispersion and WT were significantly correlated before, 1 day after, and 7 days after catheter ablation (r = 0.78). In patients with preexcitation, RT dispersion and WT increased significantly (P < 0.05) 1 day after catheter ablation (178 +/- 32 msec and 172 +/- 30 msec) compared with those before (154 +/- 24 msec and 156 +/- 18 msec) and 7 days after catheter ablation (147 +/- 19 msec and 156 +/- 16 msec), respectively. However, there were no significant changes in RT dispersion and WT before and after catheter ablation in concealed WPW syndrome. CONCLUSION The findings suggest that the abrupt changes in activation sequence increase repolarization dispersion in the presence of previous cardiac memory, and that the dispersion decreases days or weeks after alteration of activation sequence by catheter ablation, with development of new cardiac memory in patients with manifest WPW syndrome.
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Kurata A, Yamada M, Ohmomo T, Hirayama H, Suzuki S, Miyasaka Y, Irikura K, Fujii K, Kitahara T. The efficacy of coil embolization at the dissection site of ruptured dissecting vertebral aneurysms. Interv Neuroradiol 2002; 7:73-82. [PMID: 20663382 DOI: 10.1177/15910199010070s111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2001] [Accepted: 09/15/2001] [Indexed: 11/15/2022] Open
Abstract
SUMMARY Proximal occlusion of the parent artery has been widely used for treatment of vertebral dissecting ruptured aneurysms, but this does not always completely prevent re-rupture. In this series, the efficacy of occlusion at the dissection site using detachable coils was compared with proximal balloon occlusion. Over a five year period, 25 patients suffering from subarachnoid hemorrhage with dissecting vertebral aneurysms were treated by endovascular surgery. The first three of these 25 patients were treated with proximal balloon occlusion of the parent artery. The remainder underwent platinum coil occlusion at the affected site as early as possible after the diagnosis. In two of the three cases treated with proximal balloon occlusion, clipping or coating surgery were added because of progressive dissection. In all 22 cases of coil embolization, the intervention was successfully performed without complication. In one case with a dissection involving bilateral vertebral arteries, minor rebleeding from a contralateral dissection occurred after embolization. In the other 21 cases, rebleeding was not apparent (clinical follow-up: mean 24 months). Radiological findings showed complete occlusion of the dissection site and patency of the non affected artery (follow-up: mean ten months). We conclude that detachable platinum coil embolization at the dissection site is more effective than proximal occlusion for treatment of ruptured vertebral dissecting aneurysms because of immediate cessation of blood flow to the dissection site. However, in cases with bilateral dissections or hypoplastic contralateral vertebral arteries, preceding bypass surgery or stent treatment to preserve the affected vertebral artery may be needed.
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Nariyama N, Namito Y, Ban S, Hirayama H. Response of GafChromic MD-55 radiochromic film to synchrotron radiation. RADIATION PROTECTION DOSIMETRY 2002; 100:349-352. [PMID: 12382895 DOI: 10.1093/oxfordjournals.rpd.a005886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Synchrotron radiation has been increasingly and extensively used for materials science, biology and medical research. For measurement of high dose from the low energy photons, tissue-equivalent dosemeters having linearity in the Gy region are required. In this study, energy and dose responses of double-layer Gafchromic film MD-55 were measured using 10-40 keV monoenergetic photons from synchrotron radiation. The result showed that the energy responses normalised at 60Co gamma rays were 0.58-0.59 at 10-20 keV, 0.66 at 30 keV and 0.72 at 40 keV in air. The linearity was confirmed to extend from 2 Gy to 100 Gy.
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Nanasato M, Ando A, Isobe S, Nonokawa M, Hirayama H, Tsuboi N, Ito T, Hirai M, Yokota M, Saito H. Evaluation of left ventricular function using electrocardiographically gated myocardial SPECT with (123)I-labeled fatty acid analog. J Nucl Med 2001; 42:1747-56. [PMID: 11752069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
UNLABELLED Electrocardiographically (ECG) gated myocardial SPECT with (99m)Tc-tetrofosmin has been used widely to assess left ventricular (LV) function. However, the accuracy of variables using ECG gated myocardial SPECT with beta-methyl-p-(123)I-iodophenylpentadecanoic acid (BMIPP) has not been well defined. METHODS Thirty-six patients (29 men, 7 women; mean age, 61.6 +/- 15.6 y) with ischemic heart disease underwent ECG gated myocardial SPECT with (123)I-BMIPP and with (99m)Tc-tetrofosmin and left ventriculography (LVG) within 1 wk. LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV) were determined on gated SPECT using commercially available software for automatic data analysis. These volume-related items on LVG were calculated with an area-length method and were estimated by 2 independent observers to evaluate interobserver validity. The regional wall motion with these methods was assessed visually. RESULTS LVEF was 41.1% +/- 12.5% on gated SPECT with (123)I-BMIPP, 44.5% +/- 13.1% on gated SPECT with (99m)Tc-tetrofosmin, and 46.0% +/- 12.7% on LVG. Global LV function and regional wall motion between both gated SPECT procedures had excellent correlation (LVEF, r = 0.943; LVEDV, r = 0.934; LVESV, r = 0.952; regional wall motion, kappa = 0.92). However, the correlations of global LV function and regional wall motion between each gated SPECT and LVG were significantly lower. Gated SPECT with (123)I-BMIPP showed the same interobserver validity as gated SPECT with (99m)Tc-tetrofosmin. CONCLUSION Gated SPECT with (123)I-BMIPP provides high accuracy with regard to LV function and is sufficiently applicable for use in clinical SPECT. This technique can simultaneously reveal myocardial fatty acid metabolism and LV function, which may be useful to evaluate various cardiac diseases.
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Shigino T, Ochi M, Hirose Y, Hirayama H, Sakaguchi K. Enhancing osseointegration by capacitively coupled electric field: a pilot study on early occlusal loading in the dog mandible. Int J Oral Maxillofac Implants 2001; 16:841-50. [PMID: 11769835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Expeditious postoperative appositional growth of bone to dental implants is desired for clinically successful fixation of oral implants. The present study was performed to evaluate the effect of applying a capacitively coupled electric field (CCEF) followed by functional loading on peri-implant osteogenesis in the dog mandible. Nine adult beagles were used in this study. All premolars on both sides of the mandible were removed from each dog. A physio-odontlam implant (POI, Ti-6AI-4v) with 2 stages (3.7 mm in diameter and 8.0 mm in length), whose surface had been treated with anodic oxidation and sandblasted, was placed into each test site by self-tapping. Daily application of CCEF (8 hours per day) was initiated on the day following surgery and continued for 14 days or 21 days. After CCEF treatment was finished for each period, a prosthetic abutment and a straight post were placed on each implant. Four days after placement of the post, implants were placed under functional loading for 30 days. The dogs were then sacrificed, and histologic and radiographic studies of the mandible were performed. Relatively well calcified, mature bone with a lamellar-like structure was observed by contact microradiography and histologic study (double staining with basic fuchsin-methylene blue) of the peri-implant region on the CCEF-treated samples. In contrast, poorly calcified, immature bone without a lamellar structure was observed in control sites not treated with CCEF. The bone area ratios of the CCEF-treated sides were larger than those of control sides. These results suggest that the application of CCEF after implant placement may enhance peri-implant osteogenesis, even with functional loading.
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Sato S, Iida H, Hirayama H, Endo M, Ohwada T, Fujii K. Traumatic basilar artery occlusion caused by a fracture of the clivus--case report. Neurol Med Chir (Tokyo) 2001; 41:541-4. [PMID: 11758706 DOI: 10.2176/nmc.41.541] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 56-year-old man presented with a rare traumatic basilar artery occlusion caused by a fracture of the clivus. He fell from the height of 2 meters and immediately fell into a coma. Head computed tomography (CT) revealed an open depressed fracture, an acute epidural hematoma 1 cm thick in the left middle frontal fossa, and a longitudinal fracture of the clivus. Emergency removal of the hematoma was performed with cranioplasty. Head CT 8 hours 50 minutes after injury showed infarctions in the brain stem, cerebellum, and occipital lobes. Cerebral angiography revealed occlusion of the basilar artery in the middle part of the clivus. The patient died after 3 days. Autopsy revealed that the basilar artery was trapped in the clivus fracture site. Vertebrobasilar artery occlusion due to trapping in a clivus fracture has a very poor prognosis. Diagnosis is difficult and generally only confirmed at autopsy. Cerebral angiography is recommended in a patient in a deep coma without massive brain contusion at the early stage of head injury to identify the possibility of vertebrobasilar artery occlusion in a clivus fracture.
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Tanaka S, Nakashima H, Sakamoto Y, Nakane Y, Meigo S, Tanaka S, Nakamura T, Takada M, Kurosawa T, Hirayama H, Nakao N, Uwamino Y, Imamura M, Shin K. An experimental study on radiation streaming through a labyrinth in a proton accelerator facility of intermediate energy. HEALTH PHYSICS 2001; 81:406-418. [PMID: 11569635 DOI: 10.1097/00004032-200110000-00005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A radiation streaming experiment has been carried out at the Takasaki Ion Accelerator Facility for Advanced Radiation Application at the Japan Atomic Energy Research Institute in a room housing a Cu target irradiated with 68 MeV protons and in a labyrinth of three-legs having a total length of 29 m. In the experiment, neutron and gamma ray energy spectra, neutron reaction rates, and neutron and gamma ray dose equivalent rates were measured using various counters and dosimeters. The experimental data show the applicability of some empirical formulas for estimating the thermal neutron flux in a room and neutrons streaming in a labyrinth designed for a proton accelerator operating in the intermediate energy region. The data suggest that it is mandatory to estimate the gamma ray dose equivalent rate in a labyrinth, which is dominated by the secondary gamma rays due to the neutron capture reaction.
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Hirayama H, Okita Y. H2 control strategy for Na ion channels on the neural cellular membrane. ARTIFICIAL LIFE AND ROBOTICS 2001. [DOI: 10.1007/bf02481349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Terazawa M, Morimoto S, Hirayama H, Hiramitsu S, Hishida H, Hirai M, Saito H. Histopathologic evaluation of coronary artery thrombi obtained by directional coronary atherectomy in patients with restenosis-induced unstable angina pectoris. JAPANESE CIRCULATION JOURNAL 2001; 65:505-8. [PMID: 11407731 DOI: 10.1253/jcj.65.505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pathogenesis of unstable angina pectoris (UAP) following percutaneous transluminal coronary angioplasty (PTCA) or directional coronary atherectomy (DCA) has not been adequately investigated, so the present study aimed to determine whether thrombi are present in restenotic lesions. The study group comprised 14 patients (16 arterial branches) with angina pectoris in whom either PTCA or DCA was performed and who had developed UAP associated with restenosis, and who then underwent DCA of the restenosed lesion (R-UAP group). The control groups comprised individuals with UAP undergoing DCA with no prior history of PTCA or DCA (P-UAP group; n=29, 29 branches), patients with acute myocardial infarction (AMI group; n=34, 34 branches), and patients with stable angina pectoris (SAP group; n=31, 33 branches). The presence of thrombi was determined by light microscopy of histologic specimens. Thrombus was present in only 1 of the 16 (6.3%) branches in the R-UAP group. 21 of the 29 (72.4%) branches in the P-UAP group, and in 25 of the 34 (73.5%) in the AMI group. In the SAP group, it was detected in only 2 of the 33 (7.1%) branches. The incidence of thrombus was significantly lower in the R-UAP group than in the P-UAP group. In conclusion, the role of thrombus is limited in causing post-interventional UAP at restenosed sites.
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Kobayashi H, Beppu S, Hirayama H, Yagura S, Kashiwagi Y, Kayano H, Ishikura F. [Usefulness of intravenous myocardial contrast echocardiography in rats]. J Cardiol 2001; 37:209-14. [PMID: 11337930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVES Few intravenous myocardial contrast echocardiography trials have evaluated myocardial perfusion in small animals. The feasibility of using intravenous myocardial contrast echocardiography to assess the ischemic area in rats was investigated. METHODS Fourteen open chest Wister male rats were examined. Intravenous myocardial contrast echocardiography was performed by fundamental and intermittent mode using a high frequency (5-12 MHz) transducer (SONOS 5500) with injection of NC100100 (20% dilution) into the femoral vein. The mechanical index was set to 1.6. Baseline-subtracted video intensity (256 level) was measured in the anterior, posterior, septal and lateral walls of the left ventricle. The left anterior descending artery was ligated in 16 rats. The area at risk was evaluated by myocardial contrast echocardiography and compared to the area of defect by Evans Blue staining. RESULTS All wall segments were clearly opacified (anterior 63.8 +/- 24.7, posterior 27.0 +/- 11.0, septal 44.5 +/- 11.6, lateral 52.3 +/- 19.1), although the baseline-subtracted video intensity of the posterior wall was low. The area at risk was clearly observed, and there was a good correlation with the nonperfused area by Evans Blue staining (y = 1.13x-3.54, r = 0.98). CONCLUSIONS Intravenous myocardial contrast echocardiography can detect the perfusion defect even in rats using a high frequency transducer and suitable setup of equipment.
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Nariyama N, Namito Y, Ban S, Hirayama H. Dose measurements in inhomogeneous bone/tissue and lung/tissue phantoms for angiography using synchrotron radiation. Phys Med Biol 2001; 46:717-28. [PMID: 11277220 DOI: 10.1088/0031-9155/46/3/308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radiation. The energy responses of the TLDs were measured in air for 10-40 keV monoenergetic photons. The values at 30 keV became smaller by 30% for LiF:Mg, Cu, P and larger by 22% for Mg2SiO4:Tb than the ratio of the mass energy absorption coefficients of the TLDs to that of air. These values were used to modify the calculated response of the TLDs in each phantom material. The absorbed dose distribution obtained was compared with that calculated using the Monte Carlo transport code EGS4 expanded to a low-energy region, and their agreement was confirmed taking linear polarization into account. In the bone substitute the dose increased by a factor of 3.9, while behind the bone the dose decreased drastically because of photon attenuation. In the lung substitute a slight dose difference from that in soft tissue was observed because of its different density. The LiF:Mg, Cu, P TLDs exhibited a better energy response, higher sensitivity and wider linear regions than did the other tissue-equivalent TLDs in the low-energy region.
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Hirayama H, Sugano M, Abe N, Yonemoch H, Makino N. Troglitazone, an antidiabetic drug, improves left ventricular mass and diastolic function in normotensive diabetic patients. Int J Cardiol 2001; 77:75-9. [PMID: 11150629 DOI: 10.1016/s0167-5273(00)00411-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Patients with NIDDM have excessive cardiovascular morbidity and mortality, even in the absence of hypertension. Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in NIDDM patients. METHODS AND RESULTS NIDDM male patients with (n=10) and without (n=12) hypertension, all of whom had been diagnosed over 10 years ago, were examined in the present study. Normotensive NIDDM patients had not received any anti-hypertensive drugs. All patients were classified according to the left ventricular mass (LVM) index by using M-mode echocardiography and were assessed regarding their systolic (fractional shortening) and diastolic function, which included the maximal early flow velocity (MFV), the mitral valve deceleration time (DT), and the isovolumic relaxation time (IRT) as determined by Doppler indices. Troglitazone (TRO), an antidiabetic drug, was administered to both groups at a dose of 400 mg/day for 6 months. After TRO treatment, a reduction in the LVM index and an improvement in the diastolic function were observed in the normotensive but not in the hypertensive patients. CONCLUSION The TRO treatment was sensitive for cardiac regression in those normotensive patients. These results suggest that LVH and the diastolic function in NIDDM patients without hypertension may be associated with elevated insulin resistance because TRO has a pharmacological function to increase the insulin sensitivity and to decrease insulin resistance.
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Nariyama N, Tanaka S, Nakane Y, Nakashima H, Hirayama H, Ban S, Namito Y, Hyodo K, Takeda T. Comparison of in-phantom dose distributions for coronary angiography using an x-ray machine and synchrotron radiation. Med Phys 2001; 28:16-21. [PMID: 11213917 DOI: 10.1118/1.1333744] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Coronary cineangiography using synchrotron radiation is anticipated, owing to the high intensity and availability of monoenergy. To investigate allowable dose levels in clinical application, absorbed dose distribution in a tissue substitute phantom for a conventional x-ray machine was measured with thermoluminescent dosimeters at the University of Tsukuba under the practical conditions used for digital angiography. The dose rate at a 0.5-cm depth was 0.145 Gy/s, and the dose per frame was 0.725 mGy for the irradiation period of 5 ms per frame. For synchrotron radiation, the dose distribution measurement was made at a 5-GeV AR (Accumulation Ring) of the High Energy Accelerator Research Organization, in which a polymethylmethacrylate (PMMA) phantom was irradiated with the strongest beam available at the facility, which was 33.32 keV, 5.2 x 6.2 cm2 beam. Using this beam, a 1-mm-diameter coronary artery has been visualized at 1% iodine concentration at the AR. Nonhomogeneous strength distribution in the beam was observed in the vertical direction. The maximum dose rate was 0.556 Gy/s, and it attenuated to 1/3000 at a 30-cm depth in the beam center. At the deep positions, the doses were influenced by the high harmonics, which was confirmed with an EGS4 Monte Carlo calculation. Outside the beam, beam contamination on both sides of the main beam affected the doses. For comparison to the x-ray machine, the measured dose was analytically converted to that needed for a 5.2 x 16 cm2 beam that is used for clinical application. The dose rate at 0.5-cm depth was found to be 0.215 Gy/s, which is 1.48 times larger than that for x-rays. Moreover, the attenuation rate in the phantom was significantly greater than that of the x-ray machine, because of the difference of the energy spectra between the x-rays and synchrotron radiation used.
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Endo A, Hirayama H, Yoshida O, Arakawa T, Akima T, Yamada T, Nanasato M. Arterial remodeling influences the development of intimal hyperplasia after stent implantation. J Am Coll Cardiol 2001; 37:70-5. [PMID: 11153775 DOI: 10.1016/s0735-1097(00)01038-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES We examined whether preinterventional arterial remodeling influenced the interventional results after stenting. BACKGROUND Arterial remodeling is seen in atherosclerotic lesions, and it may play an important role in the early stage of atherosclerosis. METHODS We examined 113 lesions that underwent elective stenting using tubular slotted stents under intravascular ultrasound guidance. The lesions were divided into three groups--adequate, intermediate and inadequate remodeling group--according to preinterventional arterial remodeling. The patients were subjected to coronary angiography and intravascular ultrasound evaluation on average 6.4 months after stenting. RESULTS At baseline and immediately after stenting, there were no differences in quantitative angiographic analysis among remodeling groups. However, the plaque cross-sectional area (CSA) in the minimal lumen CSA at preintervention and intimal hyperplasia CSA at follow-up were significantly larger in the adequate remodeling group than in the inadequate remodeling group. The restenosis rate of stenting for the lesions with inadequate arterial remodeling was very low (9.4%). A significant positive correlation was found between preinterventional plaque CSA and intimal hyperplasia CSA at follow-up (r = 0.47, p < 0.0001). Moreover, remodeling index significantly correlated with relative intimal hyperplasia CSA (r = 0.28, p < 0.01). CONCLUSIONS Preinterventional arterial remodeling influenced the development of intimal hyperplasia after stenting.
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Hirayama H, Sugano M, Abe N, Yonemochi H, Makino N. Determination of left ventricular mass by echocardiography in normotensive diabetic patients. JAPANESE CIRCULATION JOURNAL 2000; 64:921-4. [PMID: 11194283 DOI: 10.1253/jcj.64.921] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Patients with Type 2 diabetes mellitus (DM) have excessive cardiovascular morbidity and mortality, even in the absence of hypertension. Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in Type 2 DM patients. Forty-two Type 2 DM patients without hypertension, all of whom had been diagnosed more than 10 years ago, were examined in the present study. They had no evidence of renal dysfunction and had not received any anti-hypertensive drugs. Age-matched healthy normal subjects (n=47) were recruited as controls. All participants were classified according to the left ventricular mass index (LVMI) using M-mode echocardiography and their systolic function (fractional shortening) was examined. The systolic function was not significantly different between the Type 2 DM and control groups. LVH can be seen even in the normotensive Type 2 DM patients, with these patients still having a higher LVMI than the normal control subjects. Although the plasma insulin levels were not significantly increased in the Type 2 DM patients, the LVMI significantly correlated with plasma insulin levels. However, the LVMI did not significantly correlate with plasma fasting glucose and hemoglobin A1c in the Type 2 DM patients. These results suggest that LVH in Type 2 DM patients without hypertension may be associated with elevated plasma insulin levels.
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Abstract
Heptakis(2,6-di-O-ethyl)-beta-cyclodextrin (DE-beta-CD) was crystallized in two forms from hexane and 95% aqueous methanol, respectively: A form I crystal with the space group P2(1)2(1)2(1) and a form II crystal with the space group P3(1). In both crystals, DE-beta-CD molecules are in a round shape with intramolecular O-3-H...O-2 hydrogen bonds. In the form I crystal, the DE-beta-CD molecules are arranged along the twofold screw axis to form a helically extended polymeric chain by including the 6-O-ethyl groups of the adjacent molecule. One hexane molecule with twofold disorder is located in the intermolecular channel along the a-axis. In contrast, the DE-beta-CD molecules in the form II crystal form a helical arrangement along the threefold screw axis. One methanol and one water molecule are included on the O-6 side of the molecular cavity. The water molecule links the methanol molecule and two ethoxy groups of the adjacent DE-beta-CD molecule with hydrogen bonds. The result suggests the important role of solvent in the formation of helical arrangement of DE-beta-CD molecules.
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