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Hidehiko Hara

Publications and source records attributed to Hidehiko Hara.

12 recordsLinked to original sources
PubMed2007

Patent foramen ovale: standards for a preclinical model of prevalence, structure, and histopathologic comparability to human hearts.

BACKGROUND: This study evaluated and standardized a Patent Foramen Ovale (PFO) preclinical model in gross anatomic and histopathologic features. METHODS: We examined 150 necropsy-derived domestic porcine hearts, age 4-6 months for PFO prevalence, appearance, and size. Histopathologic preparations were standardized and processed identically to 24 post-mortem human hearts aged 16-62 years. A measurement scheme was developed for PFO atrial openings, tunnel length, and histopathologic features to compare porcine and patient hearts. RESULTS: PFO was found in 32 of the 150 porcine hearts (prevalence 21.3%). Twenty-five porcine PFO underwent standard characterization by tunnel length, and right, and left atrial orifice diameters. Logarithmic regression analysis between porcine PFO tunnel length and left atrial orifice area demonstrated a significant positive relationship (P = 0.0162, R(2) = 0.227). The porcine PFO tunnel length was significantly longer than in humans (12.0 +/- 4.0 mm vs. 7.1 +/- 3.1 mm respectively, P < 0.0001). Histopathologic comparison was made using serial sections perpendicular to the atrial septum and the tunnel long axis. Human and porcine PFO lesions demonstrated strong similarities in tissue cells, connective tissue, and matrix composition. CONCLUSIONS: PFO assessment was standardized in both macroscopically and histopathologically, with quantitative and qualitative comparisons feasible using a porcine preclinical model. PFO prevalence in domestic swine is identical to humans, and microscopic structures very similar to humans. The domestic swine PFO model appears useful to evaluate new interventional closure technologies due to comparability in microscopic features. Tunnel length should be carefully evaluated due to differences across pigs and patients.

Adolescent↗
PubMed2007

Clinical utility of coronary CT angiography: coronary stenosis detection and prognosis in ambulatory patients.

INTRODUCTION: Multislice CT coronary angiography (MSCTA) accurately detects stenosis in patients undergoing coronary arteriography, but its accuracy in clinical outpatients is less certain. This study retrospectively analyzed MSCTA performance in a large outpatient cohort and examined 6-month clinical follow-up in those without invasive CA. METHODS: Patients underwent MSCTA for clinical indications including symptoms or noninvasive results being either equivocal or suspected as incorrect by referring clinicians. Standard 16-slice CT scanner techniques were used, and results were analyzed on the basis of both patient and vessel. Patients were treated medically or sent to invasive angiography on the basis of MSCTA results and judgment of referring clinicians. All invasive angiograms were analyzed using quantitative coronary angiography. Six-month clinical follow-up was determined in patients without CA. RESULTS: One thousand fifty-three consecutive patients were referred for MSCTA, resulting in 994 interpretable scans. Mean age was 58+/-13 years, 55% were male, 50% had prior noninvasive testing, and 90% had symptoms. Invasive angiography was performed in 160 patients, with significant stenoses present in 69%. MSCTA demonstrated 87% and 89% accuracy by patient- and vessel-based analysis, respectively, and was most accurate in the left main and right coronary arteries. Only two patients not referred for angiography had significant stenosis in those undergoing 6-month follow-up. CONCLUSIONS: MSCTA accurately detects obstructive coronary stenosis in clinical patients with possible cardiac symptoms, and effectively triages them for invasive angiography. Negative results are highly accurate in ruling out obstructive disease. Six-month prognosis is excellent in patients without significant disease determined by MSCT.

Aged↗
PubMed2006

Allogeneic MHC gene transfer enhances antitumor activity of allogeneic hematopoietic stem cell transplantation without exacerbating graft-versus-host disease.

Enhancement of the specific antitumor activity of allogeneic hematopoietic stem cell transplantation (alloHSCT) against solid cancers is a major issue in the clinical oncology. In this study, we examined whether intratumoral allogeneic MHC (alloMHC) gene transfer can enhance the recognition of tumor-associated antigens by donor T cells and augment the antitumor activity of alloHSCT. In minor histocompatibility antigen-mismatched alloHSCT (DBA/2-->BALB/c: H-2(d)) recipients, alloMHC gene (H-2K(b)) was transduced directly into a s.c. tumor of CT26 colon cancer cells. Because CT26 cells have an aggressive tumorigenicity in syngeneic BALB/c mice, an H-2K(b) gene transfer provides only a limited antitumor effect after syngeneic (BALB/c-->BALB/c) HSCT. By contrast, the H-2K(b) gene transfer caused significant tumor suppression in the alloHSCT recipients, and this suppression was evident not only in the gene-transduced tumors but also in simultaneously inoculated distant tumors without gene transduction. In vitro cytotoxicity assay showed specific tumor cell lysis by donor T cells responding to the H-2K(b) gene transfer. Graft-versus-host disease was not exacerbated serologically or clinically in the treated mice, demonstrating that alloMHC gene transfer enhances the antitumor effects of alloHSCT without exacerbating graft-versus-host disease. This combination strategy has important implications for the development of therapies for human solid cancers.

Animals↗
PubMed2006

Role of stent design and coatings on restenosis and thrombosis.

More than 15 years have passed since stent technology was introduced by Sigwart et al. [U. Sigwart, J. Puel, V. Mirkovitch, F. Joffe, et al. Intravascular stents to prevent occlusion and restenosis after transluminal angioplasty. N. Engl. J. Med. 316 (1987) 701-706.] among interventional cardiologists. Recently drug eluting stents have assumed dominance in the interventional world as positive trial results revealed their efficacy for preventing restenosis. Stent design, delivery-vehicle materials, and drug properties affect the function of these stents. Stainless steel stents with tubular and multicellular design have proven superior to coil or hybrid stent models. This chapter describes stents which have subtle influences of modular design, metal coverage, strut thickness, strut shape, surface smoothness, and coating materials like an alloy composition.

Biomedical Engineering↗
PubMed2006

Presence and severity of Chlamydia pneumoniae and Cytomegalovirus infection in coronary plaques are associated with acute coronary syndromes.

Although an association between Chlamydia pneumoniae (Cpn) or Cytomegalovirus (CMV) infection and coronary atherosclerosis has been reported, such an association is less clear for acute coronary syndromes (ACS). The purpose of this study was to investigate the pathogenic roles of Cpn and CMV infection of coronary plaques in ACS. We divided 38 coronary plaque specimens obtained from 38 patients who underwent directional coronary atherectomy or thrombectomy into an ACS group (n = 21) and a non-ACS group (n = 17). Cpn and CMV in specimens were stained using immunohistochemical techniques and analyzed quantitatively. The detection rate for either Cpn- or CMV-positive cells in ACS patients was slightly higher compared with non-ACS patients. Detection rates for both Cpn- and CMV-positive cells were significantly higher in ACS patients than in non-ACS patients (P = 0.010). Furthermore, the density of Cpn- and CMV-positive cells in plaques was significantly higher in ACS patients than in non-ACS patients (P < 0.003). The results indicate that the presence and severity of Cpn and CMV infection in coronary plaques are greater in patients with ACS compared with non-ACS patients. We conclude that infection with Cpn and CMV in coronary plaques may be involved in the pathogenesis of ACS.

Aged↗
PubMed2005

Patent foramen ovale: current pathology, pathophysiology, and clinical status.

Patent foramen ovale (PFO) is experiencing increased clinical interest as a congenital cardiac lesion persisting into adulthood. It is implicated in several serious clinical syndromes, including stroke, myocardial infarction, and systemic embolism. The PFO is now amenable to percutaneous interventional therapies, and multiple novel technologies are either available or under development for lesion closure. The PFO should be better understood to take advantage of emerging percutaneous treatment options. This paper reviews PFO anatomy, pathology, pathophysiology, and clinical impact and discusses current therapeutic options.

Heart Septal Defects, Atrial↗
PubMed2005

Fate of unprotected side branches as related to embolic complications during stent implantation for acute coronary syndromes using a distal protection procedure.

Coronary lesion stenting with aspiration and distal balloon occlusion is more often associated with embolic occlusion of interposed side branches when the branch arises at an angle of </=45 degrees and the artery containing the lesion is large. However, this event is infrequent, often resolving during the procedure and uniformly resolving by 6 months.

Aged↗
PubMed2005

Chlamydia pneumoniae immunoreactivity in coronary artery plaques of patients with acute coronary syndromes and its relation with serology.

BACKGROUND: An association between Chlamydia pneumoniae (Cpn) infection and coronary artery disease has been reported and examined by different techniques. However, its immunoreactivity in coronary artery plaques of patients with acute coronary syndrome (ACS) and its relation with serology are less well defined. METHODS: We divided 40 coronary plaque specimens from 40 patients who underwent thrombectomy or directional coronary atherectomy into an ACS group (n = 22) and a non-ACS group (n = 18). Cpn in specimens was detected immunohistochemically and compared quantitatively. Serum immunoglobulin (Ig)A and IgG antibodies to Cpn and high-sensitivity C-reactive protein (hs-CRP) were measured. The relation between serology and immunohistochemical analysis was also investigated. RESULTS: Cpn immunopositive cells per square millimeter (Cpn+ cells/mm2) in the ACS group were significantly more numerous than in the non-ACS group (median 7.44 vs 1.50, P = .0018). Cpn IgA seropositivity rates and titers in the ACS group were significantly higher than those in the non-ACS group (86.3% vs 22.2%, P = .0002; median titer 1.403 vs 0.545, P = .003). There were no differences in IgG antibodies between the 2 groups. The hs-CRP values (in milligrams per liter) in ACS group were significantly higher than in non-ACS group (median 2.8 vs 1.2, P = .0019). Serum IgA titers in patients with at least 5 Cpn+ cells/mm2 in the specimens were significantly higher than in patients with fewer Cpn+ cells (median 1.52 vs 0.86, P = .026). There was no difference in serum hs-CRP values in patients with more Cpn+ cells but a trend to an increase. CONCLUSION: Immunohistology frequently detected Cpn in coronary plaques; Cpn+ cells were more prevalent in plaques associated with ACS, and Cpn IgA but not IgG titers were increased with ACS and with high densities of Cpn+ cells within plaque.

Acute Disease↗
PubMed2004

Hemostatic and fibrinolytic activation is less following cutting balloon angioplasty of the coronary arteries.

Recent studies have shown that percutaneous coronary intervention (PCI) activates systemic hemostatic activity, reflecting platelet activation and thrombin formation in the coronary arteries. The present study compared systemic levels of hemostatic markers induced by plain old balloon angioplasty (POBA), coronary stenting (STENT), and cutting balloon (CB) angioplasty. Sixty-one patients with stable angina pectoris, who underwent elective PCI or diagnostic coronary angiography (CAG) alone, were investigated. Patients who underwent PCI were divided into the POBA group (n = 11), the STENT group (n = 27), and the CB group (n = 11). Patients who underwent CAG alone were assigned to the CAG group (n = 12). Blood samples were collected before, 24 hours after, and 3 days after PCI or CAG. Plasma concentrations of prothrombin fragment 1+2 (F1+2), fibrinopeptide A (FPA), thrombin-antithrombin III complex (TAT), and plasminogen activator inhibitor-1 (PAI-1) were measured. In the CB group, the F1+2 (1.23 +/- 0.4 nmol/L) level 3 days after PCI was significantly smaller than that of the POBA group (2.37 +/- 0.5 nmol/L) (P < 0.05). The FPA (1.81 +/- 0.9 ng/mL), TAT (3.36 +/- 1.2 ng/mL) and PAI-1 (23.0 +/- 4.1 ng/mL) levels in the CB group 3 days after PCI were significantly smaller than those of the POBA group (P < 0.05, respectively) and STENT group (P < 0.05, respectively), but similar to the CAG group. Systemic hemostasis is activated to a greater extent after POBA and stenting than it is after CB angioplasty of the coronary arteries. This may contribute to the favorable long-term outcome of CB angioplasty.

Aged↗
PubMed2004

[Dilated cardiomyopathy].

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Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Left atrial thrombus causing pulmonary embolism by passing through an atrial septal defect.

A 66-year-old woman admitted with dyspnea on exertion had atrial fibrillation and left ventricular dysfunction. Echocardiography revealed an atrial septal defect (ASD) and a soft, easily deformable thrombus in the dilated left atrium. The atrial mass suddenly disappeared on the 10th day after admission, and contrast-enhanced chest computed tomography and pulmonary blood flow scintigraphy showed that the thrombus had detached from the left atrium, floated into the right atrium through the ASD and caused pulmonary embolism. This is the first documented case of a left atrial thrombus causing pulmonary embolism by passing through an ASD. When an ASD is present, it is important to consider not only paradoxical thromboembolism (from the right to the left atrium), but also pulmonary embolism caused by thromboembolism from the left to the right atrium.

Aged↗