Sachihiko Nobuoka

Acute Myocardial Infarction Induced by Alternating Exposure to Heat in a Sauna and Rapid Cooling in Cold Water

We describe a patient with acute myocardial infarction, which was thought to result from plaque rupture or thrombosis because of coronary artery spasm. The vasospasm was most likely induced by stimulation of the α-adrenergic receptors during alternating heat exposure during sauna bathing and rapid cooling during cold water bathing. This report emphasizes the dangers of rapid cooling after sauna bathing in patients with coronary risk factors.

Relationship between left ventricular ejection fraction and mitral annular displacement derived by speckle tracking echocardiography in patients with different heart diseases.

BACKGROUND Speckle tracking echocardiography (STE)-derived mitral annular displacement (MAD) utilizes the speckle tracking technique to measure strain vectors, which provides accurate estimates of left ventricular ejection fraction (LVEF). Here, we investigated a link between STE-derived MAD and LVEF in patients with different heart diseases and evaluated its clinical usefulness. METHODS This study included 266 outpatients and 84 controls. Of the study patients, 52 patients had ischemic heart disease (IHD), 37 patients had dilated cardiomyopathy (DCM), 34 patients had hypertrophic cardiomyopathy (HCM), 74 patients had valvular heart disease (VHD), and 69 patients had hypertensive heart disease (HHD). STE continuously tracked annular motion throughout the cardiac cycle in the apical 4- and 2-chamber views. RESULTS In all participants, the curvilinear relationship was found between STE-derived MAD and LVEF (R(2)=0.642). The strong correlation between STE-derived MAD and LVEF was also found in the patients with IHD (R(2)=0.733, p=0.001) and in those with DCM (R(2)=0.614, p=0.008). However, such a correlation was not found in the patients with HCM, VHD, or HHD. CONCLUSION The specificity in the correlation between STE-derived MAD and LVEF was found in patients with each heart disease, which should be taken into account when assessing these parameters.

Three-dimensional echocardiographic assessments of exercise-induced changes in left ventricular shape and dyssynchrony in patients with dynamic functional mitral regurgitation

AIMS Left ventricular (LV) shape and LV dyssynchrony are two cofactors associated with functional mitral regurgitation (MR) in patients with heart failure. Both can be accurately examined by real-time three-dimensional echocardiography (3DE). We examined the relationship between dynamic MR and exercise-induced changes in LV shape and synchronicity using 3DE. METHODS AND RESULTS Fifty patients with systolic LV dysfunction underwent 2D and 3D quantitative assessment of LV function, shape, and synchronicity at rest and during symptom-limited exercise test. According to the magnitude of change in MR, patients were divided into EMR group (15 patients, 30%), if the degree of MR increased during test, and NEMR group. During exercise, the changes in LV volumes and ejection fraction were similar in both groups, whereas changes in mitral valvular deformation parameters, in LV sphericity index, and in the extent of LV dyssynchrony were more pronounced in the EMR group. At rest, only the 3D sphericity index could distinguish the two groups. By stepwise multiple regression model, dynamic changes in the systolic dyssynchrony index, sphericity index, and coaptation distance were associated with dynamic MR (r(2) = 0.45, P = 0.012). CONCLUSION Dynamic MR during exercise is related to the 3D changes in LV shape and in LV synchronicity.

Simple exercise echocardiography using a Master's two-step test for early detection of pulmonary arterial hypertension

BACKGROUND Early detection of pulmonary arterial hypertension (PAH) is indispensable, although, echocardiography at rest alone does not provide sufficient evidence for it. Here, this study aimed to investigate the usefulness of simple exercise echocardiography using a Masters two-step test for detecting early PAH. METHODS This study included 52 connective tissue disease patients who had mild symptoms in World Health Organization functional classification 2, suspected as having early PAH, and underwent exercise echocardiography and right heart catheterization. Echocardiography was performed before and after the Masters two-step exercise test; the study patients were classified into the non-PAH (mean pulmonary arterial pressure <25 mmHg, n=37) or PAH (mean pulmonary arterial pressure ≥25 mmHg, n=15) groups. RESULTS Rest systolic pulmonary artery pressure estimated using echocardiography did not significantly differ between the two groups; however, a significant difference in post-exercise systolic pulmonary artery pressure was found (non-PAH, 58.8±10.8 mmHg; PAH, 80.2±14.3 mmHg, p<0.0001). The multiple logistic regression analysis indicated post-exercise systolic pulmonary artery pressure as an independent predictor of PAH (p=0.013). The area under the curve by post-exercise systolic pulmonary artery pressure was 0.91 for PAH. Post-exercise systolic pulmonary artery pressure ≥69.6 mmHg predicted PAH with the sensitivity of 93% and the specificity of 90%. CONCLUSIONS Simple exercise echocardiography using the Masters two-step test could detect PAH in mildly symptomatic connective tissue disease patients. The usefulness of this method should be verified for the early detection of PAH.

Neonatal meningitis caused by Streptococcus gallolyticus subsp. pasteurianus

We encountered a case of neonatal meningitis caused by Streptococcus gallolyticus subsp. pasteurianus. The patient was an 8-day-old boy. Gram staining of the cerebrospinal fluid (CSF) revealed gram-positive cocci in pairs or in short chains. In culture, γ-streptococcus-like colonies grew. The result of 16S rRNA sequence analysis identified S. gallolyticus subsp. pasteurianus. From these results, bacterial meningitis was diagnosed and, as a result of antimicrobial susceptibility testing, single-dose ampicillin therapy was given. Because inflammatory deterioration and spread was suspected from the CSF test results, this therapy was added by panipenem/betamipron. In response to his recovery, antibiotic treatment was stopped and the boy was discharged. This bacterium was classified as S. gallolyticus subsp. pasteurianus in the latest report in 2003. Since this change, there have only been a few cases of neonatal meningitis caused by this bacterium. Here we report this rare case.

Influence of exercise-induced pulmonary hypertension on exercise capacity in asymptomatic degenerative mitral regurgitation.

BACKGROUND Exercise capacity is helpful in the management of patients with mitral regurgitation (MR). However, the determinants of exercise capacity reduction in MR have remained unclear. This study was designed to objectively assess exercise capacity, identify the echocardiographic predictors of exercise capacity, and investigate its impact on development of symptoms in asymptomatic degenerative MR. METHODS A total of 49 consecutive asymptomatic patients (age, 58.9±13.1 years; 82% males) with at least moderate degenerative MR (effective regurgitant orifice area=0.40±0.14cm(2); regurgitant volume=60.9±19.6mL) underwent the symptom-limited cardiopulmonary exercise testing for assessing exercise capacity (peak oxygen uptake, peak V˙O2; the minute ventilation/carbon dioxide production, V˙E/V˙CO2 slope). All patients also underwent exercise stress echocardiography for detecting exercise-induced pulmonary hypertension (EIPH) defined by systolic pulmonary arterial pressure (SPAP) ≥60mmHg. RESULTS The mean peak V˙O2 was 22.6±5.1mL/kg/min (86.7±14.1% of age, gender-predicted); peak V˙O2 widely varied (48-121% of predicted), and was markedly reduced (<80.4% of predicted) in 24% of the study patients. The patients with EIPH had lower 2-year symptom-free survival than those without EIPH (p=0.003). The multivariable analysis demonstrated that EIPH was an independent echocardiographic determinant of peak V˙O2 (p=0.001) and V˙E/V˙CO2 slope (p=0.021). Furthermore, the area under curve of age- and gender-adjusted exercise SPAP was 0.88 (95% confidence interval: 0.78-0.97) for reduced exercise capacity. CONCLUSIONS In asymptomatic moderate to severe degenerative MR, EIPH was independently associated with exercise capacity and predicted the occurrence of symptoms. Exercise stress echocardiography is an important tool in managing patients with asymptomatic degenerative MR.

Influence of Pulmonary Vascular Reserve on Exercise‐Induced Pulmonary Hypertension in Patients with Systemic Sclerosis

Exercise‐induced pulmonary hypertension (PH) is considered as an early preclinical functional phase of resting PH in systemic sclerosis (SSc). In this study, we investigated the prevalence of exercise‐induced PH in patients with SSc and evaluated the influence of pulmonary vascular reserve on exercise‐induced PH.

Value of anatomical aortic valve area using real-time three-dimensional transoesophageal echocardiography in patients with aortic stenosis: a comparison between tricuspid and bicuspid aortic valves.

AIMS Accurate assessment of disease severity is critical for appropriate treatment of patients with aortic stenosis (AS). This study investigated the influence of aortic-valve morphology on the determination of anatomical aortic-valve area (AVA) in patients with AS. METHODS AND RESULTS This prospective study included 126 patients with AS who underwent transoesophageal echocardiography (TEE). Aortic-valve area was measured using (i) planimetric two-dimensional (2D) TEE, (ii) volumetric three-dimensional (3D) TEE, and (iii) the continuity equation (CE) obtained with transthoracic echocardiography. Of these, 20 patients also underwent contrast-enhanced multidetector computed tomography (MDCT). Aortic-valve area was measured from multiplanar reconstruction of the MDCT images. Of the 126 patients, 20 (15.9%) were diagnosed with bicuspid AS and 106 were diagnosed with tricuspid AS. There was an excellent correlation between AVAADCT and AVA3DTEE (r = 0.83, P < 0.001) and a somewhat lower correlation between AVAADCT and AVA2DTEE (r = 0.63, P = 0.006). In the tricuspid AS group, both AVA2DTEE and AVA3DTEE significantly correlated with AVACE (r = 0.63, mean difference 0.13 ± 0.24 cm(2), and r = 0.83, mean difference 0.03 ± 0.12 cm(2), respectively, both P < 0.001). In contrast, in the bicuspid AS group, AVA3DTEE significantly correlated with AVACE (r = 0.83, mean difference 0.10 ± 0.18 cm(2), P < 0.001), whereas AVA2DTEE did not (r = 0.42, mean difference 0.48 ± 0.32 cm(2), P = 0.066). CONCLUSION Aortic-valve morphology influenced the assessment of anatomical AVA in patients with AS, and 3D TEE is useful for assessing anatomical AVA regardless of aortic-valve morphology.

Sonographic characterization of 271 hepatic hemangiomas with typical appearance on CT imaging

PurposeHepatic hemangioma is the most frequent benign solid tumor that requires differentiation from hepatic malignancy on ultrasonography. Useful ultrasound findings are therefore required for diagnosis.Subjects and methodsThe following factors were investigated for 271 masses diagnosed as hepatic hemangioma by contrast-enhanced computed tomography (CT) in 188 patients: hepatic subsegment location, shape, maximum diameter, internal echo level, hyperechoic rim, posterior echoes, marginal hypoechoic band (halo), lateral shadow, blood flow signal in the central portion of the mass, and underlying liver disease.ResultsHepatic masses were classified by internal echo pattern as homogeneous hyperechoic (35.0%), homogeneous hypoechoic (22.9%), isoechoic (5.2%), mixed hyperechoic (22.1%), or mixed hypoechoic (14.8%) masses. Twelve masses were isoechoic, and could be recognized by the hyperechoic rim. Posterior echo enhancement was present in 66 masses. There were no cases of posterior echo attenuation. A halo was present in six masses, with the underlying condition being fatty infiltrated liver in two masses; a hypoechoic region with a small amount of fat deposit was present around the mass, and this resembled a halo. This finding was termed a “pseudohalo.” There were no masses in which a lateral shadow was observed. In terms of blood flow signals in the central portion of the mass, pulsatile flow was present in only one mass.ConclusionsImportant ultrasonographic findings of hepatic hemangioma are characterized as the absence of lateral shadow (100%) and no attenuation of posterior echoes (100%), while the presence of a hyperechoic rim is useful for detecting isoechoic hemangioma.

HP1 regulates the localization of FANCJ at sites of DNA double-strand breaks

The breast and ovarian cancer predisposition protein BRCA1 forms three mutually exclusive complexes with Fanconi anemia group J protein (FANCJ, also called BACH1 or BRIP1), CtIP, and Abraxas/RAP80 through its BRCA1 C terminus (BRCT) domains, while its RING domain binds to BRCA1‐associated RING domain 1 (BARD1). We recently found that the interaction between heterochromatin protein 1 (HP1) and BARD1 is required for the accumulation of BRCA1 and CtIP at sites of DNA double‐strand breaks. Here, we investigated the importance of HP1 and BARD1–HP1 interaction in the localization of FANCJ together with the other BRCA1–BRCT binding proteins to clarify the separate role of the HP1‐mediated pathway from the RNF8/RNF168‐induced ubiquitin‐mediated pathway for BRCA1 function. FANCJ interacts with HP1γ in a BARD1‐dependent manner, and this interaction was enhanced by ionizing radiation or irinotecan hydrochloride treatment. Simultaneous depletion of all three HP1 isoforms with shRNAs disrupts the accumulation of FANCJ and CtIP, but not RAP80, at double‐strand break sites. Replacement of endogenous BARD1 with a mutant BARD1 that is incapable of binding to HP1 also disrupts the accumulation of FANCJ and CtIP, but not RAP80. In contrast, RNF168 depletion disrupts the accumulation of only RAP80, but not FANCJ or CtIP. Consequently, the accumulation of conjugated ubiquitin was only inhibited by RNF168 depletion, whereas the accumulation of RAD51 and sister chromatid exchange were only inhibited by HP1 depletion or disruption of the BARD1–HP1 interaction. Taken together, the results suggest that the BRCA1–FANCJ and BRCA1–CtIP complexes are not downstream of the RNF8/RNF168/ubiquitin pathway, but are instead regulated by the HP1 pathway that precedes homologous recombination DNA repair.