Images in cardiovascular medicine. Severe endothelial dysfunction after sirolimus-eluting stent implantation.
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Acetylcholine↗
Biomedical subjects
Hironori Saito
Publications and source records attributed to Hironori Saito.
Effects of intraaortic balloon pumping on the angiographic no-reflow phenomenon after percutaneous coronary intervention in patients with anterior myocardial infarction.
BACKGROUND: The effects of intraaortic balloon pumping (IABP) are considered to be a reduction in myocardial oxygen demand because of systolic left ventricular unloading and an increase in coronary blood flow. Although the former effect has been consistently recognized, the latter effect remains controversial. The purpose of this study was to examine the effects of IABP on the angiographic no-reflow phenomenon. METHODS AND RESULTS: The coronary flow velocity pattern of the left anterior descending artery (LAD) was assessed by transthoracic Doppler echocardiography during IABP counterpulsation, and the effects of IABP were compared between angiographic no-reflow and good reflow patients. The study group comprised 17 patients with anterior myocardial infarction who underwent percutaneous coronary intervention and IABP for typical clinical indications. Echocardiographic data were obtained during 2:1 balloon pumping after coronary angioplasty. In the good reflow group (n=9), IABP counterpulsation increased the mean diastolic flow velocity (MDFV) and peak diastolic flow velocity (PDFV) by 56 +/- 32% (p<0.001) and 48 +/- 27% (p<0.001), respectively. In contrast, in the no-reflow group (n=8), IABP only increased the MDFV and PDFV by 19 +/- 33% (p=0.24) and 6 +/- 12% (p=0.22), respectively. Diastolic deceleration time was smaller and the prevalence of systolic retrograde flow was greater in the no-reflow group than in the good reflow group, and IABP affected neither parameter. CONCLUSIONS: IABP had limited effects on LAD flow velocity pattern in patients with the angiographic no-reflow phenomenon.
Aged↗
Isolation and functional characterization of a novel organic solute carrier protein, hOSCP1.
We succeeded in isolating a novel organic solute carrier from a human placenta cDNA library. The isolated cDNA consisted of 1137 base pairs that encoded a 379-amino acid protein, hOSCP1. Northern blot and reverse transcription PCR analyses revealed that the hOSCP1 mRNA is expressed in the placenta and testis and weakly expressed in the thymus and small intestine. When expressed in Xenopus laevis oocytes, hOSCP1 mediated the high affinity transport of p-aminohippurate (PAH) (K(m) = 35.0 +/- 7.5 microm) and tetraethylammonium (K(m) = 62.3 +/- 12.2 microm) in a sodium-independent manner. However, the hOSCP1-expressing oocyte did not mediate the transport of L-carnitine. The transport of PAH by hOSCP1 was sensitive to pH, but the tetraethylammonium was not transported at the high pH examined. hOSCP1 transported prostaglandin E(2), prostaglandin F(2alpha), estrone sulfate, glutarate, L-leucine, L-ascorbic acid, and tetracycline. Thus, hOSCP1 also showed broad substrate specificity. A wide range of structurally unrelated organic compounds inhibited the hOSCP1-mediated PAH uptake. Immunohistochemical analysis revealed that the hOSCP1 protein is localized in the basal membrane of the syncytiotrophoblast in the human placenta. Our results suggest that hOSCP1 is a novel polyspecific organic solute carrier protein responsible for drug clearance from the human placenta.
Amino Acid Sequence↗
Relationship between oxidative stress and systolic dysfunction in patients with hypertrophic cardiomyopathy.
BACKGROUND: Progression of hypertrophic cardiomyopathy (HCM) to left ventricular dilatation and systolic dysfunction sometimes occurs. However, the mechanism is not known. We examined whether oxidative stress was elevated in myocardia of HCM patients and whether the levels were correlated with left ventricular dilatation and systolic dysfunction. METHODS AND RESULTS: Endomyocardial biopsy samples obtained from the right ventricular side of the septum of 31 patients with HCM, and 10 control subjects were studied immunohistochemically for the expression of 4-hydroxy-2-nonenal (HNE)-modified protein, which is a major lipid peroxidation product. Expression of HNE-modified protein was found in all myocardial biopsy samples from patients with HCM. Expression was distinct in the cytosol of cardiomyocytes. The expression levels in patients with HCM were significantly increased compared with those in control subjects (P = .0005). The expression levels in patients with HCM were correlated with left ventricular end-diastolic diameter (r = 0.483, P = .0053) and end-systolic diameter (r = 0.500, P = .0037) determined by echocardiography. The expression levels were inversely correlated with left ventricular ejection fraction determined by left ventriculography (r = -0.640, P = .0001). CONCLUSION: Oxidative stress was elevated in myocardia of HCM patients and the levels were correlated with left ventricular dilatation and systolic dysfunction. Oxidative stress is involved in the pathogenesis of heart failure in patients with HCM.
Aldehydes↗
Risk of alveolar hemorrhage in patients with primary pulmonary hypertension--anticoagulation and epoprostenol therapy.
BACKGROUND: Anticoagulation therapy and continuous intravenous infusion of epoprostenol are the standard treatment for primary pulmonary hypertension (PPH). Because epoprostenol has an antiplatelet effect, concomitant use of an anticoagulant could increase the likelihood of hemorrhagic complications. METHODS AND RESULTS: In the present study, 31 consecutive patients with PPH (10 men, 21 women, mean +/- SD age, 28.5+/-10.1 years) treated with anticoagulation and epoprostenol between April 1999 and December 2003 were retrospectively evaluated. Clinical and hematological data at the time of the bleeding episode were retrieved from the medical records. Nine patients (22.6%) experienced 11 bleeding episodes: 9 episodes (81.8%) were alveolar hemorrhage and 2 patients were in severe respiratory distress. The mean dose of epoprostenol at the time of the first bleeding episode was 89.0 +/-40.5 ng.kg(-1).min(-1) (range, 28.1-164.0). More of the patients who did not have a bleeding episode remain alive than did patients with bleeding episodes (59% vs 33%) nor did they require lung transplantation. CONCLUSIONS: A considerable number of patients with PPH who received combined anticoagulant and high-dose epoprostenol therapy developed alveolar hemorrhage, which can be fatal.
Adolescent↗
Effect of a kink in unilateral pulmonary artery anastomosis on velocities of blood flow through bilateral pulmonary vein anastomoses in living-donor lobar lung transplantation.
Intraoperative transesophageal echocardiography is generally performed to detect vascular complications during lung transplantation. We report a case with a kink in pulmonary artery (PA) anastomosis suggested by an abnormal flow profile of pulmonary vein (PV) anastomoses during living-donor lobar lung transplantation. During the transplantation, velocity of blood flow through the right PV anastomosis showed abnormal elevation. Then, the patient's PA pressure elevated abnormally and a kink in the left PA anastomosis was found. Careful monitoring of PV anastomoses may enable detection of not only an abnormality of PV anastomoses but also that of PA anastomoses, especially in living-donor lobar lung transplantation.
Adult↗
Differences between flow profiles of pulmonary vein anastomoses affected by peripheral atelectasis in cadaveric and bilateral living-donor lobar lung transplantations.
We report two cases of peripheral atelectasis during cadaveric and living-donor lobar lung transplantation, which had different effects on the flow profile of pulmonary vein (PV) anastomoses. In the patient who underwent living-donor lobar lung transplantation, we detected the increase in the velocity of blood flow through the left PV anastomosis by intraoperative transesophageal echocardiography. Then peripheral atelectasis occurred in the transplanted left lung lobe. On the other hand, in the patient who underwent cadaveric bilateral lung transplantation, peripheral atelectasis occurred, but no changes in velocities of blood flow through PV anastomoses were detected by intraoperative transesophageal echocardiography. This difference may have been caused by the difference in sizes of pulmonary beds of transplanted grafts. These findings indicate the necessity of careful monitoring of PV anastomoses, especially in cases of living-donor lobar lung transplantation.
Adult↗
Sinus node function in patients with Brugada-type ECG.
BACKGROUND: Some studies have shown that patients with Brugada syndrome (BS) have atrioventricular conduction disturbance, but their sinus node function has not been evaluated. METHODS AND RESULTS: The patients group consisted of 59 male patients and 1 female patient with BS. Supraventricular and ventricular programmed electrical stimulation (PES) was performed. Ventricular fibrillation (VF) or sustained polymorphic ventricular tachycardia was induced by ventricular PES in 26 patients with BS (VF group), but was not induced in the other 34 patients (non-VF group). Sinus node function and conduction of the atrioventricular (AV) node in the control group, non-VF group and VF group were evaluated. Sinus node function was attenuated and the His - ventricle interval was prolonged in the VF group (corrected sinus node recovery time: 452+/-126 ms (VF group), 324+/-146 ms (non-VF group), Sino-atrial conduction time: 179+/-60 ms (VF group), 127+/-60 ms (non-VF group), His-ventricle interval: 41+/-9 ms (VF group), 35+/-8 ms (non-VF group)). CONCLUSION: The function of both the sinus node and AV node are attenuated in patients with PES-induced VF.
Adult↗
Significance of the level of monocyte chemoattractant protein-1 in human atherosclerosis.
BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1), a potent chemoattractant for monocytes, plays an important role in the earliest events of atherogenesis. However, direct evidence of the effects of MCP-1 on atherosclerosis in chronic hemodialysis (HD) patients has not been reported. METHODS AND RESULTS: The serum MCP-1 concentrations and the intimal - medial thickness (IMT) in the carotid arteries were measured in 42 non-diabetic chronic HD patients and 20 age-matched controls. The expression of MCP-1 was examined immunohistochemically in radial arterial tissues obtained from the HD patients. IMT and the serum concentration of MCP-1 in the HD patients were both significantly greater than in controls. Multiple regression analysis revealed that the serum concentration of MCP-1 was an independent factor influencing IMT. Tissue immunostaining showed that MCP-1 is expressed in both endothelial and smooth muscle cells and that its level of expression correlates with the serum concentration of MCP-1. CONCLUSIONS: An increase in MCP-1 may be an important factor in the progression of atherosclerosis in non-diabetic HD patients.
Adult↗
Direct evidence for increased hydroxyl radicals in angiotensin II-induced cardiac hypertrophy through angiotensin II type 1a receptor.
Oxidative stress is known to contribute to numerous cardiac disease processes. However, the contribution of reactive oxygen species to cardiac hypertrophy has not yet been fully investigated. The aim of the present study was therefore to determine whether levels of reactive oxygen species were increased in angiotensin II-induced cardiac hypertrophy. We continuously administered angiotensin II (1.1 mg/kg per day) into wild-type and angiotensin II type-1a receptor knockout mice for 2 weeks. The angiotensin II treatment increased blood pressure and heart weight/body weight ratio in wild-type mice but not in knockout mice. The generation of hydroxyl radicals in heart tissue homogenate was directly assessed with electron spin resonance spectroscopy using a spin trapping agent, alpha-phenyl-N-tert butylnitrone. Angiotensin II significantly increased hydroxyl radical production 2.2-fold (p < 0.01) in the hearts of wildtype mice but not in knockout mice. The present study provided direct evidence for increased production of hydroxyl radicals in angiotensin II-induced cardiac hypertrophy through angiotensin II type-1a receptor. These findings in this study may provide important insights into the development of hypertrophy and the transition of hypertrophy to heart failure.
Angiotensin II↗
An N-terminal sequence specific for a novel Homer1 isoform controls trafficking of group I metabotropic glutamate receptor in mammalian cells.
Homer proteins bind to a proline-rich region of the group I metabotropic glutamate receptors (mGluRs) and control their expression and localization at the excitatory postsynaptic density. We isolated a novel isoform of Homer1, Homer1d, from a mouse heart cDNA library. Its N-terminal end of 18 amino acids was unique among Homer1 variants (Homer1a-d), while the remainder of Homer1d was identical to that of Homer1b. To clarify the function of its N-terminus, we expressed Homer1b and 1d in the presence and absence of mGluR5b in HEK293T cells. When expressed alone, both Homer proteins were distributed diffusely in the cytoplasm and mGluR5b was on the plasma membrane (PM). When co-expressed, Homer1d and mGluR5b were co-localized on the PM, while Homer1b and mGluR5b were retained in the endoplasmic reticulum (ER). Both Homer proteins bound to mGluR5b in vitro. Therefore, the N-terminal portion of Homer1d may facilitate trafficking of Homer1-mGluR5 complex from the ER to the PM.
Alternative Splicing↗
Carvedilol decreases elevated oxidative stress in human failing myocardium.
BACKGROUND: Oxidative stress has been implicated in the pathogenesis of heart failure. However, direct evidence of oxidative stress generation in the human failing myocardium has not been obtained. Furthermore, the effect of carvedilol, a vasodilating beta-blocker with antioxidant activity, on oxidative stress in human failing hearts has not been assessed. This study was therefore designed to determine whether levels of lipid peroxides are elevated in myocardia of patients with dilated cardiomyopathy (DCM) and whether carvedilol reduces the lipid peroxidation level. Methods and Results- Endomyocardial biopsy samples obtained from 23 patients with DCM and 13 control subjects with normal cardiac function were studied immunohistochemically for the expression of 4-hydroxy-2-nonenal (HNE)-modified protein, which is a major lipid peroxidation product. Expression of HNE-modified protein was found in all myocardial biopsy samples from patients with DCM. Expression was distinct in the cytosol of cardiac myocytes. Myocardial HNE-modified protein levels in patients with DCM were significantly increased compared with the levels in control subjects (P<0.0001). Endomyocardial biopsy samples from 11 patients with DCM were examined before and after treatment (mean, 9+/-4 months) with carvedilol (5 to 30 mg/d; mean dosage, 22+/-8 mg/d). After treatment with carvedilol, myocardial HNE-modified protein levels decreased by 40% (P<0.005) along with amelioration of heart failure. CONCLUSIONS: Oxidative stress is elevated in myocardia of patients with heart failure. Administration of carvedilol resulted in a decrease in the oxidative stress level together with amelioration of cardiac function.
Adrenergic beta-Antagonists↗