Double primary cardiac tumors: possible association with a variety of cardiac diseases.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to J Hirota.
Explore the source record for details and available documents.
A 17-year-old woman with scimitar syndrome without an atrial septal defect was operated by intra-cardiac conduit repair. Computed tomography (CT) and magnetic resonance imaging (MRI) showed resolution images of anatomical findings of scimitar vein. Surgical procedures for the scimitar syndrome have varied according to the anatomic features presented in each case. The detection of precise anatomy of scimitar syndrome is important for determining the appropriate surgical procedure. Images of 3-dimensional (3-D) CT and MRI of scimitar syndrome were demonstrated.
Percutaneous transluminal coronary stenting is a proven nonoperative method of direct myocardial revascularization. We encountered a case of iatrogenic significant subacute left main coronary artery stenosis in a patient who had undergone prior percutaneous transluminal coronary artery stenting of the left anterior descending (LAD) artery. Coronary artery bypass grafting was performed. To our knowledge, this is the first report of a surgical case of left main coronary artery stenosis worsened by changes secondary to earlier coronary stenting in the mid portion of left descending coronary artery in Japan.
Gemella morbillorum (G. morbillorum) is part of the commensal flora of the oropharynx and intestinal tract, and on rare occasions causes infective endocarditis. A 55-year-old man with massive aortic regurgitation caused by recurrent infective endocarditis with G. morbillorum had a history of prior endocarditis caused by alpha-hemolytic streptococcus and multiple antibiotic allergies 5 years prior, and was successfully treated by aortic valve replacement. Almost all the reported cases of endocarditis caused by G. morbillorum have been bacteriologically cured with antibiotics and this is the first reported case of recurrent endocarditis caused by G. morbillorum in which the initial infection was bacteriologically cured by antibiotics and the secondary infection treated with valve replacement. This organism can be one of the causes of infective endocarditis and prompt surgical repair is mandatory if the infection is refractory or there is progression of congestive heart failure under antibiotic cover.
Medical therapy for chronic pulmonary thromboembolism is limited, and surgical treatment has become more frequent recently. We have performed pulmonary thromboendarterectomy on a patient with chronic pulmonary thromboembolism accompanied by protein C deficiency. The patient was a woman aged 68 years who had protein C deficiency. The preoperative condition was New York Heart Association functional class IV. Hypoxemia, marked pulmonary hypertension, and low cardiac output were observed. After a median sternotomy, moderate hypothermia was induced using a cardiopulmonary bypass, and thromboendarterectomy in the pulmonary artery was performed. The arterial blood oxygen concentration improved, and the mean pulmonary pressure decreased. The cardiac output also increased, and New York Heart Association functional class improved to I. Pulmonary thromboendarterectomy under cardiopulmonary bypass was effective for chronic pulmonary thromboembolism accompanied by protein C deficiency.
Explore the source record for details and available documents.
Graft replacement for arch aneurysms and concomitant coronary artery bypass grafting (CABG) were performed in four consecutive patients over a three-year period between March 1995 and October 1998. The etiology of the aneurysms was atherosclerosis in all the patients. One early death as a result of a cerebellar infarction occurred on the 74th postoperative day. In all cases, respiratory failure frequently occurred after surgery. In a recent case, the internal mammary artery was used as a graft conduit to the left anterior descending artery (LAD). Both artery and vein grafts were anastomosed to coronary arteries during the initial core cooling. Selective cerebral perfusion was carried out during the reconstruction of the transverse aortic arch and its branches. The left subclavian artery was anastomosed first to secure perfusion to the LAD. To achieve sufficient myocardial protection and obtain good postoperative hemodynamics, CABG was simultaneously performed at the time of aortic aneurysm repair in cases complicated with coronary artery disease.
A 66-year-old woman who received maintenance hemodialysis for the last 14 years was referred to our hospital due to the sudden onset of ischemic stroke and systemic emboli. Transthoracic echocardiography before surgery showed large protruding masses measuring 2 cm which projected into the lumen of the aortic root. The plaque originated on a wide base of the posterior aspect of the ascending aorta at its junction with the sinus of Valsalva. The mobile plaque was surgically removed by endarterectomy from the posterior wall of sino-tubular junction under cardiopulmonary bypass. Pathologic examination of the masses removed at the time of surgery showed that they were atherosclerotic plaque with superimposed thrombi. During operation, transesophageal echocardiography appears to be useful for the rapid detection of a protruding aortic atheroma especially in the initial period of cardiopulmonary bypass until aortic cross clamp.
A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.
A patient with a thrombosed mechanical valve underwent valve re-replacement during which a tumor of the left ventricular outflow tract with the typical macroscopic and microscopic characteristics of a papillary fibroelastoma was successfully removed surgically. The 60-year-old woman had undergone isolated mitral valve replacement with a St Jude Medical 29-mm valve for mitral regurgitation 15 years ago. The present admission was for investigation of dyspnea on exertion. Two-dimensional transthoracic echocardiography demonstrated a posteroseptal, pedunculated mass, measuring 1.3x1.0 cm, in the outflow tract of the left ventricle, mild mitral regurgitation and slight aortic stenosis.
The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R), an IP(3)-gated Ca(2+) channel located on intracellular Ca(2+) stores, modulates intracellular Ca(2+) signaling. During apoptosis of the human T-cell line, Jurkat cells, as induced by staurosporine or Fas ligation, IP(3)R type 1 (IP(3)R1) was found to be cleaved. IP(3)R1 degradation during apoptosis was inhibited by pretreatment of Jurkat cells with the caspase-3 (-like protease) inhibitor, Ac-DEVD-CHO, and the caspases inhibitor, z-VAD-CH(2)DCB but not by the caspase-1 (-like protease) inhibitor, Ac-YVAD-CHO, suggesting that IP(3)R1 was cleaved by a caspase-3 (-like) protease. The recombinant caspase-3 cleaved IP(3)R1 in vitro to produce a fragmentation pattern consistent with that seen in Jurkat cells undergoing apoptosis. N-terminal amino acid sequencing revealed that the major cleavage site is (1888)DEVD*(1892)R (mouse IP(3)R1), which involves consensus sequence for caspase-3 cleavage (DEVD). To determine whether IP(3)R1 is cleaved by caspase-3 or is proteolyzed in its absence by other caspases, we examined the cleavage of IP(3)R1 during apoptosis in the MCF-7 breast carcinoma cell line, which has genetically lost caspase-3. Tumor necrosis factor-alpha- or staurosporine-induced apoptosis in caspase-3-deficient MCF-7 cells failed to demonstrate cleavage of IP(3)R1. In contrast, MCF-7/Casp-3 cells stably expressing caspase-3 showed IP(3)R1 degradation upon apoptotic stimuli. Therefore IP(3)R1 is a newly identified caspase-3 substrate, and caspase-3 is essential for the cleavage of IP(3)R1 during apoptosis. This cleavage resulted in a decrease in the channel activity as IP(3)R1 was digested, indicating that caspase-3 inactivates IP(3)R1 channel functions.
Our previous studies have demonstrated that calmodulin binds to IP3R type I (IP3R1) in a Ca2+ dependent manner, which suggests that calmodulin regulates the IP3R1 channel. In the present study, we investigated real-time kinetics of interactions between calmodulin and IP3R1 as well as effects of calmodulin on IP3-induced Ca2+ release by purified and reconstituted IP3R1. Kinetic analysis revealed that calmodulin binds to IP3R1 in a Ca2+ dependent manner and that both association and dissociation phase consist of two components with time constants of k(a) = 4.46 x 10(2) and > 10(4) M(-1) s(-1) k(d) = 1.44 x 10(-2) and 1.17 x 10(-1) s(-1). The apparent dissociation constant was calculated to be 27.3 microM. The IP3-induced Ca2+ release through the purified and reconstituted IP3R1 was inhibited by Ca2+/calmodulin, in a dose dependent manner. We interpret our findings to mean that calmodulin binds to IP3R1 in a Ca2+ dependent manner to exert inhibitory effect on IP3R channel activity. This event may be one of the mechanisms governing the negative feedback regulation of IP3-induced Ca2+ release by Ca2+.
Inositol 1,4,5-trisphosphate (IP(3)) is an important second messenger that releases intracellular Ca(2+) by binding to its specific receptor, inositol 1,4,5-trisphosphate receptor (IP(3)R), in a wide range of cellular processes. We report here large-scale expression and purification of N-terminal 604 amino acids of IP(3)R type 1 (T604) expressed in E. coli, which contains the ligand binding domain. Surface plasmon resonance biosensor studies showed that purified T604 could bind to its ligands with binding specificity identical to that of full-length native IP(3)R type 1. Kinetic parameters of T604 for IP(3) consisted of a fast association rate constant (K(ass) = 1.2 x 10(6) M(-1) s(-1)) and a rapid dissociation rate constant (k(diss) = 1 s(-1)), and the equilibrium dissociation constant was determined to be 336 nM, at 150 mM NaCl and pH 7.4. However, association and dissociation patterns depended on the pH level and ionic strength. These results pave the way toward detail analysis of structure-function analysis of the ligand binding domain of IP(3)R type 1 for its ligands.
We present herein the case of a 65-year-old man who suddenly developed fresh perigraft bleeding into the space between a knitted Dacron bifurcated graft and the aneurysmal sac, 12 years after undergoing graft replacement. Intraoperative findings did not show Dacron fiber degeneration at the nonanastomotic sites or a pseudoaneurysm at the anastomotic site. Widened Dacron fiber interstices resulting from graft dilation without sufficient graft healing was thought to have caused delayed hemorrhage through the macroscopically intact graft material, followed by massive clot retention between the graft and the aneurysmal sac. This case report serves to demonstrate that careful long-term follow-up is essential for patients who have undergone vascular graft replacement.
Revascularization of the hypogastric artery often tends to be neglected in aortoiliac reconstructive surgery; however, its incomplete revascularization can result in unfavorable complications such as buttock claudication or necrosis, vascular impotence, and colonic ischemia. Multiple vascular lesions in the abdominal aorta and bilateral iliac arteries were reconstructed using a newly designed double bifurcated graft in five male patients. All five patients demonstrated excellent graft limb patency and postoperative improvement of the ankle-brachial pressure index without any clinical signs of ischemia in regions of the hypogastric artery. Thus, we conclude that an aggressive approach toward hypogastric circulation maintenance is essential in aortoiliac reconstructive surgery. By using this double bifurcated graft, rapid and safe revascularization of the bilateral hypogastric arteries concomitant with the external iliac or femoral arteries can be performed.
The dependency of purified mouse cerebellar type 1 inositol 1,4,5-trisphosphate receptor (IP3R1)/Ca2+ channel function on cytoplasmic Ca2+ was examined. In contrast to the channels in crude systems, the purified IP3R1 reconstituted into planar lipid bilayers did not show the bell-shaped dependence on Ca2+. It was activated with increasing Ca2+ sublinearly without inhibition even up to 200 microM. The addition of calmodulin to the cytoplasmic side inhibited the channel at high Ca2+ concentrations. Calmodulin antagonists reversed the Ca2+-dependent inactivation of the native channels in cerebellar microsomes. These results indicate that the bell-shaped dependence on cytoplasmic Ca2+ is not an intrinsic property of the IP3R1, and the Ca2+-dependent inactivation is directly mediated by calmodulin.
An unusual case of an inflammatory abdominal aortic aneurysm (IAAA) associated with coronary aneurysms and pathological fracture of the adjacent lumbar vertebrae. The associated coronary lesions in cases of IAAA are usually occlusions. In the present case, it was concluded that a possible cause of the coronary aneurysm was coronary arteritis and the etiology of the pathological fracture of the lumbar vertebrae was occlusion of the lumbar penetrating arteries due to vasculitis resulting in aseptic necrosis. Inflammatory AAA can be associated with aneurysms in addition to occlusive disease in systemic arteries. The preoperative evaluation of systemic arterial lesions and the function of systemic organs is essential.
BACKGROUND: The aim of this study was to find out whether intravenously administered heparin is distributed equally not only proximal but also distal to the arterial occlusion level in vascular reconstructive surgery. METHODS: Ten consecutive patients (7 men and 3 women) with an average age of 69.9 years (range, 51 to 76 years) who underwent graft replacement for aortic abdominal aneurysm from April to December 1994 were studied. Mean aortic clamp time was 76 minutes. Heparin sodium (100 U/kg) was administered intravenously to keep activated clotting time (ACT) over 250 secs and was neutralized by protamine sulfate (1 mg/kg) just after reperfusion. ACT, blood lactate and CPK-MM in the brachial and dorsal pedis artery were measured before heparin administration (control), just after arterial occlusion, just before reperfusion and 10 minutes after protamine administration. RESULTS: ACT was significantly prolonged after arterial occlusion and recovered after protamine administration with no significant differences between proximal and distal values at each point. Lactate showed significant increase after arterial occlusion which was more remarkable distally. CPK-MM was all the way within the normal range. CONCLUSIONS: In vascular reconstructive surgery which requires temporary arterial occlusion for as long as 80 minutes, the effect of heparin is excellent and equal throughout the body by collateral vessels, and the metabolic influence due to blockade of the blood flow is not so critical as to lead to cellular damage although anaerobic glycolysis is promoted distally due to hypoxia.