Early steps for cardiac specification are problematic for the study of mammalian embryos, which has favored using pluripotent cells that recapitulate cardiac myogenesis. Furthermore, circuits governing cardiac specification have relevance to the application of ES cells and other cells for heart repair. In mouse teratocarcinoma cells, canonical Wnts that inhibit heart formation in avian or amphibian embryos and explants activate cardiogenesis, paradoxically. Here, we show that the Wnt/-catenin pathway also is essential for cardiac myogenesis to occur in ES cells, acting at a gastrulation-like stage, mediating mesoderm formation and patterning (two prerequisites for cardiac myogenesis itself). Among genes associated temporally with this step was Sox17, encoding an endodermal HMG-box transcription factor. Using lentiviral vectors for RNA interference in differentiating ES cells, an essential role for Sox17 was proven in cardiac muscle cell formation. Sox17 shorthairpin RNA suppresses cardiac myogenesis selectively, acting subsequent to mesoderm formation yet before induction of Mesp1 and Mesp2, a pair of related basic helix-loop-helix transcription factors that together are indispensable for creating heart mesoderm. Sox17 short-hairpin RNA blocks cardiac myogenesis non-cell autonomously and impairs the induction of Hex, a homeodomain transcription factor that is known to be required for the production of endoderm-derived heart-inducing factors.cardiac myogenesis ͉ differentiation ͉ -catenin ͉ heart ͉ Wnt
A renal vein aneurysm is a rare vascular disease. To our knowledge, only six cases have been reported. We describe a 57-year-old woman with a left renal vein aneurysm diagnosed by a combination of ultrasonography, color Doppler ultrasonography, contrast-enhanced computed tomography, and magnetic resonance imaging.
When these abnormal enhancements of the liver on CT are recognized within the liver, these findings indicate diversion of contrast material into collateral pathways to the liver with SVC obstruction.
We report a case of recurrent malignant fibrous histiocytoma (MFH) in the left atrium, treated by removal of the tumor and the right half of the left atrium, which was reconstructed with two equine pericardial patches. Postoperative echocardiography showed patent right pulmonary veins and a properly shaped left atrium. The patient survived for 3 years after the operation with no cardiac symptoms.
We encountered an informative case of infected aortic arch aneurysm. The proximal descending aorta, left common carotid artery, and left subclavian artery were severely involved in an abscess; thus, typical in situ reconstruction of the arch was considered impossible. Therefore, to secure more distal branches appropriate for anastomosis, a modified extra-anatomic arch repair was performed through additional incisions. The patient developed renal and respiratory failure and died of septicemia five and a half months after the operation. However, postoperative computed tomograms demonstrated that the abscess had disappeared.
We describe herein a rare case of malignant lymphoma occupying almost the entire space of the right atrial cavity and causing low cardiac output syndrome. A life-saving emergency operation was carried out after the establishment of a temporary bypass between the axillary and femoral veins to prevent exacerbation of the patient's condition during the induction of anesthesia. Cardiopulmonary bypass was commenced and the right atrium was opened. A large tumor in the right atrium could not be completely removed due to invasion of the atrial wall. A bypass from the left innominate vein to the pulmonary arterial trunk was constructed with a prosthetic graft to convert the blood flow directly from the systemic vein to the pulmonary artery. Postoperative radiation treatment was given, which resulted in reducing the size of the tumor considerably, and the patient is doing well 1 year after his operation.
We propose discrete mappings of second order that have a discrete analogue of Lyapunov function. The mappings are extensions of the integrable Quispel-RobertsThompson (QRT) mapping, and a discrete Lyapunov function of the mappings is identical to an explicit conserved quantity of the QRT mapping. Moreover we can obtain a differential and an ultradiscrete limit of the mappings preserving the existence of Lyapunov function. We also give applications of a mapping with an adjusted parameter, a probabilistic mapping and coupled mappings.
We report a case with the simultaneous occurrence of pseudo-aneurysm of the left ventricle and ventricular septal rupture, which was successfully surgically repaired. A 77-year-old woman with a history of aortic valve replacement and coronary bypass graft presented to our clinic due to chest pain. She was diagnosed with anterior ST-segment elevation myocardial infarction (STEMI) based on an electrocardiogram. Echocardiography revealed pseudo-aneurysm of the left ventricle and ventricular septal rupture. Coronary angiography revealed 99% stenosis with delayed contrast filling in the mid left anterior descending artery. Surgical repair with a bovine pericardium patch was performed, and the postoperative course was uneventful.
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