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Masanori Murakami

Publications and source records attributed to Masanori Murakami.

12 recordsLinked to original sources
PubMed2006

Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines.

TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-kappaB sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells.

Animals↗
PubMed2006

Stereoselective oxy-functionalization of gamma-silyl allylic alcohols with ozone: a facile synthesis of silyl peroxide and its reactions.

A reaction of gamma-silyl allylic alcohol and its ether with ozone provides synthetically versatile alpha-formyl silyl peroxide in good yield without normal fission of carbon-carbon double bond. Thus, the provided silyl peroxide serves as a good precursor for the stereochemically defined triol derivative via alkylation and reduction of peroxide moiety.

Journal Article↗
PubMed2006

Long-term survival of xenogeneic heart grafts achieved by costimulatory blockade and transient mixed chimerism.

BACKGROUND: Xenotransplantation holds great promise in clinical medicine, but is limited by the vigorous rejection response elicited against solid organs transplanted across species barriers. In this study, we investigated the role of anti-CD40L monoclonal antibody (mAb) in inducing xenogeneic mixed chimerism and donor-specific heart transplantation tolerance. METHODS: One day before heart transplantation, mice were injected intraperitoneally with anti-mouse CD8/NK1.1/Thy1.2 mAbs. On day 0, the mice received 3 Gy total body irradiation (TBI), an intravenous injection of unseparated bone marrow (BM) harvested from F344 rats, and an intraperitoneal injection of hamster antimouse CD40L mAb, MR1. Heart grafts from F344 rats were heterotopically transplanted into the abdomen of B6 mouse recipients. Using flow cytometric analysis of peripheral white blood cells, we assessed donor hematopoiesis at various times after bone marrow transplantation (BMT). RESULTS: Chimerism subsided gradually and disappeared completely 18 weeks after BMT. The cardiac graft survived permanently, even after the mixed chimerism disappeared. To determine if the mice acquired donor-specific tolerance, second rat heart grafts were transplanted 120 days after the first heart transplantation. The second transplanted hearts were also accepted over 60 days. Histological analysis revealed no remarkable vasculopathy in the coronary vessels at any stage. CONCLUSIONS: These findings clearly show that costimulatory blockade plays an important role in inducing xenochimerism, and that transient mixed chimerism can induce permanent acceptance of rat to mouse cardiac xenografts. Transplantation of xenogeneic bone marrow cells under costimulatory blockade at the time of heart transplantation may induce transplantation tolerance.

Animals↗
PubMed2006

Chronic stage left ventricular aneurysm and thrombus after myocardial infarction.

A 60-year-old man had acute myocardial infarction 13 years ago. After percutaneous coronary intervention, the follow-up left ventriculography (8 years ago) showed dyskinesia in the anterolateral and apical segments of the wall. Following this, there was no change in the clinical symptom. After 6 years the patient discontinued aspirin without seeking medical advice. In this year, a thrombus was found in the left ventricle, and thrombectomy was performed. Left ventricular aneurysm has always been a risk for thrombogenesis in any stage, and a periodic follow-up including an echocardiogram and anticoagulation therapy is necessary.

Echocardiography↗
PubMed2006

Tricuspid pouch can cause systemic embolization in adulthood.

A 63-year-old-man with significant left hemiplegia was admitted to hospital. He had experienced a transient cerebral ischemic attack 10 years ago. Computed tomography revealed hypodensity along the right lateral ventricle, which corresponded to the left paralysis. Echocardiography and left ventricular angiography revealed an aneurysm of the membranous septum (AMS) without a ventricular septal defect (VSD). Therefore, the embolism was thought to be of cardiac origin, but surgery revealed that it was not caused by AMS. The aneurysm was created when the septal leaflet of tricupid valve formed a giant capsule during the process of natural closure of the VSD. It was a large pouch, 2.0 cm in diameter, adjacent to the septal leaflet. Anomalies of the tricuspid valve, including pouches, can resemble AMS.

Brain Ischemia↗
PubMed2006

[Blunt right atrial rupture].

Atrial rupture without other major injury following blunt chest trauma is rare, but carries high mortality rate. Here we report 3 cases of blunt atrial rupture. All patients presented with hypotension and loss of consciousness. Echocardiography and computed tomography (CT) demonstrated pericardial effusion in all cases. All patients underwent surgery with a median sternotomy. Tear of the right atrium was seen in 2 patients, and no remarkable tear was seen in 1 patient. One of the 3 patients underwent surgery using cardiopulmonary bypass because he showed cardiogenic shock. Pericardiocentesis before the operation was not effective. All patients were discharged uneventfully. Echocardiography and CT were useful for diagnosis of cardiac rupture. In most reported cases, the cardiac tear has been repaired without using cardiopulmonary bypass. However, it is difficult to diagnose location of the tear, therefore, the repair became safer using cardiopulmonary bypass for the patients with cardiogenic shock. This article has described the mechanisms and generation of blunt chest trauma lesions.

Adult↗
PubMed2006

Right atrial separation effect for chronic atrial fibrillation with atrial septal defect: report of four cases.

We operated on 56 adults diagnosed with atrial septal defect (ASD) between 1990 and 2004. Of these, eight had complications of atrial fibrillation (AF) in the preoperative period. After 1998, right atrial separation was performed in four cases. Marked improvement was noted in three out of the four cases. The right atrial separation procedure was a simple, easy, and effective method for the treatment of chronic AF associated with ASD.

Aged↗
PubMed2006

A sewing needle completely buried in the myocardium removed under extracorporeal circulation.

A 14-year-old boy had a needle accidentally inserted through his chest wall. Chest X-ray showed a needle-shaped metallic density localized in the cardiac silhouette. An echocardiography indicated the needle had passed through the interventricular septum, and its eye and point had reached the right and left ventricle, respectively. Surgical removal of the needle was performed. The needle could not be observed from the heart surface, and was recognized in a dent 5 mm on the right side from the left anterior descending branch (LAD). The needle was easily removed under extracorporeal circulation, and he was discharged ten days after the operation.

Adolescent↗
PubMed2005

Fournier's gangrene treated by simultaneously using colostomy and open drainage.

We report our findings and results on treating a patient with Fournier's gangrene by using colostomy along with open drainage. A 39-year-old male had noticed a swelling and experienced pain in the scrotal sac approximately 1 week before his admission. On admission, his symptoms aggravated and he experienced constipation and difficulty in urination. Local examination of the scrotum circumference revealed a remarkable swelling, and redness and sloughing that had extended to the perianal area. In an emergency operation, incision and drainage of the scrotum, double-barrelled colostomy at the transverse colon, and reconstruction of the percutaneous cystotomy were performed. Postoperative open wound was cleaned twice a day and intravenous infusions of 1g imipenem/cilastatin sodium and 1.2g clindamycin phosphate were administered daily. The patient was discharged 61 days after the operation. Fournier's gangrene has a high mortality rate, and in severe cases that are complicated with infection protracted from defecation, dyschezia and difficulty in urination, we believe that it would be most effective to perform an open drainage and a colostomy simultaneously.

Adult↗
PubMed2005

Surgical treatment for complications of acute myocardial infarction.

OBJECTIVE: We report the results of surgical repair for postinfarction left ventricular free wall rupture (LVFR) and ventricular septal perforation (VSP) complicating acute myocardial infarction. METHODS: We experienced 14 LVFRs and 10 VSPs from January 1991 to December 2002. The mean age of patients with LVFR was 74+/-8.1 years. There were 6 oozing cardiac ruptures and 8 blowout cardiac ruptures. An intraaortic balloon pump (IABP) was inserted in 8 patients, and percutaneous cardiopulmonary support (PCPS) was inserted in 5 patients. The mean age of patients with VSP was 72+/-5.1 years. The rupture was located within the anterior septum in 8 patients and within the posterior septum in 2 patients. All patients required IABP, and one of them needed PCPS. We employed a sutureless technique in 8 patients, direct closure in 5 patients, and infarct exclusion in 1 patient with LVFR. Infarct exclusion was conducted in 9 patients, and the da Silva technique was used in 1 patient with VSP. RESULTS: The patient survival rate of LVFR was 36% (blowout 13%; oozing 67%). Residual shunt occurred in 4 patients with VSP postoperatively. The overall survival rate for VSP was 70%. CONCLUSION: The operative prognosis of blowout cardiac rupture was poor. Good results were obtained with the infarct exclusion technique for patients with VSP. Although some patients had postoperative residual shunts, the infarct exclusion technique was generally a safe and excellent procedure.

Aged↗
PubMed2003

Inhibition of influenza A virus sialidase activity by sulfatide.

Sulfatide, which binds to influenza A viruses and prevents the viral infection, was found to inhibit the sialidase activities of influenza A viruses in a pH-dependent manner. The kinetic parameters of the effect of sulfatide on the sialidase activities of human influenza A viruses using fluorometric assay indicated that sulfatide was a powerful and non-competitive type inhibitor in low-pH conditions.

Animals↗