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Takanobu Aoyama

Publications and source records attributed to Takanobu Aoyama.

10 recordsLinked to original sources
PubMed2006

Activation of mitogen-activated protein kinases, activator protein-1, and nuclear factor-kappaB during acute rejection after heterotopic heart transplantation in rats.

BACKGROUND: Activation of mitogen-activated protein kinases (MAPKs), including c-Jun NH2-terminal kinases (JNKs), extracellular signal-regulated kinases (ERKs), and p38MAPK during acute cardiac rejection is not clear. This study aimed to determine whether MAPKs and transcriptional factors such as activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) were involved in acute rejection after cardiac transplantation. METHODS: Hearts from Lewis (LEW) rats (group C) or DA rats (group R) were transplanted into the abdomen of recipients (LEW). Grafts were collected at the 1st, 3rd, or 5th postoperative day (POD). ERKs were measured by Western blot analysis, and JNKs were measured by in-gel kinase assay. AP-1 and NF-kappaB DNA binding activities were determined using an electrophoretic mobility shift assay. We assessed functions of donor hearts using echocardiography. RESULTS: Heart rates and myocardial contraction significantly decreased at POD 5 in group R. Phosphorylated p42ERK and p44ERK in the left ventricular free wall (FW) and septal wall (SW) of group R significantly increased at POD 5 compared to those of group C at POD 1. Activities of p46JNK and p55JNK in the FW and SW of group R also significantly increased at POD 5. AP-1 DNA binding activities in the FW and SW of group R significantly increased at POD 5, and NF-kappaB DNA binding activities of group R significantly increased at PODs 3 and 5. CONCLUSIONS: We conclude that ERK, JNK, AP-1, and NF-kappaB are activated during acute rejection. The MAPK pathways may play an important role in acute cardiac rejection.

Animals↗
PubMed2005

Assembly and deployment of a branched arch stent graft using the transaortic approach.

Transaortic stent grafting is an alternative method for treating distal arch aneurysms. Total arch grafts are too bulky to be inserted into a sheath catheter during usual stent grafting methods. An assembling method that uses a chain stitch enables the deployment of any type of stent graft into the distal aorta without the need for a sheath catheter. We describe how to safely assemble and use a branched arch stent graft. We consider this method to be beneficial in selected cases involving extensive distal arch aneurysms or in patients with highly calcified aortas.

Aorta, Thoracic↗
PubMed2005

Relationship between granulocyte elastase and C3a under protamine dosing in on-pump cardiac surgery.

OBJECTIVE: The complement cascade and granulocytes are activated in on-pump cardiac surgery. If activation of complement directly regulates granulocytes, granulocyte elastase (GEL) should increase significantly after protamine administration. We examined the effect of protamine on granulocytes by protamine administration and observation of the effect on GEL and C3a. METHODS: Thirty patients who underwent coronary artery bypass grafting were randomly assigned to two groups. In 15 patients, protamine was administered 5 min after the termination of cardiopulmonary bypass, and was administered 35 min after cardiopulmonary bypass in the other 15 patients. All patients were perfused with heparin-coated circuits and received 300 IU/kg heparin and 3 mg/kg protamine. GEL and C3a concentrations were measured at 7 time points. RESULTS: GEL concentrations increased significantly just before aortic declamping and did not increase significantly after protamine administration. C3a concentrations, however, did not increase during cardiopulmonary bypass and did increase significantly after protamine administration. CONCLUSIONS: This study indicates that GEL does not increase after protamine administration and that complement concentration does not directly affect GEL release.

Aged↗
PubMed2005

Paradoxical cerebral embolism in a patient with Paget-Schroetter syndrome.

A 28-year-old man presented with transient speech disturbance and right hemiplegia. Computed tomography of the brain revealed a low-density area in the right cerebellum. A ventilation/perfusion lung scintiscan detected multiple perfusion defects in the both lungs and catheterization revealed pulmonary hypertension. Venography of the upper extremities revealed obstruction of the left subclavian vein. Furthermore, Doppler echocardiography revealed a right-to-left shunt via a patent foramen ovale. Those examinations demonstrated paradoxical cerebral embolism caused by Paget-Schroetter syndrome, which is a rare complication of the disorder. We hypothesize that the source of thrombi was the left subclavian vein and surgery was needed to prevent further thromboembolic events. At surgery, the upper half of the sternum was incised in the midline, and the left brachiocephalic vein was ligated. No thromboembolic episodes have occurred postoperatively.

Adult↗
PubMed2003

Rectus abdominis myocutaneous flap after unsuccessful delayed sternal closure.

Open chest management is one of the best options for severely impaired hearts after open-heart surgery. Reapproximation of sternal edges compresses the heart, so a less compressive method of chest wall reconstruction should be considered when sternal closure must be delayed. We applied a rectus abdominis myocutaneous flap approach in 3 patients after difficulties with delayed sternal closures. Two patients were weaned off intraaortic balloon pumping and survived without respiratory troubles or wound complications. This alternative method of chest reconstruction is useful in patients after an unsuccessful delayed sternal closure.

Aged↗
PubMed2003

Mallory - weiss tear complicating intraoperative transesophageal echocardiography.

A Mallory - Weiss tear occurred as a complication of intraoperative transesophageal echocardiography carried out in a 62-year-old man who underwent coronary artery bypass grafting. Left ventricular function was monitored in the transgastric short-axis view. Postoperative esophagogastroscopy revealed a Mallory - Weiss tear at the gastroesophageal junction and erosions in the cardia, presumably secondary to contact pressure by the echoprobe and ultrasonic thermal injury. When not actively imaging, the echoprobe should be left free in the esophagus with the acoustic power off.

Coronary Artery Bypass↗
PubMed2003

Effects of FK506 on acute allograft rejection in transplanted rat heart: the role of mitogen-activated protein kinases, AP-1 and NF-kappaB.

To scrutinize the effect of the immunosuppressant on acute allograft rejection as related to the intracellular signal transduction, heterotopic cardiac transplantation was performed from DA rat to Lewis rat with/without FK506. In the experimental group, recipients were given FK506 intramuscularly for 5 days. The control group received placebo. Allograft survivals were compared between two groups. For the assay of mitogen-activated protein kinase (MAPKs) families, activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) in the left ventricular free wall (LV) and septum (SEP) of the grafts, rats were sacrificed on POD 5 (n=5 in each group). Extracellular signal-regulated kinase (ERK) and p38MAPK were measured using Western blot analysis. AP-1 and NF-kappaB DNA binding activities were measured by electrophoretic mobility shift assay. FK506 prolonged allograft survival (6.5 vs 31 days), and suppressed activation of myocardial MAPKs (ERK: 66% in LV and 67% in SEP, p38MAPK: 62% in LV and 72% in SEP), AP-1 (24% in LV and 18% in SEP), and NF-kappaB (41% in LV and 20% in SEP) (the mean value of activities in the control group was represented as 100%). These results suggest that the signal transduction pathways may play important roles in acute allograft rejection in rat cardiac transplantation.

Acute Disease↗
PubMed2002

Infective endocarditis with myocardial abscesses complicating percutaneous transluminal coronary angioplasty.

A 73-year-old man who had undergone percutaneous transluminal coronary angioplasty developed infectious endocarditis caused by Staphylococcus aureus. Echocardiography revealed vegetations of the aortic valve and severe aortic regurgitation. Endotracheal intubation was required for progressive heart failure. Serum creatinine kinase was elevated (411 IU/l: normal 30 to 140 IU/l). Electrocardiography showed no ischemic changes. Aortic replacement was performed to treat progressive heart failure, but the patient could not be weaned off cardiopulmonary bypass and subsequently died. A post-mortem examination revealed multiple myocardial microabscesses and myocardial infarction due to embolic vegetation. The possibility of multiple abscess formation when severe ventricle dysfunction occurs in infectious endocarditis is emphasized.

Abscess↗
PubMedDate not supplied

Concomitant pulmonary embolectomy and excision of a left atrial myxoma.

We report a rare case of concomitant pulmonary embolectomy and excision of a left atrial myxoma. A 64-year-old obese woman developed a pulmonary embolism 13 days after an operation for a brain tumor. Echocardiography revealed a 3-cm left atrial mass attached to the atrial septum. Urgent surgery, including pulmonary embolectomy and excision of the left atrial mass, was performed. Histopathology confirmed that the mass was a left atrial myxoma. The postoperative course was uneventful.

Brain Neoplasms↗