Protein-Ligand Interaction Analyses with Nuclear Magnetic Resonance Spectroscopy Enhanced by Dissolution Triplet Dynamic Nuclear Polarization

Solution-state nuclear magnetic resonance spectroscopy (NMR) is a powerful method for the analysis of intermolecular interactions within a biomolecular system. However, low sensitivity is one of the major obstacles of NMR. We improved the sensitivity of solution-state ¹³C NMR for the observation of intermolecular interactions between protein and ligand using hyperpolarized solution samples at room temperature. Eutectic crystals composed of ¹³C-salicylic acid and benzoic acid doped with pentacene were hyperpolarized by dynamic nuclear polarization using photoexcited triplet electrons, and a ¹³C nuclear polarization of 0.72 ± 0.07% was achieved after dissolution. The binding of human serum albumin and ¹³C-salicylate was observed with several hundred times sensitivity enhancement under mild conditions. The established ¹³C NMR was applied for pharmaceutical NMR experiments by observation of the partial return of the ¹³C chemical shift of salicylate by competitive binding with other non-isotope-labeled drugs.

[Devising a Technique for Distal Anastomosis During Total Arch Replacement Using the Frozen Elephant Trunk Technique:Delayed Deployment Technique]

Frozen elephant trunk( FET) technique is an effective procedure used to repair aortic arch aneurysm and aortic dissection. We modified FET technique in order to reduce bleeding, which we named "delayed deployment technique." This procedure is performed in the following manner: 1. A tube graft is anastomosed to the proximal descending aorta using open distal method. 2. A FET is deployed within the tube graft and the descending aorta. 3. Proximal end of the inner FET and the outer tube graft is trimmed at the same position. 4. A four-branched graft is anastomosed to doubly layered distal grafts. Since the FET is directly connected to the arch graft, anastomotic site in the proximal descending aorta can be free from direct blood flow. In addition, stent portion of the FET supports the aortic anastomosis from inside. We believe this method is useful for hemostasis.

[Treatment of Hemothorax with Bronchial Artery Embolization Combined with Video-assisted Thoracic Surgery Following Hemi-arch Replacement for Stanford Type A Acute Aortic Dissection]

A 51-year-old male arrived at our hospital by ambulance, presenting with a sudden onset of chest pain. Computed tomography (CT) revealed Stanford type A acute aortic dissection. Although emergency hemi-arch replacement was successfully performed, the blood pressure decreased and anemia acutely progressed. As chest X-ray revealed right lung opacity, a chest drain was inserted and 3,000 ml of bloody effusion was drawn over a period of 2 hours. Enhanced CT revealed hemothorax and extravasation of the right lung. Since the preoperative CT showed an abnormally dilated right bronchial artery, the branch vessels of the bronchial artery were considered to be the source of hemorrhage. Bronchial artery coil embolization was first performed, which decreased the bronchial artery flow, stabilizing the hemodynamics. Video-assisted thoracic surgery (VATS) was then performed, and the bleeding site at the surface of the lung was electrocauterized. Finally, the hemorrhage was controlled. This case suggests that the combination of coil embolization and VATS is an effective procedure.

[Redo Off-pump Coronary Artery Bypass for Postoperative Vein Graft Stenosis of Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery;Report of a Case]

Bland-White-Garland (BWG) syndrome (anomalous origin of the left coronary artery from the pulmonary artery) is a rare disease which may result in myocardial infarction, congestive heart failure or sometimes death during the early infantile period. We present a 57-year-old female with BWG syndrome. At the age of 20, she was diagnosed with BWG syndrome and underwent coronary artery bypass grafting of a saphenous vein to the proximal portion of the anterior descending branch of the left coronary artery and ligation of the anomalous artery. Thirty-seven years later, she presented with symptoms of angina pectoris and congestive heart failure. Coronary angiography (CAG) revealed stenosis of the saphenous vein graft. Bare metal stent implantation for the saphenous vein graft was performed, but at the 6 months' follow-up CAG revealed restenosis. Drug-eluting stent was then implanted, but in-stent restenosis recurred 4 months later. We performed off-pump coronary artery bypass grafting to the left anterior descending artery using the left internal thoracic artery. The postoperative course was uneventful.

A presumed mechanism of mitral regurgitation after left ventriculoplasty

After isolated left ventriculoplasty, the mechanism of mitral regurgitation (MR) remains unclear. A 68-year-old male with ischemic cardiomyopathy presented with a new onset of severe MR after left ventriculoplasty without a mitral procedure. He needed a second operation for heart failure because of the MR. We speculate about its mechanism and express caution about the procedure.

Microembolization from an abdominal aortic aneurysm after thoracic aortic replacement

A 66-year-old man with thoracic and abdominal aortic aneurysm suffered from microembolism in the lower extremities after total arch replacement. He presented with livedo reticularis with palpable peripheral pulses, and the serum creatinine kinase level elevated up to 7,695. The abdominal aortic aneurysm, but not the thoracic aorta, was the origin of this complication. The morphological change of thrombus in the abdominal aorta detected by ultrasonography was the key to the diagnosis. Graft replacement of the abdominal aorta finally resolved his problem.

Spontaneous perigraft hematoma suggesting transgraft hemorrhage seven years after thoracic aortic replacement with a Dacron graft

As a previously unrecognized late graft-related complication, we report a case of spontaneous perigraft hemorrhage, which was evidenced by contrast extravasation on computed tomographic scan seven years after thoracic aortic replacement with a knitted Dacron graft. There was no anastomotic problem or graft tear, and the hematoma seemed to result from transgraft hemorrhage. Inadequate graft healing and use of a knitted graft in the thoracic aorta seem underlying. Surgeons should be aware of this complication and we advocate careful long-term follow-up.

Emergency surgical treatment for acute occlusion of the left main coronary artery-report of a case-

We report a case of acute occlusion of the left main coronary artery (LMCA) successfully treated with percutaneous transluminal coronary angioplasty (PTCA) under the use of percutaneous cardiopulmonary bypass support (PCPS) and subsequent coronary artery bypass grafting (CABG). CABG was started only two hours after admission, and subsequent reperfusion of left anterior descending artery (LAD) after completing distal and proximal anastomosis was achieved 60 minutes later. Although postoperative CK levels were elevated to 10,900 IU/l, akinesis of the left ventricular (LV) wall was limited to segment #1 and #2, and hypokinesis in segment #3 and #6 documented by postoperative left ventriculogram (LVG). The patient was discharged from the hospital on foot without neurologic sequelae and is doing well and in New York Heart Association (NYHA) functional class I in 20 months of follow-up. Simultaneous efforts to maintain systemic circulation and to achieve reperfusion of the occluded LMCA as soon as possible are essential for survival. Prompt introduction of mechanical circulatory support and early revascularization to minimize the infarct area are both necessary.