Bum Koo Cho

Protective effects of green tea polyphenol against reactive oxygen species-induced oxidative stress in cultured rat calvarial osteoblast.

The injurious effects of reactive oxygen species on osteoblasts and the potential protective role played by green tea polyphenols (GtPP) were investigated using primarily cultured rat calvarial osteoblasts. Oxidative stress was induced in cultured osteoblasts, either by adding 100 mmol/L H2O2 or by the action of 40 U/L xanthine oxidase (XO) in the presence of xanthine (250 μmol/L). After incubation, the cellular viability, function and morphology were evaluated. Both treatments produced a significant reduction in osteoblast viability, as assessed by a two-colored fluorescence staining method combined with flow cytometric analysis and MTT assay. A significant reduction in the alkaline phosphatase activity was observed after H2O2 addition, whereas XO did not have the same effect. On the microscopic observations, the morphological changes and intracellular ultrastructural damages were remarkably induced by both treatments. The H2O2-induced alterations were prevented by pre-incubating the osteoblasts with 200 μg/ml GtPP for 1 h. When the oxidative stress was induced by XO, the cellular viability and morphology was also maintained at the same polyphenol concentration. These results demonstrate that GtPP can act as a biological antioxidant in a cell culture experimental model and protect cells from oxidative stress-induced toxicity.

External compression of bronchus by aneurysm from divided major aortopulmonary collateral artery after unifocalization.

The right ventricle to pulmonary artery connection with an extracardiac conduit, left pulmonary artery reconstruction, ligation of patent ductus arteriosus, and take-down of right Blalock--Taussig shunt were performed on a 1-year-8-month-old boy who had pulmonary atresia, ventricular septal defect, patent ductus arteriosus, and major aortopulmonary collateral arteries. He previously underwent the unifocalization and right modified Blalock--Taussig shunt at 9 months of age. He repeatedly had a difficulty in weaning from the mechanical ventilator. After removing the aneurysm from the divided major aortopulmonary collateral artery that compressed the left main bronchus externally, it was possible to wean him from the mechanical ventilator.

Unusual case of an ectopic spleen

A rate case of a very unusual position of a normally functioning spleen in the posterior aspect of the right lobe of the liver is reported. A 6-year-old boy was evaluated with echocardiography for congenital heart disease of coexisting atrial and ventricular septal defects with pulmonary hypertension. Other associated cardiac abnormalities on this child included a right-sided aortic arch, drainage of the azygous vein into the superior vena cava and an Eisenmenger complex. At the time of echocardiography, absence of the spleen in its normal location was noted. This prompted further investigation into localizing the spleen using 99mTc-sulfur colloid and heat denatured 99m-Tc-RBC scintigraphy. Both scans demostrated the spleen to lie posterior to the right hepatic lobe.

Passion in Cardiothoracic Surgery in Korea: Remembering Professor Pill Whoon Hong, M.D.

Professor Hong was born in Pyeongyang on the 10th of October, 1921 as the fourth of six brothers and sisters in a Christian family. Thanks to his fathers influence as a pastor, he had had early encounters with Western culture. While his oldest sister majored in music and his next-oldest sister studied the science of nursing, he chose to major in medicine. It was the natural choice for him to enroll at Severance Medical School as his sister had, given the Christian influence of his family.

New Era of Asian Cardiovascular and Thoracic Annals

Since its first issue in March 1993, the Asian Cardiovascular & Thoracic Annals has truly been “The Voice of Cardiothoracic Medicine in Asia”, and a dream realized for all regional surgeons. Many of these clinicians had felt the sting of rejection from well-established scientific journals. An opportunity existed for them to share their clinical experiences with colleagues in the East and West through a respected medium.

Characterization of pulmonary microcirculation according to hemodynamic changes with computed tomography

The common and important change of pulmonary hemodynamics is represented by increased or decreased pulmonary blood flow (PBF) and increased pulmonary vascular resistance (PVR). We made 3 hemodynamic models in 5 dogs, that is, increased and decreased PBF model and increased PVR model. CT perfusion scan was performed. Perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT), and maximal slope (MS) were analyzed. In normal state, blood flow was affected by gravity and dependent area showed higher BF, BV and lower MS, MTT than non-dependent area. First, decreased PBF model showed no significant change in BV and elongation of MTT. Secondly, increased PBF model showed slightly increased BV and decreased MTT. Thirdly, increased PVR model showed significant decrease of BF, BV, and MS and slight increase of MTT without statistical significance. However, it was noticeable that the distribution of MTT according to gravity in normal lung was completely reversed in increased PVR model. In conclusion, on the basis of our understanding of perfusion characteristic in normal state, we can detect and evaluate the abnormal regional hemodynamic change in lung. Predicting the change of pulmonary vascular resistance should be possible by thorough analysis of CT perfusion parameters.

Ventriculoarterial Connection for Coronary-Pulmonary Artery Fistula

One-stage ventriculoarterial connection for correction of a coronary artery-to-main pulmonary artery fistula, and transfer of 2 major aortopulmonary collateral arteries from the descending aorta to the right pulmonary artery were successfully accomplished in a 4-month-old boy with pulmonary atresia and a ventricular septal defect.