Lucy Youngmin Eun

Overexpression of phosphoinositide-3-kinase class II alpha enhances mesenchymal stem cell survival in infarcted myocardium

The efficacy of mesenchymal stem cell (MSC) therapy for myocardial regeneration is limited by the poor survival of stem cells after transplantation into the infarcted heart. To improve the cell survival of MSCs in the infarcted heart, MSCs were genetically engineered to overexpress phosphoinositide-3-kinase class II alpha (PI3K-C2α). PI3K-C2α overexpression increased PI3K expression and the cell viability of MSCs. Furthermore, levels of survival-related phosphorylation were elevated in PI3K-C2α-MSCs. But, the level of apoptotic proteins downregulated and the number of PI-positive cells decreased in PI3K-C2α-MSCs compared to hypoxic MSCs. Nine rats per group had 1×10(6) cells (20 μl PBS) transplanted after myocardial infarction. One week after transplantation, infarct size and area of fibrosis were reduced in the PI3K-C2α-MSC-transplanted group. The number of TUNEL positive cells declined, while the mean microvessel count per field was higher in the PI3K-C2α-MSC group than the MSC-injected group. Heart function was improved in the PI3K-C2α-MSCs group as assessed using a Millar catheter at 3weeks after transplantation. These findings suggest that overexpression of PI3K-C2α in MSCs can assist cell survival and enhance myocardial regeneration.

Aortic Dissection and Rupture in a Child

After developing sudden severe chest pain, an 11-year-old boy presented to the emergency room with chest pain and palpitations and was unable to stand up. The sudden onset of chest pain was first reported while swimming at school about 30 minutes prior to presentation. Arterial blood pressure (BP) was 150/90 mmHg, heart rate was 120/minute, and the chest pain was combined with shortness of breath and diaphoresis. During the evaluation in the emergency room, the chest pain worsened and abdominal pain developed. An aortic dissection was suspected and a chest and abdomen CT was obtained. The diagnosis of aortic dissection type B was established by CT imaging. The patient went to surgery immediately with BP control. He died prior to surgery due to aortic rupture. Here we present this rare case of aortic dissection type B with rupture, reported in an 11-year-old Korean child.

A Case of Vitiligo after Kawasaki's Disease

Vitiligo is a common skin disease, but its pathogenesis has not been fully determined, though an autoimmune etiology is considered likely. Kawasaki disease (KD) is an acute multisystem vasculitis of childhood associated with coronary arteriopathy, and is diagnosed based on clinical criteria. Furthermore, vitiligo has been associated with several other diseases, but no report has been issued about the relationship between vitiligo and Kawasakis disease. The authors report the case of an 8-year-old male child that presented with depigmented lesions, which developed from the desquamative skin lesions of Kawasakis disease.