Distinct mobilization of circulating CD271+ mesenchymal progenitors from hematopoietic progenitors during aging and after myocardial infarction.

The specific cell surface markers on mesenchymal stem/progenitor cells (MSCs) have been poorly defined in vivo, but in one recent study, an MSC subpopulation was directly isolated from a CD271-positive fraction of human bone marrow cells. The aim of this study was to identify circulating CD271(+) MSCs in human peripheral blood and investigate whether the cells are mobilized after acute myocardial infarction (MI). A flow cytometric analysis identified CD45(low/-)CD34(+)CD271(+) cells in adult human peripheral blood. The numbers of circulating CD45(low/-)CD34(+)CD133(+) cells (hematopoietic linage progenitors) were significantly lower in elderly subjects without coronary artery disease than in healthy young subjects, whereas the numbers of CD45(low/-)CD34(+)CD271(+) cells were comparable between elderly subjects and younger subjects. The CD45(low/-)CD34(+)CD271(+) and CD133(+) cell counts were both higher in patients with acute MI than in patients with stable coronary artery disease. In our investigation of the time course changes after acute MI, the CD45(low/-)CD34(+)CD133(+) cell counts gradually increased up to day 7. Over the same period, the CD45(low/-)CD34(+)CD271(+) cell counts peaked at day 3 and then declined up to day 7. Importantly, the CD271(+) cell counts at day 3 were positively correlated with the peak concentrations of creatine kinase after acute MI. Results of the present study suggest that the CD271(+) MSCs are mobilized differently from the CD133(+) hematopoietic progenitors and may play a specific role in the tissue repair process during age-related changes and after acute myocardial infarction.

Cardiopulmonary arrest due to persistent coronary spasm in a young woman. Are we properly diagnosing vasospastic angina?

Coronary spasm is a risk factor for acute myocardial infarction and sudden cardiac death. This is a case of a young female patient with cardiopulmonary arrest induced by coronary spasm on arrival at our hospital. There has been no case that prolonged spontaneous attack was confirmed in multi-vessels. This case demonstrates that persistent coronary spasm is lethal and an important cause of cardiopulmonary arrest even in young people. It is extremely important to detect patients with coronary spasm before the ischemic events associated with cardiopulmonary arrest occur.

[A case of MALT lymphoma simultaneously associated with gastric and pulmonary involvement].

A 52-year-old man had been treated by hemodialysis because of IgA nephropathy since 1994. Gastric MALT lymphoma was diagnosed in January 2007. Radiation therapy was performed for 4 weeks (40Gy) and the response was complete remission (CR) by September 2007. He was admitted to our hospital in February 2008 because of an abnormal chest shadow. Chest CT showed multiple cystic lesions with calcification and consolidation. Transbronchial lung biopsy from the area of consolidation (left S5) showed pulmonary invasion of small lymphoid cells. PCR analysis showed clonal rearrangement of the heavy chain of the immunoglobulin gene. Accordingly, MALT lymphoma was diagnosed. Rituximab infusion was performed, because CD20 immunostaining was positive and he had been treated by hemodialysis. The abnormal chest shadow was presented since gastric MALT lymphoma was diagnosed. We considered that MALT lymphoma occurred simultaneously in the stomach and lung.