Computational study of scattering from healthy and diseased red blood cells

We present a comparative study of scattering from healthy red blood cells (RBCs) and diseased RBCs with deformed shapes. Scattering problems involving three-dimensional RBCs are formulated accurately with the electric and magnetic current combined- field integral equation and solved efficiently by the multilevel fast multipole algorithm. We compare scattering cross section values obtained for different RBC shapes and different orientations. In this way, we determine strict guidelines to distinguish deformed RBCs from healthy RBCs and to diagnose various diseases using scattering cross section values. The results may be useful for designing new and improved flow cytometry procedures. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3467493

Reprogramming of replicative senescence in hepatocellular carcinoma-derived cells

Tumor cells have the capacity to proliferate indefinitely that is qualified as replicative immortality. This ability contrasts with the intrinsic control of the number of cell divisions in human somatic tissues by a mechanism called replicative senescence. Replicative immortality is acquired by inactivation of p53 and p16(INK4a) genes and reactivation of hTERT gene expression. It is unknown whether the cancer cell replicative immortality is reversible. Here, we show the spontaneous induction of replicative senescence in p53-and p16(INK4a)-deficient hepatocellular carcinoma cells. This phenomenon is characterized with hTERT repression, telomere shortening, senescence arrest, and tumor suppression. SIP1 gene (ZFHX1B) is partly responsible for replicative senescence, because short hairpin RNA-mediated SIP1 inactivation released hTERT repression and rescued clonal hepatocellular carcinoma cells from senescence arrest