Copyright 2009 Advisory Plank Kaiser and Company Family members Foundation. All rights reserved.. The Times focuses on the Select Medical Corporation, ‘a publicly exchanged Pennsylvania company that operates 89 long-term hospitals, a lot more than any other company,’ but also points out that ‘more than 400 identical facilities. Handful of them have doctors on staff, & most are possessed by for-profit companies.’ ‘In 2007 and 2008, Select’s hospitals had been cited at a rate almost four times that of regular hospitals for significant violations of Medicare guidelines, according to an analysis by The New York Times.The physician researchers sought to identify glioblastoma subtype-specific cancer stem cells. Genetic analyses show that high-grade gliomas can be split into four subtypes: proneural, neural, mesenchymal and classic. This study demonstrates the mesenchymal subtype is the most aggressive subtype, that it has the poorest prognosis among affected individuals, and that tumor stem cells isolated from the mesenchymal subtype have significantly higher degrees of the enzyme ALDH1A3 compared with the proneural subtype. The findings, published in the Proceedings of the National Academy of Sciences recently, show that high levels of the enzyme drive tumor growth.