Using a mouse model of breast cancer,
we tested the importance of the senescence response in solid cancer and identified genetic pathways regulating this response. Mammary expression of activated Ras led to the formation of senescent cellular foci in a majority of mice. Deletion of the p19(ARF), p53, or p21(WAF1) tumor suppressors but not p16(lNK4a) prevented senescence and permitted tumorigenesis. Id1 has been implicated in the control of senescence in vitro, and elevated expression of Id1 is found in a number of solid cancers, so we tested whether overexpression of Id1 regulates senescence in vivo. Although overexpression of Id1 in the mammary epithelium was not sufficient for tumorigenesis, mice with expression of both Id1 and activated Ras developed metastatic cancer. These tumors expressed high levels of p(19Arf), GDC-0941 in vivo p53, and p21(Waf1), demonstrating that Id1 acts find more to make cells refractory to p21(Waf1)-dependent cell cycle arrest. Inactivation of the conditional Id1 allele in established tumors led to widespread senescence
within 10 days, tumor growth arrest, and tumor regression in 40% of mice. Mice in which Id1 expression was inactivated also exhibited greatly reduced pulmonary metastatic load. These data demonstrate that established tumors remain sensitive to senescence and that Id1 may be a valuable target for therapy.”
“We report a new strategy towards the control of carbon nanotube (CNT) structure and continuous fibre formation using a floating catalyst direct spinning CVD process. Combretastatin A4 purchase In the procedures used to date, a sulphur promoter
precursor is added to significantly enhance the rate of CNT formation in the floating catalyst synthesis. Within the reaction zone, the rapidly grown nanotubes self-assemble into bundles, followed by their continuous spinning into fibres, yarns, films or tapes. In this paper we demonstrate a catalyst control strategy in the floating catalyst system, where the CNT formation process is independent of the presence of a promoter but leads to successful spinning of the macroscopic carbon nanotube assemblies with specific morphology, high purity (Raman D/G 0.03) and very narrow diameter range (0.8-2.5 nm). This can be achieved by the control of catalyst precursor decomposition and subsequent formation of homogeneous nano-sized catalyst particles.”
“To investigate the hyphal-form transition of Trichosporon asahii (T. asahii) of different sources under different temperatures, media and cultural times; eleven T. asahii strains were isolated and maintained in RPMI-1640 medium, YPD liquid medium, Tween yeast bouillon (TYB) medium and 50% (v/v) fetal calf serum (FBS) medium independently to induce the hyphal growth. Culture was performed at 15, 25 and 37 degrees C for 1, 2, 3, 6, 12 and 24 h and the hyphal formation (growth) rate was calculated. The mean hyphal formation rate was (0.15 +/- 0.42)% at 15, (5.75 +/- 3.48)% at 25 degrees C and (33.81 +/- 15.39)% at 37 degrees C (P<0.