Power bounded composition operators on spaces of analytic functions

We study the dynamical behaviour of composition operators defined on spaces of real analytic functions. We characterize when such operators are power bounded, i.e. when the orbits of all the elements are bounded. In this case this condition is equivalent to the composition operator being mean ergodic. In particular, we show that the composition operator is power bounded on the space of real analytic functions on Omega if and only if there is a basis of complex neighbourhoods U of Omega such that the operator is an endomorphism on the space of holomorphic functions on each U.The research of Bonet was partially supported by MEC and FEDER Project MTM2007-62643 and by GV Project Prometeo/2008/101. The research of Domanski was supported in years 2007-2010 by Ministry of Science and Higher Education, Poland, Grant no. NN201 2740 33. The authors are very indebted to F. Bracci for providing some information concerning complex dynamics. 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The role and potential of umbilical cord blood in an era of new therapies: a review

In light of pioneering findings in the 1980s and an estimation of more than 130 million global annual births, umbilical cord blood (UCB) is considered to be the most plentiful reservoir of cells and to have regenerative potential for many clinical applications. Although UCB is used mainly against blood disorders, the spectrum of diseases for which it provides effective therapy has been expanded to include non-hematopoietic conditions; UCB has also been used as source for regenerative cell therapy and immune modulation. Thus, collection and banking of UCB-derived cells have become a popular option. However, there are questions regarding the cost versus the benefits of UCB banking, and it also raises complex ethical and legal issues. This review discusses many issues surrounding the conservation of UCB-derived cells and the great potential and current clinical applications of UCB in an era of new therapies. In particular, we describe the practical issues inherent in UCB collection, processing, and long-term storage as well as the different types of ‘stem’ or progenitor cells circulating in UCB and their uses in multiple clinical settings. Given these considerations, the trend toward UCB will continue to provide growing assistance to health care worldwide

Clinical-grade generation of active NK cells from cord blood hematopoietic progenitor cells for immunotherapy using a closed-system culture process

Contains fulltext : 97724.pdf (publisher's version ) (Open Access)Natural killer (NK) cell-based adoptive immunotherapy is a promising treatment approach for many cancers. However, development of protocols that provide large numbers of functional NK cells produced under GMP conditions are required to facilitate clinical studies. In this study, we translated our cytokine-based culture protocol for ex vivo expansion of NK cells from umbilical cord blood (UCB) hematopoietic stem cells into a fully closed, large-scale, cell culture bioprocess. We optimized enrichment of CD34(+) cells from cryopreserved UCB units using the CliniMACS system followed by efficient expansion for 14 days in gas-permeable cell culture bags. Thereafter, expanded CD34(+) UCB cells could be reproducibly amplified and differentiated into CD56(+)CD3(-) NK cell products using bioreactors with a mean expansion of more than 2,000 fold and a purity of >90%. Moreover, expansion in the bioreactor yielded a clinically relevant dose of NK cells (mean: 2x10(9) NK cells), which display high expression of activating NK receptors and cytolytic activity against K562. Finally, we established a versatile closed washing procedure resulting in optimal reduction of medium, serum and cytokines used in the cell culture process without changes in phenotype and cytotoxic activity. These results demonstrate that large numbers of UCB stem cell-derived NK cell products for adoptive immunotherapy can be produced in closed, large-scale bioreactors for the use in clinical trials

Estimation of the overuse of preoperative chest X-rays according to "Choosing wisely", "No hacer", and "Essencial" initiatives: are they equally applicable and comparable?

Background: Overuse reduces the efficiency of healthcare systems and compromises patient safety. Different institutions have issued recommendations on the indication of preoperative chest X-rays, but the degree of compliance with these recommendations is unknown. This study investigates the frequency and characteristics of the inappropriateness of this practice. Methods: This is a descriptive observational study with analytical components, performed in a tertiary hospital in the Community of Madrid (Spain) between July 2018 and June 2019. The inappropriateness of preoperative chest X-ray tests was analyzed according to “Choosing Wisely”, “No Hacer” and “Essencial” initiatives and the cost associated with this practice was estimated in Relative Value and Monetary Units. Results: A total of 3449 preoperative chest X-ray tests were performed during the period of study. In total, 5.4% of them were unjustified according to the “No Hacer” recommendation and 73.3% according to “Choosing Wisely” and “Essencial” criteria, which would be equivalent to 5.6% and 11.8% of the interventions in which this test was unnecessary, respectively. One or more preoperative chest X-ray(s) were indicated in more than 20% of the interventions in which another chest X-ray had already been performed in the previous 3 months. A higher inappropriateness score was also recorded for interventions with an American Society of Anesthesiologists (ASA) grade ≥ III (16.5%). The Anesthesiology service obtained a lower inappropriateness score than other Petitioning Surgical Services (57.5% according to “Choosing Wisely” and “Essencial”; 4.1% according to “No Hacer”). Inappropriate indication of chest X-rays represents an annual cost of EUR 52,122.69 (170.1 Relative Value Units) according to “No Hacer” and EUR 3895.29 (2276.1 Relative Value Units) according to “Choosing Wisely” or “Essencial” criteria. Conclusions: There was wide variability between the recommendations that directly affected the degree of inappropriateness found, with the main reasons for inappropriateness being duplication of preoperative chest X-rays and the lack of consideration of the particularities of thoracic interventions. This inappropriateness implies a significant expense according to the applicable recommendations and therefore a high opportunity cost