Mapping differentiation pathways from hematopoietic stem cells using Flk2/Flt3 lineage tracing

Genetic fate-mapping approaches provide a unique opportunity to assess differentiation pathways under physiological conditions. We have recently employed a lineage tracing approach to define hematopoietic differentiation pathways in relation to expression of the tyrosine kinase receptor Flk2.¹ Based on our examination of reporter activity across all stem, progenitor and mature populations in our Flk2-Cre lineage model, we concluded that all mature blood lineages are derived through a Flk2⁺ intermediate, both at steady-state and under stress conditions. Here, we re-examine in depth our initial conclusions and perform additional experiments to test alternative options of lineage specification. Our data unequivocally support the conclusion that onset of Flk2 expression results in loss of self-renewal but preservation of multilineage differentiation potential. We discuss the implications of these data for defining stem cell identity and lineage potential among hematopoietic populations.     

新形势下加强医疗服务质量监管的路径选择

卫生服务质量包括公共卫生服务质量和医疗服务质量。其中,医疗服务质量直接关系到患者的生命与健康,是卫生服务的核心工作。目前,医疗服务市场”信息不对称”,因此,如何有效的监管医疗机构的服务质量成为政府的重要职责之一。本文在明确医疗服务质量监管内涵的基础上,结合我国监管现状,指出我国医疗服务领域所存在的监管主体单一、监管力量薄弱、监管法规有待完善、监管过程缺乏常态化、监管结果未能及时公开等方面的不足,并针对上述不足之处,提出四点政策建议：一是以政府为核心,培育多元监管主体;二是以信息化建设为平台,创新监管手段;三是以法规建设为重点,完善监管体系;四是加强监管结果的运用。     

A joint modeling approach for analyzing marker data in the presence of a terminal event

In many medical studies, markers are contingent on recurrent events and the cumulative markers are usually of interest. However, the recurrent event process is often interrupted by a dependent terminal event, such as death. In this article, we propose a joint modeling approach for analyzing marker data with informative recurrent and terminal events. This approach introduces a shared frailty to specify the explicit dependence structure among the markers, the recurrent, and terminal events. Estimation procedures are developed for the model parameters and the degree of dependence, and a prediction of the covariate‐specific cumulative markers is provided. The finite sample performance of the proposed estimators is examined through simulation studies. An application to a medical cost study of chronic heart failure patients from the University of Virginia Health System is illustrated.     

Quantum-like model of brain's functioning: decision making from decoherence

We present a quantum-like model of decision making in games of the Prisoner's Dilemma type. By this model the brain processes information by using representation of mental states in a complex Hilbert space. Driven by the master equation the mental state of a player, say Alice, approaches an equilibrium point in the space of density matrices (representing mental states). This equilibrium state determines Alice's mixed (i.e., probabilistic) strategy. We use a master equation in which quantum physics describes the process of decoherence as the result of interaction with environment. Thus our model is a model of thinking through decoherence of the initially pure mental state. Decoherence is induced by the interaction with memory and the external mental environment. We study (numerically) the dynamics of quantum entropy of Alice's mental state in the process of decision making. We also consider classical entropy corresponding to Alice's choices. We introduce a measure of Alice's diffidence as the difference between classical and quantum entropies of Alice's mental state. We see that (at least in our model example) diffidence decreases (approaching zero) in the process of decision making. Finally, we discuss the problem of neuronal realization of quantum-like dynamics in the brain; especially roles played by lateral prefrontal cortex or/and orbitofrontal cortex.     

关于干细胞临床产业化的一些思考

干细胞的基础研究和临床应用是近几年国内外的热点之一。但是因为没有产业化的明确途径,这个领域的产业化发展缓慢,很有可能像基因治疗和肿瘤疫苗的产业化一样无疾而终。本文探讨了干细胞治疗能够产业化之前需要解决的几个问题。从技术层面,我们比较了胚胎干细胞和成体干细胞,自体干细胞和异体干细胞的优缺点和国内外公司采取的一些途径。从政策方面,我们探讨了把干细胞治疗作为一种医疗技术还是一类医药产品的优缺点,比较了美国FDA和国内监管部门的相关政策,也提出了进一步的问题。最后,我们以美国FDA刚刚批准的Provenge为例,对细胞治疗和干细胞治疗的产业化提出了一些希望和想法。     

对医疗抢救立法中医疗特权相关问题的思考

医疗紧急情况下基于对患者的保护赋予的医疗特权,在病人自主理念深入的今天受到各种抵抗,而我国在医疗抢救立法方面对于医疗特权的法律法规标准并不统一,这也为医疗执业者的实践带来困难。探讨医疗特权行使的合法性标准,并提出构建第三方的社会支持系统或许能为弱势人群的医疗抢救提供更多的人道主义救援。     

临床路径与诊断相关组——预付款制度的关系深析

诊断相关组——预付款制度被越来越多的国家和地区应用到医疗管理领域中。中国经过多年的探索和研究,以新一轮医药卫生体制改革为契机,部分省市（如北京）的健康保健部门有计划地将诊断相关组——预付款制度应用到医疗费用管理中,然而对于诊断相关组——预付款制度与临床路径的关系仍然存在热议。着重研究诊断相关组——预付款制度与临床路径的内涵和实质,分析二者之间的内在联系,并在此基础上提出促进二者协调发展的建议。     

关于医疗纠纷调解协议的若干问题探析

快速、公正、科学、低成本地解决医疗纠纷是医疗纠纷处理的终极目标。《医疗事故处理条例》规定的3条解决医疗纠纷的途径难以做到定纷止争、案结事了。专门医疗纠纷调解委员会的成立为合法、公正、专业地化解各类医疗纠纷开辟了新的途径。关于医疗纠纷调解协议的性质、执行力、诉权等法律问题有待于进一步明晰。

     

实施临床医生医疗质量个体化管理的实践

以评价指标体系为基础,以监督检查、公示评价和针对性的教育培训为手段,对临床医生医疗质量实施个体化管理,提高全员质量意识和医院科学管理水平,各级医师责任意识得到强化,医疗质量得以持续改进。