Further phenotypic characterization of the primitive lineage− CD34+CD38−CD90+CD45RA− hematopoietic stem cell/progenitor cell sub-population isolated from cord blood, mobilized peripheral blood and patients with chronic myelogenous leukemia

The most primitive hematopoietic stem cell (HSC)/progenitor cell (PC) population reported to date is characterized as being Lin−CD34+CD38−CD90+CD45R. We have a long-standing interest in comparing the characteristics of hematopoietic progenitor cell populations enriched from normal subjects and patients with chronic myelogenous leukemia (CML). In order to investigate further purification of HSCs and for potential targetable differences between the very primitive normal and CML stem/PCs, we have phenotypically compared the normal and CML Lin−CD34+CD38−CD90+CD45RA− HSC/PC populations. The additional antigens analyzed were HLA-DR, the receptor tyrosine kinases c-kit and Tie2, the interleukin-3 cytokine receptor, CD33 and the activation antigen CD69, the latter of which was recently reported to be selectively elevated in cell lines expressing the Bcr-Abl tyrosine kinase. Notably, we found a strikingly low percentage of cells from the HSC/PC sub-population isolated from CML patients that were found to express the c-kit receptor (<1%) compared with the percentages of HSC/PCs expressing the c-kitR isolated from umbilical cord blood (50%) and mobilized peripheral blood (10%). Surprisingly, Tie2 receptor expression within the HSC/PC subset was extremely low from both normal and CML samples. Using in vivo transplantation studies, we provide evidence that HLA-DR, c-kitR, Tie2 and IL-3R may not be suitable markers for further partitioning of HSCs from the Lin−CD34+CD38−CD90+CD45RA− sub-population

Comparison of Military and Civilian Methods for Determining Potentially Preventable Deaths: A Systematic Review.

IMPORTANCE: Military and civilian trauma experts initiated a collaborative effort to develop an integrated learning trauma system to reduce preventable morbidity and mortality. Because the Department of Defense does not currently have recommended guidelines and standard operating procedures to perform military preventable death reviews in a consistent manner, these performance improvement processes must be developed. OBJECTIVES: To compare military and civilian preventable death determination methods to understand the existing best practices for evaluating preventable death. EVIDENCE REVIEW: This systematic review followed the PRISMA reporting guidelines. English-language articles were searched from inception to February 15, 2017, using the following databases: MEDLINE (Ovid), Evidence-Based Medicine Reviews (Ovid), PubMed, CINAHL, and Google Scholar. Articles were initially screened for eligibility and excluded based on predetermined criteria. Articles reviewing only prehospital deaths, only inhospital deaths, or both were eligible for inclusion. Information on study characteristics was independently abstracted by 2 investigators. Reported are methodological factors affecting the reliability of preventable death studies and the preventable death rate, defined as the number of potentially preventable deaths divided by the total number of deaths within a specific patient population. FINDINGS: Fifty studies (8 military and 42 civilian) met the inclusion criteria. In total, 1598 of 6500 military deaths reviewed and 3346 of 19 108 civilian deaths reviewed were classified as potentially preventable. Among military studies, the preventable death rate ranged from 3.1% to 51.4%. Among civilian studies, the preventable death rate ranged from 2.5% to 85.3%. The high level of methodological heterogeneity regarding factors, such as preventable death definitions, review process, and determination criteria, hinders a meaningful quantitative comparison of preventable death rates. CONCLUSIONS AND RELEVANCE: The reliability of military and civilian preventable death studies is hindered by inconsistent definitions, incompatible criteria, and the overall heterogeneity in study methods. The complexity, inconsistency, and unpredictability of combat require unique considerations to perform a methodologically sound combat-related preventable death review. As the Department of Defense begins the process of developing recommended guidelines and standard operating procedures for performing military preventable death reviews, consideration must be given to the factors known to increase the risk of bias and poor reliability