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91.
Extended long-term culture reveals a highly quiescent and primitive human hematopoietic progenitor population 总被引:5,自引:17,他引:5
Long-term culture-initiating cells (LTC-IC) are hematopoietic progenitors able to generate colony-forming unit-cells (CFU) after 5 to 8 weeks (35 to 60 days) of culture on bone marrow (BM) stroma and represent the most primitive progenitors currently detectable in vitro. We have recently reported that long-term cultures initiated with CD34+CD38- cells from BM or cord blood are able to continue generating CFU for at least 100 days, ie, beyond the standard LTC-IC period. In this report, single-cell cultures from cord blood and retroviral marking of cord blood and BM were used to study whether the subpopulation of CD34+CD38- cells able to generate CFU beyond 60 days ("extended long-term culture-initiating cells" or ELTC-IC) are functionally distinct from LTC-IC in terms of timing of initial clonal proliferation and generative capacity. All cord blood LTC-IC formed clones of greater than 50 cells by day 30. In contrast, cord blood ELTC- IC proliferated later in culture, 50% forming clones after day 30. Although efficient retroviral marking of LTC-IC was seen (25% to 45%), marking of ELTC-IC was inefficient (< 1%), consistent with a more quiescent progenitor population. There was a positive correlation between time of clonal proliferation and generative capacity. ELTC-IC generated threefold to fourfold more progeny than did LTC-IC (P < .002). These studies show that there is a functional hierarchy of progenitors in long-term culture which correlates with their level of quiescence. By extending the LTC-IC assay, a more primitive progenitor may be studied that may be functionally closer to the human long-term repopulation stem cell in vivo. 相似文献
92.
Aortic annulus and root characteristics in severe aortic stenosis due to bicuspid aortic valve and tricuspid aortic valves: Implications for transcatheter aortic valve therapies
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93.
Comparison of acute elastic recoil between the SAPIEN‐XT and SAPIEN valves in transfemoral–transcatheter aortic valve replacement
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Shikhar Agarwal MD MPH Olcay Aksoy MD Muhammad Hammadah MD Kanhaiya Lal Poddar MD Rishi Puri MD Lars G. Svensson MD PhD Amar Krishnaswamy MD E. Murat Tuzcu MD FACC Samir R. Kapadia MD FACC 《Catheterization and cardiovascular interventions》2015,85(3):490-496
- Complex arch anatomy (type 2, type 3) and bovine configuration were identified in 34.4% and 20.5% of carotid stent patients, respectively.
- Catheter manipulation time (CMT), rather than arch complexity per se, was the only independent predictor of adverse events after carotid stenting.
- Careful attention to patient selection, preprocedural planning, and stent technique are important to ensure success.
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Francis L. Counselman MD Chair Marc A. Borenstein MD Carey D. Chisholm MD Michael L. Epter DO Sorabh Khandelwal MD Chadd K. Kraus DO MPH Samuel D. Luber MD MPH Catherine A. Marco MD Susan B. Promes MD Gillian Schmitz MD for the EM Model Review Task Force Julia N. Keehbauch for the American Board of Emergency Medicine 《Academic emergency medicine》2014,21(5):574-598
In 2001, “The Model of the Clinical Practice of Emergency Medicine” was first published. This document, the first of its kind, was the result of an extensive practice analysis of emergency department (ED) visits and several expert panels, overseen by representatives from six collaborating professional organizations (the American Board of Emergency Medicine, the American College of Emergency Physicians, the Society for Academic Emergency Medicine, the Residency Review Committee for Emergency Medicine, the Council of Emergency Medicine Residency Directors, and the Emergency Medicine Residents' Association). Every 2 years, the document is reviewed by these organizations to identify practice changes, incorporate new evidence, and identify perceived deficiencies. For this revision, a seventh organization was included, the American Academy of Emergency Medicine. 相似文献
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Jeremias A Dusa C Forudi F Jacobsen DW Vince DG Nissen SE Tuzcu EM 《International journal of cardiology》2004,95(2-3):255-260
BACKGROUND: Vascular inflammation generating oxidized metabolites at the site of balloon angioplasty is believed to play a major role in the process of vessel restenosis. Glutathione, the most potent endogenous antioxidant, may have protective effects after angioplasty by suppressing local inflammatory response. The aim of the study was to test the hypothesis that oral administration of N-acetyl-cysteine (NAC, a precursor of glutathione) reduces restenosis in an animal model of vascular injury. METHODS: In New Zealand white rabbits, an atherosclerotic lesion was introduced to both iliac arteries by air denudation of the endothelium while feeding the animals a high-cholesterol diet. After 4 weeks, all animals underwent balloon angioplasty of the endothelial injury site and half of the group was started on 150 mg/kg NAC per day. Quantitative angiography was performed prior to the angioplasty and at the final procedure 3 weeks later. Glutathione levels were determined in all animals at the beginning and the end of the study. RESULTS: Although not statistically significant, plasma glutathione level increased in the NAC group from 32.4+/-4.4 to 39.7+/-11.6 micromol/l, while it decreased from 30.6+/-13.4 to 28.3+/-11.5 micromol/l in the control group. During the study period, 6 vessels occluded leaving 14 vessels for analysis. Quantitative angiographic analyses prior to angioplasty and at follow-up showed no significant difference with respect to stenosis progression between the groups. Measurement of neointima formation by histology showed also no significant difference between the groups (0.175+/-0.040 mm(2) vs. 0.123+/-0.075 mm(2)), neither did intimal macrophage count as a marker for local inflammatory response. CONCLUSIONS: Despite an increase in plasma glutathione level in the NAC-treated group, there was no reduction in lesion progression after balloon angioplasty. Therefore, NAC does not seem to prevent restenosis after vascular intervention in this animal model. 相似文献
100.
al-Shahi R; Mason JC; Rao R; Hurd C; Thompson EM; Haskard DO; Davies KA 《Rheumatology (Oxford, England)》1997,36(7):794-798
Thrombocytopenia in patients with acute systemic lupus erythematosus (SLE)
frequently presents the clinician with considerable diagnostic and
therapeutic difficulties. In this Grand Round, we present a 48-yr- old
woman with a 7 yr history of lupus, who presented with acute proliferative
glomerulonephritis and nephrotic syndrome, pneumonia, profound
hypocomplementaemia and a severe microangiopathic haemolytic anaemia with
associated thrombocytopenia. Her thrombocytopenia proved initially
refractory to conventional immunosuppressive therapy, and corticosteroids,
and resolved only with plasma exchange and repeated fresh frozen plasma
infusions. Serological testing revealed high-titre antinuclear antibodies
(ANA) and markedly raised antibodies to double- stranded (ds) DNA, but no
significant elevation in anticardiolipin antibodies. Platelet-associated
IgG and IgM and antibodies to the CD36 glycoprotein antigen, expressed on
platelets and endothelium, were detected in the serum. We address some of
the difficult diagnostic and management issues raised by this complex
patient and the possible immunopathological links between antibodies to
CD36, immune-mediated red cell destruction, thrombocytopenia and thrombotic
microangiopathic haemolytic anaemia.
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