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61.
Hartdorff Caroline M Frank Kneepkens CM van Dijk Alice EM Stok Anita Engels Michelle AH Gemke Reinoud JBJ Kindermann Angelika 《Tijdschrift voor kindergeneeskunde》2013,81(1):11-11
Tijdschrift voor Kindergeneeskunde - 相似文献
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64.
Uncoordinated expression of fibrinogen compared with thrombospondin and von Willebrand factor in maturing human megakaryocytes 总被引:7,自引:1,他引:7
Cramer EM; Debili N; Martin JF; Gladwin AM; Breton-Gorius J; Harrison P; Savidge GF; Vainchenker W 《Blood》1989,73(5):1123-1129
The localization of three known alpha-granule proteins, thrombospondin (TSP), von Willebrand factor (vWF), and fibrinogen (Fg) has been studied in human megakaryocytes (MK) by immunofluorescence and immunoelectron microscopy. For this study, highly purified populations of MK were prepared from human bone marrow either by counterflow centrifugal elutriation or by cell culture from normal subjects and from two patients with megakaryoblastic leukemia. In normal bone marrow immature MK, TSP, and vWF were observed in the Golgi-associated vesicles and in small immature alpha-granules; in mature MK, they were found in the matrix of the mature large alpha-granules. Surprisingly, Fg was detected neither in the Golgi area, nor in the small precursors of alpha-granules; it was only found in the mature alpha-granules but this labeling was generally weaker than in blood platelets. In order to confirm these differences between the expression of Fg and vWF or TSP additional studies were performed on cultured maturing MK: immunofluorescent and ultrastructural immunogold labeling confirmed that vWF appeared early in the maturation while the same immature MK were negative for Fg. In the late maturation stage, the three proteins were detected in the alpha-granules. In order to know whether Fg was lately synthesized or endocytosed from the outside medium, normal MK were grown in the presence of either normal or afibrinogenemic plasma, and normal serum. Fg was detected only in the alpha-granules of MK grown in normal plasma. Similar results were observed with malignant MK, whose maturation was independent of the culture conditions. In conclusion, this study brings immunocytochemical evidence that vWF and TSP are synthesized by immature MK, whereas Fg appears later in the MK alpha-granules and its expression is dependent of the presence of an exogenous Fg source. 相似文献
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66.
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
67.
Loss of expression of transforming growth factor beta in skin and skin tumors is associated with hyperproliferation and a high risk for malignant conversion. 总被引:12,自引:2,他引:12 下载免费PDF全文
68.
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
69.
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.
相似文献
70.
Using albumin and crystalloid as the only replacement fluids, the effect of partial plasma exchange on the removal and recovery of normal plasma constituents was studied. The results of 30 procedures on 10 individuals were evaluated. Four patterns of removal are described: reduction in the concentration of fibrinogen and C3 were greater than would be expected based upon the extent of the exchange, while IgG, IgM, cholesterol, alkaline phosphatase and SGPT were removed as expected. Reduction of serum glutamicoxalacetic transaminase (SGOT), lactate dehydrogenase (LDH), amylase, and creatine phosphokinase (CPK) averaged 17% less, and uric acid, calcium and K+ averaged 53% less than expected. Concentrations of HCO-3 and glucose did not change. The mean recovery for all constituents except fibrinogen, C3, cholesterol. IgG and IgM was near 100% at 48-72 hr postpheresis. The 72-hr recovery of fibrinogen and complement was 66% and 60%, respectively. Cholesterol recovery was also slow, requiring a minimum of 1 wk to reach prepheresis levels. Measured at a time when quantitative IgM levels were still reduced, alloantibody agglutinating activity (anti-A and anti-B) in a postpheresis sample exceeded prepheresis agglutinating activity. These data demonstrated that, depending upon quantity and frequency of pheresis, partial plasma exchange using albumin replacement may cause progressive marked reduction in concentrations of immunoglobulin, complement, fibrinogen, and cholesterol. Furthermore, newly synthesized antibody may have increased biologic activity. 相似文献