Prevention of refractoriness and HLA-alloimmunization using filtered blood products

Depletion of leukocytes from all blood products may decrease the incidence of alloimmunization to HLA antigens present on the white cells and thus delay the onset of refractoriness to random donor platelet support. In order to test this hypothesis, 54 patients with hematologic malignancy or marrow aplasia were entered on a prospective randomized trial using cotton-wool filtration as a method of leukocyte depletion of red cell and platelet concentrates. Forty patients were considered evaluable; 20 patients received filtered products and 20 patients in the control group received standard unfiltered products. The filter was 99% efficient in removal of leukocytes (average number of WBC/platelet product, 6 X 10(6)). Platelet loss by this technique was 8%. Alloimmunization was assessed by detection of de novo formed lymphocytotoxic and platelet specific antibodies by microcytotoxicity test, Staph A protein radioimmunoassay, and solid phase red cell adherence test. In the group receiving filtered products, three of 20 (15%) patients developed lymphocytotoxic antibodies while ten of 20 (50%) patients in the control group developed cytotoxic antibodies (P = .01 by actuarial methods). Platelet antibodies were detected in seven of ten alloimmunized patients in the control group and three of three patients in the study group. Clinical evidence of refractoriness was seen in three of 20 patients in the filtered group and ten of 20 in the control group (P = .01 by actuarial methods). The cost of filtration was a fraction of the cost of a plateletpheresis product. Filtration appears to be an effective and economical method for reducing alloimmunization and clinical refractoriness to random donor platelets in patient receiving long-term transfusion support.     

Transforming growth factor beta selectively inhibits normal and leukemic human bone marrow cell growth in vitro

The effects of transforming growth factor beta 1 or beta 2 (TGF-beta 1 or -beta 2) on the in vitro proliferation and differentiation of normal and malignant human hematopoietic cells were studied. Both forms of TGF- beta suppressed both the normal cellular proliferation and colony formation induced by recombinant human interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). In the presence of GM-CSF or IL-3, optimal concentrations of TGF-beta (400 pmol/L) inhibited colony formation by erythroid (BFU-E), multipotential (CFU-GEMM), and granulocyte-macrophage (CFU-GM) progenitor cells by 90% to 100%, whereas granulocyte or monocyte cluster formation was not inhibited. In contrast, neither form of TGF-beta had any effect on G- CSF-induced hematopoiesis. The suppressive action appeared to be mediated directly by TGF-beta since antiproliferative responses were also observed in accessory cell-depleted bone marrow cells. In contrast to normal bone marrow cells, both GM- and G-CSF-induced proliferation of cells from patients with chronic myelogenous leukemia were suppressed in a dose-dependent manner by TGF-beta. Differential effects of TGF-beta on the proliferation of established leukemic lines were also observed since most cell lines of myelomonocytic nature studied were strongly inhibited where erythroid cell lines were either insensitive or poorly inhibited by TGF-beta. These results suggest that TGF-beta is an important modulator of human hematopoiesis that selectively regulates the growth of less mature hematopoietic cell populations with a high proliferative capacity as opposed to more differentiated cells, which are not affected by TGF-beta.     

Induced expression of c-fms in normal hematopoietic cells shows evidence for both conservation and lineage restriction of signal transduction in response to macrophage colony-stimulating factor

Retrovirus-mediated gene transfer was used to obtain expression of the macrophage colony-stimulating factor (MCSF) receptor, c-fms, on hematopoietic lineages that normally do not express this receptor. Cultures of murine fetal liver cells infected with the c-fms retrovirus developed erythroid colonies in cultures stimulated with M-CSF. However, these colonies were fewer and less hemoglobinized than colonies in parallel cultures stimulated by erythropoietin. Culture of isolated clones demonstrated a direct action of M-CSF on erythroid clones. Culture of c-fms retrovirus-infected adult murine bone marrow cells showed megakaryocyte and novel macrophage-megakaryocyte clones when stimulated by M-CSF. Culture of isolated clones again confirmed a direct action of M-CSF on megakaryocyte clones. In contrast, M-CSF stimulation of c-fms-infected granulocytes and granulocyte progenitor cells did not elicit proliferation, enhanced survival, or functional stimulation of granulocytes. These findings provide evidence for both conservation and lineage restriction of signal transduction in normal hematopoietic cells.     

缺血性脑卒中的A-S-C-O(表型)分类

背景和目的:国际5国脑血管病专家提出一种新的腩卒中亚型分类法,旨在介绍完整的"脑卒中表型"分类的新观念,该分类是包括脑卒中的病因和存在的所有病因相关的疾病,并将病因疾病按严重程度分成3级.     

Platelets express a membrane protein complex immunologically related to the fibroblast fibronectin receptor and distinct from GPIIb/IIIa

We have previously identified and characterized a membrane glycoprotein complex (GP150/135) that functions as fibronectin receptor (FN-R) in fibroblast adhesion. Here we report that an immunologically related protein complex is expressed at the surface of human platelets. Antibodies monospecific for the smaller subunit (GP135) of the fibroblast FN-R in fact specifically stained the platelet surface, as determined by FACS analysis, and reacted with a component of molecular weight (mol wt) 138,000 as shown in western blots of platelet membranes. Moreover, the same antibodies precipitated the 138,000 component together with a 160,000 protein, suggesting that the two molecules are associated in a supramolecular complex. A comparative analysis indicated that this protein complex is distinct from the GPIIb/IIIa complex, known to function as a receptor of wide specificity for fibrinogen, fibronectin, and von Willebrand factor. Differential extraction experiments revealed that the platelet 138,000 component is an integral membrane protein.     

维生素C及E联合作用对体外大鼠胚胎中脑神经细胞分化和增殖的影响

目的:观察维生素C,维生素E和维生素C 维生素E联合后对胚胎中脑神经细胞生长发育的影响。方法:实验于2006-03/04在江苏大学医学院研究中心细胞培养室完成。采用16d大鼠胚胎中脑神经细胞体外培养方法,观察不同剂量的维生素C(5,10,25,50μmol/L),维生素E(10,25,50,100μmol/L)和维生素C、维生素E联合作用(维生素C25μmol/L 维生素E50μmol/L,维生素C50μmol/L 维生素E100μmol/L),培养10d后收集细胞,并利用图像分析细胞形态的变化、蛋白质、丙二醛含量及超氧化物歧化酶活性指标。结果:①维生素C、维生素E和维生素C 维生素E联合能促进体外培养中脑神经细胞突起生长,集落数增多。②与正常对照组比较,维生素C10,25μmol/L组、维生素E10,25,50μmol/L组、维生素C25μmol/L 维生素E50μmol/L组神经细胞总蛋白相对含量明显增加。③与正常对照组比较,维生素C10,25μmol/L组、维生素E25,50μmol/L组、维生素C25μmol/L 维生素E50μmol/L组神经细胞超氧化物酶活性增加,丙二醛含量降低。④维生素C50μmol/L组、维生素E100μmol/L组和维生素C50μmol/L 维生素E100μmol/L组超氧化物酶活性低于正常对照组,丙二醛含量高于正常对照组。结论:维生素C、维生素E和维生素C 维生素E联合剂量在一定范围内能够明显提高中脑神经细胞的抗氧化能力,同时能促进胚胎中脑神经细胞分化和增殖作用。     

Spectrum and origin of phenylketonuria mutations in Spain

In order to characterize the molecular heterogeneity of phenylalanine hydroxylase deficiencies in the Spanish population, 37 PKU patients were initially screened for 16 known European mutations. For the remaining unidentified alleles, we used a combined strategy based on single strand conformation polymorphism analysis and DNA sequencing. Overall, a total of 15 different mutations were found in our sample, which account for 62% of the total mutant alleles. We also investigated the association between the mutations, haplotypes and variable number of tandem repeats described on the phenylalanine hydroxylase gene. In addition, we analyzed the geographical distribution in Spain of the two most prevalent mutations in our population: IVS10 and I65T.