Localization of protein disulfide isomerase to the external surface of the platelet plasma membrane

Protein disulfide isomerase (PDI) is an enzyme that catalyzes the formation as well as the isomerization of disulfide bonds. In this study, antibodies against PDI were used to show PDI antigen on the platelet surface by indirect immunofluorescence microscopy and by flow cytometry. The platelets were not activated, as evidenced by the absence of staining by an antibody against P-selectin. Permeabilized platelets showed little cytosolic PDI by indirect immunofluorescence microscopy, suggesting that the majority of platelet PDI is localized to the platelet surface. PDI activity against "scrambled" RNase was shown with intact platelets. The activity was inhibited by inhibitors of PDI and by an antibody against PDI. Other blood cells showed little PDI. Platelet surface PDI may play a role in the various physiological and pathophysiologic processes in which platelets are involved.     

Efficacy and safety of caspofungin for treatment of invasive aspergillosis in patients refractory to or intolerant of conventional antifungal therapy

BACKGROUND: Invasive aspergillosis (IA) is an important cause of morbidity and mortality among immunocompromised patients. Echinocandins are novel antifungal molecules with in vitro and in vivo activity against Aspergillus species. METHODS: We investigated the efficacy and safety of caspofungin in the treatment of IA. Ninety patients with IA who were refractory to or intolerant of amphotericin B, lipid formulations of amphotericin B, or triazoles were enrolled to receive caspofungin. RESULTS: Efficacy was assessed for 83 patients who had infection consistent with definitions of IA and who received >or=1 dose of study drug. Common underlying conditions included hematologic malignancy (48% of patients), allogeneic blood and marrow transplantation (25% of patients), and solid-organ transplantation (11% of patients). Seventy-one patients (86%) were refractory to and 12 patients (14%) were intolerant of previous therapy. A favorable response to caspofungin therapy was observed in 37 (45%) of 83 patients, including 32 (50%) of 64 with pulmonary aspergillosis and 3 (23%) of 13 with disseminated aspergillosis. Two patients discontinued caspofungin therapy because of drug-related adverse events. Drug-related nephrotoxicity and hepatotoxicity occurred infrequently. CONCLUSION: Caspofungin demonstrated usefulness in the salvage treatment of IA.     

Comparison of CHOP versus CIOP in good prognosis younger patients with histologically aggressive non-Hodgkin lymphoma

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) has been the standard chemotherapy regimen used for diffuse large cell lymphomas for over 30 years. Idarubicin is a 4-demethoxy-anthracycline analogue of daunorubicin that has proven activity in non-Hodgkin lymphoma, and has been reported to cause less cardiotoxicity. We therefore initiated a randomised trial of standard dose CHOP versus CIOP (cyclophosphamide, idarubicin, vincristine and prednisolone), in which doxorubicin 50 mg/m2 was substituted by idarubicin 10 mg/m2, a dose thought to have equivalent anti-lymphoma activity. This trial was closed prematurely after 211 patients had completed therapy when a lower complete remission (CR) rate was noted in the CIOP arm. The formal results with long-term follow up are now reported. Overall response rate was 84% in the CHOP arm and 78% in the CIOP arm, CR rates were 70% and 52% respectively in all patients (P=0.013) and 73% and 52% respectively for the eligible patients (P=0.0084). At a median of 8 years follow-up, 4-year progression-free survival for all patients was 56% in the CHOP arm and 40% in the CIOP arm (P=0.0096). Overall survival for all patients was 65% in the CHOP arm and 56% in the CIOP arm (P=0.14). Results for eligible patients were comparable. CIOP containing idarubicin at a dose of 10 mg/m2 is clearly inferior to standard CHOP.     

干细胞因子基因cDNA克隆及其在造血干细胞中的表达

目的:克隆人干细胞因子基因cDNA,构建真核表达载体并转导脐带血造血干细胞,观察干细胞因子在造血干细胞中的表达,从而为脐血造血干细胞扩增及移植奠定实验基础。方法:实验于2005-09/12在承德医学院基础医学研究所和湖南师范大学医学院寄生虫病研究室完成。①实验材料:健康胎儿脐带由承德医学院附属医院提供,产妇均签署知情同意书;pcDNA3.1.大肠杆菌E.coliDH5α由本室保存;pUCm-T vector (promega公司);BamHⅠ,XbaⅠ(New England BioLabs公司):②实验方法:无菌收集胎儿脐带,胶原酶 胰蛋白酶 乙二胺四乙酸联合消化,分离培养人脐带内皮细胞。从上述含脐带内皮细胞的培养液中分离提取干细胞因子mRNA,用反转录-聚合酶链反应扩增干细胞因子cDNA.纯化的PCR产物与载体pUCm-T加入连接反应体系,构建及克隆pUCm-T/SCF质粒,其与pcDNA3.1分别进行BamHⅠ、XbaⅠ双酶切反应,产物经琼脂糖凝胶电泳后回收干细胞因子cDNA和pcDNA3.1片段,构建真核表达型载体pcDNA3.1/SCF。以密度梯度法 免疫磁珠法分离收集人脐血CD34~ 造血干细胞.导入pcDNA3.1/SCF,设立未转导对照组。③实验评估:转导后1～7 d检测两组细胞上清液中干细胞因子水平的表达。结果:①人于细胞因子基因cDNA克隆:扩增的人干细胞因子基因cDNA理论上应为690 bp,实际PCR产物经琼脂糖凝胶电泳后,紫外线下可见-预期大小的条带,证明干细胞因子mRNA提取成功,反转录合成的cDNA完整。②分泌型真核表达质粒pcDNA3.1/SCF的构建:BamHⅠ和XbaⅠ双酶切后电泳可见690 bp的插入片段,与干细胞因子基因序列相同,表明分泌型真核表达质粒pcDNA3.1/SCF构建成功。③脐血造血干细胞培养上清中的干细胞因子水平:培养第1～7天.转导pcDNA3.1/SCF的脐血造血干细胞上清中的干细胞因子表达水平均明显高于未转导对照组(P<0.01)。结论:成功克隆人干细胞因子基因cDNA,并构建了重组质粒pcDNA3.1/SCF,该质粒转导脐血造血干细胞后.能在短期内有效表达。     

Activities of four purified growth factors on highly enriched human hematopoietic progenitor cells

The activities of four purified human growth factors: biosynthetic (recombinant) granulocyte-macrophage colony-stimulating factor (GM- CSF); recombinant erythroid-potentiating activity (EPA); natural and recombinant pluripoietin (Ppo); and natural pluripoietin alpha (Ppo alpha), were compared on the growth of hematopoietic colonies from enriched populations of human marrow and blood progenitor cells. Conditioned medium from the Mo T cell line (MoCM) was used as a standard positive control. We found that activities of GM-CSF and Ppo alpha on the growth of hematopoietic colonies were indistinguishable; Ppo alpha is now believed to be identical to GM-CSF. Both factors were able to promote the growth of colonies derived from subpopulations of CFU-GM, BFU-E, and CFU-GEM. Colonies derived from CFU-GM and CFU-GEM in cultures stimulated by GM-CSF and Ppo alpha were much smaller than in cultures stimulated by MoCM. In contrast to previous reports in which less highly enriched progenitors were used as target cells, Ppo had no detectable activity on the growth of colonies derived from BFU-E or CFU- GEM but promoted the growth of a subpopulation of CFU-GM derived colonies. Ppo is now recognized to be identical to G-CSF. The GM colonies in cultures stimulated by G-CSF (Ppo) were much smaller than in cultures stimulated by MoCM. EPA had no detectable activity on either the size or number of colonies derived from CFU-GM, BFU-E, or CFU-GEM. Results from experiments using target cell populations of marrow fractions separated by velocity sedimentation and marrow populations following freezing suggested that GM-CSF (Ppo alpha) and G- CSF (Ppo) primarily affect the growth of relatively mature subpopulations of progenitor cells. It is clear from these results that additional factor(s) are present in MoCM that are necessary to stimulate CFU-GM, BFU-E, and CFU-GEM maximally in vitro.     

Identification and characterization of a high-affinity granulocyte- macrophage colony-stimulating factor receptor on primary rat oligodendrocytes

We previously showed the presence of receptors for granulocyte- macrophage colony-stimulating factor (GM-CSF) on tumor tissues and tumor cell lines that are derived from the neural crest. To determine whether normal neural cells express functional GM-CSF receptors, we isolated and analyzed primary rat brain cells, including microglia, astrocytes, and oligodendrocytes. Scatchard analysis of equilibrium binding of 125I-GM-CSF to primary rat oligodendrocytes showed an average of 1,110 GM-CSF binding sites per cell, with a kd of 20 pmol/L. In six separate experiments, no specific binding was detectable on the astrocyte population. Microglia were used in competitive binding experiments with oligodendrocytes, and addition of microglia did not increase the specific binding of labeled ligand to oligodendrocytes. In dose-response assays, we measured 3H-thymidine uptake in rat oligodendrocytes, microglia and control murine 32D cells stimulated with various concentrations of GM-CSF. Over concentration ranges of 0.025 to 1000 pmol/L, cell proliferation and peak 3H-thymidine incorporation was observed at approximately 30 pmol/L for both the control cells and the oligodendrocytes. However, the microglial cells did not proliferate in response to GM-CSF. These data indicate the presence of a functional receptor for GM-CSF on primary rat oligodendrocytes, and suggest that hematopoietic growth factors such as GM-CSF may play a role in nerve cell development, function, or response to injury.