Thrombosed synthetic hemodialysis access fistulas: failure of fibrinolytic therapy

Seven episodes of acute thrombosis occurring in five patients with polytetrafluoroethylene dialysis fistulas were treated with local infusions of low-dose streptokinase. Bleeding from previous dialysis puncture sites necessitated stopping the infusion in six out of seven patients, although in one of these six, the graft reopened. The seventh patient had never been dialyzed through the graft and thrombolysis was achieved without incident. Surgery was avoided in only one patient. The authors contend that in these patients the risks of fibrinolytic therapy outweigh the benefits. Surgical thrombectomy, coupled with intraoperative angiography and possible angioplasty, is the preferred method of treating these patients. Venography prior to the creation of the fistula helps the surgeon avoid diseased vessels and may avert early failure of the fistula.     

山莨菪碱和蝙蝠葛碱对白三烯和PAF诱导的牛脑前动脉平滑肌细胞DNA合成的影响(英文)

白三烯和血小板活化因子在低于nmol浓度时就能刺激培养的牛脑前动脉平滑肌细胞的DNA合成,在10~(-7)mol/L时达最大刺激。LTB_4,LTD_4和PAF在10~(-7)mol/L时对上述细胞DNA合成的刺激率分别为32％,29％和77％。山莨菪碱和蝙蝠葛碱在10~(-7)～10~(-4)mol/L范围内呈剂量依赖性地抑制白三烯和血小板活化因子的上述作用。     

商陆多糖Ⅱ体外对小鼠脾细胞增殖及产生集落刺激因子的影响

用[³H]TdR参入法检测小鼠脾细胞增殖能力及产生集落刺激因子(colony stimulating factor. CSF)含量.证明商陆多糖Ⅱ(PAP-Ⅱ)在31～500 μg·m^-1范围内显著促进小鼠稗细胞增殖。PAP-Ⅱ,31～125 μg·ml^-1可剂量依赖性地促进Con A(1,2.8μg·ml^-1),LPS(3,10,30 μg·ml^-1)诱导的淋巴细胞细咆增殖,随着PAP-Ⅱ剂量加大,对丝裂原诱导的淋巴细胞增殖反呈抑制作用。PAP-Ⅱ。10～500μg·ml^-1呈剂量及时间依赖性地促进脾细胞产生CSF,其最适剂量为100 μg·ml^-1。最佳时间为5 d,提示PAP-Ⅱ能增强免疫及促进造血功能。     

Proliferation of human malignant hematopoietic cells in immunodeficient mice: suppression by antibody to pluripotent K-562 leukemia cells involves direct cytolysis and effector cells

Six human hematopoetic cell lines were successfully heterotransplanted into athymic (nude) and asplenic-athymic (lasat) neonatal mice. The tumors arising from leukemia and lymphoma cells could then be serially transplanted into adult nude mice. Seven days after the fourth serial mouse passage, each mouse was treated with goat immune gamma globulin against K-562 cells. One control group was treated similarly, but with nonimmune (normal) gamma globulin, while another control group was not treated. The goat gamma globulin was not toxic for nude and lasat mice, and the immune, but not the normal, gamma globulin suppressed local subcutaneous growth of myelosarcomas, lymphosarcomas, and Burkitt lymphoma cells. On the other hand, the growth of lung, breast, and prostatic carcinomas and a melanoma of human origin were not altered by the immune gamma globulin. Since suppression of cell growth occurred equally well in decomplemented mice, a complement-mediated cytotoxicity apparently cannot be considered as responsible for the abrogation. The Fab fragment of the immunoglobulin did not suppress the growth of the myelosarcomas. We conclude that antibody suppression of the in vivo proliferation was specific for malignant hematopoietic cells and that the Fc portion of IgG is necessary for in vivo cytolysis of leukemia cells. The most probable mechanisms are direct antibody cytolysis and antibody-dependent macrophage-mediated cytotoxicity.     

Excluding patients from transplant due to social support: Results from a national survey of transplant providers

Social support is used to determine transplant eligibility despite lack of an evidence base and vague regulatory guidance. It is unknown how many patients are disqualified from transplantation due to inadequate support, and whether providers feel confident using these subjective criteria to determine eligibility. Transplant providers (n = 551) from 202 centers estimated that, on average, 9.6% (standard deviation = 9.4) of patients evaluated in the prior year were excluded due to inadequate support. This varied significantly by United Network for Organ Sharing region (7.6%‐12.2%), and by center (21.7% among top quartile). Significantly more providers used social support in listing decisions than believed it ought to be used (86.3% vs 67.6%). Nearly 25% believed that using social support in listing determinations was unfair or were unsure; 67.3% felt it disproportionately impacted patients of low socioeconomic status. Overall, 42.4% were only somewhat or not at all confident using social support to determine transplant suitability. Compared to surgical/medical transplant providers, psychosocial providers had 2.13 greater odds of supporting the criteria (P = .03). Furthermore, 69.2% supported revised guidelines for use of social support in listing decisions. Social support criteria should be reconsidered in light of the limited evidence, potential for disparities, practice variation, low provider confidence, and desire for revised guidelines.