Predicting hemolytic disease of the newborn: a comparison of the monocyte monolayer assay and the chemiluminescence test

The ability of the monocyte monolayer assay (MMA) and the chemiluminescence test (CLT) to predict the clinical significance of alloantibodies associated with hemolytic disease of the newborn (HDN) was assessed by the use of 22 well-characterized antisera– predominantly anti-D–from alloimmunized pregnant women. Seventeen sera were obtained before delivery from women whose infants were antigen positive for the antibody specificities identified in the maternal serum. With testing of these 17 sera by MMA, 10 results were in agreement with the presence or absence of HDN, but there were 5 false- positive and 2 false-negative results. With the CLT, 16 results were in agreement with the presence or absence of HDN, and there was 1 false- negative result. Five sera were obtained from women whose infants were antigen negative for the antibody specificities identified in the maternal serum. The CLT and the MMA were both subject to false-positive results with these sera. These results suggest that the CLT may be more valuable than the MMA as a noninvasive test for predicting the clinical significance of alloantibodies in HDN.     

由重组腺相关病毒1／2载体携带的LacZ报告基因在脐血间质干细胞中的表达

目的:观察由重组腺相关病毒1/2载体携带的LacZ报告基因在体外培养的脐血间质干细胞中的表达情况。方法:实验于2005-10/2006-02在上海交通大学附属新华医院科研中心完成。①以孕龄近60d的杂种妊娠犬的脐带血作为实验用脐血间质干细胞的标本来源。重组腺相关病毒1/2载体-lacZ基因(北京本原正阳基因技术有限公司)。②无菌条件下采集妊娠犬脐带血,置于预装有肝素的离心管中,与Hanks液1∶1混合均匀,叠加于相对密度为1.077的淋巴细胞分离液上,梯度离心分离后进行培养和扩增。③取第4代脐血间质干细胞,经胰酶消化后吹打成单细胞悬液,以5×104/孔接种于24孔板内,随机数字表法分为转染组20孔、空白对照组4孔。转染组将重组腺相关病毒1/2载体-lacZ报告基因(1×1012v.g.mL-1)用不含血清的IMDM培养液作系列滴度稀释,分为5个滴度,即感染复数分别为每个细胞1×102,1×103,1×104,1×105,1×106v.g,各感染复数均设4孔;空白对照组未加入病毒,只加入相同体积的不含血清的IMDM培养液。④转染72h后采用X-gal化学染色法进行检测,成功转染上LacZ基因的脐血间质干细胞其胞浆内会因合成半乳糖苷酶而呈阳性蓝染。每组样本随机选取5个视野,相差显微镜下计数半乳糖苷酶阳性细胞数,取均值即为LacZ基因细胞转染率。结果:①脐血间质干细胞生长情况及LacZ报告基因表达的检测:转染组病毒基因转染后未再见到明显的细胞增殖,转染72h后大部分细胞表达LacZ基因并合成半乳糖苷酶,X-gal染色呈蓝色,长梭形;4～6周后细胞形态趋向老化,长梭形逐渐变为宽扁形;8周后细胞均被蓝染,颜色明显较转染72h时深,细胞形态由长梭形变为不规则,明显老化。空白对照组细胞反应均为阴性。②LacZ报告基因细胞转染率测定结果:转染72h后,感染复数为每个细胞1×102v.g时,仅有少数细胞蓝染呈阳性;感染复数为每个细胞1×103,1×104,1×105,1×106v.g时,转染率分别为(43±5)%,(82±4)%,(95±4)%,(97±3)%。结论:体外培养的脐血间质干细胞能高效转染重组腺相关病毒1/2载体-lacZ报告基因,在一定感染复数范围内,细胞转染率随着感染复数的增加而升高。提示脐血间质干细胞是重组腺相关病毒1/2载体-lacZ报告基因转染的适宜靶细胞。     

生物膜与膨体聚四氟乙烯包裹治疗动脉瘤的效果对照

目的:比较生物膜与膨体聚四氟乙烯在动脉瘤包裹的远期治疗效果。方法:实验于2004-12/2006-10年在南方医院神经外科实验室与广东冠昊动物实验中心进行。取成年健康杂种犬10只,采用显微外科技术,将双侧的颈外静脉1.5cm嫁接双侧颈总动脉缺损1.5cm制作梭形动脉瘤模型20枚。左侧10枚应用生物膜(广东冠昊生物科技有限公司产品)包裹治疗,右侧10枚应用膨体聚四氟乙烯(美国戈尔公司周围血管补片)包裹治疗。术后第1,3,6,9,12个月行彩色多普勒超声血动态观察血流动力学变化,第12个月进行数字减影血管造影检测及解剖组织学观察。结果:10只犬全部进入结果分析。①血流动力学观察:生物膜包裹侧瘤腔消失、形态上趋于正常的颈总动脉,管腔均通畅,造影剂快速通过无滞留;血流恢复为层流,频谱特征与颈总动脉一致;1个月时生物膜与瘤壁存在微小间隙,3个月后间隙完全消失,12个月时血管顺应性、弹性与颈总动脉基本相匹配。膨体聚四氟乙烯包裹侧瘤腔消失、管腔通畅6枚,腔内为层流,频谱特征与颈总动脉相似,但速度明显高于远近端颈总动脉;瘤腔轻度缩窄,内壁出现轻度波状充盈缺损,包裹片长度轻度缩短;1个月和3个月各出现2枚血栓性闭塞,经主动脉弓照影不显像。6个月内膨体聚四氟乙烯与瘤壁存在清晰微小间隙,6个月后间隙消失。②组织学观察:生物膜包裹侧外表柔软类似颈总动脉,有较多毛细血管长入但维持原形,瘤腔内膜光滑无增厚,内皮细胞无增生、脱落,未见附壁血栓;生物膜与瘤壁融合、多层次降解,降解间隙内较多新生血管、组织长入,未见炎症细胞。膨体聚四氟乙烯外表僵硬、未见周围组织长入;内膜增厚、不光滑,内皮细胞核密集、部分脱落,薄层血栓附壁;4例见胶冻状长圆柱形杂色血栓。膨体聚四氟乙烯与瘤壁嵌入无降解,未看到明显的毛细血管长入;有极少的成纤维细胞伸入,散在的淋巴细胞浸润及少量巨噬细胞。结论:生物膜具有良好的理化性能与生物相容性,其效果优于膨体聚四氟乙烯,是动脉瘤包裹治疗的理想再生医学工程材料。     

Screening of blood donors for idiopathic CD4+ T-lymphocytopenia

BACKGROUND: The recent recognition of idiopathic CD4+ T-lymphocytopenia (ICL) had led to concern that an unknown immunodeficiency virus may be transmissible by transfusion. STUDY DESIGN AND METHODS: To evaluate the prevalence and significance of low CD4+ values among blood donors, CD4+ data on 2030 blood donors who were negative for antibody to human immunodeficiency virus type 1 (HIV-1) were compiled. Those with CD4+ values below ICL cutoffs (< 300 CD4+ T cells/microL, or < 20% CD4+ T cells) were recalled for follow-up investigations. Serial CD4+ data on 55 homosexual men who seroconverted during prospective follow-up and data on 139 anti-HIV-1-positive blood donors initially evaluated in 1986 were reviewed as well. RESULTS: Five seronegative donors (0.25%) had absolute CD4+ counts < 300 cells per microL and/or < 20 percent. On follow-up, all five donors had immunologic findings within normal ranges, lacked HIV risk factors, and tested negative for HIV types 1 and 2 and human T-lymphotropic virus type I and II infections by antibody and polymerase chain reaction assays. Four of five donors reported transient illness shortly after their low CD4+ count donations. The median interval from HIV-1 seroconversion to an initial CD4+ value below ICL CD4+ cutoffs was 63 months for infected homosexual men. Of 139 HIV-1-infected blood donors studied 1 to 2 years after seropositive donations, 34 (24%) had CD4+ counts < 300 cells per microL and/or < 20 percent. CONCLUSION: Low CD4+ counts are rare among anti- HIV-1-negative volunteer blood donors and are generally associated with transient illnesses. If any unknown virus progresses similarly to HIV- 1, CD4+ count donor screening would be a poor surrogate for its detection.