神经氨酸酶预处理对大鼠骨髓细胞分布及造血集落形成的影响

目的通过观察不同浓度的神经氨酸酶(neuraminidase,Neu)预处理供体骨髓细胞(donor bone marrow cells,dBMCs),经外周静脉注射后在受体内各主要组织器官的分布及对肝脏造血集落形成的影响,筛选出使dBMCs靶向性分布于肝脏的Neu最适浓度。方法以雄性SD大鼠为供体,Wistar雌性大鼠为受体。在dBMCs分布研究中,常规从雄性SD大鼠的股、胫骨制备dBMCs并用Neu处理。按Neu处理dBMCs的浓度将26只受体Wistar雌性大鼠分为4组,尾静脉注射99Tcm标记的dBMCs,5h后测定各组织器官的放射性活度。在造血集落形成研究中,受体Wistar雌性大鼠12只随机分为2组,尾静脉注射处理及未处理的dBMCs15d后,取受体各主要器官,行病理组织学检测,光镜下观察造血集落形成情况。结果在同一受体内,肝脏的dBMCs百分含量明显高于其他所测器官;以1·0U/ml浓度的Neu预处理时,受体肝脏内dBMCs百分含量高于对照组,差异显著(t=2·653,P=0·024),而肾脏内dBMCs百分含量低于对照组,差异显著(t=3·067,P=0·012),脾脏内dBMCs百分含量明显低于对照组,差异非常显著(t=3·265,P=0·009)。尾静脉注射15d后受体肝内可见造血集落形成,造血集落数量和形态上实验组与对照组无差别。结论在浓度为1·0U/ml时,神经氨酸酶预处理可增强骨髓细胞与肝脏的亲和性,使经外周静脉输注的骨髓细胞靶向性分布于受体肝脏内,但对肝脏内造血集落的形成无影响。

Contrast-enhanced sonography versus biopsy for the differential diagnosis of thrombosis in hepatocellular carcinoma patients

AIM:To clarify which method has accuracy:2nd gen-eration contrast-enhanced ultrasound or biopsy of portal vein thrombus in the differential diagnosis of portal vein thrombosis.METHODS:One hundred and eighty-six patients with hepatocellular carcinoma and portal vein thrombosis underwent in blinded fashion a 2nd generation contrast-enhanced ultrasound and biopsy of portal vein thrombus;both results were examined on the basis of the follow-up of patients compared to reference-standard.RESULTS:One hundred and eight patients completed the study.Benign thrombosis on 2nd generation contrast-enhanced ultrasound was characterised by progressive hypoenhancing of the thrombus;in malignant portal vein thrombosis there was a precocious homo-geneous enhancement of the thrombus.On follow-up there were 50 of 108 patients with benign thrombosis:all were correctly diagnosed by both methods.There were 58 of 108 patients with malignant thrombosis:amongst these,52 were correctly diagnosed by both methods,the remainder did not present malignant cells on portal vein thrombus biopsy and showed on 2nd generation contrast-enhanced ultrasound an inho-mogeneous enhancement pattern.A new biopsy during the follow-up,guided to the area of thrombus that showed up on 2nd generation contrast-enhanced ultra-sound,demonstrated an enhancing pattern indicating malignant cells.CONCLUSION:In patients with hepatocellular carcinoma complicated by portal vein thrombosis,2nd generation contrast-enhanced ultrasound of portal vein thrombus is very useful in assessing the benign or malignant nature of the thrombus.Puncture biopsy of thrombus is usually accurate but presents some sampling errors,so,when pathological results are required,2nd generation contrast-enhanced ultrasound could guide the sampling needle to the correct area of the thrombus.

五例胎盘血收集及CFU－GM祖细胞体外培养的初步探讨

本文探索了五例胎盘血（ＰＢ）的收集及位一单系祖细胞集落（ＣＦＵ－ＧＭ体外培养观察。结果表明：每个胎盘可收集约８０±ｍｌ血。ＣＦＵ－ＧＭ培养３天后集落开始生长。１４天后体积增大，细胞数增多，多数集落细胞＞４０个。提示ＰＢ中有丰富的ＣＦＵ－ＧＭ祖细胞。因此，本实验将为我们下一步临床应用ＰＢ治疗有关疾病或重建造血功能打下基础。

Recombinant human Flt3 ligand exerts both direct and indirect effects on hematopoiesis

OBJECTIVE: To investigate the direct effects of the Flt3 ligand (FL) on hematopoiesis, such as the stimulation of the formation of hematopoietic colonies and the proliferation of dendritic cells, as well as the indirect stimulation of hematopoiesis, especially via the proliferation of endothelial cells. METHODS: Mononuclear cells from human cord blood were plated in methylcellulose medium containing different cytokines to induce hematopoietic colony formation. Dendritic cells (DCs) were induced from the mononuclear cells with a cytokine cocktail with or without recombinant human soluble FL (rhFL; 100 ng/ml). The Flt3 receptors on the surface of a human microvascular endothelial cell line (ECV) were analyzed by flow cytometry. The proliferation of ECV stimulated by rhFL was measured with the microculture tetrazolium assay. The levels of FL, IL-6, IL-8, G-CSF and GM-CSF in the supernatant of ECV cultures were measured by enzyme linked immunoabsorbent assay (ELISA). RESULTS: rhFL stimulates colony formation from cord blood when used as a sole stimulant. FL in combination with other cytokines increased colony formation significantly. The number of DCs was approximately 2.5 times higher when rhFL was used. rhFL stimulates the proliferation of ECV on which Flt3 receptors are expressed. Furthermore, ECV secretes FL, IL-6, IL-8, G-CSF and GM-CSF, which were augmented by tumor necrosis factor-alpha and rhFL. CONCLUSIONS: rhFL enhances hematopoietic colony formation and DC proliferation from human cord blood cells. FL not only stimulates the proliferation of ECV, but is also secreted by ECV. FL may exert direct and indirect effects on hematopoiesis.

Multipotent mesenchymal stromal cells are fully permissive for human cytomegalovirus infection

Congenital human cytomegalovirus(HCMV) infection is a leading infectious cause of birth defects.Previous studies have reported birth defects with multiple organ maldevelopment in congenital HCMV-infected neonates. Multipotent mesenchymal stromal cells(MSCs) are a group of stem/progenitor cells that are multi-potent and can self-renew, and they play a vital role in multiorgan formation. Whether MSCs are susceptible to HCMV infection is unclear. In this study, MSCs were isolated from Wharton's jelly of the human umbilical cord and identified by their plastic adherence, surface marker pattern, and differentiation capacity. Then, the MSCs were infected with the HCMV Towne strain, and infection status was assessed via determination of viral entry,replication initiation, viral protein expression, and infectious virion release using western blotting,immunofluorescence assays, and plaque forming assays. The results indicate that the isolated MSCs were fully permissive for HCMV infection and provide a preliminary basis for understanding the pathogenesis of HCMV infection in non-nervous system diseases, including multi-organ malformation during fetal development.