Covalent immobilization of stem cell factor and stromal derived factor 1α for in vitro culture of hematopoietic progenitor cells

Hematopoietic stem cells (HSCs) are currently utilized in the treatment of blood diseases, but widespread application of HSC therapeutics has been hindered by the limited availability of HSCs. With a better understanding of the HSC microenvironment and the ability to precisely recapitulate its components, we may be able to gain control of HSC behavior. In this work we developed a novel, biomimetic PEG hydrogel material as a substrate for this purpose and tested its potential with an anchorage-independent hematopoietic cell line, 32D clone 3 cells. We immobilized a fibronectin-derived adhesive peptide sequence, RGDS; a cytokine critical in HSC self-renewal, stem cell factor (SCF); and a chemokine important in HSC homing and lodging, stromal derived factor 1α (SDF1α), onto the surfaces of poly(ethylene glycol) (PEG) hydrogels. To evaluate the system’s capabilities, we observed the effects of the biomolecules on 32D cell adhesion and morphology. We demonstrated that the incorporation of RGDS onto the surfaces promotes 32D cell adhesion in a dose-dependent fashion. We also observed an additive response in adhesion on surfaces with RGDS in combination with either SCF or SDF1α. In addition, the average cell area increased and circularity decreased on gel surfaces containing immobilized SCF or SDF1α, indicating enhanced cell spreading. By recapitulating aspects of the HSC microenvironment using a PEG hydrogel scaffold, we have shown the ability to control the adhesion and spreading of the 32D cells and demonstrated the potential of the system for the culture of primary hematopoietic cell populations.     

A case for antibiotic perturbation of the microbiota leading to allergy development

The use of antibiotics to treat pathogenic bacterial infections has been one of the greatest contributions to human health, yet antibiotic use also perturbs the communities of commensal and symbiotic bacteria that reside in the intestine of mammals. The microbiota are critical for normal immune development and for maintaining intestinal homeostasis, and disruption of the microbiota has been linked to the emergence of allergic disease both in humans and in animal models. The evidence and mechanisms for antibiotic-mediated disruptions leading to the onset of allergic disease at mucosal surfaces is discussed, as well as the future challenges for the field. A more complete understanding of the mechanisms by which the intestinal microbiota modulate allergic disease development will allow for interventions to counter the potentially adverse effects of antibiotic treatment on the microbiota.     

Comparison of the direct fluorescence assay and real-time polymerase chain reaction for the detection of influenza virus A and B in immunocompromised patients

OBJECTIVE:

This study evaluated the diagnostic performance of two methods for the detection of influenza virus in immunocompromised transplant patients.

METHODS:

A total of 475 respiratory samples, 236 from patients in a hematopoietic stem cell transplantation program and 239 from kidney transplant patients, were analyzed by a direct fluorescence assay and the Centers for Disease Control real-time polymerase chain reaction protocol for influenza A and B detection.

RESULTS:

Influenza detection using either method was 7.6% in the hematopoietic stem cell transplant group and 30.5% in the kidney transplant patient group. Influenza detection by real-time polymerase chain reaction yielded a higher positive rate compared with fluorescence than that reported by other studies, and this difference was more pronounced for influenza A. The fluorescence assay sensitivity, specificity, positive and negative predictive values, and kappa coefficient were 17.6%, 100%, 1, 0.83, and 0.256, respectively, and lower detection rates occurred in the kidney transplant patients.

CONCLUSIONS:

The real-time polymerase chain reaction performance and the associated turnaround time for a large number of samples support the choice of this method for use in different routine diagnostic settings and influenza surveillance in high-risk patients.     

HSCT后应用血清半乳甘露聚糖试验诊断侵袭性真菌感染113例报告

目的 探讨造血干细胞移植(HSCT)后采用血清半乳甘露聚糖(GM)试验对侵袭性真菌感染(IFI)的早期诊断价值.方法 回顾性分析113例HSCT受者的临床资料,根据诊断标准将受者分为确诊组、临床诊断组、拟诊组及非IFI组,应用统计软件分析GM试验的各项评价指标,发生IFI的危险因素,以及抗真菌治疗的疗效及其与GM试验的相关性.结果 113例受者中,GM试验阳性共有45例,总阳性率39.8％(45/113);确诊和临床诊断IFI的39例受者中,GM阳性31例(79.5％).GM试验的敏感性为79.5％,特异性为86.2％,假阳性率13.8％,假阴性率20.5％,阳性预测值79.5％,阴性预测值86.5％,诊断符合率83.5％,Youden指数0.66.另外,发现GVHD、粒细胞缺乏及既往有真菌感染病史是发生IFI的危险因素,而原发病为急性粒细胞性白血病和急性淋巴细胞性白血病两组IFI的发生率有显著性差异(P＜0.05).抗真菌治疗的总体有效率为52.7％,其中确诊和临床诊断IFI者的有效率为66.7％,治疗前GM阳性者在治疗后GM值有明显的降低(P＜0.05),且GM检测阳性者开始治疗的时间越早,治疗效果越好.结论 GM试验对HSCT后IFI具.有较好的早期诊断价值,动态监测GM水平变化可以作为评价抗真菌治疗效果的指标.     

非HLA基因单核苷酸多态性对造血干细胞移植后巨细胞病毒感染的影响

目的 探讨非HLA基因单核苷酸多态性(SNP)对造血干细胞移植后巨细胞病毒(CMV)感染的影响.方法 对2008年7月至2011年12月接受异基因造血干细胞移植的受者及其相应供者64例进行研究.采用聚合酶链反应-序列特异性寡核苷酸探针和测序方法检测髓过氧化物酶基因(MPO)、甘露糖结合凝集素基因(MBL)、CD14基因和血管紧张素转换酶(ACE)基因的SNP,结合CMV pp65检测结果,比较CMV阳性组和CMV阴性组ACE、CD14、MPO、MBL基因SNP的差异.结果 ACE 16内含子基因多态性分布:DD型14例(10.9％),ID型72例(56.3％),Ⅱ型42例(38.8％);CD14-159位基因多态性分布:CC型18例(14.1％),CT型81例(63.3％),TT型29例(22.7％);MPO-463位点基因多态性分布:G型100例(78.1％),A型2例(1.6％),GA型26例(20.3％);MBL启动子-550位基因多态性分布:H型28例(21.9％),HL型73例(57.0％),L型27例(21.1％);MBL启动子-221位基因多态性分布:Y型87例(68.0％),YX型38例(29.7％),X型3例(2.3％);MBL外显子1区基因多态性分布:A型94例(73.4％),AB型32例(25.0％),B型2例(1.6％).CMV阳性组和CMV阴性组供、受者ACE、CD14-159位点、MPO-463位点、MBL启动子-221以及外显子1区基因单核苷酸多态性相比较,差异均无统计学意义;但CMV阳性组供者MBL-550位点HL基因频率明显增高,与阴性组比较,差异有统计学意义.结论 供者MBL的单核苷酸多态性对造血干细胞移植后CMV感染有影响.     

异基因造血干细胞移植后淋巴组织增殖性疾病一例并文献复习

目的 探讨造血干细胞移植术后淋巴组织增殖性疾病(PTLD)的诊断和治疗.方法 回顾性分析1例异基因造血干细胞移植后PTLD的临床表现、诊断和治疗过程,并复习相关文献.结果 2007年1月至2012年11月196例造血干细胞移植后受者中有1例发生PTLD,发生率为0.5％.该例受者的临床表现不典型,主要表现为反复发热、多处淋巴结肿大和肺部多发性结节病变等,淋巴结活检提示弥漫大B细胞淋巴瘤.停用免疫抑制剂2个月后体温恢复正常,肿大的淋巴结和肺部结节病变完全消失.结论 PTLD是造血干细胞移植术后严重的并发症之一,具有独特的形态和临床特征.病因可能与EB病毒感染和免疫抑制有关,需经病理组织学检查确诊.治疗方法多样,减少免疫抑制剂用量可能是一种有效治疗措施.     

造血干细胞在心脏中的归巢与分化

利用造血干细胞治疗心脏损伤尤其是由退化、缺血和炎症引起的损伤已被认为是新近发展的重要治疗心脏病变的手段之一。造血干细胞在生理及病理条件下均能归巢于心肌,并能被动员至外周血且参与心脏的自稳态和组织维持。现就造血干细胞在心脏中归巢与分化的机制以及造血干细胞在治疗心脏病变中的应用进行简要综述。     

p21Cip restrains hippocampal neurogenesis and protects neuronal progenitors from apoptosis during acute systemic inflammation

Altered neurogenesis in adult hippocampus is implicated in cognition impairment and depression. Inflammation is a potent inhibitor of neurogenesis. The cyclin‐dependent kinase inhibitor p21^Cip1 (p21) restrains cell cycle progression and arrests the cell in the G1 phase. We recently showed that p21 is expressed in neuronal progenitors and regulates proliferation of these cells in the subgranular zone of the dentate gyrus of hippocampus where adult neurogenesis occurs. The current study suggests that p21 is induced in vivo in the hippocampus of WT mice in response to acute systemic inflammation caused by LPS injections, restrains neuronal progenitor proliferation and protects these cells from inflammation‐induced apoptosis. In intact p21^?/? hippocampus, neuronal progenitors proliferate more actively as assessed by BrdU incorporation, and give rise to increased number of DCX positive neuroblasts. However, when mice were treated with LPS, the number of neuroblasts decreased due to induced subgranular zone apoptosis. In vitro, differentiating Tuj‐1 positive neuroblasts isolated from p21^?/? hippocampus exhibited increased proliferation rate, measured by Ki‐67 staining, as compared to WT cells (p<0.05). In WT neuronal progenitors treated with IL‐6, the number of p21‐positive cells was increased (p<0.05), and this led to Tuj‐1⁺ cell proliferation restraint, whereas the number of proliferating GFAP⁺ astrocytes was increased ～ 2‐fold. Thus, when p21 is intact, inflammation might divert neuronal progenitors towards astrogliogenesis by inducing p21. At the same time, when p21 is lacking, no effects of IL‐6 on proliferation of Tuj‐1⁺ cells or GFAP⁺ cells are detected in differentiating p21^?/? neuronal progenitors. These results underscore the important role of p21 controlling hippocampal neuronal differentiation during inflammation. © 2013 Wiley Periodicals, Inc.     

脐血造血干/祖细胞体外扩增及移植动物模型分析

目的　探讨脐血造血干 /祖细胞体外扩增和体内重建造血的潜能。方法　利用造血干 /祖细胞培养、体外扩增、移植动物模型等技术 ,研究不同比密ficoll分离液分离的脐血造血干 /祖细胞的造血活性。结果　比密 1.0 6 4 g/ml分离液分离的 10 5个脐血MNC中 ,CFU GM集落数为 373± 2 89,BFU E为 12 1± 70。在G3(GM CSF和IL 3融合蛋白 )、IL 6、TPO(thrombopoietin)作用下 ,1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞在体外扩增 14d ,CFU GM扩增 5 2 .2倍。给经 8.5Gy致死剂量照射的小鼠输注 1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞 ,体内产生的脾结节 (CFU S)是输注 1.0 77g/ml分离液分离细胞的 2 .2倍。结论　比密 1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞 ,在体外具有较高的增殖、持续造血的能力及较强的体内造血重建潜能     

Incidence and risk factors of bacterial infections in children following autologous hematopoietic stem cell transplantation: Single‐center experience from Jordan

Bacterial infection is a serious sequela following AHSCT; however, limited data are available regarding pediatric recipients, especially in developing countries. We retrospectively analyzed the incidence and risk factors of bacterial infections during the first 100 days after AHSCT in children at KHCC in Amman, Jordan between January, 2005 and September, 2013. A total of 65 patients were identified, with median age of four yr (1–17). Forty‐seven patients (72.3%) had solid tumors and 18 (27.7%) had lymphoma. Bacterial infections were documented in 33 patients (50%), with a total of 63 episodes. Gram‐negative infection (57.1%) was more prevalent than Gram‐positive infection (38%). The risk of bacterial infections was higher among patients less than five yr of age (p = 0.028) and those who developed hypogammaglobulinemia requiring IVIG replacement (p = 0.001). Patients with solid tumors developed more bacterial infections compared to patients with lymphoma (p = 0.0057). No deaths were attributed to bacterial infection. Bacterial infection rate is high among recipients of AHSCT in Jordan with Gram‐negative bacteria being the most common.