体外分阶段共培养法扩增的脐血造血干/祖细胞移植于NOD/SCID小鼠的实验研究

研究用分阶段共培养法进行体外扩增的脐血造血干/祖细胞对NOD/SCID小鼠重建造血功能的作用,探讨新扩增技术体系对将来临床移植的可行性.分离脐血单个核细胞,分别用rhSCF+rhG-CSF+rhMDGF组合(非共培养组合)和rhSCF+rhG-CSF+rhMDGF+人骨髓间充质干细胞组合(共培养组合)进行脐血造血干/祖细胞的体外扩增,并对扩增细胞进行流式细胞术和细胞集落形成能力分析.在移植实验中,将经致死剂量射线照射后的NOD/SCID小鼠随机分为3组,每组10只.A组:每只移植8.5×106个用rhSCF+rhG-CSF+rhMDGF+人骨髓间充质干细胞组合扩增的细胞;B组:每只移植8.5×106个用rhSCF+rhG-CSF+rhMDGF组合扩增的细胞;C组:每只仅输注0.5 mL生理盐水.移植后定期眼眶底部采血,分析重建造血.12周后取存活小鼠骨髓,检测人特异Alu基因的存在率.实验结果表明,rhSCF+rhG-CSF+rhMDGF+人骨髓间充质干细胞组合的共培养法显著提高了造血干/祖细胞的扩增倍数,并且有利于造血干/祖细胞的自我更新和提高细胞集落形成能力.两种组合扩增的细胞移植小鼠12 d后,小鼠的白细胞类群开始回升,25 d后基本恢复到了基数水平.在45～55 d后小鼠细胞有明显的第2个恢复期,并且共培养组合扩增细胞移植的小鼠中第2次恢复明显快于非共培养组合.12周后在两种组合移植的小鼠中检测到人特异Alu序列片段的概率分别为87.5%(7/8)和88.9%(8/9).由此可推论,分阶段共培养扩增体系有效地提高了脐血造血干/祖细胞的扩增能力和重建造血能力.     

Transplantation and multiplier theorems for Fourier-Bessel expansions

Proved are weighted transplantation inequalities for Fourier-Bessel expansions. These extend known results on this subject by considering the largest possible range of parameters, allowing more weights and admitting a shift. The results are then used to produce a fairly general multiplier theorem with power weights for considered expansions. Also fractional integral results and conjugate function norm inequalities for these expansions are proved.

     

Manganese-Zinc Ferrites: Safe and Efficient Nanolabels for Cell Imaging and Tracking In Vivo

Manganese-zinc ferrite nanoparticles were synthesized by using a hydrothermal treatment, coated with silica, and then tested as efficient cellular labels for cell tracking, using magnetic resonance imaging (MRI) in vivo. A toxicity study was performed on rat mesenchymal stem cells and C6 glioblastoma cells. Adverse effects on viability and cell proliferation were observed at the highest concentration (0.55 mM) only; cell viability was not compromised at lower concentrations. Nanoparticle internalization was confirmed by transmission electron microscopy. The particles were found in membranous vesicles inside the cytoplasm. Although the metal content (0.42 pg Fe/cell) was lower compared to commercially available iron oxide nanoparticles, labeled cells reached a comparable relaxation rate R₂, owing to higher nanoparticle relaxivity. Cells from transgenic luciferase-positive rats were used for in vivo experiments. Labeled cells were transplanted into the muscles of non-bioluminescent rats and visualized by MRI. The cells produced a distinct hypointense signal in T₂- or T₂*-weighted MR images in vivo. Cell viability in vivo was verified by bioluminescence.     

脑海马结构研究进展

综述了海马结构研究的新进展,包括（１）磁共振成像海马结构体积测定;（２）微波辐射对海马的影响;（３）探讨主要由松果体分泌的褪黑素（ｍｅｌａｔｏｎｉｎ）与海马之间的功能关系;（４）在鼠海马内移植神经组织改善记忆减退;（５）铅、锌、铝离子对海马记忆的影响。     

EFFECTS OF 2-TUNNEL AND 3-TUNNEL FIXATION ON BIOMECHANICS OF TIBIOFEMORAL JOINT

基于正常膝关节4个屈曲角度(0°, 25°, 60°, 80°)下的磁共振(MR)图像数据, 建立正常/两隧道固定/三隧道固定内侧半月板移植术后的胫股关节模型. 对各屈曲角度下的4种模型分别施加单一轴向压载和压扭组合载荷进行有限元仿真, 得到各模型在2种载荷作用下的应力及位移分布. 提取关节软骨、半月板表面的等效应力以及半月板的最大位移进行对比分析, 得到内侧半月板移植术后两/三隧道固定对胫股关节中软骨及半月板的影响. 总体上讲内侧半月板移植中的三隧道固定要优于双隧道固定, 更利于胫股关节恢复正常的应力特性.     

Green's function, harmonic transplantation, and best Sobolev constant in spaces of constant curvature

We extend the method of harmonic transplantation from Euclidean domains to spaces of constant positive or negative curvature. To this end the structure of the Green's function of the corresponding Laplace-Beltrami operator is investigated. By means of isoperimetric inequalities we derive complementary estimates for its distribution function. We apply the method of harmonic transplantation to the question of whether the best Sobolev constant for the critical exponent is attained, i.e. whether there is an extremal function for the best Sobolev constant in spaces of constant curvature. A fairly complete answer is given, based on a concentration-compactness argument and a Pohozaev identity. The result depends on the curvature.

     

Assessment of ex vivo perfused liver health by Raman spectroscopy

Raman spectroscopy was applied in this research to monitor the overall health and degradation of porcine livers perfused ex vivo using the VasoWaveW® perfusion system. A novel Raman‐based diagnostic analysis was developed that enables near real‐time and label‐free monitoring of organ health during ex vivo perfusion designed to extend the useful life of the organ for transplantation. Multivariate statistical analysis of Raman spectra of organ perfusate fluid, using a combination of principal component analysis and linear discriminant analysis, proved to be an effective technique to assess the degradation properties of the livers. Three livers (with replicates) were perfused ex vivo under different pressures and temperatures and were compared with a 24‐h time‐course. Results indicated that perfusion pressure was a more significant factor in organ degradation than was temperature. In addition, a non‐linear degradation profile was identified for all three perfused livers, and this profile was different for individual livers, demonstrating the time‐dependent transition from its initial ‘healthy’ state towards a more ‘unhealthy’ degenerative state at 24 h. The Raman spectroscopy‐based approach described here has potential applications in perfusion and diagnostic instrumentation that can be used in near real‐time during organ transit and in operating rooms to help identify appropriately healthy organs for transplantation. Copyright © 2015 John Wiley & Sons, Ltd.     

Pros and Cons of the Cannabinoid System in Cancer: Focus on Hematological Malignancies

The endocannabinoid system (ECS) is a composite cell-signaling system that allows endogenous cannabinoid ligands to control cell functions through the interaction with cannabinoid receptors. Modifications of the ECS might contribute to the pathogenesis of different diseases, including cancers. However, the use of these compounds as antitumor agents remains debatable. Pre-clinical experimental studies have shown that cannabinoids (CBs) might be effective for the treatment of hematological malignancies, such as leukemia and lymphoma. Specifically, CBs may activate programmed cell death mechanisms, thus blocking cancer cell growth, and may modulate both autophagy and angiogenesis. Therefore, CBs may have significant anti-tumor effects in hematologic diseases and may synergistically act with chemotherapeutic agents, possibly also reducing chemoresistance. Moreover, targeting ECS might be considered as a novel approach for the management of graft versus host disease, thus reducing some symptoms such as anorexia, cachexia, fatigue, anxiety, depression, and neuropathic pain. The aim of the present review is to collect the state of the art of CBs effects on hematological tumors, thus focusing on the essential topics that might be useful before moving into the clinical practice.     

Low Pre-Transplant Caveolin-1 Serum Concentrations Are Associated with Acute Cellular Tubulointerstitial Rejection in Kidney Transplantation

Acute and chronic transplant rejections due to alloreactivity are essential contributors to graft loss. However, the strength of alloreactivity is biased by non-immunological factors such as ischemia reperfusion injury (IRI). Accordingly, protection from IRI could be favorable in terms of limiting graft rejection. Caveolin-1 (Cav-1) is part of the cell membrane and an important regulator of intracellular signaling. Cav-1 has been demonstrated to limit IRI and to promote the survival of a variety of cell types including renal cells under stress conditions. Accordingly, Cav-1 could also play a role in limiting anti-graft immune responses. Here, we evaluated a possible association between pre-transplant serum concentrations of Cav-1 and the occurrence of rejection during follow-up in a pilot study. Therefore, Cav-1-serum concentrations were analyzed in 91 patients at the time of kidney transplantation and compared to the incidence of acute and chronic rejection. Higher Cav-1 levels were associated with lower occurrence of acute cellular tubulointerstitial rejection episodes.