三氧化二砷抑制体外培养小鼠气道成纤维细胞增殖及c-myc与c-sis表达

目的：探讨三氧化二砷 (As2O3))对体外培养的小鼠气道成纤维细胞 (FB)增殖及原癌基因c-myc与c-sis表达的影响。 方法： 按不同药物分7组，在体外培养的FB中分别加入浓度为0.25、0.5、1.0、2.0和4.0 μmol/L的As2O3，在1、3、5和7 d后用记数法观察FB生长情况，并用流式细胞仪（FCM）检测不同浓度药物 对各组FB增殖的影响及各组c-myc与c-sis的阳性表达率。 结果： 各种实验浓度的As2O3对FB均有抑制作用，并有时间剂量效应。流式细胞仪分析显示，随着浓度的增高，G1期细胞比例逐渐增高，G2/M期细胞比例降低，浓度为2.0和4.0 μmol/L的As2O3能显著抑制c-myc与c-sis的表达。 结论： As2O3能抑制FB的增生，其机理可能与其下调c-myc与c-sis的表达有关。     

人骨髓间质干细胞和嗅鞘细胞移植对大鼠急性脊髓损伤功能修复的比较研究

目的对比人骨髓基质细胞(BMSCs)与人胚嗅鞘细胞(OECs)移植对大鼠脊髓损伤功能修复的影响。方法将45只SD大鼠分成脊髓损伤后BMSCs移植组(BMSCs组)、OECs移植组(OECs组)和PBS对照组(PBS组),通过BBB评分、运动诱发电位(MEP)评估脊髓传导功能的改善状况,免疫组织化学方法检测移植细胞存活和分化情况,病理形态学方法观察组织结构修复情况。结果BMSCs组BBB评分高于OECs组(P<0.05);两细胞治疗组MEP潜伏期明显缩短(P<0.05);BMSCs组嗜银染色可见脊髓损伤近端有较多再生纤维向远端延伸,形成神经纤维束,而OECs组再生纤维较少;两种移植细胞均可在损伤处部分存活,BMSCs组可见BMSCs来源的细胞Nestin、NF、GFAP的阳性表达。结论BMSCs移植比OECs移植能更有效促进大鼠急性脊髓损伤修复。     

The instability of membrane markers expressed by human monocytes and macrophages in culture

Surface markers were tested on freshly isolated human monocytes and following their in vitro maturation to macrophages. The markers tested were HLA-DR antigens, receptors for the Fc of IgG and complement as well as membrane markers defined by monoclonal antibodies. The results revealed a dynamic expression of some of the markers on monocytes which was influenced by several variables. The expression of the markers was modulated by the presence of different sera, by treatment with lymphokines and interferon and following the in vitro maturation of monocytes to macrophages. The most unstable marker was found to be the HLA-DR, which was modulated by all these variables. The 63D3 was affected by different sera and culture supernatant, as well as following the maturation of monocytes to macrophages, but not by lymphokines and interferon. One of the markers, the Mac 120, was found to be relatively stable and did not change significantly following the maturation of monocytes to macrophages. The Fc and complement receptors were also stable in their expression under these conditions, but were probably partially blocked in the presence of human serum. These results indicated that at least some of the heterogeneity related to the monocyte population was probably not due to the occurrence of stable subsets of cells, but rather to reversible changes in marker expression.     

gp49B1 suppresses stem cell factor-induced mast cell activation-secretion and attendant inflammation in vivo

We report that gp49B1, a mast cell membrane receptor with two immunoreceptor tyrosine-based inhibitory motifs (ITIM), constitutively inhibits mast cell activation-secretion induced by stem cell factor (SCF), a tissue-derived cytokine that also regulates mast cell development. The intradermal injection of SCF into the ears of gp49B1 null (gp49B(-/-)) mice elicited approximately 4- and 2.5-fold more degranulating mast cells and tissue swelling caused by edema, respectively, than in gp49B(+/+) mice. SCF did not induce tissue swelling in mast cell-deficient mice, and the responsiveness of gp49B(-/-) mice to mast cell-associated amine and lipid mediators was unaltered. When gp49B(+/+) and gp49B(-/-) mice were pretreated with antagonists of the amines, SCF-induced tissue swelling was reduced by >90% and 60%, respectively, and it was reduced by >90% in both genotypes when a cysteinyl leukotriene receptor antagonist was also provided. Hence, the dominant contribution of secretory granule amines to SCF-induced tissue swelling is the result of gp49B1-mediated inhibition of the production of cysteinyl leukotrienes by mast cells. Our findings also provide the first example of an ITIM-bearing receptor that constitutively suppresses inflammation generated in vivo independently of the adaptive immune response by a receptor that signals through intrinsic tyrosine kinase activity rather than immunoreceptor tyrosine-based activation motifs.     

Intrarenal distribution of125I-polyvinyl pyrrolidone and51Cr-labelled red cells in hydropenic and polyuric rabbits

Summary The intrarenal volumes of distribution of¹²⁵I-polyvinyl pyrrolidone and⁵¹Cr-labelled red cells have been examined in rabbits under conditions of severe hydropenia and starvation-induced polyuria, and in rabbits under control conditions. The PVP space was significantly reduced, and the ratio [red cell space]:[red cell space + PVP space] significantly elevated, in the outer cortex of kidneys of hydropenic rabbits, and in the papilla of polyuric rabbits. It is suggested that the former may in some manner result from a reduction in the total cortical vascular space, whereas the latter reflects variations of medullary and appillary interstitial tonicity under these conditions.     

Development of patient derived organoids for cancer drug screening applications

Cancer is a disease characterised by abnormal cell growth that can invade or spread to other regions of the body. Organoids are three-dimensional ex vivo tissue cultures made from embryonic stem cells, induced pluripotent stem cells, progenitor cells or tissue that serve as a physiological model for cancer research. These are designed to recapitulate the in vivo properties of tumours. Importantly, effective recapitulation of the structure of tissues and function is believed to predict patient response, allowing for the creation of personalised therapy in a timely manner that may be used in the clinic. This Review discusses the pre-clinical model and different types of human organoids as models for the development of high throughput drug screening and also aims to highlight how organoids are shaping the future of cancer research.     

骨髓间充质干细胞分化为血管内皮细胞的实验研究

目的 :探讨骨髓间充质干细胞 (MSCs)自体移植后在扩张型心肌病(DCM)微环境中分化为血管内皮细胞的可行性。方法 :以日本大耳白兔为研究对象 ,分离培养扩增MSCs,盐酸阿霉素耳缘静脉注射复制兔DCM模型 ,将 5溴脱氧尿嘧啶 (BrdU)标记的MSCs移植到DCM心肌内 ,4周后观察移植细胞的增殖分化情况。结果 :细胞移植 4周后 ,实验组心肌内有BrdU标记的阳性细胞 ,有一部分参与组成新生血管 ,对照组中没有发现 ,且实验组毛细血管密度大于对照组 ,差异具有显著性 (P<0 .0 1)。结论 :MSCs自体移植到扩张型心肌病后可以分化为血管内皮细胞。     

骨髓间质干细胞体外分化为成骨细胞的实验研究

建立猪骨髓间质干细胞 (mesenchymalstemcells ,MSCs)体外分离培养方法。对猪MSCs体外分化为成骨细胞的能力进行研究。抽取猪骨髓 ,体外培养MSCs。取第二代MSCs ,以含有不同浓度的抗坏血酸、β -磷酸甘油、地塞米松及碱性成纤维细胞生长因子等条件培养基进行成骨细胞诱导分化。通过细胞形态变化 ,碱性磷酸酶染色及钙盐沉积对成骨细胞进行鉴定。结果表明MSC细胞形态由长梭形向多边形转变 ,ALP染色阳性 ,VonKossa染色阳性 ,经体外诱导分化后呈典型的成骨细胞样改变。猪骨髓MSCs可在体外长期、稳定培养 ,具有向成骨细胞分化的潜能 ,可以为骨组织工程研究提供较理想的细胞来源和动物模型。     

Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

Rabbit limbal corneal epithelial cells, corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth, arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion, amniotic membrane has good scaffold property, diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.     

Colocalization of glutamate and glycine in bipolar cell terminals of the human retina

Human retinae from surgical specimens rapidly fixed in a glutaraldehyde/formaldehyde mixture were subjected to postembedding, immunogold immunocytochemistry of glutamate and glycine, and subsequently analysed in an electron microscope. The two amino acids were visualised in the same tissue sections by the use of two different gold particle sizes. All bipolar cell perikarya and terminals showed significant glutamate labelling with mean gold particle densities 3–4 times higher than those of the retinal, non-neural pigment epithelial and Müller cells. Bipolar cell terminals displayed significantly higher glutamate labelling density than the bipolar cell bodies, as would be expected of glutamatergic neurons. A subpopulation of the glutamate-immunolabelled bipolar cell bodies (18%) and terminals (32%) also exhibited strong glycine labelling (7–8 times that of pigment epithelial and Müller cells). These glutamate-glycine positive terminals established contacts with amacrine cell processes and ganglion cell dendrites and were localised almost exclusively at between 44% and 88% depth of the inner plexiform layer, indicating that they belong to the ON cone bipolar system. This subpopulation of terminals was endowed with significantly higher glycine labelling density than the glycine positive bipolar cell bodies. These results show that human bipolar cell terminals colocalise glutamate and glycine and provide the first direct demonstration of an enrichment of these two amino acids in the same presynaptic element.