毁灭泰泽球虫(Tyzzeria perniciosa)的细胞化学研究 Ⅱ.核酸、蛋白质、碱性磷酸酶

本试验用组织化学技术对毁灭泰泽球虫生活史各阶段的几种细胞内含物进行了研究。试验表明,各期虫体内都存在 DNA 和蛋白质。滋养体,裂殖体,大配子和合子内存在 RNA,小配子体和小配子内未发现 RNA。裂殖体,大配子和小配子体内存在碱性磷酸酶(AKP)。     

盐度胁迫对锯缘青蟹体内腺苷三磷酸酶和磷酸酶活性的影响

采用酶学分析的方法研究了盐度（分别为5、15、25、35）胁迫下锯缘青蟹鳃、肌肉和肝胰腺中腺苷三磷酸酶和磷酸酶活性变化。结果表明，随着盐度降低，青蟹鳃中Na^＋，K^＋-ATPase、Ca^2＋，Mg^2＋-ATPase活性均升高，随着胁迫时间延长，Na^＋，K^＋-ATPase活性呈现不同的变化规律，且趋于平缓。青蟹肌肉中ACP活性随着盐度的升高而呈小幅度下降，而肝胰腺中ACP活性则呈小幅度升高，但各组之间差异不显著（P〉0.05）。不同胁迫时间同一盐度组青蟹肌肉中的ACP活性有升有降。青蟹肌肉、肝胰腺中AKP活性随着盐度升高而升高;随着胁迫时间延长，同一盐度组青蟹肌肉中AKP活性均呈升高趋势，肝胰腺中AKP活性有升有降。由此可见，盐度对青蟹生理生化影响显著。     

猪血清碱性磷酸酶(AKp)多态型的研究初报

采用聚丙烯酰胺凝胶电泳方法对我国4个地方猪品种(八眉猪,黑河猪,内江猪和荣昌猪)血清碱性磷酸酶(AKp)的遗传多态型进行了初步研究。发现猪血情 AKp 有 AA,BB,CC,AB 和 BC5种表现型,结果表明这些表现型分别受3个复等位基因 AKp~A,AKp~B 和 AKp~C 支配。计算了各品种AKp 基因频率和基因型频率,并对品种间的差异进行了分析和讨论。     

磁场处理对土壤磷酸酶活性的影响

本文研究了磁场处理后棕壤、黑土及白浆土中磷酸酶活性的变化。研究结果表明，磁处理对土壤的3种磷酸酶都有一定的激活作用，但以碱性磷酸酶的活性变化最明显。3种磷酸酶活性提高的大小顺序是：黑土中碱性磷酸酶＞酸性磷酸酶＞中性磷酸酶；棕壤和白浆土中碱性磷酸酶＞中性磷酸酶＞酸性磷酸酶。土壤水分对磷酸酶的磁处理效果影响不大。对于磷酸酶活性影响以＜100mT的低场强以及lrnin或10min的短时间处理效果较好。     

葡聚糖活化小鼠腹腔巨噬细胞的形态学观察

用葡聚糖(Dextran T 500)活化后,小鼠腹腔巨噬细胞(Mφ)胞体明显增大,细胞铺展明显,膜皱褶增多,细胞内吞噬体及溶酶体丰富,酸性磷酸酶(Acp)阳性颗粒增多。试验结果表明,用葡聚糖活化后的小鼠腹腔巨噬细胞,其形态和功能均呈现出极其活跃的状态。     

温度对黑豆萌发时酸性磷酸酯酶活力的影响研究

在不同温度下培养黑豆,提取不同萌发时期的酸性磷酸酯酶,利用福林-酚法测定其活力,研究温度对黑豆萌发时酸性磷酸酯酶活力的影响。结果表明,在15~35℃的温度范围内,黑豆在萌发时期,酸性磷酸酯酶的活力总体呈现出先上升、达到最大后又略微降低的现象。温度较高时,黑豆萌发较快,酸性磷酸酯酶达到最大酶活力所需时间较短;温度较低时,黑豆萌发过程中的最大酸性磷酸酯酶活力要低于较高温度下萌发的最大酶活力。     

基于骨骼重建机理的连续体结构仿生拓扑优化方法

骨重建是一种持续进行的新骨替代旧骨的过程,它通过具有骨吸收能力的破骨细胞和具有骨成形能力的成骨细胞来实现。在陆地脊椎动物中这两种细胞活动是严格平衡的,并且骨的拓扑形状是适应局部力学环境的。本文以Turing反应-扩散模型为基础,通过骨成形与骨吸收机理耦合建立了骨重建模型。该模型通过有限元方法和像素单元的添加和删除准则提出了连续体结构仿生拓扑优化计算方法,该方法将结构看成生长的骨骼,将寻找最优拓扑的过程比拟为骨骼的重建过程,应变能密度的均匀分布作为优化准则更新材料分布,直至达到一个平衡状态,并由此获得最优拓扑结构。最后通过典型的算例验证了所提方法的可行性和有效性。     

Characterization of Nucleated Cells From Equine Adipose Tissue and Bone Marrow Aspirate Processed for Point-of-Care Use

The objective of this study was to compare nucleated cell fractions and mesenchymal stromal cells (MSCs) from adipose tissue to bone marrow processed by a point-of-care device that are available for immediate implantation. A paired comparison using adipose and bone marrow from five horses was done. The number of nucleated cells, viability, total adherent cells on day 6 of culture and colony-forming unit fibroblasts (CFU-Fs) were determined. Gene expression for markers of stemness, adipogenic, chondrogenic, osteogenic lineage, and collagen formation was measured in total RNA isolated from adherent adipose and bone marrow cells. Day 6 adherent adipose-derived MSC was frozen briefly, whereas day 6 adherent bone marrow–derived MSC was passaged two additional times to obtain adequate cell numbers for chondrogenic, osteogenic, and adipogenic cell differentiation assays. The total cell count per gram was significantly greater for bone marrow, whereas total adherent cells per gram and the CFU-F per million nucleated cells on day 6 were significantly greater for the adipose. In undifferentiated adherent cells, relative gene expression for CD34, adipogenic, and chondrogenic markers and collagen II was significantly lower in the adipose-derived cells. Conversely, expression of collagen I was significantly higher in the undifferentiated adipose-derived cells. Cell density and total RNA were higher in differentiated adipogenic and osteogenic cultures of adipose cells and in chondrogenic cultures of bone marrow cells. This cell preparation method provides a stromal vascular fraction with a large proportion of multipotent MSCs. There are differences in the cells obtained from the two sources. This method can provide an adequate number of multipotent cells from adipose tissue for immediate implantation.     

Biological characteristics of mesenchymal stem cells from different resources in green fluorescent protein transgenic mice

AIM：To compare the biological characteristics, surface markers and multi-differentiation potential of the mesenchymal stem cells (MSCs) derived from the umbilical cord and bone marrow in the green fluorescent protein (GFP) transgenic mice. METHODS：Umbilical cord MSCs (UCMSCs) were isolated by collagen type II enzymatic digestion and bone marrow MSCs (BMSCs) were isolated by density gradient centrifugation. The growth of the 2 types of MSCs was observed under inverted microscope. The cell proliferation was detected by determining the growth curve and MTT assay. The Trypan blue method was performed to analyze the cell viability rate. The cell cycle and cell surface markers were measured by flow cytometry. The differentiation potentials of the 2 types of MSCs were tested by the differentiation kits toward adipocytes and osteoblasts. RESULTS：The UCMSCs attached to the culture surface 1 d after the isolation, and the cells showed spiral shape with notable growth and proliferation after 2 d of culture. After 3 d, the cell arrived sub-confluent and was ready for passage. BMSCs still showed circular shape and started to attach to the surface 4 d after culture. They formed the small colony shape only after 5 d with obvious proliferative potential. The cells became confluent 7 d after the culture. The original generation of cultivating UCMSCs growth curve was shown typically an “S” shape. But the BMSCs growth was slower than the UCMSCs. The cell proliferation was obvious for UC-MSCs in 3~5 d. BMSCs proliferated significantly only after 7 d. The viability rate arrived more than 96% for both types of MSCs. The cell cycle of both MSCs did not show significant difference (G0/G1 phases were above 85%, P>0.05). Both MSCs positively expressed CD44, CD90 and CD105 (60.7%±2.3%) but the expression of CD45, CD19, CD14 and CD79 was negative (less than 25.6%±4.8%, P>0.05). More than 90% of the MSCs from the umbilical cord and bone marrow differentiated towards the adipocytes and osteoblasts without significant difference (P<0.05). CONCLUSION：UCMSCs have stronger ability of proliferation and multi-directional differentiation potentials. UCMSCs in GFP transgenic mice as a high-quality tracer can serve for tracking the stem cells in vivo.     

Effects of Waller degenerative sciatic nerve segments on differentiation of BMSCs into SCs in rats

AIM:To observe the effects of Waller degenerative sciatic nerve segments on the ability of proliferation and secretion in rat bone marrow mesenchymal stem cells (BMSCs) as well as the differentiation of BMSCs into Schwann cells (SCs) under co-culture condition. METHODS:BMSCs were isolated from SD rats and identified by immunofluorescence. In Transwell co-culture system, the degenerative rat sciatic nerve segments and BMSCs were co-cultured in the Transwell inserts and well plates, respectively. The experiments were divided into 3 groups: group A, degenerative sciatic nerve segments co-cultured with BMSCs; group B, normal sciatic nerve segments co-cultured with BMSCs; group C, BMSCs cultured alone. The morphological changes of co-cultured BMSCs were observed under inverted phase-contrast microscope. The expression of S-100 in the BMSCs was tested by immunofluorescence staining after 7 d of co-culture. At 0, 1, 4, 7, 11 and 14 d after co-culture, BMSCs growth curve in each group were drawn by the method of cell counting, the expression of nerve growth factor (NGF) was detected by ELISA, and the mRNA expression of S-100 in the BMSCs was determined by real-time PCR. RESULTS:BMSCs were isolated and cultured successfully. The identification of BMSCs showed positive expression of CD29, CD44, and CD90. At 7 d after co-culture, the BMSCs in group A began retraction, became tapered with the processes and had SCs-like morphology, but most BMSCs in groups B and C showed no obvious morphological changes under inverted phase contrast microscope. The positive expression rates of S-100 in groups A, B, and C were 31.1%±2.9%, 16.2%±1.7%, and 0.42%±0.07%, respectively. There were significant differences of S-100 positive expression rates among 3 groups. The BMSCs growth curve of each group was similar to an "S" shape. From 4 d after co-culture, the BMSCs proliferation in group A were significantly faster than that in group B and group C. NGF in the supernatant of group A was increased in a time-dependent manner and reached the peak at 7 d after co-culture, then decreased gradually. NGF was also also increased in group B and group C, but the content of NGF was lower than that in group A. At 4, 7, 11 and 14 d of co-culture, NGF content was higher in group A than that in group B and group C, and a significant difference was also observed between group B and group C. The S-100 mRNA expression was significantly higher in group A than that in group B and group C at 4, 7, 11 and 14 d after co-culture (P<0.05). CONCLUSION: Waller degenerative sciatic nerve segments can effectively promote rat BMSCs proliferation and induce BMSCs to differentiate into SCs in vitro, and the growth factors secreted by degenerative sciatic nerve segments may be involved in the regulation of inducing BMSCs to differentiate into SCs.