Identification of Bile Canalicular Cell Surface Antigen HAM.4 as Dipeptidyl Peptidase IV (DPPIV) and Characterization of Its Role in Hepatic Regeneration After Partial Hepatectomy in Rats

Dipeptidyl peptidase IV (DPPIV) has beenimplicated in the control of cell growth anddifferentiation. A rat hepatocyte membrane antigenrecognized by a monoclonal antibody (HAM.4) has now beenshown to be identical to DPPIV by immunoblot analysisand amino acid sequencing. The amounts of DPPIVimmunoreactive protein and enzymatic activity in serumincreased in a manner independent of de novo proteinsynthesis, and without any biochemical orimmunohistochemical changes in hepatic DPPIV, duringliver regeneration after partial hepatectomy in rats.DPPIV purified from serum by HAM.4 antibody-basedaffinity chromatography lacked the NH₂-terminal 36 aminoacids of the membrane-bound enzyme, suggesting thatproteolytic cleavage may mediate the release of DPPIVinto serum. No significant differences in therestoration of liver mass or in hepatic DNA synthesis were apparentbetween DPPIV-deficient and normal rats after partialhepatectomy, suggesting that DPPIV may not be essentialfor hepatic regeneration.     

加味补阳还五汤对周围神经损伤后神经机能恢复的实验研究

用加味补阳还五汤制剂给大鼠腓总神经损伤后的动物模型灌胃治疗,以观察该药物对周围神经损伤后神经机能恢复的作用。研究结果显示:用药组各观察周期运动神经传导速度均快于对照组(p<0.001);损伤后神经纤维传导速度的恢复率和伤肢的功能恢复用药组亦快于和早于对照组。     

针刺兔“足三里”穴不同层次神经纤维传入冲动实验研究

采用逆向碰撞技术,针刺兔“足三里”穴,探讨不同深度传入冲动纤维类型以及提插、捻转两种手法与神经冲动传导之间的关系。针刺兔“足三里”穴的浅、中、深三层,C类复合动作电位分别衰减25.03±7.27％,3.33±1.49％,3.18±1.45％,浅层与深层比较P<0.01,浅层与中层比较P<0.01;AB类复合动作电位分别衰减26.98±8.43％,20.31±5.55％,7.18±5.22％,浅层与深层比较P<0.05。可见C类和AB类纤维传入冲动在浅层占优势,古人提出穴位分三才补泻,从神经纤维在各层的分布偏重及传入冲动量的不同来分析,有其一定的理论基础及临床意义。针刺兔“足三里”穴,在C类纤维上进行提插与捻转手法比较,其冲动传入短时反应与长时反应的比例提插手法为1:3.8,捻转手法为1:2.8,但衰减值的比较由于观察例数少,未有统计学意义,似可认为提插手法的针后反应比捻转手法长,结合临床针感情况分析,提插手法疗效更佳。     

Skeletal Biology and Disease Modeling in Zebrafish

Zebrafish are teleosts (bony fish) that share with mammals a common ancestor belonging to the phylum Osteichthyes, from which their endoskeletal systems have been inherited. Indeed, teleosts and mammals have numerous genetically conserved features in terms of skeletal elements, ossification mechanisms, and bone matrix components in common. Yet differences related to bone morphology and function need to be considered when investigating zebrafish in skeletal research. In this review, we focus on zebrafish skeletal architecture with emphasis on the morphology of the vertebral column and associated anatomical structures. We provide an overview of the different ossification types and osseous cells in zebrafish and describe bone matrix composition at the microscopic tissue level with a focus on assessing mineralization. Processes of bone formation also strongly depend on loading in zebrafish, as we elaborate here. Furthermore, we illustrate the high regenerative capacity of zebrafish bones and present some of the technological advantages of using zebrafish as a model. We highlight zebrafish axial and fin skeleton patterning mechanisms, metabolic bone disease such as after immunosuppressive glucocorticoid treatment, as well as osteogenesis imperfecta (OI) and osteopetrosis research in zebrafish. We conclude with a view of why larval zebrafish xenografts are a powerful tool to study bone metastasis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

实验性面神经损伤后的神经再生速度

目的研究实验性面神经损伤后的再生速度。方法在立体定位下,面神经核团内注射标记蛋白前体结合闪烁计数技术研究豚鼠面神经损伤后的神经再生速度。结果用快、慢轴浆转运测出的外周面神经平均再生速度分别为2.84±0.12mm/d与3.16±0.08mm/d,再生延隔时间分别为2.67±0.11d与1.40±0.07d。结论研究得到豚鼠外周面神经损伤后的神经再生速度。     

Porous scaffold architecture guides tissue formation

Critical‐sized bone defect regeneration is a remaining clinical concern. Numerous scaffold‐based strategies are currently being investigated to enable in vivo bone defect healing. However, a deeper understanding of how a scaffold influences the tissue formation process and how this compares to endogenous bone formation or to regular fracture healing is missing. It is hypothesized that the porous scaffold architecture can serve as a guiding substrate to enable the formation of a structured fibrous network as a prerequirement for later bone formation. An ovine, tibial, 30‐mm critical‐sized defect is used as a model system to better understand the effect of the scaffold architecture on cell organization, fibrous tissue, and mineralized tissue formation mechanisms in vivo. Tissue regeneration patterns within two geometrically distinct macroscopic regions of a specific scaffold design, the scaffold wall and the endosteal cavity, are compared with tissue formation in an empty defect (negative control) and with cortical bone (positive control). Histology, backscattered electron imaging, scanning small‐angle X‐ray scattering, and nanoindentation are used to assess the morphology of fibrous and mineralized tissue, to measure the average mineral particle thickness and the degree of alignment, and to map the local elastic indentation modulus. The scaffold proves to function as a guiding substrate to the tissue formation process. It enables the arrangement of a structured fibrous tissue across the entire defect, which acts as a secondary supporting network for cells. Mineralization can then initiate along the fibrous network, resulting in bone ingrowth into a critical‐sized defect, although not in complete bridging of the defect. The fibrous network morphology, which in turn is guided by the scaffold architecture, influences the microstructure of the newly formed bone. These results allow a deeper understanding of the mode of mineral tissue formation and the way this is influenced by the scaffold architecture. © 2012 American Society for Bone and Mineral Research.     

小鸡再生听毛细胞及其突触连接的放射自显影

目的 采用光镜放射自显影（Ｌｉｇｈｔ ｍｉｃｒｏｓｃｏｐｉｃ ａｕｔｏｒａｄｉｏｇｒａｐｈｙ，ＬＭ－ＡＲＧ）及电镜放射自显像（Ｅｌｅｃｔｒｏｎ ｍｉｃｒｏｓｃｏｐｉｃ ａｕｔｏｒａｉｏｇｒａｐｈｙ，ＥＭ－ＡＲＧ）技术，观察不鸡再生听毛细胞及其突触连接的特征。方法 ７ｄ龄纯种伊莎鸡２０只，实验组（ｎ＝１４），连续皮下注射庆大霉素１０ｄ；对照组（ｎ＝６）。皮下注射生理盐水，用药第４ｄ开始注射氚村记胸腺