斑马鱼血液疾病模型及应用

血液发育是一个复杂有序且保守的过程,由多种转录因子和信号通路协同调控,任何环节的失调都可能引起血液系统发育或功能缺陷,导致血液疾病的发生。斑马鱼(Daniorerio)造血过程及分子调控机制与哺乳动物高度保守。应用斑马鱼模拟致病因子的异常变化构建相关血液疾病模型,为探究疾病发生机制、肿瘤发生发展可视化研究及高通量化学筛选提供了有力的工具。本文概述了斑马鱼血液疾病模型及其应用,这些疾病模型不仅有助于完善对血液系统病理生理学、血液疾病发生分子机制的认识,也为临床相关恶性血液疾病的治疗提供了新思路。     

斑马鱼在抗肿瘤血管生成研究中的应用

近年来,斑马鱼作为一种新的模式生物,在胚胎的分子发育机制、疾病模型的构建以及药物筛选等研究中受到了广泛重视。随着先进的基因诱导技术和共聚焦显微观察技术的发展,斑马鱼已经在抗肿瘤血管生成药物研究中得到广泛应用。就斑马鱼在抗肿瘤血管生成药物筛选及其在肿瘤血管生成机制方面研究的应用作一综述。     

二甲双胍对斑马鱼骨骼发育及损伤修复的机制研究

二甲双胍(metformin,MET)是治疗糖尿病的一线药物,对骨骼疾病也有一定的治疗效果,但具体作用机制尚不明确.本研究利用斑马鱼(Danio rerio)构建骨质疏松模型,通过荧光观察、骨骼染色、半定量PCR、原位杂交及ELISA等技术方法,探究MET对斑马鱼骨骼发育及损伤修复的作用机制.首先通过胚胎致死率、骨骼矿...     

斑马鱼研究走向生物医学

1972年美国俄勒冈大学George Streisinger教授开始研究斑马鱼(Danio rerio)至今, 斑马鱼以其独特的优点, 已经成为现代遗传学、发育生物学研究的重要模式动物。世界范围内斑马鱼研究群体的工作已奠定了较为完善的胚胎学、分子遗传学研究基础, 并且斑马鱼已被应用于开发人类重大疾病模型和药物筛选平台, 取得了许多有价值的研究成果。文章简述了斑马鱼成为模式动物的历史, 侧重介绍了业已建立的白血病、黑色素瘤、感染免疫疾病、神经疾病等斑马鱼模型, 以及利用斑马鱼进行小分子化合物/药物筛选和研发的现状。斑马鱼研究向生物医学方向的拓展, 必将为人类理解重大疾病发生机制、寻找疾病治疗方法, 为维护人类卫生、健康做出贡献。     

血管内皮生长因子及其受体在斑马鱼胚胎血管发育中的作用

血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种多功能的细胞因子,其主要作用是促进血管内皮细胞增殖和增加血管通透性,是肿瘤及正常组织血管生成的中心调控因素。以VEGF为靶点的肿瘤血管靶向性治疗成为近几年肿瘤治疗的新途径。斑马鱼作为一种重要的模式生物,被广泛用于胚胎的分子发育机制、疾病模型的构建以及药物筛选等研究中。文章对斑马鱼作为心血管系统研究模型的优势及其血管研究方法做一阐述,重点对斑马鱼VEGF及其受体的最新研究进展做了介绍,并展望了其发展前景。     

斑马鱼肝纤维化动物模型研究进展

斑马鱼因胚胎光学透明、发育快以及药物可以通过皮肤和鳃渗入体内等原因，被广泛应用于肝疾病的相关研究。肝纤维化(hepatic fibrosis, HF)是指由各种致病因子所致的肝内结缔组织异常增生的一种病理生理变化，许多慢性肝病均可引起HF。由于斑马鱼HF发生所涉及的信号传导机制与人类相似，目前已成功构建斑马鱼肝纤维化模型。本文论述国内外斑马鱼HF模型研究的相关成果和肝纤维化治疗药物筛选的现状，旨在为探索肝纤维化发病机制、寻找HF治疗药物及斑马鱼HF模型的合理应用提供指导。     

斑马鱼在新药发现中的应用

在过去20年里,斑马鱼已成为一种重要的模式脊椎动物,在发育、遗传、免疫、肿瘤和毒理等诸多研究领域中被广泛应用。近年来,斑马鱼作为活体模型越来越多地应用于某些生物学过程的药物筛选。通过斑马鱼初步筛选,在药物研发初期可确定化合物的生物学活性、毒性以及副作用等。最近的研究还发现,斑马鱼不仅用于新药筛选,还可用于药物结构的优化。本文重点介绍斑马鱼在新药发现中的应用。     

模式动物斑马鱼在神经系统疾病研究中的应用

近年来,斑马鱼作为一种新型模式动物被广泛地应用于发育学、遗传学、行为学和分子生物学等研究领域。其具有繁殖能力强、发育迅速且同步、体外受精和幼体透明等生物学和形态学特点,经广泛培养和筛选突变品种,目前斑马鱼品系资源丰富。与其他非脊椎模式动物相比,它与人类有更高的同源性。本文主要介绍斑马鱼作为一种理想的模式动物,结合其特殊的行为学检测手段和分子生物学特点,在研究神经系统疾病的发病机制、构建疾病模型和相应药物筛选等方面的应用。     

斑马鱼模型在药物筛选中的应用

斑马鱼具有子代数量多、体外受精、胚胎透明、可以做大规模遗传突变筛选等生物学特性, 因此成为一种良好的脊椎动物模式生物。随着研究的深入, 斑马鱼不仅应用于遗传学和发育生物学研究, 而且拓展和延伸到疾病模型和药物筛选领域。作为一种整体动物模型, 斑马鱼能够全面地检测评估化合物的活性和副作用, 实现高内涵筛选。近年来, 科学家们不断地发展出新的斑马鱼疾病模型和新的筛选技术, 并找到了一批活性化合物。这些化合物大多数在哺乳动物模型中也有相似的效果, 其中前列腺素E2(dmPGE2)和来氟米特(Leflunomide)已经进入临床实验, 分别用来促进脐带血细胞移植后的增殖和治疗黑素瘤。这些成果显示了斑马鱼模型很适合用于药物筛选。文章概括介绍了斑马鱼模型的特点和近年来在疾病模型和药物筛选方面的进展, 希望能够帮助人们了解斑马鱼在新药研发中的应用, 并开展基于斑马鱼模型的药物筛选。     

以斑马鱼为模式动物研究器官的发育与再生

斑马鱼因其受精卵体外发育、胚胎透明、具有较强的再生能力以及适于大规模遗传筛选的优势, 成为研究脊椎动物器官发育与再生的新兴模式动物。通过数十年的探索, 科研工作者已经在斑马鱼中建立了一套成熟的研究方法, 并对斑马鱼胚胎发育早期的细胞命运决定和分化、组织器官的形态建成以及受损后的再生过程有了初步的认识。近年来, 随着遗传筛选技术的大规模开展和活体成像技术在斑马鱼中的深入应用, 许多在小鼠等模式动物中悬而未决的问题开始得到充分解答。随着研究的不断深化和技术的不断更新, 以斑马鱼为模式动物, 对脊椎动物器官发育与再生的研究将会更加深入, 相关的调控机制也会被逐步探明, 从而为临床相关疾病的防治提供富有价值的参考。文章通过对近年来发表的文章进行回顾, 总结了斑马鱼作为模式动物研究中枢神经系统、肝脏和胰腺、血液细胞和血管等重要器官早期发育过程及其调控机制的进展, 并阐述了以斑马鱼研究尾鳍、心脏、肝脏等器官再生的优势和初步发现。     

PIXE technique for calcium analysis of human bone

The determination of calcium content in human bone tissue is very useful in metabolic diseases of bone, such as renal osteodystrophy, osteoporosis, hyperparathyroidism, and osteomalacia of diverse etiology. The PIXE technique allows calcium to be directly determined in bioptic tissue sections properly, sampled for histological optical and/or electron microscopy examination. Bone semithin sections (3 μm thick, 4×4 mm² dimensions), cut by ultramicrotome and deposited onto polyvinyl acetate films, underwent PIXE analysis using the CISE set-up. Histomorphometric (after standard staining), evaluation of calcified bone volume (CBV) in absolute value allows calcium density to be determined. A total of nine bone biopsies were analyzed (three sections each) obtaining values ranging between 352 and 482, with an average value of 421.5±15.3 (M±SE) μg/μL, in good agreement with literature data (obtained by AAS technique on dissected bone samples). The aim of this paper is to emphasize the usefulness, of combined PIXE and histomorphometric techniques for the study of calcium content in bone tissue in both healthy and diseased bones.     

微流控芯片在乳腺癌骨转移研究中的应用

乳腺癌骨转移患者死亡率高达70%～80%,目前缺乏有效的治疗药物.微流控芯片技术能够有效模拟骨组织的生化和生物物理微环境,便捷地实现模拟骨微环境中乳腺癌骨转移的研究,这将为探索乳腺癌骨转移的细胞和分子机制、进而进行抗乳腺癌骨转移药物高通量筛选提供有价值的技术方法和平台.本综述简要介绍了乳腺癌骨转移的分子机制和治疗药物研究现状,详细阐述了乳腺癌骨转移的微流控芯片模型,分析了基于微流控芯片技术进行抗乳腺癌骨转移药物高通量筛选的优势和挑战,旨在为乳腺癌骨转移机制研究和药物筛选提供参考.     

新型迭形接骨板的临床应用

目的：改进骨折接骨扳内固定技术．观察新型迭形接骨板临床效果。方法：选择四肢长管骨骨折患者165例(上肢骨折26例,下肢骨折139例),均采用新型迭形接骨板施行骨折内固定手术。结果：手术后平均随访1年4个月(5年7个月～51天),除5例(占3％)出现并发症外,其余骨折均愈合良好,很少发现接骨板和螺钉断裂、折弯和松动情况。结论：与传统接骨板比较,新型迭形接骨板结构设计新颖,力学原理独特,临床效果满意,并发症少,较好地改进了四肢长管骨(尤其是下肢)骨折接骨板内固定技术,值得推荐。     

Study on the Microstructure of Human Articular Cartilage/Bone Interface

For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope (SEM), histological sections and MicroCT were used to observe, measure and model the microstructure of cartilage/bone interface. The results showed that the cartilage/bone interface is in a hierarchical structure which is composed of four different tissue layers. The interlocking of hyaline cartilage and calcified cartilage and that of calcified cartilage and subchondral bone are in the manner of “protrusion-pore” with average diameter of 17.0 μm and 34.1 μm respectively. In addition, the cancellous bone under the cartilage is also formed by four layer hierarchical structure, and the adjacent layers are connected by bone trabecula in the shape of H, I and Y, forming a complex interwoven network structure. Finally, the simplified structure model of the cartilage/bone interface was proposed according to the natural articular cartilage/bone interface. The simplified model is a 4-layer gradient biomimetic structure, which corresponds to four different tissues of natural cartilage/bone interface. The results of this work would be beneficial to the design of bionic scaffold for the tissue engineering of articular cartilage/bone.     

Chronology of fusion of the primary and secondary ossification centers in the human sacrum and age estimation in child and adolescent skeletons

Little is known about fusion times of the primary and secondary centers of ossification in the sacrum, particularly from dry bone observations. In this study, the timing of union of these centers was studied in a sample of modern Portuguese skeletons (90 females and 101 males) between the ages of 0 and 30 years, taken from the Lisbon documented skeletal collection. A three‐stage scheme was used to assess fusion status between ossification centers as unfused, partially fused and completely fused. Posterior probability tables of age, given a certain stage of fusion, were calculated for most anatomical locations studied using both reference and uniform priors. Partial union of primary centers of ossification was observed from 1 to 8 years of age and partial union of secondary centers of ossification was observed from 15 to 21 years of age. The first primary centers of ossification to complete fusion are the neural arch with the centrum of the fifth sacral vertebrae and the last are the costal element with the centrum of the first sacral vertebra. The annular and sacroiliac epiphyses are the first, among the secondary centers of ossification observed, to complete fusion, after which the lateral margin fuses. This study offers information on timing of fusion of diverse locations in the developing sacrum useful for age estimation of complete or fragmented immature human skeletal remains and fills an important gap in the literature, by adding to previously published times of fusion of primary and secondary ossification centers in this sample. Am J Phys Anthropol 153:214–225, 2014. © 2013 Wiley Periodicals, Inc.     

Effect of bioadctive glass templates on osteoblast proliferation and in vitro synthesis of bone-like tissue

Using in vitro synthesifzed bone tissue with cells aspirated fpom the patient's marrow is an appealing idea to avoid the profound limitations of biological of biologiaal and synthetic grafts. Procedures to synthesize bone tiqsue on vitro primapily relied on seeding various subqtpates with cellq that have osteogenia capacity in culture. It should be noted that in an in vitro system, msteoppogenitor cells, as well as bone themselves an papidiy change their phenotype, hence the substrate needs to promote the expression or the bone cell Phenotype. Furthermore, it needs to provide a template for bone deposition while gradually resorbing once bone tissue has been laid down. This paper presents initial evidence that optimally combines the requirements of the ideal template for in vitro synthesis of bone tissue. When made in popous dorm, and conditioned to detelop a bone-like surface prior to being seeded with pluripoteltial cells capable of expressing the osteoblastic phenotype, these templates lead to expeditious and a undalt in vitro synthesis of extracellular matrix with most important characteristics of bone tissue.     

The effect of restriction of dietary calcium on trabecular and cortical bone mineral density in the rats

This study aimed to investigate effects of restricted calcium intake on cortical and trabecular bone density in white rats. Low Ca diet was fed for six weeks, and bone density and bone metabolism parameters were assessed in blood. This study was carried out on 12 male white rats aged 12 weeks (Sprague-Dawley; SD). These rats were bred for 1 week and randomly assigned to the standard calcium diet group (SCa group, n = 6) and the low calcium diet group (LCa group; n = 6). The SCa group was given a modified AIN-93M mineral mix (with 0.5% Ca), which was made by adding calcium to a standard AIN93 diet, and the LCa Group was fed a modified AIN-93 Mineral mix (with 0.1% Ca). Femoral BMD and BMC were measured by DEXA in each rat. After trabecular bone was separated from cortical bone, volumetric bone mineral density (vBMD) was measured using pQCT. Serum Ca and P levels were measured as parameters of bone metabolism, and S-ALP, S-TrACP and-Dpd levels were also measured. The results revealed no significant differences in weight, growth rate, feed consumption and feed efficiency between the two groups before and after calcium-restricted diet (p > .05). No significant differences were also observed in bone length and bone mass between the two groups (p > .05). Although bilateral femoral BMDs were not significantly different between the two groups, bilateral femoral BMCs significantly decreased in the LCa group, compared with the SCa group (p = .023, p = .047). Bilateral cortical MDs were not significantly different between the two groups, either. However, trabecular BMD significantly decreased in the LCa group, compared with the SCa group (p = .041). U-Dpd and S-TrACP levels significantly declined in the LCa group, compared to the SCa group (p = .039, p = .010). There were no significant differences in serum Ca and P levels between the two groups (p > .05). However, a significant decrease in urinary Ca level (p = .001) and a significant increase in urinary P (p = .001) were observed in the LCa group, compared to the Sca group. These findings described that six-week low calcium diet led to decreased trabecular bone density, reduced urinary excretion of Ca and increased urinary excretion of P. As a result, Ca hemeostasis can be maintained.     

Validation of Bone Conversion in Osteoconductive and Osteoinductive Bone Substitutes

Bone reconstruction can be performed with an autogeneic graft from various donor regions. Osteoconductive and osteoinductive bone substitutes originate from substances of diverse chemical and morphological types and can have a synthetic or a biological derivation. Alongside autogeneic bone transplants and allogenic and xenogeneic bone implants, alloplastic bone replacements of synthetic or semi-synthetic origin are being used for defect reconstruction. In an animal model in rabbits five bone substitutes and one autogeneic graft were surgically incorporated into identical bone defects (10times 10 mm in size) in six anatomically defined regions of the skull. With scintigraphic and histological methods, the metabolic dynamics of the bone is examined as it reacts to the transplantation of autogeneic bone or to implanted bone replacement material. The different autogeneic, xenogeneic and alloplastic bone replacement materials can be differentiated according to the functional quality of the new tissue and the dynamics of the bone conversion thus induced. In the comparison of mineralized, osteoconductive bone subsitutes (TCP, HA, calcium carbonate ceramics) with demineralized, osteoinductive implants (DBM new, DBM old) and autogeneic bone grafts, the bone inducing matrices show the largest quantity of new bone formation, making possible a volume-constant reconstruction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Diversity of cortical bone morphology in anuran amphibians

The cortical bones of mammals, birds, and reptiles are composed of a complex of woven bone and lamellar bone (fibrolamellar bone) organized into a variety of different patterns; however, it remains unclear whether amphibians possess similar structures. Importantly, to understand the evolutionary process of limb bones in tetrapods, it is necessary to compare the bone structure of amphibians (aquatic to terrestrial) with that of amniotes (mostly terrestrial). Therefore, this study compared the cortical bones in the long bones of several frog species before and after metamorphosis. Using micro-computed tomography (CT), we found that the cortical bones in the fibrolamellar bone of Xenopus tropicalis (Pipoidea superfamily) and Lithobates catesbeianus (Ranoidea superfamily) froglets are dense, whereas those of Ceratophrys cranwelli (Hyloidea superfamily) are porous. To clarify whether these features are common to their superfamily or sister group, four other frog species were examined. Histochemical analyses revealed porous cortical bones in C. ornata and Lepidobatrachus laevis (belonging to the same family, Ceratophryidae, as C. cranwelli). However, the cortical bones of Dryophytes japonicus (Hylidae, a sister group of Ceratophryidae in the Hyloidea superfamily), Microhyla okinavensis (Microhylidae, independent of the Hyloidea superfamily), and Pleurodeles waltl, a newt as an outgroup of anurans, are dense with no observed cavities. Our findings demonstrate that at least three members of the Ceratophryidae family have porous cortical bones similar to those of reptiles, birds, and mammals, suggesting that the process of fibrolamellar bone formation arose evolutionarily in amphibians and is conserved in the common ancestor of amniotes.