作者感谢安妮长臂猿，博士恭马偕博士在莫纳什大学动物服务的工作人员和生理学动物房。作者感谢杰里米Weinstein和Mcube团队的视频及动画production.a

<ol><li>羊是禁食24小时，但允许水自由采食</li><li>羊称重。 </li><li> Anaestheisa是诱发静脉注射硫喷妥钠（20mg/kg）。 </li><li>可给予预防性静脉注射抗生素。 </li><li>使用一个中型7日至9铐气管插管进行气管插管。 </li><li>麻醉与异氟醚，有1-3％是maintainted，在2L每分钟流量在100％的氧气。 </li><li>意见和麻醉水平的连续监测。 </li><li>此操作所需的手术工具包括:齿钳，无齿镊，梅岑鲍姆剪刀，梅奥剪刀，持针，手术刀处理（长期和短期），Kerrison rongeurs，垂体rongeurs，气动手术钻，钻头和警卫，神经钩（钝和微钩），电梯（即沃森进益），绝缘单极性和双极电刀钳，椎体分心（即16毫米卡斯帕引脚），撑开针钻和钻套，2-0，3-0角度刮匙尺寸7和10法国吸盘和吸气管， Langenback拉钩和自护颈椎拉钩。 </li><li>颈部是剃光，用优碘洗衣粉溶液洗净。 </li><li>动物走上了手术台，然后放置在仰卧位，颈部轻轻地延长。 </li><li>皮肤是用针和X射线确认的C3 / 4级标记。 </li><li>颈部，然后prepped使用洗必泰酒精，酒精碘酒和70％的乙醇在水中。 </li><li>一个方孔的悬垂性，是用于手术部位的开销表和一个大型广场悬垂。 </li><li>手术显微镜或放大镜放大倍率和大灯，可用于外科手术。 </li><li>切口使用手术刀在先前确定的网站使用的X射线</li><li>下一步，通过投资层的夹层是用剪刀和一架飞机研制内侧颈动脉鞘和横向气管和食管。 </li><li>通过使用电疗的过程止血是保持</li><li>一旦位于脊柱中线应触诊，并应小心，以确保回缩内侧，颈内动脉和外侧，气管和食管。 </li><li>一个用刺刀针，然后插入光盘（这样可以防止意外的进步，这可能损害脊髓）。一个方形的悬垂性，是用于支付手术部位。前，术中X射线确认的C3 / 4椎间盘水平。 </li><li>卡斯帕分心引脚，然后分别插入C3和C4。 </li><li>该光盘是阴刻15手术刀刀片。 </li><li>分心是然后插入椎间隙轻轻除了分心。 </li><li>一个椎间盘切除，然后进行使用rongeurs和Kerrison rongeurs。一个钻及刮匙也可能的援助。 </li><li>终板，然后准备使用的钻及刮匙，直至出血骨可视化。 </li><li>后纵韧带可能会开在这一点上，根据实验设计。一个钝钩和1mm Kerrison最适用于此过程。 </li><li>伤口，然后用生理盐水灌溉，前椎间融合器或测试材料的插入。 </li><li>分心是放宽广告设备检查，以确保它是安全的地方。 </li><li>然后取出撑开引脚和骨蜡，可插入实现在骨孔止血。 </li><li>长肌大肠杆菌肌肉与薇乔封闭。然后进行分层封闭，最好是用subcuticular缝合线，以避免需要拆线。 </li><li> Xylocaine是手术部位周围的渗透</li><li> anaestheitc气体被关闭，当出现自主呼吸和吞咽的迹象是明显的，气管导管被删除。 </li><li>动物是在不断观察代谢笼然后让其恢复。 </li><li>这是很重要的定位下夹着，防止返流腿直立的动物。 </li><li>一旦动物站立（通常在1小时内）的食物和水可被重新引入。 </li><li>执行24小时密切监视，并持续1周。 </li><li>镇痛维持了3天以下操作芬太尼补丁。 </li></ol>

<ol>
	<li>Angevine, P. D., Arons, R. R., McCormick, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=National+and+regional+rates+and+variation+of+cervical+discectomy+with+and+without+anterior+fusion,+1990-1999.">National and regional rates and variation of cervical discectomy with and without anterior fusion, 1990-1999.</a> Spine. 28, 931-940 (2003).</li><li>Cloward, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anterior+approach+for+removal+of+ruptured+cervical+disks.">The anterior approach for removal of ruptured cervical disks.</a> J Neurosurg. 15, 602-617 (1958).</li><li>Jacobs, W. C., Anderson, P. G., Limbeek, J., Willems, P. C., Pavlov, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+or+double-level+anterior+interbody+fusion+techniques+for+cervical+degenerative+disc+disease.">Single or double-level anterior interbody fusion techniques for cervical degenerative disc disease.</a> Cochrane Database Syst Rev. , CD004958-CD004958 (2004).</li><li>Kandziora, F., Pflugmacher, R., Scholz, M., Schnake, K., Lucke, M., Schr&#246;der, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+between+sheep+and+human+cervical+spines:+an+anatomic,+radiographic,+bone+mineral+density,+and+biomechanical+study.">Comparison between sheep and human cervical spines: an anatomic, radiographic, bone mineral density, and biomechanical study.</a> Spine. 26, 1028-1037 (2001).</li><li>Patil, P. G., Turner, D. A., 	Pietrobon, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=National+trends+in+surgical+procedures+for+degenerative+cervical+spine+disease:+1990-2000.">National trends in surgical procedures for degenerative cervical spine disease: 1990-2000.</a> Neurosurgery. 57, 753-758 (2005).</li><li>Smith, G. W., Robinson, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+treatment+of+certain+cervical-spine+disorders+by+anterior+removal+of+the+intervertebral+disc+and+interbody+fusion.">The treatment of certain cervical-spine disorders by anterior removal of the intervertebral disc and interbody fusion.</a> J Bone Joint Surg Am. 40-A, 607-624 (1958).</li></ol>

有一些变异来源的考虑，而规划和执行颈椎前路椎间盘切除术和融合。因此，动物模型的一致性，应是相同的年龄和品种。我们宁愿两岁，杂交莱斯特美利奴羊。如果正确执行，将有最小的并发症如出血，感染，或死亡率等。出血应控制整个过程和检查，然后再关闭haemosatsis。预防性antiobiotics感应到minimse感染的风险。从临床兽医的咨询和帮助是无价的，应及早寻求。程序是一般耐受性良好。 <p...

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		<th>Type</th>
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		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Marcain</td>
<td>&nbsp;</td>
<td>AstraZeneca</td>
<td>&nbsp;</td>
<td>0/5% Bupivicaine hydrochloride solution for injection 100mg in 20 mls</td>
</tr>
<tr>
<td>Thiopentone</td>
<td>&nbsp;</td>
<td>Illium</td>
<td>&nbsp;</td>
<td>Thiopentone sodium (sterile powder for injection) 5g</td>
</tr>
<tr>
<td>Issoranne</td>
<td>&nbsp;</td>
<td>Baxter</td>
<td>&nbsp;</td>
<td>Isoflurane BP 100%</td>
</tr>
<tr>
<td>Chlorehxidine</td>
<td>&nbsp;</td>
<td>Jurox</td>
<td>&nbsp;</td>
<td>40mg/ml Chlorhexidine glucoronate</td>
</tr>
<tr>
<td>PVD Iodine Solution</td>
<td>&nbsp;</td>
<td>Apex</td>
<td>&nbsp;</td>
<td>Povidine Iodine 100mg/ml</td>
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anterior cervical discectomy and fusion in the ovine model

颈椎前路椎间盘切除术和融合（ACDF）是最常见的的颈椎神经根和/或脊髓手术保守治疗失败的患者<sup&gt; 1,5</sup&gt;。由于操作最初是由Cloward<sup&gt; 2</sup&gt;和史密斯和罗宾逊<sup&gt; 6</sup在1958年，在技术，移植材料和植入各种精炼已<sup&gt; 3</sup&gt;。特别是，需要有一个安全的骨诱导剂，能入选患者受益。绵羊模型已被证明有解剖学，生物力学，骨密度和放射性质，类似于人类的对手，最相近的水平，C3 / 4<sup&gt; 4</sup&gt;。因此这是一个理想的模式，即可以进行临床前研究。特别感兴趣的研究人员在评估不同的设备和生物制剂，包括干细胞，为人类的脊柱外科手术中的潜在应用，这种方法可能是有用的的。

Watch this Scientific Journal Video about Anterior Cervical Discectomy and Fusion in the Ovine Model at JoVE.com

Anterior Cervical Discectomy and Fusion in the Ovine Model

本视频演示了颈椎前路椎间盘切除术在绵羊模型的融合技术。

颈椎前路椎间盘切除术和融合在绵羊模型

Anterior cervical discectomy and fusion (ACDF) is the most common surgical operation for cervical radiculopathy and/or myelopathy in patients who have ...

anterior-cervical-discectomy-and-fusion-in-the-ovine-model

Research

JoVE Journal

Biology

12.8K 次观看.  Monash University. 本视频演示了颈椎前路椎间盘切除术在绵羊模型的融合技术。

视频: Anterior Cervical Discectomy and Fusion in the Ovine Model

Method for Measurement of Viral Fusion Kinetics at the Single Particle Level

Membrane fusion is an essential step during entry of enveloped viruses into cells. Conventional fusion assays typically report on a large number of fusion events, making it difficult to quantitatively analyze the sequence of the molecular steps involved. We have developed an in vitro, two-color fluorescence assay to monitor kinetics of single virus particles fusing with a target bilayer on an essentially fluid support.
Influenza viral particles are incubated with a green lipophilic fluorophore to stain the membrane and a red hydrophilic fluorophore to stain the viral interior. We deposit a ganglioside-containing lipid bilayer on the dextran-functionilized glass surface of a flow cell, incubate the viral particles on the planar bilayer and image the fluorescence of a 100 x 100 &mu;m2 area, containing several hundreds of particles, on a CCD camera. By imaging both the red and green fluorescence, we can simultaneously monitor the behavior of the membrane dye (green) and the aqueous content (red) of the particles.
Upon lowering the pH to a value below the fusion pH, the particles will fuse with the membrane. Hemifusion, the merging of the outer leaflet of the viral membrane with the outer leaflet of the target membrane, will be visible as a sudden change in the green fluorescence of a particle. Upon the subsequent fusion of the two remaining distal leaflets a pore will be formed and the red-emitting fluorophore in the viral particle will be released under the target membrane. This event will give rise to a decrease of the red fluorescence of individual particles. Finally, the integrated fluorescence from a pH-sensitive fluorophore that is embedded in the target membrane reports on the exact time of the pH drop.
From the three fluorescence-time traces, all the important events (pH drop, lipid mixing upon hemifusion, content mixing upon pore formation) can now be extracted in a straightforward manner and for every particle individually. By collecting the elapsed times for the various transitions for many individual particles in histograms, we can determine the lifetimes of the corresponding intermediates. Even hidden intermediates that do not have a direct fluorescent observable can be visualized directly from these histograms.

We present an in vitro, two-color fluorescence assay to visualize the fusion of single virus particles with a fluid target bilayer. By labeling viral particles with fluorophores that differentially stain the viral membrane and its interior, we are able to monitor the kinetics of hemifusion and pore formation.

病毒融合动力学测量方法在单粒子能级

Membrane fusion is an essential step during entry of enveloped viruses into cells. Conventional fusion assays typically report on a large number of fusion ...

科研

生物学

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay

The interactions of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins on vesicles (v-SNAREs) and on target membranes (t-SNAREs) catalyze intracellular vesicle fusion1-4. Reconstitution assays are essential for dissecting the mechanism and regulation of SNARE-mediated membrane fusion5. In a cell fusion assay6,7, SNARE proteins are expressed ectopically at the cell surface. These "flipped" SNARE proteins drive cell-cell fusion, demonstrating that SNAREs are sufficient to fuse cellular membranes. Because the cell fusion assay is based on microscopic analysis, it is less efficient when used to analyze multiple v- and t-SNARE interactions quantitatively.
Here we describe a new assay8 that quantifies SNARE-mediated cell fusion events by activated expression of &beta;-galactosidase. Two components of the Tet-Off gene expression system9 are used as a readout system: the tetracycline-controlled transactivator (tTA) and a reporter plasmid that encodes the LacZ gene under control of the tetracycline-response element (TRE-LacZ). We transfect tTA into COS-7 cells that express flipped v-SNARE proteins at the cell surface (v-cells) and transfect TRE-LacZ into COS-7 cells that express flipped t-SNARE proteins at the cell surface (t-cells). SNARE-dependent fusion of the v- and t-cells results in the binding of tTA to TRE, the transcriptional activation of LacZ and expression of &beta;-galactosidase. The activity of &beta;-galactosidase is quantified using a colorimetric method by absorbance at 420 nm.
The vesicle-associated membrane proteins (VAMPs) are v-SNAREs that reside in various post-Golgi vesicular compartments10-15. By expressing VAMPs 1, 3, 4, 5, 7 and 8 at the same level, we compare their membrane fusion activities using the enzymatic cell fusion assay. Based on spectrometric measurement, this assay offers a quantitative approach for analyzing SNARE-mediated membrane fusion and for high-throughput studies.

We have developed a cell fusion assay that quantifies SNARE-mediated membrane fusion events by activated expression of &beta;-galactosidase.

SNARE蛋白介导的膜融合酶的细胞融合含量的分析

The interactions of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)  proteins on vesicles (v-SNAREs) and on target membranes ...

Evaluation of Muscle Function of the Extensor Digitorum Longus Muscle Ex vivo and Tibialis Anterior Muscle In situ in Mice

Body movements are mainly provided by mechanical function of skeletal muscle. Skeletal muscle is composed of numerous bundles of myofibers that are sheathed by intramuscular connective tissues. Each myofiber contains many myofibrils that run longitudinally along the length of the myofiber. Myofibrils are the contractile apparatus of muscle and they are composed of repeated contractile units known as sarcomeres. A sarcomere unit contains actin and myosin filaments that are spaced by the Z discs and titin protein. Mechanical function of skeletal muscle is defined by the contractile and passive properties of muscle. The contractile properties are used to characterize the amount of force generated during muscle contraction, time of force generation and time of muscle relaxation. Any factor that affects muscle contraction (such as interaction between actin and myosin filaments, homeostasis of calcium, ATP/ADP ratio, etc.) influences the contractile properties. The passive properties refer to the elastic and viscous properties (stiffness and viscosity) of the muscle in the absence of contraction. These properties are determined by the extracellular and the intracellular structural components (such as titin) and connective tissues (mainly collagen) 1-2. The contractile and passive properties are two inseparable aspects of muscle function. For example, elbow flexion is accomplished by contraction of muscles in the anterior compartment of the upper arm and passive stretch of muscles in the posterior compartment of the upper arm. To truly understand muscle function, both contractile and passive properties should be studied.
The contractile and/or passive mechanical properties of muscle are often compromised in muscle diseases. A good example is Duchenne muscular dystrophy (DMD), a severe muscle wasting disease caused by dystrophin deficiency 3. Dystrophin is a cytoskeletal protein that stabilizes the muscle cell membrane (sarcolemma) during muscle contraction 4. In the absence of dystrophin, the sarcolemma is damaged by the shearing force generated during force transmission. This membrane tearing initiates a chain reaction which leads to muscle cell death and loss of contractile machinery. As a consequence, muscle force is reduced and dead myofibers are replaced by fibrotic tissues 5. This later change increases muscle stiffness 6. Accurate measurement of these changes provides important guide to evaluate disease progression and to determine therapeutic efficacy of novel gene/cell/pharmacological interventions. Here, we present two methods to evaluate both contractile and passive mechanical properties of the extensor digitorum longus (EDL) muscle and the contractile properties of the tibialis anterior (TA) muscle.

Evaluation of Muscle Function of the Extensor Digitorum Longus Muscle Ex vivo and Tibialis Anterior Muscle In situ in Mice

Changes in limb muscle contractile and passive mechanical properties are important biomarkers for muscle diseases. This manuscript describes physiological assays to measure these properties in the murine extensor digitorum longus and tibialis anterior muscles.

伸趾长肌的肌肉功能评价<em&gt;体外</em和胫骨前肌<em在原位</em在小鼠

Body  movements are mainly provided by mechanical function of skeletal muscle. Skeletal  muscle is composed of numerous bundles of myofibers that are ...

Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism

The folding and assembly of proteins is essential for protein function, the long-term health of the cell, and longevity of the organism. Historically, the function and regulation of protein folding was studied in vitro, in isolated tissue culture cells and in unicellular organisms. Recent studies have uncovered links between protein homeostasis (proteostasis), metabolism, development, aging, and temperature-sensing. These findings have led to the development of new tools for monitoring protein folding in the model metazoan organism Caenorhabditis elegans. In our laboratory, we combine behavioral assays, imaging and biochemical approaches using temperature-sensitive or naturally occurring metastable proteins as sensors of the folding environment to monitor protein misfolding. Behavioral assays that are associated with the misfolding of a specific protein provide a simple and powerful readout for protein folding, allowing for the fast screening of genes and conditions that modulate folding. Likewise, such misfolding can be associated with protein mislocalization in the cell. Monitoring protein localization can, therefore, highlight changes in cellular folding capacity occurring in different tissues, at various stages of development and in the face of changing conditions. Finally, using biochemical tools ex vivo, we can directly monitor protein stability and conformation. Thus, by combining behavioral assays, imaging and biochemical techniques, we are able to monitor protein misfolding at the resolution of the organism, the cell, and the protein, respectively.

Using Caenorhabditis elegans as a Model System to Study Protein Homeostasis in a Multicellular Organism

To study the relationship between protein homeostasis, stress and aging, we monitored changes in protein folding by following protein dysfunction, protein localization in the cell and protein stability at the organismal, cellular and protein levels, using the genetically tractable metazoan Caenorhabditis elegans as a model system.

The folding and assembly of proteins is essential for protein function, the long-term health of the cell, and longevity of the organism. Historically, the ...

The Assembly and Application of 'Shear Rings': A Novel Endothelial Model for Orbital, Unidirectional and Periodic Fluid Flow and Shear Stress

Deviations from normal levels and patterns of vascular fluid shear play important roles in vascular physiology and pathophysiology by inducing adaptive as well as pathological changes in endothelial phenotype and gene expression. In particular, maladaptive effects of periodic, unidirectional flow induced shear stress can trigger a variety of effects on several vascular cell types, particularly endothelial cells. While by now endothelial cells from diverse anatomic origins have been cultured, in-depth analyses of their responses to fluid shear have been hampered by the relative complexity of shear models (e.g., parallel plate flow chamber, cone and plate flow model). While these all represent excellent approaches, such models are technically complicated and suffer from drawbacks including relatively lengthy and complex setup time, low surface areas, requirements for pumps and pressurization often requiring sealants and gaskets, creating challenges to both maintenance of sterility and an inability to run multiple experiments. However, if higher throughput models of flow and shear were available, greater progress on vascular endothelial shear responses, particularly periodic shear research at the molecular level, might be more rapidly advanced. Here, we describe the construction and use of shear rings: a novel, simple-to-assemble, and inexpensive tissue culture model with a relatively large surface area that easily allows for a high number of experimental replicates in unidirectional, periodic shear stress studies on endothelial cells.

The Assembly and Application of &#039;Shear Rings&#039;: A Novel Endothelial Model for Orbital, Unidirectional and Periodic Fluid Flow and Shear Stress

Different levels and patterns of fluid shear are known to modulate endothelial gene expression, phenotype and susceptibility to disease. We discuss the assembly and use of 'shear rings': a model that produces unidirectional, periodic shear stress patterns. Shear rings are simple to assemble, economical and can produce high cell yields.

大会和"剪切环"中的应用:一种新型内皮模型轨道，单向和定期流体流动和剪应力

Deviations from normal levels and patterns of vascular fluid shear play important roles in vascular physiology and pathophysiology by inducing adaptive as ...

Expression of Fluorescent Fusion Proteins in Murine Bone Marrow-derived Dendritic Cells and Macrophages

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation of an adaptive immune response. Experimental work with these cells is rather challenging. Their abundance in organs and tissues is relatively low. As a result, they cannot be isolated in large numbers. They are also difficult to transfect with cDNA constructs. In the murine model, these problems can be partially overcome by in vitro differentiation from bone marrow progenitors in the presence of M-CSF for macrophages or GM-CSF for dendritic cells. In this way, it is possible to obtain large amounts of these cells from very few animals. Moreover, bone marrow progenitors can be transduced with retroviral vectors carrying cDNA constructs during early stages of cultivation prior to their differentiation into bone marrow derived dendritic cells and macrophages. Thus, retroviral transduction followed by differentiation in vitro can be used to express various cDNA constructs in these cells. The ability to express ectopic proteins substantially extends the range of experiments that can be performed on these cells, including live cell imaging of fluorescent proteins, tandem purifications for interactome analyses, structure-function analyses, monitoring of cellular functions with biosensors and many others. In this article, we describe a detailed protocol for retroviral transduction of murine bone marrow derived dendritic cells and macrophages with vectors coding for fluorescently-tagged proteins. On the example of two adaptor proteins, OPAL1 and PSTPIP2, we demonstrate its practical application in flow cytometry and microscopy. We also discuss the advantages and limitations of this approach.

In this article, we provide a detailed protocol for the expression of fluorescent fusion proteins in murine bone marrow derived dendritic cells and macrophages. The method is based on the transduction of bone marrow progenitors with retroviral constructs followed by differentiation into macrophages and dendritic cells in vitro.

荧光融合蛋白在小鼠骨髓基质树突状细胞和巨噬细胞中的表达

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation ...

Real Time In Vivo Tracking of Thymocytes in the Anterior Chamber of the Eye by Laser Scanning Microscopy

The purpose of the method being presented is to show, for the first time, the transplant of newborn thymi into the anterior eye chamber of isogenic adult mice for in vivo longitudinal real-time monitoring of thymocytes&#180; dynamics within a vascularized thymus segment. Following the transplantation, laser scanning microscopy (LSM) through the cornea allows in vivo noninvasive repeated imaging at cellular resolution level. Importantly, the approach adds to previous intravital T-cell maturation imaging models the possibility for continuous progenitor cell recruitment and mature T-cell egress recordings in the same animal. Additional advantages of the system are the transparency of the grafted area, permitting macroscopic rapid monitoring of the implanted tissue, and the accessibility to the implant allowing for localized in addition to systemic treatments. The main limitation being the volume of the tissue that fits in the reduced space of the eye chamber which demands for lobe trimming. Organ integrity is maximized by dissecting thymus lobes in patterns previously shown to be functional for mature T-cell production. The technique is potentially suited to interrogate a milieu of medically relevant questions related to thymus function that include autoimmunity, immunodeficiency and central tolerance; processes which remain mechanistically poorly defined. The fine dissection of mechanisms guiding thymocyte migration, differentiation and selection should lead to novel therapeutic strategies targeting developing T cells.

Real Time In Vivo Tracking of Thymocytes in the Anterior Chamber of the Eye by Laser Scanning Microscopy

The goal of the protocol is to show longitudinal intravital real-time tracking of thymocytes by laser scanning microscopy in thymic implants in the anterior chamber of the mouse eye. The transparency of the cornea and vascularization of the graft allows for continuously recording progenitor cell recruitment and mature T-cell egress.

激光扫描显微术实时跟踪眼球前室胸腺细胞

The purpose of the method being presented is to show, for the first time, the transplant of newborn thymi into the anterior eye chamber of isogenic adult ...

Effect of Fluorescent Proteins on Fusion Partners Using Polyglutamine Toxicity Assays in Yeast

For the investigation of protein localization and trafficking using live cell imaging, researchers often rely on fusing their protein of interest to a fluorescent reporter. The constantly evolving list of genetically encoded fluorescent proteins (FPs) presents users with several alternatives when it comes to fluorescent fusion design. Each FP has specific optical and biophysical properties that can affect the biochemical, cellular, and functional properties of the resulting fluorescent fusions. For instance, several FPs tend to form nonspecific oligomers that are susceptible to impede on the function of the fusion partner. Unfortunately, only a few methods exist to test the impact of FPs on the behavior of the fluorescent reporter. Here, we describe a simple method that enables the rapid assessment of the impact of FPs using polyglutamine (polyQ) toxicity assays in the budding yeast Saccharomyces cerevisiae. PolyQ-expanded huntingtin proteins are associated with the onset of Huntington&#39;s disease (HD), where the expanded huntingtin aggregates into toxic oligomers and inclusion bodies. The aggregation and toxicity of polyQ expansions in yeast are highly dependent on the sequences flanking the polyQ region, including the presence of fluorescent tags, thus providing an ideal experimental platform to study the impact of FPs on the behavior of their fusion partner.

This article describes protocols to assess the effect of fluorescent proteins on the aggregation and toxicity of misfolded polyglutamine expansion for the rapid evaluation of a newly uncharacterized fluorescent protein in the context of fluorescent reporters.

荧光蛋白对酵母中多谷氨酰胺毒性测定的融合伙伴的影响

For the investigation of protein localization and trafficking using live cell imaging, researchers often rely on fusing their protein of interest to a ...

Production of IgG Fusion Proteins Transiently Expressed in Nicotiana benthamiana

High demand for antibodies as therapeutic interventions for various infectious, metabolic, autoimmune, neoplastic, and other diseases creates a growing need in developing efficient methods for recombinant antibody production. As of 2019, there were more than 70 FDA-approved monoclonal antibodies, and there is exponential growth potential. Despite their promise, limiting factors for widespread use are manufacturing costs and complexity. Potentially, plants offer low-cost, safe, and easily scalable protein manufacturing&#160;strategies. Plants like Nicotiana benthamiana not only can correctly fold and assemble complex mammalian proteins but also can add critical post-translational modifications similar to those offered by mammalian cell cultures. In this work, by using native GFP and an acid-stable variant of green fluorescent protein (GFP) fused to human monoclonal antibodies, we were able to visualize the entire transient antibody expression and purification process from N. benthamiana plants. Depending on the experiment&#39;s purpose, native GFP fusion can ensure easier visualization during the expression phase in the plants, while acid-stable GFP fusion allows for visualization during downstream processing. This scalable and straightforward procedure can be performed by a single researcher to produce milligram quantities of highly pure antibody or antibody fusion proteins in a matter of days using only a few small plants. Such a technique can be extended to the visualization of any type of antibody purification process and potentially many other proteins, both in plant and other expression systems. Moreover, these techniques can benefit virtual instructions and be executed in a teaching laboratory by undergraduate students possessing minimal prior experience with molecular biology techniques, providing a foundation for project-based exploration with real-world applications.

Production of IgG Fusion Proteins Transiently Expressed in Nicotiana benthamiana

We describe here a simple method for expression, extraction, and purification of recombinant human IgG fused to GFP in Nicotiana benthamiana. This protocol can be extended to purification and visualization of numerous proteins that utilize column chromatography. Moreover, the protocol is adaptable to the in-person and virtual college teaching laboratory, providing project-based exploration.

在尼科蒂亚娜本 thamiana中瞬态表达IgG融合蛋白的生产

High demand for antibodies as therapeutic interventions for various infectious, metabolic, autoimmune, neoplastic, and other diseases creates a growing ...

Microsurgical Obstruction of Testes Fusion in Spodoptera litura

Instead of using genetic methods like RNA interference (RNAi) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated endonuclease Cas9, a physical barrier was microsurgically inserted between the testes of Spodoptera litura to study the impact of this microsurgery on its growth and reproduction. After inserting aluminum foil between the testes, insect molting during metamorphosis proceeded normally. Insect growth and development were not remarkably altered; however, the number of sperm bundles changed if testes fusion was stopped by the microsurgery. These findings imply that blocking testicular fusion can influence male reproduction capability. The method can be further applied to interrupt communication between organs to study the function of specific signaling pathways. Compared to conventional surgery, microsurgery only requires freezing anesthetization, which is preferable to carbon dioxide anesthetization. Microsurgery also minimizes the surgery site area and facilitates wound healing. However, the selection of materials with specific functions needs further investigation. Avoiding tissue injury is crucial when making incisions during the operation.

Microsurgical Obstruction of Testes Fusion in Spodoptera litura

Aluminum foil was microsurgically inserted between the testes of Spodoptera litura to obstruct the fusion of testis. The procedure includes freezing, fixing, disinfection, incision, placing the barrier, suturing, postoperative feeding, and inspection. This approach provides a method to interfere with tissue formation.

睾丸融合的显微外科梗阻

Instead of using genetic methods like RNA interference (RNAi) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated ...