诱导实验性炎症： <ol><li>第一度晒伤引起的非皮肤晒黑了一个校准，紫外线B的源（Saalmann万用表SBB的LT 499，Saalmann有限责任公司，禧福，德国）的援助大腿。晒伤是一个微透析实验开始前三次运用必要的紫外线光量，导致完成泛红裸露的皮肤，或3倍最小红斑剂量（MED）诱导24小时。 MED是在研究开始之前，每个主题确定。准确地传递是有保证的能源与紫外线米Grobel紫外线博士电子公司，埃特林根，德国（12室）。 </li></ol>导管置入和样品的采集： <ol><li>准备一个临时区域，无菌手套，无菌持针器，1 1CC露儿提示注射器的23计（G）的针，与一个30G针头1CC注射器，1％利多卡因酒精棉签，2x2的无菌纱布垫，微透析导管连接在一个结束了一道4厘米的23G针（皮肤透析，德国埃尔兰根），和1.5毫升Microcent收集管4μl蛋白酶抑制剂每100微升样品干冰解决方案（科学E，K，圣克拉拉，加利福尼亚。）。蛋白酶抑制剂的解决方案是每个制造商的使用蛋白酶抑制剂的鸡尾酒片（罗氏诊断有限公司，曼海姆，德国）的指令。 </li><li>准备在乳酸林格氏液1％的人血白蛋白的解决方案，并绘制成1CC露儿提示注射器，确保无气泡留在注射器。 </li><li>与注射器装入1％的人类白蛋白，丰富林格到安装到一个高精密输液泵（泵22，哈佛器械，南Natic​​k郡，马的摇篮（微透析多注射器机架，哈佛大学器械，南纳提克，马）乳酸解决方案）。请一定的推动注射器，输液泵的酒吧是充分的接触与注射器的柱塞。设置后确认，注射器的直径已准确进入到泵泵的速度。常用的输注速率范围为2至4μl/min。 </li><li>您计划将收集您的样品从定义的区域。当一个人为制造的发炎区域，如晒伤，如上所述，计划在晒伤的边缘插入导管取样。 </li><li>清洁在小面积病变的对面边缘，或网站，你打算用酒精，收集的样本。这些清洁领域将导管的插入和退出点。注入刚够利多卡因在这些网站内cutaneously（发白的皮肤上注射证明），以创造一个非常小的的气泡（最高为2mm）。注射这种皮内利多卡因数量有限的微透析导管的入口和出口点不应该改变的生物测定的结果，但确实使插入导管为研究对象的痛苦大大减少。 </li><li>使用无菌技术，援助附加23G针插入微透析导管，在探索的皮肤面积长度。插入的深度是在表皮和皮下组织之间的接口。光学插入足够的深度可以验证。由于针和连接的导管是向前发展的针头应引起一点点向上折叠的皮肤，以及一些皮肤发白。无出血发生。如果确实发生出血，这表明，针是位于更深的比预期的插入深度调整。一旦针头已通过皮肤的退出点推，1％白蛋白丰富的乳酸林格氏溶液冲洗导管，沿导管的长度，直到你看到的水滴。这是通过仔细插入微透析导管末端的注射器（23G针）的针尾，慢慢注入解决方案。 </li><li>冲洗后的导管针轻轻拉饲料附加导管通过皮肤。温柔的处理是必要的，因为导管直径小，因此脆弱。拉导管，直到它完全通过皮肤线程，即，基地规模较大的塑料管嵌入导管末端接触皮肤切入点。如上所述，几乎没有在该过程结束时的出血确认最佳的导管置入。 </li><li>将23G针头的注射器，输液泵机架上的尖端导管的末端。需小心，以避免穿刺针通过导管壁，这将导致潜在的泄漏。 </li><li>切断近端导管针。 </li><li>使用粉色¼英寸磁带，高度接近导管出口部位的皮肤准备1.5毫升Microcent收集管。放入收集管导管的尖端，让microdialysate收集。开始灌注泵在预定ř和间歇性检查，交付和收集量相匹配。情况下，卷不匹配，从皮肤侵入部位的泄漏应被排除在外（有时可以解决拔导管的一部分，这是到皮肤进入网站更加紧密地嵌入塑料管材）。另外，导管可能需要更换，如果交付和收集的卷不匹配。 </li><li>一旦完成采样，样品放置，直​​到存储干冰在-80 ° C。 </li></ol>

<ol>
	<li>Angst, M. S., Clark, J. D., Carvalho, B., Tingle, M., Schmelz, M., Yeomans, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytokine+profile+in+human+skin+in+response+to+experimental+inflammation,+noxious+stimulation+and+administration+of+a+COX-inhibitor:+A+microdialysis+study.">Cytokine profile in human skin in response to experimental inflammation, noxious stimulation and administration of a COX-inhibitor: A microdialysis study.</a> Pain. 139, 15-27 (2008).</li></ol>

The authors have nothing to disclose.

微透析技术和多重免疫检测技术的结合使用，是一个宝贵的实时，人体内生物活性提供利益的组织的生化事件的洞察力。结合行为测试，如疼痛测试，该方法允许调解疼痛和炎症的生化物质之间复杂的相互作用研究。有前途的方法是1）确定组织特定的生物标志物介导的疼痛和炎症，2）提供到与周围组织的病变炎症和慢性疼痛的条件的病理机理的认识，以及3）探索镇痛/反hyperalgesic和抗炎行动新的候选药物和介入...

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		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
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<tr>
<td>Microdialysis catheter</td>
<td>Tool</td>
<td>Dermal Dialysis</td>
<td>NA</td>
<td>&nbsp;</td>
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<td>Pump 22</td>
<td>Tool</td>
<td>Harvard Apparatus</td>
<td>552219</td>
<td>&nbsp;</td>
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<td>Saalmann Multitester SBB LT 400</td>
<td>Tool</td>
<td>Saalmann GmbH</td>
<td>NA</td>
<td>&nbsp;</td>
<tr>
<td>RM-12 IP-65 Radiometer</td>
<td>Tool</td>
<td>Dr. Grobel UV Elektronik GmbH</td>
<td>82120000/81112100</td>
<td>&nbsp;</td>
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<td>Complete Proteinase Inhibitor</td>
<td>Reagent</td>
<td>Roche Bioscience</td>
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<td>&nbsp;</td>
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<td>Microcent tube</td>
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<td>E&K Scientific</td>
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<td>Lactated Ringer</td>
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<td>Hospira Inc</td>
<td>NA</td>
<td>&nbsp;</td>
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<td>Xylocaine-MPF</td>
<td>Other</td>
<td>Astra Zeneca</td>
<td>NA</td>
<td>&nbsp;</td>
<tr>
<td>Syringe 1mL</td>
<td>Tool</td>
<td>Becton Dickinson Co</td>
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human in-vivo bioassay for the tissue-specific measurement of nociceptive and inflammatory mediators

这在人体内生物活性，可用于研究人类的志愿者和患者身上。样品收集相关组织的网站，如通过无菌插入微透析导管（皮肤透析，德国埃尔兰根）皮肤。这个例子说明的是收集实验发炎的皮肤在人类志愿者的组织间液。可以结合其他实验测试样品的采集。例如，当地公布的生物化学和主观实验发炎的皮肤疼痛刺激的敏感性的同时评估提供了关键的生化行为的环节，以确定疼痛和炎症的生物标志物。机械洞察生活的人的机体检测允许特定组织底层的疼痛和/或炎症过程。该方法也适合于研究现有的或新的干预措施的有效性 - 目标的痛苦和/或炎症性疾病的治疗 - 如新的候选药物。本文将收集人类研究对象的实验发炎的患处皮肤组织间液微透析技术的使用提供了详细的说明。通常处理多重珠阵列，使体积小50微升样品化验100分析物免疫援助组织间液样本。

Watch this Scientific Journal Video about Human In-Vivo Bioassay for the Tissue-Specific Measurement of Nociceptive and Inflammatory Mediators at JoVE.com

Human In-Vivo Bioassay for the Tissue-Specific Measurement of Nociceptive and Inflammatory Mediators

一个方法是为调解疼痛和炎症的生化物质的测量（在这里，实验发炎的皮肤）的相关组织网站的间质液样品在体内收集。

组织特异性的伤害性和炎症介质的测量人体内生物活性测定

This in-vivo human bioassay can be used to study human volunteers and patients. Samples are collected from pertinent tissue sites such as the skin via ...

human-vivo-bioassay-for-tissue-specific-measurement-nociceptive

Research

JoVE Journal

Biology

10.2K 次观看.  Stanford University School of Medicine. 一个方法是为调解疼痛和炎症的生化物质的测量（在这里，实验发炎的皮肤）的相关组织网站的间质液样品在体内收集。

视频: Human In-Vivo Bioassay for the Tissue-Specific Measurement of Nociceptive and Inflammatory Mediators

In vivo Micro-circulation Measurement in Skeletal Muscle by Intra-vital Microscopy

BACKGROUND: Regulatory factors and detailed physiology of in vivo microcirculation have remained not fully clarified after many different modalities of imaging had invented. While many macroscopic parameters of blood flow reflect flow velocity, changes in blood flow velocity and red blood cell (RBC) flux does not hold linear relationship in the microscopic observations. There are reports of discrepancy between RBC velocity and RBC flux, RBC flux and plasma flow volume, and of spatial and temporal heterogeneity of flow regulation in the peripheral tissues in microscopic observations, a scientific basis for the requirement of more detailed studies in microcirculatory regulation using intravital microscopy. METHODS: We modified Jeff Lichtman's method of in vivo microscopic observation of mouse sternomastoid muscles. Mice are anesthetized,
ventilated, and injected with PKH26L-fluorescently labeled RBCs for microscopic observation.RESULT &amp; CONCLUSIONS: Fluorescently labeled RBCs are detected and distinguished well by a wide-field microscope. Muscle contraction evoked by electrical stimulation induced increase in RBC flux. Quantification of other parameters including RBC velocity and capillary density were feasible. Mice tolerated well the surgery, injection of stained RBCs, microscopic observation, and electrical stimulation. No muscle or blood vessel damage was observed, suggesting that our method is relatively less invasive and suited for long-term observations.

A new versatile method for observation of microcirculation is presented. It is considered suitable for long-term observation, and for combination with pharmacophysiological or molecular biological interventions.

在体内微循环在骨骼肌内重要的显微镜测量

BACKGROUND: Regulatory factors and detailed physiology of in vivo microcirculation have remained not fully clarified after many different modalities of ...

科研

生物学

Collecting and Measuring Nociceptive and Inflammatory Mediators in Surgical Wounds 

We describe a methodology by which we are able to collect and measure inflammatory and nociceptive biochemical mediators at the surgical wound site. Collecting site-specific biochemical markers allows us to evaluate the relationship between surgical wound and serum levels; determine any associations between mediator release, pain and analgesic consumption; and evaluate the effect of systemic and peripheral drug administration on surgical wound biochemistry.
This methodology has been applied to healthy women undergoing elective cesarean delivery with spinal anesthesia. Wound exudate and serum mediators, in conjunction with pain scores and analgesics consumption were measured at 1, 6, 24, and 48 hours post-cesarean delivery. Biochemical mediators that were detected included IL-1&beta;, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, TNF&alpha;, INF&gamma;, G-CSF, GM-CSF, MCP-1 and MIP-1&beta;, nerve growth factor (NGF), prostaglandin E2 (PG-E2) and substance P. We found no correlations between wound and serum cytokines concentrations or time-release profiles (J Pain. 2008 Jul 9(7):650-7). This article describes and demonstrates the feasibility of collecting and assaying nociceptive and inflammatory mediators in surgical wounds at specific time points. The lack of significant correlations between serum and wound levels shows the importance of determining site-specific release if surgical wounds and localized pathologies are to be studied.

Collecting and Measuring Nociceptive and Inflammatory Mediators in Surgical Wounds

A technique to collect and measure surgical wound biochemical mediators at specific time points.

在手术伤口的痛觉及炎症介质的收集和测量

We describe a methodology by which we are able to collect and measure inflammatory and nociceptive biochemical mediators at the surgical wound site. ...

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions

Vacuolar and cytosolic pH are highly regulated in yeast cells and occupy a central role in overall pH homeostasis. We describe protocols for ratiometric measurement of pH in vivo using pH-sensitive fluorophores localized to the vacuole or cytosol. Vacuolar pH is measured using BCECF, which localizes to the vacuole in yeast when introduced into cells in its acetoxymethyl ester form. Cytosolic pH is measured with a pH-sensitive GFP expressed under control of a yeast promoter, yeast pHluorin. Methods for measurement of fluorescence ratios in yeast cell suspensions in a fluorimeter are described. Through these protocols, single time point measurements of pH under different conditions or in different yeast mutants have been compared and changes in pH over time have been monitored. These methods have also been adapted to a fluorescence plate reader format for high-throughput experiments. Advantages of ratiometric pH measurements over other approaches currently in use, potential experimental problems and solutions, and prospects for future use of these techniques are also described.

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions

Vacuolar and cytosolic pH can be measured in live yeast (S. cerevisiae) cells using ratiometric fluorescent dyes localized to specific cellular compartments. We describe procedures for measuring vacuolar pH with BCECF-AM, which localizes to the vacuole in yeast, and cytosolic pH with a cytosolic ratiometric pH-sensitive GFP (yeast pHluorin).

液泡和胞质pH值的测量<em&gt;在体内</em在酵母细胞悬浮液

Vacuolar and  cytosolic pH are highly regulated in yeast cells and occupy a central role in  overall pH homeostasis. We describe  protocols for ...

In Vivo Modeling of the Morbid Human Genome using Danio rerio

Here, we present methods for the development of assays to query potentially clinically significant nonsynonymous changes using in vivo complementation in zebrafish. Zebrafish (Danio rerio) are a useful animal system due to their experimental tractability; embryos are transparent to enable facile viewing, undergo rapid development ex vivo, and can be genetically manipulated.1 These aspects have allowed for significant advances in the analysis of embryogenesis, molecular processes, and morphogenetic signaling. Taken together, the advantages of this vertebrate model make zebrafish highly amenable to modeling the developmental defects in pediatric disease, and in some cases, adult-onset disorders. Because the zebrafish genome is highly conserved with that of humans (~70% orthologous), it is possible to recapitulate human disease states in zebrafish. This is accomplished either through the injection of mutant human mRNA to induce dominant negative or gain of function alleles, or utilization of morpholino (MO) antisense oligonucleotides to suppress genes to mimic loss of function variants. Through complementation of MO-induced phenotypes with capped human mRNA, our approach enables the interpretation of the deleterious effect of mutations on human protein sequence based on the ability of mutant mRNA to rescue a measurable, physiologically relevant phenotype. Modeling of the human disease alleles occurs through microinjection of zebrafish embryos with MO and/or human mRNA at the 1-4 cell stage, and phenotyping up to seven days post fertilization (dpf). This general strategy can be extended to a wide range of disease phenotypes, as demonstrated in the following protocol. We present our established models for morphogenetic signaling, craniofacial, cardiac, vascular integrity, renal function, and skeletal muscle disorder phenotypes, as well as others.

In Vivo Modeling of the Morbid Human Genome using Danio rerio

Here, we present a systematic approach for developing physiologically relevant, sensitive and specific in vivo assays for interpreting variation in human pathology. Transient genetic manipulation via microinjection of WT and mutant human mRNA and morpholino (MO) antisense oligonucleotides harness the tractability of the developing zebrafish embryo to rapidly assay pathogenic mutations, especially, but not exclusively, in the context of human developmental disorders.

在体内病态的人类基因组建模使用斑马鱼

Here,  we present methods for the development of assays to query potentially clinically  significant nonsynonymous changes using in  vivo complementation ...

A Simple Bioassay for the Evaluation of Vascular Endothelial Growth Factors

The analysis of receptor tyrosine kinases and their interacting ligands involved in vascular biology is often challenging due to the constitutive expression of families of related receptors, a broad range of related ligands and the difficulty of dealing with primary cultures of specialized endothelial cells. Here we describe a bioassay for the detection of ligands to the vascular endothelial growth factor receptor-2 (VEGFR-2), a key transducer of signals that promote angiogenesis and lymphangiogenesis. A cDNA encoding a fusion of the extracellular (ligand-binding) region of VEGFR-2 with the transmembrane and cytoplasmic regions of the erythropoietin receptor (EpoR) is expressed in the factor-dependent cell line Ba/F3. This cell line grows in the presence of interleukin-3 (IL-3) and withdrawal of this factor results in death of the cells within 24 hr. Expression of the VEGFR-2/EpoR receptor fusion provides an alternative mechanism to promote survival and potentially proliferation of stably transfected Ba/F3 cells in the presence of a ligand capable of binding and cross-linking the extracellular portion of the fusion protein (i.e., one that can cross-link the VEGFR-2 extracellular region). The assay can be performed in two ways: a semi-quantitative approach in which small volumes of ligand and cells permit a rapid result in 24 hr, and a quantitative approach involving surrogate markers of a viable cell number. The assay is relatively easy to perform, is highly responsive to known VEGFR-2 ligands and can accommodate extracellular inhibitors of VEGFR-2 signaling such as monoclonal antibodies to the receptor or ligands, and soluble ligand traps.

We describe a simple cell-based bioassay for detecting, quantifying and monitoring the activity of members of the vascular endothelial growth factor family of ligands. The assay uses chimeric receptors expressed in a factor-dependent cell line to provide a semi-quantitative or quantitative assessment of receptor binding and cross-linking by the ligand.

一个简单的生物测定血管内皮生长因子的评价

The analysis of receptor tyrosine kinases and their interacting ligands involved in vascular biology is often challenging due to the constitutive ...

Gap Junctional Intercellular Communication: A Functional Biomarker to Assess Adverse Effects of Toxicants and Toxins, and Health Benefits of Natural Products

This protocol describes a scalpel loading-fluorescent dye transfer (SL-DT) technique that measures intercellular communication through gap junction channels, which is a major intercellular process by which tissue homeostasis is maintained. Interruption of gap junctional intercellular communication (GJIC) by toxicants, toxins, drugs, etc. has been linked to numerous adverse health effects. Many genetic-based human diseases have been linked to mutations in gap junction genes. The SL-DT technique is a simple functional assay for the simultaneous assessment of GJIC in a large population of cells. The assay involves pre-loading cells with a fluorescent dye by briefly perturbing the cell membrane with a scalpel blade through a population of cells. The fluorescent dye is then allowed to traverse through gap junction channels to neighboring cells for a designated time. The assay is then terminated by the addition of formalin to the cells. The spread of the fluorescent dye through a population of cells is assessed with an epifluorescence microscope and the images are analyzed with any number of morphometric software packages that are available, including free software packages found on the public domain. This assay has also been adapted for in vivo studies using tissue slices from various organs from treated animals. Overall, the SL-DT assay can serve a broad range of in vitro pharmacological and toxicological needs, and can be potentially adapted for high throughput set-up systems with automated fluorescence microscopy imaging and analysis to elucidate more samples in a shorter time.

This protocol describes a scalpel loading-fluorescent dye transfer technique that measures intercellular communication through gap junction channels. Gap junctional intercellular communication is a major cellular process by which tissue homeostasis is maintained and disruption of this cell signaling has adverse health effects.

间隙连接通讯：天然产物的生物标志物的功能，以评估毒物和毒素的不利影响，以及健康的益处

This protocol describes a scalpel loading-fluorescent dye transfer (SL-DT) technique that measures intercellular communication through gap junction ...

Murine Aortic Crush Injury: An Efficient In Vivo Model of Smooth Muscle Cell Proliferation and Endothelial Function

Arterial reconstruction, whether angioplasty or bypass surgery, involves iatrogenic trauma causing endothelial disruption and vascular smooth muscle cell (VSMC) proliferation. Common murine models study small vessels such as the carotid and femoral arteries. Herein we describe an in vivo system in which both VSMC proliferation and endothelial barrier function can be simultaneously assessed in a large vessel. We studied the infrarenal aortic response to injury in C57BL/6 mice. The aorta was injured from the left renal vein to the aortic bifurcation by 30 transmural crushes of 5-seconds duration with a cotton-tipped applicator. Morphological changes were assessed with conventional histology. Aorta wall thickness was measured from the luminal surface to the adventitia. EdU integration and counter staining with DAPI and alpha-actin was used to demonstrate VSMC proliferation. Activation of ERK1/2, a known moderator of intimal hyperplasia formation, was determined by Western Blot analysis. The effect of inflammation was determined by immunohistochemistry for B-cells, T-cells, and macrophages. En face sections of endothelium were visualized with scanning electron microscopy (SEM). Endothelial barrier function was determined with Evans Blue staining. Transmural injury resulted in aortic wall thickening. This injury induced VSMC proliferation, most prominently at 3 days after injury, and early activation of ERK1/2 and decreased p27kip1 expression. Injury did not result in increased B-cells, T-cells, or macrophages infiltration in the vessel wall. Injury caused partial endothelial cell denudation and loss of cell-cell contact. Injury resulted in a significant loss of endothelial barrier function, which returned to baseline after seven days. The murine transmural blunt aortic injury model provides an efficient system to simultaneously study both VSMC proliferation and endothelial barrier function in a large vessel.

Murine Aortic Crush Injury: An Efficient In Vivo Model of Smooth Muscle Cell Proliferation and Endothelial Function

Restenosis following cardiovascular procedures (bypass surgery, angioplasty, or stenting) is a significant problem reducing the durability of these procedures. An ideal therapy would inhibit smooth muscle cell (VSMC) proliferation while promoting regeneration of the endothelium. We describe a model for simultaneous assessment of VSMC proliferation and endothelial function in vivo.

小鼠主动脉夹层损伤：高效<em&gt;体内</em&gt;平滑肌细胞增殖和内皮功能模型

Arterial reconstruction, whether angioplasty or bypass surgery, involves iatrogenic trauma causing endothelial disruption and vascular smooth muscle cell ...

Using Caenorhabditis elegans to Screen for Tissue-Specific Chaperone Interactions

Correct folding and assembly of proteins and protein complexes are essential for cellular function. Cells employ quality control pathways that correct, sequester or eliminate damaged proteins to maintain a healthy proteome, thus ensuring cellular proteostasis and preventing further protein damage. Because of redundant functions within the proteostasis network, screening for detectable phenotypes using knockdown or mutations in chaperone-encoding genes in the multicellular organism Caenorhabditis elegans results in the detection of minor or no phenotypes in most cases. We have developed a targeted screening strategy to identify chaperones required for a specific function and thus bridge the gap between phenotype and function. Specifically, we monitor novel chaperone interactions using RNAi synthetic interaction screens, knocking-down chaperone expression, one chaperone at a time, in animals carrying a mutation in a chaperone-encoding gene or over-expressing a chaperone of interest. By disrupting two chaperones that individually present no gross phenotype, we can identify chaperones that aggravate or expose a specific phenotype when both perturbed. We demonstrate that this approach can identify specific sets of chaperones that function together to modulate the folding of a protein or protein complexes associated with a given phenotype.

Using Caenorhabditis elegans to Screen for Tissue-Specific Chaperone Interactions

To study chaperone-chaperone and chaperone-substrate interactions, we perform synthetic interaction screens in Caenorhabditis elegans using RNA interference in combination with mild mutations or over-expression of chaperones and monitor tissue-specific protein dysfunction at the organismal level.

使用 卡诺哈布迪炎埃莱甘斯 筛选组织特异性查佩龙相互作用

Correct folding and assembly of proteins and protein complexes are essential for cellular function. Cells employ quality control pathways that correct, ...

In vivo Measurement of Knee Extensor Muscle Function in Mice

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the clinic and the research laboratory, maximal muscular strength is widely measured longitudinally in humans, with knee extensor musculature the most reported functional outcome. Pathology of the knee extensor muscle complex is well documented in aging, orthopedic injury, disease, and disuse; knee extensor strength is closely related to functional capacity and injury risk, underscoring the importance of reliable measurement of knee extensor strength. Repeatable, in vivo assessment of knee extensor strength in pre-clinical rodent studies offers valuable functional endpoints for studies exploring osteoarthritis or knee injury. We report an in vivo and non-invasive protocol to repeatedly measure isometric peak tetanic torque of the knee extensors in mice across time. We demonstrate consistency using this novel method to measure knee extensor strength with repeated assessment in multiple mice producing similar results.

Quantification of knee extensor maximal strength is imperative to understand functional adaptations to aging, disease, injury, and rehabilitation. We present a novel method to repeatedly measure in vivo knee extension isometric peak tetanic torque.

小鼠膝盖外展肌肉功能的体内测量

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the ...

Rapid In Vivo Fixation and Isolation of Translational Complexes from Eukaryotic Cells

Rapid responses involving fast redistribution of messenger(m)RNA and alterations of mRNA translation are pertinent to ongoing homeostatic adjustments of the cells. These adjustments are critical to eukaryotic cell survivability and &#39;damage control&#39; during fluctuating nutrient and salinity levels, temperature, and various chemical and radiation stresses. Due to the highly dynamic nature of the RNA-level responses, and the instability of many of the RNA:RNA and RNA:protein intermediates, obtaining a meaningful snapshot of the cytoplasmic RNA state is only possible with a limited number of methods. Transcriptome-wide, RNA-seq-based ribosome profiling-type experiments are among the most informative sources of data for the control of translation. However, absence of a uniform RNA and RNA:protein intermediate stabilization can lead to different biases, particularly in the fast-paced cellular response pathways. In this article, we provide a detailed protocol of rapid fixation applicable to eukaryotic cells of different permeability, to aid in RNA and RNA:protein intermediate stabilization. We further provide examples of isolation of the stabilized RNA:protein complexes based on their co-sedimentation with ribosomal and poly(ribo)somal fractions. The separated stabilized material can be subsequently used as part of ribosome profiling-type experiments, such as in Translation Complex Profile sequencing (TCP-seq) approach and its derivatives. Versatility of the TCP-seq-style methods has now been demonstrated by the applications in a variety of organisms and cell types. The stabilized complexes can also be additionally affinity-purified and imaged using electron microscopy, separated into different poly(ribo)somal fractions and subjected to RNA sequencing, owing to the ease of the crosslink reversal. Therefore, methods based on snap-chilling and formaldehyde fixation, followed by the sedimentation-based or other type of RNA:protein complex enrichment, can be of particular interest in investigating finer details of rapid RNA:protein complex dynamics in live cells.

Rapid In Vivo Fixation and Isolation of Translational Complexes from Eukaryotic Cells

We present a technique to rapidly stabilize translational (protein biosynthesis) complexes with formaldehyde crosslinking in live yeast and mammalian cells. The approach enables dissecting transient intermediates and dynamic RNA:protein interactions. The crosslinked complexes can be used in multiple downstream applications such as in deep sequencing-based profiling methods, microscopy, and mass-spectrometry.

从真核细胞 中快速体内 固定和分离转化复合物

Rapid responses involving fast redistribution of messenger(m)RNA and alterations of mRNA translation are pertinent to ongoing homeostatic adjustments of ...