Name: a strain gauge monitor (sgm) for continuous valve gape measurements in bivalve molluscs in response to laboratory induced diel-cycling hypoxia and ph
Uploaded: 2018-08-01T14:00:00.000+00:00
Duration: 7 min 59 s
Description: Watch this Scientific Journal Video about A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH at JoVE.co

牡蠣の写真を撮る、ImageJ でぼうぜんとしている幅を測定、メリンダ ・ Forseth に感謝します。サイクリング低酸素と循環 pH 条件日周と、水槽へのアクセス、デニス Breitburg に感謝しますエッジウォーター, メリーランド州, スミソニアン環境研究センターは、実験スペースを感謝いたします。低酸素症実験された no.、国立海洋大気圏局 - 沿岸海洋研究のスポンサー助成センターによって資金を供給NA10NOS4780138 し、スミソニアン Hunterdon 基金デニス Breitburg します。バルブは、実験 Elka t. ポーターにワシントン大学によって学部強化助成金によって資金が供給された低酸素吸入時の測定をぼうぜんと。

我々 は明らかに何かを持っていません。

典型的な研究焦点、連続拡張低酸素条件の期間と応答は、しばしば動物の生存として測定します。ただし、現時点では、日周サイクリング低酸素に対する動物の行動応答の私達の理解は、最小限63です。したがってより多くの研究は多く河口7,8で夏に定期的に発生する日周サイクリングの低酸素に対する反応で有機体の行動に焦点...

低酸素症、すなわち、溶存酸素濃度 [] 十分に低を行う生物に悪影響を生態学的プロセスが、しばしば機能的に定義されたとして [行う] < 2 mg/L の1、および無酸素症の (機能的 [DO] として定義されている 0.0 0.2 mg/L)世界の沿岸水域、河口および海洋深層2,3でより頻繁に、深刻なを発生しているし、しばしば富栄養化4、5の増加によって悪化させます。低酸素血症と低酸素の増加面積程度、大型動物が悪影響を受けるし、生息地の範囲や生息場所の質を失います。気候変動は、低酸素、無酸素6を悪化させると予測されます。
チェサピーク湾、アメリカなど多くの成層、栄養強化河口で季節持続的な低酸素症勝つことができるし、2年後に起こります。さらに、低酸素の日周サイクリングはチェサピーク湾そして他の場所などの河口に頻繁に、夜や早朝時間の夏7,8の後期に起こる。
ほとんどの研究は、[は] を低に生物の連続的な露出の効果と低酸素と無酸素9,10、11,12,13,14 への耐性に焦点を当てています。.また、研究は、拡張低 [は]4,15に応えて種分布、組成、および種組成の大規模な変化を見てきました。しばしば種低固まりで死ぬ [行う] に非常に敏感な16ルイジアナ州、テキサス州棚生態系4として、たとえば、若い、小さいサイズ、短命の相に残りの種をシフトします。
行動の変化は通常コミュニティ崩壊17を前し、拡張低 [は]4,16,17,18,19 への生物の行動応答が報告されて ,,2021,22,23,24,25。しかし、これらの研究は、低酸素症の日周サイクリング エクスポー ジャーと河口では可用性の変動の性質への生物の応答にフォーカスしていません。
浅い河口域で日周サイクリング低酸素を受けている意識の高まり研究モニター詳細を行う頻繁ゾンデ河口16,26日間にわたって。水は夜の終わりに時間や夏の早朝時間に低酸素に残ることができる夜が高酸素消費の中に酸素を生成する光合成が無い場合好気呼吸7,16。また、日周が潮の干満に影響を受けることがわかりました低潮が夜27の終わりと重なったとき観測された最も極端な極小の低か条件のサイクリングします。[か] 低酸素症のいくつかの時間後にのみ毎日のサイクルに常7,16,28に帰ってくる。
日周サイクリング酸素分圧および pH 我々 は研究室にさらされるカキのバルブの開閉監視c. virginicaの行動応答を判断する誘導日周 [は] のサイクリングと循環 pH。二枚貝の gape 応答は、不利な環境条件を検出するために使用されています。汚染物質29,30,31, 有毒藻類32,33,34, 熱汚染35,36の応答における二枚貝類の弁閉鎖,37食べ物の量を減らす38,39,40, 供給体制39,41, エマーション37,42, 日長43,44、pH45,46, と結合された pH と溶存酸素47を測定しました。口を大きく開ける技術にはなどが含まれている直接観察48,49,13, リード スイッチと磁石 (Dreissena モニター)50、または光ファイバーセンサーを用いた連続測定には51澄んだ水を必要とします。さらに、磁石と磁場強度のホール センサーは、ムール貝、ぼうぜんとしている角度52,53,54,55, 高周波電磁誘導システムの検討に使用されています。ことができます測定バルブに接着されて 2 つの電気コイル間距離を変化させるされていること56,57,58,59を使用します。高電圧源は電磁誘導システムに必要な電源シェル52の両側に配信されます。このシステムは「MOSSELMONITOR」(http://mosselmonitor.nl/) として市販も。
研究室による日周以上安価なひずみゲージ モニター (SGM) オイスター gape を連続測定するタイトな研究予算で構築した [は] のサイクリング、pH、低い可視性の条件の下で。我々 のシステムも多くの動物実験中に計測する、競合するシステムよりもはるかに簡単です。日周深刻なサイクリングにC. virginicaの行動対応を決定したい ([行う] = 0.6 mg/L) pH コントロールと低酸素症 (pH = 7.8) とサイクリングの pH (pH = 7.8 7.0) をそれぞれと gape に対する軽度 ([行う] = 1.7 mg/L) 低酸素。また、カキあるサイクル、日周上 [か] と低酸素イベント後常が返されるときの対処方法の変化に迅速に対応することができるかどうかと考えました。おそらくカキは、彼らが住んでいる最適多く河口16,27は、「急速に変動の環境に適応されます。複雑なバルブ、ぼうぜんとしているモニターが利用可能な SGM は低視程条件でも水のバルブ gape の連続測定を可能にする安価な方法を提供しています。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57404/57404fig1.jpg"> 図 1。バルブ gape 用ホイートストン ブリッジします。<a href="/files/ftp_upload/57404/57404fig1large.jpg" target="_blank">この図の拡大版を表示するのにはここをクリックしてください</a>。
二枚貝 gape の監視用ひずみゲージ センサーは、バックアップ ポリイミド蛇行パターンで抵抗膜です。歪み量が少ないセンサーの抵抗を調節します。二枚貝は、それはセンサーの抵抗の変化をもたらす口をあけるときにひずみゲージを折り曲げ。センサーの抵抗の変化を測定する図 1に示すように、二枚貝のチャネルごとにヌル、バランスの取れた、ホイートス トーン ブリッジを採用しました。ホイートス トーン ブリッジはかなりハイゲイン データロガーに雇用されることを許可するポテンショメータによって null します。ホイートストン ブリッジは、標準的な既知抵抗と電圧計に比を用いた未知抵抗の正確な測定のための標準的な方法です。この非常に古い技術の歴史は、Ekelof (2001 年)60で論議されます。ひずみゲージ モニター (SGM) ユニットに 12 チャンネル、それぞれ独自のホイートストン ブリッジとヌルのポテンショメータを統合されています。

<table><tbody><tr><td>Campbell CR 10x data logger</td><td>Campbell Scientific, Logan, Utah</td><td></td><td>Or other data logger. At Campbell the CR 10X has been replaced with the CR 1000</td></tr><tr><td>Campbell CR 10x multiplexer</td><td>Campbell Scientific, Logan, Utah</td><td></td><td>Data logger needs to have space for 12 channels</td></tr><tr><td>Dsub connector male crimp pins</td><td>TE Connectivity</td><td>205089-1</td><td>pins for gape sensor leads</td></tr><tr><td>PCA tape</td><td>Micro Measurements Corp, NC</td><td></td><td>To seal the strain gauge</td></tr><tr><td>Duro Quick Gel</td><td>Ace Hardware</td><td></td><td>Superglue</td></tr><tr><td>SG13/1000-LY43 or LY41</td><td>Omega Engineering Inc., Stanford, CT</td><td></td><td>Strain gauges</td></tr><tr><td>32 AWG (7/40) teflon Alpha wires</td><td>AlphaWire, Elizabeth, NJ</td><td>2840/7</td><td>Sensor cables, different colors are available</td></tr><tr><td>1/16&quot; heat shrink tubing</td><td>Qualtek</td><td>B01A3QKKO6</td><td>To seal the leads of the sensor cable</td></tr><tr><td>Weller WES51 Analog Soldering Station</td><td>Amazon</td><td></td><td>Lots of soldering, need a good soldering iron. https://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU/ref=sr_1_23?s=hi&amp;amp;ie=UTF8&amp;amp;qid=1505654295&lt;br/&gt; &amp;amp;sr=1-23&amp;amp;keywords=soldering+iron</td></tr><tr><td>Rosin Soldering Flux Paste</td><td>Amazon</td><td></td><td>Needed for soldering</td></tr><tr><td>60-40 Tin Lead Rosin Core Solder Wire</td><td>Amazon</td><td></td><td>Needed for soldering</td></tr><tr><td>Aquarium sealant</td><td>Home Depot</td><td></td><td>Attach sensors to bivalve</td></tr><tr><td>PC Laptop</td><td></td><td></td><td>Any old PC to run Campbell gape program</td></tr><tr><td>heat gun</td><td>Amazon</td><td></td><td>shrink shrink tubing</td></tr><tr><td>Drill</td><td>Hardware store, Amazon</td><td></td><td>for twisting wires to make sensor cables</td></tr><tr><td>AC to DC power module</td><td>Acopian</td><td>DB15-30</td><td>Wheatstone bridge power supply</td></tr><tr><td>Poteniometer</td><td>Clarostat</td><td>733A</td><td>Wheatsone bridge nulling</td></tr><tr><td>isolating BNC connector</td><td>Sterren Electronics</td><td>&quot;200-148</td><td>Wheatstone bridge output for multimeter</td></tr><tr><td>Fused AC receptical panel module</td><td>Adam technologies</td><td>IEC-GS-1-200</td><td>Wheatstone bridge power supply connector</td></tr><tr><td>976 ohm 1% resistor</td><td>Vishay Dale</td><td>CMF50976R00FHEB</td><td>Wheatstone bridge resistor</td></tr><tr><td>1 kohm 1% resistor</td><td>Vishay Dale</td><td>CMF501K0000FHEB</td><td>Wheatstone bridge resistor</td></tr><tr><td>Potentiometer scale dial</td><td>Kilo International</td><td>462</td><td>10 turn dial for nulling potentiometer</td></tr><tr><td>DB25 male panel connector</td><td>TE connectivity</td><td>1757819-8</td><td>Data logger connector on Wheatstone bridge</td></tr><tr><td>DB25 female panel connector</td><td>TE connectivity</td><td>1757819-8</td><td>Sensor connector to Wheatstone bridge</td></tr><tr><td>perforated circuit board</td><td>Vector electronics</td><td>64P44WE</td><td>circuit board for mounting of bridge components</td></tr><tr><td>enclosure</td><td>Hammond Manufacturing</td><td>1444-29</td><td>Enclosure for sensor readout electronics</td></tr></tbody></table>

a strain gauge monitor (sgm) for continuous valve gape measurements in bivalve molluscs in response to laboratory induced diel-cycling hypoxia and ph

安価な実験室ベースのひずみゲージ弁 gape モニター (SGM) は、日周サイクリング低酸素に対する反応で二枚貝のバルブ口を大きく開ける動作を監視するため開発されました。ホイートストン ブリッジは、牡蠣 (マガキ virginica) のシェルに接続されているひずみゲージに接続されました。記録された信号許可を継続的に記録する二枚貝の開閉実験による日周サイクリングの低酸素と pH の変化を日周サイクリング 2 日間の期間。ここで、我々 は安価なひずみゲージ モニターを開発するためのプロトコルを記述する例の実験に記述して、東が日周サイクリング低酸素に対する反応で (C. virginica) を牡蠣のバルブ口を大きく開ける動作を測定するために使用私たちどのようにとpH の周期的変化。バルブ、ぼうぜんとしている循環的な重篤な低酸素 (0.6 mg/L) を受けるにカキに測定した溶存酸素条件と pH、循環的な軽度低酸素 (1.7 mg/L) 条件と平地 (7.3 mg/L) 条件の周期的な変化なし。示すカキには、繰り返される日周サイクルが発生した、彼ら急速に重度の低酸素に対する反応で自分の殻を閉じて軽度低酸素のタイムラグを閉じます。常が回復すると、彼らは急速に再度開きます。カキは、重度の低酸素症をサイクリング日周の上に重ね循環 pH 条件に応答しませんでした。低酸素条件下でカキの 3 分の 1 以上を同時に閉じる。カキ対応日周サイクリング低酸素症、酸素溶解する二枚貝の挙動を評価するとき考慮しなければならないことを示します。バルブ SGM は、溶存酸素や汚染物質の変化に二枚貝の応答を評価するために使用できます。技術より良いシールをシール海の水からバルブ gape ひずみゲージはセンサーの寿命を増加するそれ以上の改善を必要があります。

カキの中断のない平地河口水 (毎日のサイクルの低いプラトー段階低酸素) にさらされる時間のほとんどが開いていたし、簡潔にだけ頻繁に閉鎖 (図 5)。いつ彼らはカキからオイスターに様々 な閉じる。このパターンは、Loosanoff と Nomejko 194644とヒギンズ 198039も見つかってください。また、カキは、闇と光の位?...

Watch this Scientific Journal Video about A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH at JoVE.co

A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

ひずみゲージ モニター (SGM) 研究室による日周サイクリング酸素分圧および pH 応答の二枚貝軟体動物の連続弁 Gape 測定

二枚貝の懸濁液の送り装置の溶存酸素などの環境変数への行動応答を理解することはいくつかの生態系のプロセスを説明できます。安価な実験室ベースのひずみゲージ モニター (SGM) カキ、マガキ virginicaバルブ、ぼうぜんとしている応答を測定する日周サイクリング低酸素と循環 pH を開発しました。

An inexpensive, laboratory-based, strain gauge valve gape monitor (SGM) was developed to monitor the valve gape behavior of bivalve molluscs in response ...

a-strain-gauge-monitor-sgm-for-continuous-valve-gape-measurements

Universidad de Cartagena UDEC

Research

JoVE Journal

Environment

A Strain Gauge Monitor (SGM) for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

8.9K ビュー.  University of Baltimore. 二枚貝の懸濁液の送り装置の溶存酸素などの環境変数への行動応答を理解することはいくつかの生態系のプロセスを説明できます。安価な実験室ベースのひずみゲージ モニター (SGM) カキ、マガキ virginicaバルブ、ぼうぜんとしている応答を測定する日周サイクリング低酸素と循環 pH を開発しました。

ビデオ: A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

A Simple Approach to Manipulate Dissolved Oxygen for Animal Behavior Observations

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal behavior questions. The protocol described here provides a simple, reproducible, and controlled method to manipulate DO to study behavioral response in aquatic organisms resulting from hypoxic and anoxic conditions. While performing degasification of water with nitrogen is commonly used in laboratory settings, no explicit method for ecological (aquatic) application exists in the literature, and this protocol is the first to describe a protocol to degasify water to observe organismal response. This technique and protocol were developed for direct application for aquatic macroinvertebrates; however, small fish, amphibians, and other aquatic vertebrates could be easily substituted. It allows for easy manipulation of DO levels ranging from 2 mg/L to 11 mg/L with stability for up to a 5 min animal-observation period. Beyond a 5 min observation period water temperatures began to rise, and at 10 min DO levels became too unstable to maintain. The protocol is scalable to the study organism, reproducible, and reliable, allowing for rapid implementation into introductory teaching labs and high-level research applications. The expected results of this technique should relate dissolved oxygen changes to behavioral responses of organisms.

This article describes a simple and reproducible protocol to manipulate dissolved oxygen conditions in a laboratory setting for animal behavior studies. This protocol may be used in both teaching and research laboratory settings to evaluate organismal response of macroinvertebrates, fishes, or amphibians to changes in dissolved oxygen concentration.

動物の行動観察のための溶存酸素を操作するための単純なアプローチ

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal ...

環境学

Protocol for Relative Hydrodynamic Assessment of Tri-leaflet Polymer Valves

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of tri-leaflet polymer valve prostheses. However, identification of a protocol for initial assessment of polymer valve hydrodynamic functionality is paramount during the early stages of the design process. Traditional in vitro pulse duplicator systems are not configured to accommodate flexible tri-leaflet materials; in addition, assessment of polymer valve functionality needs to be made in a relative context to native and prosthetic heart valves under identical test conditions so that variability in measurements from different instruments can be avoided. Accordingly, we conducted hydrodynamic assessment of i) native (n = 4, mean diameter, D = 20 mm), ii) bi-leaflet mechanical (n= 2, D = 23 mm) and iii) polymer valves (n = 5, D = 22 mm) via the use of a commercially available pulse duplicator system (ViVitro Labs Inc, Victoria, BC) that was modified to accommodate tri-leaflet valve geometries. Tri-leaflet silicone valves developed at the University of Florida comprised the polymer valve group. A mixture in the ratio of 35:65 glycerin to water was used to mimic blood physical properties. Instantaneous flow rate was measured at the interface of the left ventricle and aortic units while pressure was recorded at the ventricular and aortic positions. Bi-leaflet and native valve data from the literature was used to validate flow and pressure readings. The following hydrodynamic metrics were reported: forward flow pressure drop, aortic root mean square forward flow rate, aortic closing, leakage&#160;and regurgitant volume, transaortic closing, leakage, and total energy losses. Representative results indicated that hydrodynamic metrics from the three valve groups could be successfully obtained by incorporating a custom-built assembly into a commercially available pulse duplicator system and subsequently, objectively compared to provide insights on functional aspects of polymer valve design.

There has been renewed interest in developing polymer valves. Here, the objectives are to demonstrate the feasibility of modifying a commercial pulse duplicator to accommodate tri-leaflet geometries and to define a protocol to present polymer valve hydrodynamic data in comparison to native and prosthetic valve data collected under near-identical conditions.

トライリーフレットポリマーバルブの相対的な流体力学的評価のためのプロトコル

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of ...

生物工学

Quantitative and Temporal Control of Oxygen Microenvironment at the Single Islet Level

Simultaneous oxygenation and monitoring of glucose stimulus-secretion coupling factors in a single technique is critical for modeling pathophysiological states of islet hypoxia, especially in transplant environments. Standard hypoxic chamber techniques cannot modulate both stimulations at the same time nor provide real-time monitoring of glucose stimulus-secretion coupling factors. To address these difficulties, we applied a multilayered microfluidic technique to integrate both aqueous and gas phase modulations via a diffusion membrane. This creates a stimulation sandwich around the microscaled islets within the transparent polydimethylsiloxane (PDMS) device, enabling monitoring of the aforementioned coupling factors via fluorescence microscopy. Additionally, the gas input is controlled by a pair of microdispensers, providing quantitative, sub-minute modulations of oxygen between 0-21%. This intermittent hypoxia is applied to investigate a new phenomenon of islet preconditioning. Moreover, armed with multimodal microscopy, we were able to look at detailed calcium and KATP channel dynamics during these hypoxic events. We envision microfluidic hypoxia, especially this simultaneous dual phase technique, as a valuable tool in studying islets as well as many ex vivo tissues.

Microfluidic oxygen control confers more than just convenience and speed over hypoxic chambers for biological experiments. Especially when implemented via diffusion through a membrane, microfluidic oxygen can provide simultaneous liquid and gas phase modulations at the microscale-level. This technique enables dynamic multi-parametric experiments critical for studying islet pathophysiology.

Simultaneous oxygenation and monitoring of glucose stimulus-secretion coupling factors in a single technique is critical for modeling pathophysiological ...

Design and Use of an Apparatus for Quantifying Bivalve Suspension Feeding at Sea

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves (i.e., mussels, oysters, and clams) presents new challenges. Quantitative data on the feeding behavior of suspension-feeding mollusks is necessary to determine important ecosystem interactions of offshore shellfish farms, including their carrying capacity, the competition with the zooplankton community, the availability of trophic resources at different depths, and the deposition to the benthos. The biodeposition method is used to quantify feeding variables in suspension-feeding bivalves in a natural setting and represents a more realistic proxy than laboratory experiments. This method, however, relies upon a stable platform to satisfy the requirements that water flow rates supplied to the shellfish remain constant and the bivalves are undisturbed. A flow-through device and process for using the biodeposition method to quantify the feeding of bivalve mollusks were modified from a land-based format for shipboard use by building a two-dimensional gimbal table around the device. Planimeter data reveal a minimal pitch and yaw of the chambers containing the test shellfish despite boat motion, the flow rates within the chambers remain constant, and operators are able to collect the biodeposits (feces and pseudofeces) with sufficient consistency to obtain accurate measurements of the bivalve clearance, filtration, selection, ingestion, rejection, and absorption at offshore shellfish aquaculture sites.

A flow-through device for using the biodeposition method to quantify filtration and feeding behavior of bivalve mollusks was modified for shipboard use. A two-dimensional gimbal table built around the device isolates the apparatus from boat motion, thereby allowing the accurate quantification of bivalve filtration variables at offshore shellfish aquaculture sites.

デザインと二枚貝のサスペンションが海で餌を定量化するための装置の使用

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves ...

Microalgae Cultivation and Biomass Quantification in a Bench-Scale Photobioreactor with Corrosive Flue Gases

Photobioreactors are illuminated cultivation systems for experiments on phototrophic microorganisms. These systems provide a sterile environment for microalgal cultivation with temperature, pH, and gas composition and flow rate control. At bench-scale, photobioreactors are advantageous to researchers studying microalgal properties, productivity, and growth optimization. At industrial scales, photobioreactors can maintain product purity and improve production efficiency. The video describes the preparation and use of a bench-scale photobioreactor for microalgal cultivation, including the safe use of corrosive gas inputs, and details relevant biomass measurements and biomass productivity calculations. Specifically, the video illustrates microalgal culture storage and preparation for inoculation, photobioreactor assembly and sterilization, biomass concentration measurements, and a logistic model for microalgal biomass productivity with rate calculations including maximum and overall biomass productivities. Additionally, since there is growing interest in experiments to cultivate microalgae using simulated or real waste gas emissions, the video will cover the photobioreactor equipment adaptations necessary to work with corrosive gases and discuss safe sampling in such scenarios.

Bench-scale, axenic cultivation facilitates microalgal characterization and productivity optimization before subsequent process scale-up. Photobioreactors provide the necessary control for reliable and reproducible microalgal experiments and can be adapted to safely cultivate microalgae with the corrosive gases (CO2, SO2, NO2) from municipal or industrial combustion emissions.

腐食性煙道ガスを用いたベンチスケール光バイオリアクターにおける微細藻類栽培とバイオマス定量

Photobioreactors are illuminated cultivation systems for experiments on phototrophic microorganisms. These systems provide a sterile environment for ...

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.

Gastrointestinal dysfunction remains a major cause of morbidity and mortality. Indeed, gastrointestinal (GI) motility in health and disease remains an area of productive research with over 1,400 published animal studies in just the last 5 years. Numerous techniques have been developed for quantifying smooth muscle activity of the stomach, small intestine, and colon. In vitro and ex vivo techniques offer powerful tools for mechanistic studies of GI function, but outside the context of the integrated systems inherent to an intact organism. Typically, measuring in vivo smooth muscle contractions of the stomach has involved an anesthetized preparation coupled with the introduction of a surgically placed pressure sensor, a static pressure load such as a mildly inflated balloon or by distending the stomach with fluid under barostatically-controlled feedback. Yet many of these approaches present unique disadvantages regarding both the interpretation of results as well as applicability for in vivo use in conscious experimental animal models. The use of dual element strain gages that have been affixed to the serosal surface of the GI tract has offered numerous experimental advantages, which may continue to outweigh the disadvantages. Since these gages are not commercially available, this video presentation provides a detailed, step-by-step guide to the fabrication of the current design of these gages. The strain gage described in this protocol is a design for recording gastric motility in rats. This design has been modified for recording smooth muscle activity along the entire GI tract and requires only subtle variation in the overall fabrication. Representative data from the entire GI tract are included as well as discussion of analysis methods, data interpretation and presentation.

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.

The in vivo measurement of smooth muscle contractions along the gastrointestinal tract of laboratory animals remains a powerful, though underutilized, technique. Flexible, dual element strain gages are not commercially available and require fabrication. This protocol describes the construction of reliable, inexpensive strain gages for acute or chronic implantation in rodents.

測定するための小型のデュアルエレメントひずみゲージの作製と移植<em&gt;インビボ</em&gt;げっ歯類における消化管収縮。

Gastrointestinal dysfunction remains a major cause of morbidity and mortality. Indeed, gastrointestinal (GI) motility in health and disease remains an ...

Impedance Pneumography for Minimally Invasive Measurement of Heart Rate in Late Stage Invertebrates

Temperatures in oceans are increasing rapidly as a consequence of widespread changes in world climates. As organismal physiology is heavily influenced by environmental temperature, this has the potential to alter thermal physiological performance in a variety of marine organisms. Using the American lobster (Homarus americanus) as a model organism, this protocol describes the use of impedance pneumography to understand how cardiac performance in late stage invertebrates changes under acute thermal stress. The protocol presents a minimally invasive technique that allows for real-time collection of heart rate during a temperature ramping experiment. Data are easily manipulated to generate an Arrhenius plot that is used to calculate Arrhenius break temperature (ABT), the temperature at which heart rate begins to decline with increasing temperatures. This technique can be used in a variety of late stage invertebrates (i.e., crabs, mussels, or shrimps). Although the protocol focuses solely on the impact of temperature on cardiac performance, it can be modified to understand the potential for additional stressors (e.g., hypoxia or hypercapnia) to interact with temperature to influence physiological performance. Thus, the method has potential for wide-ranging applications to further understand how marine invertebrates respond to acute changes in the environment.

Measuring heart rate during a thermal challenge provides insight into physiological responses of organisms as a consequence of acute environmental change. Using the American lobster (Homarus americanus) as a model organism, this protocol describes the use of impedance pneumography as a relatively noninvasive and nonlethal approach to measure heart rate in late stage invertebrates.

後期無脊椎動物における低侵襲性心拍数測定のためのインピーダンス肺撮影

Temperatures in oceans are increasing rapidly as a consequence of widespread changes in world climates. As organismal physiology is heavily influenced by ...

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice

Exercise training is an important strategy for maintaining health and preventing many chronic diseases. It is the first line of treatment recommended by international guidelines for patients suffering from cardiovascular diseases, more specifically, lower extremity artery diseases, where the patients' walking capacity is considerably altered, affecting their quality of life. 
Traditionally, both low continuous exercise and interval training have been used. Recently, supramaximal training has also been shown to improve athletes' performances via vascular adaptations, amongst other mechanisms. The combination of this type of training with hypoxia could bring an additional and/or synergic effect, which could be of interest for certain pathologies. Here, we describe how to perform supramaximal intensity training sessions in hypoxia on healthy mice at 150% of their maximal speed, using a motorized treadmill and a hypoxic box. We also show how to dissect the mouse in order to retrieve organs of interest, particularly the pulmonary artery, the abdominal aorta, and the iliac artery. Finally, we show how to perform ex vivo vascular function assessment on the retrieved vessels, using isometric tension studies.

High-intensity training in hypoxia is a protocol that has been proven to induce vascular adaptations potentially beneficial in some patients and to improve athletes&#39; repeated sprint ability. Here, we test the feasibility of training mice using that protocol and identify those vascular adaptations using ex vivo vascular function assessment.

激低酸素運動とマウスの血管機能評価

Exercise training is an important strategy for maintaining health and preventing many chronic diseases. It is the first line of treatment recommended by ...

行動学

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

The isolated microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of factors that control vessel diameter, and thus, perfusion resistance1-5. This is a classic experimental preparation that was, in large measure, initially described by Uchida et al.15 several decades ago. This initial description provided the basis for the techniques that was extensively modified and enhanced, primarily in the laboratory of Dr. Brian Duling at the University of Virginia6-8, and we present a current approach in the following pages. This preparation will specifically refer to the gracilis arteriole in a rat as the microvessel of choice, but the basic preparation can readily be applied to vessels isolated from nearly any other tissue or organ across species9-13. Mechanical (i.e., dimensional) changes in the isolated microvessels can easily be evaluated in response to a broad array of physiological (e.g., hypoxia, intravascular pressure, or shear) or pharmacological challenges, and can provide insight into mechanistic elements comprising integrated responses in an intact, although ex vivo, tissue. The significance of this method is that it allows for facile manipulation of the influences on the integrated regulation of microvessel diameter, while also allowing for the control of many of the contributions from other sources, including intravascular pressure (myogenic), autonomic innervation, hemodynamic (e.g., shear stress), endothelial dependent or independent stimuli, hormonal, and parenchymal influences, to provide a partial list. Under appropriate experimental conditions and with appropriate goals, this can serve as an advantage over in vivo or in situ tissue/organ preparations, which do not readily allow for the facile control of broader systemic variables. 
The major limitation of this preparation is essentially the consequence of its strengths. By definition, the behavior of these vessels is being studied under conditions where many of the most significant contributors to the regulation of vascular resistance have been removed, including neural, humoral, metabolic, etc. As such, the investigator is cautioned to avoid over-interpretation and extrapolation of the data that are collected utilizing this preparation. The other significant area of concern with regard to this preparation is that it can be very easy to damage cellular components such as the endothelial lining or the vascular smooth muscle, such that variable source of error can be introduced. It is strongly recommended that the individual investigator utilize appropriate measurements to ensure the quality of the preparation, both at the initiation of the experiment and periodically throughout the course of a protocol.

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

An ex vivo preparation is described for isolation of the largest gracilis muscle resistance arterioles for interrogation of both vascular responses to vasoactive stimuli and the assessment of basic structural properties via passive wall mechanics.

ザ ex vivoで</em血管反応性の調査のために>隔離された骨格微小血管の準備

The isolated  microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of  factors that control vessel ...

生物学

Mechano-Node-Pore Sensing: A Rapid, Label-Free Platform for Multi-Parameter Single-Cell Viscoelastic Measurements

Cellular mechanical properties are involved in a wide variety of biological processes and diseases, ranging from stem cell differentiation to cancer metastasis. Conventional methods for measuring these properties, such as atomic force microscopy (AFM) and micropipette aspiration (MA), capture rich information, reflecting a cell's full viscoelastic response; however, these methods are limited by very low throughput. High-throughput approaches, such as real-time deformability cytometry (RT-DC), can only measure limited mechanical information, as they are often restricted to single-parameter readouts that only reflect a cell's elastic properties. In contrast to these methods, mechano-node-pore sensing (mechano-NPS) is a flexible, label-free microfluidic platform that bridges the gap in achieving multi-parameter viscoelastic measurements of a cell with moderate throughput. A direct current (DC) measurement is used to monitor cells as they transit a microfluidic channel, tracking their size and velocity before, during, and after they are forced through a narrow constriction. This information (i.e., size and velocity) is used to quantify each cell's transverse deformation, resistance to deformation, and recovery from deformation. In general, this electronics-based microfluidic platform provides multiple viscoelastic cell properties, and thus a more complete picture of a cell's mechanical state. Because it requires minimal sample preparation, utilizes a straightforward electronic measurement (in contrast to a high-speed camera), and takes advantage of standard soft lithography fabrication, the implementation of this platform is simple, accessible, and adaptable to downstream analysis. This platform's flexibility, utility, and sensitivity have provided unique mechanical information on a diverse range of cells, with the potential for many more applications in basic science and clinical diagnostics.

Presented here is a method to mechanically phenotype single cells using an electronics-based microfluidic platform called mechano-node-pore sensing (mechano-NPS). This platform maintains moderate throughput of 1-10 cells/s while measuring both the elastic and viscous biophysical properties of cells.

メカノノードポアセンシング:マルチパラメータシングルセル粘弾性測定のための迅速でラベルフリーのプラットフォーム

Cellular mechanical properties are involved in a wide variety of biological processes and diseases, ranging from stem cell differentiation to cancer ...

ひずみゲージモニター (SGM) 研究室による日周サイクリング酸素分圧および pH 応答の二枚貝軟体動物の連続弁 Gape 測定

要約

さらに動画を探す

この動画の章

動物の行動観察のための溶存酸素を操作するための単純なアプローチ

トライリーフレットポリマーバルブの相対的な流体力学的評価のためのプロトコル

Quantitative and Temporal Control of Oxygen Microenvironment at the Single Islet Level

デザインと二枚貝のサスペンションが海で餌を定量化するための装置の使用

腐食性煙道ガスを用いたベンチスケール光バイオリアクターにおける微細藻類栽培とバイオマス定量

測定するための小型のデュアルエレメントひずみゲージの作製と移植

後期無脊椎動物における低侵襲性心拍数測定のためのインピーダンス肺撮影

激低酸素運動とマウスの血管機能評価

ザ ex vivoで隔離された骨格微小血管の準備

メカノノードポアセンシング:マルチパラメータシングルセル粘弾性測定のための迅速でラベルフリーのプラットフォーム

ひずみゲージ モニター (SGM) 研究室による日周サイクリング酸素分圧および pH 応答の二枚貝軟体動物の連続弁 Gape 測定

要約

さらに動画を探す

この動画の章

動物の行動観察のための溶存酸素を操作するための単純なアプローチ

トライリーフレットポリマーバルブの相対的な流体力学的評価のためのプロトコル

Quantitative and Temporal Control of Oxygen Microenvironment at the Single Islet Level

デザインと二枚貝のサスペンションが海で餌を定量化するための装置の使用

腐食性煙道ガスを用いたベンチスケール光バイオリアクターにおける微細藻類栽培とバイオマス定量

測定するための小型のデュアルエレメントひずみゲージの作製と移植

後期無脊椎動物における低侵襲性心拍数測定のためのインピーダンス肺撮影

激低酸素運動とマウスの血管機能評価

ザ ex vivoで隔離された骨格微小血管の準備

メカノノードポアセンシング:マルチパラメータシングルセル粘弾性測定のための迅速でラベルフリーのプラットフォーム

ひずみゲージモニター (SGM) 研究室による日周サイクリング酸素分圧および pH 応答の二枚貝軟体動物の連続弁 Gape 測定