Bu çalışmada, Boston Scientific Nöromodülasyon tarafından finanse edildi.

1. Giriş: Spinal kord stimülasyonu veya SCS, klinik Dr Norman Shealy kronik, inatçı ağrı (Shealy ve ark, 1967) olan hastalarda rahatlama sağlamak için bir girişimde dorsal sütun üzerinde ilk uyarımı elektrot implante, 1967 yılından bu yana uygulanan vardır. SCS &quot;yakın kapısı&quot; yüksek beyin merkezleri (ağrı sinyallerinin iletimi inhibe veya büyük miyelinli afferent sinirler dokunma ve basınç gibi duyular aracılık aktivasyonunun konumlandıran Gate Teorisi, klinik uygulama Melzack &amp; Cephe , 1965). SCS için Teknoloji, on yıl içinde gelişmiş dorsal sütun daha iyi canlandırmak için tasarlanmış daha güvenilir bir uyarı ekipmanları ile evrim geçirdi. Bu gelişmeler Anahtar nöroanatomi ve nörofizyoloji omurilik klinik elektrik stimülasyonu ile ilgili artan bir anlayış olmuştur. Bu anlayış, SCS sayısal modelleme ileri olmuştur. Nöron Hesaplamalı modelleme Hodgkin ve Huxley matematiksel model (Hodgkin ve Huxley, 1952) bu yana sinir uyarımı için temel mekanizmaları anlamak için kullanılır olmuştur. Sinir aktivitesi, hücre içi mevcut enjeksiyon ve hücre dışı potansiyel alanlar olarak uygulanan elektrik alanlar tarafından modüle. Ranck niteliksel bir akson çevresinde ekstrasellüler voltaj değişiklikleri (Ranck 1975) akson zarı bazı bölgelerinde depolarize ve diğerleri hyperpolarize neden nasıl tartışıldı. SCS için bir hesaplama modeli başlangıçta Coburn ve Sin (Coburn, 1980) tarafından geliştirilen ve anlamlı Struijk ve SCS üç boyutlu bir alan modeli (Holsheimer ve Struijk, 1988) Holsheimer gelişimi ile başlayan Holsheimer ve arkadaşları tarafından daha da derinleştirdi. Onların hesaplama modeli, dorsal sütun lifler (Struijk ve ark, 1992) eşikleri anatomik parametrelerin etkisi tahmin dorsal kök lifleri (Struijk ve ark, 1993b) uyarma potansiyeli tahmin ve BOS etkisi analiz klinik doğrulamaları (Holsheimer ve ark, 1995a;. Holsheimer ve ark, 1994 O ve ark, 1994) kalınlığı (Struijk ve ark, 1993a). Kök lifleri (Holsheimer ve ark üzerinde tercihli dorsal kolon liflerinin uyarılması lehine, modeli, iletişim boyutu ve aralık için en uygun parametreler (Holsheimer ve Wesselink, 1997 Holsheimer ve Struijk 1992) öne stimülasyon kurşun tasarım tasarım önemli bir rol oynamıştır. 1995b). 2. Yöntem: Matematiksel Model Tanımı Sonlu elemanlar matematiksel (FEM) modeli düşük torasik spinal kord ve çevresinin oluşturuldu. FEM modeli, spinal kord beyaz ve gri cevherde, beyin omurilik sıvısı, dura, epidural aralığa dokusu, vertebral kemik ve iki silindirik multicontact açar oluşuyordu. Her kurşun polimer (iletken olmayan alanları, 1 mm uzunluğunda) yalıtım 1mm uzunlukları ile ayrılmış sekiz silindirik platin-iridyum rehber (iletken alanları, 3mm uzunluğunda ve 1.25 mm çapında), oluşuyordu. Yol açan dura tepesinde dorsal konumlandırılmış ve simetrik, 1mm omurilik orta hat her iki tarafında idi. Modelde, beyin omurilik sıvısı tabakasının, kişileri ve omurilik dorsal yüzey (DCSF) arasında &quot;kalınlık&quot; 3.2mm belirtildi. Modelinin geometri gösterildiği Şekil 1A ve Tablo elektrik özdirençlerine verilir, ağırlıklı olarak edebiyat (Holsheimer, 2002; Wesselink ve ark, 1999) değerleri geliyor. Şekil 1B de gösterildiği gibi, elektrotlar nerede yakın bölgede bir yüksek yoğunluklu örgü hacmi, 1 milyonun üzerinde düğümler ile fileli. <img src="/files/ftp_upload/2443/2443fig1.jpg" alt="Şekil 1" /> Şekil 1, omurilik ve multicontact kurşun için FEM örgü anlatımı . (A) Bileşenleri ve model yapısı. (B) örgü modeli sadece yüksek yoğunluklu kısmı gösterilmiştir. Örgü değişken düğüm yoğunluğu bölüme segmente: kontaklar (≤ 300 mikron) yakın; izolatör, dura ve spinal kord (≤ 750 mikron), epidural aralığa (≤ 3000 mm) ve vertebra (≤ 5000 mm). <img src="/files/ftp_upload/2443/2443table1.jpg" alt="Tablo 1" /> Tablo 1: Direnç FEM etki değerleri (Holsheimer, 2002; Wesselink ve ark, 1999) ve modifikasyon (epidural aralık) klinik veriler maç. Omurilik geometrisi (Şekil 2), ilgili literatür kaynaklarından özellikleri bir arada kullanarak oluşturuldu. Struijk; kablosunun kesiti (Kameyama ve ark, 1996 Kameyama ark elde edildi, ve dorsal kök Struijk ve ark (DR) yörünge kabul edilmiştir.ve ark, 1993b). Dorsal kolon (DC) lifleri, düzenli ızgara (mediolateral yönü ve 100um dorsoventral yönde 200um bkz. Şekil 2A) yerleştirildi ve rostro yönde öngörülen. Her DR daha büyük çaplı bir &#39;anne&#39; fiber küçük çaplı (Şekil 2B) çatallı &#39;kızı&#39; liflerine bağlı olarak modellenmiştir. <img src="/files/ftp_upload/2443/2443fig2.jpg" alt="Şekil 2" /> Şekil 2 omurilik modeli yapısı. (A) omurilik ve dorsal kolon liflerinin yeri İşlemsel görünümü. (B) Dorsal kökleri bir anne fiber ve çatallı kızı lifleri oluşmaktadır. Ana fiber yörünge Struijk 1993 sayısallaştırılmış oldu. (C) omurilik ve DR lifleri üç boyutlu bir görüntü. Model Araştırılması Yol açar modeli içinde yerleştirilmiş sonra, iki tür uyarıcıları iki paralel kişiler için akımlar tanımlayarak hayata geçirildi. Tek bir kaynak sistemi için mevcut teslim etmek için üç olası yöntemleri vardı: a. b. soldaki temas mevcut c. her iki kontak akımının% 50 teslim en sağdaki kişi tüm güncel sağlar. Biz burada bu klinik uygulama gerçek olması muhtemel olsa da, iki rehber empedans, eşit kabul edilir unutmayın. Çok kaynaklı sistem için, her kişi, kişiler arasında% 1 artımlı değişiklikler denetlenebilir kendi akım kaynağı tanımlanmıştır. Diğer bir deyişle, iki kişilere teslim edilen toplam akım çok kaynaklı sistem, 10mA ise, her kişi için geçerli bu kadar uzun süre her kişi eşit 10mA üzerinden akımların toplamı olarak, toplam herhangi bir fraksiyonu belirtildi. Örneğin, en soldaki kişinin en sağdaki kişi ardından 3.2 mA teslim 6,8 mA teslim olabilir. Mevcut bu şekilde programlanmış çok kaynaklı sistem, 100 kesirli böler. Her sistem dorsal sütunlar içinde aktivasyon bölge hesaplamak için, aktive edici bir fonksiyon analizi yapıldı. Aktive fonksiyonu ekstrasellüler uyarıcı akımı, belirli bir elektrot ve lif geometrisi için sinir doku uygulanır transmembran potansiyel değişim bir yaklaşım. Aktivasyon bölgede aktive fonksiyonu (veya akson boyunca gerilimler sadece ikinci fark) (örneğin 0.1mV/mm2) önceden belirlenmiş bir eşik aşıldı modeli lif odağı olarak tanımlandı. Stimülasyon merkezi bir noktadan, 3-boyutlu aktivasyon bölgenin geometrik ağırlık merkezi olarak tanımlanan ve hesaplandı. Stimülasyon genlik belirlemek için, iki kontak monopolar yapılandırma katotlar (% 50 ve% 50 iki kontak negatif potansiyel) (model sınırlarından eşdeğer akım yoğunluğu ile teslim akım kaynaklı) belirlenmiştir. Stimülasyon genlik sonra aktive ilk lif (bu her zaman dorsal sütun fiber) gözlendi kadar iteratif artmış oldu. Bu ilk aktivasyon parestezi klinik ortamda hasta tarafından ilk algı ilişkilendirmek için kabul edildi. Modelde, mevcut 1.4 * (mA ilk fiber etkinleştirmek için) artmıştır ve aktivasyon ortaya çıkan bölgenin centroid hesaplandı. Tüm direksiyon adımları (100:0 - 0:100) sentroidler önceki adımda belirlenen genlik ile hesaplanmıştır. Centroid değişim ortalama çözünürlük geçerli adımları bölünmesiyle ağırlık merkezi konumu aralığı oldu. 3. Sonuç: Çift yol arasındaki mediolaterally stimülasyon direksiyon zaman, hesaplama modeli, her kişi için bağımsız akım kaynakları ile bir cihaz, tek bir kaynaktan sistemi (100 vs 3) göre, dorsal kolon üzerinde stimülasyonu daha merkezi noktaları hedef olduğunu tahmin ediyor. Bunun sonucu olarak, stimülasyon merkezi bir nokta çözünürlük ayarı çok kaynaklı sistemi ile 30 um, tek kaynak sistemleri (bkz. Şekil 3) ile karşılaştırıldığında yaklaşık 50 kat artış. <img src="/files/ftp_upload/2443/2443fig3.jpg" alt="Şekil 3" /> Şekil 3 hesaplama modeli şu tahminlerde yapar. A. Çift kurşun yapılandırma: 2.0 mm monopol stimülasyonu ile yol arasındaki ayrılık. (Ortalama 1 mm 2 mm kurşun ayırma ile bir adım boyutu) mediolaterally stimülasyon değişen tüm kişiler için tek bir paylaşılan güç kaynağı sağlayan B. Tek kaynak cihazlarının stimülasyon üç merkezi noktalara hedefleyebilir. C:% 1&#39;lik artışlarla veya 10 merkez noktaları mevcut fractionalizing zaman zaman% 10&#39;luk artışlarla (1% 0.02 mm bir adım boyutu fractionalizing her kişi dorsal sütun yanal 100 merkez noktaları hedef için özel bir güç kaynağı olan bir cihaz adımları ve ortalama% 10 adımlar için 0.2 mm).

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Yazarlar, Boston Scientific Nöromodülasyon çalışanlarıdır.

Yeteneği yüksek çözünürlüklü dorsal sütun merkezi stimülasyon bölgelere parestezi-ağrı örtüşme hastalarda daha iyi optimizasyonu için izin verebilir. Yani, belirli bir hasta, dorsal sütunları aktivasyon bölgede ağrılı bölgelerde kapsama alanı en üst düzeye çıkarmak için odaklanmış olabilir ise en aza indirir yan etkiler (motor veya otonom istenmeyen yerlerde parestezi veya yaratabilir istenmeyen elyaf, uyarılması nedeniyle etkiler).

<ul><li> NÖRON ( <a href="http://www.neuron.yale.edu">http://www.neuron.yale.edu</a> ) </li><li> ANSYS (Canonsburg, <a href="http://www.ansys.com">http://www.ansys.com</a> ) </li><li> Matlab (Natick, MA, <a href="http://www.mathworks.com">http://www.mathworks.com</a> ) </li></ul>

dorsal column steerability with dual parallel leads using dedicated power sources:  a computational model

Spinal kord stimülasyonu (SCS), ağrılı vücut bölgeler üzerinde stimülasyonuna parestezi konkordans terapötik etkinliği için gerekli bir koşul. Hasta ağrı desenleri eşsiz olabilir, ortak bir stimülasyon yapılandırması yerleştirme dorsal epidural aralığa paralel olarak iki yol açar. Bu yapı mediolaterally iyi ağrı parestezi üst üste elde etmek için dorsal sütun üzerinde stimülasyon mevcut direksiyon esneklik sağlar. Bir (1) tek bir kaynak sistemi kullanarak, doğru bir lif çap dağılımı ile matematiksel bir model kullanarak, çift paralel yeteneği okudu bitişik ikili paralel kontaklar arasında uyarılması yönlendirmek için yol açar, ve (2) bir çok kaynak sistemi Her bir kişi için mevcut kaynak adamıştır. Epidural konumlandırılan çift paralel düşük torasik omurilik hacmi iletken modeli (2 mm ayırma) perkütan yol açan ilk yaratılan, ve elektrik alanında ANSYS, sonlu elemanlar modelleme aracı kullanılarak hesaplandı. 10 um elyaflar için aktive fonksiyonu ikinci dorsal sütun sinir lifleri Ranvier düğümleri boyunca ekstrasellüler potansiyeli fark olarak hesaplanmıştır. Aktivasyonu (VOA) ve VOA merkez noktası hacmi, önceden belirlenmiş bir eşik aktive fonksiyonu kullanılarak hesaplanmıştır. Bu model çift 8 temas stimülasyon kablolarında özel bir güç kaynağı sistemleri karşı tek bir kaynaktan alan direksiyon sonuçları karşılaştırıldı. Çok kaynak sistemi tek bir kaynaktan sistemi (100 vs 3) ve mediolateral direksiyon için ortalama direksiyon adım daha dorsal sütun üzerinde stimülasyon daha merkezi noktalara hedef tahmin modeli çok kaynak sistemleri vs 1 mm için 0,02 mm tek kaynak sistemleri için, 50 kat artış. Yeteneği yüksek çözünürlüklü dorsal sütun merkezi stimülasyon bölgelere parestezi-ağrı örtüşme hastalarda daha iyi optimizasyonu için izin verebilir.

Watch this Scientific Journal Video about Dorsal Column Steerability with Dual Parallel Leads using Dedicated Power Sources:  A Computational Model at JoVE.com

Dorsal Column Steerability with Dual Parallel Leads using Dedicated Power Sources:  A Computational Model

Spinal kord stimülasyonu bir matematiksel model kullanarak, biz (her kişi için bağımsız güç kaynakları ile bir çok kaynak sistemi, dorsal kolon üzerinde stimülasyonu daha merkezi bir nokta (100 vs 3) hedef olduğunu buldu ve 50 kat daha fazla alan direksiyon çözünürlük 0.02mm - 1mm), tek bir kaynak sistemi daha.

Atanmış Güç Kaynakları İkili Paralel Talepler Dorsal Sütun direksiyon hakimiyeti: Hesaplamalı Modeli

In spinal cord stimulation (SCS), concordance of stimulation-induced paresthesia over painful body regions is a necessary condition for therapeutic ...

dorsal-column-steerability-with-dual-parallel-leads-using-dedicated

Research

JoVE Journal

Medicine

11.8K Görüntüleme.  Neuromodulation. Spinal kord stimülasyonu bir matematiksel model kullanarak, biz (her kişi için bağımsız güç kaynakları ile bir çok kaynak sistemi, dorsal kolon üzerinde stimülasyonu daha merkezi bir nokta (100 vs 3) hedef olduğunu buldu ve 50 kat daha fazla alan direksiyon çözünürlük 0.02mm - 1mm), tek bir kaynak sistemi daha.

Video: Dorsal Column Steerability with Dual Parallel Leads using Dedicated Power Sources:  A Computational Model

A Novel Capsulorhexis Technique Using Shearing Forces with Cystotome

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye.
Method:
Our technique involves creating the initial anterior capsular tear with a cystotome to raise a flap. The flap left unfolded on the lens surface. The cystotome tip is tilted horizontally and is engaged on the flap near the leading edge of the tear. The cystotome is moved in a circular fashion to direct the vector forces. The loose flap is constantly swept towards the centre so that it does not obscure the view on the tearing edge.
Results:
Our technique has the advantage of reducing corneal wound distortion and subsequent anterior chamber collapse. The capsulorhexis flap is moved away from the tear leading edge allowing better visualisation of the direction of tear. This technique offers superior control of the capsulorhexis by allowing the surgeon to change the direction of the tear to achieve the desired capsulorhexis size.
Conclusions:
The EYESI Surgical Simulator is a realistic training platform for surgeons to practice complex capsulorhexis techniques. The shearing forces technique is a suitable alternative and in some cases a far better technique in achieving the desired capsulorhexis.

This video demonstrates a novel capsulorhexis technique in modern cataract surgery. Capsulorhexis is the most difficult and important part of phacoemulsification surgery.

Cystotome ile Makaslama Kuvvetleri kullanma Roman kapsüloreksis Tekniği

Purpose:
To demonstrate a capsulorhexis technique using predominantly shearing forces with a cystotome on a virtual reality simulator and on a human eye....

Tıp

In vivo Dual Substrate Bioluminescent Imaging

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate since the advent of in vivo bioluminescent imaging technologies 1-3. Indeed, the ability to locate and quantify tumor growth longitudinally in a single cohort of animals to completion of the study as opposed to sacrificing individual groups of animals at specific assay times has revolutionized how researchers investigate breast cancer metastasis. Unfortunately, current methodologies preclude the real-time assessment of critical changes that transpire in cell signaling systems as breast cancer cells (i) evolve within primary tumors, (ii) disseminate throughout the body, and (iii) reinitiate proliferative programs at sites of a metastatic lesion. However, recent advancements in bioluminescent imaging now make it possible to simultaneously quantify specific spatiotemporal changes in gene expression as a function of tumor development and metastatic progression via the use of dual substrate luminescence reactions. To do so, researchers take advantage for two light-producing luciferase enzymes isolated from the firefly (Photinus pyralis) and sea pansy (Renilla reniformis), both of which react to mutually exclusive substrates that previously facilitated their wide-spread use in in vitro cell-based reporter gene assays 4. Here we demonstrate the in vivo utility of these two enzymes such that one luminescence reaction specifically marks the size and location of a developing tumor, while the second luminescent reaction serves as a means to visualize the activation status of specific signaling systems during distinct stages of tumor and metastasis development. Thus, the objectives of this study are two-fold. First, we will describe the steps necessary to construct dual bioluminescent reporter cell lines, as well as those needed to facilitate their use in visualizing the spatiotemporal regulation of gene expression during specific steps of the metastatic cascade. Using the 4T1 model of breast cancer metastasis, we show that the in vivo activity of a synthetic Smad Binding Element (SBE) promoter was decreased dramatically in pulmonary metastasis as compared to that measured in the primary tumor 4-6. Recently, breast cancer metastasis was shown to be regulated by changes within the primary tumor microenvironment and reactive stroma, including those occurring in fibroblasts and infiltrating immune cells 7-9. Thus, our second objective will be to demonstrate the utility of dual bioluminescent techniques in monitoring the growth and localization of two unique cell populations harbored within a single animal during breast cancer growth and metastasis.

In vivo Dual Substrate Bioluminescent Imaging

Herein we describe the methods to construct, visualize, and quantify the bioluminescent reactions of both firefly and renilla luciferase enzymes expressed in metastatic breast cancer cells during their growth and metastasis in vivo.

Vivo Çift Yüzey Bioluminescent Imaging&#39;de

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate ...

Deep Neuromuscular Blockade Leads to a Larger Intraabdominal Volume During Laparoscopy

Shoulder pain is a commonly reported symptom following laparoscopic procedures such as myomectomy or hysterectomy, and recent studies have shown that lowering the insufflation pressure during surgery may reduce the risk of post-operative pain. In this pilot study, a method is presented for measuring the intra-abdominal space available to the surgeon during laproscopy, in order to examine whether the relaxation produced by deep neuromuscular blockade can increase the working surgical space sufficiently to permit a reduction in the CO2 insufflation pressure. Using the laproscopic grasper, the distance from the promontory to the skin is measured at two different insufflation pressures: 8 mm Hg and 12 mm Hg. After the initial measurements, a neuromuscular blocking agent (rocuronium) is administered to the patient and the intra-abdominal volume is measured again. Pilot data collected from 15 patients shows that the intra-abdominal space at 8 mm Hg with blockade is comparable to the intra-abdominal space measured at 12 mm Hg without blockade. The impact of neuromuscular blockade was not correlated with patient height, weight, BMI, and age. Thus, using neuromuscular blockade to maintain a steady volume while reducing insufflation pressure may produce improved patient outcomes.

This article presents a method for measuring the working abdominal volume during laproscopic myomectomy using the surgical grasper, and applies this technique to obtain pilot data on whether deep neuromuscular blockade (NMB) can enable the use of lower insufflation pressure. Reduced insufflation pressure during laproscopic surgery has been shown to reduce post-operative pain, and thus the use of NMB during surgery may enable improved patient outcomes.

Derin Nöromusküler Abluka Laparoskopi sırasında Büyük Karın İçi Ses yol açar

Shoulder pain is a commonly reported symptom following laparoscopic procedures such as myomectomy or hysterectomy, and recent studies have shown that ...

Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are still occurring, particularly in reconstructive flap surgery. Multiple experimental flap models have been developed to analyze underlying causes and mechanisms and to investigate treatment strategies to prevent ischemic complications. The limiting factor of most models is the lacking possibility to directly and repetitively visualize microvascular architecture and hemodynamics. The goal of the protocol was to present a well-established mouse model affiliating these before mentioned lacking elements. Harder et al. have developed a model of a musculocutaneous flap with a random perfusion pattern that undergoes acute persistent ischemia and results in ~50% necrosis after 10 days if kept untreated. With the aid of intravital epi-fluorescence microscopy, this chamber model allows repetitive visualization of morphology and hemodynamics in different regions of interest over time. Associated processes such as apoptosis, inflammation, microvascular leakage and angiogenesis can be investigated and correlated to immunohistochemical and molecular protein assays. To date, the model has proven feasibility and reproducibility in several published experimental studies investigating the effect of pre-, peri- and postconditioning of ischemically challenged tissue.

The window of the murine dorsal skinfold chamber presented visualizes a zone of acute persistent ischemia of a musculocutaneous flap. Intravital epi-fluorescence microscopy permits for direct and repetitive assessment of the microvasculature and quantification of hemodynamics. Morphologic and hemodynamic results can further be correlated with histological and molecular analyses.

Mouse Dorsal Skinfold Odası&#39;nda İskemik Doku Yaralanması: Bir Cilt Flap Model Akut Kalıcı iskemisi Araştırma

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are ...

Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including Parkinson's and Huntington's can disrupt it. People with Parkinson's disease, for example, tend to have increased saccadic latencies. Consequently, the quantitative measurement of saccadic eye movements has received considerable attention as a potential biomarker for neurodegenerative conditions. A lot more can be learned about the brain in both health and disease by observing what happens to eye movements when the function of specific brain areas is perturbed. Deep brain stimulation is a surgical intervention used for the management of a range of neurological conditions including Parkinson's disease, in which stimulating electrodes are placed in specific brain areas including several sites in the basal ganglia. Eye movement measurements can then be made with the stimulator systems both off and on and the results compared. With suitable experimental design, this approach can be used to study the pathophysiology of the disease being treated, the mechanism by which DBS exerts it beneficial effects, and even aspects of normal neurophysiology.

This paper describes the use of quantitative measurement of eye movements in conjunction with stimulation of focal areas of the deep brain in order to study physiology, pathophysiology, and the mechanisms of deep brain stimulation.

Derin Beyin Uyarım ile Saccadometry kullanarak normal ve patolojik beyin fonksiyonlarını incelemek için

The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

İzometrik Contractility ölçüm tel Myography kullanarak fare mezenterik arter

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Murine Model of Central Venous Stenosis using Aortocaval Fistula with an Outflow Stenosis

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ligation of the inferior vena cava (IVC) in the outflow of the fistula, mimicking central venous stenosis. Technical aspects of this model are introduced. The aorta and IVC are exposed, following an abdominal incision. The infra-renal aorta and IVC are dissected for proximal clamping, and the distal aorta is exposed for puncture. The IVC at the midpoint between the left renal vein and the aortic bifurcation is carefully dissected to place an 8-0 suture beneath the IVC. After clamping the aorta and IVC, an AVF is created by puncturing the infra-renal aorta through both walls into the IVC with a 25 G needle, followed by ligating a 22 G intra-venous (IV) catheter and IVC together. The catheter is then removed, creating a reproducible venous stenosis without occlusion. The aorta and IVC are unclamped after confirming primary hemostasis. This novel model of central vein stenosis is easy to perform, reproducible, and will facilitate studies on AVF failure.

An aortocaval fistula was created by puncturing the murine infra-renal aorta through both walls into the inferior vena cava and was followed by creation of a stenosis in its outflow via partial ligation of the inferior vena cava. This reproducible model can be used to study central venous stenosis.

Bir outflow stenozu ile Aokaval fistül kullanarak Merkezi venöz stenozis murine modeli

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ...

A Porcine Corneal Endothelial Organ Culture Model Using Split Corneal Buttons

Experimental research on corneal endothelial cells is associated with several difficulties. Human donor corneas are scarce and rarely available for experimental investigations as they are normally needed for transplantation. Endothelial cell cultures often do not translate well to in vivo situations. Due to the biostructural characteristics of non-human corneas, stromal swelling during cultivation induces substantial corneal endothelial cell loss, which makes it difficult to perform cultivation for an extended period of time. Deswelling agents such as dextran are used to counteract this response. However, they also cause significant endothelial cell loss. Therefore, an ex vivo organ culture model not requiring deswelling agents was established. Pig eyes from a local slaughterhouse were used to prepare split corneal buttons. After partial corneal trephination, the outer layers of the cornea (epithelium, bowman layer, parts of the stroma) were removed. This significantly reduces corneal endothelial cell loss induced by massive stromal swelling and Descemet&#39;s membrane folding throughout longer cultivation periods and improves general preservation of the endothelial cell layer. Subsequent complete corneal trephination was followed by the removal of the split corneal button from the remaining eye bulb and cultivation. Endothelial cell density was assessed at follow-up times of up to 15 days after preparation (i.e., days 1, 8, 15) using light microscopy. The preparation technique used allows a better preservation of the endothelial cell layer enabled by less stromal tissue swelling, which results in slow and linear decline rates in split corneal buttons comparable to human donor corneas. As this standardized organo-typically cultivated research model for the first time allows a stable cultivation for at least two weeks, it is a valuable alternative to human donor corneas for future investigations of various external factors with regards to their effects on the corneal endothelium.

Here, a step-by-step protocol for the preparation and cultivation of porcine split corneal buttons is presented. As this organo-typically cultivated organ culture model shows cell death rates within 15 days, comparable to human donor corneas, it represents the first model allowing long-term cultivation of non-human corneas without adding toxic dextran.

Split Korneal Düğmeleri Kullanarak Bir Domuz Korneal Endotel Organ Kültür Modeli

Experimental research on corneal endothelial cells is associated with several difficulties. Human donor corneas are scarce and rarely available for ...

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function relationships at the joint level remain challenging to quantify due to difficulties in accurately measuring dynamic joint motion. The soft tissue artifact errors inherent in optical skin marker motion capture are exacerbated by the depth of the hip joint within the body and the large mass of soft tissue surrounding the joint. Thus, the complex relationship between bone shape and hip joint kinematics is more difficult to study accurately than in other joints. Herein, a protocol incorporating computed tomography (CT) arthrography, three-dimensional (3D) reconstruction of volumetric images, dual fluoroscopy, and optical motion capture to accurately measure the dynamic motion of the hip joint is presented. The technical and clinical studies that have applied dual fluoroscopy to study form-function relationships of the hip using this protocol are summarized, and the specific steps and future considerations for data acquisition, processing, and analysis are described.

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture.

In Vivo Çift Floroskopi Kullanılarak Dinamik Ağırlık Taşıyan Faaliyetler Sırasında Kalça Arthrokinematics Nicelliği

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function ...

Modified Posterior Vertebral Column Resection for Patients with Thoracolumbar Kyphotic Deformity

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may cause severe thoracolumbar kyphotic deformity, often accompanied by intractable low back pain or compression of the spinal cord, leading to severe neurological symptoms or even paralysis. If conservative treatment cannot relieve the symptoms or correct the deformities, surgical treatment is usually needed. For severe kyphotic deformity, reconstruction of the physiological curvature and rigid fixation determine the prognosis of the patients. Osteotomy and orthopedics are the standard procedure for deformities with severe compression of the front and middle column, but the trauma to the patients is high, with a long operation time and massive blood loss. To avoid these disadvantages, we have developed a modified technique to remove the diseased vertebra unilaterally. In this technique, we use a modified trephine to resect the vertebral columns like in the pedicle screw technique by adding a locking instrument that can restrict the trephine to lower the risk of osteotomy and shorten the surgery time and blood loss.

We describe a modified technique for resecting the posterior vertebral column unilaterally based on a modified trephine for patients with thoracolumbar kyphotic deformity.

Torakolomber Kifotik Deformiteli Hastalarda Modifiye Posterior Vertebral Kolon Rezeksiyonu

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may ...