The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme [FP7/2007-2013] / ERC grant agreement [337333]. The research of SvV and GJB is supported by a VIDI grant [91711384] from ZonMw, the Netherlands Organization for Health Research and Development.

<ol>
	<li>Vander Kolk, A. G., Hendrikse, J., Zwanenburg, J. J., Visser, F., Luijten, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+applications+of+7+T+MRI+in+the+brain.">Clinical applications of 7 T MRI in the brain.</a> Eur J Radiol. 82 (5), 708-718 (2013).</li><li>Pantoni, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+small+vessel+disease:+from+pathogenesis+and+clinical+characteristics+to+therapeutic+challenges.">Cerebral small vessel disease: from pathogenesis and clinical characteristics to therapeutic challenges.</a> Lancet Neurol. 9, 689-701 (2010).</li><li>Gouw, A. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneity+of+small+vessel+disease:+a+systematic+review+of+MRI+and+histopathology+correlations.">Heterogeneity of small vessel disease: a systematic review of MRI and histopathology correlations.</a> J Neurol Neurosurg Psychiatry. 82 (2), 126-135 (2011).</li><li>Smith, E. E., Schneider, J. A., Wardlaw, J. M., Greenberg, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+microinfarcts:+the+invisible+lesions.">Cerebral microinfarcts: the invisible lesions.</a> Lancet Neurol. 11, 272-282 (2012).</li><li>Brundel, M., de Bresser, J., van Dillen, J. J., Kappelle, L. J., Biessels, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+microinfarcts:+a+systematic+review+of+neuropathological+studies.">Cerebral microinfarcts: a systematic review of neuropathological studies.</a> J. Cereb. Blood Flow Metab. 32 (3), 425-436 (2012).</li><li>Van Veluw, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+detection+of+cerebral+cortical+microinfarcts+with+high-resolution+7T+MRI.">In vivo detection of cerebral cortical microinfarcts with high-resolution 7T MRI.</a> J Cereb Blood Flow Metab. 33 (3), 322-329 (2013).</li><li>Van Veluw, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+spectrum+of+MR+detectable+cortical+microinfarcts;+a+classification+study+with+7+tesla+post-mortem+MRI+and+histopathology.">The spectrum of MR detectable cortical microinfarcts; a classification study with 7 tesla post-mortem MRI and histopathology.</a> J Cereb Blood Floow Metab. Jan. 21, 10-1038 (2015).</li><li>Van Duijn, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MRI+artifacts+in+human+brain+tissue+after+prolonged+formalin+storage.">MRI artifacts in human brain tissue after prolonged formalin storage.</a> Magn Reson Med. 65 (6), 1750-1758 (2011).</li><li>Van Veluw, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cortical+microinfarcts+on+3T+MRI:+clinical+correlates+in+memory-clinic+patients.">Cortical microinfarcts on 3T MRI: clinical correlates in memory-clinic patients.</a> Alzheimers Dement. 5, 10-1016 (2015).</li><li>Van Dalen, J. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cortical+microinfarcts+detected+in+vivo+on+3+Tesla+MRI:+clinical+and+radiological+correlates.">Cortical microinfarcts detected in vivo on 3 Tesla MRI: clinical and radiological correlates.</a> Stroke. 46 (1), 255-257 (2015).</li><li>Vander Kolk, A. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+intracranial+atherosclerotic+vessel+wall+using+7T+MRI:+initial+comparison+with+histopathology.">Imaging the intracranial atherosclerotic vessel wall using 7T MRI: initial comparison with histopathology.</a> AJNR Am J Neuroradiol. 36 (4), 694-701 (2015).</li><li>Visser, F., Zwanenburg, J. J., Hoogduin, J. M., Luijten, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+magnetization-prepared+3D-FLAIR+imaging+at+7.0+Tesla.">High-resolution magnetization-prepared 3D-FLAIR imaging at 7.0 Tesla.</a> Magn Reson Med. 64 (1), 194-202 (2010).</li><li>Brundel, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+prevalence+of+cerebral+microbleeds+at+7Tesla+MRI+in+patients+with+early+Alzheimer&#8217;s+disease.">High prevalence of cerebral microbleeds at 7Tesla MRI in patients with early Alzheimer&#8217;s disease.</a> J Alzheimers Dis. 31 (2), 259-263 (2012).</li><li>Kuijf, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+cortical+cerebral+microinfarcts+in+7.0+T+MR+images.">Detecting cortical cerebral microinfarcts in 7.0 T MR images.</a> IEEE International Symposium on Biomedical Imaging. , 982-985 (2013).</li></ol>

The authors have nothing to disclose.

جذبت نظام معلومات إدارة الشركات اهتماما متزايدا خلال السنوات القليلة الماضية. وقد حددت وهناك مجموعة متزايدة من الأدلة المستمدة من دراسات التشريح نظام معلومات إدارة الشركات كمساهمين المهم إلى التدهور المعرفي المرتبط بالسن والخرف 4،5. نظام معلومات إدارة الشركا...

تطبيق المجال فائقة 7 تسلا (T) MRI في الدراسات المريض يسير بخطى حثيثة 1. يقدم هذه الورقة تطبيق التمثيلي 7T MRI في سياق الأمراض الدماغية الوعائية في الدماغ البشري الشيخوخة. الأمراض الدماغية الوعائية هو سبب رئيسي من التدهور المعرفي والعته. هذه المساهمة الأوعية الدموية إلى الخرف ينطوي في كثير من الأحيان في الأوعية الصغيرة في الدماغ، مثل الشرايين والأوردة الصغيرة، والشعيرات الدموية. وبالتالي، فإنه يشار إلى المرض الدماغي كما صغيرة الأوعية الدموية (SVD) 2. لأن السفن الصغيرة الدماغية هي صغيرة جدا لالتقاط مع التصوير بالرنين المغناطيسي التقليدية، إلا أن عواقب SVD - أي إصابة الأنسجة الناتجة - يمكن تصور. وهذا يشمل hyperintensities المادة البيضاء، microbleeds الدماغية، وعوائق الجوبي 3. المظاهر الهامة الأخرى SVD هي microinfarcts الدماغي (نظام معلومات إدارة الشركات) 4. وتبلغ دراسات التشريح ارتفاع معدل انتشار نظام معلومات إدارة الشركات في VASCجزيئية العته، ومرض الزهايمر 5. ولكن نظرا لصغر حجمهما (تتراوح بين 50 ميكرون إلى بضعة ملم) يهربن من الكشف على التصوير بالرنين المغناطيسي التقليدية 4،5. يوفر 7T MRI صور عالية الدقة مع تحسن الإشارة إلى الضوضاء ونسبة التباين، والتي يمكن من اكتشاف بعض الهياكل والآفات خارج حدود كشف التصوير بالرنين المغناطيسي التقليدية. ولذلك انصب هذه التقنية للكشف عن نظام معلومات إدارة الشركات. لتحديد نظام معلومات إدارة الشركات ممكن، وكثير في الجسم الحي بالاشعة 7T MRI تم عرض سابقا للآفات مع أحجام &lt;5 مم والتصوير خصائص تتفق مع خصائص الدماغية. يمكن أن يعتمد عليه يتم تحديد هذه الآفات في القشرة. وكانت هذه الآفات ممدود التنسيق hyperintense على 7T FLAIR (voxels 0.8 مم الخواص)، يقتصر على القشرة ويبدو أن تمتد من السطح القشري، hyperintense على T2 (voxels 0.7 مم الخواص)، وhypointense على T1 (1.0 مم voxels الخواص). وأكد أن هذه الآفات كانت القشرية باستخدام نظام معلومات إدارة الشركاتMR الموجهة نهج التشريح المرضي في مرحلة ما بعد الوفاة البشري 6،7 أنسجة المخ. هنا، يتم تقديم بروتوكول MRI خارج الحي الذي تم استخدامه في دراسات سابقة للتحقق من صحة الأنسجة من نظام معلومات إدارة الشركات القشرية. ثانيا، يتم توفير مبادئ توجيهية لتقييم نظام معلومات إدارة الشركات القشرية على المجراة 7T MRI. وأخيرا، فقد ترجمت تقييم نظام معلومات إدارة الشركات القشرية على 7T لأكثر المتاحة على نطاق واسع 3T MRI، ويتم توفير مبادئ توجيهية كيفية التعرف على نظام معلومات إدارة الشركات القشرية على 3T MRI.

<table border="0">
	<tbody>
		<tr>
			<td>Fomblin / Galden PFPE</td>
			<td>Solvay Solexis, Bollate, Italy</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>7T MR system</td>
			<td>Philips Healthcare, Cleveland, OH, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>32-channel receive head coil</td>
			<td>Nova Medical, Wilmington, MA, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>MeVisLab</td>
			<td>MeVis Medical Solutions AG, Bremen, Germany</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

assessing cortical cerebral microinfarcts on high resolution mr images

microinfarcts الدماغي هي النتائج المتكررة في الدماغ البشري بعد الوفاة، وترتبط إلى التدهور المعرفي والعته. ونظرا لصغر حجمهما أنه يمثل تحديا لدراستها على التصوير بالرنين المغناطيسي السريرية. وقد تجلى مؤخرا أن microinfarcts القشرية يمكن أن يصور مع الماسحات الضوئية باستخدام التصوير بالرنين المغناطيسي شدة المجال المغناطيسي عالية (7T). وبناء على هذه التجربة، فإن نسبة من هذه الآفات هي أيضا واضحة على دقة أقل 3T MRI. وقد أيد هذه النتائج مع فيفو السابقين التصوير من بعد الوفاة أنسجة المخ البشري، يرافقه التحقق من الأنسجة microinfarcts القشرية ممكن. هنا يرد بروتوكول التصوير خارج الحي، لغرض التحقق من صحة احظ MR الدماغي الاوعية الدموية الدقيقة علم الأمراض النسيجي مع التقييم. وعلاوة على ذلك، يتم توفير مبادئ توجيهية لتقييم microinfarcts القشرية على حد سواء في الجسم الحي 7T و3T MR الصور. وتوفر هذه المبادئ التوجيهية الباحثين ثإيث أداة لتقييم microinfarcts القشرية على الصور في الجسم الحي من عينات المرضى بشكل اكبر، لمواصلة كشف أهمية سريرية في التدهور المعرفي والعته، وإقامة هذه الآفات والعلامات البيولوجية جديدة من مرض الأوعية الصغيرة في الدماغ.

انطباعا على دقة عالية وصورة عالية الجودة من تسلسل خارج الحي المكتسبة في تقدم 7T <a href="https://www.jove.com/files/ftp_upload/53125/53125fig4.mp4" target="_blank">هنا (الشكل 4).</a> هذا هو T2 3D * المرجحة فحص خارج الحي، مع قرار موحد الخواص من 0.18 ملم. وقد اشتق الأنسجة من الإناث الجنونية من العمر 84 القديم...

Watch this Scientific Journal Video about Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images at JoVE.com

Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images

A عالية الدقة تعرض خارج الحي 7T MR بروتوكول التصوير، لأداء MR الموجهة التحقق من صحة الأنسجة من الاوعية الدموية الدقيقة علم الأمراض في مرحلة ما بعد الوفاة أنسجة المخ الإنسان. وعلاوة على ذلك، يتم توفير مبادئ توجيهية لتقييم microinfarcts القشرية على المجراة 7T وكذلك الصور 3T MR.

تقييم القشرية الدماغية Microinfarcts على ارتفاع القرار MR الصور

Cerebral microinfarcts are frequent findings in the post-mortem human brain, and are related to cognitive decline and dementia. Due to their small sizes ...

assessing-cortical-cerebral-microinfarcts-on-high-resolution-mr-images

Research

JoVE Journal

Medicine

13.3K Views.  University Medical Center Utrecht.  A عالية الدقة تعرض خارج الحي 7T MR بروتوكول التصوير، لأداء MR الموجهة التحقق من صحة الأنسجة من الاوعية الدموية الدقيقة علم الأمراض في مرحلة ما بعد الوفاة أنسجة المخ الإنسان. وعلاوة على ذلك، يتم توفير مبادئ توجيهية لتقييم microinfarcts القشرية ع...

Video: Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized.  The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed. 

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine heart.

عالية التردد عالية الدقة ضربات القلب : أول دليل على عدم تكرار القياس الغازية من سلالة عضلة القلب ، انقباض ، وقلس التاجي في القلب الإسكيمية ، فأري إشباعها

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

How to Measure Cortical Folding from MR Images: a Step-by-Step Tutorial to Compute Local Gyrification Index

Cortical folding (gyrification) is determined during the first months of life, so that adverse events occurring during this period leave traces that will be identifiable at any age. As recently reviewed by Mangin and colleagues2, several methods exist to quantify different characteristics of gyrification. For instance, sulcal morphometry can be used to measure shape descriptors such as the depth, length or indices of inter-hemispheric asymmetry3. These geometrical properties have the advantage of being easy to interpret. However, sulcal morphometry tightly relies on the accurate identification of a given set of sulci and hence provides a fragmented description of gyrification. A more fine-grained quantification of gyrification can be achieved with curvature-based measurements, where smoothed absolute mean curvature is typically computed at thousands of points over the cortical surface4. The curvature is however not straightforward to comprehend, as it remains unclear if there is any direct relationship between the curvedness and a biologically meaningful correlate such as cortical volume or surface. To address the diverse issues raised by the measurement of cortical folding, we previously developed an algorithm to quantify local gyrification with an exquisite spatial resolution and of simple interpretation. Our method is inspired of the Gyrification Index5, a method originally used in comparative neuroanatomy to evaluate the cortical folding differences across species. In our implementation, which we name local Gyrification Index (lGI1), we measure the amount of cortex buried within the sulcal folds as compared with the amount of visible cortex in circular regions of interest. Given that the cortex grows primarily through radial expansion6, our method was specifically designed to identify early defects of cortical development.
In this article, we detail the computation of local Gyrification Index, which is now freely distributed as a part of the FreeSurfer Software (<a href="http://surfer.nmr.mgh.harvard.edu/">http://surfer.nmr.mgh.harvard.edu/</a>, Martinos Center for Biomedical Imaging, Massachusetts General Hospital). FreeSurfer provides a set of automated reconstruction tools of the brain's cortical surface from structural MRI data. The cortical surface extracted in the native space of the images with sub-millimeter accuracy is then further used for the creation of an outer surface, which will serve as a basis for the lGI calculation. A circular region of interest is then delineated on the outer surface, and its corresponding region of interest on the cortical surface is identified using a matching algorithm as described in our validation study1. This process is repeatedly iterated with largely overlapping regions of interest, resulting in cortical maps of gyrification for subsequent statistical comparisons (Fig. 1). Of note, another measurement of local gyrification with a similar inspiration was proposed by Toro and colleagues7, where the folding index at each point is computed as the ratio of the cortical area contained in a sphere divided by the area of a disc with the same radius. The two implementations differ in that the one by Toro et al. is based on Euclidian distances and thus considers discontinuous patches of cortical area, whereas ours uses a strict geodesic algorithm and include only the continuous patch of cortical area opening at the brain surface in a circular region of interest.

Measuring gyrification (cortical folding) at any age represents a window into early brain development. Hence, we previously developed an algorithm to measure local gyrification at thousands of points over the hemisphere1. In this paper, we detail the computation of this local gyrification index.

كيفية قياس الطي القشرية من صور MR : برنامج تعليمي خطوة بخطوة لحساب الرقم القياسي المحلي Gyrification

Cortical folding (gyrification) is determined during the first months of life, so that adverse events occurring during this period leave traces that will ...

Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images

In this paper we present an automated system based mainly on the computed tomography (CT) images consisting of two main components: the midline shift estimation and intracranial pressure (ICP) pre-screening system. To estimate the midline shift, first an estimation of the ideal midline is performed based on the symmetry of the skull and anatomical features in the brain CT scan. Then, segmentation of the ventricles from the CT scan is performed and used as a guide for the identification of the actual midline through shape matching. These processes mimic the measuring process by physicians and have shown promising results in the evaluation. In the second component, more features are extracted related to ICP, such as the texture information, blood amount from CT scans and other recorded features, such as age, injury severity score to estimate the ICP are also incorporated. Machine learning techniques including feature selection and classification, such as Support Vector Machines (SVMs), are employed to build the prediction model using RapidMiner. The evaluation of the prediction shows potential usefulness of the model. The estimated ideal midline shift and predicted ICP levels may be used as a fast pre-screening step for physicians to make decisions, so as to recommend for or against invasive ICP monitoring.

An automated midline shift estimation and intracranial pressure (ICP) pre-screening system based on computed tomography (CT) images for patients with traumatic brain injury (TBI) is proposed using image processing and machine learning techniques.

خط الوسط التحول الآلي وتقدير الضغط داخل الجمجمة يعتمد على الصور CT الدماغ

In this paper we present an automated system based mainly on the computed tomography (CT) images consisting of two main components: the midline shift ...

Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which disrupt normal brain function. Despite treatment with currently available antiepileptic drugs targeting neuronal functions, one third of patients with epilepsy are pharmacoresistant. In this condition, surgical resection of the brain area generating seizures remains the only alternative treatment. Studying human epileptic tissues has contributed to understand new epileptogenic mechanisms during the last 10 years. Indeed, these tissues generate spontaneous interictal epileptic discharges as well as pharmacologically-induced ictal events which can be recorded with classical electrophysiology techniques. Remarkably, multi-electrode arrays (MEAs), which are microfabricated devices embedding an array of spatially arranged microelectrodes, provide the unique opportunity to simultaneously stimulate and record field potentials, as well as action potentials of multiple neurons from different areas of the tissue. Thus MEAs recordings offer an excellent approach to study the spatio-temporal patterns of spontaneous interictal and evoked seizure-like events and the mechanisms underlying seizure onset and propagation. Here we describe how to prepare human cortical slices from surgically resected tissue and to record with MEAs interictal and ictal-like events ex vivo.

We here describe how to perform multi-electrode array recordings of human epileptic cortical tissue. Epileptic tissue resection, slice preparation and multi-electrode array recordings of interictal and ictal events are demonstrated in detail.

متعدد القطب تسجيلات صفيف من داء الصرع بعد الجراحة القشرية الأنسجة البشرية

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which ...

A Thrombotic Stroke Model Based On Transient Cerebral Hypoxia-ischemia

Stroke research has endured many setbacks in translating neuroprotective therapies into clinical practice. In contrast, the real-world therapy (tPA thrombolysis) rarely produces benefits in mechanical occlusion-based experimental models, which dominate preclinical stroke research. This split between the bench and bedside suggests the need to employ tPA-responsive models in preclinical stroke research. To this end, a simple and tPA-reactive thrombotic stroke model is invented and described here. This model consists of transient occlusion of the unilateral common carotid artery and delivery of 7.5% oxygen through a face mask in adult mice for 30 min, while maintaining the animal rectal temperature at 37.5 &#177; 0.5 &#176;C. Although reversible ligation of the unilateral carotid artery or hypoxia each suppressed cerebral blood flow only transiently, the combination of both insults caused lasting reperfusion deficits, fibrin and platelet deposition, and large infarct in the middle cerebral artery-supplied territory. Importantly, tail-vein injection of recombinant tPA at 0.5, 1, or 4 hr post-tHI (10 mg/kg) provided time-dependent reduction of the mortality rate and infarct size. This new stroke model is simple and can be standardized across laboratories to compare experimental results. Further, it induces thrombosis without craniectomy or introducing pre-formed emboli. Given these unique merits, the tHI model is a useful addition to the repertoire of preclinical stroke research.

Thromboembolic stroke models are vital tools for optimizing the recanalization therapy. Here we report a murine thrombotic stroke model based on transient cerebral hypoxic-ischemic (tHI) insult, which triggers thrombosis and infarction, and responds favorably to tissue plasminogen activator (tPA)-mediated fibrinolysis in a therapeutic window similar to those in stroke patients.

A السكتة الدماغية نموذج الخثاري بناء على عابر الدماغي نقص الأكسجة-نقص التروية

Stroke research has endured many setbacks in translating neuroprotective therapies into clinical practice. In contrast, the real-world therapy (tPA ...

Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, obesity and diabetes. Accordingly, when evaluating therapies for stroke in animals, it is important to select a model with excellent face validity. Ischemic stroke accounts for 80% of all strokes, and the majority of these occur in the territory of the middle cerebral artery (MCA), often inducing infarcts that affect the sensorimotor cortex, causing persistent plegia or paresis on the contralateral side of the body. We demonstrate in this video a method for producing ischemic stroke in elderly rats, which causes sustained sensorimotor disability and substantial cortical infarcts. Specifically, we induce permanent distal middle cerebral artery occlusion (MCAO) in elderly female rats by using diathermy forceps to occlude a short segment of this artery. The carotid artery on the ipsilateral side to the lesion was then permanently occluded and the contralateral carotid artery was transiently occluded for 60 min. We measure the infarct size using structural T2-weighted magnetic resonance imaging (MRI) at 24 hr and 8 weeks after stroke. In this study, the mean infarct volume was 4.5% &#177; 2.0% (standard deviation) of the ipsilateral hemisphere at 24 hr (corrected for brain swelling using Gerriet&#8217;s equation, n = 5). This model is feasible and clinically relevant as it permits the induction of sustained sensorimotor deficits, which is important for the elucidation of pathophysiological mechanisms and novel treatments.

Here we present a protocol to produce permanent distal middle cerebral artery occlusion in elderly female rats with simultaneous occlusion of the carotid arteries to generate large cortical infarcts and sustained deficits. We show confirmation of the lesion size using structural MRI at 24 hr and 8 weeks after stroke.

أداء الدائم القاصي الأوسط الدماغي مع السباتي المشترك انسداد الشريان في الجرذان المسنين لدراسة القشرية نقص التروية ذوي الإعاقة المستديمة

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, ...

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts. The optical mapping system is assembled with dual high-speed complementary metal oxide semiconductor cameras and high magnification objective lenses, to detect the fluorescence of a voltage-sensitive dye and Ca2+ indicator. To focus on the assessment of murine atria, optical mapping is performed with an area of 2 mm &#215; 2 mm or 10 mm x 10 mm, with a 100 &#215; 100 resolution (20 &#181;m/pixel or 100 &#181;m/pixel) and sampling rate of up to 10 kHz (0.1 ms) at maximum. A 1-French size quadripolar electrode pacing catheter is placed into the right atrium through the superior vena cava avoiding any mechanical damage to the atrium, and pacing stimulation is delivered through the catheter. An electrophysiological study is performed with programmed stimulation including constant pacing, burst pacing, and up to triple extrastimuli pacing. Under a spontaneous or pacing rhythm, the optical mapping recorded the action potential duration, activation map, conduction velocity, and Ca2+ transient individually in the right and left atria. In addition, the programmed stimulation also determines the inducibility of atrial tachyarrhythmias. Precise activation mapping is performed to identify the propagation of the excitation in the atrium during an induced atrial tachyarrhythmia. Optical mapping with a specialized setting enables a thorough electrophysiological evaluation of the atrium in murine pathological models.

This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter.

تقييم الكهربية من مورين الاذينين مع رسم الخرائط الضوئية عالية الدقة

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and ...

Assessing Neuroprotective Effects of Glycyrrhizae Radix et Rhizoma Extract Using a Transient Middle Cerebral Artery Occlusion Mouse Model

Ischemia followed by reperfusion of cerebral blood flow after a stroke leads to the death of nerve cells and loss of brain tissue. The most commonly used animal model for studying stroke is the middle cerebral artery occlusion (MCAO) model. Previous research studies have reported different infarct sizes even when the same experimental animal species was used under similar MCAO conditions. Therefore, we developed an improved experimental method to address this discrepancy. Mice were subjected to MCAO using a filament as the occlusion material to mimic human stroke conditions and filament thickness was optimized to establish more reproducible infarction volume. Mice treated with a methanol extract of Glycyrrhizae Radix et Rhizome (GRex) following stroke induction showed a significantly decreased total infarction volume and increased number of surviving cells relative to the untreated control group. This modified experimental protocol successfully and reproducibly demonstrated the beneficial effect of GRex on ischemic stroke.

In this study, we modify an existing experimental method to obtain more reproducible results, by establishing a middle cerebral artery occlusion (MCAO) mouse model. Oral administration of Glycyrrhizae Radix et Rhizome (GR) methanol extract (GRex), following stroke induction, significantly decreased total infarction volume relative to the untreated control group.

تقييم آثار محصن من الرقم الأساسي جليسيرهيزاي et ريزوما استخراج باستخدام نموذج ماوس انسداد شريان دماغي الأوسط عابر

Ischemia followed by reperfusion of cerebral blood flow after a stroke leads to the death of nerve cells and loss of brain tissue. The most commonly used ...

High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding cardiac function and metabolism. In preclinical research, dedicated scanners with high sensitivity and high spatio-temporal resolution are employed, designed to cope with the demanding technological requirements posed by the small heart size and very high heart rates of mice and rats. In this paper, a bimodal cardiac PET/CT imaging protocol for experimental mouse and/or rat models of cardiac diseases is described, from animal preparation and image acquisition and reconstruction to image processing and visualization.
In particular, the 18F-labeled fluorodeoxyglucose ([18F]FDG)-PET scan allows for the measurement and visualization of glucose metabolism in the different segments of the left ventricle (LV). Polar maps are convenient tools to display this information. The CT part consists of a time-resolved 3D reconstruction of the entire heart (4D-CT) using retrospective gating without electrocardiography (ECG) leads, allowing the morphofunctional evaluation of the LV and the subsequent quantification of the most important cardiac function parameters, such as ejection fraction (EF) and stroke volume (SV). Using an integrated PET/CT scanner, this protocol can be executed within the same anesthesia induction without the need to reposition the animal between different scanners. Hence, PET/CT can be seen as a comprehensive tool for the morphofunctional and metabolic evaluation of the heart in several small animal models of cardiac diseases.

Here, we present an experimental imaging protocol for the quantification of cardiac function and morphology using high-resolution positron emission tomography/computed tomography for small animals. Both mice and rats are considered, discussing the different requirements of computed tomography contrast agents for the two species.

التصوير المقطعي بالإصدار البوزيتروني القلبي عالي الدقة / التصوير المقطعي المحوسب للحيوانات الصغيرة

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding ...

تحديد التنفس في المنوية البشرية عن طريق قياس التنفس عالي الدقة

High-Resolution Respirometry to Assess Mitochondrial Function in Human Spermatozoa

Semen quality is often studied by routine semen analysis, which is descriptive and often inconclusive. Male infertility is associated with altered sperm mitochondrial activity, so the measurement of sperm mitochondrial function is an indicator of sperm quality. High-resolution respirometry is a method of measuring the oxygen consumption of cells or tissues in a closed-chamber system. This technique can be implemented to measure respiration in human sperm and provides information about the quality and integrity of the sperm mitochondria. High-resolution respirometry allows the cells to move freely, which is an a priori advantage in the case of sperm. This technique can be applied with intact or permeabilized spermatozoa and allows for the study of intact sperm mitochondrial function and the activity of individual respiratory chain complexes. The high-resolution oxygraph instrument uses sensors to measure the oxygen concentration coupled with sensitive software to calculate the oxygen consumption. The data are used to calculate respiratory indices based on the oxygen consumption ratios. Consequently, the indices are the proportions of two oxygen consumption rates and are internally normalized to the cell number or protein mass. The respiratory indices are an indicator of sperm mitochondrial function and dysfunction.

تسليط الضوء على المؤلف: تطوير أبحاث العقم عند الذكور عن طريق كشف استقلاب المنوية ووظيفة الميتوكوندريا 

The analysis of sperm mitochondrial function by high-resolution respirometry permits the measurement of the oxygen consumption of freely moving spermatozoa in a closed-chamber system. The technique can be applied to measure respiration in human spermatozoa, which provides information on sperm mitochondrial characteristics and integrity.

قياس التنفس عالي الدقة لتقييم وظيفة الميتوكوندريا في الحيوانات المنوية البشرية

Semen quality is often studied by routine semen analysis, which is descriptive and often inconclusive. Male infertility is associated with altered sperm ...