Name: continuous manual exchange transfusion for patients with sickle cell disease: an efficient method to avoid iron overload
Uploaded: 2017-03-14T14:00:00
Description: Watch this Scientific Journal Video about Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload at JoVE.com

We would like to thank the patients and parents for their continuous support; the caregivers for their dedication; Pr Bierling, director of the French Blood Bank in the Paris area, for his support of the collaborative work between our hospital and his team to develop the continuous manual exchange transfusion method; and the University Paris Diderot and the hospital Robert-Debr&#233; for their support.

The protocol follows the guidelines of the hospital ethics committee. There are 3 steps in the exchange sessions: patient preparation; initial isovolemic phlebotomy (if appropriate); and whole-blood exchange, consisting of several cycles, or continuous whole-blood phlebotomy, which is associated with the infusion of diluted PRBCs. Depending of the Hb level of the patient, a fourth step of intermediary isovolemic phlebotomy can be added midway through the exchange stage. At the start of the session, all of the necessary m...

<ol>
	<li>Stuart, M. J., Nagel, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sickle-cell+disease.">Sickle-cell disease.</a> Lancet. 364 (9442), 1343-1360 (2004).</li><li>Aygun, B., 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=Chronic+transfusion+practices+for+prevention+of+primary+stroke+in+children+with+sickle+cell+anemia+and+abnormal+TCD+velocities.">Chronic transfusion practices for prevention of primary stroke in children with sickle cell anemia and abnormal TCD velocities.</a> Am J Hematol. 87 (4), 428-430 (2012).</li><li>Ohene-Frempong, K., 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=Cerebrovascular+accidents+in+sickle+cell+disease:+rates+and+risk+factors.">Cerebrovascular accidents in sickle cell disease: rates and risk factors.</a> Blood. 91 (1), 288-294 (1998).</li><li>Adams, R. 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=Prevention+of+a+first+stroke+by+transfusions+in+children+with+sickle+cell+anemia+and+abnormal+results+on+transcranial+Doppler+ultrasonography.">Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography.</a> N Engl J Med. 339 (1), 5-11 (1998).</li><li>Scothorn, D. 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=Risk+of+recurrent+stroke+in+children+with+sickle+cell+disease+receiving+blood+transfusion+therapy+for+at+least+five+years+after+initial+stroke.">Risk of recurrent stroke in children with sickle cell disease receiving blood transfusion therapy for at least five years after initial stroke.</a> J Pediatr. 140 (3), 348-354 (2002).</li><li>Koehl, B., 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=Comparison+of+automated+erythrocytapheresis+versus+manual+exchange+transfusion+to+treat+cerebral+macrovasculopathy+in+sickle+cell+anemia.">Comparison of automated erythrocytapheresis versus manual exchange transfusion to treat cerebral macrovasculopathy in sickle cell anemia.</a> Transfusion. 56 (5), 1121-1128 (2016).</li><li>Kim, H. C., 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=Erythrocytapheresis+therapy+to+reduce+iron+overload+in+chronically+transfused+patients+with+sickle+cell+disease.">Erythrocytapheresis therapy to reduce iron overload in chronically transfused patients with sickle cell disease.</a> Blood. 83 (4), 1136-1142 (1994).</li><li>Adamkiewicz, T. V., 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=Serum+ferritin+level+changes+in+children+with+sickle+cell+disease+on+chronic+blood+transfusion+are+nonlinear+and+are+associated+with+iron+load+and+liver+injury.">Serum ferritin level changes in children with sickle cell disease on chronic blood transfusion are nonlinear and are associated with iron load and liver injury.</a> Blood. 114 (21), 4632-4638 (2009).</li><li>Raghupathy, R., Manwani, D., Little, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Iron+overload+in+sickle+cell+disease.">Iron overload in sickle cell disease.</a> Adv Hematol. , (2010).</li><li>Porter, J. B., Evangeli, M., El-Beshlawy, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Challenges+of+adherence+and+persistence+with+iron+chelation+therapy.">Challenges of adherence and persistence with iron chelation therapy.</a> Int J Hematol. 94 (5), 453-460 (2011).</li></ol>

The risk associated with this procedure is an unexpected misbalance between the phlebotomy and the transfusion, which can have dangerous consequences. A rapid depletion will lead to hypovolemia and acute anemia, while an excess transfusion without bleeding will lead to a dangerous increase in blood viscosity. In both cases, SCA patients could suffer from vaso-occlusive complications, as well as strokes. For this reason, one nurse must be dedicated to each patient and stay at his bedside during the whole procedure. There ...

A single point mutation in the &#946;-globin gene is responsible for the production of abnormal hemoglobin (hemoglobin S, HbS). This causes sickle cell anemia (SCA), one of the most common diseases worldwide1. SCA patients&#39; acute symptoms and some chronic complications can be treated by the transfusion of packed red blood cells (PRBCs). Indeed, the transfusion of normal RBCs corrects the anemia while diluting the sickle RBCs. As a result, it can increase the oxygen transport capacity while decreasing hemolysis and vaso-occlusive events. To avoid chronic complications or to treat patients with acute complications, transfusion combined with the depletion of sickle RBCs, either by phlebotomy or by erythrapheresis, is an effective way to limit the dangerous increase in hemoglobin and blood viscosity while reducing the number of circulating SS RBCs2.
One of the main causes of psychomotor handicaps and neurocognitive deficiencies in children with SCA3 is cerebral vasculopathy, a devastating complication of this disease. In SCA children with abnormally high velocities on transcranial Doppler, chronic transfusions are effective in preventing the occurrence of the first stroke4. To reduce the risk of recurrence in patients that have already suffered from an ischemic stroke, transfusion therapy is the most adequate method5. In the case of chronic therapy, RBC exchange transfusion is better than simple RBC transfusion, as it removes sickle cells and adds normal cells while reducing blood viscosity and limiting iron overload. Nonetheless, simple RBC transfusion is still widely used as a treatment for cerebral macro-vasculopathy. While it rapidly leads to iron overload4, this choice is often made because it is technically simple and maximizes the number of patients in transfusion care. Indeed, even if erythrapheresis has been reported to be the most efficient method for the chronic transfusion of SCA patients, it cannot be implemented everywhere; it is not suitable for all patients, especially young children; and it necessitates specific and expensive equipment.
For more than 20 years now, we have been treating SCA children demonstrating cerebral vasculopathy and who were temporarily ineligible for erythrapheresis with a continuous manual exchange transfusion (MET) method. In 2016, our team published a follow-up of patients that had undergone continuous manual transfusion for several years, showing that our method is associated with a satisfactory HbS decrease, efficient stroke prevention, and a limitation of iron overload comparable to that of erythrapheresis6. A session of MET can be carried out in any hospital environment without specific apparatuses and by using the same volume needed for erythrapheresis. A notable advantage of this technique is that it could help prevent, or at least diminish, side effects (particularly iron overload) linked to repeated transfusions in patients who are not able to undergo erythrapheresis. The aim of this article is to describe, step by step, how to perform a session of continuous MET in order to allow the medical centers that do not have any apheresis machines, or that have patients who are not eligible for erythrapheresis, to use this method for their SCD patients, especially children.

<table border="0" cellpadding="0" cellspacing="0" width="569">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:195px;">Precision scale</td>
			<td style="width:100px;"></td>
			<td style="width:117px;"></td>
			<td style="width:159px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cannula (x2)</td>
			<td>Macopharma</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Transfusion tubing (x2)</td>
			<td>Macopharma</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bleeding bag (x4)</td>
			<td>Macopharma</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">3 Way tap</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Syringe (x4)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Hemoglobin test</td>
			<td>HemoCue</td>
			<td style="width:117px;">Hb 201+&#160;System</td>
			<td></td>
		</tr>
	</tbody>
</table>

continuous manual exchange transfusion for patients with sickle cell disease: an efficient method to avoid iron overload

Children with sickle cell anemia (SCA) may be at risk of cerebral vasculopathy and strokes, which can be prevented by chronic transfusion programs. Repeated transfusions of packed red blood cells (PRBCs) is currently the simplest and most used technique for chronic transfusion programs. However, iron overload is one of the major side effects of this therapy. More developed methods exist, notably the apheresis of RBC (erythrapheresis), which is currently the safest and most efficient method. However, it is costly, complicated, and cannot be implemented everywhere, nor is it suitable for all patients. Manual exchange transfusions combine one or more manual phlebotomies with a PRBC transfusion.
At the Reference Center of Sickle Cell Disease, we set up a continuous method of manual exchange transfusion that is feasible for all hospital settings, demands no specific equipment, and is widely applicable. In terms of HbS decrease, stroke prevention, and iron overload prevention, this method showed comparable efficiency to erythrapheresis. In cases where erythrapheresis is not available, this method can be a good alternative for patients and care centers.

Here, we will compare the safety, cost, and efficiency of the MET method with erythrapheresis6, which is the most effective method to decrease the percentage of HbS in SCD patients. To do so, we recorded 1,353 transfusion exchange sessions in the Reference Center of SCD, including 333 sessions of AET and 1,020 sessions of MET, all in SCD children suffering from cerebral vasculopathy and/or strokes. For patients, we chose MET in children with a body weight under 25 ...

Watch this Scientific Journal Video about Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload at JoVE.com

Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload

We have outlined a method of continuous manual exchange transfusion for the treatment of sickle cell disease in patients. This safe protocol was designed to effectively limit iron overload in patients in need of chronic transfusions and can be used extensively without any special equipment.

Children with sickle cell anemia (SCA) may be at risk of cerebral vasculopathy and strokes, which can be prevented by chronic transfusion programs. ...

The overall goal of this method for continuous manual exchange transfusion is to treat sickle cell diseased patients in need of chronic transfusions while limiting their iron overload without the use of special equipment. This method can help answer key questions in the field of sickle cell anemia, about how to safely and efficiently perform chronic exchange transfusions when electrophoresis is not available. The main advantage of this technique is that it can be performed without specific equipment, but still maintain a similar efficiency to electrophoresis.Visual demonstration of this method is critical and the continuous phlebotomy steps must be strictly controlled and supervised. Before beginning the exchange transfusion session, have a physician perform a thorough and complete physical examination of the patient, paying specific attention to the body temperature and the hemodynamic parameters and obtain a recent body weight. Install a peripheral venous line to one limb for the phlebotomy and a second venous line to the other limb for the albumin and packed red blood cells infusion.Then administer one gram of calcium per OS to prevent hypocalcemia due to the presence of a calcium chelating anticoagulant in the transfusion bags. After the results of the exams have been checked, obtain the initial phlebotomy volume using the table as a guide for determining the volume and rate of the acquisition. Program the infusion of the same volume of albumin solution in the syringe pump.Before beginning the initial phlebotomy, confirm that the appropriate volume of phenotypically-matched packed red blood cells is available at the blood bank for the exchange transfusion. Carefully confirm the compatibility of each delivered blood bag. Just prior to the exchange transfusion, place the patient in the supine position with the feet slightly raised and administer one liter of oxygen via a nasal cannula.If the patient's hemoglobin level is greater than 8.5 grams per deciliter, begin an initial isovolemic phlebotomy by infusing the 5%albumin solution. After 20 to 50 milliliters of albumin have been infused, unclamp the peripheral intravenous access connected to an empty bleeding bag located below the patient's bed and begin the phlebotomy at the same rate as the albumin infusion. Monitor the patient every five minutes during the initial isovolemic phlebotomy.If the blood flow is too low, raise the bed to increase the height difference between the arm and the bleeding bag and consequently the blood flow. As the blood is collected, weigh the bleeding bag on a precision scale to adapt the infusion flow in real time to compensate for the volume of blood. At the end of the phlebotomy, use a hemoglobin point of care test to check the hemoglobin levels according to the manufacturer's instructions to confirm that the hemoglobin is around eight grams per deciliter.For the isovolemic exchange transfusion, begin by transfusing the first 20 milliliters of diluted packed red blood cells before starting the phlebotomy at the same rate of infusion. Monitor the patient every 15 minutes. If the hemoglobin level is higher than 9.5 grams per deciliter, perform an additional phlebotomy compensated by an infusion of the same volume of albumin solution.At the end of the exchange transfusion, perform the appropriate laboratory tests for determining hemoglobin, hemoglobin S, and calcium levels. Then administer one more gram of calcium per OS, keeping the patient under surveillance for at least one hour after the end of the exchange. As expected, in this representative experiment, the pediatric patients who received electrophoresis only exhibited a very stable ferritinemia.By comparison, the iron overload generated by a program of chronic red blood cell transfusions was approximately four times greater than that observed under the erythropheresis program. If only patients who received the manual exchange transfusion by the continuous method are considered, a quite stable ferritinemia with an almost equivalent control of iron overload as with erythropheresis is observed. After watching this video, you should have a good understanding of how to perform continuous manual exchange transfusion as a safe and effective alternative for sickle cell patients who need chronic transfusions.

continuous-manual-exchange-transfusion-for-patients-with-sickle-cell

Research

JoVE Journal

Medicine

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge.1-6 Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. 7, 8 
This video demonstrates a protocol for MMT, which has been taught to &ge;43 research staff who have performed &gt;800 assessments on &gt;280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale.7,9-11 Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. 1,2.

Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, ...

Labeling Stem Cells with Ferumoxytol, an FDA-Approved Iron Oxide Nanoparticle

Stem cell based therapies offer significant potential for the field of regenerative medicine. However, much remains to be understood regarding the in vivo kinetics of transplanted cells. A non-invasive method to repetitively monitor transplanted stem cells in vivo would allow investigators to directly monitor stem cell transplants and identify successful or unsuccessful engraftment outcomes.
A wide range of stem cells continues to be investigated for countless applications. This protocol focuses on 3 different stem cell populations: human embryonic kidney 293 (HEK293) cells, human mesenchymal stem cells (hMSC) and induced pluripotent stem (iPS) cells. HEK 293 cells are derived from human embryonic kidney cells grown in culture with sheared adenovirus 5 DNA. These cells are widely used in research because they are easily cultured, grow quickly and are easily transfected. hMSCs are found in adult marrow. These cells can be replicated as undifferentiated cells while maintaining multipotency or the potential to differentiate into a limited number of cell fates. hMSCs can differentiate to lineages of mesenchymal tissues, including osteoblasts, adipocytes, chondrocytes, tendon, muscle, and marrow stroma. iPS cells are genetically reprogrammed adult cells that have been modified to express genes and factors similar to defining properties of embryonic stem cells. These cells are pluripotent meaning they have the capacity to differentiate into all cell lineages 1. Both hMSCs and iPS cells have demonstrated tissue regenerative capacity in-vivo.
Magnetic resonance (MR) imaging together with the use of superparamagnetic iron oxide (SPIO) nanoparticle cell labels have proven effective for in vivo tracking of stem cells due to the near microscopic anatomical resolution, a longer blood half-life that permits longitudinal imaging and the high sensitivity for cell detection provided by MR imaging of SPIO nanoparticles 2-4. In addition, MR imaging with the use of SPIOs is clinically translatable. SPIOs are composed of an iron oxide core with a dextran, carboxydextran or starch surface coat that serves to contain the bioreactive iron core from plasma components. These agents create local magnetic field inhomogeneities that lead to a decreased signal on T2-weighted MR images 5. Unfortunately, SPIOs are no longer being manufactured. Second generation, ultrasmall SPIOs (USPIO), however, offer a viable alternative. Ferumoxytol (FerahemeTM) is one USPIO composed of a non-stoichiometric magnetite core surrounded by a polyglucose sorbitol carboxymethylether coat. The colloidal, particle size of ferumoxytol is 17-30 nm as determined by light scattering. The molecular weight is 750 kDa, and the relaxivity constant at 2T MRI field is 58.609 mM-1 sec-1 strength4. Ferumoxytol was recently FDA-approved as an iron supplement for treatment of iron deficiency in patients with renal failure 6. Our group has applied this agent in an &ldquo;off label&rdquo; use for cell labeling applications. Our technique demonstrates efficient labeling of stem cells with ferumoxytol that leads to significant MR signal effects of labeled cells on MR images. This technique may be applied for non-invasive monitoring of stem cell therapies in pre-clinical and clinical settings.

We describe a technique for labeling and tracking stem cells with FDA-approved, superparamagnetic iron oxide (SPIO), ferumoxytol (Feraheme). This cellular imaging technique that utilizes magnetic resonance (MR) imaging for visualization, is readily accessible for long-term monitoring and diagnosis of successful or unsuccessful stem cell engraftments in patients.

Stem cell based therapies offer significant potential for the field of regenerative medicine. However, much remains to be understood regarding the in vivo ...

Preparation and Pathogen Inactivation of Double Dose Buffy Coat Platelet Products using the INTERCEPT Blood System

Blood centers are faced with many challenges including maximizing production yield from the blood product donations they receive as well as ensuring the highest possible level of safety for transfusion patients, including protection from transfusion transmitted diseases. This must be accomplished in a fiscally responsible manner which minimizes operating expenses including consumables, equipment, waste, and personnel costs, among others.
Several methods are available to produce platelet concentrates for transfusion. One of the most common is the buffy coat method in which a single therapeutic platelet unit (&ge; 2.0 x1011 platelets per unit or per local regulations) is prepared by pooling the buffy coat layer from up to six whole blood donations. A procedure for producing "double dose" whole blood derived platelets has only recently been developed.
Presented here is a novel method for preparing double dose whole blood derived platelet concentrates from pools of 7 buffy coats and subsequently treating the double dose units with the INTERCEPT Blood System for pathogen inactivation. INTERCEPT was developed to inactivate viruses, bacteria, parasites, and contaminating donor white cells which may be present in donated blood. Pairing INTERCEPT with the double dose buffy coat method by utilizing the INTERCEPT Processing Set with Dual Storage Containers (the "DS set"), allows blood centers to treat each of their double dose units in a single pathogen inactivation processing set, thereby maximizing patient safety while minimizing costs. The double dose buffy coat method requires fewer buffy coats and reduces the use of consumables by up to 50% (e.g. pooling sets, filter sets, platelet additive solution, and sterile connection wafers) compared to preparation and treatment of single dose buffy coat platelet units. Other cost savings include less waste, less equipment maintenance, lower power requirements, reduced personnel time, and lower collection cost compared to the apheresis technique.

This article describes the process used by &#214;rebro University Hospital to produce double dose buffy coat platelet concentrates prepared from whole blood donations and treated with the INTERCEPT Blood System for pathogen inactivation. The in vitro quality of the final platelet units are evaluated over 7 days of storage.

Blood centers are faced with many challenges including maximizing production yield from the blood product donations they receive as well as ensuring the ...

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur).
There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized.
Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment.
Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study.
Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patient's entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.

Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia.

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture ...

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50&#8211;60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage.

We describe a stepwise procedure for creating pressure overload and left ventricular hypertrophy in Wistar rats by constriction of the ascending aorta using a small metallic clip. This model is extensively used for studying remodeling changes during cardiac hypertrophy and for identifying and evaluating strategies for regression of such changes.

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart ...

Assessment of Vascular Function in Patients With Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this is only partially explained by traditional CVD risk factors. Vascular dysfunction is an important non-traditional risk factor, characterized by vascular endothelial dysfunction (most commonly assessed as impaired endothelium-dependent dilation [EDD]) and stiffening of the large elastic arteries. While various techniques exist to assess EDD and large elastic artery stiffness, the most commonly used are brachial artery flow-mediated dilation (FMDBA) and aortic pulse-wave velocity (aPWV), respectively. Both of these noninvasive measures of vascular dysfunction are independent predictors of future cardiovascular events in patients with and without kidney disease. Patients with CKD demonstrate both impaired FMDBA, and increased aPWV. While the exact mechanisms by which vascular dysfunction develops in CKD are incompletely understood, increased oxidative stress and a subsequent reduction in nitric oxide (NO) bioavailability are important contributors. Cellular changes in oxidative stress can be assessed by collecting vascular endothelial cells from the antecubital vein and measuring protein expression of markers of oxidative stress using immunofluorescence. We provide here a discussion of these methods to measure FMDBA, aPWV, and vascular endothelial cell protein expression.

The degree of vascular dysfunction and contributing physiological mechanisms can be assessed in patients with chronic kidney disease by measuring brachial artery flow-mediated dilation, aortic pulse-wave velocity, and vascular endothelial cell protein expression.

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this ...

Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites

It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites.

The most studied aspect of the biocompatibility of dental composites is their cytotoxicity 3D CLSM time lapse imaging combined with fluorescent signal quantification allows sensitive evaluation of the cell fate over time. Utilizing this method could be an efficient tool to assess the cytocompatibility of dental composites.

It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The ...

Cutaneous Surgical Denervation:  A Method for Testing the Requirement for Nerves in Mouse Models of Skin Disease

Cutaneous somatosensory nerves function to detect diverse stimuli that act upon the skin. In addition to their established sensory roles, recent studies have suggested that nerves may also modulate skin disorders including atopic dermatitis, psoriasis and cancer. Here, we describe protocols for testing the requirement for nerves in maintaining a cutaneous mechanosensory organ, the touch dome (TD). Specifically, we discuss methods for genetically labeling, harvesting and visualizing TDs by whole-mount staining, and for performing unilateral surgical denervation on mouse dorsal back skin. Together, these approaches can be used to directly compare TD morphology and gene expression in denervated as well as sham-operated skin from the same animal. These methods can also be readily adapted to examine the requirement for nerves in mouse models of skin pathology. Finally, the ability to repeatedly sample the skin provides an opportunity to monitor disease progression at different stages and times after initiation.

This article includes detailed protocols for genetic labeling of mouse skin, surgical denervation, skin biopsy and visualizing labeled epithelia by whole-mount &#946;-galactosidase staining. These methods can be used to test the requirement for nerves in mouse models of normal and pathological skin.

Cutaneous somatosensory nerves function to detect diverse stimuli that act upon the skin. In addition to their established sensory roles, recent studies ...

Rapid and Efficient Generation of Recombinant Human Pluripotent Stem Cells by Recombinase-mediated Cassette Exchange in the AAVS1 Locus

Even with the revolution of gene-targeting technologies led by CRISPR-Cas9, genetic modification of human pluripotent stem cells&#160;(hPSCs)&#160;is still time consuming. Comparative studies that use recombinant lines with transgenes integrated into safe harbor loci could benefit from approaches that use site-specific targeted recombinases, like Cre or FLPe, which are more rapid and less prone to off-target effects. Such methods have been described, although they do not significantly outperform gene targeting in most aspects. Using Zinc-finger nucleases, we previously created a master cell line in the AAVS1 locus of hPSCs&#160;that contains a GFP-Hygromycin-tk expressing cassette, flanked by heterotypic FRT sequences. Here, we describe the procedures to perform FLPe recombinase-mediated cassette exchange (RMCE) using this line. The master cell line is transfected with a RMCE donor vector, which contains a promoterless Puromycin resistance, and with FLPe recombinase. Application of both a positive (Puromycin) and negative (FIAU) selection program leads to the selection of RMCE without random integrations. RMCE generates fully characterized pluripotent polyclonal transgenic lines in 15 d&#160;with 100% efficiency. Despite the recently described limitations of the AAVS1 locus, the ease of the system paves the way for hPSC transgenesis in isogenic settings, is necessary for comparative studies, and enables semi-high-throughput genetic screens for gain/loss of function analysis that would otherwise be highly time consuming.

Rapid and Efficient Generation of Recombinant Human Pluripotent Stem Cells by Recombinase-mediated Cassette Exchange in the AAVS1 Locus

Here we report a rapid and efficient gene editing method based on RMCE in the AAVS1 locus of human Pluripotent Stem Cells (hPSCs) that improves upon previously described systems. Using this technique, isogenic lines can be rapidly and reliably generated for proper comparative studies, facilitating transgenesis-mediated research with hPSCs.

Even with the revolution of gene-targeting technologies led by CRISPR-Cas9, genetic modification of human pluripotent stem cells&#160;(hPSCs)&#160;is ...

An Efficient Sieving Method to Isolate Intact Glomeruli from Adult Rat Kidney

Preservation of glomerular structure and function is pivotal in the prevention of glomerulonephritis, a category of kidney disease characterized by proteinuria which can eventually lead to chronic and end-stage renal disease. The glomerulus is a complex apparatus responsible for the filtration of plasma from the body. In disease, structural integrity is lost and allows for the abnormal leakage of plasma contents into the urine. A method to isolate and examine glomeruli in culture is critical for the study of these diseases. In this protocol, an efficient method of retrieving intact glomeruli from adult rat kidneys while conserving structural and morphological characteristics is described. This process is capable of generating high yields of glomeruli per kidney with minimal contamination from other nephron segments. With these glomeruli, injury conditions can be mimicked by incubating them with a variety of chemical toxins, including protamine sulfate, which causes foot process effacement and proteinuria in animal models. Degree of injury can be assessed using transmission electron microscopy, immunofluorescence staining, and western blotting. Nephrin and Wilms Tumor 1 (WT1) levels can also be assessed from these cultures. Due to the ease and flexibility of this protocol, the isolated glomeruli can be utilized as described or in a way that best suits the needs of the researcher to help better study glomerular health and structure in diseased states.

The main focus of this protocol is to efficiently isolate viable primary glomeruli cultures with minimal contaminants for use in a variety of downstream applications. The isolated glomeruli retain structural relationships between component cell types and can be cultured ex vivo for a short time.

Preservation of glomerular structure and function is pivotal in the prevention of glomerulonephritis, a category of kidney disease characterized by ...