Los autores reconocen el apoyo financiero de la Fundación Nacional de Ciencia (NSF) concede CEE-0.540.832 titulada &quot;Tecnologías del Medio infrarrojos para la Salud y el Medio Ambiente (MIRTHE)&quot;

1. Preparación de Instrumentos <ol><li> Encienda la fuente de alimentación externa a la plataforma de sensor óptico amoníaco, controlador de láser de diodo, una unidad electrónica de control a la medida (CEU), el muestreador de aire, bomba de aire, y un ordenador portátil. </li><li> Compruebe que tanto el tubo de escape y ventiladores de refrigeración del sensor de amoniaco están operando. NOTA: Se encuentra situada en la parte posterior del sensor, el segundo se encuentra dentro del sensor, que es fácilmente accesible. </li><li> Asegúrese de que el módulo de detección acústica y temperatura de la válvula de aguja están en 38,0 ° C mediante la comprobación de la pantalla digital situada en el lado de la caja de sensor de amoniaco. Espere unos 35 minutos desde el momento en que el sensor se suministra energía para que la temperatura se estabilice. </li><li> Establecer tubo de entrada y la temperatura de la boquilla a 55 ° C haciendo clic en un icono de nombre &quot;ChangeT&quot; que se encuentra en el escritorio del muestreador aliento. La temperatura puede ser cambiado haciendo clic en la flecha arriba o abajo seguido haciendo clic en &quot;Actucomió Temp &quot;. Haga clic en &quot;Exit&quot; para volver al escritorio. Deje que el sistema por lo menos 5 minutos para que la temperatura se estabilice. El mantenimiento de la temperatura de la toma de muestras y el tubo a 55 º C reduce al mínimo la pérdida de superficie de amoniaco. </li><li> Abra el software en la computadora portátil que controla el sensor de amoníaco. El programa se puede acceder dentro de una carpeta llamada &quot;NH 3 Programa Sensor Breath&quot; en el escritorio. Dentro de esta carpeta, el usuario debe seleccionar el icono de &quot;software principal labview&quot;. Esta carpeta contiene varias aplicaciones, pero el usuario debe seleccionar &quot;Mainsequence.vi&quot; para acceder a la interfaz deseada. Seleccione &quot;Ejecutar&quot; en la esquina superior izquierda de la pantalla. NOTA: Esto comienza la línea de bloqueo de secuencia de calibración. El láser del monitor QEPAS opera en una corriente óptima, que se selecciona durante un procedimiento de línea de bloqueo automático. Este proceso tendrá una duración aproximada de 25 min. </li><li> Crear una nueva sesión en la toma de muestras de tal manera que easesión sujeto ch tiene su propio archivo que se guarda en una memoria adjunta. NOTA: Esto se realiza mediante la apertura del programa &quot;Sampler Aliento&quot; que se encuentra en el escritorio del sampler. Hay espacio para identificar la sesión apropiadamente. Todos los datos generados durante la sesión se guardarán en la unidad flash en virtud de este identificador. La fecha del experimento se utiliza típicamente como parte del nombre de archivo. La entrada y la temperatura de la boquilla se deben ajustar antes de entrar en el programa de la respiración de muestreo. </li><li> Inserte una nueva boquilla desechable en la tubería de entrada. Use guantes desechables para evitar la contaminación de boquilla con el amoníaco de los dedos. </li></ol> 2. Respiración Sample Collection NOTA: La Junta de Revisión Institucional correspondiente (Consejo de Ética) debe aprobar cualquier estudio que involucra sujetos humanos. Hay muchos factores que pueden influir drásticamente aliento amoníaco. Estos factores pueden alterar las mediciones de amoniaco por el aliento directamente unffecting niveles de amoníaco sistémicos o afectando el viaje de los metabolitos de respiración de los pulmones a la instrumentación. <ol><li> Asegúrese sujetos llegan al laboratorio en ayunas, después de haber consumido ningún alimento durante aproximadamente 12 horas a la llegada y que se han abstenido de ejercicio por la mañana antes de la prueba. </li><li> Asegúrese de ninguna sustancia ha sido introducida en la boca por lo menos 1 hora antes de la recogida de datos. Asegúrese de que los sujetos se cepillan los dientes superior a 1 hora antes de la prueba. </li><li> Asiente el sujeto delante del sensor de amoníaco. Instruya al sujeto que mantenga la tubería de entrada y asegúrese de que no se toquen la boquilla para evitar la contaminación de amoníaco. </li><li> Haga clic en &quot;Inicio&quot; en la interfaz de sampler. Haga que el sujeto exhala en la boquilla durante el tiempo que pueden, o hasta que el operador considere que la muestra es suficiente. NOTA: Se trata de una sola exhalación completa de al menos 10 segundos. Presión en la boca se mide en tiempo real como un sustitutopara la tasa de flujo. Un medidor de presión de un código de colores ayuda a que el producto sujeto y mantener la presión de espiración deseado de 10 cm de agua, lo que representa una tasa de flujo de exhalación de 50 ml / seg. Se seleccionó este caudal, ya que ha sido adoptado por la ATS / ERS para el protocolo para determinar Fe NO. Este caudal de exhalación es alcanzable por los niños y adultos. Del mismo modo tres exhalaciones reproducibles deben obtenerse que difieren en menos de 10%. </li><li> Haga clic en &quot;Stop&quot; en la interfaz de sampler cuando se completa la muestra de aliento. </li></ol> 3. Aliento medición de la muestra <ol><li> Una vez que una muestra de aliento se ha analizado, el técnico de laboratorio de utilizar el monitor a continuación, tiene la capacidad de analizar cualquier segmento de que el perfil de la respiración. La porción de la respiración que es de interés es el segmento de la fase III. Este se caracteriza por una &quot;meseta&quot; en la concentración de dióxido de carbono y se encuentra en el centro para la etapa tardía de la BREath. </li><li> Seleccione la parte de fase III de la muestra arrastrando las líneas verticales en la interfaz de sampler para comenzar cuando mesetas de dióxido de carbono y detener justo antes de la caída de presión del aire. Consulte la Figura 1 para una aclaración. </li><li> Guarde los datos en la unidad flash haciendo clic en &quot;Guardar&quot; en la interfaz de pantalla táctil sampler. </li><li> Una vez que los datos se han almacenado de aliento, el usuario puede seleccionar en &quot;Inicio&quot; para iniciar una nueva muestra de aliento. </li></ol> 4. Ilustra los efectos de Enjuague Bucal y pH en amoníaco Breath <ol><li> Muestra 3 respiraciones para establecer el nivel de amoníaco de línea de base. Asegúrese de que las respiraciones se toman al menos 5 minutos el uno del otro. </li><li> Enjuagar bien la boca con una alícuota de 30 ml de agua durante 60 segundos. </li><li> Se recoge una muestra de aliento dentro de 60 segundos del enjuague (Sección 2). Recoger muestras de aliento en el transcurso de la siguiente hora para observar el cambio en amoniaco con el tiempo. NOTA: Samplos se puede tomar tan frecuentemente como cada minuto, pero intervalos más largos se utilizan típicamente. </li><li> Enjuagar bien la boca con una alícuota de 30 ml de la solución básica (bicarbonato de sodio en agua) durante 60 segundos y repita 4.2.1. </li><li> Enjuagar bien la boca con una alícuota de 30 ml de solución ácida durante 60 segundos y repita 4.2.1. </li></ol> 5. Ilustra los efectos de las temperaturas de entrada y de transporte de tubos de amoníaco Breath <ol><li> Ejemplos de tres respiraciones en el transcurso de 15 min con la temperatura de entrada fijada por debajo de la temperatura corporal, aproximadamente 30 ° C. </li><li> Aumente la temperatura de entrada y la tubería de transporte a 55 ° C, respectivamente, utilizando un icono de escritorio en la interfaz de pantalla táctil del muestreador aliento. Deje que el sistema por lo menos 5 minutos para alcanzar el estado de equilibrio. </li><li> Muestra 3 respiraciones, 5 min aparte en la entrada climatizada. </li></ol>

<ol>
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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+ammonia+in+biological+fluids.">Determination of ammonia in biological fluids.</a> Annals of clinical biochemistry. 31 (Pt 6), 529-543 (1994).</li><li>Lewicki, R., 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=Real+time+ammonia+detection+in+exhaled+human+breath+with+a+quantum+cascade+laser+based+sensor.">Real time ammonia detection in exhaled human breath with a quantum cascade laser based sensor.</a> 2009 Conference on Lasers and ElectroOptics and 2009 Conference on Quantum electronics and Laser Science Conference. 1, (2009).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+Thoracic+Society.+European+Respiratory+Society.+Recommendations+for+Standardized+Procedures+for+the+Online+and+Offline+Measurement+of+Exhaled+Lower+Respiratory+Nitric+Oxide+and+Nasal+Nitric+Oxide.">American Thoracic Society. 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Dr. Risby serves as a consultant for Loccioni Humancare the manufacturer of the breath sampler.

Los beneficios de un procedimiento no invasivo capaz de detectar metabolitos traza en tiempo real son obvias. Sin embargo, el campo de la investigación aliento ha tenido problemas para cumplir con este potencial. La medición de la respiración es un proceso dinámico vulnerable a muchos factores de confusión. Nuestro enfoque tiene ventajas importantes: en concreto, la sensibilidad y la velocidad del monitor amoniaco basado Arroz QEPAS junto al muestreador aliento nos han permitido evaluar e identificar los factores d...

El amoníaco es un subproducto ubicua de metabolismo de las proteínas 1. Medición de amoniaco, por lo tanto puede ayudar a los médicos a evaluar diversas enfermedades y estados de bienestar 2. Sin embargo, el amoniaco es difícil de medir con precisión, a través de la sangre o el aliento, debido a que es muy reactivo. Aunque se usa comúnmente, ensayos en sangre tienen numerosos inconvenientes, incluyendo preocupaciones básicas acerca de la precisión 3. Pero el principal problema con los ensayos de sangre es la realidad de que sólo alguna vez recogidos episódicamente. Esto es importante porque la fisiología de amoníaco, al igual que la glucosa en sangre y muchos otros procesos metabólicos, son fluidos y siempre cambiante 4. Por el contrario, los ensayos de respiración son totalmente no invasiva y rápida, lo que permite fácilmente medidas repetidas. Por lo tanto, la medición de amoniaco respiración es atractivo porque puede abordar una necesidad no cubierta de una manera única. Colección aliento, sin embargo, presenta problemas únicos. Mientras que la flebotomía lleva inherente la JeoPardy de error en varias maneras impredecibles (por ejemplo, tiempo de torniquete, la contaminación sudor, hemólisis de glóbulos, retardo en la medición de laboratorio, etc 5), los investigadores de medición de la respiración debe enfrentarse a un grupo diferente de nuevos desafíos: la variabilidad en la respiración, con la contaminación de mucosa oral o amoníaco bacteriana, la influencia de la humedad del aire y el aparato y temperatura ambiente, etc 6. De hecho, no es prudente subestimar la tarea en la conexión de equipo experimental para los seres humanos utilizando procedimientos experimentales para descubrir la biología desconocido. En parte debido a estos obstáculos, respirar amoníaco aún no ha alcanzado su potencial. Aquí, presentamos nuestro protocolo de medición de amoniaco aliento para obtener resultados rápidos y precisos. Nuestro protocolo tiene fuerza en tres áreas: el monitor, el sampler de la interfaz, y la atención a las influencias humanas. El monitor fue construido por colegas en la Universidad de Rice a lo descrito previamente 7. La base de la MEAsurement es un cuarzo mejorada espectroscopia fotoacústica técnica (QEPAS) que emplea un tenedor de sintonía piezoeléctrico de cuarzo como un transductor acústico. Fotoacústica efecto se produce cuando las ondas acústicas son producidos por la absorción de la radiación láser modulado por especies de gases traza objetivo. El gas de traza se detectó utilizando una célula acústica que es acústicamente resonante a la frecuencia modulada. Longitud de onda de la absorción del amoníaco fue seleccionado que esté libre de interferencia espectral interfieran especies en el aliento. Para los propósitos de la medición aliento exhalado humana, las principales características de la pantalla incluyen una amplia gama de medición (de ~ 50 partes por mil millones, ppb a 5000 ppb al menos) y la velocidad (1 mediciones sec). La velocidad del monitor permite la resolución de tiempo durante todo el ciclo de respiración. El monitor está acoplado a un muestreador de aire especialmente diseñado. La toma de muestras consiste en un sensor de presión y capnógrafo. Muestra y archivos en tiempo realmediciones de presión en la boca y dióxido de carbono, así como las concentraciones de amoníaco determinado por el sensor. Esta toma de muestras, por lo tanto, permite al técnico para evaluar la calidad del esfuerzo de respiración cuando se recoge la respiración. Esto nos permite exceder las recomendaciones para el análisis de aliento de óxido nítrico (FE NO), propuesto por el grupo operativo de la American Thoracic Society / European Respiratory Society (ATS / ERS) 8. Para todos muestras del aliento, se utilizó una válvula de una vía disponible en línea en el puerto de la boca de la toma de muestras aliento. Debido a la velocidad del monitor y los controles de calidad proporcionada por el sampler, hemos sido capaces de evaluar cuidadosamente las influencias humanas 9. La mayoría de los temas, por ejemplo, en un principio hiperventilar cuando se le indique para respirar. Otras influencias importantes, tales como el pH oral y enjuagues bucales, las temperaturas de la toma de muestras, el monitor y todos los tubos asociados, y el modo de respirar, se estudiaron a continuación, y son la base for los experimentos ilustrativos siguientes. Por último, y quizás lo más importante, hay que destacar que varios grupos altamente experimentados están midiendo el aliento amoníaco utilizando completamente diferentes sensores de medición y procedimientos. Estos pueden tener ventajas y validez importantes. Una comparación completa está más allá del alcance de la presente 10,11,12 trabajo.

<table border="0" cellpadding="0" cellspacing="0" width="666">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Rice Ammonia Monitor System</td>
			<td style="width:171px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Not available for commercial purchase</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Loccioni Breath Sampler</td>
			<td style="width:171px;">Loccioni Humancare</td>
			<td style="width:119px;">N/A</td>
			<td>Single breath version</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Disposable Mouth Piece</td>
			<td style="width:171px;">WestPrime Healthcare</td>
			<td style="width:119px;">G011-200</td>
			<td>Manufacturer is AlcoQuant</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Laptop</td>
			<td style="width:171px;">Lenovo</td>
			<td style="width:119px;">N/A</td>
			<td>Old model no longer sold by manufacturer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Acid Rinse</td>
			<td style="width:171px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td>Household acidic drink (coffee, soft drink, citrus juices, etc)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Base Rinse</td>
			<td style="width:171px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td>Water mixed with a nonexact amount of sodium bicarbonate (Arm &#38; Hammer Baking Soda)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Neutral Rinse</td>
			<td style="width:171px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td>Water</td>
		</tr>
	</tbody>
</table>

fast and accurate exhaled breath ammonia measurement

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. 
Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. 
The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations.

Los sujetos se pueden esperar para producir una amplia gama de niveles de amoniaco de respiración de línea de base. Las personas sanas pueden comenzar el día con una medición de amoniaco aliento de 100-1.000 ppb. Enjuagar la boca con el líquido cambia de inmediato la cantidad de aire amoníaco detectable. Fluidos neutros y ácidos típicamente cortan la cantidad de amoníaco observable por más de la mitad. Estos niveles luego regresan a la línea de base como los efectos de la enjuague desaparece. Los efectos del ...

Watch this Scientific Journal Video about Fast and Accurate Exhaled Breath Ammonia Measurement at JoVE.com

Fast and Accurate Exhaled Breath Ammonia Measurement

Ammonia is an important physiologic metabolite relevant to various disease and wellness states. It is also a difficult molecule to measure in breath, which demands particular precautions be taken to obtain accurate results. Not all factors influencing ammonia are known, but progress can be difficult without accounting for these factors.

Rápido y preciso exhalado Amoníaco Medición

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that ...

fast-and-accurate-exhaled-breath-ammonia-measurement

Research

JoVE Journal

Medicine

13.1K vistas.  St. Luke's University Hospital. Ammonia is an important physiologic metabolite relevant to various disease and wellness states. It is also a difficult molecule to measure in breath, which demands particular precautions be taken to obtain accurate results. Not all factors influencing ammonia are known, but progress can be difficult without accounting for these factors.

Video: Fast and Accurate Exhaled Breath Ammonia Measurement

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&beta; using a Whole Blood Stimulation Assay

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues as well as altered cytokine homeostasis. The innate immune system plays a crucial role in recognizing pathogens and other endogenous danger stimuli. One of the major cytokines released by innate immune cells is Interleukin (IL)-1. Therefore, we utilize a whole blood stimulation assay in order to measure the secretion of inflammatory cytokines and specifically of the pro-inflammatory cytokine IL-1&beta; 1, 2, 3.
Patients with genetic dysfunctions of the innate immune system causing autoinflammatory syndromes show an exaggerated release of mature IL-1&beta; upon stimulation with LPS alone. In order to evaluate the innate immune component of patients who present with inflammatory-associated pathologies, we use a specific immunoassay to detect cellular immune responses to pathogen-associated molecular patterns (PAMPs), such as the gram-negative bacterial endotoxin, lipopolysaccharide (LPS). These PAMPs are recognized by pathogen recognition receptors (PRRs), which are found on the cells of the innate immune system 4, 5, 6, 7. A primary signal, LPS, in conjunction with a secondary signal, ATP, is necessary for the activation of the inflammasome, a multiprotein complex that processes pro-IL-1&beta; to its mature, bioactive form 4, 5, 6, 8, 9, 10.
The whole blood assay requires minimal sample manipulation to assess cytokine production when compared to other methods that require labor intensive isolation and culturing of specific cell populations. This method differs from other whole blood stimulation assays; rather than diluting samples with a ratio of RPMI media, we perform a white blood cell count directly from diluted whole blood and therefore, stimulate a known number of white blood cells in culture 2. The results of this particular whole blood assay demonstrate a novel technique useful in elucidating patient cohorts presenting with autoinflammatory pathophysiologies.

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&amp;#946; using a Whole Blood Stimulation Assay

We describe a simple immunoassay to measure the production of pro-inflammatory cytokines, such as IL-1 beta production, in patients presenting with autoinflammatory phenotypes. By activating cells in whole blood cultures with pathogen-associated molecular patterns, specifically with lipopolysaccharide, cytokine secretion can be conveniently evaluated in whole blood supernatants.

La medición precisa y simple de la citoquina pro-inflamatoria IL-1β mediante un análisis de sangre entera estimulación

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues ...

Investigación

Medicina

Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

The presence of placental vascular anastomoses is a conditio sine qua non for the development of twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS)1,2. Injection studies of twin placentas have shown that such anastomoses are almost invariably present in monochorionic twins and extremely rare in dichorionic twins1. Three types of anastomoses have been documented: from artery to artery, from vein to vein and from artery to vein. Arterio-venous (AV) anastomoses are unidirectional and are referred to as "deep" anastomoses since they proceed through a shared placental cotyledon, whereas arterio-arterial (AA) and veno-venous (VV) anastomoses are bi-directional and are referred to as "superficial" since they lie on the chorionic plate. Both TTTS and TAPS are caused by net imbalance of blood flow between the twins due to AV anastomoses. Blood from one twin (the donor) is pumped through an artery into the shared placental cotyledon and then drained through a vein into the circulation of the other twin (the recipient). Unless blood is pumped back from the recipient to the donor through oppositely directed deep AV anastomoses or through superficial anastomoses, an imbalance of blood volumes occurs, gradually leading to the development of TTTS or TAPS. The presence of an AA anastomosis has been shown to protect against the development of TTTS and TAPS by compensating for the circulatory imbalance caused by the uni-directional AV anastomoses1,2. 
Injection of monochorionic placentas soon after birth is a useful mean to understand the etiology of various (hematological) complications in monochorionic twins and is a required test to reach the diagnosis of TAPS2. In addition, injection of TTTS placentas treated with fetoscopic laser surgery allows identification of possible residual anastomoses3-5. This additional information is of paramount importance for all perinatologists involved in the management and care of monochorionic twins with TTTS or TAPS. Several placental injection techniques are currently being used. We provide a simple protocol to accurately evaluate the presence of (residual) vascular anastomoses using colored dye injection.

Twin-to-twin transfusion syndrome and twin anemia polycythemia sequence are two potentially devastating problems in perinatal medicine. Both disorders occur only in monochorionic twins and result from unbalanced blood flow through placental vascular anastomoses. We provide a simple protocol to accurately evaluate the presence of vascular anastomoses using colored dye injection of placental vessels after birth.

La evaluación precisa y simple de las anastomosis vasculares en la placenta monocoriónicos con tinte de color

The presence of placental vascular anastomoses is a conditio sine qua non for the development of twin-to-twin transfusion syndrome (TTTS) and twin anemia ...

Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate.

This report provides a detailed description of a new remote navigation system based on magnetic driven forces, which has been recently introduced as a new robotic tool for human cardiac electrophysiology procedures.

Navegación magnética remota de información precisa, la posición del catéter en tiempo real y la ablación en Electrofisiología Cardiaca Procedimientos

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac ...

Assessment of Gastric Emptying in Non-obese Diabetic Mice Using a [13C]-octanoic Acid Breath Test

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used techniques require killing of the animals and postmortem recovery of the meal1,2. This approach prevents longitudinal studies to determine changes in gastric emptying with age and progression of disease. The commonly used [13C]-octanoic acid breath test for humans3 has been modified for use in mice4-6 and rats7 and we previously showed that this test is reliable and responsive to changes in gastric emptying in response to drugs and during diabetic disease progression8. In this video presentation the principle and practical implementation of this modified test is explained. As in the previous study, NOD LtJ mice are used, a model of type 1 diabetes9. A proportion of these mice develop the symptoms of gastroparesis, a complication of diabetes characterized by delayed gastric emptying without mechanical obstruction of the stomach10.
This paper demonstrates how to train the mice for testing, how to prepare the test meal and obtain 4 hr gastric emptying data and how to analyze the obtained data. The carbon isotope analyzer used in the present study is suitable for the automatic sampling of the air samples from up to 12 mice at the same time. This technique allows the longitudinal follow-up of gastric emptying from larger groups of mice with diabetes or other long-standing diseases.

Assessment of Gastric Emptying in Non-obese Diabetic Mice Using a [13C]-octanoic Acid Breath Test

Determination of gastric emptying with a non-invasive [13C]-octanoic acid breath test for tracking gastroparesis in female NOD LtJ mice.

Evaluación del vaciamiento gástrico en ratones diabéticos no obesos mediante un [<sup&gt; 13</sup&gt; C]-octanoico prueba del aliento ácido

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used ...

Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer's Disease and Normal Elderly

Obtaining in vivo human brain tissue volumetrics from MRI is often complicated by various technical and biological issues. These challenges are exacerbated when significant brain atrophy and age-related white matter changes (e.g. Leukoaraiosis) are present. Lesion Explorer (LE) is an accurate and reliable neuroimaging pipeline specifically developed to address such issues commonly observed on MRI of Alzheimer's disease and normal elderly. The pipeline is a complex set of semi-automatic procedures which has been previously validated in a series of internal and external reliability tests1,2. However, LE's accuracy and reliability is highly dependent on properly trained manual operators to execute commands, identify distinct anatomical landmarks, and manually edit/verify various computer-generated segmentation outputs.
LE can be divided into 3 main components, each requiring a set of commands and manual operations: 1) Brain-Sizer, 2) SABRE, and 3) Lesion-Seg. Brain-Sizer's manual operations involve editing of the automatic skull-stripped total intracranial vault (TIV) extraction mask, designation of ventricular cerebrospinal fluid (vCSF), and removal of subtentorial structures. The SABRE component requires checking of image alignment along the anterior and posterior commissure (ACPC) plane, and identification of several anatomical landmarks required for regional parcellation. Finally, the Lesion-Seg component involves manual checking of the automatic lesion segmentation of subcortical hyperintensities (SH) for false positive errors.
While on-site training of the LE pipeline is preferable, readily available visual teaching tools with interactive training images are a viable alternative. Developed to ensure a high degree of accuracy and reliability, the following is a step-by-step, video-guided, standardized protocol for LE's manual procedures.

Lesion Explorer: A Video-guided, Standardized Protocol for Accurate and Reliable MRI-derived Volumetrics in Alzheimer&#039;s Disease and Normal Elderly

Lesion Explorer (LE) is a semi-automatic, image-processing pipeline developed to obtain regional brain tissue and subcortical hyperintensity lesion volumetrics from structural MRI of Alzheimer's disease and normal elderly. To ensure a high level of accuracy and reliability, the following is a video-guided, standardized protocol for LE's manual procedures.

Lesión Explorer: Un video-guiada, Protocolo normalizado para precisa y fiable volumétrica derivados de la RM en la Enfermedad de Alzheimer y normal Ancianos

Obtaining in vivo human brain tissue volumetrics from MRI is often complicated by various technical and biological issues. These challenges are ...

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery.

The current priority in breast cancer radiotherapy is to reduce cardiac doses without compromising target tissue coverage. The voluntary breath-hold technique described here is a simple, inexpensive solution to this problem and capable of being instituted widely without the need for specialized equipment.

Voluntaria Técnica de apnea para la reducción de la dosis del corazón en la izquierda La radioterapia de mama

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these ...

Creating Anatomically Accurate and Reproducible Intracranial Xenografts of Human Brain Tumors

Orthotopic tumor models are currently the best way to study the characteristics of a tumor type, with and without intervention, in the context of a live animal &#8211;&#160;particularly in sites with unique physiological and architectural qualities such as the brain. In vitro and ectopic models cannot account for features such as vasculature, blood brain barrier, metabolism, drug delivery and toxicity, and a host of other relevant factors. Orthotopic models have their limitations too, but with proper technique tumor cells of interest can be accurately engrafted into tissue that most closely mimics conditions in the human brain. By employing methods that deliver precisely measured volumes to accurately defined locations at a consistent rate and pressure, mouse models of human brain tumors with predictable growth rates can be reproducibly created and are suitable for reliable analysis of various interventions. The protocol described here focuses on the technical details of designing and preparing for an intracranial injection, performing the surgery, and ensuring successful and reproducible tumor growth and provides starting points for a variety of conditions that can be customized for a range of different brain tumor models.

The brain is a unique site with qualities that are not well represented by in vitro or ectopic analyses. Orthotopic mouse models with reproducible location and growth characteristics can be reliably created with intracranial injections using a stereotaxic fixation instrument and a low pressure syringe pump.

Crear anatómicamente exactos y reproducibles intracraneal xenoinjertos de tumores cerebrales humanos

Orthotopic tumor models are currently the best way to study the characteristics of a tumor type, with and without intervention, in the context of a live ...

3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue

The developmental goal of 3D ultrasound imaging (3DUS) is to engineer a modality to perform 3D morphological ultrasound analysis of human muscles. 3DUS images are constructed from calibrated freehand 2D B-mode ultrasound images, which are positioned into a voxel array. Ultrasound (US) imaging allows quantification of muscle size, fascicle length, and angle of pennation. These morphological variables are important determinants of muscle force and length range of force exertion. The presented protocol describes an approach to determine volume and fascicle length of m.&#160;vastus lateralis and m.&#160;gastrocnemius medialis. 3DUS facilitates standardization using 3D anatomical references. This approach provides a fast and cost-effective approach for quantifying 3D morphology in skeletal muscles. In healthcare and sports, information on the morphometry of muscles is very valuable in diagnostics and/or follow-up evaluations after treatment or training.

3D ultrasound imaging (3DUS) allows fast and cost-effective morphometry of musculoskeletal tissues. We present a protocol to measure muscle volume and fascicle length using 3DUS.

Proyección de imagen de ultrasonido 3D: morfometría rápida y rentable de tejido músculo-esquelético

The developmental goal of 3D ultrasound imaging (3DUS) is to engineer a modality to perform 3D morphological ultrasound analysis of human muscles. 3DUS ...

Fast Inspection of Quality of Indigo Naturalis by Multiple Light Scattering

Quality control of Chinese herbal medicine is a crucial component of Chinese herbal medicine research and development. Faced with the challenges of modernization and internationalization of Chinese herbal medicine, it is urgent to establish thorough and effective procedures for quality identification of Chinese herbal medicine, and there is an urgent need for new analytical and testing techniques that are efficient, accurate, and environmentally friendly. 
Multiple light scattering is a cutting-edge and analytical method that can accurately and rapidly assess the quality of Chinese herbal medicine without altering the nature or state of the sample or using organic reagents. Indigo Naturalis is considered a good remedy for pediatric hyperthermia, psoriasis, leukemia, and ulcerative colitis. In this study, the process of addition of Indigo Naturalis powder in water was recorded precisely using a multiple light scattering instrument. 
The qualitative and quantitative measurements of the instrument can be used to accurately capture the overall trajectory and sinking behavior of Indigo Naturalis powder into water and to establish a rapid evaluation method for the quality of Indigo Naturalis with the transmission and backscattering spectrograms of the sample as qualitative indicators and stability index as a quantitative indicator. The analytical technique based on multiple light scattering provides a fast, accurate, green, and environmentally friendly method for the quality evaluation of Indigo Naturalis and supports the development and transformation of high-quality Indigo Naturalis.

Here, we present a quality evaluation method based on a multiple light scattering technique to evaluate the quality of Indigo Naturalis.

Inspección rápida de la calidad del índigo natural mediante dispersión múltiple de la luz

Quality control of Chinese herbal medicine is a crucial component of Chinese herbal medicine research and development. Faced with the challenges of ...

Focused Assessment with Sonography for Trauma (FAST) Exam: Image Acquisition

Over the past twenty years, the Focused Assessment with Sonography for Trauma (FAST) exam has transformed the care of patients presenting with a combination of trauma (blunt or penetrating) and hypotension. In these hemodynamically unstable trauma patients, the FAST exam permits rapid and noninvasive screening for free pericardial or peritoneal fluid, the latter of which implicates intra-abdominal injury as a likely contributor to the hypotension and justifies emergent abdominal surgical exploration. Further, the abdominal portion of the FAST exam can also be used outside of the trauma setting to screen for free peritoneal fluid in patients who become hemodynamically unstable in any context, including after procedures that may inadvertently injure abdominal organs. These "non-trauma" situations of hemodynamic instability are often triaged by providers from specialties other than emergency medicine or trauma surgery who are not familiar with the FAST exam. Therefore, there is a need to promulgate knowledge about the FAST exam to all clinicians caring for critically ill patients. Toward this end, this article describes FAST exam image acquisition: patient positioning, transducer selection, image optimization, and exam limitations. Since the free fluid is likely to be found in specific anatomic locations that are unique for each canonical FAST exam view, this work centers on the unique image acquisition considerations for each window: subcostal, right upper quadrant, left upper quadrant, and pelvis.

Focused Assessment with Sonography for Trauma FAST Exam: Image Acquisition

The Focused Assessment with Sonography for Trauma (FAST) exam is a diagnostic point-of-care ultrasound examination used to screen for the presence of free fluid in the pericardium and peritoneum. Indications, techniques, and pitfalls of the procedure are discussed in this article.