Les auteurs reconnaissent l&#39;appui financier de la National Science Foundation (NSF) accorder CEE-0540832 intitulé &quot;Technologies mi-infrarouge pour la santé et l&#39;environnement (MIRTHE)&quot;

1. Préparation des instruments <ol><li> Allumez l&#39;alimentation externe à la plate-forme de capteur optique de l&#39;ammoniac, contrôleur de diode laser, une unité électronique de commande sur mesure (CEU), l&#39;échantillonneur de souffle, pompe à air, et un ordinateur portable. </li><li> Vérifier que les deux gaz d&#39;échappement et un ventilateur de refroidissement du capteur d&#39;ammoniac sont en fonctionnement. NOTE: L&#39;une est située à l&#39;arrière de la sonde, le second se trouve à l&#39;intérieur du capteur, qui est facilement accessible. </li><li> S&#39;assurer que le module de détection acoustique et la température aiguille de soupape sont à 38,0 ° C en contrôlant l&#39;affichage digital situé sur le côté de la boîte de capteur d&#39;ammoniac. Attendez environ 35 minutes à partir du moment que le capteur est fourni pour pouvoir la température se stabilise. </li><li> Réglez la tubulure d&#39;entrée et la température de l&#39;embout à 55 ° C en cliquant sur le nom de l&#39;icône &quot;ChangeT&quot; trouvé sur le bureau de l&#39;échantillonneur de souffle. La température peut alors être changée en cliquant sur la flèche vers le haut ou vers le bas puis en cliquant sur &quot;Updmangé Temp &quot;. Cliquez sur &quot;Exit&quot; pour revenir au bureau. Permettre au système d&#39;au moins 5 min à la température de se stabiliser. Le maintien de la température de l&#39;échantillonneur et les tubes à 55 ° C minimise la perte d&#39;ammoniac de surface. </li><li> Ouvrir le logiciel sur l&#39;ordinateur qui commande le capteur d&#39;ammoniac. Le programme peut être consulté dans un dossier nommé &quot;NH 3 Breath Programme capteur&quot; sur le bureau. Dans ce dossier, l&#39;utilisateur doit sélectionner l&#39;icône &quot;logiciel LabVIEW principale&quot;. Ce dossier contient plusieurs applications, mais l&#39;utilisateur doit sélectionner &quot;Mainsequence.vi&quot; pour accéder à l&#39;interface souhaitée. Sélectionnez «run» dans le coin supérieur gauche de l&#39;écran. NOTE: Cela commence la ligne de verrouillage séquence d&#39;étalonnage. Le laser de l&#39;écran QEPAS fonctionne sur un courant optimal, qui est choisi au cours d&#39;une procédure de verrouillage de ligne automatisée. Ce processus prendra environ 25 minutes. </li><li> Créer une nouvelle session sur l&#39;échantillonneur tels que eaobjet session ch dispose de son propre fichier enregistré sur un lecteur flash ci-joint. NOTE: Ceci est réalisé par l&#39;ouverture du programme &quot;Breath Sampler&quot; trouvé sur le bureau de l&#39;échantillonneur. Il ya un espace pour identifier la session appropriée. Toutes les données obtenues au cours de la session seront enregistrés dans le lecteur flash sous cet identifiant. Le jour de l&#39;expérience, est généralement utilisé comme une partie du nom de fichier. L&#39;entrée et la température de l&#39;embout buccal doivent être réglées avant d&#39;entrer dans le programme souffle-échantillonnage. </li><li> Insérez un nouveau porte-parole disponible dans le tuyau d&#39;entrée. Porter des gants jetables pour éviter la contamination embout avec de l&#39;ammoniac à partir de doigts. </li></ol> 2. Souffle de prélèvement des échantillons NOTE: Le comité d&#39;examen institutionnel pertinent (comité d&#39;éthique) doit approuver toute étude sur des sujets humains. Il ya beaucoup de facteurs qui peuvent influencer considérablement le souffle de l&#39;ammoniac. Ces facteurs peuvent modifier les mesures d&#39;ammoniac souffle directement par unffecting niveaux d&#39;ammoniac systémiques ou en affectant le voyage de métabolites de respiration des poumons à l&#39;instrumentation. <ol><li> Assurez sujets arrivent au laboratoire dans un état de jeûne, après avoir consommé aucune nourriture pendant environ 12 heures à l&#39;arrivée et qu&#39;ils se sont abstenus de l&#39;exercice le matin avant le test. </li><li> Assurez-vous qu&#39;aucune substance a été introduite dans la bouche pendant au moins 1 heure avant la collecte des données. Veiller à ce que les sujets se brossent les dents supérieure à 1 heure avant le test. </li><li> Seat l&#39;objet devant le capteur d&#39;ammoniac. Demandez au sujet de tenir le tuyau d&#39;entrée, et assurez-vous qu&#39;ils ne touchent pas l&#39;embout buccal pour éviter la contamination de l&#39;ammoniac. </li><li> Cliquez sur &quot;Démarrer&quot; sur l&#39;interface de l&#39;échantillonneur. Avez-sujet expirer dans l&#39;embout buccal pour aussi longtemps qu&#39;ils le peuvent, ou jusqu&#39;à ce que l&#39;opérateur estime que l&#39;échantillon soit suffisante. NOTE: Il s&#39;agit d&#39;une seule expiration plein durant au moins 10 secondes. pression de la bouche est mesurée en temps réel comme un substitutpour le débit. Un manomètre à code couleur aide le sujet produisent et maintiennent la pression d&#39;expiration souhaitée de 10 cm d&#39;eau, ce qui représente un taux de 50 ml / s de débit expiratoire. Ce débit a été choisi car il a été adopté par l&#39;ATS / ERS pour le protocole pour déterminer Fe NO. Ce débit expiratoire est réalisable par les enfants et les adultes. De la même façon trois exhalations reproductibles peuvent être obtenus qui diffèrent de moins de 10%. </li><li> Cliquez sur &quot;Stop&quot; sur l&#39;interface de l&#39;échantillonneur lorsque l&#39;échantillon d&#39;haleine est terminée. </li></ol> 3. Un échantillon d&#39;haleine mesure <ol><li> Une fois un échantillon d&#39;haleine a été analysé, le technicien de laboratoire d&#39;utiliser le moniteur a alors la capacité d&#39;analyser n&#39;importe quel segment de ce profil de souffle. Le passage de la respiration qui est d&#39;intérêt est le segment de phase III. Elle est caractérisée par un &quot;plateau&quot; de la concentration en dioxyde de carbone et se trouve au milieu de stade tardif de la BREath. </li><li> Sélectionnez la partie III phase de l&#39;échantillon en faisant glisser les lignes verticales sur l&#39;interface de l&#39;échantillonneur de commencer lorsque les plateaux de dioxyde de carbone et d&#39;arrêter juste avant la chute de pression du souffle. Voir la Figure 1 pour des précisions. </li><li> Enregistrez les données sur le lecteur flash en cliquant sur &quot;Store&quot; sur l&#39;interface de l&#39;écran tactile échantillonneur. </li><li> Une fois les données d&#39;haleine ont été stockés, l&#39;utilisateur peut sélectionner &quot;Démarrer&quot; pour lancer un nouvel échantillon d&#39;haleine. </li></ol> 4. Illustrant les effets de bain de bouche et du pH sur Breath ammoniac <ol><li> Exemple de 3 respirations pour établir le niveau de base d&#39;ammoniac. S&#39;assurer que les respirations sont prises au moins 5 minutes l&#39;un de l&#39;autre. </li><li> Rincer soigneusement la bouche avec un 30 ml aliquote de l&#39;eau pendant 60 secondes. </li><li> Prélever un échantillon d&#39;haleine dans les 60 secondes de rinçage (Section 2). Prélever des échantillons d&#39;haleine au cours de la prochaine heure pour observer le changement dans l&#39;ammoniac au fil du temps. REMARQUE: Samples peut être pris aussi souvent que chaque minute, mais des intervalles plus longs sont généralement utilisés. </li><li> Rincer soigneusement la bouche avec un 30 ml aliquote de la solution de base (bicarbonate de sodium dans l&#39;eau) pendant 60 secondes et répétez 4.2.1. </li><li> Rincer soigneusement la bouche avec un 30 ml aliquote de la solution acide pendant 60 secondes et répétez 4.2.1. </li></ol> 5. Illustrant les effets de l&#39;entrée et des transports tubes températures sur Breath ammoniac <ol><li> Exemples trois respirations au cours de 15 min avec la température d&#39;entrée fixés au-dessous de la température du corps, d&#39;environ 30 ° C. </li><li> Augmenter la température des tubulures d&#39;entrée et de transport à 55 ° C respectivement en utilisant une icône du bureau sur l&#39;interface de l&#39;écran tactile de l&#39;échantillonneur de souffle. Laisser le système au moins 5 minutes pour atteindre l&#39;état d&#39;équilibre. </li><li> Échantillon 3 respirations, 5 min à part dans l&#39;entrée chauffée. </li></ol>

<ol>
	<li>Adeva, M. M., Souto, G., Blanco, N., Donapetry, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonium+metabolism+in+humans.">Ammonium metabolism in humans.</a> Metabolism: clinical and experimental. 61 (11), 1495-1511 (2012).</li><li>Auron, A., Brophy, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperammonemia+in+review:+pathophysiology,+diagnosis,+and+treatment.">Hyperammonemia in review: pathophysiology, diagnosis, and treatment.</a> Pediatric nephrology. 27 (2), 207-222 (2012).</li><li>Blanco Vela, C. I., Bosques Padilla, F. J. <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+concentrations+in+cirrhosis+patients-still+confusing+after+all+these+years.">Determination of ammonia concentrations in cirrhosis patients-still confusing after all these years.</a> Annals of hepatology. 10 Suppl 2, (2011).</li><li>Mpabanzi, L., Ol de Damink, S. W. M., van de Poll, M. C. G., Soeters, P. B., Jalan, R., Dejong, C. H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=To+pee+or+not+to+pee:+ammonia+hypothesis+of+hepatic+encephalopathy+revisited.">To pee or not to pee: ammonia hypothesis of hepatic encephalopathy revisited.</a> European journal of gastroenterology &amp; hepatology. 23 (6), 449-454 (2011).</li><li>Goggs, R., Serrano, S., Szladovits, B., Keir, I., Ong, R., Hughes, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+investigation+of+a+point-of-care+blood+ammonia+analyzer.">Clinical investigation of a point-of-care blood ammonia analyzer.</a> Veterinary clinical pathology / American Society for Veterinary Clinical Pathology. 37 (2), 198-206 (2008).</li><li>Huizenga, J. R., Tangerman, A., Gips, C. 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. European Respiratory Society. Recommendations for Standardized Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory Nitric Oxide and Nasal Nitric Oxide.</a> American journal of respiratory and critical care medicine. 171 (8), 912-930 (2005).</li><li>Solga, S. F., 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=Factors+influencing+breath+ammonia+determination.">Factors influencing breath ammonia determination.</a> Journal of breath research. 7 (3), (2013).</li><li>Schmidt, F. 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=Ammonia+in+breath+and+emitted+from+skin.">Ammonia in breath and emitted from skin.</a> Journal of breath research. 7 (1), (2013).</li><li>Span&#283;l, P., Dryahina, K., Smith, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+quantitative+study+of+the+influence+of+inhaled+compounds+on+their+concentrations+in+exhaled+breath.">A quantitative study of the influence of inhaled compounds on their concentrations in exhaled breath.</a> Journal of breath research. 7 (1), (2013).</li><li>Boots, A. W., van Berkel, J. J. B. N., Dallinga, J. W., Smolinska, A., Wouters, E. F., van Schooten, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+versatile+use+of+exhaled+volatile+organic+compounds+in+human+health+and+disease.">The versatile use of exhaled volatile organic compounds in human health and disease.</a> Journal of breath research. 6 (2), (2012).</li><li>Hibbard, T., Killard, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breath+ammonia+levels+in+a+normal+human+population+study+as+determined+by+photoacoustic+laser+spectroscopy.">Breath ammonia levels in a normal human population study as determined by photoacoustic laser spectroscopy.</a> Journal of breath research. 5 (3), (2011).</li><li>Wang, T., Pysanenko, A., Dryahina, K., Span&#283;l, P., Smith, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+breath,+exhaled+via+the+mouth+and+nose,+and+the+air+in+the+oral+cavity.">Analysis of breath, exhaled via the mouth and nose, and the air in the oral cavity.</a> Journal of breath research. 2 (3), (2008).</li><li>Amann, A., Smith, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Volatile Biomarkers. 1st Edition. , (2013).</li></ol>

Dr. Risby serves as a consultant for Loccioni Humancare the manufacturer of the breath sampler.

Les avantages d&#39;une procédure non invasive capable de détecter les métabolites de trace en temps réel sont évidents. Cependant, le domaine de la recherche de souffle a du mal à réaliser ce potentiel. mesure de la respiration est un processus dynamique vulnérables à de nombreux facteurs de confusion. Notre approche a des atouts importants: en particulier, la sensibilité et la vitesse du riz QEPAS ammoniac basé sur le moniteur couplé à l&#39;échantillonneur de souffle nous ont permis d&#39;évaluer et d&...

L&#39;ammoniac est un sous-produit ubiquitaire du métabolisme des protéines 1. mesure de l&#39;ammoniac peut donc aider les cliniciens à évaluer diverses maladies et états de bien-être 2. Cependant, l&#39;ammoniac est difficile à mesurer avec précision, par le sang ou d&#39;haleine, car il est très réactif. Bien que couramment utilisé, les tests sanguins présentent de nombreux inconvénients, y compris les préoccupations de base sur la précision 3. Mais le problème majeur avec les tests sanguins est la réalité que ne jamais ils ont recueilli de façon épisodique. Ceci est important parce que la physiologie de l&#39;ammoniac, un peu comme le glucose dans le sang et de nombreux autres processus métaboliques, sont fluides et en constante évolution 4. En revanche, les tests d&#39;haleine sont entièrement non-invasive et rapide, ce qui permet facilement de mesures répétées. Ainsi, la mesure de l&#39;ammoniac de souffle est intéressante, car elle peut répondre à un besoin non satisfait grave d&#39;une manière unique. collection Breath, présente toutefois des préoccupations particulières. Considérant que la saignée porte intrinsèquement le jeopardy d&#39;erreur de plusieurs manières imprévisibles (par exemple, le temps garrot, la contamination de la sueur, l&#39;hémolyse des globules, retard dans la mesure de laboratoire, etc 5), les chercheurs de mesure du souffle doit composer avec un groupe différent, de nouveaux défis: la variabilité dans la respiration, la contamination par la muqueuse buccale ou de l&#39;ammoniac bactérienne, l&#39;influence de l&#39;air ambiant et un appareil humidité et de température, etc 6. En effet, il est imprudent de sous-estimer la tâche dans la connexion de matériel expérimental pour les humains en utilisant des procédures expérimentales pour découvrir la biologie inconnu. En partie en raison de ces obstacles, le souffle de l&#39;ammoniac n&#39;a pas encore atteint son potentiel. Ici, nous vous présentons notre protocole de mesure de l&#39;ammoniac de souffle pour des résultats rapides et précis. Notre protocole a la force dans trois domaines: le moniteur, l&#39;échantillonneur de l&#39;interface, et l&#39;attention sur les influences humaines. Le moniteur a été construit par des collègues de l&#39;Université Rice, comme décrit précédemment 7. La base de la measurement une amélioration de la spectroscopie photoacoustique de quartz (QEPAS) technique qui emploie un piézoélectrique diapason de quartz comme un transducteur acoustique. Effet photo-acoustique se produit lorsque les ondes acoustiques sont produites par l&#39;absorption du rayonnement laser modulé par des espèces de gaz en traces cibles. Le gaz marqueur est détecté en utilisant une cellule acoustique qui est acoustiquement résonnante à la fréquence modulée. Une longueur d&#39;onde d&#39;absorption de l&#39;ammoniac a été choisi qui est libre d&#39;interférences spectrales d&#39;interférer espèces en haleine. Aux fins de la mesure de l&#39;air expiré humaine, les principales caractéristiques du moniteur comprennent une large gamme de mesure (de ~ 50 parties par milliard, ppb à au moins 5000 ppb) et la vitesse (1 mesures sec). La vitesse de l&#39;écran permet à résolution dans le temps tout au long du cycle de respiration. Le moniteur est couplé à un échantillonneur de souffle spécialement conçu. L&#39;échantillonneur se compose d&#39;un capteur de pression et capnographe. Il affiche et Archives temps réeldes mesures de pression de la bouche et du dioxyde de carbone, ainsi que les concentrations d&#39;ammoniac déterminées par le capteur. Cet échantillonneur, par conséquent, permet au technicien d&#39;évaluer la qualité de l&#39;effort de souffle que le souffle est recueilli. Cela nous permet de dépasser les recommandations pour l&#39;analyse souffle de l&#39;oxyde nitrique (NO Fe) proposé par le Groupe de travail de l&#39;American Thoracic Society / European Respiratory Society (ATS / ERS) 8. Pour tous les échantillons d&#39;haleine, une vanne à une voie disponible en ligne a été utilisé sur l&#39;orifice d&#39;embouchure de l&#39;échantillonneur d&#39;haleine. En raison de la vitesse de l&#39;écran et les contrôles de qualité fourni par l&#39;échantillonneur, nous avons pu évaluer soigneusement les influences humaines 9. La plupart des sujets, par exemple, l&#39;hyperventilation initialement sur instructions de respirer. D&#39;autres influences importantes, telles que pH buccal et bains de bouche, les températures de l&#39;échantillonneur, moniteur et tous les tubes associés, et le mode de respiration, ont ensuite été étudiés, et sont à la base for les expériences illustration ci-dessous. Enfin, et peut-être plus important encore, il faut souligner que plusieurs groupes très expérimentés mesurent souffle ammoniac entièrement à l&#39;aide de différents capteurs et méthodes de mesure. Ceux-ci peuvent avoir des avantages importants et validité. Une comparaison est complète au-delà de la portée de la présente 10,11,12 de travail.

<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.

Les sujets peuvent être tenus de produire un large éventail de niveaux d&#39;ammoniac à couper le souffle de base. Personnes en bonne santé peuvent commencer la journée avec une mesure de l&#39;ammoniac de souffle de 100-1,000 ppb. Rincer la bouche avec tout fluide change immédiatement le montant de l&#39;ammoniac décelable souffle. Généralement fluides neutres et acides couper la quantité d&#39;ammoniac observable par plus de la moitié. Ces niveaux retournent ensuite à la ligne de base que les effets de l&#...

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.

Rapide et précis expiré Breath ammoniac mesure

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

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JoVE Journal

Medicine

13.1K vues.  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.

Vidéo: 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.

Mesure précise et simple de la cytokine pro-inflammatoire IL-1β en utilisant un dosage de sang total Stimulation

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

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Médecine

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.

Évaluation précise et simple des anastomoses vasculaires dans le placenta monochoriales utilisant colorant

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.

Navigation magnétique à distance pour exacts, positionnement du cathéter en temps réel et en électrophysiologie cardiaque Ablation Procédures

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.

Évaluation de la vidange gastrique chez des souris diabétiques non obèses aide d&#39;un [<sup&gt; 13</sup&gt; C]-octanoïque test respiratoire à l&#39;acide

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.

Lésion Explorer: Un Protocole de vidéo-guidée standardisé pour Volumetrics IRM dérivées exactes et fiables dans la maladie d&#39;Alzheimer et normale personnes âgées

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.

Volontaire Technique apnée pour la réduction de coeur dose en radiothérapie du sein gauche

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.

Création anatomique précise et reproductible intracrânienne xénogreffes de tumeurs cérébrales humaines

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.

L’échographie 3D : morphométrie rapide et rentable des tissus musculo-squelettiques

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.

Inspection rapide de la qualité de l’Indigo Naturalis par diffusion multiple de la lumière

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.