Die Autoren danken für die finanzielle Unterstützung von einem National Science Foundation (NSF) die EWG-0540832 mit dem Titel &quot;Mid-Infrared Technologies für Gesundheit und Umwelt (Mirthe)&quot;

1. Vorbereitung der Instrumente <ol><li> Schalten Sie die externe Stromversorgung des Ammoniak optische Sensorplattform, Laser-Diode-Controller, einem speziell angefertigten Steuerelektronik (CEU), der Atem Sampler, Luftpumpe, und Laptop. </li><li> Überprüfen Sie, dass sowohl die Abgas-und Kühlventilatoren der Ammoniaksensor in Betrieb sind. Hinweis: eine in der Rückseite des Sensors befindet, wird die zweite innerhalb des Sensors, die leicht zugänglich ist, gefunden. </li><li> Sicherstellen, dass die akustischen Erfassungsmodul und das Nadelventil Temperatur bei 38,0 ° C, indem die Digitalanzeige auf der Seite der Ammoniaksensor Kasten. Warten Sie etwa 35 Minuten von der Zeit, der Sensor für die Temperaturleistung zu stabilisieren, zur Verfügung gestellt. </li><li> Stellen Zulaufschlauch und Mundstück Temperatur bis 55 ° C, indem Sie auf ein Icon Name &quot;ChangeT&quot; auf dem Desktop des Atem-Sampler gefunden. Die Temperatur kann dann durch Klicken auf den Pfeil nach oben oder unten, gefolgt von einem Klick auf &quot;Upd geändert werdenaß Temp &quot;. Klicken Sie auf &quot;Exit&quot;, um zum Desktop zurückzukehren. Damit das System mindestens 5 min für die Temperatur zu stabilisieren. Aufrechterhalten der Temperatur des Probennehmers und Schläuche auf 55 ° C verringert die Oberflächenverlust von Ammoniak. </li><li> Öffnen Sie die Software auf dem Laptop, die den Ammoniaksensor steuert. Das Programm kann in einem Ordner mit dem Namen &quot;NH 3 Atem-Sensor-Programm&quot; auf den Desktop zugegriffen werden kann. In diesem Ordner, muss der Benutzer auf das Symbol &quot;Haupt LabVIEW-Software&quot; zu wählen. Dieser Ordner enthält mehrere Anwendungen, aber der Benutzer muss &quot;Mainsequence.vi&quot; wählen, um die gewünschte Schnittstelle zugreifen. Wählen Sie &quot;Run&quot; in der oberen linken Ecke des Bildschirms. HINWEIS: Damit beginnt die Sperrlinie Kalibrierungssequenz. Der Laser des QEPAS Monitor arbeitet auf einem optimalen Strom, der während eines automatisierten Leitungssperrprozedur ausgewählt. Dieser Prozess wird etwa 25 Minuten dauern. </li><li> Erstellen Sie eine neue Sitzung auf dem Sampler, so dass each Thema Sitzung hat seine eigene Datei, die auf einem angeschlossenen Flash-Laufwerk gespeichert sind. HINWEIS: Dies wird durch Öffnen des Programms &quot;Breath Sampler&quot; auf dem Desktop des Samplers gefunden durchgeführt. Es gibt Raum, um die Sitzung entsprechend zu identifizieren. Alle während der Sitzung erzeugten Daten werden in dem Flash-Laufwerk unter dieser Kennung gespeichert werden. Das Datum des Experiments ist in der Regel als Teil des Dateinamens verwendet. Die Einlass-und Mundstück Temperatur muss vor dem Eintritt in den Atem-Probenprogramm eingestellt werden. </li><li> Legen Sie eine neue Einweg-Mundstück in das Einlassrohr. Einweghandschuhe tragen, um eine Kontaminierung Mundstück mit Ammoniak aus den Fingern. </li></ol> 2. Atem Probenentnahme HINWEIS: Die relevante Institutional Review Board (Ethikrat) muss jede Studie, die menschlichen Probanden beinhaltet genehmigen. Es gibt viele Faktoren, die den Atem Ammoniak drastisch beeinflussen können. Diese Faktoren können den Atem Ammoniak-Messungen durch eine direkt ändernffecting systemische Ammoniak-Werte werden oder die Reise der Atem Metaboliten von der Lunge zu den Instrumenten. <ol><li> Stellen Sie sicher, Themen kommen an das Labor in einem nüchternen Zustand, nachdem sie keine Nahrung für etwa 12 Stunden bei der Ankunft, und dass sie von der Übung am Morgen vor der Prüfung verzichtet haben verbraucht. </li><li> Sicherzustellen, dass keine Substanz in den Mund für mindestens 1 Stunde vor der Datenerfassung eingeführt. Stellen Sie sicher, dass die Probanden ihre Zähne zu putzen größer als 1 Stunde vor der Prüfung. </li><li> Setzen Sie das Motiv vor der Ammoniaksensor. Weisen Sie das Thema, um das Einlassrohr zu halten, und sicherstellen, dass sie das Mundstück nicht berühren, um Ammoniak Kontamination zu vermeiden. </li><li> Klicken Sie auf &quot;Start&quot; auf dem Sampler-Schnittstelle. Haben das Thema in das Mundstück ausatmen so lange, wie sie können, oder bis der Betreiber hält die Probe ausreichend zu sein. HINWEIS: Dies ist ein Einzelvoll Ausatmung dauert mindestens 10 Sekunden. Munddruck wird in Echtzeit gemessen als Surrogatfür Durchflussrate. Eine farbcodierte Manometer hilft dem Gegenstand herstellen und den gewünschten Ausatmung Druck von 10 cm Wassersäule, die ein Ausatmungsventil Flussrate von 50 ml / sec darstellt. Diese Fließgeschwindigkeit wurde gewählt, da sie von der ATS / ERS für das Protokoll zu bestimmen, Fe NO angenommen wurde. Das Ausatmen Flussrate von Kindern und Erwachsenen zu erreichen ist. Ähnlich sollte drei reproduzierbaren Ausdünstungen erhalten werden, die um weniger als 10% unterscheiden. </li><li> Klicken Sie auf &quot;Stop&quot; auf dem Sampler-Schnittstelle, wenn die Atemprobe ist abgeschlossen. </li></ol> 3. Atem Probenmessung <ol><li> Sobald eine Atemprobe analysiert worden ist, hat der Labortechniker den Monitor in Betrieb, dann die Fähigkeit, jede Segment dieses Atem-Profil analysieren. Der Teil der Atem, der von Interesse ist, ist die Phase-III-Segment. Dies wird durch eine &quot;Plateau&quot; in der Konzentration von Kohlendioxid aus und ist in der mittleren bis späten Stadium der bre gefundenath. </li><li> Wählen Sie den Phase-III-Anteil der Probe, indem die vertikalen Linien auf der Abtaster-Schnittstelle nach rechts vor dem Druckabfall der Luft zu beginnen, wenn Kohlendioxid Plateaus und stoppen. Siehe Abbildung 1 für die Klarstellung. </li><li> Speichern Sie die Daten auf dem Flash-Laufwerk, indem Sie auf &quot;Store&quot; auf dem Sampler Touchscreen-Schnittstelle. </li><li> Sobald die Atemdaten gespeichert wurden, kann der Benutzer &quot;Start&quot;, um eine neue Atemprobe zu initiieren. </li></ol> 4. Veranschaulichung der Auswirkungen von Mundspülung und pH-Wert auf Ammoniakgeruch <ol><li> Probe 3 Atemzüge, um die Grundlinie Ammoniak Ebene zu etablieren. Sicherzustellen, dass Atemzüge mindestens 5 min voneinander gemacht. </li><li> Mund gründlich mit einem 30-ml-Aliquot von Wasser für 60 Sekunden spülen. </li><li> Sammeln Sie eine Atemprobe innerhalb von 60 Sekunden von der Spülung (Abschnitt 2). Sammeln Atemproben im Laufe der nächsten Stunde, um die Änderung in Ammoniak über die Zeit zu beobachten. HINWEIS: Samsätze können so häufig wie jede Minute genommen werden, aber längere Intervalle werden typischerweise verwendet. </li><li> Mund gründlich mit einem 30-ml-Aliquot der Basislösung (Natriumbicarbonat in Wasser) spülen für 60 Sekunden und wiederholen 4.2.1. </li><li> Mund gründlich mit einem 30 ml-Aliquot sauren Lösung für 60 Sekunden Spülen und wiederholen 4.2.1. </li></ol> 5. Veranschaulichung der Auswirkungen von Ein-und Transport-Schläuche Temperaturen auf Ammoniakgeruch <ol><li> Beispiel drei Atemzüge im Laufe von 15 Minuten mit der Einlasstemperatur auf unter Körpertemperatur, etwa 30 ° C eingestellt </li><li> Erhöhen Sie die Temperaturen von Einlass-und Transportschlauch bis 55 ° C bzw. mit einem Desktop-Symbol auf dem Touchscreen-Interface des Atems Sampler. Lassen Sie das System mindestens 5 Minuten stabilen Zustand zu erreichen. </li><li> Probe 3 Atemzügen, 5 min auseinander in die erhitzte Einlaß. </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.

Die Vorteile einer nicht-invasives Verfahren zum Aufspüren von Spuren Metaboliten in Echtzeit auf der Hand. Doch der Bereich der Atem Forschung hat gekämpft, um dieses Potenzial zu erfüllen. Atem-Messung ist ein dynamischer Prozess anfällig für viele Störfaktoren. Unser Ansatz hat wichtige Stärken: nämlich die Empfindlichkeit und Geschwindigkeit der Reis QEPAS basierend Ammoniak-Monitor auf den Atem-Sampler gekoppelt haben uns ermöglicht, zu bewerten und zu identifizieren Atem Sammlung relevante Faktoren, um ei...

Ammoniak ist ein Nebenprodukt der allgegenwärtigen Eiweißstoffwechsel ein. Ammoniak-Messung kann somit dazu beitragen, Ärzte beurteilen verschiedene Krankheitszustände und Wellness 2. Allerdings ist Ammoniak schwierig, genau zu messen, über Blut-oder Atem, denn es ist sehr reaktiv. Obwohl häufig verwendet werden, haben Bluttests zahlreiche Nachteile, einschließlich der grundlegenden Bedenken hinsichtlich Genauigkeit 3. Aber das große Problem mit Blut-Tests ist die Realität, dass sie immer nur episodisch gesammelt. Dies ist wichtig, da Ammoniak Physiologie, ähnlich wie Blutzucker und viele andere Stoffwechselprozesse, sind fließend und ständig wechselnden 4. Im Gegensatz dazu sind Atem-Tests vollständig nicht-invasive und schnell, so dass dadurch leicht wiederholten Maßnahmen. So ist Atem Ammoniak Mess attraktiv, weil es eine ernste ungedeckten Bedarf in einer einzigartigen Weise zu adressieren. Atem-Sammlung stellt jedoch einzigartig Bedenken. Während Aderlass von Natur trägt die jeobei der Atmung mit der Mundschleimhaut Variabilität, Verschmutzung: Pardy Fehler in mehreren unvorhersehbare Weise (zB Tourniquet Zeit, Schweiß Verschmutzung, Blutzell Hämolyse, Verzögerung bei der Labormessung, usw. 5), Atem-Messung müssen die Forscher mit einer anderen Gruppe von neuen Herausforderungen zu kämpfen oder bakterielle Ammoniak, Einfluss der Umgebungsluft und Gerät Feuchtigkeit und Temperatur, usw. 6. In der Tat ist es nicht ratsam, die Aufgabe in Verbindung experimentelle Ausstattung für Menschen mit experimentellen Verfahren zu entdecken, unbekannte Biologie unterschätzen. In Teil wegen dieser Hindernisse hat Atem Ammoniak noch nicht erfüllt sein Potenzial. Hier präsentieren wir unseren Atem Ammoniak Messprotokoll für die schnelle und genaue Ergebnisse. Unser Protokoll hat Kraft in drei Bereichen: der Monitor, die Schnittstelle Sampler, und die Aufmerksamkeit auf die menschliche Einflüsse. Der Monitor wurde von den Kollegen an der Rice University, wie zuvor beschrieben 7 gebaut. Die Basis der MEAsung ein Quarz verbesserte photoakustische Spektroskopie (QEPAS) Technik, die eine piezoelektrische Quarz Stimmgabel nach einem akustischen Wandler verwendet. Photoakustische Effekt tritt auf, wenn Schallwellen werden durch die Absorption der Laserstrahlung moduliert wird, indem Zielspurengase erzeugt. Das Spurengas unter Verwendung eines akustischen Zelle, die akustisch an die Resonanzfrequenz moduliert wird detektiert. Eine Absorptionswellenlänge für Ammoniak wurde ausgewählt, die frei von spektralen Interferenzen von störenden Arten in Atem. Für die Zwecke der menschlichen Ausatemluft Messung, die wichtigsten Merkmale der Monitor umfassen eine große Messbereich (von ~ 50 Teilen pro Milliarde, ppb bis mindestens 5000 ppb) und Geschwindigkeit (1 sec. Messungen). Die Geschwindigkeit des Monitors ermöglicht Zeitauflösung in der gesamten Atemzyklus. Der Monitor ist mit einem speziell entwickelten Atem-Sampler gekoppelt. Der Probennehmer besteht aus einem Drucksensor und capnograph. Es zeigt und archiviert EchtzeitMessungen der Munddruck und Kohlendioxid sowie die Ammoniakkonzentration durch den Sensor bestimmt wird. Dieses Tool daher ermöglicht dem Techniker, die Qualität der Atemaufwand zu bewerten, da der Atem gesammelt. Dies ermöglicht uns, die Empfehlungen für die Analyse von Atem Stickstoffmonoxid (NO Fe) von Task Force der American Thoracic Society / European Respiratory Society (ATS / ERS) 8 vorgeschlagen überschreiten. Für alle Atemproben wurde ein Einweg-Einweg-In-Line-Ventil an der Mund-Port des Atem-Sampler verwendet. Aufgrund der Geschwindigkeit des durch den Abtaster vorgesehen Monitor und die Qualitätskontrollen, waren wir in der Lage, genau zu beurteilen menschliche Einflüsse 9. Die meisten Themen, zum Beispiel, zunächst hyperventilieren, wenn angewiesen, um zu atmen. Andere wichtige Einflüsse, wie oralen pH und Mundspülungen, Temperaturen des Samplers, zu überwachen und alle zugehörigen Schläuche, und die Art der Atmung, wurden dann untersucht, und die Basis for die beispielhaften Experimente unten. Schließlich, und vielleicht am wichtigsten ist, muß betont werden, daß mehrere Gruppen erfahrenen Mess Atem Ammoniak mit ganz anderen Sensoren und Messverfahren. Diese können wichtige Vorteile und Gültigkeit. Eine vollständige Vergleich würde den Rahmen der vorliegenden Arbeit 10,11,12.

<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.

Themen zu erwarten, dass eine Vielzahl von Basis Atem Ammoniak-Werte zu erzeugen. Gesunde Personen können den Tag mit einem Hauch von Ammoniak Messung 100-1000 ppb beginnen. Spülen Sie den Mund mit jeder Flüssigkeit sofort ändert sich die Menge an nachweisbarem Atem Ammoniak. Neutrale und saure Flüssigkeiten in der Regel um mehr als die Hälfte reduziert die Menge der beobachtbaren Ammoniak. Diese Niveaus dann zum Ausgangswert zurück, wie die Auswirkungen der Spülung nachlässt. Die Auswirkungen von Wasser schein...

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.

Schnelle und genaue Messung der ausgeatmeten Luft Ammoniak

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 Aufrufe.  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.

Serie: 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&#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.

Genaue und einfache Messung der pro-inflammatorischen Zytokins IL-1β mit einem Vollblut Stimulation Assay

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

Forschung

Medizin

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.

Präzise und einfache Auswertung der Gefäßanastomosen in Monochoriale Placenta mit Farbstoff

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.

Remote-Magnetic Navigation für präzise, ​​Echtzeit-Positionierung und Katheter Ablation in Cardiac Elektrophysiologie Procedures

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

The Measurement and Treatment of Suppression in Amblyopia

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current estimates put the prevalence of amblyopia at approximately 1-3%1-3, the majority of cases being monocular2. Amblyopia is most frequently caused by ocular misalignment (strabismus), blur induced by unequal refractive error (anisometropia), and in some cases by form deprivation.
Although amblyopia is initially caused by abnormal visual input in infancy, once established, the visual deficit often remains when normal visual input has been restored using surgery and/or refractive correction. This is because amblyopia is the result of abnormal visual cortex development rather than a problem with the amblyopic eye itself4,5 . Amblyopia is characterized by both monocular and binocular deficits6,7 which include impaired visual acuity and poor or absent stereopsis respectively. The visual dysfunction in amblyopia is often associated with a strong suppression of the inputs from the amblyopic eye under binocular viewing conditions8. Recent work has indicated that suppression may play a central role in both the monocular and binocular deficits associated with amblyopia9,10 .
Current clinical tests for suppression tend to verify the presence or absence of suppression rather than giving a quantitative measurement of the degree of suppression. Here we describe a technique for measuring amblyopic suppression with a compact, portable device11,12 . The device consists of a laptop computer connected to a pair of virtual reality goggles. The novelty of the technique lies in the way we present visual stimuli to measure suppression. Stimuli are shown to the amblyopic eye at high contrast while the contrast of the stimuli shown to the non-amblyopic eye are varied. Patients perform a simple signal/noise task that allows for a precise measurement of the strength of excitatory binocular interactions. The contrast offset at which neither eye has a performance advantage is a measure of the "balance point" and is a direct measure of suppression. This technique has been validated psychophysically both in control13,14 and patient6,9,11 populations.
In addition to measuring suppression this technique also forms the basis of a novel form of treatment to decrease suppression over time and improve binocular and often monocular function in adult patients with amblyopia12,15,16 . This new treatment approach can be deployed either on the goggle system described above or on a specially modified iPod touch device15.

Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.

Die Messung und Behandlung von Unterdrückung in Amblyopie

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current ...

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.

Beurteilung der Magenentleerung in Non-adipösen diabetischen Mäusen mit a [<sup&gt; 13</sup&gt; C]-Octansäure Atemtest

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 (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.

Läsion Explorer: Ein Video-geführt, standardisiertes Protokoll für genaue und zuverlässige MRI-abgeleiteten Volumetrics in der Alzheimer-Krankheit und Normale Ältere

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.

Freiwillige Atemanhaltetechnik zur Verringerung der Herz-Dose in der linken Brust Strahlentherapie

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.

Erstellen Anatomisch genaue und reproduzierbare intrakranielle Xenografts der Menschen Hirntumoren

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.

3D Ultraschall-Bildgebung: schnelle und kostengünstige Morphometrie des Muskel-Skelett-Gewebe

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.

Schnelle Qualitätsprüfung von Indigo Naturalis durch mehrfache Lichtstreuung

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