This work was supported by NIH HL-10342

NOTA: Todos os protocolos de animais foram aprovados pelo Comitê Universidade Animal Care and Use a Johns Hopkins. 1. Preparação de animais <ol><li> Prepare ratos 6 C57BL / 6 de controle para a medição Dfco, anestesiando-los com cetamina e xilazina, conforme descrito no passo 2.3 abaixo. </li><li> Preparar todos os outros ratinhos com os diferentes patologias pulmonares mostrados na Tabela 1, utilizando o mesmo procedimento que para os controlos. Detalhes específicos necessários para estabelecer cada um destes modelos são encontrados nas referências relevantes. Os ratos de controlo e os dos outros grupos patológicos são todos 6-12 semanas de idade. </li></ol> 2. Medição do Fator de Difusão de monóxido de carbono (Dfco) <ol><li> Configure o módulo cromatógrafo a gás fornecido com o equipamento para medir os picos de nitrogênio, oxigênio, néon, e monóxido de carbono. Para este uso aplicação apenas os dados de néon e CO. NOTA: Este instrumento utiliza um s molecularescoluna IEVE com hélio como gás de transporte, com 12,00 mm filme, 320,00 mm ID e 10 m de comprimento. A coluna de cromatografia tem um volume de 0,8 ml, mas utilizou-se 2 ml para assegurar adequada compensação da tubagem de ligação com a amostra. </li><li> No início de cada dia experimental, antes de se efectuarem as medições das amostras a partir dos ratinhos, tomar uma amostra de 2 ml directamente a partir de um saco de mistura de gás que contém cerca de 0,5% Ne, 0,5% de CO, e equilibrar ar, e usar esta amostra para calibrar o cromatógrafo a gás. </li><li> Anestesiar ratos com cetamina (90 mg / kg) e xilazina (15 mg / kg), e confirmar a anestesia pela ausência do reflexo do movimento. Aplicar pomada veterinária sobre os olhos para evitar o ressecamento. Tracheostomize os ratos com uma cânula de agulha stub (18 g em adultos ou 20 G em muito jovem ratos). NOTA: O Dfco é completada em menos de 10 minutos após a anestesia e antes de qualquer ventilação mecânica ou outros procedimentos. </li><li> Em ratinhos superiores a 6 semanas de idade, usar uma seringa de 3 ml to retirar 0,8 ml de gás a partir do saco de mistura de gás. Ligar a seringa para a cânula traqueal e rapidamente inflar o pulmão. Usando um metrônomo, conte 9 seg, e então rapidamente retirar os 0,8 ml (no ar expirado). </li><li> Diluir esta retirados 0,8 ml ar exalado para 2 ml com ar ambiente, deixe-a descansar por pelo menos 15 segundos. Em seguida, injetar toda a amostra no cromatógrafo a gás para análise. </li><li> Ao analisar esta primeira amostra Dfco, inflar o pulmão do rato com um segundo de 0,8 ml do saco de mistura de gases, e, em seguida, processar esta amostra idêntica à primeira amostra. Calcular a média das duas medidas Dfco. NOTA: Para medições em ratos jovens como de 2 semanas de idade, usar um volume de 0,4 ml, 0,8 ml é desde um volume demasiado importante para fazer medições em pulmões de ratos muito jovens. É preferível utilizar o volume de 0,8 ml para os ratinhos mais velhos de 6 semanas, e que, se o volume de 0,4 ml é necessária para alguns ratinhos, que deve ser utilizado de forma consistente para todos os ratinhos no grupo a ser estudados. </li><li> Calcule Dfcocomo 1 - (CO 9 / CO c) / (Ne 9 / Ne c), onde C e 9 subscritos referem-se as concentrações dos gases de calibração injetados e os gases removidos após um 9 seg tempo apneia, respectivamente. </li><li> Analisar e comparar as diferenças com um one-way ANOVA e avaliar o nível de significância com correção de Tukey para comparações múltiplas em todos os ratos de coorte. Considere p &lt;0,05 como significativo. NOTA: Todos os ratos usados ​​aqui foram parte de estudos experimentais envolvendo várias medições posteriores de ventilação pulmonar, mecânica, lavagem pulmonar, ou histologia, que não são aqui relatados. Além disso, uma vez que o método é o mesmo em todos os modelos experimentais como foi feito acima nos ratinhos de controlo, somente os resultados de vários modelos patológicos são apresentados. Informação adicional sobre estes modelos é apresentada na tabela suplementar. </li><li> Eutanásia os animais por anestesia profundasobredosagem tic seguido por deslocamento cervical ou decapitação. Sempre que necessário, remover as células e / ou tecidos do pulmão dos ratos mortos para mais biológico ou processamento histológico e análise. </li></ol>

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W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+standardized+breath+holding+technique+for+the+clinical+measurement+of+the+diffusing+capacity+of+the+lung+for+carbon+monoxide.">A standardized breath holding technique for the clinical measurement of the diffusing capacity of the lung for carbon monoxide.</a> J Clin Invest. 36 (1 Pt 1), 1-17 (1957).</li><li>Miller, A., Warshaw, R., Nezamis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusing+capacity+and+forced+vital+capacity+in+5,003+asbestos-exposed+workers:+Relationships+to+interstitial+fibrosis+(ILO+profusion+score)+and+pleural+thickening.">Diffusing capacity and forced vital capacity in 5,003 asbestos-exposed workers: Relationships to interstitial fibrosis (ILO profusion score) and pleural thickening.</a> Am J Ind Med. 56 (12), 1383-1393 (2013).</li><li>Enelow, R. I., 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=Structural+and+functional+consequences+of+alveolar+cell+recognition+by+CD8(+)+T+lymphocytes+in+experimental+lung+disease.">Structural and functional consequences of alveolar cell recognition by CD8(+) T lymphocytes in experimental lung disease.</a> J Clin Invest. 102 (9), 1653-1661 (1998).</li><li>Hartsfield, C. L., Lipke, D., Lai, Y. L., Cohen, D. A., Gillespie, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+mechanical+and+immunologic+dysfunction+in+a+murine+model+of+AIDS.">Pulmonary mechanical and immunologic dysfunction in a murine model of AIDS.</a> Am J Physiol. 272 (4 Pt 1), 699-706 (1997).</li><li>Wegner, C. D., 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=Intercellular+adhesion+molecule-1+contributes+to+pulmonary+oxygen+toxicity+in+mice:+role+of+leukocytes+revised.">Intercellular adhesion molecule-1 contributes to pulmonary oxygen toxicity in mice: role of leukocytes revised.</a> Lung. 170 (5), 267-279 (1992).</li><li>Reinhard, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inbred+strain+variation+in+lung+function.">Inbred strain variation in lung function.</a> Mamm Genome. 13 (8), 429-437 (2002).</li><li>Sabo, J. P., Kimmel, E. C., Diamond, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+the+Clara+cell+toxin,+4-ipomeanol,+on+pulmonary+function+in+rats.">Effects of the Clara cell toxin, 4-ipomeanol, on pulmonary function in rats.</a> J Appl Physiol. 54 (2), 337-344 (1983).</li><li>Depledge, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Respiration+and+lung+function+in+the+mouse,+Mus+musculus+(with+a+note+on+mass+exponents+and+respiratory+variables).">Respiration and lung function in the mouse, Mus musculus (with a note on mass exponents and respiratory variables).</a> Respir Physiol. 60 (1), 83-94 (1985).</li><li>Depledge, M. H., Collis, C. H., Barrett, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+technique+for+measuring+carbon+monoxide+uptake+in+mice.">A technique for measuring carbon monoxide uptake in mice.</a> Int J Radiat Oncol Biol Phys. 7 (4), 485-489 (1981).</li><li>Fallica, J., Das, S., Horton, M. R., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+Carbon+Monoxide+Diffusing+Capacity+in+the+Mouse+Lung.">Application of Carbon Monoxide Diffusing Capacity in the Mouse Lung.</a> J Appl Physiol. 110 (5), 1455-1459 (2011).</li><li>Chaudhary, N., Datta, K., Askin, F. B., Staab, J. F., Marr, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cystic+fibrosis+transmembrane+conductance+regulator+regulates+epithelial+cell+response+to+Aspergillus+and+resultant+pulmonary+inflammation.">Cystic fibrosis transmembrane conductance regulator regulates epithelial cell response to Aspergillus and resultant pulmonary inflammation.</a> Am J Respir Crit Care Med. 185 (3), 301-310 (2012).</li><li>Foster, W. M., Walters, D. M., Longphre, M., Macri, K., Miller, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methodology+for+the+measurement+of+mucociliary+function+in+the+mouse+by+scintigraphy.">Methodology for the measurement of mucociliary function in the mouse by scintigraphy.</a> J Appl Physiol. 90 (3), 1111-1117 (2001).</li><li>Yildirim, A. O., 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=Palifermin+induces+alveolar+maintenance+programs+in+emphysematous+mice.">Palifermin induces alveolar maintenance programs in emphysematous mice.</a> Am J Respir Crit Care Med. 181 (7), 705-717 (2010).</li><li>Collins, S. L., Chan-Li, Y., Hallowell, R. W., Powell, J. D., Horton, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+vaccination+as+a+novel+treatment+for+lung+fibrosis.">Pulmonary vaccination as a novel treatment for lung fibrosis.</a> PLoS One. 7 (2), e31299 (2012).</li><li>Alessio, F. 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=CD4+CD25+Foxp3++Tregs+resolve+experimental+lung+injury+in+mice+and+are+present+in+humans+with+acute+lung+injury.">CD4+CD25+Foxp3+ Tregs resolve experimental lung injury in mice and are present in humans with acute lung injury.</a> J Clin Invest. 119 (10), 2898-2913 (2009).</li><li>Martinez, F. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+clinical+course+of+patients+with+idiopathic+pulmonary+fibrosis.">The clinical course of patients with idiopathic pulmonary fibrosis.</a> Ann Intern Med. 142 (12 Pt 1), 963-967 (2005).</li><li>Zhou, L., 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=Correction+of+lethal+intestinal+defect+in+a+mouse+model+of+cystic+fibrosis+by+human+CFTR.">Correction of lethal intestinal defect in a mouse model of cystic fibrosis by human CFTR.</a> Science. 266 (5191), 1705-1708 (1994).</li></ol>

Não há conflitos de interesse, e nada a divulgar.

No presente trabalho, definimos uma nova métrica para quantificar a capacidade trocas gasosas do pulmão do rato. Esta métrica é análoga à capacidade de difusão, uma medida clínica comum que mede a função primária do pulmão, isto é, a sua capacidade para a troca de gás. A capacidade de difusão é a única medida funcional do pulmão que podem ser facilmente e rapidamente feito em ambos os ratos e os seres humanos. Para a detecção da doença de pulmão em camundongos, um objectivo importante é quantifica...

O mouse é agora o animal primário usado para modelar uma variedade de doenças pulmonares. Para estudar os mecanismos que underly tais patologias, são necessários métodos fenotípicos que podem quantificar a que as alterações patológicas. Embora existam muitos estudos com ratos, onde ventilação mecânica são medidos, essas medidas são geralmente relacionado com as avaliações padrão da função pulmonar normalmente feitos em seres humanos. Isso é lamentável, uma vez que a capacidade de executar as medidas equivalentes em camundongos e seres humanos podem facilitar a tradução dos resultados em modelos de ratos para doenças humanas. Uma das medidas mais comuns e facilmente feitas em seres humanos é a capacidade de difusão do monóxido de carbono (DLCO) 1,2, mas esta medida só foi raramente feito em modelos de ratos. Nesses estudos, onde foi relatado 3-7, não houve estudos de acompanhamento, em parte porque os procedimentos são frequentemente onerosos ou pode reqùire equipamentos complexos. Outra abordagem é a utilização de um método de CO reinalatório em um sistema de estado estacionário, o que tem a vantagem de ser capaz de medir a difusão de CO em ratos conscientes. No entanto, este método é muito complicado, e os resultados podem variar de acordo com o nível de ventilação do rato bem como de O 2 e CO 2 concentrações de 8,9. Essas dificuldades parecem ter impedido o uso rotineiro de capacidade de detectar patologias pulmonares em ratos difusão, apesar de suas várias vantagens. Para contornar os problemas com a medição da capacidade de difusão em camundongos, os detalhes de um meio simples para medi-lo em camundongos têm sido relatados recentemente 10. O procedimento elimina o difícil problema de amostragem de gás alveolar não contaminada por amostragem rapidamente um volume igual a todo o gás inspirado. Este procedimento resulta em uma medida muito reprodutível, o denominado factor de difusão para o monóxido de carbono (Dfco), que é sensível a uma série de pathologic alterações no fenótipo pulmonar. O Dfco é portanto calculada como 1 - (CO 9 / CO c) / (Ne 9 / Ne c), onde a e c 9 subscritos referem-se a concentrações de gases de calibração injectados e os gases eliminados após um tempo de 9 s apneia, respectivamente. Dfco é uma variável adimensional, o qual varia entre 0 e 1, com 1 reflectindo a absorção completa de todo o CO, e 0 reflectindo qualquer absorção de CO. Nesta apresentação, mostram como fazer a medição da capacidade de difusão, e como ela pode ser usada para documentar as alterações em quase todos os modelos existentes doença do pulmão do rato, incluindo enfisema, fibrose, lesão pulmonar aguda, e infecções virais e fúngicas.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Gas Chromatograph</td>
			<td>Inficon</td>
			<td>Micro GC Model 3000A</td>
			<td>Agilent makes a comparable model</td>
		</tr>
		<tr>
			<td>18 g Luer stub needle</td>
			<td>Becton Dickenson</td>
			<td></td>
			<td>Several other possible vendors</td>
		</tr>
		<tr>
			<td>3 mL plastic syringe</td>
			<td>Becton Dickenson</td>
			<td></td>
			<td>Several other possible vendors</td>
		</tr>
		<tr>
			<td>Polypropylene gas sample bags</td>
			<td>SKC</td>
			<td>1 or 2 liter capacity works well</td>
			<td>Other gas tight bags will work well</td>
		</tr>
		<tr>
			<td>Gas tank, 0.3% Ne,0.3% CO, balance air; (size ME)</td>
			<td>Airgas, Inc</td>
			<td>Z04 NI785ME3012</td>
			<td>This is the standard mixture used for DLCO in humans</td>
		</tr>
		<tr>
			<td>25 TCID50/mouse of influenza virus A/PR8 diluted in phosphate buffered saline.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Porcine pancreatic elastase</td>
			<td>Elastin Products, Owensville, MO</td>
			<td></td>
			<td>5.4 U</td>
		</tr>
		<tr>
			<td>Bleomycin</td>
			<td>APP Pharmaceuticals, Schaumburg, IL</td>
			<td></td>
			<td>0.25 U</td>
		</tr>
		<tr>
			<td>Escherichia coli LPS8</td>
			<td>Sigma L2880</td>
			<td></td>
			<td>3 &#956;g/g body weight; O55:B5</td>
		</tr>
		<tr>
			<td>Aspergillus fumigatus (isolate Af293) conidia were collected from mature colonies grown on potato dextrose agar.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

phenotyping mouse pulmonary function in vivo with the lung diffusing capacity

O mouse é agora o animal primário usado para modelar uma variedade de doenças pulmonares. Para estudar os mecanismos que estão por trás dessas patologias, são necessários métodos fenotípicos que podem quantificar as alterações patológicas. Além disso, para proporcionar relevância translacional para os modelos de ratinho, tais medições devem ser testes que podem ser facilmente feitos em ambos os seres humanos e ratinhos. Infelizmente, no presente literatura algumas medições fenotípicas da função do pulmão têm aplicação directa em seres humanos. Uma exceção é a capacidade de difusão do monóxido de carbono, que é uma medida que é feito rotineiramente em seres humanos. No presente relatório, nós descrevemos um meio para medir rapidamente e simplesmente esta capacidade de difusão em camundongos. O procedimento envolve a inflação pulmonar breve com gases marcadores num rato anestesiado, seguido por um 1 min de tempo de análise de gás. Nós testamos a capacidade deste método para detectar várias patologias pulmonares, incluindo enfisema, fibrose, lesão pulmonar aguda e gripe einfecções pulmonares fúngicas, bem como a maturação pulmonar monitoramento em filhotes jovens. Os resultados mostram uma diminuição significativa em todas as patologias pulmonares, bem como um aumento da capacidade de difusão com a maturação pulmonar. Esta medida da capacidade de difusão pulmonar, portanto, fornece um teste de função pulmonar, que tem ampla aplicação com a sua capacidade de detectar mudanças estruturais fenotípicas com a maioria dos modelos de pulmão patológicas existentes.

A Figura 1 mostra as medições Dfco dos ratos adultos em grupos A, B, C, D, E e F. Houve uma redução significante com ambas as infecções por Aspergillus e da gripe, bem como diminuições significativas na fibrótica, enfisema, e aguda modelos de lesão do pulmão. A Figura 2 mostra as alterações do Grupo G de desenvolvimento em Dfco ao longo do tempo como a idade ratinhos 2-6 semanas. Houve um ligeiro mas significativo aumento no desenvolvimento pulmonar ao longo deste curso de ...

Watch this Scientific Journal Video about Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity at JoVE.com

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

We describe a means to quickly and simply measure the lung diffusing capacity in mice and show that it is sufficiently sensitive to phenotype changes in multiple common lung pathologies. This metric thus brings direct translational relevance to the mouse models, since diffusing capacity is also easily measured in humans.

Função Pulmonar Fenotipagem Rato<em&gt; In Vivo</em&gt; Com a capacidade pulmonar Diffusing

The mouse is now the primary animal used to model a variety of lung diseases. To study the mechanisms that underlie such pathologies, phenotypic methods ...

phenotyping-mouse-pulmonary-function-vivo-with-lung-diffusing

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JoVE Journal

Biology

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

10.5K visualizações.  Johns Hopkins University Bloomberg School of Public Health. We describe a means to quickly and simply measure the lung diffusing capacity in mice and show that it is sufficiently sensitive to phenotype changes in multiple common lung pathologies. This metric thus brings direct translational relevance to the mouse models, since diffusing capacity is also easily measured in humans.

Vídeo: Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

In vivo de imagens e tratamentos terapêuticos em um modelo de camundongo ortotópico de câncer de ovário

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Biologia

Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow

The isolated, ventilated and instrumented mouse lung preparation allows steady and pulsatile pulmonary vascular pressure-flow relationships to be measured with independent control over pulmonary arterial flow rate, flow rate waveform, airway pressure and left atrial pressure. Pulmonary vascular resistance is calculated based on multi-point, steady pressure-flow curves; pulmonary vascular impedance is calculated from pulsatile pressure-flow curves obtained at a range of frequencies. As now recognized clinically, impedance is a superior measure of right ventricular afterload than resistance because it includes the effects of vascular compliance, which are not negligible, especially in the pulmonary circulation. Three important metrics of impedance - the zero hertz impedance Z0, the characteristic impedance ZC, and the index of wave reflection RW - provide insight into distal arterial cross-sectional area available for flow, proximal arterial stiffness and the upstream-downstream impedance mismatch, respectively. All results obtained in isolated, ventilated and perfused lungs are independent of sympathetic nervous system tone, volume status and the effects of anesthesia. We have used this technique to quantify the impact of pulmonary emboli and chronic hypoxia on resistance and impedance, and to differentiate between sites of action (i.e., proximal vs. distal) of vasoactive agents and disease using the pressure dependency of ZC. Furthermore, when these techniques are used with the lungs of genetically engineered strains of mice, the effects of molecular-level defects on pulmonary vascular structure and function can be determined.

The following protocol outlines the process of isolating, ventilating and instrumenting mouse lungs to measure steady or pulsatile pulmonary vascular pressure-flow relationships in order to quantify the effects of blood flow, airflow, airway changes and vascular changes on right ventricular afterload.

Caracterização do isolado, ventilado, Lung Mouse e Instrumentados perfundidos com fluxo pulsátil

The isolated, ventilated and instrumented mouse lung preparation allows steady and pulsatile pulmonary vascular pressure-flow relationships to be measured ...

Examining BCL-2 Family Function with Large Unilamellar Vesicles

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate apoptosis1. Following cellular stress (e.g., DNA damage), the pro-apoptotic BCL-2 family effectors BAK (BCL-2 antagonistic killer 1) and/or BAX (BCL-2 associated X protein) become activated and compromise the integrity of the outer mitochondrial membrane (OMM), though the process referred to as mitochondrial outer membrane permeabilization (MOMP)1. After MOMP occurs, pro-apoptotic proteins (e.g., cytochrome c) gain access to the cytoplasm, promote caspase activation, and apoptosis rapidly ensues2.
In order for BAK/BAX to induce MOMP, they require transient interactions with members of another pro-apoptotic subset of the BCL-2 family, the BCL-2 homology domain 3 (BH3)-only proteins, such as BID (BH3-interacting domain agonist)3-6. Anti-apoptotic BCL-2 family proteins (e.g., BCL-2 related gene, long isoform, BCL-xL; myeloid cell leukemia 1, MCL-1) regulate cellular survival by tightly controlling the interactions between BAK/BAX and the BH3-only proteins capable of directly inducing BAK/BAX activation7,8. In addition, anti-apoptotic BCL-2 protein availability is also dictated by sensitizer/de-repressor BH3-only proteins, such as BAD (BCL-2 antagonist of cell death) or PUMA (p53 upregulated modulator of apoptosis), which bind and inhibit anti-apoptotic members7,9. As most of the anti-apoptotic BCL-2 repertoire is localized to the OMM, the cellular decision to maintain survival or induce MOMP is dictated by multiple BCL-2 family interactions at this membrane.
 Large unilamellar vesicles (LUVs) are a biochemical model to explore relationships between BCL-2 family interactions and membrane permeabilization10. LUVs are comprised of defined lipids that are assembled in ratios identified in lipid composition studies from solvent extracted Xenopus mitochondria (46.5% phosphatidylcholine, 28.5% phosphatidylethanoloamine, 9% phosphatidylinositol, 9% phosphatidylserine, and 7% cardiolipin)10. This is a convenient model system to directly explore BCL-2 family function because the protein and lipid components are completely defined and tractable, which is not always the case with primary mitochondria. While cardiolipin is not usually this high throughout the OMM, this model does faithfully mimic the OMM to promote BCL-2 family function. Furthermore, a more recent modification of the above protocol allows for kinetic analyses of protein interactions and real-time measurements of membrane permeabilization, which is based on LUVs containing a polyanionic dye (ANTS: 8-aminonaphthalene-1,3,6-trisulfonic acid) and cationic quencher (DPX: p-xylene-bis-pyridinium bromide)11. As the LUVs permeabilize, ANTS and DPX diffuse apart, and a gain in fluorescence is detected. Here, commonly used recombinant BCL-2 family protein combinations and controls using the LUVs containing ANTS/DPX are described.

Biochemically-defined large unilamellar vesicles (LUVs) are a convenient model system to analyze BCL-2 family interactions with immediate implications in better understanding the mitochondrial pathway of apoptosis. A method to produce LUVs, along with standard BCL-2 family protein combinations and controls to examine LUV permeabilization, are presented.

Examinando BCL-2 Função Família com grandes vesículas unilamelares

The BCL-2 (B cell CLL/Lymphoma) family is comprised of approximately twenty proteins that collaborate to either maintain cell survival or initiate ...

Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. 
Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. 
In vitro models of differentiated human nasal epithelial cells will enable investigators to address novel and important research questions by using organotypic experimental models that largely mimic the nasal epithelium in vivo.

Nasal epithelial cells, obtained through superficial scrape biopsy of human volunteers, are expanded and transferred onto tissue culture inserts. Upon reaching confluency, cells are grown at air liquid interface, yielding cultures of ciliated and non-ciliated cells. Differentiated nasal epithelial cell cultures provide viable experimental models for studying the respiratory mucosa.

A cultura de células epiteliais nasais Humano na interface ar líquido

In vitro models using human primary  epithelial cells are essential in understanding key functions of the respiratory  epithelium in the context of ...

Assessment of Calcium Sparks in Intact Skeletal Muscle Fibers

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in the striated muscle fibers that appear as highly localized Ca2+ release events mediated by ryanodine receptor (RyR) Ca2+ release channels on the sarcoplasmic reticulum (SR) membrane. Proper assessment of muscle Ca2+ sparks could provide information on the intracellular Ca2+&#160;handling properties of healthy and diseased striated muscles. Although Ca2+ sparks events are commonly seen in resting cardiomyocytes, they are rarely observed in resting skeletal muscle fibers; thus there is a need for methods to generate and analyze sparks in skeletal muscle fibers.
Detailed here is an experimental protocol for measuring Ca2+ sparks in isolated flexor digitorm brevis (FDB) muscle fibers using fluorescent Ca2+ indictors and laser scanning confocal microscopy. In this approach, isolated FDB fibers are exposed to transient hypoosmotic stress followed by a return to isotonic physiological solution. Under these conditions, a robust Ca2+ sparks response is detected adjacent to the sarcolemmal membrane in young healthy FDB muscle fibers. Altered Ca2+ sparks response is detected in dystrophic or aged skeletal muscle fibers. This approach has recently demonstrated that membrane-delimited signaling involving cross-talk between inositol (1,4,5)-triphosphate receptor (IP3R) and RyR contributes to Ca2+ spark activation in skeletal muscle. In summary, our studies using osmotic stress induced Ca2+ sparks showed that this intracellular response reflects a muscle signaling mechanism in physiology and aging/disease states, including mouse models of muscle dystrophy (mdx mice) or amyotrophic lateral sclerosis (ALS model).

Described here is a method to directly measure calcium sparks, the elementary units of Ca2+ release from sarcoplasmic reticulum&#160;in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca2+ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca2+ signaling can be employed to assess muscle function in health and disease.

Avaliação do cálcio Faíscas intactas fibras musculares esqueléticas

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in ...

Isolation of Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High Throughput Microplate Respiratory Measurements

Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes. Mitochondrial respirometric assays from isolated mitochondrial preparations allow for the assessment of mitochondrial function, as well as determination of the mechanism(s) of action of drugs and proteins that modulate metabolism. Current isolation procedures often require large quantities of tissue to yield high quality mitochondria necessary for respirometric assays. The methods presented herein describe how high quality purified mitochondria (~ 450 &#181;g) can be isolated from minimal quantities (~75-100 mg) of mouse skeletal muscle for use in high throughput respiratory measurements. We determined that our isolation method yields 92.5&#177; 2.0% intact mitochondria by measuring citrate synthase activity spectrophotometrically. In addition, Western blot analysis in isolated mitochondria resulted in the faint expression of the cytosolic protein, GAPDH, and the robust expression of the mitochondrial protein, COXIV. The absence of a prominent GAPDH band in the isolated mitochondria is indicative of little contamination from non-mitochondrial sources during the isolation procedure. Most importantly, the measurement of O2 consumption rate with micro-plate based technology and determining the respiratory control ratio (RCR) for coupled respirometric assays shows highly coupled (RCR; &#62;6 for all assays) and functional mitochondria. In conclusion, the addition of a separate mincing step and significantly reducing motor driven homogenization speed of a previously reported method has allowed the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle that results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.

Here, we present a modification of a previously reported method that allows for the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle. This procedure results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.

Isolamento de mitocôndrias de quantidades mínimas de Rato Músculo Esquelético para medições High Throughput Microplate respiratórias

Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes. Mitochondrial ...

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, is expressed in neurons in response to various stimuli. The protein product can be readily detected with immunohistochemical techniques leading to the use of c-FOS detection to map groups of neurons that display changes in their activity. In this article, we focused on the identification of brainstem neuronal populations involved in the ventilatory adaptation to hypoxia or hypercapnia. Two approaches were described to identify involved neuronal populations in vivo in animals and ex vivo in deafferented brainstem preparations. In vivo, animals were exposed to hypercapnic or hypoxic gas mixtures. Ex vivo, deafferented preparations were superfused with hypoxic or hypercapnic artificial cerebrospinal fluid. In both cases, either control in vivo animals or ex vivo preparations were maintained under normoxic and normocapnic conditions. The comparison of these two approaches allows the determination of the origin of the neuronal activation i.e., peripheral and/or central. In vivo and ex vivo, brainstems were collected, fixed, and sliced into sections. Once sections were prepared, immunohistochemical detection of the c-FOS protein was made in order to identify the brainstem groups of cells activated by hypoxic or hypercapnic stimulations. Labeled cells were counted in brainstem respiratory structures. In comparison to the control condition, hypoxia or hypercapnia increased the number of c-FOS labeled cells in several specific brainstem sites that are thus constitutive of the neuronal pathways involved in the adaptation of the central respiratory drive.

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo.

A proteína c-Fos Detecção imuno: Uma ferramenta útil como um marcador de vias centrais envolvidos em respostas fisiológicas específicas<em&gt; In Vivo</em&gt; e<em&gt; Ex Vivo</em

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, ...

In Vivo Study of Human Endothelial-Pericyte Interaction Using the Matrix Gel Plug Assay in Mouse

Angiogenesis is the process by which new blood vessels are formed from existing vessels. New vessel growth requires coordinated endothelial cell proliferation, migration, and alignment to form tubular structures followed by recruitment of pericytes to provide mural support and facilitate vessel maturation. Current in vitro cell culture approaches cannot fully reproduce the complex biological environment where endothelial cells and pericytes interact to produce functional vessels. We present a novel application of the in vivo matrix gel plug assay to study endothelial-pericyte interactions and formation of functional blood vessels using severe combined immune deficiency mutation (SCID) mice. Briefly, matrix gel is mixed with a solution containing endothelial cells with or without pericytes followed by injection into the back of anesthetized SCID mice. After 14 days, the matrix gel plugs are removed, fixed and sectioned for histological analysis. The length, number, size and extent of pericyte coverage of mature vessels (defined by the presence of red blood cells in the lumen) can be quantified and compared between experimental groups using commercial statistical platforms. Beyond its use as an angiogenesis assay, this matrix gel plug assay can be used to conduct genetic studies and as a platform for drug discovery. In conclusion, this protocol will allow researchers to complement available in vitro assays for the study of endothelial-pericyte interactions and their relevance to either systemic or pulmonary angiogenesis.

In Vivo Study of Human Endothelial-Pericyte Interaction Using the Matrix Gel Plug Assay in Mouse

We present a protocol to study human endothelial-pericyte interactions in mouse using a variation of the matrix gel plug angiogenesis assay.

No estudo in vivo da Human Interaction Endotelial-pericyte usando o plug Ensaio Matrix Gel no mouse

Angiogenesis is the process by which new blood vessels are formed from existing vessels. New vessel growth requires coordinated endothelial cell ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

Medindo a rigidez<em&gt; Ex Vivo</em&gt; Mouse aortas Usando Microscopia de Força Atômica

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

Induction of Right Ventricular Failure by Pulmonary Artery Constriction and Evaluation of Right Ventricular Function in Mice

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of RVF. Previous rat models imitating RVF progression have been described. Compared with rats, mice are more accessible, economical, and widely used in animal experiments. We developed a pulmonary artery constriction (PAC) approach which is comprised of banding the pulmonary trunk in mice to induce right ventricular (RV) hypertrophy. A special surgical latch needle was designed that allows for easier separation of the aorta and the pulmonary trunk. In our experiments, the use of this fabricated latch needle reduced the risk of arteriorrhexis and improved the surgical success rate to 90%. We used different padding needle diameters to precisely create quantitative constriction, which can induce different degrees of RV hypertrophy. We quantified the degree of constriction by evaluating the blood flow velocity of the PA, which was measured by noninvasive transthoracic echocardiography. RV function was precisely evaluated by right heart catheterization at 8 weeks after surgery. The surgical instruments made inhouse were composed of common materials using a simple process that is easy to master. Therefore, the PAC approach described here is easy to imitate using instruments made in the lab and can be widely used in other labs. This study presents a modified PAC approach that has a higher success rate than other models and an 8-week postsurgery survival rate of 97.8%. This PAC approach provides a useful technique for studying the mechanism of RVF and will enable an increased understanding of RVF.

Here, we provide a useful approach for studying the mechanism of right ventricular failure. A more convenient and efficient approach to pulmonary artery constriction is established using surgical instruments made inhouse. In addition, methods to evaluate the quality of this approach by echocardiography and catheterization are provided.

Indução de insuficiência ventricular direita por constrição da artéria pulmonar e avaliação da função ventricular direita em camundongos

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of ...