Surface Fluorescence Studies of Tissue Mitochondrial Redox State in Isolated Perfused Rat Lungs

We designed a fiber-optic-based optoelectronic fluorometer to measure emitted fluorescence from the auto-fluorescent electron carriers NADH and FAD of the mitochondrial electron transport chain (ETC). The ratio of NADH to FAD is called the redox ratio (RR = NADH/FAD) and is an indicator of the oxidoreductive state of tissue. We evaluated the fluorometer by measuring the fluorescence intensities of NADH and FAD at the surface of isolated, perfused rat lungs. Alterations of lung mitochondrial metabolic state were achieved by the addition of rotenone (complex I inhibitor), potassium cyanide (KCN, complex IV inhibitor) and/or pentachlorophenol (PCP, uncoupler) into the perfusate recirculating through the lung. Rotenone- or KCN-containing perfusate increased RR by 21 and 30%, respectively. In contrast, PCP-containing perfusate decreased RR by 27%. These changes are consistent with the established effects of rotenone, KCN, and PCP on the redox status of the ETC. Addition of blood to perfusate quenched NADH and FAD signal, but had no effect on RR. This study demonstrates the capacity of fluorometry to detect a change in mitochondrial redox state in isolated perfused lungs, and suggests the potential of fluorometry for use in in vivo experiments to extract a sensitive measure of lung tissue health in real-time

Fazer política desde a escola: narrativas biográficas de jovens militantes estudantis na Argentina do Bicentenário

Este artículo trata sobre el papel de la escuela en el encuentro de los y las jóvenes con la política en la Argentina de los años siguientes al Bicentenario (2010). Presentamos narrativas de militantes de distintos espacios políticos, con el objetivo de indagar el rol que asignan a la escuela en sus trayectorias, desde las perspectivas de la socialización y la subjetivación política, con sustento en aportes de la sociología de la individuación. Tomamos para ello sus argumentaciones expuestas en dos debates grupales realizados en 2012 y 2013, en torno a temas clave de la agenda juvenil: la memoria estudiantil de la última dictadura cívico-militar, condensada en el relato de “La noche de los lápices”, y la ampliación del voto a los 16 años de edad, promulgada por ley en 2012.This article is about the role of school in young people's interactions with politics in Argentina following the country's bicentennial year (2010). The authors present narratives of young activists from different political spaces with the aim of investigating the role that school has had in their trajectories, with a particular focus on their socialization and political subjectivation, incorporating contributions from the Sociology of Individuation. For this purpose, the authors take the arguments that were presented in two group discussions in 2012 and 2013 regarding two key issues for the youth agenda: student memory of the most recent civic-military dictatorship, condensed in the story titled "The Night of the Pencils", and the change in legislation so that young people aged 16 and older can vote in elections, which was passed in 2012.Este artigo é sobre o papel da escola no encontro dos jovens com a política na Argentina após o ano do bicentenário (2010). Apresentam-se narrativas de jovens ativistas de diferentes espaços políticos, com o objetivo de investigar o papel atribuído a escola nas suas trajetórias desde as perspectivas da socialização e subjetivação política, com contribuições da sociologia da individuaãção. Tomamos portanto os argumentos que apresentaram-se em duas discussões grupais em 2012 e 2013, sobre duas questões chave da agenda da juventude: a memória estudantil da última ditadura cívico-militar, condensada na história de "A noite dos lápis", e a extensão do voto a 16 anos de idade, criado por lei em 2012.Fil: Kriger, Miriam Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Sociales. Instituto de Desarrollo Económico y Social. Centro de Investigaciones Sociales; ArgentinaFil: Said, Shirly Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Sociales. Instituto de Desarrollo Económico y Social. Centro de Investigaciones Sociales; Argentin

In vivo Detection of Hyperoxia-induced Pulmonary Endothelial Cell Death Using \u3csup\u3e99m\u3c/sup\u3eTc-Duramycin

Introduction 99mTc-duramycin, DU, is a SPECT biomarker of tissue injury identifying cell death. The objective of this study is to investigate the potential of DU imaging to quantify capillary endothelial cell death in rat lung injury resulting from hyperoxia exposure as a model of acute lung injury. Methods Rats were exposed to room air (normoxic) or \u3e 98% O2 for 48 or 60 hours. DU was injected i.v. in anesthetized rats, scintigraphy images were acquired at steady-state, and lung DU uptake was quantified from the images. Post-mortem, the lungs were removed for histological studies. Sequential lung sections were immunostained for caspase activation and endothelial and epithelial cells. Results Lung DU uptake increased significantly (p \u3c 0.001) by 39% and 146% in 48-hr and 60-hr exposed rats, respectively, compared to normoxic rats. There was strong correlation (r2 = 0.82, p = 0.005) between lung DU uptake and the number of cleaved caspase 3 (CC3) positive cells, and endothelial cells accounted for more than 50% of CC3 positive cells in the hyperoxic lungs. Histology revealed preserved lung morphology through 48 hours. By 60 hours there was evidence of edema, and modest neutrophilic infiltrate. Conclusions Rat lung DU uptake in vivo increased after just 48 hours of \u3e 98% O2 exposure, prior to the onset of any substantial evidence of lung injury. These results suggest that apoptotic endothelial cells are the primary contributors to the enhanced DU lung uptake, and support the utility of DU imaging for detecting early endothelial cell death in vivo

Hypoxia Preconditioning Increases Survival and Decreases Expression of Toll-like Receptor 4 in Pulmonary Artery Endothelial Cells Exposed to Lipopolysaccharide

Pulmonary or systemic infections and hypoxemic respiratory failure are among the leading causes of admission to intensive care units, and these conditions frequently exist in sequence or in tandem. Inflammatory responses to infections are reproduced by lipopolysaccharide (LPS) engaging Toll-like receptor 4 (TLR4). Apoptosis is a hallmark of lung injury in sepsis. This study was conducted to determine whether preexposure to LPS or hypoxia modulated the survival of pulmonary artery endothelial cells (PAECs). We also investigated the role TLR4 receptor expression plays in apoptosis due to these conditions. Bovine PAECs were cultured in hypoxic or normoxic environments and treated with LPS. TLR4 antagonist TAK-242 was used to probe the role played by TLR4 receptors in cell survival. Cell apoptosis and survival were measured by caspase 3 activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) incorporation. TLR4 expression and tumor necrosis factor α (TNF-α) production were also determined. LPS increased caspase 3 activity in a TAK-242-sensitive manner and decreased MTT incorporation. Apoptosis was decreased in PAECs preconditioned with hypoxia prior to LPS exposure. LPS increased TNF-α production, and hypoxic preconditioning blunted it. Hypoxic preconditioning reduced LPS-induced TLR4 messenger RNA and TLR4 protein. TAK-242 decreased to baseline the LPS-stimulated expression of TLR4 messenger RNA regardless of environmental conditions. In contrast, LPS followed by hypoxia substantially increased apoptosis and cell death. In conclusion, protection from LPS-stimulated PAEC apoptosis by hypoxic preconditioning is attributable in part to reduction in TLR4 expression. If these signaling pathways apply to septic patients, they may account for differing sensitivities of individuals to acute lung injury depending on oxygen tensions in PAECs in vivo

Protection by Inhaled Hydrogen Therapy in a Rat Model of Acute Lung Injury can be Tracked \u3cem\u3ein vivo\u3c/em\u3e Using Molecular Imaging

Inhaled hydrogen gas (H2) provides protection in rat models of human acute lung injury (ALI). We previously reported that biomarker imaging can detect oxidative stress and endothelial cell death in vivo in a rat model of ALI. Our objective was to evaluate the ability of 99mTc-hexamethylpropyleneamineoxime (HMPAO) and 99mTc-duramycin to track the effectiveness of H2 therapy in vivo in the hyperoxia rat model of ALI. Rats were exposed to room air (normoxia), 98% O2 + 2% N2 (hyperoxia) or 98% O2 + 2% H2 (hyperoxia+H2) for up to 60 h. In vivo scintigraphy images were acquired following injection of 99mTc-HMPAO or 99mTc-duramycin. For hyperoxiarats, 99mTc-HMPAO and 99mTc-duramycin lung uptake increased in a time-dependent manner, reaching a maximum increase of 270% and 150% at 60 h, respectively. These increases were reduced to 120% and 70%, respectively, in hyperoxia+H2 rats. Hyperoxia exposure increased glutathione content in lung homogenate (36%) more than hyperoxia+H2 (21%), consistent with increases measured in 99mTc-HMPAO lung uptake. In 60-h hyperoxia rats, pleural effusion, which was undetectable in normoxia rats, averaged 9.3 gram/rat, and lung tissue 3-nitrotyrosine expression increased by 790%. Increases were reduced by 69% and 59%, respectively, in 60-h hyperoxia+H2 rats. This study detects and tracks the anti-oxidant and anti-apoptotic properties of H2 therapy in vivo after as early as 24 h of hyperoxia exposure. The results suggest the potential utility of these SPECT biomarkers for in vivo assessment of key cellular pathways in the pathogenesis of ALI and for monitoring responses to therapies

All Work or All Play? The Impact of Cultural and Clinical Activities on Perceived Cultural Sensitivity Development During an Occupational Therapy Service Learning Experience

International service learning experiences provide invaluable opportunities for occupational therapy practitioners and students to practice clinical skills while also being exposed to different cultures and experiences not available in their home country. Studies have shown that clinical activities during international service learning experiences increase students’ cultural awareness and sensitivity, however the effect of cultural activities on students’ development is not known. Over the span of two years, multiple groups of American occupational therapy students traveled to Morocco for a ten day service learning experience and served in a variety of clinical activities across the lifespan and population. Students also participated in cultural and tourist activities for increased exposure to the local culture. This study explored the development of cultural sensitivity through participation in both clinical and cultural activities during the international service learning experience through a quantitative survey (n=22) and qualitative interview (n=17). Participants indicated that both clinical and cultural activities played a role in their self-perceived development of cultural sensitivity on the quantitative survey. Themes identified within the qualitative interview revealed the impactful qualities of various activities, identified as “Authenticity,” “Communication Skills,” “Role of Religion,” and “Exposure to Morocco.” It appears that both kinds of activities play a role in development of cultural sensitivity, and regardless of the activity, authenticity and exposure to the culture along with opportunities to practice communication skills play the largest role in students perceiving a personal increase in cultural awareness and sensitivity while participating in international service learning experiences

Biomarkers for Radiation Pneumonitis Using Noninvasive Molecular Imaging

Our goal is to develop minimally invasive biomarkers for predicting radiation-induced lung injury before symptoms develop. Currently, there are no biomarkers that can predict radiation pneumonitis. Radiation damage to the whole lung is a serious risk in nuclear accidents or in radiologic terrorism. Our previous studies have shown that a single dose of 15 Gy of x-rays to the thorax causes severe pneumonitis in rats by 6–8 wk. We have also developed a mitigator for radiation pneumonitis and fibrosis that can be started as late as 5 wk after radiation. Methods: We used 2 functional SPECT probes in vivo in irradiated rat lungs. Regional pulmonary perfusion was measured by injection of 99mTc-macroaggregated albumin. Perfused volume was determined by comparing the volume of distribution of 99mTc-macroaggregated albumin to the anatomic lung volume obtained by small-animal CT. A second probe, 99mTc-labeled Duramycin, which binds to apoptotic cells, was used to measure pulmonary cell death in the same rat model. Results: The perfused volume of lung was decreased by about 25% at 1, 2, and 3 wk after receipt of 15 Gy, and 99mTc-Duramycin uptake was more than doubled at 2 and 3 wk. There was no change in body weight, breathing rate, or lung histology between irradiated and nonirradiated rats at these times. Pulmonary vascular resistance and vascular permeability measured in isolated perfused lungs ex vivo increased at 2 wk after 15 Gy of irradiation. Conclusion: Our results suggest that SPECT biomarkers have the potential to predict radiation injury to the lungs before substantial functional or histologic damage is observed. Early prediction of radiation pneumonitis in time to initiate mitigation will benefit those exposed to radiation in the context of therapy, accidents, or terrorism

Lung Injury Pathways: Adenosine Receptor 2B Signaling Limits Development of Ischemic Bronchiolitis Obliterans Organizing Pneumonia

Purpose/Aim of the Study: Adenosine signaling was studied in bronchiolitis obliterans organizing pneumonia (BOOP) resulting from unilateral lung ischemia. Materials and Methods: Ischemia was achieved by either left main pulmonary artery or complete hilar ligation. Sprague–Dawley (SD) rats, Dahl salt sensitive (SS) rats and SS mutant rat strains containing a mutation in the A2B adenosine receptor gene (Adora2b) were studied. Adenosine concentrations were measured in bronchoalveolar lavage (BAL) by HPLC. A2A (A2AAR) and A2B adenosine receptor (A2BAR) mRNA and protein were quantified. Results: Twenty-four hours after unilateral PA ligation, BAL adenosine concentrations from ischemic lungs were increased relative to contralateral lungs in SD rats. A2BAR mRNA and protein concentrations were increased after PA ligation while miR27a, a negatively regulating microRNA, was decreased in ischemic lungs. A2AAR mRNA and protein concentrations remained unchanged following ischemia. A2BAR protein was increased in PA ligated lungs of SS rats after 7 days, and 4 h after complete hilar ligation in SD rats. SS-Adora2b mutants showed a greater extent of BOOP relative to SS rats, and greater inflammatory changes. Conclusion: Increased A2BAR and adenosine following unilateral lung ischemia as well as more BOOP in A2BAR mutant rats implicate a protective role for A2BAR signaling in countering ischemic lung injury

Subjetivación política y educación popular: la noción del diálogo en Ranciére y Freire como aporte a la reflexión teórico-metodológica sobre bachilleratos populares

El artículo propone una contribución al campo de las pedagogías críticas, incorporando aportes de la filosofía política. Desde las perspectivas de Freire y Rancière, se analiza la noción de “diálogo” a fin de acuñar herramientas para la reflexión teórico-metodológica en torno a la subjetivación política de estudiantes de bachilleratos populares de Buenos Aires en la actualidad, en el marco de diversas experiencias de educación popular impulsadas por movimientos sociales latinoamericanos. Se busca relacionar la propuesta de “educación dialógica” de Freire, entendida como acto de transformación de la realidad y de formación de los sujetos que se liberarán transformándola, con el concepto de “litigio” de Rancière, definido como espacio de materialización de la interacción social, donde los sujetos se constituyen como tales políticamente en el conflicto. El análisis se centra en las experiencias de subjetivación política que promueven los bachilleratos populares, escuelas medias de jóvenes y adultos fundadas por organizaciones sociales tras el estallido de la crisis argentina del 2001. Para ello, se toman sus dos dimensiones de construcción político-pedagógica: hacia adentro del ámbito escolar, asociada a la propuesta de “educación dialógica”, y hacia afuera, en la lucha por el reconocimiento en la escena pública, cercana a la idea de “litigio”. desde principios del siglo XXI.Facultad de Periodismo y Comunicación Socia

"Tener el secundario":La prueba escolar como transición a la adultez en un Bachillerato Popular del AMBA

En este capítulo: "Tener el secundario": La prueba escolar como transición a la adultez en un Bachillerato Popular (BP) del AMBA, Shirly Said y Miriam Kriger analizan el vínculo de dos jóvenes estudiantes mujeres con la exigencia social de finalizar la escuela secundaria, y lograr la prueba escolar, desde la perspectiva de la sociología de la individuación. Este trabajo toma entrevistas realizadas en el marco de la tesis doctoral de la primer autora, dirigida por la segunda, que ambas analizan articulando miradas y perspectivas teóricas ligadas a los procesos de individuación y a la subjetivación política de los jóvenes.Fil: Said, Shirly Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Sociales. Instituto de Desarrollo Económico y Social. Centro de Investigaciones Sociales; ArgentinaFil: Kriger, Miriam Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Sociales. Instituto de Desarrollo Económico y Social. Centro de Investigaciones Sociales; Argentin