No description available.

No description available.

Zusammenfassung Viele Untersuchungen deuten darauf hin, dass das Surfaktantprotein A (SP-A) sowohl an der Regulation des Surfaktanthaushalts als auch als unspezifisches Opsonin an der Abwehr von Pathogenen in der Lunge beteiligt ist. Zahlreiche Polymorphismen kennzeichnen die Gene der Proteinuntereinheiten SP-A1 und 2. Die häufigste Aminosäuresubstitution Val50Leu befindet sich in der kollagenartigen Domäne, die an den Kollektinrezeptor der Phagozyten bindet. Weitere existieren in der an der Bindung an Lipopolysaccharide, Surfaktantbestandteile und Rezeptoren auf Pneumozyten beteiligten Kohlehydraterkennungsregion (CRD) der globulären Domäne. Träger des schwach exprimierten Wildtypallels 1a0 des SP-A2-Gens haben ein erhöhtes Risiko, am Atemnotsyndrom des Neugeborenen (RDS) zu erkranken. Bei der Alveolarproteinose akkumulieren die hydrophilen Surfaktantproteine A und D in den Alveolen. In der vorliegenden Arbeit wurde eine nested PCR zur isolierten Amplifikation beider SP-A-Gene etabliert. 31 Patienten mit Verdacht auf einen Surfaktantproteindefekt wurden auf neue Restriktionsfragmentlängenpolymorphismen (RFLP) im SP-A1-Gen untersucht. Der in einer Familie konstante NcoI-Polymorphismus 1162C>T in Codon 39 und der NdeI-Polymorphismus 3138T>C in Codon 184 wurden mit einer Allelfrequenz von etwa 11 % detektiert. Die Sequenzen der entsprechenden Allele wurden kloniert. Bei 14 Patienten mit idiopathischer Alveolarproteinose, therapierefraktärem Surfaktantmangel oder rezidivierender Pneumonie wurden die SP-A-Gene sequenziert. Der bisher nur SP-A1 zugeschriebene Aminosäureaustausch Val50Leu wurde als Substitution 1220G>C bei zwei Patienten im SP-A2-Gen nachgewiesen. Drei Patienten mit Alveolarproteinose waren homozygot für die Substitution Gln223Lys in der CRD des SP-A2. Bei einem Patienten handelte es sich möglicherweise um eine somatische Mutation der Leukozyten-DNA im Rahmen einer Leukämie mit sekundärer Alveolarproteinose. Ein anderer war heterozygoter Träger des seltenen Allels 6a4 mit der Aminosäuresubstitution Arg219Trp in der CRD des SP-A1 und hatte die Alveolarproteinose erst im Erwachsenenalter entwickelt. Der dritte war homozygoter Träger des sehr seltenen Allels 1a3 des SP-A2 und verstarb im Alter von 6 Wochen an konnataler Alveolarproteinose (CAP), ohne dass ein bekannter Defekt des SP-B- oder des GM-CSF-Rezeptorgens vorlag. Die SSCP-Analyse konnte allelische Varianten als Einzelstrangkonformationspolymorphismen unterscheiden, war jedoch als Suchtest in heterozygoten Proben zu unspezifisch. Der hohe Gehalt an Polymorphismusinformation (PIC) macht den SP-A-Genort sftp1 zu einem nützlichen Marker bei der Untersuchung der Surfaktantproteine und anderer auf Chromosom 10 lokalisierter Gene. / Abstract Many studies give evidence of the role of surfactant protein A (SP-A) in the regulation of surfactant homeostasis and the defence from pathogens in the lung by opsonisation. The genes for the two protein subunits SP-A1 and SP-A2 are characterised by numerous polymorphisms. The most frequently substituted amino acid Val50Leu is located within the collagen-like region, which is recognised by the collectin-receptor on phagocytes. Further amino acids are substituted in the globular region, which is involved into the binding to lipopolysaccharides, surfactant particles, and receptors on pneumocytes by its carbohydrate recognition domain (CRD). Individuals carrying the weakly expressed wild-type allele 1a0 of SP-A2 have an increased risk of developing the respiratory distress syndrome (RDS) of the new-born. Alveolar proteinosis is a disease with accumulation of the hydrophilic surfactant proteins SP-A and SP-D in the alveoli. In this study a nested PCR for separate amplification of the two SP-A genes has been established. 31 patients with suspected deficiency of a surfactant protein has been investigated for new restriction fragment length polymorphisms (RFLP) in the SP-A1 gene. The NcoI-polymorphism 1162C>T in codon 39, which was constantly inherited in one family, and the NdeI-polymorphism 3138T>C in codon 184 have been detected with an allele frequency of around 11 %. The DNA sequences of these alleles have been cloned. In 14 patients suffering from idiopathic alveolar proteinosis, therapy-refractory surfactant deficiency, or recurrent pneumonia the SP-A genes have been sequenced. The substituted amino acid Val50Leu, which was previously considered exclusively in SP-A1, has been detected in SP-A2 in two patients. Three patients with alveolar proteinosis proved to be homozygous for the substitution Gln223Lys within the CRD of SP-A2. One of these patients might have a somatic mutation in the DNA of his leucocytes, with alveolar proteinosis developing secondary to his leukaemia. Another one developed alveolar proteinosis as an adult and was heterozygous for the rare allele 6a4 which includes the substituted amino acid Arg219Trp in the CRD of SP-A1. The third one proved to be homozygous for the very rare allele 1a3 of SP-A2 and died at 6 weeks of age from congenital alveolar proteinosis (CAP) without having one of the known mutations responsible for this condition within the genes for surfactant protein B (SP-B) or the GM-CSF receptor protein. The allelic variants could be differentiated by single strand conformation polymorphism but the SSCP-analysis was not enough specific for the screening of heterozygous DNA. Due to its high polymorphism information content (PIC), the SP-A gene locus sftp1 is a useful genetic marker for the analysis of the surfactant proteins and other genes located on chromosome 10.

Influenzavirus (IV)-Infektionen der unteren Atemwege induzieren virale Pneumonien, die häufig in akutem Lungenversagen resultieren. Merkmale einer IV-induzierten Pneumonie sind Schädigungen des Alveolarepithels und eine Ansammlung von Ödemflüssigkeit im Alveolarraum, wodurch der Gasaustausch beeinträchtigt wird. In Abhängigkeit eines Natriumgradienten, aufgebaut durch die basolaterale Na,K-ATPase (NKA) und den apikalen epithelialen Natriumkanal (ENaC), wird unter normalen Bedingungen die Ödemflüssigkeit aus dem Alveolarraum entfernt. In Folge einer IV-Infektion werden verschiedene Membranionenkanäle dysreguliert und eine verringerte alveoläre Flüssigkeitsresorption (AFC) beobachtet. Eine IV-Infektion führt u.a. zu einer reduzierten NKA-Expression in nicht-infizierten Nachbarzellen, sowie zu einer Dislokation der NKA zur apikalen Zellmembran in infizierten Zellen. Co-Immunopräzipitationsstudien identifizierten das virale M2-Protein als NKA-Bindepartner. Mittels Mutationsanalyse konnten drei Aminosäuren im zytoplasmatischen Teil von M2 als kritisch für die NKA-Bindung identifiziert werden. Rekombinante IV mit gestörter NKA Bindung zeigten im Vergleich zu IV WT in polarisierten Calu 3 Zellen in vitro sowie in Mäusen in vivo eine verbesserte AFC. Eine mutationsbedingte Glykosylierung des M2-Proteins führte jedoch unerwartet zu einer verstärkten Immunantwort in vivo, die trotz verbesserter AFC zu einem schwereren Krankheitsverlauf führte. Grund dafür könnte eine Aktivierung der Unfolded Protein Response aufgrund der Glykosylierung sein. Die Erkenntnis, dass M2 ein wichtiger Modulator in der Regulation der alveolären Flüssigkeitshomöostase ist, könnte dennoch helfen, neue therapeutische Ansätze für IV-induzierte Pneumonien zu definieren. Darüber hinaus unterstreicht es die Relevanz einer in der vorliegenden Arbeit durchgeführten Surfactome-Analyse zur Identifizierung neuer potentieller Angriffspunkte an der Zelloberfläche IV-infizierter Zellen, die in der antiviralen Therapie von Bedeutung sein könnten. / Influenza Virus (IV) infections of the lower respiratory tract can induce viral pneumonia resulting in acute lung injury (ALI/ARDS) with fatal outcome. Characteristics of an IV-induced pneumonia are alveolar epithelial cell (AEC) damage and accumulation of protein-rich edema fluid in the alveolar compartment impairing gas exchange. Depending on a sodium gradient established by the basolateral Na,K-ATPase (NKA) and the apical epithelial sodium channel (ENaC) edema fluid is removed from the alveolar space under normal conditions. However, after IV-infection various ion channels are dysregulated and reduced alveolar fluid clearance (AFC) is observed. An IV-infection leads to a reduced NKA expression in the non-infected neighbouring cells and to a mistargeting of the NKA to the apical cell membrane in IV-infected cells. Co immunoprecipitation (co-IP) studies identified the viral M2 protein as NKA binding partner and mutational analysis presented three amino acids in the cytoplasmic tail of M2 directly abutting the transmembrane domain as critical for NKA binding. A recombinant IV mutant with disrupted NKA binding showed in comparison to IV WT an increased fluid transport in polarized Calu 3 cells in vitro as well as in mice in vivo. However, mutation-induced glycosylation of the M2 protein unexpectedly led to an enhanced immune response in vivo, resulting in a more severe disease course despite improved AFC. The reason for this could be an activation of the unfolded protein response by the glycosylation of M2. Nevertheless, the finding that M2 appears to be an important modulator in the regulation of alveolar fluid homeostasis might provide new potential approaches for therapeutics of an IV induced pneumonia. Moreover, it highlights the relevance of a surfactome analysis performed in the present work to identify novel potential targets on the cell surface of IV-infected cells which could play an important role in antiviral therapy.

Die Familie der ErbB-Rezeptor-Tyrosinkinasen besteht aus vier Mitgliedern, dem EGF-Rezeptor (ErbB-1), ErbB-2, ErbB-3 und ErbB-4. ErbB-Rezeptoren spielen eine wichtige Rolle bei der Entwicklung des Nervensystems, des Herzens und der Brustdrüsen. Ein Teil dieser Differenzierungsvorgänge läßt sich in vitro nachvollziehen: so ist zum Beispiel die Aktivierung des ErbB-2 Rezeptors ausreichend für alveoläre Morphogenese der Brustdrüsenepithelzellinie EpH4. Intrazelluläre Moleküle, die dieses ErbB2-Signal übertragen, sind allerdings noch unbekannt. Mit Hilfe eines neuen, modifizierten Hefe-2-Hybrid-Systems wurde in der vorliegenden Arbeit Vav2 als neuer Interaktionspartner von ErbB-2 identifiziert. Vav2 assoziiert mit aktiviertem ErbB-2 über eine SH2-Domäne. Die Interaktion ist direkt und ist von zwei Phosphotyrosinen in ErbB-2 abhängig. Vav2 kann den GDP/GTP-Austausch bei GTPasen der Rho-Familie vermitteln. Dadurch kann der Umbau des Zytoskeletts und Veränderungen der Transkription sowie Zelltransformation induziert werden. In einem dreidimensionalen Zellkultursystem kann aktiviertes Vav2 in EpH4 Zellen die Bildung von alveolären Zellaggregaten induzieren. In diesen Alveolen umgibt eine Schicht polarisierter milchproduzierender Zellen ein zentrales Lumen. Diese Vav2-vermittelte Morphogenese ist abhängig von der katalytischen GDP/GTP-Austausch Aktivität von Vav2. Katalytisch-inaktives Vav2 kann die morphogenetische Aktivität von ErbB-2 in EpH4-Zellen verhindern, ohne die mitogene Aktivität von ErbB-2 zu beeinflussen. Vav2 ist mit ErbB-2 coexprimiert und interagiert mit dem Rezeptor in Brustdrüsenzellen schwangerer Mäuse. Diese Untersuchungen deuten darauf hin, dass Vav2 eine wichtige Funktion bei der durch ErbB-2 induzierten alveolären Morphogenese der Brustdrüse spielt. / The ErbB receptor tyrosine kinases constitute a subfamily of four structurally related members, the EGF receptor (ErbB-1), ErbB-2, ErbB-3 and ErbB-4. ErbB receptor tyrosine kinases are critical for embryonic development of central and peripheral neural structures and heart. In addition, ErbB receptors play an important role in the postnatal development of the mammary gland. Previous studies showed that activated ErbB-2 receptor induces alveolar morphogenesis of EpH4 mammary epithelial cells that are cultured on a three-dimensional matrix (termed Matrigel). However, the downstream signaling proteins that mediate this biological activity of ErbB-2 were unknown. In this work, Vav2 was identified as a direct interaction partner of tyrosine-phosphorylated ErbB receptors using the yeast two-hybrid system. Vav2 is a member of a family of guanine nucleotide exchange factors that induce cytoskeletal rearrangements, transcriptional alterations, and have oncogenic potential when activated. To test the ability of Vav2 to mediate morphogenic signals of ErbB-2, EpH4 cells overexpressing Vav2 protein were cultured on Matrigel. Indeed, Vav2 induces alveolar morphogenesis of EpH4 cells when activated either by oncogenic mutation or tyrosine phosphorylation by ErbB-2. The morphogenic activity of Vav2 requires the Dbl homology domain, which mediates GDP/GTP exchange. Dominant-negative Vav2 specifically blocks the morphogenic signals of ErbB-2 in EpH4 cells without interfering with ErbB2-induced mitogenesis. Importantly, Vav2 is co-expressed and interacts with ErbB-2 in the mammary glands of pregnant mice. Taken together, these results point to Vav2 as a candidate to mediate ErbB-2 signals for alveolar morphogenesis in vivo, which is a relevant step in the development of the mammary gland during pregnancy.

Die Ergebnisse der Arbeit weisen mehrfach auf eine defizitäre IL-10 Produktion in Alveolarmakrophagen von Asthmatikern hin. Die reduzierte IL-10 Expression auf Protein- und Genebene korrelierte mit einer erhöhten Produktion proinflammatorischer Zytokine (TNF-?, MIP1-?, GM-CSF). Diese Beobachtung impliziert einen Defekt in der IL-10 Synthese, der in einer verstärkten und prolongierten pulmonalen Entzündungsantwort resultiert. Daraus läßt sich schlußfolgern, dass beim Asthma bronchiale eine Dysbalance zwischen pro- und antiinflammatorischen Zytokinen pathogenetisch von Bedeutung ist. Die verringerte Sensitivität von Alveolarmakrophagen auf die inhibitorischen Effekte von exogenem IL-10 im Vergleich zu Blutmonozyten ist durch Unterschiede in den Mechanismen der Signaltransduktion bedingt (37, 54). Der Nachweis der Expression von proinflammatorischen Zytokinen in Bronchialmyozyten (RANTES, IL-8) führte zu einer Neubewertung dieser Zellen als Immuneffektorzellen in der Pathogenese des Asthma bronchiale. Neben der Kontraktilität sind Myozyten auch aktiv an der Aufrechterhaltung der Atemwegsentzündung beteiligt. Die inhibitorischen Effekte von IL-10 und IL-13 auf die Synthese proinflammatorischer Chemokine (RANTES, IL-8, MIP-1() in migrierten Entzündungszellen und residenten Bronchialmyozyten konnten in verschiedenen Arbeiten gut dokumentiert werden. Die Vielzahl antiinflammatorischer Effekte von IL-10, die sich auf unterschiedliche Zellsysteme wie Monozyten, Makrophagen und Bronchialmyozyten erstrecken, unterstreicht die pathogenetische Bedeutung dieses Zytokins. Der molekulare Mechanismus, welcher die IL-10 Wirkung vermittelt, ist derzeit noch nicht vollständig aufgeklärt. Angenommen wird eine rezeptorvermittelte Inhibition von Transkriptionsfaktoren des Stat Systems und NF-(B (76). Zukünftige molekularbiologische und klinische Studien sind jedoch notwendig, um den Kenntnisstand der Effekte antiinflammatorischer Zytokine zu vertiefen, und die Gabe von rekombinantem IL-10 als möglichen Ansatz zur Therapie chronisch entzündlicher Lungenerkrankungen zu evaluieren (81). / The results of this present thesis show a deficiency of IL-10 production in alveolar macrophages in asthma. The reduced IL-10 expression on protein and m-RNA level correlated with an increased production of pro-inflammatory cytokines such as TNF-(, MIP1- ( and GM-CSF. These observations implicate an impaired IL-10 synthesis in asthma with a subsequent prolongation of the inflammatory response. This leads to the conclusion that a dysbalance between pro- and anti-inflammatory cytokines is present in asthma and may be therefore of pathogenetic importance. The reduced sensitivity of alveolar macrophages to the inhibitory effects of exogenous IL-10 compared to peripheral blood monocytes may be caused by different signal transduction mechanisms. The expression of the proinflammatory cytokines RANTES and IL-8 in cultured human airway smooth muscle cells led to the conclusion that airway smooth muscle cells may act beside their contractile function as immunomodulatory cells in the pathogenesis of asthma. The inhibitory effects of IL-10 and IL-13 on the synthesis of proinflammatory cytokines (RANTES, IL-8, MIP1-() in immigrated inflammatory cells and resident cells such as airway smooth muscle cells have been shown in several publications that are part of the present thesis. The numerous antiinflammatory effects of IL-10 on different inflammatory cell systems such as monocytes/macrophages and smooth muscle cells underline the pathogenetic importance of this cytokine. The molecular mechanisms that mediate the IL-10 effects involve the transcription factors NF-(B and the Stat-System. Future studies are needed to determine the molecular mechanisms of the anti-inflammatory effects of IL-10 and IL-13 more deeply and to evaluate their application for the therapy of chronic inflammatory pulmonary diseases.

INTRODUÇÃO: O uso de níveis elevados da pressão expiratória final positiva (PEEP) na Síndrome do desconforto respiratório agudo (SDRA), visando reduzir a quantidade de pulmão colapsado, tornando a ventilação mais homogênea, tem sido apontado por estudos clínicos randomizados e metaanálises como uma estratégia eficaz na melhora de alguns desfechos clínicos. Atualmente, não existe um método ideal para ajuste da PEEP na SDRA. Dois métodos distinguem-se pela racionalidade fisiológica e possibilidade de serem usados na prática clínica usual: ajuste da PEEP guiado por Pressão Esofágica (Pes) e ajuste da PEEP guiado por Tomografia de Impedância Elétrica (TIE). Os objetivos do estudo foram: (1) Avaliar, através de tomografia computadorizada de tórax (raios X), qual estratégia induz uma melhor aeração pulmonar: maior recrutamento pulmonar e menor hiperdistensão; (2) Avaliar as alterações da distribuição regional da ventilação, do volume pulmonar e da complacência regional medidos pela tomografia de impedância elétrica; (3) Avaliar as alterações na mecânica pulmonar e nas trocas gasosas produzidas por ambas as estratégias de titulação da PEEP. MÉTODOS: Dez porcos foram submetidos a um modelo de SDRA grave: depleção de surfactante mais lesão pulmonar induzida pelo ventilador. Após uma manobra de recrutamento (MR), duas estratégias de titulação da PEEP foram testadas em uma sequência aleatória: 1) Utilizando a tomografia por impedância elétrica para calcular a menor PEEP que mantem um colapso pulmonar menor de 1%; 2) Utilizando a pressão esofágica para calcular a PEEP necessária para atingir uma pressão transpulmonar final expiratória (PLexp) entre 5-6 cmH2O. Em seguida, os animais foram ventilados durante 1 hora com a PEEP ótima estimada por cada método. Foram registrados parâmetros fisiológicos e de tomografia computadorizada (TC) antes da MR (tempo basal) e após ventilação com a PEEP ótima (15 min e 60 min). RESULTADOS: Aos 60 min, ambas as estratégias reduziram o colapso pulmonar, mas com efeitos significativamente maiores (P < 0,05) no grupo TIE: tecido não-aerado (20,3 ± 11,8% vs. 38,6 ± 13,1%, TIE vs. Pes respectivamente), recrutamento cíclico (4,8 ± 3,7% vs. 8,7 ± 2,7%), PaO2/FIO2 (289 ± 78 vs. 209 ± 92 mmHg), pressão de distensão (14,5 ± 2,3 vs. 16,1 ± 2,3 cmH2O), e pressão de distensão transpulmonar (11,9 ± 1,7 vs. 13,6 ± 1,8 cmH2O). Apesar da escolha de uma maior PEEP ótima no grupo TIE, a pressão platô (33,2 ± 3,7 vs. 31,5 ± 3,1 cmH2O), a pressão transpulmonar inspiratória final (20,0 ± 2,8 vs. 19,2 ± 1,7 cm H2O) e a complacência das áreas não dependentes do pulmão medidas pela TIE (0,07 ± 0,04 vs 0,06 ± 0,05 unidades arbitrárias/cmH2O) ou TC (1,52 ± 0,90 vs. 1,41 ± 0,98 mL/cmH2O) variaram de forma semelhante nos dois grupos (P > 0,05). O tecido hiperaerado e a hipedistensão cíclica foram baixos em ambos os grupos. CONCLUSÕES: Neste modelo animal de SDRA grave o ajuste da PEEP guiado por TIE produz um maior recrutamento pulmonar e sinais fisiológicas de melhor proteção pulmonar quando comparado com o ajuste da PEEP guiado por Pes / INTRODUCTION: The use of higher levels of positive end-expiratory pressure (PEEP) in the acute respiratory distress syndrome (ARDS), aimed at reducing the amount of lung collapse, making the ventilation more homogeneous, has been pointed out by randomized clinical trials and meta-analysis as an effective strategy to improve some clinical outcomes. Currently, there is no ideal method for adjustment PEEP in ARDS. Two methods are distinguished by their physiological rationality and the possibility of being used in the clinical practice: PEEP titration guided by Esophageal Pressure (Pes) and PEEP titration guided by Electrical Impedance Tomography (EIT). The objectives of the study were: 1) To evaluate through computed tomography of thorax (X-ray), which strategy induces better pulmonary aeration: greater lung recruitment and less hyperdistension; (2) To evaluate changes in the regional distribution of ventilation, pulmonary volume and regional compliance, measured by electrical impedance tomography; (3) To assess changes in lung mechanics and gas exchange produced by both PEEP titration strategies. METHODS: Ten pigs were submitted to a two-hit model of severe ARDS: Surfactant depletion plus ventilator-induced lung injury. After a recruitment maneuver (RM), two strategies of PEEP titration were tested in a randomized sequence: 1) Using electric impedance tomography to calculate the lowest PEEP keeping recruitable-lungcollapse < 1%; 2) Using esophageal pressure to calculate the PEEP needed to achieve an end-expiratory transpulmonary pressure between 5-6 cmH2O. Then, animals were ventilated for 1 hour with the optimum-PEEP estimated by each method. Physiological and computed tomography (CT) parameters were recorded before RM (baseline) and after ventilation at optimum-PEEP (15 min and 60 min). RESULTS: At 60 min, both strategies reduced lung collapse but with significantly (P < 0.05) greater effects in EIT-group: nonaerated tissue (20.3 ± 11.8% vs 38.6 ± 13.1%, EIT vs. Pes, respectively), tidal recruitment (4.8 ± 3.7% vs 8.7 ± 2.7%), PaO2/FIO2 (289 ± 78 vs 209 ± 92 mmHg), driving-pressure (14.5 ± 2.3 vs 16.1 ± 2.3 cmH2O) and transpulmonary driving-pressure (11.9 ± 1.7 vs 13.6 ± 1.8 cmH2O). Despite the choice for a higher optimum-PEEP in the EIT-group; plateau pressure (33.2 ± 3.7 vs 31.5 ± 3.1 cmH2O), end-inspiratory transpulmonary pressure (20.0 ± 2.8 vs 19.2 ± 1.7 cmH2O) and compliance of non-dependent areas measured by EIT (0.07 ± 0.04 vs 0.06 ± 0.05 arbitrary units/cmH2O) or CT (1.52 ± 0.90 vs 1.41 ± 0.98 mL/cmH2O) varied similarly in both groups (P > 0.05). Hyperaerated tissue and tidal hyperinflation were very low in both groups. CONCLUSION: In this model, the choice of PEEP guided by EIT leads to higher lung recruitment and physiological signals of a better lung protection, when compared to the strategy guided by Pes

INTRODUÇÃO: O uso de níveis elevados da pressão expiratória final positiva (PEEP) na Síndrome do desconforto respiratório agudo (SDRA), visando reduzir a quantidade de pulmão colapsado, tornando a ventilação mais homogênea, tem sido apontado por estudos clínicos randomizados e metaanálises como uma estratégia eficaz na melhora de alguns desfechos clínicos. Atualmente, não existe um método ideal para ajuste da PEEP na SDRA. Dois métodos distinguem-se pela racionalidade fisiológica e possibilidade de serem usados na prática clínica usual: ajuste da PEEP guiado por Pressão Esofágica (Pes) e ajuste da PEEP guiado por Tomografia de Impedância Elétrica (TIE). Os objetivos do estudo foram: (1) Avaliar, através de tomografia computadorizada de tórax (raios X), qual estratégia induz uma melhor aeração pulmonar: maior recrutamento pulmonar e menor hiperdistensão; (2) Avaliar as alterações da distribuição regional da ventilação, do volume pulmonar e da complacência regional medidos pela tomografia de impedância elétrica; (3) Avaliar as alterações na mecânica pulmonar e nas trocas gasosas produzidas por ambas as estratégias de titulação da PEEP. MÉTODOS: Dez porcos foram submetidos a um modelo de SDRA grave: depleção de surfactante mais lesão pulmonar induzida pelo ventilador. Após uma manobra de recrutamento (MR), duas estratégias de titulação da PEEP foram testadas em uma sequência aleatória: 1) Utilizando a tomografia por impedância elétrica para calcular a menor PEEP que mantem um colapso pulmonar menor de 1%; 2) Utilizando a pressão esofágica para calcular a PEEP necessária para atingir uma pressão transpulmonar final expiratória (PLexp) entre 5-6 cmH2O. Em seguida, os animais foram ventilados durante 1 hora com a PEEP ótima estimada por cada método. Foram registrados parâmetros fisiológicos e de tomografia computadorizada (TC) antes da MR (tempo basal) e após ventilação com a PEEP ótima (15 min e 60 min). RESULTADOS: Aos 60 min, ambas as estratégias reduziram o colapso pulmonar, mas com efeitos significativamente maiores (P < 0,05) no grupo TIE: tecido não-aerado (20,3 ± 11,8% vs. 38,6 ± 13,1%, TIE vs. Pes respectivamente), recrutamento cíclico (4,8 ± 3,7% vs. 8,7 ± 2,7%), PaO2/FIO2 (289 ± 78 vs. 209 ± 92 mmHg), pressão de distensão (14,5 ± 2,3 vs. 16,1 ± 2,3 cmH2O), e pressão de distensão transpulmonar (11,9 ± 1,7 vs. 13,6 ± 1,8 cmH2O). Apesar da escolha de uma maior PEEP ótima no grupo TIE, a pressão platô (33,2 ± 3,7 vs. 31,5 ± 3,1 cmH2O), a pressão transpulmonar inspiratória final (20,0 ± 2,8 vs. 19,2 ± 1,7 cm H2O) e a complacência das áreas não dependentes do pulmão medidas pela TIE (0,07 ± 0,04 vs 0,06 ± 0,05 unidades arbitrárias/cmH2O) ou TC (1,52 ± 0,90 vs. 1,41 ± 0,98 mL/cmH2O) variaram de forma semelhante nos dois grupos (P > 0,05). O tecido hiperaerado e a hipedistensão cíclica foram baixos em ambos os grupos. CONCLUSÕES: Neste modelo animal de SDRA grave o ajuste da PEEP guiado por TIE produz um maior recrutamento pulmonar e sinais fisiológicas de melhor proteção pulmonar quando comparado com o ajuste da PEEP guiado por Pes / INTRODUCTION: The use of higher levels of positive end-expiratory pressure (PEEP) in the acute respiratory distress syndrome (ARDS), aimed at reducing the amount of lung collapse, making the ventilation more homogeneous, has been pointed out by randomized clinical trials and meta-analysis as an effective strategy to improve some clinical outcomes. Currently, there is no ideal method for adjustment PEEP in ARDS. Two methods are distinguished by their physiological rationality and the possibility of being used in the clinical practice: PEEP titration guided by Esophageal Pressure (Pes) and PEEP titration guided by Electrical Impedance Tomography (EIT). The objectives of the study were: 1) To evaluate through computed tomography of thorax (X-ray), which strategy induces better pulmonary aeration: greater lung recruitment and less hyperdistension; (2) To evaluate changes in the regional distribution of ventilation, pulmonary volume and regional compliance, measured by electrical impedance tomography; (3) To assess changes in lung mechanics and gas exchange produced by both PEEP titration strategies. METHODS: Ten pigs were submitted to a two-hit model of severe ARDS: Surfactant depletion plus ventilator-induced lung injury. After a recruitment maneuver (RM), two strategies of PEEP titration were tested in a randomized sequence: 1) Using electric impedance tomography to calculate the lowest PEEP keeping recruitable-lungcollapse < 1%; 2) Using esophageal pressure to calculate the PEEP needed to achieve an end-expiratory transpulmonary pressure between 5-6 cmH2O. Then, animals were ventilated for 1 hour with the optimum-PEEP estimated by each method. Physiological and computed tomography (CT) parameters were recorded before RM (baseline) and after ventilation at optimum-PEEP (15 min and 60 min). RESULTS: At 60 min, both strategies reduced lung collapse but with significantly (P < 0.05) greater effects in EIT-group: nonaerated tissue (20.3 ± 11.8% vs 38.6 ± 13.1%, EIT vs. Pes, respectively), tidal recruitment (4.8 ± 3.7% vs 8.7 ± 2.7%), PaO2/FIO2 (289 ± 78 vs 209 ± 92 mmHg), driving-pressure (14.5 ± 2.3 vs 16.1 ± 2.3 cmH2O) and transpulmonary driving-pressure (11.9 ± 1.7 vs 13.6 ± 1.8 cmH2O). Despite the choice for a higher optimum-PEEP in the EIT-group; plateau pressure (33.2 ± 3.7 vs 31.5 ± 3.1 cmH2O), end-inspiratory transpulmonary pressure (20.0 ± 2.8 vs 19.2 ± 1.7 cmH2O) and compliance of non-dependent areas measured by EIT (0.07 ± 0.04 vs 0.06 ± 0.05 arbitrary units/cmH2O) or CT (1.52 ± 0.90 vs 1.41 ± 0.98 mL/cmH2O) varied similarly in both groups (P > 0.05). Hyperaerated tissue and tidal hyperinflation were very low in both groups. CONCLUSION: In this model, the choice of PEEP guided by EIT leads to higher lung recruitment and physiological signals of a better lung protection, when compared to the strategy guided by Pes

This thesis has, commissioned by Dräger, an international company at the forefront of medical and safety technology, examined how the use of inhalational anesthetics affects the climate and environment. The purpose of this work is to examine how the Swedish healthcare sector currently works with inhalational anesthetics, how different anesthetic machines affect the emissions, as well as alternatives available to reduce anesthetic gases emissions. Climate change is a current issue in today’s society, but the impact of anesthetic gases on the climate is not widely known, despite their everyday use in the healthcare sector. Through data collection from two Swedish hospitals; Linköping University Hospital and Örebro University Hospital, an interview with medical and medical engineering staff, as well as a literature study the main question of the thesis could be answered; How do the most common anesthetic gases affect the environment? The results are presented in the form of diagrams showing the amount of anesthetic gas used in the aforementioned hospitals during surgeries. The results have been analyzed and discussed based on the research questions, and the different results from each hospital have been compared to each other. It can be seen that Dräger’s anesthesia machines have a relatively low consumption of sevoflurane, but it is impossible to draw any definitive conclusions due to lack of data, and lack of access to machines from other manufacturers. / Detta examensarbete har, på uppdrag av Dräger, ett internationellt företag i framkant inom medicin- och säkerhetsteknik, undersökt hur användning av inhalationsanestetika påverkar miljön. Målet med arbetet är att undersöka hur den svenska sjukvården för närvarande arbetar med inhalationsanestetika, hur olika anestesimaskiner påverkar utsläppen, samt alternativ som finns tillgängliga för att minska dessa utsläpp. Klimatförändringar är en aktuell fråga i dagens samhälle men påverkan av anestesigaser på klimatet är inte allmänt känt, trots att dessa används dagligen i hälsovården. Genom datainsamling från två svenska sjukhus; Linköpings Universitetssjukhus och Örebro Universitetssjukhus, intervjuer med medicinsk- och medicinteknisk personal, samt en litteraturstudie har arbetets problemställning besvarats; Hur påverkar de mest frekvent använda anestesigaserna miljön? Resultaten visar i diagramform hur mycket anestesi gas som använts i tidigare nämnda sjukhus under operationer. Resultaten har analyserats och diskuterats utifrån forskningsfrågorna, dessutom har de olika resultaten från respektive sjukhus jämförts med varandra. Det kan ses att Drägers anestesimaskiner har en relativt låg konsumtion av sevofluran, men brist på data samt brist på tillgång till maskiner från andra producenter gör det omöjligt att dra en konkret slutsats.

Describe la frecuencia de tipo de reborde residual alveolar según la clasificación de Seibert asociado a edad e historia de uso previo o no de prótesis completa. Estudio descriptivo, observacional y transversal, la muestra está conformada por 30 pacientes. Mediante examen clínico intraoral se registra la información obtenida en una ficha de recolección de datos. Es analizado mediante estadística descriptiva, aplicando el paquete estadístico SPSS 21.0. De los resultados se concluye que el reborde alveolar residual tipo 2 de Seibert es el que más se presenta en la muestra. La reabsorción del reborde alveolar residual aumenta en pacientes de edad avanzada y un factor que influye es la prótesis dental. / Tesis