A antibioticoterapia em cirurgias de terceiros molares inferiores inclusos e/ou impactados é um assunto controverso no meio odontológico. O objetivo do presente estudo foi elucidar a real necessidade de prescrição de antibióticos nestes tipos de cirurgias realizadas por três operadores com experiências clínicas distintas. Um especialista, uma doutoranda e um aluno do último ano da graduação realizaram 50 cirurgias cada um, todas com remoção de osso e alto grau de dificuldade. Antibióticos não foram prescritos nos períodos pré e pós-operatório. No período préoperatório, 2o e 7o dias pós-operatórios foram analisados os seguintes parâmetros: dor, edema, trismo, temperatura corpórea, níveis de proteína C-reativa e contagem de neutrófilos salivares. Durante a cirurgia foram analisados: pressão arterial sistólica, diastólica e média, oximetria, freqüência cardíaca, qualidade da anestesia, quantidade de anestésico local, sangramento, dificuldade e tempo de duração da cirurgia. No dia da retirada de pontos, 7o dia pós-cirúrgico, foi avaliada a qualidade de cicatrização e os voluntários relataram a avaliação global do período póscirúrgico. Não houve nenhum caso comprovado de alveolite ou outro tipo de infecção no local operado. O tempo de cirurgia do graduando e da doutoranda mostraram valores médios maiores que os do especialista (p<0,05). Houve diferença estatisticamente significativa entre o graduando e os outros dois operadores nos seguintes parâmetros: qualidade da anestesia, quantidade de tubetes utilizados, sangramento no momento da incisão, trismo e dor em vários momentos pósoperatórios (p<0,05). Não houve mudanças significativas nos parâmetros hemodinâmicos durante as cirurgias. Os voluntários operados pela doutoranda tiveram uma recuperação da abertura de boca melhor que os operados pelos outros dois operadores (95,88±1,67% para a doutoranda, 86,87±2,05% para o especialista e 79,51±3,05% para o graduando, p<0,05). Houve diferença estatisticamente significativa nos níveis de proteína C-reativa no 2o dia de pós-operatório entre o graduando e o especialista e entre o graduando e a doutoranda (20,39±2,77 mg/L, 18,83±3,94 mg/L e 9,31±0,68 mg/L, respectivamente, p<0,05) e na contagem de neutrófilos salivares no 2o dia de pós-operatório entre os voluntários operados pelo graduando e os operados pela doutoranda (248±41,01 e 78,40±14,51 respectivamente, p<0,05). Os voluntários operados pela doutoranda avaliaram mais positivamente o período pós-cirúrgico em relação àqueles operados pelos outros dois operadores, possivelmente pela menor força e maior delicadeza exercida no momento da cirurgia. A análise conjunta dos resultados obtidos nesta pesquisa permite concluir que a antibioticoterapia mostra-se desnecessária em cirurgias de terceiros molares com necessidade de osteotomia independentemente da experiência do operador. / The use of antibiotics in lower third molar surgeries with necessity of boné removal is controversial. The aim of this study was to elucidate the real necessity of antibiotics prescription in such types of surgeries performed by three different surgeons with distinct clinical experiences. A specialist, a PhD student and a senior dental student performed 50 surgeries each, all with osteotomy and high degree of difficulty. Antibiotics were not prescribed either before or after surgeries. In the preoperatory period and on the second and seventh postoperative days, the following parameters were analyzed: pain, swelling, trismus, body temperature, C-reactive protein levels and salivary neutrophil count. During the surgeries the following parameters were analyzed: systolic, diastolic and mean arterial pressure, oxymetry, heart rate, quality of anesthesia, amount of local anesthetic, bleeding, surgery difficulty and duration of surgery. At the suture removal, seventh postoperative day, quality of wound healing and global evaluation performed by the patient were recorded. There was no confirmed case of dry socket or another type of local infection in the study. The duration of surgeries performed by the senior student and the PhD student showed higher values as compared to the specialist (p<.05). There was statistically significant difference between the senior student compared to both surgeons in the following parameters: quality of anesthesia, amount of local anesthetic, bleeding at incision time, trismus and pain at several postoperative times (p<.05). There were no significant changes in hemodynamic parameters during the surgeries. The PhD students volunteers had better recovery of mouth opening in comparison with the volunteers of the other surgeons (95.88±1.67% for the PhD student, 86.87±2.05% for the specialist, and 79.51±3.05% for the senior student, p<.05). There was significant statistically difference in C-reactive protein levels between the senior student and the specialist, and between the senior student and the PhD student (20.39±2.77 mg/L, 18.83±3.94 mg/L and 9.31±0.68 mg/L, respectively, p<.05), and in salivary neutrophil counts on the second postoperative day between the senior students patients and the PhD students patients (248±41.01 and 78.40±14.51 respectively, p<.05). The PhD students volunteers evaluated the postoperative period more positively in comparison to the volunteers of the other surgeons. Taken together, the results of the present work allow to conclude that antibiotics prescription is not necessary in lower third molar removal with osteotomy regardless of the surgeons experience.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A ExtraÃÃo do terceiro molar à um procedimento comum, freqÃentemente associado com dor de intensidade de moderada ou grave, e que afeta um nÃmero significante de pacientes, o que torna os estudos clÃnicos que avaliam a dor associada com a exodontia dos terceiros molares relativamente fÃceis de se executar. O objetivo deste estudo foi determinar a eficÃcia e a seguranÃa da combinaÃÃo terapÃutica de piroxicam, dexametasona, citrato de orfenadrina e cianocobalamina (RheumazinÂ) em comparaÃÃo ao piroxicam isoladamente (FeldeneÂ) em um modelo de cirurgia do terceiro molar inferior. Neste estudo, que foi do tipo randomizado e duplo cego, foram incluÃdos oitenta pacientes selecionados para a exodontia do terceiro molar inferior. Os pacientes receberam Rheumazin ou Feldene 30 min depois da extraÃÃo do terceiro molar inferior e, a partir daÃ, uma vez ao dia durante 4 dias sucessivos. A intensidade da dor foi determinada por meio de uma escala visual analÃgica e pela quantidade de medicaÃÃo de escape utilizada pelos pacientes (paracetamol). O edema facial foi avaliado atravÃs de medidas da face usando uma escala mÃtrica calibrada (mm). Ainda, foram tambÃm avaliados os efeitos adversos e o grau de satisfaÃÃo em relaÃÃo aos tratamentos, ambos relatados pelos pacientes. Embora os resultados tenham mostrado que nÃo houve diferenÃa estatÃstica no edema facial entre os dois grupos, Rheumazin reduziu a dor na 6a e 120a h de tratamento. Rheumazin tambÃm demonstrou um melhor perfil de seguranÃa, prevenindo efeitos adversos tais como nÃusea, indisposiÃÃo e dor epigÃstrica, dentre outros, quando comparado ao FeldeneÂ. Este achado torna o Rheumazin uma boa opÃÃo para o tratamento no pÃs-operatÃrio da remoÃÃo do terceiro molar inferior. / Third molar extraction is a common procedure with pain frequently moderate or severe in intensity, and with sufficient numbers of patients to make studies relatively easy to perform. The aim of this study was to determine the efficacy and the safety of the therapeutic combination of piroxicam, dexamethasone, orphenadrine citrate and cyanocobalamin (RheumazinÂ) in comparison to piroxicam alone (FeldeneÂ) in a mandibular third molar surgery model. Eighty patients selected for removal of the third molar were included in this study which was randomized and double blind. They received Rheumazin or Feldene po 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated using a tape measuring method. Record of adverse effects and patientâs satisfaction was also considered. Although the results showed that there was no statistically significant difference in facial swelling between the two groups, Rheumazin reduced pain at 6th and 120th h of treatment. Rheumazin also demonstrated a better safety profile preventing adverse effects including nausea, indisposition and epigastric pain, among others, when compared to FeldeneÂ. This fact makes Rheumazin a good choice for post-surgery treatment in third molar removal

L'objectif général de notre travail de thèse a été d'évaluer le rapport bénéfice/risque cardiovasculaire de l'exercice immergé. L'exercice immergé est contraignant pour le système cardiovasculaire. Il est potentiellement responsable d'une majoration de la perméabilité et/ou du gradient de pression de la barrière alvéolo-capillaire. Cet effet passe par le biais d'un accroissement des charges cardiaque et respiratoire, une sécrétion de peptides natriurétiques et une hémodilution. L'exposition au froid, la consommation d'anti-inflammatoires non stéroïdiens et la réalisation d'un exercice de forte intensité majorent le risque de survenue d'un oedème pulmonaire d'immersion. L'exercice immergé a également des effets bénéfiques. La pratique d'un sport aquatique aurait le même effet anti-hypertenseur que les activités réalisées en ambiance sèche. Par ailleurs, des différences de sollicitation endothéliale pourraient exister, en fonction des modalités d'exercice ou de la position du sujet. L'exercice immergé pourrait être plus efficace sur la perte de poids et le contrôle des facteurs de risque cardiovasculaires métaboliques, par le biais des sécrétions endocrines qu'il induit. Enfin, le réchauffement cutané associé à l'immersion dans une eau thermiquement neutre semble cardio-protecteur. / The aim of our PhD was to hold up the knowledge about risks and benefits of immersed exercise.Immersed exercise is a stress for cardiovascular system. It may result in an increase in permeability and/or pressure gradient, at the level of alveolar-capillary membrane. These effects result from an increase in cardiac and respiratory load, a natriuretic peptide secretion, and hemodilution. Exposure to cold, non-steroïdal anti-inflammatory drugs, and high intensity exercise increase the risk of a pulmonary oedema of immersion occurrence. Immersed exercise also have beneficial effects. Our observatsion suggest that immersed exercise have the hypotensive effects as ambient air exercise. Differences in endothelial stimulation may exist, depending on exercise modalities. Immersed exercise may even be more efficient on weight loss and cardiovascular risk factors control than ambient air exercise, through alterations in endocrine secretions. At the end, the global warming of the skin related to immersion in thermoneutral water appears to be cardio-protective.

De très nombreuses pathologies cérébrales s’accompagnent de phénomènes inflammatoires soit primitifs comme dans la sclérose en plaques (SEP), soit secondaires comme après un infarctus cérébral ou un traumatisme crânien. Dans tous les cas on observe la présence d’œdème vasogénique et de cellules inflammatoires.Dans une première approche chez l’animal, nous avons étudié la régulation et le rôle de la protéine canal aquaporine 4 (AQP4) dans l’œdème associé à l’inflammation et dans la sévérité de l’inflammation elle-même. Nous avons, de plus, validé un modèle de lésion inflammatoire focale type SEP pour étudier l’œdème et l’inflammation en fonction du microenvironnement, soit dans la substance blanche (SB), soit dans la substance grise (SG). Dans une seconde approche translationnelle chez les patients SEP, nous avons combiné un marqueur IRM d’altération de la barrière hémato-encéphalique (gadolinium) avec un marqueur plus spécifique de la composante cellulaire (USPIO) pour détecter les lésions « actives » et déterminer leur pronostic.Nous avons d’abord montré qu’AQP4 était surexprimée en situation d’œdème vasogénique associé à l’inflammation. Plus précisément, la surexpression d’AQP4 était plus marquée lors de la phase de résorption que lors de la phase de formation de l‘œdème. De plus, le fait d’inhiber AQP4 aggravait la sévérité de l’œdème et de l’inflammation dans la SB et dans la SG. Nous avons conclu au rôle protecteur d’AQP4 en situation d’inflammation en accord avec les données sur l’implication d’AQP4 dans la résorption de l’œdème et la mise en place de la cicatrice gliale. La surexpression d’AQP4, en tant que mécanisme protecteur, semblait insuffisante pour contrer la phase initiale de l’inflammation car elle ne devenait importante que secondairement. Deuxièmement, lorsque l’on induisait la même attaque inflammatoire dans la SB et dans la SG (modèle focal de SEP), les différences de microenvironnement ne permettaient pas d’induire de différence en termes de sévérité de l’œdème et de l’inflammation. Cette observation suggère de rechercher des différences de physiopathologie entre les lésions de la SB et celles de la SG pour expliquer le caractère faiblement inflammatoire et œdémateux des lésions de la SG chez les patients SEP. Pour finir, nous avons montré que l’observation de la composante cellulaire de l’inflammation in vivo grâce aux USPIO augmentait la sensibilité pour la détection des lésions actives de SEP. Les USPIO montraient également la faible inflammation résiduelle dans les formes chroniques de SEP. L’association des USPIO et du gadolinium augmentait également la spécificité en identifiant un sous-groupe de lésions se rehaussant avec les deux agents et apparaissant plus sévère.Nous avons apporté des connaissances nouvelles sur la physiopathologie de l’œdème et de la composante cellulaire de l’inflammation. Si nos résultats se confirment chez l’homme, l’AQP4 pourrait devenir une nouvelle cible thérapeutique. La meilleure compréhension des différences entre les lésions de la SB et de la SG dans la SEP est également une étape importante pour des thérapeutiques plus ciblées. Un bio-marqueur utilisable in vivo reflétant la composante cellulaire de l’inflammation (USPIO) améliore la sensibilité et la spécificité et pourrait aider à évaluer les nouvelles thérapeutiques. / Inflammation is a contributing factor in many diseases of the brain, including primary inflammatory disorders such as multiple sclerosis (MS) and secondary inflammation following stroke, brain trauma or even tumors. Vasogenic edema and white blood cell infiltration are common features of all inflammatory reaction subtypes. We first performed experimental studies in rodent animal models to better understand the regulation and role of the water channel protein aquaporin 4 (AQP4) in edema associated with inflammation and in the severity of the inflammation itself. We further validated a focal animal model of MS-like lesions to explore whether inflammation and edema differed according to the microenvironment either in gray matter (GM) or white matter (WM). In a second approach in MS patients, we combined a MR marker of blood brain barrier alteration (gadolinium) with a more specific marker of the cellular component of inflammation (USPIO) to detect active lesions and address their prognosis.First, we found that AQP4 was upregulated under conditions associated with vasogenic edema such as inflammation. Specifically, AQP4 upregulation was more important in the edema resolution phase than in the edema build-up phase. Furthermore, silencing AQP4 aggravated the severity of edema and inflammation in both WM and GM. We concluded that AQP4 has a protective role under inflammatory conditions, in agreement with the previously demonstrated role of AQP4 in edema resolution and glial scar formation. AQP4 upregulation, a potential protective mechanism, seems insufficient to counter the initial phase of inflammation because it reached a maximum only after a delay. Second, the severity of the edema and inflammation in WM and GM was not significantly different according to the microenvironment (either WM or GM) upon induction by the same inflammatory attack. This suggests that the pathogenesis in WM and GM is different and should be further explored to explain why little inflammation and edema is encountered in GM lesions of MS patients. Finally, we found that tracking the cellular macrophage component of inflammation with USPIO increased the sensitivity to active lesions in MS patients. It could even detect mild residual inflammation in patients with a progressive MS. Combining USPIO and gadolinium also increased the specificity; the subgroup of lesions that were enhanced with both contrast agents had more severe features. We have provided a better understanding of edema and the cellular component of inflammation. If confirmed in humans, AQP4 could be a new target for medication of edema. A better understanding of the WM/GM difference in MS is also a first step in developing more specific therapeutic strategies. Finally, the in vivo marker of the cellular component of inflammation (USPIO) provides more sensitive and specific information that could be useful in monitoring the efficacy of treatments.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2015-11-09T13:01:45Z No. of bitstreams: 1 texto completo.pdf: 1860106 bytes, checksum: 353b8088a255cf3282d4aa52ad5a282a (MD5) / Made available in DSpace on 2015-11-09T13:01:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1860106 bytes, checksum: 353b8088a255cf3282d4aa52ad5a282a (MD5) Previous issue date: 2207-07-31 / A utilização de plantas medicinais com fins terapêuticos, para tratamento, cura e prevenção de doenças, é uma das mais antigas formas de prática medicinal da humanidade. É cada vez mais freqüente o uso de plantas medicinais, mas muitas vezes as supostas propriedades farmacológicas anunciadas não possuem a validade científica, por não terem sido investigadas, ou por não tido suas ações farmacológicas comprovadas em testes científicos pré-clínicos e clínicos. O medicamento Kraftol é uma associação de extratos fluidos de Cinhona calisaya (Quina amarela), Cola acuminata (noz de cola), Paullinia cupana (guaraná), Iodo, Ácido tânico, Formato de sódio, Glicerofosfato de cálcio, Iodeto de potássio. É um medicamento indicado para o tratamento de convalescenças e nos estados de desnutrição, nas amgdalites, faringites e adenopatias. O objetivo do presente trabalho foi avaliar a ação antiedematogênica e antiulcerativa do medicamento Kraftol e do flavonóide Ipriflavona (7-isopropoxi-isoflavona), em processos inflamatórios como edema e ulcera gástrica em ratos machos da linhagem Wistar; e avaliar a atividade antiulcerativa dos extratos presentes no medicamento Kraftol de forma isoladamente e associados sem os sintéticos. Realizou-se também um estudo de toxicologia oral aguda e subcrônica (doses repetidas) do medicamento Kraftol, tendo como base a resolução No 90, de 16 de março de 2004 da ANVISA. Para o teste nos processos inflamatórios induziu-se edema na pata em ratos com a injeção de 0,02 ml da substância capsaicina (12,5 mg-1) e ácido araquidônico (2 mg/pata) e receberam o tratamento por via oral. As lesões gástricas foram induzidas com administração oral de ácido acetil salicílico (150mg/Kg em 1,5 ml de 0,2N HCl). Para avaliação da toxicidade pré-clínica os animais foram tratados por via oral com doses de acordo com Guia para realização de estudos de toxicidade pré-clínica de fitoterápicos, conforme a resolução vingente. Foram realizadas também análises bioquímicas complementares (leucograma, colesterol total, triglicerídeos, glicose , fosfatase alcalina, TGP, TGO, creatinina, uréia, potássio,ácido úrico, Gama GT) e análise macroscópica e microscópica dos órgãos quando necessário. / The use of medicinal plants with therapeutics purposes for treatment, cure and prevention of diseases is one of most ancient medical practices of humanity. The use of medicinal plants is increasingly spreading, but many times the allegedly pharmacological properties have no scientific validity either because they have not been investigated or because their pharmacological actions have not been proved in pre-clinical and clinical scientific tests. The medicine Kraftol is an association of fluid extracts of Cinhona calisaya (yellow kina), Cola acuminata (cola nut), Paullinia cupana (guaraná), Iodine, tannic acid, sodium phormate, calcium glycerophosphate, potassium iodate. It is a medicine indicated for the treatment of recovery and malnutrition, amygdalitis, pharingitis and adenophaties. The objective of the present work was to evaluate the antiedematogenic and antiulcer action of the medicine Kraftol and of the flavonoid Ipriflavone (7-isopropoxi-isoflavone), in inflammatory processes such as edema and gastric ulcer in Wistar breed male mice; and evaluate the antiulcer activity of the extracts present in the medicine Kraftol, isolatedly and associated without the synthetics. It was also carried out a study on oral sharp and subchronic toxology (repeated doses) of the medicine Kraftol, based on the ANVISA resolution 90, March 16, 2004. For the test in the inflammatory processes, an edema was induced in mice legs by injecting 0,02 ml of the capsaicin substance (12,5 mg -1) and arachdonic acid (2 mg/leg) as well as oral treatment. The gastric wounds were induced by oral administration of acetylsalicylic acid (150mg/Kg em 1,5 ml de 0,2N Hcl). In order to evaluate the pre-clinical toxicity, the animals were treated with oral doses according to the Guide for the accomplishment of studies on phytotherapic pre-clinical toxicity, following the current resolution. Complementary biochemical analyses were also carried out (leucogram, total cholesterol, triglicerids, glucose, alkaline phosphatase, TGP, TGO, creatinin, urea, potassium, uric acid, Gama GT) and microscopic and macroscopic analyses of the organs were performed as well, when necessary.

There is a paucity of studies, clinical and experimental, attesting to the benefit of cerebral perfusion pressure (CPP) directed pressor therapy following traumatic brain injury (TBI). The current study evaluates this therapy in a swine model of TBI and hypotension. Forty-five anesthetized and ventilated swine received TBI followed by a 45% blood volume bleed. After 1 h, all animals were resuscitated with 0.9% sodium chloride equal to three times the shed blood volume. The experimental group (PHE) received phenylephrine to maintain CPP > 80 mm Hg; the control group (SAL) did not. Outcomes in the first phase (n = 33) of the study were as follows: cerebro-venous oxygen saturation (S cvO2), cerebro-vascular carbon dioxide reactivity (δScvO2), and brain structural damage (β-amyloid precursor protein [βAPP] immunoreactivity). In the second phase (n = 12) of the study, extravascular blood free water (EVBFW) was measured in the brain and lung. After resuscitation, intracranial and mean arterial pressures were >15 and >80 mm Hg, respectively, in both groups. CPP declined to 64 ± 5 mm Hg in the SAL group, despite fluid supplements. CPP was maintained at >80 mm Hg with pressors in the PHE group. PHE animals maintained better ScvO2 (p < 0.05 at 180, 210, 240, 270, and 300 min post-TBI). At baseline, 5% CO2 evoked a 16 ± 4% increase in ScvO2, indicating cerebral vasodilatation and luxury perfusion. By 240 min, this response was absent in SAL animals and preserved in PHE animals (p < 0.05). Brain EVBFW was higher in SAL animals; however, lung EVBFW was higher in PHE animals. There was no difference in βAPP immunoreactivity between the SAL and PHE groups (p > 0.05). In this swine model of TBI and hypotension, CPP directed pressor therapy improved brain oxygenation and maintained cerebro-vascular CO2 reactivity. Brain edema was lower, but lung edema was greater, suggesting a higher propensity for pulmonary complications.

Traumatic brain injury (TBI) is a major problem with an estimated cost of $76 billion per year in the US alone. The Center for Disease Control and Prevention (CDC) documented 2.53 million TBI-related emergency department visits, with approximately 288,000 TBI-related hospitalizations and 56,800 TBI-related deaths in 2014 in the US. The lack of FDA-approved treatment strategies for TBI drives the need for novel therapeutic and preventative measures. In a quest to reduce TBI-related injuries and deaths, automotive companies have focused their efforts to make safer cars for both occupants and pedestrians. Computational finite element (FE) models have been used to advance research efforts in automotive safety systems engineering in hopes of ameliorating the burden caused by TBI. The current use of FE models in the automotive industry focuses on predicting stresses and strains that occur during the accident itself to predict primary injury. However, contemporary models lack the appropriate mechanical properties required to make accurate predictions of brain tissue deformation after injury and lack the ability to model secondary injuries such as cerebral edema (brain swelling). With cerebral edema being a major cause of death and disability after TBI, and with the pattern and magnitude of cerebral edema being dependent on the initiating strain field in brain tissue during TBI, automotive safety systems could be further improved if 1) FE head models contained more accurate mechanical properties and 2) if FE models could simulate secondary injuries such as cerebral edema. Therefore, the driving purpose of this thesis is two-fold: 1) to determine the mechanical properties of different regions of the brain and 2) to present a new computational methodology that allows for modeling of cerebral edema to better predict patient outcome following TBI. The use of FE models requires appropriate constitutive formulations and associated parameters to accurately model and predict the initial mechanical response of the brain to injury loading conditions. Since patient outcome is dependent on the resulting strain field within brain tissue post-injury, accurate modeling of brain tissue deformation is important for testing the efficacy of engineered automotive safety systems using FE simulations. To address this need, the first aim of this thesis employed an inverse FE approach to characterize mechanical properties of the human hippocampus (CA1, CA3, dentate gyrus), cortex white matter, and cortex gray matter. Anatomical regions were significantly different in their mechanical properties. Although no sex dependency was observed, there were trends indicating that some male brain regions were generally stiffer than corresponding female regions. In addition, mechanical properties were not dependent on age within the examined age range (4-58 years old). Ultimately, this study provides a structure-specific description of fresh human brain tissue mechanical properties, which will be an important step toward explicitly modeling the heterogeneity of brain tissue deformation during TBI using FE modeling. Fatal brain injuries may also result from physiological changes in the brain that occur after the primary injury that immediately occurs during head injury. Secondary injuries such as cerebral edema are associated with poor outcome. Despite the severe consequences of cerebral edema, its mechanism is not fully understood. The second aim of this thesis, therefore, was to elucidate the driving mechanism of cerebral edema by demonstrating that cleavage of intracellular fixed-charge density (FCD) reduces brain swelling pressure and to measure the FCD content of rat and pig brain tissue. Thin brain samples were placed into a confined pressure chamber, and FCD content was calculated from measured swelling pressure and the Gibbs-Donnan equation. We observed that cleavage of FCD using enzymes reduced swelling pressure in rat brain tissue samples and determined that pig cortex gray matter contains more FCD than pig cortex white matter. These results demonstrate that cerebral edema may occur in accordance with principles of triphasic swelling biomechanics and demonstrates the plausibility of computationally modeling cerebral edema with triphasic material formulations. Cerebral edema leads to increased intracranial pressure (ICP) as the brain swells within the fixed volume of the skull, and there is overwhelming evidence of ICP as a powerful predictor of patient outcome following TBI. Current industry standards of patient outcome evaluation use tissue-level metrics solely from primary injury such as maximum principal strain (MPS) or cumulative strain damage measure (CSDM), but these methods can be improved especially in regards to predicting mortality. Therefore, the third aim of this thesis was to develop a new FE head model and computational methodology incorporating triphasic swelling biomechanics to simulate brain swelling following impact to improve patient outcome predictions. Patient outcome was predicted by simulating swelling and calculating the resulting ICP, which is a strong indicator of patient mortality. Calculating ICP in addition to predicting primary injury metrics such as MPS and CSDM may allow automotive safety engineers to make better predictions of patient outcome following TBI so they can develop better safety systems. Another common indicator of poor outcome following TBI is acute subdural hematoma (ASDH). ASDH is an intracranial bleed that often results from TBI because of stretching and tearing of the bridging veins which causes blood to collect in the innermost layer of the dura. Despite the poor prognosis associated with the presence of ASDH following TBI, the mechanism as to why its presence is associated with a higher likelihood of death remains uncertain. Current state of the art FE head models used in automotive safety engineering efforts do not consider ASDH, which may drastically reduce their effectiveness in predicting patient outcome following TBI. Therefore, the fourth and final aim of this thesis was to incorporate ASDH into our FE head model of swelling and elucidate the underlying secondary brain injury mechanism of ASDH that contributes to increased mortality in hopes of increasing the efficacy of current FE models to predict patient outcome and ultimately design better safety systems. Using our novel FE head model and methodology from aim 3, we showed that the higher likelihood of death associated with the presence of ASDH may be caused by exacerbated ischemic injury which increases ICP, demonstrating that modeling of ASDH is necessary for accurately modeling patient outcome following TBI. Despite decades of TBI research and FE head model improvements, more work is required to enhance the biofidelity of these models to better predict patient outcome. The work in this thesis is important, as it introduces a new tool that will allow automotive safety engineers to incorporate cerebral edema and ASDH, both of which may drastically influence patient outcome following TBI, into models of head injury to allow for better predictions of patient outcome. It is hoped that the work in this thesis lays the foundation for future work that aids in the design of improved automotive safety systems that will save countless human lives.

Quantitative computertomographische Studie zu den pulmonalen Auswirkungen intramuskulär applizierten Xylazins beim Schaf Einleitung. α2-Agonisten wie z.B. Xylazin werden in der veterinärmedizinischen Praxis häufig zur Se-dierung eingesetzt. Dabei ist für das Schaf eine besonders ausgeprägte Sensibilität gegenüber Xylazin nachgewiesen. Bisher nur unzureichend untersucht wurde der Einfluss der Applikationsform des α2-Agonisten Xylazin (intravenöse versus intramuskuläre Injektion) auf den Ausprägungsgrad der entste-henden Lungenveränderungen. Ziele der Untersuchungen. Ziel der vorliegenden Arbeit war es, die Xylazin-induzierten pulmonalen Reaktionen nach intramuskulärer Applikation zu quantifizieren und mit den Auswirkungen einer intrave-nösen Gabe beim Schaf zu vergleichen. Um wissenschaftlich konsequent zu arbeiten, wurde weiterhin die Wirkung der in Xylazin-Präparaten enthaltenen sonstigen Bestandteile untersucht. Material und Methode. Als Studientiere wurden sieben weibliche Schafe der Rasse Merinoland zwei-malig in einem Abstand von acht Wochen untersucht. Bei diesen Tieren handelte es sich um die Scha-fe, welche in einem vorausgegangenen Projekt zu den pulmonalen Wirkungen von intravenös appliziertem Xylazin in identischer Dosierung am deutlichsten reagiert hatten. Nach Prämedikation der Tiere mit Midazolam (0,25 mg/kg KM) und Sufentanil (0,6 µg/kg KM) wurde die Narkose mit Propofol aufrechterhalten (5-10 mg/kg KM/h). Nach abgeschlossener Instrumentierung wurden die Schafe in Rückenlage im Computertomographen positioniert und mit einer inspiratorischen Sauerstoffkonzentration von 100 Vol.-% beatmet. Zur Reduktion lagerungsbedingter Atelektasen wurde vor Versuchsbeginn ein Recruit¬ment¬ma¬nö¬ver (druckkontrollierte Beatmung, inspiratorischer Spitzendruck 60 cmH2O, PEEP 40 cmH2O, Atemfrequenz 10/min, Dauer zwei Minuten) durchgeführt. Nach abgeschlossenem Recruitmentmanöver wurden die Schafe bis zum Ende des Versuchsabschnittes volumenkontrolliert beatmet (Atemzugvolumen 8 ml/kg KM, PEEP 10 cmH2O, Adjustierung der Atemfrequenz, Ziel endexspiratorische Kohlendioxidkonzentration etwa 4,5 Vol.-%). Im Versuchsabschnitt „i.m.“ wurde Xylazin intramuskulär in einer Dosierung von 0,3 mg/kg KM injiziert. 10 Minuten vor sowie 5, 15, 30 und 60 Minuten nach der Xylazin-Injektion wurden computertomographische Untersuchungen des Thorax durchgeführt. Im Versuchsabschnitt „Vehikel“ wurde den Schafen eine dem verwendeten Xylazin-Präparat analoge, jedoch Xylazin-freie Lösung intravenös appliziert (enthält 1 mg/ml des Konservierungsstoffs Methyl-para-hydroxybenzoat). Als Dosis wurde eine der Xylazin-Gabe entsprechende Dosis von 0,015 ml/kg KM gewählt. Zusätzlich wurde 45 Minuten nach Versuchsbeginn Xylazin® 2 % in einer Dosis von 0,3 mg/kg KM intravenös injiziert. Die computertomographischen Untersuchungen wurden 10 Minuten vor sowie 5, 15, 30 Minuten nach erfolgter Injektion des Vehikel-Präparates und 5 Minuten nach erfolgter Injektion von Xylazin® durchgeführt. Unter Anwendung der Extrapolationsmethode wurden mit der quantitativen computertomographischen Analyse jeweils das totale Lungenvolumen (Vtot), das totale Lungengewicht (Mtot) und der Anteil der nicht belüfteten Lungenmasse (% Mnon) bestimmt. Dabei galt ein Abfall im totalen Lungenvolumen als Nachweis für Atelektasen, ein Anstieg im totalen Lungengewicht war gleichbedeutend mit der Entstehung eines Lungenödems. Als klinisch relevant galt eine Zunahme der totalen Lungenmasse um 100 g. In beiden Versuchsabschnitten wurden mittels arterieller Blutgasanalysen zusätzlich der arterielle Sauerstoff- und Kohlenstoffdioxidpartialdruck (PaO2, PaCO2) erfasst. Ergebnisse. Vor der intramuskulären Xylazin-Gabe wurden folgende Medianwerte ermittelt: Vtot: 4220 ml, Mtot: 1280 g, % Mnon: 3 %, PaO2: 443 mmHg, PaCO2: 48 mmHg. Nach intramuskulärer Xylazin-Injektion zeigten sich die nachfolgenden statistisch signifikanten Maximaländerungen: Vtot-Abfall: 516 ml (Interquartilbereich 408-607), Mtot bzw. % Mnon-Zunahme: 108 g (Interquartilbereich 70-140) bzw. 15 % (Interquartilbereich 8-24) PaO2-Abfall: 280 mmHg (Interquartilbereich 200-346), PaCO2-Anstieg: 17 mmHg (Interquartilbereich 7-27). Die intramuskuläre Gabe von Xylazin verursachte im Vergleich zur intravenösen tendenziell, aber statistisch nicht signifikant, geringere Abnahmen im totalen Lungenvolumen sowie eine tendenziell, aber statistisch nicht signifikant geringere Zunahme im Anteil der nicht belüfteten Lungenmasse. Des Weiteren konnte ein statistisch signifikant geringerer Abfall im arteriellen Sauerstoffpartialdruck bei intramuskulär erfolgter Injektion nachgewiesen werden. Die Xylazin-induzierte Hypoxämie erreichte unter Beatmung mit 100 Vol.-% Sauerstoff auch nach intramuskulärer Gabe des α2-Agonisten im Mittel einen moderaten Ausprägungsgrad, wobei 50 % der Studientiere sogar eine schwere Belüftungsstörung zeigten (PaO2 < 100 mmHg). Entsprechend dem Schweregrad der durch den α2-Agonisten induzierten Belüftungsstörung trat eine Hyperkapnie auch nach intramuskulärer Xylazin-Gabe auf. Auch die korrespondierenden % Mnon-Zunahmen erreichten bei intramuskulärer Xylazin-Injektion neben der statistischen Signifikanz erhebliche klinische Relevanz. So waren im Mittel 18 % (Interquartilbereich 10-28) des Lungengewebes nach intramuskulärer Gabe des α2-Ago¬nis¬ten nicht belüftet. Bei jeweils 50 % der Tiere konnte für beide Applikationsformen ein klinisch relevantes Lungenödem nachgewiesen werden. Eine Reaktion der Versuchstiere auf die sonstigen im Xylazin-Präparat enthaltenen Bestandteile konnte ausgeschlossen werden. So konnte für keinen der untersuchten Parameter eine statistisch signifikante Änderung nach Injektion der Vehikel-Lösung nachgewiesen werden. Statistisch signifikante Zu- bzw. Abnahmen in den untersuchten Parametern konnten eindeutig der Wirkung des α2-Agonisten Xylazin zugewiesen werden. Schlussfolgerungen. Trotz quantitativ geringerer Ausprägung in den detektierten Änderungen von Vtot, PaO2 und % Mnon zeigten die Xylazin-induzierten pulmonalen Reaktionen bei der Mehrzahl der Studientiere auch nach intramuskulär erfolgter Applikation des α2-Agonisten erhebliche klinische Relevanz. Ein zeitlich verzögertes Eintreten im Vergleich zur intravenösen Gabe des α2-Agonisten konnte nur für die Formation des Xylazin-induzierten Lungenödems festgestellt werden. Analog zu den Ergebnissen des vorausgegangenen Projektes zur Wirkung von intravenös verabreichtem Xylazin, kann das morphologische Bild der Xylazin-induzierten Lungenveränderungen durch eine Koexistenz von Atelektasen und Lungenödem beschrieben werden. Derzeit konnte noch kein logisches Muster gefunden werden, dass die interindividuelle Variabilität in der Reaktion auf Xylazin beim Schaf aufzuklären vermag. Ebenso ist der Erkenntnisstand bezüglich einer möglicherweise vorhandenen Rasseabhängigkeit bis dato nicht ausreichend, um im Vorfeld die Sensibilität gegenüber Xylazin bei einem Schaf abschätzen zu können. Demzufolge muss beim Schaf auf der Grundlage der vorliegenden Ergebnisse im Einzelfall auch nach einer intramuskulären Xylazin-Gabe mit einer Dosierung von 0,3 mg/kg KM von schwerwiegenden Lungenveränderungen ausgegangen werden. Sofern Schafe als Tier-Modell in der experimentellen Lungenforschung verwendet werden, sollte aufgrund der Gefahr von fehlerhaften Forschungsergebnissen sowohl auf den intramuskulären Einsatz von Xylazin zur Prämedikation verzichtet werden als auch auf die intravenöse Verabreichung des α2-Agonisten als Narkosebestandteil. Um in der Praxis zukünftig unnötiges Leiden oder gar Versterben von Tieren verhindern zu können, muss die Problematik der Xylazin-induzierten Lungenveränderungen beim Schaf weiter verfolgt und näher erforscht werden.

Le syndrome de détresse respiratoire aiguë (SDRA) se développe suite à une atteinte pulmonaire lésionnelle, induisant un œdème et une inflammation excessive, généralement suivis d’une réparation atypique menant à la fibrose. Malgré de signifiants progrès dans les traitements, la mortalité reste élevée : ~ 40 %. Mon hypothèse de travail est que l’atténuation de l’œdème ou de la réponse inflammatoire pourrait freiner le développement ou la sévérité de la phase exsudative. Nous avons évalué cette hypothèse à l’aide d’un modèle de phase exsudative du SDRA, i.e. instillation intra-trachéale de bléomycine, chez les souris.  La modulation des fluides alvéolaires est étudiée avec des souris transgénique (Tg) pour le canal ENaC, qui sont sensibles à la formation d’un œdème. Cependant, ces souris Tg ne sont pas plus sensibles au développement de la phase exsudative en condition lésionnelle (bléomycine). Nous avons déterminé par une étude électrophysiologique des cellules épithéliales alvéolaires de type II (AT II) que ce n’est pas lié à une inhibition par la bléomycine de la fonction du canal ENaC.  Le traitement de la réponse inflammatoire associée au SDRA par des glucocorticoïdes est une thérapie potentielle mais controversée. Les glucocorticoïdes dans notre modèle murin ne réduisent pas la sévérité des lésions. Nous avons pu déterminé lors d’expériences in vitro que ce serait dû à une réduction de la capacité de réparation des AT II. En résumé :  La modulation du canal ENaC ne modifie pas le développement de la phase exsudative, suggérant que la régulation de l’œdème n’est pas suffisante pour modifier l’évolution du SDRA.  La modulation de l’inflammation par les glucocorticoïdes est ineffective, possiblement à cause d’une altération de la réparation. Mon étude suggère que le traitement de la phase exsudative du SDRA est complexe. En effet, la régulation de l’œdème ou de l’inflammation de façon isolée ne peut pas modifier l’évolution du SDRA. L'hétérogénéité des sources du SDRA et la redondance des mécanismes cellulaires impliqués dans l’évolution des lésions pulmonaires suggèrent que le traitement nécessitera une approche visant plusieurs cibles mécanistiques afin d’en accélérer la résolution. / Although much has been learned about the mechanisms leading to acute respiratory distress syndrome (ARDS), mortality remains high: ~ 40%. This syndrome is associated with lung injury where alveolar edema and excessive inflammatory response can progress to abnormal epithelial repair and fibrosis. The hypothesis of the work presented in this thesis is that attenuation of edema or of the inflammatory response in the initial stage of the acute lung injury would decrease the severity of injury. I evaluated this hypothesis in an ARDS acute phase, modeled by an intratracheal instillation of bleomycin in mice, using two distinct experimental strategies.  The importance of edema clearance was studied in a transgenic (Tg) ENaC mouse, a mouse known to be sensitive to the formation of edema. However, our results show that these Tg mice were not more susceptible to the development of the ARDS acute phase induced by bleomycin. Furthermore, we have been able to show that bleomycin itself did not interfere with the ENaC channel function of alveolar epithelial cells type II (AT II).  The treatment of the inflammatory response associated with ARDS by glucocorticoid therapy is subject to controversy. In our mouse model, glucocorticoids decrease the level of cytokine in the alveolar milieu but did not decrease the severity of lung injury. Using in vitro experiments, we show that this lack of response could be secondary to the impact of the treatment on the epithelial repair capacity of AT II. In summary:  The ENaC channel expression did not have an impact on the development of the exudative phase, suggesting that the regulation of edema is not sufficient to alter the course of ARDS.  The modulation of inflammation by glucocorticoids was ineffective, possibly because of impaired repair of the epithelium. These results suggest that the control of edema or inflammation separately does not modify the evolution of lung injury. The heterogeneity of the ARDS origins and the redundancy of cellular mechanisms involved in lung injury will require therapy aimed at multiple pathophysiological targets to permit the resolution of lung injury.

La détérioration de la barrière hémato rétinienne et l'oedème maculaire consécutif est une manifestation cardinale de la rétinopathie diabétique (RD) et la caractéristique clinique la plus étroitement associée à la perte de la vue. Alors que l'oedème maculaire affecte plus de 25% des patients souffrant de diabète, les modalités de traitement actuellement disponibles tels que les corticostéroïdes administrés localement et les thérapies anti-VEGF récemment approuvés présentent plusieurs inconvénients. Bien que le lien entre une rupture de l’unité neuro-vasculaire et la pathogénèse de la RD ait récemment été établi, l’influence de la signalisation neuro-vasculaire sur la vasculopathie oculaire diabetique a jusqu’à présent reçu peu d’attention. Ici, à l’aide d’ètudes humaines et animales, nous fournissons la première preuve du rôle essentiel de la molécule de guidage neuronale classique Sémaphorine 3A dans l’instigation de la perméabilité vasculaire maculaire pathologique dans le diabète de type 1. L’étude de la dynamique d’expression de Sémaphorine 3A révèle que cette dernière est induite dans les phases précoces hyperglycèmiques du diabète dans la rétine neuronale et participe à la rupture initiale de la fonction de barrière endothéliale. En utilisant le modèle de souris streptozotocine pour simuler la rétinopathie diabétique humaine, nous avons démontré par une série d’approches analogue que la neutralisation de Sémaphorine 3A empêche de façon efficace une fuite vasculaire rétinienne. Nos résultats identifient une nouvelle cible thérapeutique pour l’oedème maculaire diabétique en plus de fournir d’autres preuves de communication neuro-vasculaire dans la pathogènese de la RD. / The deterioration of the blood retinal barrier and consequent macular edema is a cardinal manifestation of diabetic retinopathy (DR) and the clinical feature most closely associated with loss of sight. While macular edema affects over 25% of patients suffering from diabetes, currently available treatment modalities such as locally administered corticosteroids and recently approved anti-VEGF therapies, present several drawbacks. Although recent insight on the pathogenesis of DR points to a breakdown in the neurovascular unit, neurovascular cross-talk and its influence on diabetic ocular vasculopathy has thus far received limited attention. Here we provide the first evidence from both human and animal studies for the critical role of the classical neuronal guidance cue Semaphorin3A in instigating pathological macular vascular permeability in type I diabetes. Investigation of the dynamics of expression reveal that Semaphorin3A is induced in the early hyperglycemic phases of diabetes within the neuronal retina and precipitates initial breakdown of endothelial barrier function. Using the streptozotocin mouse model as a proxy for human diabetic retinopathy, we demonstrate by a series of orthogonal approaches (gene silencing or treatment with soluble Neuropilin-1 employed as a Semaphorin3A trap), that neutralization of Semaphorin3A efficiently prevents retinal vascular leakage. Our findings identify a new therapeutic target for DME and provide further evidence for neurovascular cross-talk in pathogenesis of DR.