Background: There are many factors are known to increase the risk of sternal wound infection (SWI), some studies have reported that nickel is a risk factor for SWI. Titanium wires have only been used as an alternative to steel wires in patients with known allergy to nickel. However, there is a paucity of literature regarding the safety of using titanium wires compared to that on the safety of steel wires for sternum closure after cardiac surgery. Therefore, this study aimed to demonstrate the non-inferiority of titanium wires, even in patients without a known allergy. Methods: A total of 322 Patients who underwent elective full median sternotomy were randomly assigned to sternal closure either by titanium wires (n=161) or by stainless steel wires. Results: 14 patients had sternal instability, six (3.7%) patients in the titanium group and eight (5%) patients in the stainless steel group (p = 0.585). There was no statistically significant difference between both groups in terms of postoperative wound infection (p=0.147). Patients in the titanium group experienced statistically significant lower postoperative pain than those in the stainless steel group (p = 0.024). The wire type was not an independent risk factor for SI, as shown by univariate and logistic regression analyses. Conclusion: Titanium wires are a good alternative and have been proven to be safe and effective for sternal closure. The surgeon should be aware of the possibility of developing an allergic reaction to the wires especially in patients with previous multiple allergic histories.:Table of Contents 1. Background 5 1.1. Anatomy of the sternum 5 1.2. Blood Supply of the Sternum 6 1.3. Basis and phases of acute Wound healing 7 1.4. Biomechanics of the sternum 7 1.5. Post-sternotomy complications 8 1.5.1. Dehiscence and sternal instability 8 1.5.2. Mediastinitis and Deep Sternal Wound Infection 10 1.5.3. Risk factors 12 1.5.4. Diagnosis 12 1.5.5. Bacteriology of Sterno-Mediastinal fluid and tissues 14 1.5.6. Osteomyelitis 14 1.6. Sternal fixation and Wiring Techniques 15 1.7. Overview of sternal closure techniques in Germany 16 1.7.1 Sternal closure Technique in Heart Center Dresden. 17 1.8. ASEPSIS SCORE 17 1.9. NICKEL Allergy/Suture materials and biocompatibility 19 1.10 Nickel allergy and cardiac surgery 20 1.11 Titanium Allergy 21 1.12. Pathophysiology of Metal Hypersensitivity Reactions 22 1.13. The hypothesis of the study 24 2. Materials and methods 25 2.1. Study Population 25 2.1.1. Inclusion criteria 25 2.1.2. Exclusion criteria 25 2.2. Intervention 25 2.3. Control 26 2.4. Outcome 26 2.5. Time 26 2.6. Sample Size calculation 26 2.7. Sternal closure technique 27 2.8. Handling of the wire 28 2.9. Blinding and randomization technique 29 2.10. Data collection and documentation 29 2.11. Statistics 29 3. Results 31 3.1. Preoperative parameters 31 3.1.1. Entire group 31 3.1.2. Group comparison 32 3.2. Intraoperative parameters 34 3.2.1. Entire group 34 3.2.2. Group comparison 34 3.3. Postoperative parameters 35 3.3.1. Entire group 35 3.3.2. Group comparison 36 3.4. Incidence of postoperative sternal instabilities 38 3.5. Univariate analysis 38 3.5.1. Pre-operative 39 3.5.2. Intra-operative 40 3.5.3. Post-operative 40 3.5.4. Statistically significant data 41 3.5.5. Descriptive presentation of the subgroup analysis (Sternal Instability, wire Classification) 41 3.5.6. Logistic regression 43 3.6. Summary / key result 44 4. Discussion 45 4.1. Sternal Instability 46 4.2. BMI “Obesity” 47 4.3. Wound Infection /ASEPSIS Score 48 4.4. Postoperative Pain 49 4.5. Type of the Wire 51 4.6. The Rising Potential Impact of Metal Hypersensitivity on other specialities 51 4.7. Limitation of the study 52 4.7. Conclusion 55 5. Summary 56 6. Zusammenfassung 58 7. List of figure 60 8. List of tables 60 Bibliography 64

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A range of behavioral strategies and sensory abilities allow animals to minimize costs involved in the search for food. Among the factors involved in the variation of foraging costs, the availability of resources represents a central role and it is recognized for modulating the animal home range. Some species of termites can exhibit characteristics that make the foraging process even more expensive. Species belonging to the genus Nasutitermes, for example, have an extra cost in foraging: in addition to build a network of tunnels to access resources, they have a large number of soldiers, a caste trophically dependent. In the present study: (i) we evaluated the foraging pattern in Nasutitermes aff. coxipoensis (Termitidae: Nasutitermitinae), including the searching strategy and the role of soldiers; and (ii) we analyzed whether colonies of this species responds to variations in the availability of food resources. Manipulative experiments were conducted in the field and in the laboratory to analyze the pattern of foraging in N. aff. coxipoensis. For this, 35 nests were transplanted into areas of dunes in Pirambu-SE. Seven plots were established in a continuous increament in the density of resources (sugarcane baits). Laboratory tests were conducted to examine the role of chemical signals (eg. trail pheromone) present in the sternal gland of workers and soldiers. During 10 consecutive days it was measured: the number of trails and tunnels, their total length, number of branches and the tunneling speed (cm/day). Data were analyzed using generalized linear models and mixed linear models. Nasutitermes aff. coxipoensis showed mainly nocturnal foraging. Soldiers were the first individuals to start the foraging, however, in established trails, the number of workers were always higher than soldiers. The number of active trails remained constant over the observation period, while the number of tunnels increased. In groups of soldiers and workers, the workers chose to follow the trail signals of soldiers. The number of trails, the total length and their branches decreased with increment of resource availability. The conversion of trails in tunnels increased in areas with higher resource density. Our results suggest that the costs involved in the production of soldiers in N. aff. coxipoensis seem to be compensated by their decisive role during the foraging process. Colonies of this species seem to optimize their foraging through a combined strategy of constructing trails and tunnels. In places with low resource availability, termites forage mainly on trails, avoiding to convert trails in tunnels. This strategy has not yet been reported in the literature. Thus, N. aff. coxipoensis presents strategies in order to optimize the foraging, minimizing costs involved in this process. These results can contribute to the key question about the evolution of termite foraging behavior, as well as to understand the mechanisms involved in the distribution patterns and structuring communities of these insects. / Uma gama de estratégias comportamentais e habilidades sensoriais permite aos animais minimizar os custos envolvidos na busca por alimento. Dentre os fatores envolvidos na variação dos custos de forrageio, a disponibilidade de recursos representa um papel central e é reconhecida por modular as áreas de uso dos animais. Algumas espécies de cupins exibem características que podem tornar o processo de forrageio ainda mais oneroso. Espécies do gênero Nasutitermes, por exemplo, apresentam gastos extras no forrageio, uma vez que além de construírem uma rede de túneis para acessar os recursos, ainda apresentam um elevado número de soldados, indivíduos troficamente dependentes. No presente estudo, avaliamos (i) o padrão de forrageio em Nasutitermes aff. coxipoensis (Termitidae: Nasutitermitinae), incluindo as estratégias de busca e o papel dos soldados; e (ii) analisamos se colônias desta espécie respondem à variação na disponibilidade de recursos. Experimentos manipulativos foram conduzidos em campo e em laboratório a fim de analisar o padrão de forrageio de N. aff. coxipoensis. Para isso, 35 ninhos foram transplantados em áreas de dunas, em Pirambu- SE. Foram estabelecidas sete parcelas em um contínuo de aumento da densidade de recursos (iscas de cana-de-açúcar). Testes em laboratório foram realizados a fim de analisar o papel dos sinais químicos (ex. feromônio de trilha) presente na glândula esternal de operários e soldados. Durante 10 dias consecutivos foram quantificados: o número de trilhas e de túneis, o comprimento total, o número de ramificações destes e a velocidade de construção dos túneis. Os dados foram analisados utilizando-se modelos lineares generalizados e modelos mistos. Nasutitermes aff. coxipoensis apresentou forrageio principalmente noturno. Soldados foram os primeiros indivíduos a iniciarem o forrageio, no entanto, em trilhas já estabelecidas, o número de operários foi sempre maior do que o de soldados. O número de trilhas ativas permaneceu constante ao longo do período de observação, enquanto o número de túneis aumentou de forma gradativa. Em grupos compostos por soldados e operários, os operários preferiram seguir os sinais de trilha dos soldados. O número de trilhas, o comprimento total e suas ramificações reduziram com o aumento da disponibilidade de recursos. A conversão de trilhas em túneis aumentou em locais com maior densidade de recursos. Nossos resultados sugerem que os custos envolvidos na produção de soldados de Nasutitermes aff. coxipoensis parecem ser compensados pelo seu papel decisivo no forrageio. Colônias desta espécie parecem otimizar o forrageio através de uma estratégia combinada de formação de trilhas e túneis. Em locais com baixa disponibilidade de recursos os cupins forrageiam preferencialmente em trilhas, evitando a conversão destas em túneis. Tal estratégia, ainda não foi relatada na literatura. Assim, N. aff. coxipoensis apresenta estratégias para otimização do forrageio, minimizando os custos envolvidos nesse processo. Os resultados deste estudo podem contribuir para a investigação de questões sobre evolução do comportamento de forrageio de cupins, assim como para desvendar os mecanismos envolvidos nos padrões de distribuição e estruturação de comunidades desses insetos.

Breathing is a vital phenomenon that implies synergy of various anatomical structures that constitute the thorax. Joint physiology remains a relatively poorly-known component of the overall thorax physiology. Quantitative literature related to in vivo thorax kinematics during breathing is scarce. The present work focuses specifically on developing and applying a methodology to reach this goal. The developed method combined processing of CT data obtained at different lung volumes and infographic techniques. Detailed ranges of motion (ROMs) and axes of movement (mean helical axes, MHAs) were obtained at costovertebral joints in 12 asymptomatic subjects; rib ROMs gradually decrease with increasing rib number; lung volume and rib level have a significant influence on rib ROM; MHAs did not differ between rib levels. In addition, the method was applied on a sample of 10 patients with cystic fibrosis. The pathological condition significantly influenced CVJ ROMs while the orientation of the MHAs did not differ. Finally, the sternal displacement, sternal angle variations and sternocostal joints (SCJ at rib1 to 7) kinematics during breathing motion were analyzed. Rib ranges of motion relative to sternum decreased with increasing rib number similarly to CVJ. Orientation of the MHAs did not differ between SCJ levels. A significant linear correlation was demonstrated between sternum vertical displacement and rib ranges of motion at both CVJ and SCJ. The present work substantially contributes to 3D modelling of human thorax in breathing at a joint level both qualitatively and quantitatively. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished