[ES] El infarto agudo de miocardio (IAM) es una de las principales causas de morbilidad y mortalidad en los países desarrollados. A lo largo de los últimos años se ha visto que la respuesta inflamatoria que ocurre tras desencadenarse el IAM es muy importante en el desarrollo clínico de esta patología. Si se produce una respuesta inflamatoria exacerbada aumenta el riesgo de remodelado cardiaco adverso y fallo cardiaco, pero el hecho de que no se desencadene la respuesta inflamatoria también tiene consecuencias negativas. Debido a la importancia de la respuesta inflamatoria en el IAM, recientemente se han intentado desarrollar terapias dirigidas frente componentes celulares o moleculares que participan en esta respuesta. Dentro de estas terapias, la terapia celular con células mesenquimales estromales (MSC) se ha postulado como un buen candidato. Las MSC se caracterizan fundamentalmente por su capacidad inmunomoduladora, lo que ha conducido a su empleo como agentes terapéuticos en diferentes enfermedades que cursan con procesos inflamatorios. Sin embargo, a lo largo de los últimos años, numerosos estudios han mostrado que el efecto terapéutico de las MSC está mediado fundamentalmente por las vesículas extracelulares (EVs) que liberan. Estas EVs recapitulan los efectos terapéuticos de las células de origen, por lo que también presentan efectos inmunomoduladores. El empleo de las EVs de MSC como agentes terapéuticos presenta ventajas respecto al uso de las MSC como, por ejemplo, una mayor bioseguridad. No obstante, el uso clínico de las EVs todavía tiene que hacer frente a retos como la obtención de grandes cantidades de EVs que constituyan un producto clínico estable y homogéneo. En este trabajo se ha querido evaluar, por un lado, si las EVs obtenidas de diferentes biopsias de la misma fuente tisular de MSC pueden constituir un producto biológico homogéneo que presente las mismas características y funcionalidad. Por otro lado, se ha evaluado si estas EVs se pueden emplear como agente terapéutico frente a la respuesta inflamatoria que se desencadena tras el IAM. Para ello se ha estudiado el efecto inmunomodulador de las EVs sobre células del sistema inmune, fundamentalmente macrófagos, in vitro y en un modelo in vivo de IAM en ratas. Los resultados mostraron que las EVs favorecen la diferenciación de los macrófagos M1 proinflamatorios hacia un fenotipo similar al M2, aumentando la expresión de marcadores M2 y reduciendo la secreción de citocinas proinflamatorias. Además, las EVs promovieron la activación de neutrófilos in vitro y la reducción de su estrés oxidativo. La administración de EVs en ratas sometidas a IAM amortiguó la caída de la función cardiaca y limitó la extensión de la zona infartada a los 7 y 21 días postinfarto. Las EVs también redujeron el número de macrófagos y neutrófilos proinflamatorios dentro de la zona infartada, favoreciendo la resolución de la inflamación. En conclusión, las EVs empleadas en este trabajo han demostrado ser un producto biológico estable con independencia de la biopsia de la que proceden, y han demostrado ser capaces de ejercer respuestas pro-resolutivas eficaces en un modelo de isquemia miocárdica, lo que las convierte en potenciales agentes terapéuticos para tratar la inflamación en el IAM. / [CA] L'infart agut de miocardi (IAM) és una de les principals causes de morbiditat i mortalitat als països desenvolupats. Al llarg dels darrers anys s'ha vist que la resposta inflamatòria que passa després de desencadenar-se l'IAM és molt important en el desenvolupament clínic d'aquesta patologia. Si es produeix una resposta inflamatòria exacerbada augmenta el risc de remodelat cardíac advers i fallada cardíaca, però el fet que no es desencadeni la resposta inflamatòria també té conseqüències negatives. A causa de la importància de la resposta inflamatòria a l'IAM, recentment s'han intentat desenvolupar teràpies dirigides davant de components cel·lulars o moleculars que participen en aquesta resposta. Dins aquestes teràpies, la teràpia cel·lular amb cèl·lules mesenquimals estromals (MSC) s'ha postulat com un bon candidat. Les MSC es caracteritzen fonamentalment per la seva capacitat immunomoduladora, cosa que ha conduït a la seva ocupació com a agents terapèutics en diferents malalties que cursen amb processos inflamatoris. Tot i això, al llarg dels últims anys, nombrosos estudis han mostrat que l'efecte terapèutic de les MSC està intervingut fonamentalment per les vesícules extracel·lulars (EVs) que alliberen. Aquestes EVs recapitulen els efectes terapèutics de les cèl·lules dorigen, per la qual cosa també presenten efectes immunomoduladors. L'ús de les EVs de MSC com a agents terapèutics presenta avantatges respecte a l'ús de les MSC com, per exemple, una bioseguretat més gran. Tot i això, l'ús clínic de les EVs encara ha de fer front a reptes com l'obtenció de grans quantitats d'EVs que constitueixin un producte clínic estable i homogeni. En aquest treball s'ha volgut avaluar, d'una banda, si les EV obtingudes de diferents biòpsies de la mateixa font tissular de MSC poden constituir un producte biològic homogeni que presenti les mateixes característiques i funcionalitat. D'altra banda, s'ha avaluat si aquestes EVs es poden fer servir com a agent terapèutic davant de la resposta inflamatòria que es desencadena després de l'IAM. Per això s'ha estudiat l'efecte immunomodulador de les EV sobre cèl·lules del sistema immune, fonamentalment macròfags, in vitro i en un model in vivo d'IAM en rates. Els resultats van mostrar que les EVs afavoreixen la diferenciació dels macròfags M1 proinflamatoris cap a un fenotip similar al M2, augmentant l'expressió de marcadors M2 i reduint la secreció de citocines proinflamatòries. A més, les VE van promoure l'activació de neutròfils in vitro i la reducció del seu estrès oxidatiu. L'administració d'EVs en rates sotmeses a IAM va esmorteir la caiguda de la funció cardíaca i va limitar l'extensió de la zona infartada als 7 i 21 dies postinfart. Les EVs també van reduir el nombre de macròfags i neutròfils proinflamatoris dins de la zona infartada, afavorint la resolució de la inflamació. En conclusió, les EVs emprades en aquest treball han demostrat ser un producte biològic estable amb independència de la biòpsia de què procedeixen, i han demostrat ser capaços d'exercir respostes pro-resolutives eficaces en un model d'isquèmia miocàrdica, cosa que les converteix en agents terapèutics potencials per tractar la inflamació a l'IAM. / [EN] Acute myocardial infarction (AMI) is one of the main causes of morbidity and mortality in developed countries. Over the last few years, it has been shown that the inflammatory response that occurs after AMI is triggered is very important in the clinical development of this pathology. If an exacerbated inflammatory response occurs, the risk of adverse cardiac remodeling and heart failure increases, but failure to trigger the inflammatory response also has negative consequences. Because of the importance of the inflammatory response in AMI, recent attempts have been made to develop therapies that target cellular or molecular components involved in this response. Within these therapies, cell therapy with mesenchymal stromal cells (MSC) has been postulated as a good candidate. MSC are mainly characterized by their immunomodulatory capacity, which has led to their use as therapeutic agents in different diseases involving inflammatory processes. However, in recent years, numerous studies have shown that the therapeutic effect of MSCs is mainly mediated by the extracellular vesicles (EVs) they release. These EVs recapitulate the therapeutic effects of the cells of origin and therefore also have immunomodulatory effects. The use of MSC-EVs as therapeutic agents has advantages over the use of MSC, such as increased biosafety. However, the clinical use of EVs still faces challenges such as obtaining large quantities of EVs that constitute a stable and homogeneous clinical product. The aim of this study was to evaluate, on the one hand, whether EVs obtained from different biopsies of the same MSC tissue source can constitute a homogeneous biological product with the same characteristics and functionality. On the other hand, we have evaluated whether these EVs can be used as a therapeutic agent against the inflammatory response triggered after AMI. To this end, the immunomodulatory effect of EVs on immune system cells, mainly macrophages, was studied in vitro and in an in vivo model of AMI in rats. The results showed that EVs favored the differentiation of proinflammatory M1 macrophages towards an M2-like phenotype, increasing the expression of M2 markers and reducing the secretion of proinflammatory cytokines. In addition, EVs promoted the activation of neutrophils in vitro and the reduction of their oxidative stress. The administration of EVs in rats subjected to AMI blunted the decline in cardiac function and limited the extent of the infarct zone at 7- and 21-days post-infarction. EVs also reduced the number of proinflammatory macrophages and neutrophils within the infarct zone, favoring the resolution of inflammation. In conclusion, the EVs used in this work have been shown to be a stable biological product regardless of the biopsy from which they are derived and have been shown to be able to exert effective pro-resolving responses in a model of myocardial ischemia, making them potential therapeutic agents to treat inflammation in AMI. / Amaro Prellezo, E. (2024). Las vesículas extracelulares derivadas de células mesenquimales estromales de pulpa dental como producto terapéutico frente a la respuesta inmune que se desencadena tras el infarto agudo de miocardio [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202973

Stimulating lymphocytes with Ifn-γ, anti-CD3, and interleukin-2 promotes the proliferation of a cell population coexpressing T-lymphocyte surface antigens such as CD3, CD8a, and CD25 as well as natural killer cell markers such as NK1.1, CD49, and CD69. These cells, referred to as cytokine-induced killer cells (CIKs), display cytotoxic activity against tumour cells, even without prior antigen presentation, and offer a new cell-based approach to the treatment of malignant diseases. Because CIKs are limited in vivo, strategies to optimize in vitro culture yield are required. In the last 10 years, mesenchymal stem cells (MSCs) have gathered considerable attention. Aside from their uses in tissue engineering and as support in haematopoietic stem cell transplantations, MSCs show notable immunomodulatory characteristics, providing further possibilities for therapeutic applications. In this study, we investigated the influence of murine MSCs on proliferation, phenotype, vitality, and cytotoxicity of murine CIKs in a coculture system. We found that CIKs in coculture proliferated within 7 days, with an average growth factor of 18.84, whereas controls grew with an average factor of 3.7 in the same period. Furthermore, higher vitality was noted in cocultured CIKs than in controls. Cell phenotype was unaffected by coculture with MSCs and, notably, coculture did not impact cytotoxicity against the tumour cells analysed. The findings suggest that cell–cell contact is primarily responsible for these effects. Humoral interactions play only a minor role. Furthermore, no phenotypical MSCs were detected after coculture for 4 h, suggesting the occurrence of immune reactions between CIKs and MSCs. Further investigations with DiD-labelled MSCs revealed that the observed disappearance of MSCs appears not to be due to differentiation processes.

A artrose, também chamada de osteoartrose ou osteoartrite (OA), é a terceira doença de maior incidência no Mundo. Nesse trabalho, buscou-se criar uma lesão osteocartilaginosa em joelhos de ratos Wistar machos com seis meses de vida, objetivando constituir um modelo animal para estudo da OA humana e, a partir desse modelo, avaliar biomateriais de forma isolada ou associados entre si e avaliados quanto à sua segurança biológica e potencial de reparação tecidual. Além disto, foi analisado o efeito reparador de células-tronco mesenquimais da polpa do dente de leite humano (MSC) isoladamente e em associação com o biomaterial formado por: Titânio + Poli Vinil Álcool + Ac. Hialurônico, nesse estudo denominado de TRIGEL (TRG). O Ac. Hialurônico (HA), por suas propriedades visco elásticas, o pó de Titânio (Ti), devido às suas propriedades biológicas únicas de ostoeintegração e o polímero Poli Vinil Álcool (PVA), com suas propriedades hidrofílicas, promovendo a formação do Hidrogel, os quais associados entre si formam um compósito, o TRG, que foi aplicado sobre uma lesão padrão no joelho da pata pélvica direita de ratos Wistar machos de seis meses de idade. Para a obtenção da lesão padrão, os animais foram divididos em três grupos de cincoanimais e cada grupo foi submetido a uma intervenção cirúrgica em seus joelhos direitos, utilizando três técnicas cirúrgicas diferentes, a saber: Grupo (I): Remoção cirúrgica dos meniscos medial e lateral mais perfuração do platô tibial seguido da aspiração da medula óssea através dessa perfuração por meio de seringa e agulha. Grupo (II): Remoção dos meniscos mais perfuração, sem aspiração, Grupo (III): Apenas a perfuração. Todos os animais foram autopsiados após 30 dias. Os joelhos dos quinze animais que constituíam os três grupos foram devidamente catalogados e enviados para a empresa Histotech, para a confecção das lâminas, tendo sido eleito, por análise histológica, o Grupo (I), por demonstrar menor reparo tecidual espontâneo. Em tese, o TRG teria as seguintes propriedades: Uma fonte de reparação tecidual (visco terapia) dada pelo HA e a capacidade amortecedora e carreadora de células-tronco do polímero PVA, que se hidrata, formando o hidrogel. O Ti, pela sua propriedade de osteointegração formaria um tampão sobre as áreas de matriz óssea exposta o que possibilitaria o afluxo de novos condrócitos, que também pode ocorrer pela ação das células-tronco. Livrar a superfície articular das áreas com exposição da matriz óssea é fundamental para o bloqueio das proteases que perpetuam a fisiopatologia da OA. Após tratamento estatístico dos diversos ensaios, utilizando-se os diversos biomateriais no tratamento da lesão, o TRG foi o biomaterial que apresentou o melhor resultado de força entre os grupos. No estudo histológico, foi evidenciada a presença de tecido cartilaginoso supra- lesional, o que só ocorreu nos animais dos grupos que receberam: apenas TRG, TRG associado com células-tronco e aquele que recebeu apenas MSCs. No entanto, mais estudos, com animais de maior porte e mais velhos, devem ser realizados para melhor analisar a segurança e o potencial terapêutico do compósito Trigel. / Osteoarthritis, or osteoarthritis (OA) is the third most debilitating disease in the world. In this study, we attempted to create an osteocartilaginous lesion in the knees of six months old male Wistar rats, aiming to constitute an animal model for the study of human OA and to use this model to evaluate the therapeutic potential of biomaterials, which are already well known for their biocompatibility properties in the clinical practice. The biomaterials were used in isolation or associated with each other and then evaluated for their biological safety and tissue repair capacity. Mesenchymal stem cells, obtained from human dental pulp from deciduous teeth (MSC) were evaluated alone and in association with the biomaterial formed by: Titanium + Poly Vinyl Alcohol + Ac. Hyaluronic, here called TRIGEL (TRG). Due to its visco-elastic properties, the Ti powder, due to its unique biological properties of ostointegration and the polymer PVA, with its hydrophylic properties, forming a hydrogel, were associated to form the composite named TRIGEL, (TRG), which was applied to a standard knee injury of the right hind leg of male Wistar rats. In order to elect the standard lesion, the animals were divided into three groups with five animals each and each group underwent a surgical intervention in their right knees, with three different surgical techniques being applied, namely: Group (1): Surgical removal ofmedial and lateral meniscus plus perforation of the tibial plateau, followed by aspiration of the bone marrow through this perforation using syringe and needle. Group (2): Removal of the meniscus plus perforation, without aspiration, Group (3): Drilling only. All groups were autopsied 30 days after the procedure and all groups were autopsied at 30 days post-procedure. The knees of the 15 animals that constituted the three groups were analyzed histologically and Group (1) (meniscus removed, perforated and aspirated), was elected as the standard lesion since it demonstrated less spontaneous tissue repair. TRG has the following properties: HA is used as a source of tissue repair (visco therapy) and hydration of the polymer; PVA, forms a hydrogel\", with damping action and as a stem cells carrier, whereas Ti was used due to its ósseo-integration, which would allow coating of the exposed bone matrix and this intra-osseous osteo-integration response would form an intercalating buffer. The healthy cartilage surfaces around this structural buffer would allow the reception of new chondrocytes or the action of the cells on TRG properties. Freeing the articular surface of the areas with bone matrix exposure is critical for blocking the proteases that perpetuate the pathophysiology of OA. In the various biomaterial tests in the treatment of the standard lesions, TRG was statistically shown to be the one that better mimicked the non-injured group. The histological study demonstrated the presence of a supra-lesional cartilagenous tissue, which only occurred in the groups which received: only TRG, mesenchymal stem cells associated with TRG and that which received only MSCs. However, further studies with larger and older animals should be pursued to better assess the safety and therapeutic potential of the Trigel composite.

A artrose, também chamada de osteoartrose ou osteoartrite (OA), é a terceira doença de maior incidência no Mundo. Nesse trabalho, buscou-se criar uma lesão osteocartilaginosa em joelhos de ratos Wistar machos com seis meses de vida, objetivando constituir um modelo animal para estudo da OA humana e, a partir desse modelo, avaliar biomateriais de forma isolada ou associados entre si e avaliados quanto à sua segurança biológica e potencial de reparação tecidual. Além disto, foi analisado o efeito reparador de células-tronco mesenquimais da polpa do dente de leite humano (MSC) isoladamente e em associação com o biomaterial formado por: Titânio + Poli Vinil Álcool + Ac. Hialurônico, nesse estudo denominado de TRIGEL (TRG). O Ac. Hialurônico (HA), por suas propriedades visco elásticas, o pó de Titânio (Ti), devido às suas propriedades biológicas únicas de ostoeintegração e o polímero Poli Vinil Álcool (PVA), com suas propriedades hidrofílicas, promovendo a formação do Hidrogel, os quais associados entre si formam um compósito, o TRG, que foi aplicado sobre uma lesão padrão no joelho da pata pélvica direita de ratos Wistar machos de seis meses de idade. Para a obtenção da lesão padrão, os animais foram divididos em três grupos de cincoanimais e cada grupo foi submetido a uma intervenção cirúrgica em seus joelhos direitos, utilizando três técnicas cirúrgicas diferentes, a saber: Grupo (I): Remoção cirúrgica dos meniscos medial e lateral mais perfuração do platô tibial seguido da aspiração da medula óssea através dessa perfuração por meio de seringa e agulha. Grupo (II): Remoção dos meniscos mais perfuração, sem aspiração, Grupo (III): Apenas a perfuração. Todos os animais foram autopsiados após 30 dias. Os joelhos dos quinze animais que constituíam os três grupos foram devidamente catalogados e enviados para a empresa Histotech, para a confecção das lâminas, tendo sido eleito, por análise histológica, o Grupo (I), por demonstrar menor reparo tecidual espontâneo. Em tese, o TRG teria as seguintes propriedades: Uma fonte de reparação tecidual (visco terapia) dada pelo HA e a capacidade amortecedora e carreadora de células-tronco do polímero PVA, que se hidrata, formando o hidrogel. O Ti, pela sua propriedade de osteointegração formaria um tampão sobre as áreas de matriz óssea exposta o que possibilitaria o afluxo de novos condrócitos, que também pode ocorrer pela ação das células-tronco. Livrar a superfície articular das áreas com exposição da matriz óssea é fundamental para o bloqueio das proteases que perpetuam a fisiopatologia da OA. Após tratamento estatístico dos diversos ensaios, utilizando-se os diversos biomateriais no tratamento da lesão, o TRG foi o biomaterial que apresentou o melhor resultado de força entre os grupos. No estudo histológico, foi evidenciada a presença de tecido cartilaginoso supra- lesional, o que só ocorreu nos animais dos grupos que receberam: apenas TRG, TRG associado com células-tronco e aquele que recebeu apenas MSCs. No entanto, mais estudos, com animais de maior porte e mais velhos, devem ser realizados para melhor analisar a segurança e o potencial terapêutico do compósito Trigel. / Osteoarthritis, or osteoarthritis (OA) is the third most debilitating disease in the world. In this study, we attempted to create an osteocartilaginous lesion in the knees of six months old male Wistar rats, aiming to constitute an animal model for the study of human OA and to use this model to evaluate the therapeutic potential of biomaterials, which are already well known for their biocompatibility properties in the clinical practice. The biomaterials were used in isolation or associated with each other and then evaluated for their biological safety and tissue repair capacity. Mesenchymal stem cells, obtained from human dental pulp from deciduous teeth (MSC) were evaluated alone and in association with the biomaterial formed by: Titanium + Poly Vinyl Alcohol + Ac. Hyaluronic, here called TRIGEL (TRG). Due to its visco-elastic properties, the Ti powder, due to its unique biological properties of ostointegration and the polymer PVA, with its hydrophylic properties, forming a hydrogel, were associated to form the composite named TRIGEL, (TRG), which was applied to a standard knee injury of the right hind leg of male Wistar rats. In order to elect the standard lesion, the animals were divided into three groups with five animals each and each group underwent a surgical intervention in their right knees, with three different surgical techniques being applied, namely: Group (1): Surgical removal ofmedial and lateral meniscus plus perforation of the tibial plateau, followed by aspiration of the bone marrow through this perforation using syringe and needle. Group (2): Removal of the meniscus plus perforation, without aspiration, Group (3): Drilling only. All groups were autopsied 30 days after the procedure and all groups were autopsied at 30 days post-procedure. The knees of the 15 animals that constituted the three groups were analyzed histologically and Group (1) (meniscus removed, perforated and aspirated), was elected as the standard lesion since it demonstrated less spontaneous tissue repair. TRG has the following properties: HA is used as a source of tissue repair (visco therapy) and hydration of the polymer; PVA, forms a hydrogel\", with damping action and as a stem cells carrier, whereas Ti was used due to its ósseo-integration, which would allow coating of the exposed bone matrix and this intra-osseous osteo-integration response would form an intercalating buffer. The healthy cartilage surfaces around this structural buffer would allow the reception of new chondrocytes or the action of the cells on TRG properties. Freeing the articular surface of the areas with bone matrix exposure is critical for blocking the proteases that perpetuate the pathophysiology of OA. In the various biomaterial tests in the treatment of the standard lesions, TRG was statistically shown to be the one that better mimicked the non-injured group. The histological study demonstrated the presence of a supra-lesional cartilagenous tissue, which only occurred in the groups which received: only TRG, mesenchymal stem cells associated with TRG and that which received only MSCs. However, further studies with larger and older animals should be pursued to better assess the safety and therapeutic potential of the Trigel composite.

No description available.

Denna uppsats är gjord på uppdrag av Tarbit Shipping som år 2011 konverterade sin tankbåt M/T Bit Viking från konventionell drift på tjockolja till LNG (Liquefied Natural Gas).Uppdraget som gavs var att upprätta en tränings manual till fartyget då det är ett krav från IMO (International Maritime Organization). Manualen skrevs i 3 st huvuddelar Kategori A, B och C. Kategori A är till för att manskap ombord ska få en kännedom om gasen och säkerhet runt den, Kategori B är skriven till däcksbefäl där det krävs en större kännedom om gasen och Kategori C är till för maskinbefäl. Manualen finns nu ombord på fartyget och på rederi kontoret för utbildning av nypåmönstrad personal och fortlöpande utbildning av ordinarie personal. Manualen är ett resultat på tolkning av IMO´s IGF kod (ANNEX11. RESOLUTION MSC.285(86)) där det står riktlinjer för säkerheten ombord på fartyg med maskiner som drivs på naturgas. / This paper has been produced as a result of an assignment set by Tarbit Shipping which 2011converted one of their product tanker ships from M/T Bit Viking its original heavy fuel oil toLNG (Liquefied Natural Gas). The assignment was to establish a training manual to the shipaccording to IMO´s (International Maritime Organization) IGF code. The manual is written inthree main parts Category A, Category B and Category C. Category A is directed at ratingsand cadets and focuses on gas and safety procedures, Category B is directed at deck officersand focuses on gas, whilst Category C is directed at engine officers and, similar to Category Baims at increasing knowledge levels for engineers. The manual is now located onboard theship and at the company’s office for education of new personnel and for continued educationfor personnel onboard. The manual is a result on an interpretation of IMO´s IGF code(ANNEX11. RESOLUTION MSC.285(86)), in which guidelines are laid out for vesselsfueled by natural gas.

Background: Multipotent mesenchymal stromal cells (MSC) can be recovered from a variety of tissues in the body. Yet, their functional properties were shown to vary depending on tissue origin. While MSC have emerged as a favoured cell type for tendon regenerative therapies, very little is known about the influence of the MSC source on their properties relevant to tendon regeneration. The aim of this study was to assess and compare the expression of tendon extracellular matrix proteins and tendon differentiation markers in MSC derived from different sources as well as in native tendon tissue. MSC isolated from equine bone marrow, adipose tissue, umbilical cord tissue, umbilical cord blood and tendon tissue were characterized and then subjected to mRNA analysis by real-time polymerase chain reaction. Results: MSC derived from adipose tissue displayed the highest expression of collagen 1A2, collagen 3A1 and decorin compared to MSC from all other sources and native tendon tissue (p < 0.01). Tenascin-C and scleraxis expressions were highest in MSC derived from cord blood compared to MSC derived from other sources, though both tenascin-C and scleraxis were expressed at significantly lower levels in all MSC compared to native tendon tissue (p < 0.01). Conclusions: These findings demonstrate that the MSC source impacts the cell properties relevant to tendon regeneration. Adipose derived MSC might be superior regarding their potential to positively influence tendon matrix reorganization.

BACKGROUND: In order to better understand the multifactorial nature of osteoporosis, animal models are utilized and compared to healthy controls. Female sheep are well established as a model for osteoporosis induced by ovariectomy, calcium and vitamin D low diet, application of steroids, or a combination of these treatments. Transcriptional studies can be performed by applying quantitative real time PCR (RT-qPCR). RT-qPCR estimates mRNA-levels of target genes in relation to reference genes. A chosen set of reference genes should not show variation under experimental conditions. Currently, no standard reference genes are accepted for all tissue types and experimental conditions. Studies examining reference genes for sheep are rare and only one study described stable reference in mandibular bone. However, this type of bone differs from trabecular bone where most osteoporotic fractures occur. The present study aimed at identifying a set of reference genes for relative quantification of transcriptional activity of ovine spine bone and ovine in vitro differentiated mesenchymal stromal cells (MSC) for reliable comparability. METHODS: Twelve candidate reference genes belonging to different functional classes were selected and their expression was measured from cultured ovMSCs (n = 18) and ovine bone samples (n = 16), respectively. RefFinder was used to rank the candidate genes. RESULTS: We identified B2M, GAPDH, RPL19 and YWHAZ as the best combination of reference genes for normalization of RT-qPCR results for transcriptional analyses of these ovine samples. CONCLUSION: This study demonstrates the importance of applying a set of reference genes for RT-qPCR analysis in sheep. Based on our data we recommend using four identified reference genes for relative quantification of gene expression studies in ovine bone or for in vitro experiments with osteogenically differentiated ovine MSCs.

BACKGROUND: In order to better understand the multifactorial nature of osteoporosis, animal models are utilized and compared to healthy controls. Female sheep are well established as a model for osteoporosis induced by ovariectomy, calcium and vitamin D low diet, application of steroids, or a combination of these treatments. Transcriptional studies can be performed by applying quantitative real time PCR (RT-qPCR). RT-qPCR estimates mRNA-levels of target genes in relation to reference genes. A chosen set of reference genes should not show variation under experimental conditions. Currently, no standard reference genes are accepted for all tissue types and experimental conditions. Studies examining reference genes for sheep are rare and only one study described stable reference in mandibular bone. However, this type of bone differs from trabecular bone where most osteoporotic fractures occur. The present study aimed at identifying a set of reference genes for relative quantification of transcriptional activity of ovine spine bone and ovine in vitro differentiated mesenchymal stromal cells (MSC) for reliable comparability. METHODS: Twelve candidate reference genes belonging to different functional classes were selected and their expression was measured from cultured ovMSCs (n = 18) and ovine bone samples (n = 16), respectively. RefFinder was used to rank the candidate genes. RESULTS: We identified B2M, GAPDH, RPL19 and YWHAZ as the best combination of reference genes for normalization of RT-qPCR results for transcriptional analyses of these ovine samples. CONCLUSION: This study demonstrates the importance of applying a set of reference genes for RT-qPCR analysis in sheep. Based on our data we recommend using four identified reference genes for relative quantification of gene expression studies in ovine bone or for in vitro experiments with osteogenically differentiated ovine MSCs.

This master thesis focuses on modelling and simulation of impact tests of composite panels. Simulations and analysis were made by using Finite Element Method in software MSC Patran and Dytran. The first part of the thesis deals with describing the properties of composite panels during impact testing and other cases of impacts on composite structures. Next part deals with the used models and results from Dytran. These results are compared with experimental data from real low-velocity impact tests. Part of the thesis is devoted to impact on panels with the stacking sequences which is supposed to be used for design of air duct for airplane Aero L-39NG.