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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Microenvironnement et angiogénèse : implications dans la stratégie onco-chirurgicale des métastases hépatiques synchrones des cancers colorectaux / Microenvironment and angiogenesis : impact on onco-surgical management of synchronous colorectal liver metastases.

Lim, Chetana 12 June 2017 (has links)
Lors du diagnostic de cancer colorectal, près d’un quart des patients ont des métastases hépatiques dites synchrones. Lorsque la tumeur primitive est asymptomatique, la stratégie chirurgicale (chirurgie première de la tumeur primitive versus chirurgie première des métastases hépatiques) reste débattue. Les recommandations actuelles ne reposent que sur des accords d’experts qui elles-mêmes sont basées sur des études cliniques rétrospectives. L’étude du microenvironnement tumoral a pris ces dernières années une place majeure dans la recherche sur le cancer. Elle a permis de changer de paradigme avec une nouvelle conception du processus métastatique : une tumeur primitive peut agir sur le microenvironnement du futur site métastatique pour créer une "niche pré-métastatique". Cette niche pré-métastatique permettrait secondairement la croissance des cellules tumorales via une angiogénèse tumorale et la formation de métastases. Par une triple approche à la fois fondamentale, translationnelle et clinique, nous avons obtenu des données qui suggèrent qu’une chirurgie première de la tumeur colique ou rectale permet de moduler l’angiogénèse au sein du microenvironnement hépatique. Cette stratégie chirurgicale permettrait également d’améliorer le pronostic oncologique des malades et l’efficacité des anti-angiogéniques. / At the time of the diagnosis of colorectal cancer, nearly 25% of patients have synchronous liver metastases. When this tumor is asymptomatic, the question of surgical strategy (primary tumor first versus liver-first strategy) remains debated. Current recommendations are based on agreements of experts which are by themselves based on retrospective clinical studies. The study of the tumor microenvironment has taken in recent years a major place in the field of cancer research. It leads to new paradigm with a new conception of the metastatic process. It may be possible that the microenvironment of the metastatic sites can be modulated by the primary tumor to promote the formation of the pre-“metastatic niche”. This leads to promote the growth of cancer cells and increase the metastatic potential of primary tumor. By a multidisciplinary research including fundamental, translational and clinical approaches, we have shown that primary tumor first strategy could modulate tumor angiogenesis and liver metastatic process. It is associated with improved survival of patients and efficacy of the anti-angiogenic therapy.
72

Endothelial Colony Forming Cells (ECFCs): Identification, Specification and Modulation in Cardiovascular Diseases

Huang, Lan 02 February 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / A hierarchy of endothelial colony forming cells (ECFCs) with different levels of proliferative potential has been identified in human circulating blood and blood vessels. High proliferative potential ECFCs (HPP-ECFCs) display properties (robust proliferative potential in vitro and vessel-forming ability in vivo) consistent with stem/progenitor cells for the endothelial lineage. Corneal endothelial cells (CECs) are different from circulating and resident vascular endothelial cells (ECs). Whereas systemic vascular endothelium slowly proliferates throughout life, CECs fail to proliferate in situ and merely expand in size to accommodate areas of CEC loss due to injury or senescence. However, we have identified an entire hierarchy of ECFC resident in bovine CECs. Thus, this study provides a new conceptual framework for defining corneal endothelial progenitor cell potential. The identification of persistent corneal HPP-ECFCs in adult subjects might contribute to regenerative medicine in corneal transplantation. While human cord blood derived ECFCs are able to form vessels in vivo, it is unknown whether they are committed to an arterial or venous fate. We have demonstrated that human cord blood derived ECFCs heterogeneously express gene transcripts normally restricted to arterial or venous endothelium. They can be induced to display an arterial gene expression pattern after vascular endothelial growth factor 165 (VEGF165) or Notch ligand Dll1 (Delta1ext-IgG) stimulation in vitro. However, the in vitro Dll1 primed ECFCs fail to display significant skewing toward arterial EC phenotype and function in vivo upon implantation, suggesting that in vitro priming is not sufficient for in vivo specification. Future studies will determine whether ECFCs are amenable to specification in vivo by altering the properties of the implantation microenvironment. There is emerging evidence suggesting that the concentration of circulating ECFCs is closely related to the adverse progression of cardiovascular disorders. In a pig model of acute myocardial ischemia (AMI), we have demonstrated that AMI rapidly mobilizes ECFCs into the circulation, with a significant shift toward HPP-ECFCs. The exact role of the mobilized HPP-ECFCs in homing and participation in repair of the ischemic tissue remains unknown. In summary, these studies contribute to an improved understanding of ECFCs and suggest several possible therapeutic applications of ECFCs.
73

Stratégies cellulaires et environnementales pour le développement d’un substitut osseux prévascularisé / Cellular and environmental strategies for the development of a prevascularized bone subsitute

Willemin, Anne-Sophie 21 September 2018 (has links)
En cas de pertes de substances osseuses de grande étendue, la capacité naturelle de réparation du tissu osseux n’est pas suffisante et nécessite d’être assistée. La greffe d’os autologue constitue actuellement la référence. Cependant, cette thérapeutique présente tout de même des inconvénients qui ont entrainé le développement de substituts osseux. Mais, aucun matériau à ce jour ne peut remplacer totalement l’os autologue, en raison notamment de la difficulté à recréer un système vasculaire fonctionnel au niveau du site lésé. Depuis quelques années, les espoirs se tournent vers la création d’un substitut osseux prévascularisé afin de pallier la principale limite des alternatives actuelles : l’établissement d’un réseau vasculaire au sein de ce biomatériau. Notre projet vise à évaluer l’effet stimulateur d’un composé naturel, les principes actifs de la nacre solubles dans l’éthanol (appelé Ethanol Soluble Matrix, ESM), à la fois sur les capacités angiogéniques de cellules de la lignée endothéliale et sur la différenciation ostéogénique de cellules souches mésenchymateuses (CSM) avec comme objectif le développement d’un substitut osseux prévascularisé. Dans un premier temps, nous avons montré que l’ESM stimulait les capacités angiogéniques des cellules de la lignée endothéliale : cellules endothéliales matures (HUVECs, cellules endothéliales issues de la veine ombilicale humaine) et cellules progénitrices endothéliales (CPEs) issues de sang de cordon. L'ESM, utilisé à la concentration de 200µg/mL, a permis de dépasser les résultats obtenus (expression génique et test fonctionnel) avec le milieu de culture de référence des CPEs : l’EGM-2 (Endothelial Growth Medium). Nous avons ensuite mis en évidence que l’ESM exerçait un effet stimulateur également sur les CSMs en augmentant l’expression de marqueurs spécifiques des chondrocytes et des chondrocytes hypertrophiques, suggérant une orientation de ces cellules vers une ossification endochondrale. En parallèle de ces travaux, nous avons étudié l’effet paracrine des CSMs sur les cellules de la lignée endothéliale, HUVECs et CPEs. Les vésicules extracellulaires de taille nanométrique (nEVs) ont montré leur capacité à induire une stimulation in vitro de la formation de réseaux vasculaires et de l’expression de gènes endothéliaux. Ces résultats encourageants soulignent la faisabilité de l’utilisation de l’ESM en tant que stimulus à la fois de l’angiogenèse des CPEs et de l’ostéogenèse des CSMs. Ce stimulus pourrait être associé aux nEVs issues de CSMs et aux CPEs au sein d’une matrice tridimensionnelle pour développer un substitut osseux prévascularisé / In case of critical-sized defects, the bone tissue ability of natural healing is not sufficient and needs to be assisted. The autologous bone graft is currently the gold standard. However, this solution has drawbacks that have led to the development of bone substitutes. Nowadays, no substitute is able to supply autogenous bone, due to the difficulties to mimic the vascular system. In recent years, the hopes are focusing on the creation of a prevascularized bone substitute to overcome the main limitation of current alternatives: the creation of a functional vascular network inside the substitute. Our project aims to evaluate the stimulating effect of a natural compound, the nacre extracts called Ethanol Soluble Matrix (ESM), both on the angiogenic abilities of endothelial cell lineage and on the osteogenic differentiation of mesenchymal stem cells (MSCs) to develop a pre-vascularized bone substitute. First, we showed that ESM stimulates the angiogenic potential of two types of endothelial cells: mature endothelial cells (HUVECs, human umbilical vein endothelial cells) and endothelial progenitor cells (EPCs) from cord blood. The ESM, used at the concentration of 200µg/mL, exceeded results obtained with the reference culture medium of EPCs: the EGM-2 (Endothelial Growth Medium). Then, we demonstrated that ESM also exerted a stimulating effect on MSC by increasing the expression of chondrocyte and hypertrophic chondrocyte specific markers, suggesting an orientation of these cells towards endochondral ossification. In line with this work, we studied the paracrine effect of MSCs on endothelial cell lineage, HUVECs and EPCs. Nanoscale extracellular vesicles (nEVs) have been shown to induce an in vitro stimulation of the vascular network formation and of the endothelial gene expression. These encouraging results highlight the feasibility of using ESM as a stimulus for both angiogenesis of EPCs and osteogenesis of MSCs. This stimulus could be associated with MSC-derived nEVs and EPCs within a three-dimensional matrix to develop a pre-vascularized bone substitute
74

Protektion humaner endothelialer Vorläuferzellen durch die Koapplikation mit Mesenchymalen Stamm-/Vorläuferzellen

Souidi, Naima 14 December 2017 (has links)
Endothelzell-basierte Therapien vermitteln regenerative Effekte hinsichtlich der Revaskularisierung von ischämischen Geweben. Doch ist die Verfügbarkeit von autologen Endothelzellen aufgrund einer krankheitsbedingt reduzierten Frequenz im peripheren Blut oder einer verminderten Integrität der endogenen Endothelzell-Populationen eingeschränkt. Hingegen ist es möglich, allogene endotheliale Vorläuferzellen aus der Nabelschnur in zelltherapeutisch relevanten Mengen zu isolieren. In der vorliegenden Arbeit wurden zunächst die Eigenschaften allogener humaner Nabelschnur (NS)-abgeleiteter sog. Endothelial Colony-Forming Cells (ECFCs) mit denen von venösen NS-abgeleiteten Endothelzellen verglichen. Aufgrund der nachgewiesenen Immunogenität von allogenen ECFCs wurde eine weiterführende Strategie zur Reduktion dieser immunogenen Eigenschaften durch die Koapplikation mit Mesenchymalen Vorläuferzellen (MSCs) verfolgt. Humane ECFCs wurden mit MSCs desselben Spenders kombiniert und in funktionellen in vitro- und in vivo-Assays untersucht. Dadurch konnte nachgewiesen werden, dass IFNγ-stimulierte ECFC/MSC-Kokulturen eine reduzierte Expression von HLA-Molekülen zeigen. Entsprechend induzierten spezifische CD8+ T-Zellen eine reduzierte Lyse der kokultivierten ECFCs und MSCs. Die Kokultur von ECFCs und MSCs mit allogenen Immunzellen führte zu einer nahezu vollständigen Inhibition der T-Zell-Proliferation. Um die reduzierte Immunogenität von ECFC und MSC in vivo zu verifizieren, wurden die Zellen in immundefiziente Mäuse injiziert, welche nachfolgend mit humanen PBMCs rekonstituiert wurden. So konnte nachgewiesen werden, dass die Koapplikation von ECFCs und MSCs nicht nur die Entstehung von stabilen Gefäßnetzwerken begünstigt, sondern zudem in den Transplantaten zu einer verringerten Immunzell-Infiltration führte. Die Koapplikation von ECFCs mit MSCs könnte daher eine klinische Nutzung dieser allogenen Quelle für die therapeutische Unterstützung der Vaskularisierung ermöglichen. / Endothelial cell-based therapies promote tissue regeneration and vascularization after ischemic damage. The availability of autologous endothelial progenitor cells is restricted in diseased patients, however therapeutically relevant numbers of allogeneic Endothelial Progenitor Cells can be isolated from an umbilical cord (UC). In the present study, the immunogenic properties of these Endothelial Colony Forming Cells (ECFCs) were first compared to human umbilical vein endothelial cells (HUVECs). Both cytokine-treated endothelial cells induced CD4+ and CD8+ T cell proliferation after coculture with allogeneic immune cells. So far, the potential interactions between ECFCs and Mesenchymal Stem/Progenitor Cells (MSCs) concerning their immunological features is poorly understood, but we hypothesize that MSCs might improve the immune compatibility and vessel building characteristics of ECFCs. Therefore, human UC-derived ECFC and MSC cocultures from the same donor were analyzed using various functional in vitro and in vivo assays. Stimulation of these cocultures with IFNγ caused strongly reduced expression levels of HLA-molecules compared to ECFC monocultures. The decreased molecular density on the cocultured ECFCs resulted in reduced cytotoxic CD8+ T cell-mediated lysis. Further, during IFNγ stimulation, the combination of ECFCs with MSCs prevented initiation of allogeneic T cell proliferation. To verify this concept in vivo, ECFCs and MSCs were co-transplanted in a humanized allograft mouse model in immunodeficient mice in order to effectively induce stable microvessels. These experiments demonstrate that when MSCs are co-applied with ECFCs, they not only support the formation of stable blood vessels, but also lead to fewer HLA-DR+ human vascular structures and fewer infiltrating human leukocytes. The data presented indicate that crosstalk between UC-derived ECFCs and MSCs might lower the risk of allogeneic ECFC rejection.
75

Hipogonadismo associado à  obesidade: efeitos do tratamento com citrato de clomifeno / Obesity related hypogonadism: clomiphene citrate treatment effects

Soares, Andressa Heimbecher 26 March 2018 (has links)
INTRODUÇÃO: A obesidade é uma das causas de hipogonadismo (HG) secundário no homem. A terapia de reposição padrão de testosterona (TRT) é associada à melhora dos parâmetros metabólicos, mas pode levar à infertilidade. Apenas recentemente indicou-se que não há novas evidências nível 1 para apoiar uma conexão definitiva entre TRT e eventos cardiovasculares (CV). OBJETIVO: Avaliar os efeitos do Citrato de Clomifeno (CC) em homens jovens com hipogonadismo associado à obesidade diagnosticado por testosterona total (TT) <= 300 ng/dL em duas ocasiões, sintomas positivos no questionário ADAM, hormônio Luteinizante (LH) baixo ou inadequadamente normal (VR: 1,7 - 8,6 UI/L). MÉTODOS: Estudo randomizado, duplo cego, controlado por placebo (PLB), longitudinal em centro único. Setenta e oito pacientes com idade entre 36,5±7,8 anos, índice de massa corporal (IMC) 46,2±8,5 kg/m2 foram randomizados (1:1) para receber CC 50 mg ou PLB durante 12 semanas. Os pacientes foram avaliados através de: 1) Parâmetros clínicos: Questionário ADAM, número de intercursos sexuais, queixa de insatisfação com a vida sexual; 2) Parâmetros hormonais: dosagem sérica de TT, testosterona livre, Estradiol (E2), LH, hormônio folículo estimulante (FSH), SHBG, relação TT:E2; 3) Parâmetros de composição corporal: IMC, circunferência abdominal (CA) e análise de bioimpedanciometria; 4) Parâmetros metabólicos: pressão arterial sistólica e diastólica, glicemia em jejum (GJ), hemoglobina glicada (HbA1c), índice HOMA-IR, colesterol total e frações, triglicérides; 5) Parâmetros de resposta CV: dilatação fluxo mediada artéria braquial (FMDAB), níveis circulantes de sICAM-1, sVCAM-1, Selectina-sE e quantificação de células endoteliais progenitoras (CEPs) por citometria de fluxo; 6) Efeitos adversos: hematócrito, antígeno prostático específico sérico (PSA), questionário internacional de sintomas prostáticos (I-PSS), dosagem sérica de alanina aminotransferase (ALT), aspartato aminotransferase (AST), e efeitos adversos autorreferidos. RESULTADOS: Na randomização os dois grupos foram semelhantes em relação à idade (CC: 35,5±7,8 anos, PLB: 35,6±7,8; p= 0,951), IMC (CC: 45,5±11,3 kg/m2; PLB: 47,2±9,6; p= 0,470), CA (CC: 137,5±17,9 cm; PLB: 140,2±19,6; p= 0,526) e testosterona total (CC: 225,8±70,0 ng/dL; PLB: 216,0±72,1; p= 0,543). Não houve diferenças nos parâmetros de resposta clínica, exceto com relação à queixa de perda de vigor nas ereções (p < 0,001). Observou-se elevação significativa (p= < 0,001) de TT, Testosterona livre, E2, LH, FSH e SHBG no grupo CC em comparação com PLB. Houve um aumento significativo (p < 0,001) na massa magra e na massa muscular; e também na massa livre de gordura (p= 0,004). O CC reduziu HDL em comparação com PLB (p < 0,001) e não mostrou efeito em outros parâmetros metabólicos. Não houve significância estatística nos parâmetros CV, indicando efeito nulo do tratamento. CC reduziu ALT (p < 0,001) e aumentou o PSA (p= 0,023) dentro dos limites da normalidade. CONCLUSÕES: CC foi efetivo para melhorar os parâmetros de resposta hormonal e afetou positivamente um parâmetro de resposta clínica (perda de vigor nas ereções). Apesar das alterações na composição corporal, não se observou melhora do perfil metabólico. No entanto, o CC não ocasionou resposta adversa nos parâmetros CV. O tratamento CC para HG parece ser uma alternativa efetiva em jovens obesos que desejam preservar sua fertilidade, mas ensaios clínicos de seguimento em longo prazo e com maior número de participantes são necessários para melhor análise do perfil metabólico e de sintomas, além de impactos CV / INTRODUCTION: Obesity can cause secondary hypogonadism in man. The standard testosterone replacement therapy (TRT) improves metabolic parameters but can lead to infertility. Only recently TRT was not clearly associated with adverse cardiovascular (CV) events, but its impacts on endothelial function are still controversial. AIM: To evaluate the effects of Clomiphene Citrate (CC) in out clinic young man with obesity related hypogonadism: total testosterone (TT) <= 300 ng/dL on two occasions, positive symptoms in ADAM questionnaire, Luteinizing Hormone (LH) low or inappropriate normal (RV: 1.7-8.6 IU/liter). METHODS: This is a randomized, double blind, placebo-controlled, parallel group, single-center study. Seventy eight patients aged 36.5±7.8 years, Body mass index (BMI) 46.2±8.5 kg/m2 were randomized (1:1) to receive CC 50 mg or Placebo (PLB) during 12 weeks. MAIN OUTCOME MEASURES: 1) Clinical symptomology: ADAM Questionnaire, number of sexual intercourses and satisfaction with sexual life; 2) Hormonal monitoring: serum TT, Free testosterone, Estradiol (E2), LH and Follicle-stimulating hormone (FSH), SHBG, TT/E2 ratio; 3) Body composition and anthropometric measurements: BMI, waist circumference (WC) and Bioelectric Impedance analysis parameters; 4) Metabolic response parameters: systolic and diastolic blood pressure, fasting blood glucose (FBG), glycated hemoglobin (HbA1c), serum cholesterol and fractions, triglycerides; 5) CV assessment by endothelial function parameters: Flowmediated dilatation of the brachial artery (FMDAB), circulating levels of sICAM-1, sVCAM-1, E-selectin and flow cytometry endothelial progenitor cells (EPCs); 6) Adverse outcomes: Hematocrit, serum Prostate-Specific Antigen (PSA), International Prostate Symptom Score (I-PSS), Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) and Selfreported Adverse Effects. RESULTS: Two groups were similar with regard to age (CC: 35.5±7.8 years; PLB: 35.6±7.8; P=0.951), BMI (CC: 45.5±11.3 kg/m2; PLB: 47.2±9.6; P=0.470), WC (CC: 137.5±17.9 cm; PLB: 140.2±19.6; P=0.526) and total testosterone (CC: 225.8±70.0 ng/dL; PLB: 216.0±72.1; P=0.543) in baseline data. There was an improvement in one sexual complaint (weaker erections) (P < 0.001) and there were significant improvements (P < 0.001) in TT, Free Testosterone, E2, LH, FSH and SHBG in CC group (vs. PLB). There was a gain in lean mass (P < 0.001), free fat mass (P=0.004) and muscle mass (P < 0.001). CC reduced HDL compared to PLB (P < 0.001) and showed no effect in other metabolic parameters. No statistical significance was seen in CV parameters. CC reduced ALT (P < 0.001) and increased PSA (P=0.023). CONCLUSIONS: CC was effective in increase hormonal response parametersand improved one sexual complaint (weaker erections). Despite body composition changes, CC did not improved metabolic profile and lowered LDL cholesterol. CC showed no adverse response in CV parameters. CC treatment for HG appears to be an effective alternative in young obese men wishing to preserve their fertility but long-term follow-up trials to better analyze the metabolic profile and CV outcomes are needed
76

High-Density Lipoproteins (HDL) Functionality in Degenerative Cardiac Disease - Novel Cardioprotective Roles of HDL and Strategies to Target HDL Dysfunction

Gebhard, Catherine S. 04 1900 (has links)
No description available.
77

Hipogonadismo associado à  obesidade: efeitos do tratamento com citrato de clomifeno / Obesity related hypogonadism: clomiphene citrate treatment effects

Andressa Heimbecher Soares 26 March 2018 (has links)
INTRODUÇÃO: A obesidade é uma das causas de hipogonadismo (HG) secundário no homem. A terapia de reposição padrão de testosterona (TRT) é associada à melhora dos parâmetros metabólicos, mas pode levar à infertilidade. Apenas recentemente indicou-se que não há novas evidências nível 1 para apoiar uma conexão definitiva entre TRT e eventos cardiovasculares (CV). OBJETIVO: Avaliar os efeitos do Citrato de Clomifeno (CC) em homens jovens com hipogonadismo associado à obesidade diagnosticado por testosterona total (TT) <= 300 ng/dL em duas ocasiões, sintomas positivos no questionário ADAM, hormônio Luteinizante (LH) baixo ou inadequadamente normal (VR: 1,7 - 8,6 UI/L). MÉTODOS: Estudo randomizado, duplo cego, controlado por placebo (PLB), longitudinal em centro único. Setenta e oito pacientes com idade entre 36,5±7,8 anos, índice de massa corporal (IMC) 46,2±8,5 kg/m2 foram randomizados (1:1) para receber CC 50 mg ou PLB durante 12 semanas. Os pacientes foram avaliados através de: 1) Parâmetros clínicos: Questionário ADAM, número de intercursos sexuais, queixa de insatisfação com a vida sexual; 2) Parâmetros hormonais: dosagem sérica de TT, testosterona livre, Estradiol (E2), LH, hormônio folículo estimulante (FSH), SHBG, relação TT:E2; 3) Parâmetros de composição corporal: IMC, circunferência abdominal (CA) e análise de bioimpedanciometria; 4) Parâmetros metabólicos: pressão arterial sistólica e diastólica, glicemia em jejum (GJ), hemoglobina glicada (HbA1c), índice HOMA-IR, colesterol total e frações, triglicérides; 5) Parâmetros de resposta CV: dilatação fluxo mediada artéria braquial (FMDAB), níveis circulantes de sICAM-1, sVCAM-1, Selectina-sE e quantificação de células endoteliais progenitoras (CEPs) por citometria de fluxo; 6) Efeitos adversos: hematócrito, antígeno prostático específico sérico (PSA), questionário internacional de sintomas prostáticos (I-PSS), dosagem sérica de alanina aminotransferase (ALT), aspartato aminotransferase (AST), e efeitos adversos autorreferidos. RESULTADOS: Na randomização os dois grupos foram semelhantes em relação à idade (CC: 35,5±7,8 anos, PLB: 35,6±7,8; p= 0,951), IMC (CC: 45,5±11,3 kg/m2; PLB: 47,2±9,6; p= 0,470), CA (CC: 137,5±17,9 cm; PLB: 140,2±19,6; p= 0,526) e testosterona total (CC: 225,8±70,0 ng/dL; PLB: 216,0±72,1; p= 0,543). Não houve diferenças nos parâmetros de resposta clínica, exceto com relação à queixa de perda de vigor nas ereções (p < 0,001). Observou-se elevação significativa (p= < 0,001) de TT, Testosterona livre, E2, LH, FSH e SHBG no grupo CC em comparação com PLB. Houve um aumento significativo (p < 0,001) na massa magra e na massa muscular; e também na massa livre de gordura (p= 0,004). O CC reduziu HDL em comparação com PLB (p < 0,001) e não mostrou efeito em outros parâmetros metabólicos. Não houve significância estatística nos parâmetros CV, indicando efeito nulo do tratamento. CC reduziu ALT (p < 0,001) e aumentou o PSA (p= 0,023) dentro dos limites da normalidade. CONCLUSÕES: CC foi efetivo para melhorar os parâmetros de resposta hormonal e afetou positivamente um parâmetro de resposta clínica (perda de vigor nas ereções). Apesar das alterações na composição corporal, não se observou melhora do perfil metabólico. No entanto, o CC não ocasionou resposta adversa nos parâmetros CV. O tratamento CC para HG parece ser uma alternativa efetiva em jovens obesos que desejam preservar sua fertilidade, mas ensaios clínicos de seguimento em longo prazo e com maior número de participantes são necessários para melhor análise do perfil metabólico e de sintomas, além de impactos CV / INTRODUCTION: Obesity can cause secondary hypogonadism in man. The standard testosterone replacement therapy (TRT) improves metabolic parameters but can lead to infertility. Only recently TRT was not clearly associated with adverse cardiovascular (CV) events, but its impacts on endothelial function are still controversial. AIM: To evaluate the effects of Clomiphene Citrate (CC) in out clinic young man with obesity related hypogonadism: total testosterone (TT) <= 300 ng/dL on two occasions, positive symptoms in ADAM questionnaire, Luteinizing Hormone (LH) low or inappropriate normal (RV: 1.7-8.6 IU/liter). METHODS: This is a randomized, double blind, placebo-controlled, parallel group, single-center study. Seventy eight patients aged 36.5±7.8 years, Body mass index (BMI) 46.2±8.5 kg/m2 were randomized (1:1) to receive CC 50 mg or Placebo (PLB) during 12 weeks. MAIN OUTCOME MEASURES: 1) Clinical symptomology: ADAM Questionnaire, number of sexual intercourses and satisfaction with sexual life; 2) Hormonal monitoring: serum TT, Free testosterone, Estradiol (E2), LH and Follicle-stimulating hormone (FSH), SHBG, TT/E2 ratio; 3) Body composition and anthropometric measurements: BMI, waist circumference (WC) and Bioelectric Impedance analysis parameters; 4) Metabolic response parameters: systolic and diastolic blood pressure, fasting blood glucose (FBG), glycated hemoglobin (HbA1c), serum cholesterol and fractions, triglycerides; 5) CV assessment by endothelial function parameters: Flowmediated dilatation of the brachial artery (FMDAB), circulating levels of sICAM-1, sVCAM-1, E-selectin and flow cytometry endothelial progenitor cells (EPCs); 6) Adverse outcomes: Hematocrit, serum Prostate-Specific Antigen (PSA), International Prostate Symptom Score (I-PSS), Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) and Selfreported Adverse Effects. RESULTS: Two groups were similar with regard to age (CC: 35.5±7.8 years; PLB: 35.6±7.8; P=0.951), BMI (CC: 45.5±11.3 kg/m2; PLB: 47.2±9.6; P=0.470), WC (CC: 137.5±17.9 cm; PLB: 140.2±19.6; P=0.526) and total testosterone (CC: 225.8±70.0 ng/dL; PLB: 216.0±72.1; P=0.543) in baseline data. There was an improvement in one sexual complaint (weaker erections) (P < 0.001) and there were significant improvements (P < 0.001) in TT, Free Testosterone, E2, LH, FSH and SHBG in CC group (vs. PLB). There was a gain in lean mass (P < 0.001), free fat mass (P=0.004) and muscle mass (P < 0.001). CC reduced HDL compared to PLB (P < 0.001) and showed no effect in other metabolic parameters. No statistical significance was seen in CV parameters. CC reduced ALT (P < 0.001) and increased PSA (P=0.023). CONCLUSIONS: CC was effective in increase hormonal response parametersand improved one sexual complaint (weaker erections). Despite body composition changes, CC did not improved metabolic profile and lowered LDL cholesterol. CC showed no adverse response in CV parameters. CC treatment for HG appears to be an effective alternative in young obese men wishing to preserve their fertility but long-term follow-up trials to better analyze the metabolic profile and CV outcomes are needed
78

Effets d'un polysaccharide sulfaté, le fucoïdane, sur la réparation osseuse induite par les cellules souches mésenchymateuses / Effects of a sulfated polysaccharide, the fucoidan, on bone repair by mesenchymal stem cells

Pereira, Jessica 12 July 2013 (has links)
Dans le cas de larges pertes de substance osseuse, l’ingénierie tissulaire représente une alternative intéressante aux greffes. Cette technique consiste à associer des cellules à des biomatériaux dans le but de réparer le tissu. L'objectif de ce travail est l'étude de l'amélioration du potentiel ostéogénique des cellules souches mésenchymateuses issues du tissue adipeux humain (ASC), afin d’augmenter la formation de matrice osseuse en territoire ischémique. Nous avons montré que le fucoïdane, un polysaccharide d’origine marine, était capable d’améliorer la différenciation ostéogénique des ASC in vitro. Cependant, la combinaison de ces cellules avec des biomatériaux (granules de biphosphate de calcium) ne suffit pas à permettre une formation osseuse dans un modèle de pousse osseuse en site ectopique chez la souris. Afin d’augmenter l’angiogenèse, essentielle dans la réparation osseuse, nous avons associé les ASC à des cellules progénitrices endothéliales (appelées ECFC), dans ce modèle. Cette association ne permet d’améliorer que faiblement la formation osseuse. Nos études in vitro d'association de CPE et d'ASC ont montré que ces cellules en coculture étaient capables de synthétiser un grand nombre de cytokines impliquées dans les différenciations ostéogénique et angiogénique, telles que le transforming growth factor (TGFß1), l’insulin like growth factor (IGF-1) ou encore le vascular endothelial growth factor (VEGF). Dans nos conditions de culture, le surnageant de l’association des ECFC avec des ASC induit, par rapport au surnageant des ASCs seules, une inhibition de la différenciation ostéogénique dont le mécanisme reste à identifier.L’ensemble de nos données démontre le potentiel du fucoïdane dans l’ingénierie tissulaire osseuse et que les ASC seules ne sont pas capables de former de matrice osseuse. / In the case of large bone defects, tissue engineering represents an attractive alternative to transplantation. Tissue engineering is a combination of cells with biomaterials in order to repair tissue. The aim of this work was the study of the improvement of the osteogenic potential of mesenchymal stromal/stem cells derived from human adipose tissue (ASC) in the order to increase the formation of bone matrix in the ischemic territory. We have shown that fucoidan, a marine polysaccharide, was able to improve the osteogenic differentiation of ASC in vitro. However, the combination of these cells with biomaterials (biphasic calcium phosphate particles) is not enough to have bone formation in an ectopic bone growth model in mice. To promote angiogenesis, a crucial step in bone repair, we associated ASC with endothelial progenitor cells (called ECFC), in our model. This association promotes only lightly the bone formation. Our in vitro coculture studies of ECFC with ASC showed that the cells in coculture were able to synthesize several cytokines involved in angiogenic and osteogenic differentiation, such as transforming growth factor (TGF-ß1), insulin like growth factor (IGF-1) or vascular endothelial growth factor (VEGF). However, ASC in coculture did not express the receptors of these cytokines. In our culture conditions, the supernatant of the association of ECFC + ASC induces, compare to ASC alone, an inhibition of osteogenic differentiation which mechanism has to be identified.Our data show the potential of fucoidan in bone tissue engineering and that ASC alone did not promote bone matrix formation.

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