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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.
131

Ánálise de alterações no gene receptor de andrógeno em homens com infertilidade idiopática / Analysis of changes in the androgen receptor gene in men with idiopathic infertility

MESQUITA, Wyara Elanne de Jesus Castro 31 March 2009 (has links)
Made available in DSpace on 2014-07-29T15:16:33Z (GMT). No. of bitstreams: 1 dissertacao wyara biologia.pdf: 1287742 bytes, checksum: 4b2f592f2b219248664d4916820cd874 (MD5) Previous issue date: 2009-03-31 / Male idiopathic infertility is related to defects in normal spermatogenesis, due to genetic causes. The spermatogenesis is a dependent process on high levels of male sex hormones, the androgens. The androgen, in turn, perform its function when associated with the androgen receptor (AR), protein encoded by AR gene. Mutation in AR gene lead to a synthesis of non functional AR, which results in the failure of the process of spermatogenesis and, consequently, causes male infertility. This work has as its main objective the verification of the occurrence of mutation in the AR gene in patients with male idiopathic infertility who come from the HC-UFG Human Reproduction Center. Samples were analyzed from 206 patients. The result was that 95 patients were found to be normal while 111 with an altered result for the spermogram. The samples were amplified for exons 1, 4, 6, 7 and 8 of the AR gene and the results subjected to statistical analysis, Mann Whitney, logistic regression, and chi tests. The existence of the relationship between defects of sperm and AR gene mutation was verified. The analysis of the relationship between the spermogram and the AR gene mutation in five evaluated exons was significant only for exons 1 and 7. Patients with numerical unsettled spermogram had a higher frequency of mutations in exon 7, teratozoospermics in exon 1 and exon 7 in astenozoospermics patients. Exons 4, 6 and 8 showed no meaningful statistical relationship in reference to the alteration of the spermogram. Among results related to social custom, alcohol proved to be significant for mutation in the AR gene. This study has reaffirmed the relationship between the presence of mutation in AR genes as probable causes of defects in spermatogenesis. Consequently, male idiopathic infertility depends not only on the genetic factor, but also on the association between this factor and the environment where man inhabits / A infertilidade masculina idiopática está relacionada a defeitos na espermatogênese normal, devido a causas genéticas. A espermatogênese é um processo dependente de altos níveis de hormônios sexuais masculinos, os andrógenos. E os andrógenos, por sua vez, exercem sua função quando associados ao receptor androgênico (RA), proteína codificada pelo gene RA. Mutações no gene RA levam a síntese do RA não funcional, o que acarreta em falhas no processo de espermatogênese e consequentemente causam infertilidade masculina. O trabalho teve como principal objetivo verificar a ocorrência ou não de mutação no gene RA em pacientes com infertilidade masculina idiopática do Centro de Reprodução Humana do HCUFG. Foram analisadas 206 amostras de pacientes, sendo 95 normais e 111 alterados para o espermograma. As amostras foram amplificadas para os exons 1, 4, 6, 7 e 8 do gene RA e os resultados submetidos às análises estatísticas, teste U, quiquadrado e regressão logística. Foi verificada a existência de relação entre alteração no espermograma e mutação no gene RA. A análise da relação entre espermograma e mutação no gene RA dos cinco exons avaliados foi significativa somente para os exons 1 e 7. Os pacientes com alteração numérica para o espermograma apresentaram uma freqüência maior de mutações no exon 7, os pacientes teratozoospérmicos no exon 1 e os astenozoospérmicos no exon 7. Os exons 4, 6 e 8 não apresentaram relação estatística significativa para alterações no espermograma. Dentre os resultados referentes aos hábitos sociais, o etilismo mostrou-se significativo para mutações no gene RA. A realização desse estudo vem reafirmar a relação entre presença de mutações no gene RA como prováveis causas de defeitos na espermatogênese e, consequentemente, infertilidade masculina idiopática, não dependendo exclusivamente do fator gênico, mas da associação entre este fator e o meio ambiente onde o homem está inserido
132

Avaliação da expressão imunoistoquímica de PTEN, AKT fosforilada e receptor de androgênio em carcinomas de mama HER-2 positivos / Immunohistochemical assesment of PTEN, phosphorilated AKT and androgen receptor expression in HER2-positive breast carcinomas

Francini de Mattos Lima Lin 17 December 2012 (has links)
INTRODUÇÃO: Os carcinomas HER-2 positivos representam cerca de 20- 30% de todos os tumores da mama e se caracterizam por curso clínico mais agressivo, com alta proliferação celular e resistência a apoptose, determinados por cascatas de sinalizações intracelulares, tais como a via PI3K/AKT. O trastuzumabe, um anticorpo monoclonal humanizado que se liga à molécula de HER-2, é o tratamento padrão destas pacientes. A resposta a monoterapia com trastuzumabe varia de 12-30% e a persistência da ativação da via PI3K/AKT é um dos mecanismos de resistência. A ativação do AKT começa com a fosforilação do PIP2 a PIP3 pela PI3K. A desfosforilação do PIP3 é mediada pela PTEN e sua deficiência é um dos fatores possivelmente implicados na resistência ao trastuzumabe. Além da resistência à terapêutica, os tumores HER-2 positivos são heterogêneos quanto ao seu comportamento biológico. A busca de diferentes padrões morfológicos e moleculares neste grupo de carcinomas pretende identificar subgrupos prognósticos e preditivos, permitindo a individualização terapêutica. OBJETIVOS: Estudar a expressão imunoistoquímica de duas moléculas da via de sinalização PI3K/AKT (PTEN e AKT fosforilada) e explorar a via de sinalização androgênica através da expressão do receptor de androgênio e dos perfis morfológico e molecular apócrinos. METODOLOGIA: O estudo foi retrospectivo com revisão dos preparados histológicos e construção de blocos de microarranjos com amostras dos tumores para estudo imunoistoquímico. Na revisão foram avaliados: tipo histológico, características morfológicas apócrinas, presença de componente in situ, graus histológico e nuclear, receptores de estrogênio e progesterona, e atividade proliferativa através da expressão imunoistoquímica do Ki-67. Os preparados histológicos foram submetidos à pesquisa de PTEN, AKT fosforilada e receptor de androgênio. Pacientes, familiares e médicos foram contatados para recuperação do seguimento e evolução. RESULTADOS: Foram estudadas 104 pacientes portadoras de carcinoma primário da mama. A expressão de PTEN esteve reduzida em 20/104 (19,2%) dos casos e foi mais freqüente nos tumores com AKT positivo (p= 0,06). O grupo de tumores sem perda de expressão de PTEN apresentou maior atividade proliferativa. A AKT foi positiva em 71/104 (68,3%) casos e se associou a maior grau de diferenciação e à expressão de receptor de androgênio. O receptor de androgênio foi positivo em 89/104 (85,6%) dos casos e esteve associado ao menor grau histológico (p=0,018), receptor de estrogênio (p=0,008) e menor atividade proliferativa (p=0,001). A ausência da expressão do receptor de estrogênio (perfil molecular apócrino) foi identificada em 41/104 casos (39,4%) e se associou a tumores com grau histológico mais alto. O perfil morfológico apócrino foi identificado em 71 (68,3%) dos casos e se associou a alto grau histológico e nuclear. O seguimento foi possível em 55 casos e observamos tendência a menor sobrevida livre de doença nos tumores AKTpositivos e RA-negativos. CONCLUSÕES: Nossos resultados comprovam a heterogeneidade dos carcinomas mamários HER-2 positivos e indicam diferenças em pelos menos duas vias de sinalização celulares como possíveis explicações para as mesmas: a via PI3K/AKT e a androgênica / BACKGROUND: HER-2 positive carcinomas represent about 20-30% of all breast tumors and are characterized by a more aggressive clinical course with high cell proliferation and apoptosis resistance, determined by cascades of intracellular signals, such as the PI3K/AKT pathway. Trastuzumab, a humanized monoclonal antibody that binds to HER-2 molecule, is the standard treatment for these patients. The response to monotherapy with trastuzumab ranges from 12-30% and the persistence of activation of the PI3K/AKT pathway is one of mechanisms of resistance. Activation of AKT begins with the phosphorylation of PIP2 to PIP3 by PI3K. The dephosphorylation of PIP3 is mediated by PTEN and its deficiency is one of the factors possibly involved in resistance to trastuzumab. In addition to resistance to therapy, HER-2 positive tumors are heterogeneous in their biologic behavior. The search for different morphological and molecular patterns of carcinomas in this group aims to identify prognostic and predictive subgroups, allowing for customized therapy. OBJECTIVES: To study the immunohistochemical expression of two molecules of the signaling pathway PI3K/AKT (phosphorylated AKT and PTEN) and to explore the androgen signaling pathway through the expression of androgen receptor and apocrine morphological and molecular profiles. METHODS: This study retrospectively reviewed the histological preparations and built tissue microarray with tumor samples for immunohistochemical study. We assessed histologic type, apocrine morphology, presence of in situ component, histologic and nuclear grade, estrogen and progesterone receptors and proliferative activity through the immunohistochemical expression of Ki-67. The tissue preparations were examined for PTEN, phosphorylated AKT and androgen receptor. Patients, relatives and physicians were contacted for retrieval of follow-up data. RESULTS: We studied 104 primary breast cancer patients. The expression of PTEN was reduced in 20/104 (19.2%) cases and was more frequent in tumors with positive AKT (p = 0.06). The group of tumors without loss of PTEN expression showed higher proliferative activity. AKT was positive in 71/104 (68.3%) cases and was associated with a higher degree of differentiation and with expression of androgen receptor. The androgen receptor was positive in 89/104 (85.6%) cases and was associated with lower histological grade (p = 0.018), estrogen receptor (p = 0.008) and lower proliferative activity (p = 0.001). The absence of expression of estrogen receptor (apocrine molecular profile) was identified in 41/104 cases (39.4%) and was associated with tumors of higher histologic grade. The apocrine morphological profile was identified in 71 (68.3%) cases and was associated with high histological grade and nuclear. Follow-up was possible in 55 cases and a trend for shorter disease-free survival was observed in AKT-positive and AR-negative tumors. CONCLUSIONS: Our results confirmed that HER-2-positive breast cancers are heterogeneous and indicate that differences in at least two cellular signaling pathways PI3K/AKT and androgen pathway might underliy such a heterogeneity
133

Facteurs pronostiques et prédictifs dans le cancer du sein infiltrant / Pronstic and predictive factors in invasive breast cancer

Guiu Lahaye, Séverine 16 December 2015 (has links)
Le traitement systémique adjuvant du cancer du sein infiltrant repose sur la chimiothérapie et l’hormonothérapie. Certains facteurs sont connus pour être pronostiques (âge, taille tumorale, statut ganglionnaire, grade tumoral, emboles vasculaires, statut des récepteurs hormonaux (RH) et de HER2) ou prédictifs de réponse aux traitements (RH et HER2) et influent sur nos décisions thérapeutiques. Cependant, certaines patientes récidivent malgré un traitement complet alors que d’autres vont recevoir un traitement qui aurait pu être évité de par leur bon pronostic « intrinsèque ». Nous avons cherché à identifier dans ce travail d’autres facteurs pronostiques et / ou prédictifs dans le cancer du sein infiltrant en situation néoadjuvante / adjuvante. Premièrement, nous montrons que le type histologique lobulaire, réputé pour être une histologie de cancer du sein de bon pronostic et peu chimiosensible, ne doit pas être un facteur décisionnel quant aux traitements systémiques. En situation adjuvante et concernant la chimiothérapie, la validité et l’utilité cliniques des tests génomiques nécessitent d’être évaluées spécifiquement dans ce sous-groupe. Ensuite, nous avons étudié la validité analytique, la validité clinique et l’utilité clinique de 2 classifications moléculaires des cancers du sein selon PAM50 et l’analyse immunohistochimique de biomarqueurs : récepteur œstrogène, HER2 et Ki67 avec un cut-off à 14%. Selon nos conclusions, il n’y a actuellement pas de données suffisamment robustes pour que ces 2 classifications modifient les décisions de traitement systémique. Nous avons mis en évidence un sous-groupe de tumeurs triples négatives exprimant le récepteur androgène et FOXA1 et se comportant comme des tumeurs luminales. Enfin, nous avons montré sur une large série néoadjuvante que la réponse histologique complète est un critère substitutif de survie pour les tumeurs RH négatifs / The adjuvant systemic treatment of invasive breast cancer is based on chemotherapy and endocrine therapy. Several prognostic factors (age, tumoral size, nodal status, tumoral grade, vascular embols, hormonal receptors (HR), HER2) and predictive factors of response to treatment (HR and HER2) are described and have an impact on our therapeutic decisions. However, recurrences are frequent after a complete treatment and patients could avoid such treatment because of the good “intrinsic” prognosis. In this work, we aimed to identify other prognostic and / or predictive factors for the invasive breast cancer in the neoadjuvant / adjuvant settings. Firstly, we showed that the lobular histology, considered as histology of good prognosis and low chemo sensitive, should not be a decisive factor regarding systemic therapy. In the adjuvant setting, regarding chemotherapy, clinical validity and utility of the genomic tests need to be specifically evaluated in this subgroup. Then, we studied analytical validity, clinical validity and clinical utility of 2 molecular classification of breast cancer: PAM50 and a panel of 3 biomarkers in immunohistochemistry (estrogen receptor, HER2 and Ki-67 with a cut-off of 14%). We concluded that the data were not strong enough and that the therapeutic decisions should not be influenced by these classifications. We identified a subgroup of triple negative breast cancer that express androgen receptor and FOXA1 and which behave like luminal tumors. At last, we showed in a large neoadjuvant population, that the pathological complete response is a surrogate marker of survival in RH negative tumors
134

Effets de deux xénohormones, la génistéine et la vinclozoline, sur le développement et les fonctions exocrines et endocrines des glandes salivaires submandibulaires de rats Wistar Han : influence de la période d'exposition en fonction de l'âge et du sexe / Effect of two xeno-hormones, genistein and vinclozolin on development and exocrines and endocrines functions of submandibular salivary glands of Wistar Han rats : influence of exposure period

Kouidhi-Lamloum, Wided 19 December 2012 (has links)
Les glandes salivaires sont des glandes mixtes : la salive (produit exocrine) estimpliquée dans le maintien de l’homéostasie buccale alors que les secrétions endocrines (ex :facteurs de croissance) ont un rôle physiologique (gamétogénèse, ostéogenèse,hypertension…) Chez les mammifères, elles affichent un dimorphisme sexuel qui laisseentrevoir une sensibilité éventuelle à des xeno-hormones.Ce mémoire présente l’action de la génistéine (phyto-oestrogène) et/ou de la vinclozoline(anti-androgène) sur la glande submandibulaire (SM) de rat lors d’une exposition précoce viala mère (gestation-lactation) et lors d’une exposition pendant la période de croissance (dusevrage à l’âge adulte). Les glandes SM, prélevées au stade immature et jeune adulte, ont faitl’objet d’une analyse histologique et d’une étude de marqueurs moléculaire des fonctionsendocrines et exocrines associées aux processus gustatifs. L’exposition précoce ralenti ledéveloppement de la glande SM et augmente sélectivement la préférence au sucré des malesimmatures mais pas des adultes ; l’analyse moléculaire révèle une action sélective sur lesfonctions exocrines corrélée à celle sur les préférences, ainsi qu’une action sur les fonctionsendocrines (facteurs de croissances) qui s’inverse avec l’âge. L’exposition à partir du sevrageperturbe seulement les mâles qui présentent des altérations des structures sécrétrices coupléesà des modifications d’expression des récepteurs hormonaux et facteurs de croissance, maisaussi au taux sérique de l’EGF.Cette étude identifie la glande submandibulaire comme cible de perturbateurs endocriniens etpose la question des conséquences physiologiques à terme / The salivary glands are mixed glands: saliva (exocrine product) is involved inmaintaining oral homeostasis whereas endocrine secretions (eg growth factors) have aphysiological role (gametogenesis, osteogenesis, hypertension ..). In mammals, they displaysexual dimorphism suggesting a possible susceptibility to xeno-hormones.This manuscript presents the action of genistein (phytoestrogen) and/or vinclozolin (antiandrogenic)on the submandibular gland (SM) rats when performing an early exposure via themother (pregnancy, lactation) or an exposure during the growth period (from weaning toadulthood). The SM glands, collected at immature and young adult ages, have been analyzedaccording histological aspect and expression of molecular markers of endocrine and exocrinefunctions associated with gustatory process. The early exposure disrupted the development ofthe SM gland and selectively increases the sweet preference in immature males but not inadults; molecular analysis reveals a selective action on exocrine functions related to the sweetpreferences and also an action on endocrine functions (growth factors) which reverses withage. Exposure from weaning disrupts only the male salivary glands with alterations insecretory structures coupled with changes in expression of both, sex-hormone receptors andgrowth factors, but also in serum EGF.This study identifies the submandibular gland as a target for endocrine disruptors and raisesthe question of the further physiological consequences
135

Androgenic properties of the dietary supplement 5α‑hydroxy‑laxogenin

Beer, Carolin, Keiler, Annekathrin M. 22 February 2024 (has links)
Dietary supplements sold for anabolic benefits or performance enhancement often contain substances, which are nonapproved and might lack quality controls. With regard to athletes, the inclusion of substances or methods in the prohibited list of the World Anti-Doping Agency is based on medical or scientific evidence. 5α-hydroxy-laxogenin is a synthetic spirostane-type steroid, which is contained in dietary supplements and advertised as anabolic agent. To date, evidence is missing on anabolic or androgenic activity of 5α-hydroxy-laxogenin. We investigated its androgenic potential in two in vitro bioassays. While no activity was observed in the yeast androgen screen, 5α-hydroxy-laxogenin was able to trans-activate the androgen receptor in human prostate cells in a dose-dependent manner. Interestingly, a biphasic response was observed with antagonistic properties at lower concentrations and agonistic effects at higher concentrations tested. The demonstrated androgenic properties of the higher concentrations demonstrate that further investigations should focus on the safety as well as on potential anabolic effects of 5α-hydroxy-laxogenin. This is of interest with regard to abuse for doping purposes.
136

Die Wirkung von Valproat auf die Konochenmetastasenzellen (VCaP) des Prostatakarzinoms / The effect from valproic acid at the bone metastasis cells (VCaP) of the prostate cancer

Früchtenicht, Tanja 20 September 2011 (has links)
No description available.
137

Genetic predisposition to spontaneous preterm birth:approaches to identify susceptibility genes

Karjalainen, M. (Minna) 06 December 2011 (has links)
Abstract Approximately 5.5% of all infants are born preterm (before 37 completed weeks of gestation) in Finland. Preterm birth is the cause of several life-threatening neonatal diseases and long-term morbidity. The most important risk factor for preterm birth is intrauterine infection and inflammation. Approximately 70% of preterm births have a spontaneous onset. Evidence suggests that genetic factors are involved in spontaneous preterm birth (SPTB), but knowledge about the actual genes conferring genetic predisposition is limited. The major aim of this work was to identify genetic factors that predispose to SPTB. Genome-wide linkage analysis was performed to identify genomic regions associating with SPTB in large northern Finnish families recurrently affected by SPTB. Genes near regions with linkage signals were subsequently analyzed in a Finnish case-control population of mothers and infants. Due to their roles in innate immunity, the genes encoding surfactant protein A (SP-A), SP-C, SP-D and mannose-binding lectin (MBL) were also investigated as candidates for SPTB in this population. In addition, expression of SP-C in human and mouse gestational tissues was examined. Linkage signals were detected on chromosome loci 15q26.3, Xq13.1 and Xq21.1 with the phenotype of being born preterm. In subsequent association analyses, the genes encoding the insulin-like growth factor 1 receptor (IGF1R) located within locus 15q26.3 and the androgen receptor (AR) located near locus Xq13.1 were identified as potential novel fetal SPTB susceptibility genes. These genes did not associate with SPTB in the mothers. An association was found between the Met31Thr polymorphism of the SFTPD gene encoding SP-D and SPTB in the infants. There was no association in the mothers. Polymorphisms of the genes encoding SP-A or MBL did not associate with SPTB. The Thr138Asn polymorphism of the SFTPC gene encoding SP-C did not associate with SPTB. However, this polymorphism associated strongly with the interval between preterm premature rupture of membranes and SPTB in the fetuses. Expression of SP-C was detected in human and mouse fetal membranes and placenta, and in mouse pregnant uterus. Currently, there is no effective method to prevent SPTB. The results of this study may help to clarify some of the biological mechanisms underlying SPTB and finally allow the development of specific treatment strategies for its prevention. / Tiivistelmä Suomessa syntyy noin 5,5 % lapsista ennenaikaisina eli raskauden kestettyä vähemmän kuin 37 täyttä viikkoa. Näillä lapsilla on alttius hengenvaarallisiin sairauksiin, ja osalle heistä jää pysyvä kehitysvamma. Noin 70 % ennenaikaisista syntymistä käynnistyy spontaanisti. Tärkein ennenaikaisen syntymän riskitekijä on kohdunsisäinen tulehdusreaktio. Myös perinnöllisten tekijöiden tiedetään vaikuttavan spontaanin ennenaikaisen syntymän (SEAS) käynnistymiseen, mutta alttiusgeenejä tunnetaan huonosti. Työssä pyrittiin tunnistamaan SEAS:lle altistavia perinnöllisiä tekijöitä. Perimänlaajuista kytkentäanalyysiä käyttäen etsittiin SEAS:ään liittyviä perimän kohtia tutkimalla toistuvasti ennenaikaisia syntymiä kokeneita isoja pohjoissuomalaisia perheitä. Kytkentäsignaalien lähellä olevia geenejä tutkittiin tutkimusaineistossa, joka koostui suomalaisista äideistä ja lapsista. Surfaktanttiproteiini A:ta (SP-A), SP-C:tä, SP-D:tä ja mannoosia sitovaa lektiiniä (MBL) koodaavia geenejä tutkittiin ehdokasgeeneinä SEAS:lle tässä populaatiossa, koska nämä proteiinit osallistuvat elimistön puolustukseen ja voivat siten vaikuttaa SEAS:ään liittyvään tulehdusreaktioon. Lisäksi tutkittiin SP-C:n ilmentymistä ihmisen ja hiiren sikiökalvoilla, istukassa ja kohdussa. Kytkentäsignaaleja havaittiin kromosomikohdissa 15q26.3, Xq13.1 ja Xq21.1, kun tutkittavana ilmiasuna oli ennenaikaisena syntyminen. Lisätutkimukset osoittivat, että sikiön insuliininkaltaisen kasvutekijän 1 reseptoria koodaava IGF1R-geeni (kohta 15q26.3) ja androgeenireseptorigeeni AR (lähellä kohtaa Xq13.1) ovat mahdollisia uusia SEAS:n alttiusgeenejä. Nämä geenit eivät selittäneet SEAS:ää äideissä. Sikiön SP-D:tä koodaavan geenin Met31Thr-polymorfismi tunnistettiin mahdolliseksi riskitekijäksi, mutta tämä polymorfismi ei selittänyt SEAS:ää äideissä. SP-A:ta ja MBL:ää koodaavat geenit eivät liittyneet SEAS:ään. SP-C:tä koodaavan geenin Thr138Asn-polymorfismi ei ollut yhteydessä SEAS:ään. Sikiön Thr138Asn-polymorfismi liittyi kuitenkin vahvasti sikiökalvojen puhkeamisen ja SEAS:n väliseen kestoon. SP-C:n havaittiin ilmentyvän ihmisen ja hiiren sikiökalvoilla ja istukassa sekä raskaana olevan hiiren kohdussa. Tulokset antavat uutta tietoa SEAS:n perinnöllisestä taustasta. Tämä tieto voi auttaa selvittämään sen käynnistymiseen johtavia biologisia mekanismeja ja johtaa lopulta uusiin hoitokeinoihin, joilla pystytään estämään spontaaneja ennenaikaisia syntymiä.

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