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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.
211

Applications of the Droop Cell Quota Model to Data Based Cancer Growth and Treatment Models

January 2015 (has links)
abstract: The phycologist, M. R. Droop, studied vitamin B12 limitation in the flagellate Monochrysis lutheri and concluded that its specific growth rate depended on the concentration of the vitamin within the cell; i.e. the cell quota of the vitamin B12. The Droop model provides a mathematical expression to link growth rate to the intracellular concentration of a limiting nutrient. Although the Droop model has been an important modeling tool in ecology, it has only recently been applied to study cancer biology. Cancer cells live in an ecological setting, interacting and competing with normal and other cancerous cells for nutrients and space, and evolving and adapting to their environment. Here, the Droop equation is used to model three cancers. First, prostate cancer is modeled, where androgen is considered the limiting nutrient since most tumors depend on androgen for proliferation and survival. The model's accuracy for predicting the biomarker for patients on intermittent androgen deprivation therapy is tested by comparing the simulation results to clinical data as well as to an existing simpler model. The results suggest that a simpler model may be more beneficial for a predictive use, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting. Next, two chronic myeloid leukemia models are compared that consider Imatinib treatment, a drug that inhibits the constitutively active tyrosine kinase BCR-ABL. Both models describe the competition of leukemic and normal cells, however the first model also describes intracellular dynamics by considering BCR-ABL as the limiting nutrient. Using clinical data, the differences in estimated parameters between the models and the capacity for each model to predict drug resistance are analyzed. Last, a simple model is presented that considers ovarian tumor growth and tumor induced angiogenesis, subject to on and off anti-angiogenesis treatment. In this environment, the cell quota represents the intracellular concentration of necessary nutrients provided through blood supply. Mathematical analysis of the model is presented and model simulation results are compared to pre-clinical data. This simple model is able to fit both on- and off-treatment data using the same biologically relevant parameters. / Dissertation/Thesis / Doctoral Dissertation Applied Mathematics 2015
212

Identificação e análise de expressão de RNAs intrônicos não codificadores humanos / Identification and expression analysis of human intronic noncoding RNAs

Helder Takashi Imoto Nakaya 09 March 2007 (has links)
Neste trabalho, nós mostramos estudos em larga-escala de RNAs não codificadores antisenso que são transcritos em regiões intrônicas de genes humanos. Alguns destes transcritos intrônicos possuem níveis de expressão correlacionados ao grau de diferenciação tumoral de câncer de próstata, apontando para uma relevância biológica destas mensagens em doenças complexas como o câncer. Nós também avaliamos a existência de um mecanismo comum de regulação de transcrição, compartilhado por mRNAs codificadores de proteína e RNAs intrônicos, através de análises de perfis de expressão de uma linhagem tumoral de próstata estimulada por andrógeno. A análise de ESTs e mRNAs depositados em bancos públicos de seqüências revelou mais de 55 mil RNAs Totalmente Intrônicos Não-codificadores (TIN), transcritos dos íntrons de 74% de todos os genes RefSeq únicos. Guiados por esta informação, nós desenhamos uma plataforma de oligonucleotídeos contendo sondas senso e antisenso para cada um de 7.520 transcritos TIN selecionados aleatoriamente, além de sondas para os genes codificadores de proteína correspondentes. Nós identificamos assinaturas intrônicas e exônicas de expressão tecido-específicas em fígado, próstata e rim. Os RNAs TIN antisenso mais altamente expressos eram transcritos de íntrons de genes codificadores de proteína enriquecidos na categoria ?Regulação da transcrição?. A inibição da RNA Polimerase II resultou num aumento de expressão de uma fração dos RNAs intrônicos em células em cultura, sugerindo que outras RNA Polimerases possam estar envolvidas em sua biossíntese. Um subconjunto das assinaturas intrônicas e exônicas localizadas nos mesmos loci genômicos possuíram padrões de expressão correlacionados, sugerindo que RNAs intrônicos regulem a abundância ou o padrão de uso de éxons de mensagens codificadoras de proteína. Nós identificamos diversos padrões de expressão de RNAs intrônicos, indicando que eles possam ter papéis regulatórios. Esta estratégia orientada pelo gene, que combina um microarray intrônico/exônico deve permitir análises comparativas futuras de transcrição intrônica sob várias condições fisiológicas e patológicas, avançando assim em nosso conhecimento sobre as funções biológicas destes RNAs não codificadores. / In this work, we show large-scale studies of antisense noncoding RNAs transcribed from intronic regions of human genes. The correlation of expression levels of some intronic transcripts to the degree of tumor differentiation in prostate cancer points to the biological relevance of these messages in complex diseases such as cancer. We also evaluated the existence of a common mechanism of regulation of transcription shared by protein-coding mRNAs and intronic RNAs by measuring the effect of androgen on the transcriptional profile of a prostate cancer cell line. Survey of mRNA and EST public databases revealed more than 55,000 Totally Intronic Noncoding (TIN) RNAs transcribed from the introns of 74% of all unique RefSeq genes. Guided by this information, we designed an oligoarray platform containing sense and antisense probes for each of 7,520 randomly-selected TIN transcripts plus probes for the corresponding protein-coding genes. We identified exonic and intronic tissue-specific expression signatures for human liver, prostate and kidney. The most highly expressed antisense TIN RNAs were transcribed from introns of proteincoding genes enriched in the \"Regulation of transcription\" class. RNA Polymerase II inhibition resulted in increased expression of a fraction of the intronic RNAs in cell cultures, suggesting that other RNA polymerases may be involved in their biosynthesis. A subset of intronic and protein-coding signatures transcribed from the same genomic loci has correlated expression patterns, suggesting that intronic RNAs regulate the abundance or the pattern of exon usage in protein-coding messages. We have identified diverse intronic RNA expression patterns, indicating that they may have regulatory roles. This gene-oriented approach, using a combined intronic/exonic microarray should permit further comparative analysis of intronic transcription under various physiological and pathological conditions, thus advancing current knowledge about the biological functions of these noncoding RNAs.
213

Efeito do tratamento neonatal com 17-'beta'-estradiol sobre o penis de rato em diferentes idades : aspectos estruturais do orgão e expressão do receptor de androgeno pelas celulas musculares lisas e endoteliais in vitro / Effects of neonatal 17-'beta'-estradiol treatment on the rat penis at different ages : structural aspects of the organ and androgen receptor expression by smooth muscle cells and endothelial cells in vitro

Cardoso, Lilian Caroline Vaz 13 August 2018 (has links)
Orientador: Hernandes Faustino de Carvalho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T19:33:26Z (GMT). No. of bitstreams: 1 Cardoso_LilianCarolineVaz_M.pdf: 2401125 bytes, checksum: 71ef0bb78a4f9804919ce3f2d13b8a0a (MD5) Previous issue date: 2009 / Resumo: Os hormônios androgênicos (testosterona e diidrotestosterona) regulam a diferenciação e o crescimento das estruturas penianas via receptor de andrógenos (AR), tendo este função reguladora da transcrição de genes relacionados a aspectos do desenvolvimento de indivíduos do sexo masculino. A presença de receptores de estrógenos no pênis permite assumir que o 17-â-estradiol (E2) e moléculas similares tenham efeito direto sobre sua fisiologia. De forma geral, o estrógeno tem efeito anti-androgênico, atuando sobre o eixo hipotálamo-hipófise e, assim, reduzindo a produção de testosterona pelos testículos. O estrógeno é essencial para funcionamento reprodutivo em machos, no entanto, a exposição ao estrógeno ou xenobióticos durante períodos críticos do desenvolvimento pode ter conseqüências negativas para o trato reprodutivo e para a fertilidade, através de um mecanismo conhecido como imprinting estrogênico. Um dos efeitos do imprinting estrogênico causado por altas doses de estrógeno é o comprometimento do desenvolvimento peniano. Embora seja controverso na literatura, este efeito se daria pela regulação negativa da expressão do AR e reduzida resposta aos andrógenos. Sendo assim, para estudar o efeito do imprinting estrogênico no desenvolvimento do pênis foram administrados 25 µL de óleo de milho contendo E2 a 15 mg/kg (dose alta) (Putz, et al., 2001 a, b) a ratos Wistar, nos dias 1, 3 e 5 após o nascimento e observação dos efeitos nos períodos pré-púbere (28 dias), púbere (49 dias) e adulto (90 dias). Foi feito ainda isolamento de células musculares lisas (CML), cultivadas com e sem T, e endoteliais do órgão. Para cada situação, a expressão do AR foi verificada por Western blotting e a localização por imunocitoquímica. Para o órgão e as células CML, a expressão do RNAm do AR foi analisado por Real-time PCR. Nos animais adultos foram quantificados: colágeno solúvel, hidroxiprolina e glicosaminoglicano (GAG). O tratamento neonatal com E2 resultou na queda do peso corporal, má formação do pênis, menor quantidade de hidroxiprolina e maior quantidade de GAG. A expressão do AR aumentou em animais de 28 dias e reduziu aos 90 dias. Nessas idades a marcação do AR foi menos intensa nos animais estrogenizados em todos os compartimentos penianos. Nas CML, a expressão do AR exibiu padrão diferente quando cultivadas com ou sem T. Nas células endoteliais a expressão não varia com a idade, porém diminui naquelas isoladas de animal tratado. A exposição neonatal ao E2 causa má formação do pênis o que pode estar relacionado à alteração da expressão do AR no órgão, nas CML e endoteliais presentes no mesmo. / Abstract: The androgens, testosterone and dihydrotestosterone, regulate the differentiation and growth of penile structures through the androgen receptor (AR), which regulates the transcription of genes associates with several aspects of the development of male individuals. In contrast to the prostate, the AR expression in the penis of the rat falls with age according to the androgen levels reached in the adult. The presence of estrogen receptor in the penis allows the assumption that 17-â- estradiol (E2) and similar molecules have direct effect on its physiology. It is known that estrogen has an anti-androgenic effect acting on the hypothalamic-pituitary axis reducing the production of testosterone by the testes. The estrogen is essential for reproductive function in males, but the exposure to estrogen or xenobiotics during critical periods of the development has negative consequences for the reproductive tract and fertility, through a mechanism known as estrogenic imprinting. One of the effects of estrogenic imprinting caused by high doses of estrogen is defective penile development. Although controversial in the literature, this effect occurs by down regulation of androgens receptors and reduced response to androgens. To study the effect of estrogenic imprinting on penis development, Wistar rats received subcutaneous injections of 25 µL of corn oil containing E2 at a dose of 15 mg/kg body weight (Putz, et al., 2001 a, b) on days 1, 3, and 5 after birth and observation of the effects on 28, 49 or 90 days after birth (prepubertal, pubertal and adulthood stages, respectively). Smooth muscle cells (SMC) and endothelial cells were isolated from the organ. For each situation, AR expression was verified by Western blotting and the localization by immunocitochemstry. Androgen receptor mRNA expression was done for the penis and SMC by Real-time PCR. In adult animals soluble collagen, hydroxyproline and glycosaminoglycans (GAGs) were quantified. Neonatal treatment with E2 resulted in reduction of weight and abnormal development of the penis at all ages, reduction in hydroxyproline and increase in GAGs. The AR expression increased at 28 days, but not at 90 days and in these ages the staining intensity of AR was smaller in all penile compartments. In SMC, AR expression exhibited a different expression pattern when cultured with or without T. In endothelial cells, the AR expression increased on day 28, reducing in the other ages, but without difference in comparison to control, what leds us to believe that endothelial cells do not interfere in the reduction AR expression after sexual maturation. The neonatal treatment with E2 leds to abnormal penile development what may be related to an alteration of AR expression in the organ and in their SMC and endothelial cells. / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural
214

Transcriptional regulation of the human prostatic acid phosphatase gene:tissue-specific and androgen-dependent regulation of the promoter constructs in cell lines and transgenic mice

Shan, J. (Jingdong) 09 August 2002 (has links)
Abstract Human prostatic acid phosphatase (hPAP) was the first laboratory parameter used for prostate cancer diagnosis, whereas the mechanisms behind the androgen regulation and tissue-specific expression of this prostate epithelium-specific differentiation antigen are not yet clear. In this study, a transient transfection model and transgenic animal model have been set up for functional analysis of the promoter and first intron region of the hPAP gene. The promoter constructs covering the region-734/+467 of the gene were functional in both prostatic and nonprostatic cells. Although hPAP constructs included two putative AREs with in vitro AR-binding ability at -178 and +336, androgen treatment had little effect on the promoter activity of the gene in transiently transfected cells. The hPAP fragment -734/+467 could trigger the expression of the CAT reporter gene and restrict the expression mainly in the prostates of transgenic mice. The DNA-binding site with the sequence GAAAATATGATA of a regulatory protein involved in prostate-specific and androgen receptor-dependent gene expression was identified from rPB promoter. The exact same 12 bp sequence was found in the first intron +1144/+1155 of the hPAP gene. Five homologous sequence, A, B, C, D and E, were located in the -734/+467 region of the hPAP gene, where site C and E could bind the regulatory protein in EMSA. Deletion of site C decreased the transcriptional activities significantly compared to those of corresponding wild-type constructs in LNCaP cells when androgens were present. Deletion of site E or both sites D and E increased the promoter activity in LNCaP when androgens were absent. In conclusion, androgens could not directly regulate hPAP expression via receptor-binding to the AREs in LNCaP cells. The promoter and first intron fragment -734/+467 of the hPAP gene could direct and restrict the gene expression mainly in prostate epithelium. A prostatic regulatory protein binds to multiple sites with the GAAAATATGATA or homologous sequences along the regulatory areas of the hPAP gene with different affinities, modulating the prostate-specific expression of the gene in a bidirectional manner, depending on the hormone status.
215

The role of estrogen receptors in prostate cancer development and their role in new treatment opportunities

Gehrig, Julia 20 January 2017 (has links)
No description available.
216

RELAÇÃO DO VOLUME TESTICULAR COM O NÍVEL SÉRICO DE TESTOSTERONA E CRESCIMENTO CORPORAL EM BRAHMAN DOS OITO AOS 18 MESES DE IDADE / RELATIONSHIP OF TESTICULAR VOLUME WITH SERUM TESTOSTERONE LEVEL AND BODY GROWTH IN BRAHMAN FROM 8 TO 18 MONTHS OF AGE

Miyasaki, Alex Arikawa 25 June 2014 (has links)
Made available in DSpace on 2016-01-26T18:55:42Z (GMT). No. of bitstreams: 1 Alex Miyasaki.pdf: 314698 bytes, checksum: 1d8bbeb1da7a5e1f383fc57d9361d819 (MD5) Previous issue date: 2014-06-25 / Aimed to study the relationship of testicular volume with serum testosterone level and body growth in Brahman cattle from 8 to 18 months of age, during the weaning period, kept at pasture in collective weight gain. Cattle (n = 40) aged 259.76 ± 26.15 days and weight of 239.71 ± 33.94 kg , were evaluated every 56 days during 294 days, totaling six measurements for body weight (BW), scrotal circumference (SC), thoracic perimeter (PT), body height (HC), body length (BL), body mass index (BMI), right testicular length (RTL) and left (LTL), right testicular height (RTH) and left (LTH), daily weight gain (DWG), testicular volume (TV) and serum testosterone (T). Was used analysis of variance followed by Tukey 5%. Correlations employed the method of Pearson. There were higher (P < 0.05) the third harvest (12.85 ± 0.87 months) in front for GMD x T. and higher ratings (P < 0.05) for BW, SC, EN, HC, BL, BMI, RTL, LTL, RTH, LTH and TV were obtained from the fourth harvest (14.72 ± 0.87 months). There was a correlation between T = 0.38 x PT (P <0.01); HC x T = 0.38 (P<0.01); HTD x T = 0.23 (P<0.05); HTE x T = 0.21 (P<0.01) and T x VT = 0.22 (P < 0.008). It is suggested to use the calculation of testicular volume in breeding soundness evaluation of young bulls, whose significant increase of the same may serve as a parameter for estimating the rapid increase in testosterone production, which was present at about 3.7 months before detection of a significant increase in testicular volume. / Objetivou-se estudar a relação do volume testicular com o nível sérico de testosterona e crescimento corporal em bovinos da raça Brahman dos oito aos 18 meses de idade, no período da desmama ao sobreano, mantidos à pasto em prova coletiva de ganho de peso. Os bovinos (n=40) com idade de 259,76±26,15 dias e peso de 239,71±33,94 kg, foram avaliados a cada 56 dias, durante 294 dias, totalizando seis colheitas para peso corpóreo (PC), circunferência escrotal (CE), perímetro torácico (PT), altura de cernelha (HC), comprimento corporal (CC), índice de massa corpórea (IMC), comprimento testicular direito (CTD) e esquerdo (CTE), altura testicular direito (HTD) e esquerdo (HTE), ganho médio diário de peso corpóreo (GMD), volume testicular (VT) e níveis séricos de testosterona (T). Utilizou-se a análise de variância, seguida por Tukey a 5%. Para as correlações empregou-se o método de Pearson. Houve superioridade (P<0,05) da terceira colheita (12,85 ± 0,87 meses de idade) em diante para GMD e T. Médias superiores (P<0,05) para PC, CE, PT, HC, CC, IMC, CTD, CTE, HTD, HTE e VT foram obtidas a partir da quarta colheita (14,72 ± 0,87 meses de idade). Houve correlações entre T x PT=0,38 (P<0,01); T x HC=0,38 (P<0,01); T x HTD=0,23 (P<0,05); T x HTE=0,21 (P<0,01) e T x VT=0,22 (P<0,008). Sugere-se a adoção do cálculo do volume testicular na avaliação andrológica de tourinhos jovens, cuja elevação significativa do mesmo pode servir como parâmetro para estimar o rápido aumento da produção de testosterona, a qual se fez presente por volta de 3,7 meses antes da detecção do significativo aumento do volume testicular.
217

RELAÇÃO DO VOLUME TESTICULAR COM O NÍVEL SÉRICO DE TESTOSTERONA E CRESCIMENTO CORPORAL EM BRAHMAN DOS OITO AOS 18 MESES DE IDADE / RELATIONSHIP OF TESTICULAR VOLUME WITH SERUM TESTOSTERONE LEVEL AND BODY GROWTH IN BRAHMAN FROM 8 TO 18 MONTHS OF AGE

Miyasaki, Alex Arikawa 25 June 2014 (has links)
Made available in DSpace on 2016-07-18T17:53:14Z (GMT). No. of bitstreams: 1 Alex Miyasaki.pdf: 314698 bytes, checksum: 1d8bbeb1da7a5e1f383fc57d9361d819 (MD5) Previous issue date: 2014-06-25 / Aimed to study the relationship of testicular volume with serum testosterone level and body growth in Brahman cattle from 8 to 18 months of age, during the weaning period, kept at pasture in collective weight gain. Cattle (n = 40) aged 259.76 ± 26.15 days and weight of 239.71 ± 33.94 kg , were evaluated every 56 days during 294 days, totaling six measurements for body weight (BW), scrotal circumference (SC), thoracic perimeter (PT), body height (HC), body length (BL), body mass index (BMI), right testicular length (RTL) and left (LTL), right testicular height (RTH) and left (LTH), daily weight gain (DWG), testicular volume (TV) and serum testosterone (T). Was used analysis of variance followed by Tukey 5%. Correlations employed the method of Pearson. There were higher (P < 0.05) the third harvest (12.85 ± 0.87 months) in front for GMD x T. and higher ratings (P < 0.05) for BW, SC, EN, HC, BL, BMI, RTL, LTL, RTH, LTH and TV were obtained from the fourth harvest (14.72 ± 0.87 months). There was a correlation between T = 0.38 x PT (P <0.01); HC x T = 0.38 (P<0.01); HTD x T = 0.23 (P<0.05); HTE x T = 0.21 (P<0.01) and T x VT = 0.22 (P < 0.008). It is suggested to use the calculation of testicular volume in breeding soundness evaluation of young bulls, whose significant increase of the same may serve as a parameter for estimating the rapid increase in testosterone production, which was present at about 3.7 months before detection of a significant increase in testicular volume. / Objetivou-se estudar a relação do volume testicular com o nível sérico de testosterona e crescimento corporal em bovinos da raça Brahman dos oito aos 18 meses de idade, no período da desmama ao sobreano, mantidos à pasto em prova coletiva de ganho de peso. Os bovinos (n=40) com idade de 259,76±26,15 dias e peso de 239,71±33,94 kg, foram avaliados a cada 56 dias, durante 294 dias, totalizando seis colheitas para peso corpóreo (PC), circunferência escrotal (CE), perímetro torácico (PT), altura de cernelha (HC), comprimento corporal (CC), índice de massa corpórea (IMC), comprimento testicular direito (CTD) e esquerdo (CTE), altura testicular direito (HTD) e esquerdo (HTE), ganho médio diário de peso corpóreo (GMD), volume testicular (VT) e níveis séricos de testosterona (T). Utilizou-se a análise de variância, seguida por Tukey a 5%. Para as correlações empregou-se o método de Pearson. Houve superioridade (P<0,05) da terceira colheita (12,85 ± 0,87 meses de idade) em diante para GMD e T. Médias superiores (P<0,05) para PC, CE, PT, HC, CC, IMC, CTD, CTE, HTD, HTE e VT foram obtidas a partir da quarta colheita (14,72 ± 0,87 meses de idade). Houve correlações entre T x PT=0,38 (P<0,01); T x HC=0,38 (P<0,01); T x HTD=0,23 (P<0,05); T x HTE=0,21 (P<0,01) e T x VT=0,22 (P<0,008). Sugere-se a adoção do cálculo do volume testicular na avaliação andrológica de tourinhos jovens, cuja elevação significativa do mesmo pode servir como parâmetro para estimar o rápido aumento da produção de testosterona, a qual se fez presente por volta de 3,7 meses antes da detecção do significativo aumento do volume testicular.
218

Rôles des androgènes et de leur récepteur AR dans le dimorphisme et la réparation de la myéline / Roles of Androgens and Their Receptor AR in Myelin Sexual Dimorphism and Repair

Abi Ghanem, Charly 23 September 2016 (has links)
Hormis leur implication dans les fonctions de reproduction, de développement et du maintien des caractères mâles, les androgènes (principalement la testostérone et la dihydrotestostérone, DHT) sont des hormones stéroïdiennes capables d’influencer plusieurs structures et fonctions du système nerveux. En effet, durant le développement, les androgènes ont un effet masculinisant sur le système nerveux central (SNC) le rendant sexuellement dimorphique. Chez les rongeurs mâles adultes, la substance blanche est plus volumineuse et les oligodendrocytes, cellules myélinisantes du SNC, sont plus nombreux. Cette différence est abolie après castration des mâles ; ce qui suggère l'implication de la testostérone dans le dimorphisme des oligodendrocytes et de la myéline.D’une part, mon travail de thèse visait à démontrer l’implication des androgènes et de leur récepteur (AR) dans l’établissement de ce dimorphisme. Nos résultats confirment l'implication de la testostérone et démontrent que son effet est médié par AR. En effet les corps calleux (CC) des souris mâles adultes ayant un AR non fonctionnel dans l'ensemble de l'organisme (souris Tfm) ou invalidé spécifiquement dans les cellules neurales (souris ARNesCre), présentent 20 à 30% moins d'oligodendrocytes et de surfaces myélinisées que ceux des contrôles. En outre, nos résultats montrent que ce dimorphisme apparait dès le dixième jour postnatal. De manière intéressante, le traitement pharmacologique des souriceaux mâles par un antagoniste du AR (flutamide) et des souriceaux femelles par l’agoniste d'AR (la DHT), pendant les dix premiers jours après la naissance inverse respectivement leurs profils oligodendrocytaires, suggérant un rôle organisationnel d'AR dans la substance blanche.D’autre part, mon sujet consistait à montrer l'importance de la testostérone et du AR dans la réparation de la myéline dans un modèle de démyélinisation de la moelle épinière des souris par injection stéréotaxique de lysolécithine. Nos résultats montrent que le traitement pendant 4 semaines des animaux par la testostérone permet le recrutement des oligodendrocytes et la réparation de la myéline dans les zones lésées. Il est à noter (1) qu’en absence de la testostérone ou d'AR, la réparation de la myéline est inefficace et se fait par des composants de la myéline périphérique et (2)que la présence des astrocytes semble nécessaire pour l’effet remyélinisant de la testostérone. Afin de mieux comprendre le ou les mécanisme(s) d'action(s) de la testostérone et du AR dans les processus de myélinisation et de remyélinisation, nous avons réalisé une étude transcriptomique comparative entre les animaux lésés et traités ou non avec la testostérone pour déterminer les gènes cibles et les voies de signalisations impliquées dans ces processus. Les résultats permettront probablement de définir une nouvelle cible thérapeutique pour les maladies démyélinisantes telle que la sclérose en plaques. / Androgens (mainly testosterone and dihydrotestosterone, DHT) are steroid hormones that are involved in reproduction functions, development and maintenance of male characteristics. They can also influence several structures and functions of the nervous system. Indeed, during development, androgens have a masculinizing effect on the central nervous system (CNS) making it sexually dimorphic. In addition, in adult male rodents,the white matter is larger and presents more oligodendrocytes, myelinating cells of the CNS. This difference is abolished after castration of males ; witch suggests the involvement of testosterone in the dimorphism of oligodendrocytes and myelin.One aim of my thesis was to study the involvement of androgens and their receptor (AR) in the establishment of this dimorphism. Our results confirm that testosterone is involved and demonstrate that its effect is mediated by AR. Indeed, the corpus callosum (CC) of adult male mice having a non-functional AR in the entire body (Tfm mice) or invalidated specifically in neural cells, (ARNesCre mice) have 20 to 30% fewer oligodendrocytes and myelinated area than those of controls. Moreover, our results show that this dimorphism appears early during postnatal life. Interestingly, pharmacological treatment of male pups with an AR antagonist (flutamide) and female ones with an AR agonist (DHT) during the first ten days after the birth reverses their oligodendrocytic profiles. These results suggest an organizational role of the AR in the white matter development.The aim of the second part of my study was to investigate the importance of testosterone and the AR in myelin repair in a rodent model of spinal cord demyelinationby stereotactic injection of lysolecithin. Our results show that a 4 weeks testosterone treatment allows the recruitment of oligodendrocyte and myelin repair. Interestingly, in the absence of testosterone or the AR, myelin repair was ineffeciant and was done by components of peripheral myelin. Moreover, the presence of astrocytes seems necessary for the remyelinating effect of testosterone since myelin repair was confined to astrocyte populated area.An important goal of my work is to better understand the mechanism of action of testosterone and the AR in the process of myelin formation and repair. For this, we performed a comparative transcriptomic study between animals injected or not with LPC than treated or not with testosterone to determine new target genes and signaling pathways involved in these processes. The results will probably define a new therapeutic target for demyelinating diseases such as multiple sclerosis.
219

Značaj određivanja androgenih receptora u odgovoru na hormonsku terapiju kod estrogen receptor pozitivnih pacijenata sa karcinomom dojke / The significance of determining the androgen receptors in response to hormonal therapy in estrogen receptor-positive breast cancer patients

Vidović Vladimir 04 August 2020 (has links)
<p>Glavni problem u lečenju karcinoma dojke je kako na osnovu kliničke klasifikacije i morfolo&scaron;kih osobina tumora predvideti njegovo dalje pona&scaron;anje. Vrlo često ni kombinacija standardnih prognostičkih faktora ne daje odgovor o potrebi davanja adjuvantne hemioterapije. U cilju sprovođenja adekvatne dalje terapije karcinoma dojke i otkrivanja agresivnih tipova tumora, a nakon hirur&scaron;kog lečenja, postoji stalna potreba za pronalaženjem novih pokazatelja pomoću kojih bi se identifikovale bolesnice koje imaju povećan rizik od razvoja relapsa bolesti. Ciljevi ove studije su bili da se odredi učestalost ekspresije androgenih receptora (AR) u infiltrativnom duktalnom karcinomu dojke. Da se utvrdi povezanost ekspresije AR i kliničko-patolo&scaron;kih prognostičkih faktora u infiltrativnom duktalnom karcinomu dojke. Odnos ekspresije AR i ekspresije estrogen receptora (ER), progesteron receptora (PR) i humanog epidermalnog faktora rasta (HER-2). Da se proceni povezanosti pozitivne ekspresije AR, kao i odnosa AR/ER, sa odgovorom na primenjenu hormonsku terapiju kod ER pozitivnih bolesnica. Da se proceni povezanost ekspresije AR, kao i odnosa AR/ER, sa kliničkim tokom bolesti: pojavom recidiva, metastaza, kao i smrtnim ishodom u toku petogodi&scaron;njeg perioda praćenja pacijentkinja. Istraživanjem je obuhvaćeno oko 200 pacijentkinja obolelih od infiltrativnog duktalnog karcinoma dojke, koje su operisane na Institutu za onkologiju Vojvodine u periodu 2010-2012. godine. Pacijentkinje su odabrane metodom slučajnog izbora. Ne postoji statistički značajna razlika između kliničko patololo&scaron;kih faktora i ekspresije androgenih receptora. Kod pacijentkinja sa infiltrativnim duktalnih karcinomom dojke koje su ER-/AR+ nije pokazana statistički značajna razlika u HER2 proteinskoj ekspresiji. Učestalost receptora za progesteron, estrogen, HER2, Ki-67, tripl negativne ćelija ne karakteri&scaron;u prisustvo androgenskih receptora Nije dokazana statistička značajnost za prvi i drugi stadijum bolesti duktalnog invazivnog karcinoma dojke kada se uzme u obzir kraće vreme preživljavanja kod pacijentkinja koje su primale hormonoterapiju. Statistički značajno kraće vreme preživljavanja pokazano je za treći stadijum bolesti kod pacijentkinja koje su AR i ER (&ge; 2) u odnosu na pacijentkinje kod kojih je odnos AR/ER &lt; 2, čime je za treći stadijum bolesti dokazana inicijalna hipoteza . Analize u prikazanom istraživanju nisu pokazale statističku značajnost kada se porede učestalost relapsa i smrtnog ishoda kada se posmatraju pacijentkinje sa AR pozitivnim i AR negativnim infiltrativnim duktalnim karcinomom dojke. Pokazana je statistički značajna razlika u učestalosti smrtnog ishoda između pacijenatkinja koje su lečene i inhibitorima aromataze i tamoksifenom. Zaključci ove studije bi mogli biti osnova za preporuku da se utvrđivanje ekspresije AR kod karcinoma dojke uvrsti u rutinsku praksu i sadržaj patohistolo&scaron;kog nalaza. Određivanje odnosa ekspresije AR i ER u grupi ER pozitivnih bolesnica moglo bi poslužiti kao vodič za primenu konvencionalne hormonske terapije ili, s druge strane, preporuka za terapiju antiandrogenima, sa ciljem da se izborom novih terapijskih modaliteta pobolj&scaron;a efikasnost lečenja bolesnica sa karcinomom dojke.</p> / <p>The main problem in the treatment of breast cancer is how to predict its future behavior based on the clinical classification and morphological characteristics of the tumor. Very often even a combination of standard prognostic factors does not answer the need for adjuvant chemotherapy. In order to conduct adequate further breast cancer therapy and to detect aggressive tumor types, and following surgical treatment, there is a continuing need to find new indicators to identify patients at increased risk of relapse. The objectives of this study were to determine the frequency of androgen receptor (AR) expression in infiltrative ductal breast cancer. To determine the association between AR expression and clinical-pathological prognostic factors in infiltrative ductal breast cancer. Relationship between AR expression and expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor (HER-2). To evaluate the association of positive AR expression, as well as the AR / ER ratio, with response to hormone therapy in ER positive patients. To evaluate the association of AR expression, as well as the relationship of AR / ER, with the clinical course of the disease: onset of relapse, metastasis, as well as fatal outcome during the 5-year follow-up period. The study included about 200 patients suffering from infiltrative ductal breast cancer, operated on at the Institute of Oncology of Vojvodina in the period 2010-2012. years. Patients were selected by random selection. The results there is no statistically significant difference between clinically pathologic factors and androgen receptor expression. No statistically significant difference in HER2 protein expression was shown in patients with infiltrative ductal breast cancer who are ER- / AR +. The frequency of progesterone receptors, estrogen, HER2, Ki-67, tripl negative cells do not characterize the presence of androgen receptors. No statistical significance was demonstrated for the first and second stages of ductal invasive breast cancer when considering shorter survival times in patients receiving hormone therapy. A statistically significant shorter survival time was shown for the third stage of disease in patients with AR and ER (&ge; 2) compared to patients with an AR / ER ratio of &lt;2, thus proving an initial hypothesis for the third stage of disease. The analyzes in the study presented showed no statistical significance when comparing the incidence of relapse and death when looking at patients with AR positive and AR negative infiltrative ductal breast cancer. There was a statistically significant difference in the incidence of death between patients treated with both aromatase inhibitors and tamoxifen. Conclusions of this study could be the basis for recommending that the determination of AR expression in breast cancer be incorporated into the routine practice and content of pathohistological findings. Determining the ratio of AR and ER expression in a group of ER-positive patients could serve as a guide for the administration of conventional hormone therapy or, on the other hand, a recommendation for anti-androgen therapy, with the aim of improving the effectiveness of breast cancer treatment in the choice of new therapeutic modalities.</p>
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Assessment of embryotoxicity of the antiandrogenic drugs flutamide and bicalutamide in zebrafish (Danio rerio)

Holmlund, Josefin January 2020 (has links)
Introduction: Prostate cancer is the most common type of cancer in Sweden and is often treated using antiandrogenic drug therapy. Two substances belonging to this class of pharmaceuticals are bicalutamide and flutamide. After excretion from the human body, the drug molecules enter the wastewater treatment plant (WWTP). The WWTPs are not effective enough to completely remove pharmaceutical residues, why presence of both bicalutamide and flutamide can be detected in WWTP effluent water. Previous findings: Antiandrogens have been reported to affect reproduction in adult fish, but studies regarding possible effects on the embryonic development of fish are few. Aim: The present study sought to investigate if exposure to bicalutamide or flutamide cause toxicity in the early developmental stages of zebrafish embryos, and whether negative effects occur within concentrations relevant to measured environmental levels. Method: A modified OECD FET-test was used, where additional sublethal endpoints were included and the time period for assessment extended to 144 hours post fertilization (hpf). In addition, a locomotor activity assay was performed at 144 hpf in order to observe any sub-lethal swimming behavioral effects. Results: High doses (10 mg/L) of flutamide led to 100% lethality of the zebrafish embryos but the results suggest no acute toxic effects in the high dose treatment group of bicalutamide, or of either flutamide or bicalutamide within in the low (0.1 mg/L) or intermediate (1 mg/L) treatment groups. Neither did the locomotor activity assay result in statistically significant results, although the pattern of swimming activity in the low dose groups suggests that behavioral developmental effects could be present. Conclusions: High doses of flutamide caused mortality of the embryos, but no lethal or sublethal effects were present at environmentally relevant concentrations. The modest outcome of present study however suggests that further investigation of behavioral developmental effects of antiandrogens could be of future relevance. Analysis of the expression of genes related to neuronal growth, memory and other cognitive behaviors associated with behavioral changes, would then be of interest for further studies.

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