Die im Rahmen dieser Arbeit durchgeführten Untersuchungen zum Einfluss der Wachstumsfaktoren IGF-I, EGF und dem Zytokin IL-6 auf den Androgenrezeptor-Signalweg zeigten in verschiedenen Prostatakarzinom-zelllinien schon nach zwei Stunden eine deutliche Degradation des Androgenrezeptor-Proteins. Die ausschließlich auf Protein-Ebene stattfindende, Wachstumsfaktor-induzierte negative Regulation des Androgenrezeptors konnte durch einen schnellen Androgeneffekt wieder aufgehoben werden. Mittels Luziferase-Reportergen-Assays wurde kein Einfluss der Wachstums-faktorwirkung auf die transkriptionelle Aktivität des Androgenrezeptors nachgewiesen. Darüber hinaus konnte eine signifikant reprimierende Wirkung durch IGF-I und EGF in Kombination mit geringen Mengen DHT beobachtet werden. Weitere Resultate dieser Arbeit deuten auf einen, durch den PI3-Kinase-Signalweg vermittelten, proteasomalen Abbauprozess des Rezeptors hin. Da die Suppression der downstream gelegenen Proteinkinase Akt keine Veränderung hinsichtlich der Degradation aufwies, konzentrierte sich die weiterführende Arbeit auf eine mögliche direkte Regulation des Androgen-rezeptors durch die PI3-Kinase. Unter Verwendung von rekombinanten GST-Fusionsproteinen konnte in Interaktionsstudien unter in vitro Bedingungen eine Phosphotyrosin-unabhängige Bindung zwischen der C-SH2-Domäne der p85-Untereinheit der PI3-Kinase und dem N- und C-Terminus des Androgenrezeptors nachgewiesen werden. Durch die nähere Charakterisierung dieser Bindungsbereiche mit Hilfe von Peptidarrays und anschließenden Alanin-Substitutionen war es möglich, für den N-Terminus 18, für den C-Terminus des Androgenrezeptors 6 und für die p85-C-SH2-Domäne der PI3-Kinase 11 Aminosäuren zu identifizieren. Die durch gezielte Punktmutagenese an diesen Aminosäurepositionen hergestellten Androgenrezeptor-Einzel- und -Mehrfachmutanten wiesen in Bindungsstudien dennoch Interaktion zur PI3-Kinase auf. Eine von Anderson und Kollegen postulierte Phosphotyrosin-unabhängige Bindung der SH2-Domänen der p85-Untereinheit der PI3-Kinase durch sogenannte „basic-X-basic“-Motive wurde ebenfalls in Interaktionstests zwischen der PI3-Kinase und dem Androgenrezeptor überprüft. Aufgrund der Tatsache, dass einige der identifizierten Aminosäuren auf dem Androgenrezeptor Teil eines „basic-X-basic“-Bindungsmotives sind, wurden Kombinationsmutanten generiert, die sowohl im N-Terminus als auch im C﷓Terminus des Androgenrezeptors ein bzw. zwei zerstörte „basic-X-basic“-Motive enthielten. Untersuchungen zum Bindungsverhalten dieser Mutanten zeigten zwar weiterhin Interaktion zur p85-C-SH2-Domäne der PI3-Kinase, jedoch der durch Western-blot-Analyse überprüfte IGF-I-induzierte Degradationseffekt des Androgenrezeptor-Proteins konnte mit zwei der verwendeten Androgenrezeptor-Kombinationsmutanten nicht mehr beobachtet werden.

No description available.

Introdução: A HD está presente em aproximadamente 50% dos pacientes com OIV devido HPB e 30% dos casos não apresentarão melhora após o tratamento cirúrgico. Até o momento, nenhuma característica clínica pode predizer acuradamente quais pacientes serão beneficiados. Neste estudo nós analisamos o papel de seis marcadores moleculares na resolução da HD após a RTUP. Método: Um estudo prospectivo e controlado analisou 43 pacientes com OIV devido HPB, submetidos a RTUP de 2011 a 2012. O grupo controle foi composto por espécimes de músculo vesical de 10 pacientes com menos de 60 anos, submetidos a prostatectomia radical devido câncer de próstata, apresentando IPSS menor que 8 e volume prostático menor que 30 gramas. Todos os pacientes realizaram estudo urodinâmico no pré-operatório e com 6 meses de pós-operatório. Nós analisamos a presença, o período de início (primeira vs segunda metade do enchimento vesical) e a amplitude ( 40 cmH2O) das CVIs, assim como sua resolução após 6 meses de tratamento cirúrgico. Uma biópsia de músculo vesical foi efetuada no final da RTUP para análise do perfil de expressão gênica do NGF, NGFr, VEGF, CD-105, CHRM2 e CHRM3. Para este propósito foi utilizado a técnica de qRT-PCR. Além disso, correlacionamos variáveis clínicas pré-operatórias com a evolução da HD no pós-operatório. Resultados: A idade média dos pacientes foi 63 anos (50 a 75). A HD estava presente em 21 (48,8%) pacientes. De acordo com aferições pré-operatórias, a média de expressão gênica do NGF foi 3,3 vezes maior nos pacientes que iniciaram CVI precocemente quando comparados àqueles que iniciaram as contrações na fase final de enchimento vesical (p=0,047). A presença e a amplitude das CVIs não apresentaram correlações estatísticas com os genes estudados. Em relação a resolução da HD, a média de expressão de CHRM2 foi 2 vezes maior entre os pacientes que evoluíram com melhora da HD (p=0,072). Após 6 meses da RTUP, 77,8% dos pacientes que possuíam expressão aumentada (maior que a mediana) de CHRM2 CHRM3 evoluíram com resolução da HD (p=0,030). Além disso, pacientes com menos de 60 anos obtiveram uma probabilidade 5 vezes maior de evoluírem com melhora da HD (p=0,056) após 6 meses do tratamento cirúrgico. Conclusão: Vias neuronais parecem estar relacionadas com o período de início das CVIs durante a fase de enchimento vesical. A idade dos pacientes e a expressão de receptores muscarínicos pode ter um papel prognóstico na resolução da hiperatividade após o tratamento cirúrgico. A análise de um número maior de pacientes é necessário para confirmar estes resultados / Objective: Non-inhibited contractions (NIC) are present in about 50% of patients with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) and 30% of cases persist after surgery. To date, no clinical characteristic can predict accurately which patients are going to improve. We analyzed the role of six detrusor molecular markers in the resolution of NIC after transurethral resection of the prostate (TURP). Methods: We performed a prospective and controlled analysis of 43 patients with BOO due to BPH who underwent TURP from 2011 to 2012. The control group comprised 10 bladder specimens from patients younger than 60 years who underwent radical prostatectomy with an IPSS < 8 and prostate volume < 30 grams. All patients underwent urodynamic analysis pre and post operatively after 6 months. We analyzed the presence, time to occurrence (first vs second half of the filling phase) and grade (40 cmH2O) of NIC as well as its resolution after 6 months of surgery. A biopsy of the bladder muscle was performed at the end of TURP for analysis of nerve growth factor receptor (NGFr), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), endoglin (CD105), muscarinic cholinergic receptor 2 (CHRM2) and muscarinic cholinergic receptor 3 (CHRM3) genes expression. For this purpose, we used the quantitative real time polymerase chain reaction method (qRT-PCR). Results: Mean patient age was 63 years (50 to 75). NIC were present in 21 (48.8%) patients. According to pre-operative measures, NGF gene expression was 3.3 times greater in patients who presented early NIC as compared to those who presented late contractions (p=0.047). The presence or grade of NIC failed to present statistical correlations with the genes. With regard to the outcome, CHRM2 expression was 2.0 times greater among patients who presented resolution of NIC (p=0.072). After 6 months of TURP, 77,8% of patients with DO resolution had increased expression of CHRM2 and CHRM3 genes compared with others cases (p=0,030). Additionally, patients younger than 60 years obtained a 5.0 times more likely to evolve with improved NIC (p=0,056). Conclusion: Neural pathways seem to be more important in the time to NIC occurrence during the filling phase. Muscarinic cholinergic receptors seem to have a prognostic value in the resolution of NIC after surgery. Analysis of greater number of patients is necessary to confirm these results

Introdução: A HD está presente em aproximadamente 50% dos pacientes com OIV devido HPB e 30% dos casos não apresentarão melhora após o tratamento cirúrgico. Até o momento, nenhuma característica clínica pode predizer acuradamente quais pacientes serão beneficiados. Neste estudo nós analisamos o papel de seis marcadores moleculares na resolução da HD após a RTUP. Método: Um estudo prospectivo e controlado analisou 43 pacientes com OIV devido HPB, submetidos a RTUP de 2011 a 2012. O grupo controle foi composto por espécimes de músculo vesical de 10 pacientes com menos de 60 anos, submetidos a prostatectomia radical devido câncer de próstata, apresentando IPSS menor que 8 e volume prostático menor que 30 gramas. Todos os pacientes realizaram estudo urodinâmico no pré-operatório e com 6 meses de pós-operatório. Nós analisamos a presença, o período de início (primeira vs segunda metade do enchimento vesical) e a amplitude ( 40 cmH2O) das CVIs, assim como sua resolução após 6 meses de tratamento cirúrgico. Uma biópsia de músculo vesical foi efetuada no final da RTUP para análise do perfil de expressão gênica do NGF, NGFr, VEGF, CD-105, CHRM2 e CHRM3. Para este propósito foi utilizado a técnica de qRT-PCR. Além disso, correlacionamos variáveis clínicas pré-operatórias com a evolução da HD no pós-operatório. Resultados: A idade média dos pacientes foi 63 anos (50 a 75). A HD estava presente em 21 (48,8%) pacientes. De acordo com aferições pré-operatórias, a média de expressão gênica do NGF foi 3,3 vezes maior nos pacientes que iniciaram CVI precocemente quando comparados àqueles que iniciaram as contrações na fase final de enchimento vesical (p=0,047). A presença e a amplitude das CVIs não apresentaram correlações estatísticas com os genes estudados. Em relação a resolução da HD, a média de expressão de CHRM2 foi 2 vezes maior entre os pacientes que evoluíram com melhora da HD (p=0,072). Após 6 meses da RTUP, 77,8% dos pacientes que possuíam expressão aumentada (maior que a mediana) de CHRM2 CHRM3 evoluíram com resolução da HD (p=0,030). Além disso, pacientes com menos de 60 anos obtiveram uma probabilidade 5 vezes maior de evoluírem com melhora da HD (p=0,056) após 6 meses do tratamento cirúrgico. Conclusão: Vias neuronais parecem estar relacionadas com o período de início das CVIs durante a fase de enchimento vesical. A idade dos pacientes e a expressão de receptores muscarínicos pode ter um papel prognóstico na resolução da hiperatividade após o tratamento cirúrgico. A análise de um número maior de pacientes é necessário para confirmar estes resultados / Objective: Non-inhibited contractions (NIC) are present in about 50% of patients with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) and 30% of cases persist after surgery. To date, no clinical characteristic can predict accurately which patients are going to improve. We analyzed the role of six detrusor molecular markers in the resolution of NIC after transurethral resection of the prostate (TURP). Methods: We performed a prospective and controlled analysis of 43 patients with BOO due to BPH who underwent TURP from 2011 to 2012. The control group comprised 10 bladder specimens from patients younger than 60 years who underwent radical prostatectomy with an IPSS < 8 and prostate volume < 30 grams. All patients underwent urodynamic analysis pre and post operatively after 6 months. We analyzed the presence, time to occurrence (first vs second half of the filling phase) and grade (40 cmH2O) of NIC as well as its resolution after 6 months of surgery. A biopsy of the bladder muscle was performed at the end of TURP for analysis of nerve growth factor receptor (NGFr), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), endoglin (CD105), muscarinic cholinergic receptor 2 (CHRM2) and muscarinic cholinergic receptor 3 (CHRM3) genes expression. For this purpose, we used the quantitative real time polymerase chain reaction method (qRT-PCR). Results: Mean patient age was 63 years (50 to 75). NIC were present in 21 (48.8%) patients. According to pre-operative measures, NGF gene expression was 3.3 times greater in patients who presented early NIC as compared to those who presented late contractions (p=0.047). The presence or grade of NIC failed to present statistical correlations with the genes. With regard to the outcome, CHRM2 expression was 2.0 times greater among patients who presented resolution of NIC (p=0.072). After 6 months of TURP, 77,8% of patients with DO resolution had increased expression of CHRM2 and CHRM3 genes compared with others cases (p=0,030). Additionally, patients younger than 60 years obtained a 5.0 times more likely to evolve with improved NIC (p=0,056). Conclusion: Neural pathways seem to be more important in the time to NIC occurrence during the filling phase. Muscarinic cholinergic receptors seem to have a prognostic value in the resolution of NIC after surgery. Analysis of greater number of patients is necessary to confirm these results

Indiana University-Purdue University Indianapolis (IUPUI) / Insulin-like Growth Factor I (IGF-I) is a growth factor that stimulates both mitogenic and anabolic responses in articular chondrocytes. While it has been shown that exogenous IGF-I can regulate chondrocyte integrins, little is known regarding regulatory effects of IGF-I produced from a transiently expressed plasmid based adeno-associated virus (pAAV) vector. Because chondrocytes are using cellular machinery to overexpress IGF-I, it is of interest to see whether or not pAAV IGF-I will significantly upregulate or downregulate chondrocyte integrins. Additionally, it is of interest to know whether chondrocyte adhesion through integrins will have any regulatory effects on the production of IGF-I from the transgene. Therefore, this study will ascertain if pAAV IGF-I will have similar effects that exogenous IGF-I has on integrin regulation and if integrin silencing mechanisms will affect the production of IGF-I from the transgene. To test these hypotheses, adult articular chondrocytes were doubly transfected with the pAAV vector for IGF-I and short interference ribonucleic acid (siRNA) for integrins beta 1 and alpha V. Gene products were monitored at the transcriptional levels using quantitative real time polymerase chain reactions (qPCR) and IGF-I protein production was monitored at the translational level using enzyme linked immunoabsorbant assays (ELISAs). Adult articular chondrocytes doubly transfected were encapsulated in a three dimensional hydrogel system to simulate an in vivo environment. Samples were collected for analysis at days 2, 4, and 6 post encapsulation. Results show that IGF-I treatment with the pAAV vector does not cause significant changes in the transcriptional regulation of the beta 1 integrin in a three dimensional hydrogel system. The pAAV IGF-I vector did not cause significant regulatory changes on integrin alpha V at any time point during the experiment. Additionally, by knocking down the expression levels of integrins by using siRNA, it was shown that integrin knockdown does not have a significant regulatory effect on transcriptional or translational expression levels of IGF-I from the pAAV vector.

Thesis (PhD (Physiology (Human and animal))-- University of Stellenbosch, 2007. / Definition: Stem cells are unspecialised cells with the capacity for long-term self-renewal and the ability to differentiate into multiple cell-lineages. The potential for the application of stem cells in clinical settings has had a profound effect on the future of regenerative medicine. However, to be of greater therapeutic use, selection of the most appropriate cell type, as well as optimisation of stem cell incorporation into the damaged tissue is required. In adult skeletal muscle, satellite cells are the primary stem cell population which mediate postnatal muscle growth. Following injury or in diseased conditions, these cells are activated and recruited for new muscle formation. In contrast, the potential of resident adult stem cell incorporation into the myocardium has been challenged and the response of cardiac tissue, especially to ischaemic injury, is scar formation. Following muscle damage, various growth factors and cytokines are released in the afflicted area which influences the recruitment and incorporation of stem cells into the injured tissue. Transforming Growth Factor-β (TGF-β) is a member of the TGF-β-superfamily of cytokines and has at least three isoforms, TGF-β1, -β2, and -β3, which play essential roles in the regulation of cell growth and regeneration following activation and stimulation of receptor-signalling pathways. By improving the understanding of how TGF-β affects these processes, it is possible to gain insight into how the intercellular environment can be manipulated to improve stem cell-mediated repair following muscle injury. Therefore, the main aims of this thesis were to determine the effect of the three TGF-β isoforms on proliferation, differentiation, migration and fusion of muscle progenitor cells (skeletal and cardiac) and relate this to possible improved mechanisms for muscle repair. The effect of short- and long-term treatment with all three TGF-β isoforms were investigated on muscle progenitor cell proliferation and differentiation using the C2C12 skeletal muscle satellite and P19 multipotent embryonal carcinoma cell-lineages as in vitro model systems. Cells were treated with 5 ng/mℓ TGF-β isoforms unless where stated otherwise. In C2C12 cells, proliferating cell nuclear antigen (PCNA) expression and localisation were analysed, and together with total nuclear counts, used to assess the effect of TGF-β on myoblast proliferation (Chapter 5). The myogenic regulatory factors MyoD and myogenin, and structural protein myosin heavy chain (MHC) were used as protein markers to assess early and terminal differentiation, respectively. To establish possible mechanisms by which TGF-β isoforms regulate differentiation, further analysis included determination of MyoD localisation and the rate of MyoD degradation in C2C12 cells. To assess the effect of TGF-β isoforms on P19 cell differentiation, protein expression levels of connexin-43 and MHC were analysed, together with the determination of embryoid body numbers in differentiating P19 cells (Chapter 6). Furthermore, assays were developed to analyse the effect of TGF-β isoforms on both C2C12 and P19 cell migration (Chapter 7), as well as fusion of C2C12 cells (Chapter 8). Whereas all three isoforms of TGF-β significantly increased proliferation of C2C12 cells, differentiation results, however, indicated that especially following long-term incubation, TGF-β isoforms delayed both early and terminal differentiation of C2C12 cells into myotubes. Similarly, myocyte migration and fusion were also negatively regulated following TGF-β treatment. In the P19 cell-lineage, results demonstrated that isoform-specific treatment with TGF-β1 could potentially enhance differentiation. Further research is however required in this area, especially since migration was greatly reduced in these cells. Taken together, results demonstrated variable effects following TGF-β treatment depending on the cell type and the duration of TGF-β application. Circulating and/or treatment concentrations of this growth factor could therefore be manipulated depending on the area of injury to improve regenerative processes. Alternatively, when selecting appropriate stem or progenitor cells for therapeutic application, the effect of the immediate environment and subsequent interaction between the two should be taken into consideration for optimal beneficial results.

Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. One of the common forms of articular cartilage disease which has a huge impact on patient's life is arthritis. Research on cartilage cell/tissue engineering will help patients to improve their physical activity by replacing or treating the diseased/damaged cartilage tissue. Cartilage cell, called chondrocyte is embedded in the matrix (Lacunae) and has round shape in vivo. The in vitro monolayer culture of primary chondrocyte causes morphological change characterized as dedifferentiation. Transforming growth factor-beta (TGF-β), a cytokine superfamily, regulates cell function, including differentiation and proliferation. The effect of TGF-β1, 2, 3, and their manipulated forms in biological regulation of primary chondrocyte was investigated in this work. A novel method was developed to isolate and purify the primary chondrocytes from knee joint of neonate Sprague-Dawley rat, and the effect of some supplementations such as hyaluronic acid and antibiotics were also investigated to provide the most appropriate condition for in vitro culture of chondrocyte cells. Addition of 0.1mg/ml hyaluronic acid in chondrocyte culture media resulted an increase in primary chondrocyte proliferation and helped the cells to maintain chondrocytic morphology. TGF-β1, 2 and 3 caused chondrocytes to obtain fibroblastic phenotype, alongside an increase in apoptosis. The healing process of the wound closure assay of chondrocyte monolayers were slowed down by all three isoforms of TGF-β. All three types of TGF-β negatively affected the strength of chondrocyte adhesion. TGF-β1, 2 and 3 up regulated the expression of collagen type-II, but decreased synthesis of collagen type-I, Chondroitin sulfate glycoprotein, and laminin. They did not show any significant change in production of S-100 protein and fibronectin. TGF-β2, and 3 did not change expression of integrin-β1 (CD29), but TGF-β1 decreased the secretion of this adhesion protein. Manipulated TGF-β showed huge impact on formation of fibroblast like morphology of chondrocytes with chondrocytic phenotype. These isoforms also decreased the expression of laminin, chondroitin sulfate glycoprotein, and collagen type-I, but they increased production of collagen type-II and did not induce synthesis of fibronectin and S-100 protein. In addition, the strength of cell adhesion on solid surface was reduced by manipulated TGF-β. Only manipulated form of TGF-β1 and 2 could increase the proliferation rate. Manipulation of TGF-β did not up regulate the expression of integrin-β1 in planar culture system. The implications of this R&D work are that the manipulation of TGF-β by combination of TGF-β1, 2, and 3 can be utilized in production of superficial zone of cartilage and perichondrium. The collagen, fibronectin and hyaluronic acid could be recruited for the fabrication of a biodegradable scaffold that promotes chondrocyte growth for autologous chondrocyte implantation or for formation of cartilage.

<p>Dijabetesna retinopatija je među vodećim uzročnicima stečenog slepila, kako u razvijenim zemljama, tako i zemljama u razvoju. Dijabetesna retinopatija je jedna od<br />najče&scaron;ćih komplikacija Dijabetes Mellitus-a. U sklopu dijabetesne retinopatije jedan od najranijih razloga koji dovodi do pada vidne o&scaron;trine je dijabetični makularni edem (DME). Pad vidne o&scaron;trine kod pacijenata sa dijabetesom naru&scaron;ava njihov kvalitet života i umanjuje radnu sposobnost. Dosada&scaron;nji oblik lečenja laserfotokoaguacijom makule, nije dao zadovoljavajuće rezultate. U novije vreme sve vi&scaron;e je zastupljeno farmakolo&scaron;ko lečenje edema koje podrazumeva intrvitrealnu aplikaciju lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta (VEGF inhibitori), koji dovodi do stabilizacije zidova krvnih sudova.&nbsp;<br />Cilj ove studije je da se ispita efikasnost lečenja DME uz pomoć intravitrealno aplikovanih lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta u odnosu na konvencionalno do sada priznato lečenje laserfotokogulacijom makule.&nbsp;<br />Efikasnost lečenja je procenjivana na dva načina: anatomski, na osnovu smanjenja centralne makularne debljine izražene u &mu;m, merene metodom optičke koherentne tomografije, i funkcionalno, na osnovu pobolj&scaron;anja vidne o&scaron;trine koja je izražavana u log MAR jedinicama. U ovoj prospektivnoj, randomiziranoj kliničkoj studiji sa minimumom praćenja od 6 meseci, u eksperimentalnoj grupi tretiran je 51 pacijent,<br />odnosno 84 oka aplikacijom bevacizumaba (anti VEGF agens) u dozi od 1,25 mg, sa ili bez dodatnog laser tretmana.&nbsp;<br />Uz prosečno 2,46 inekcije postignuta je prosečna redukcija centralne makularne debljine od 139,15 &mu;m.&nbsp; Dobijene vrednosti su nakon svake aplikovane doze su značajno bolje u odnosu na početnu. Edemi sa većom centralnom makularnom debljinom su zahtevali tretman sa većim brojem inekcija. Kod većih edema je postignuta i veća redukcija centralne makularne debljine. U odnosu na vidnu o&scaron;trinu u eksperimentalnoj grupi postignuto je pobolj&scaron;anje od 0,135 log MAR jedinica. Efekat lasera kao samostalne terapije u kontrolnoj grupi (50 pacijenata, 92 oka) nije bio<br />značajan ni u pogledu smanjenja centralne makularne debljine kao ni na osnovu pobolj&scaron;nja vidne o&scaron;trine. Tretman bevacizumabom samostalno ili u kombinaciji sa laserom je efikasniji u tretmanu DME u odnosu na konvencionalni tretman laserfotokoaguacijom koji potvrđeno dovodi do stabilizacije stanja. Značaj ove studije je potvrda efikasnosti i bezbednosti jednog novog oblika lečenja koji samostalno ili u kombinaciji sa laser tretmanom predstavlja novi protokol lečenja dijabetičnog makularnog edema.</p> / <p>Diabetic retinopathy is among the leading causes of acquired blindness in developed countries, as well as in developing countries. Diabetic retinopathy is one of the most frequent Diabetes Mellitus complications. Within diabetic retinopathy, diabetic macular edema (DME) is one of the earliest causes of the loss of visual acuity. Impaired vision causes decline in life quality in diabetic patients and it decreases their<br />working ability. Up to this date, laser photocoagulation treatment has not given<br />satisfactory results. Recently, new promising treatment forms have emerged, including the intravitreal application of vascular endothelium growth factor (VEGF inhibitors), which lead to stabilization of the vessel wall. The aim of this study is to evaluate the efficacy of DME treatment consisting of intravitreal&nbsp; VEGF inhibitor application alone or as a part of combined treatment (intravitreal VEGF inhibitor plus laser photocoagulation) compared with conventional laser treatment alone. The effect of treatment was evaluated according to morphological parameters by measuring central macular thickness (CMT) in &mu;m with optical coherence tomography, and according to functional parameter by visual acuity in log MAR scale. In this prospective randomized clinical trial, with minimum follow up of 6 months, in experimental group 51 patient, or 84 eyes were treated with bevacizumab (VEGF inhibitor) in 1.25 mg dosage, alone or in combination with laser. The mean reduction in was 139.15 &mu;m, which was achieved with 2.46 doses on average. The difference between the final and initial CMT values after each dos age was tatistically significant.<br />Edemas with high central macular thickness required high number of intraviteal<br />aplicatons and the reduction was higher. In our study, mean visual acuity improved significantly in 0.135 log MAR. In control group (50 patient, 92 eyes) treated with laserphotocolagulation alone, the effect on visual acuity and central acular thickness was not statistically significant. The treatment with bevacizumab alone or in combined<br />treatment is more effective in treating DME than conventional macular laser treatment alone, from both - anatomical and functional perspective. The importance of this study is confirmation of the efficacy and safety of a new form of treatment and the introduction of a new protocol for the treatment of diabetic macular edema.</p>

Introdução: Crianças nascidas pequenas para a idade gestacional (PIG) apresentam maior risco de permanecerem com baixa estatura na vida adulta. Os fatores de crescimento insulino-símile tipo 1 e 2 (IGF-1 e IGF-2) são os principais fatores endócrinos determinantes do crescimento fetal. A maioria das ações conhecidas destes hormônios é mediada via um receptor tirosina quinase, conhecido como IGF-1R. As mutações inativadoras e deleções do gene do IGF1R em heterozigose vêm sendo relatadas de forma crescente nos últimos 9 anos em pacientes com história de déficit de crescimento pré e pós-natal. Postula-se que pelo menos 2 a 3% das crianças nascidas PIG poderiam apresentar defeitos no IGF1R. O quadro clínico destes pacientes apresenta grande variabilidade quanto à gravidade do retardo de crescimento pré- e pós-natal e aos parâmetros hormonais. Objetivo: Caracterizar in vitro a resistência ao IGF-1 de pacientes com defeitos no IGF1R, identificados em nosso ambulatório. Material e métodos: Desenvolvemos cultura de fibroblastos de 2 controles (C1 e C2) e de 4 pacientes nascidos PIG (SGA1, SGA2, SGA3 e SGA4) com suspeita de insensibilidade ao IGF-1 por ausência de recuperação do crescimento na vida pós natal. Destes pacientes, um paciente (SGA1) era portador de mutação missense em heterozigose no gene IGF1R (p.Arg511Trp) e os demais apresentavam baixa expressão dos IGF1R em leucócitos periféricos quando avaliados por PCR em tempo real. Um destes pacientes (SGA2) apresentava também a variante alélica p.Gly6Arg do IGF1R em heterozigose, alteração esta encontrada também em controles e familiares sem déficit de crescimento. As ações do IGF-1 foram determinadas por ensaios de proliferação, análise da expressão do IGF-1R e estudos de fosforilação de proteínas da via de sinalização do IGF-1 em fibroblastos (via PI3K). Resultados: As linhagens SGA1, SGA2, SGA3 e SGA4 proliferaram respectivamente 55%, 66%, 64% e 28% a menos sob estímulo de IGF-1 em relação ás linhagens controles. No estudo da expressão do RNAm do IGF1R por PCR em tempo real, foi observada redução na expressão do IGF1R nas linhagens SGA2, SGA3 e SGA4 em relação aos controles, assim como o conteúdo total da proteína IGF-1R. Por outro lado, a linhagem SGA1 mostrou expressão aumentada do IGF1R e no conteúdo da proteína em relação aos controles. Em relação á ativação da via PI3K, todas as linhagens dos pacientes apresentaram menor fosforilação de AKT após estímulo com IGF-1, quando comparadas com as linhagens controles. Conclusão: Demonstramos a presença de insensibilidade parcial ao IGF-1 nas linhagens estudadas. A baixa expressão do IGF1R observada em leucócitos periféricos nas linhagens SGA2, SGA3 e SGA4 foi confirmada em fibroblastos tanto em nível de RNAm quanto da sua proteína. Nestas linhagens a insensibilidade ao IGF-1 é secundária a diminuição da expressão deste receptor. Em contraste a na linhagem com a mutação p.Arg511Trp (SGA1) observou-se expressão normal do IGF-1R na superfície celular. Pacientes com alterações no gene IGF1R não apresentam um fenótipo característico que os diferencie de outras crianças nascidas PIG sem alterações neste gene, mostrando a importância dos estudos moleculares neste grupo de pacientes / Small for gestational age (SGA) children are at a greater risk of having a short stature in adulthood. The type 1 and 2 insulin-like growth factors (IGF-1 and IGF-2) are the main endocrine factors determining fetal growth, and most of the known actions of these hormones are mediated via a receptor tyrosine kinase, IGF-1R. Inactivating mutations and deletions of the IGF1R gene in heterozygosis have been reported with increasing frequency in the last 9 years in patients with a history of a failure to thrive pre- and postnatally. It is postulated that at least 2-3% of the children born SGA could be defective for the IGF1R. The clinical presentation of these patients is highly variable with regard to the severity of growth retardation and pre- and post-natal hormonal parameters. Objectives: The goal of this study was to identify the in vitro insensitivity to IGF-1 in patients with defects in IGF1R. Methods: We developed fibroblast cultures from two controls (C1 and C2) and 4 patients born SGA (SGA1, SGA2, SGA3 and SGA4) with a suspected insensitivity to IGF-1 by the absence of catch-up growth during their postnatal life. Of these patients, one (SGA1) carried a heterozygous missense mutation in the IGF1R gene (p.Arg511Trp), and the others exhibited low expression levels of IGF1R in their peripheral leukocytes, as evaluated using real-time PCR. One of these patients (SGA2) was also heterozygous for the allelic variant p.Gly6Arg of IGF1R, an alteration also found in the controls and family members not displaying growth restriction. The actions of IGF-1 were determined using proliferation assays, an analysis of the expression of IGF- 1R and phosphorylation studies of proteins of the IGF-1 signaling pathway in fibroblasts (via PI3K).Results: The SGA1, SGA2, SGA3 and SGA4 fibroblasts proliferated 55%, 66%, 64% and 28%, respectively, less under the stimulation of IGF-1 compared to the control lines. Using real-time PCR, the IGF1R mRNA expression showed reduced levels of IGF1R in the SGA2, SGA3 and SGA4 cells compared to the controls, and the total IGF-1R protein was also decreased in these cells. Moreover, the SGA1 cells showed increased expression levels of IGF1R mRNA and protein compared to the controls. In relation to the activation of PI3K, all of the cells showed decreased phosphorylation of AKT after the stimulation with IGF-1 compared to the control cells. Conclusion: We demonstrated the presence of a partial insensitivity to IGF-1 in the studied samples. The low expression of IGF1R observed in the peripheral leukocytes in the SGA2, SGA3 and SGA4 fibroblasts was confirmed at both the mRNA and protein levels, and the Andréa de Castro Leal Doutorado insensitivity of the cells to IGF-1 is secondary to the decreased expression of the receptor. In contrast, the cells with the mutation p.Arg511Trp (SGA1) displayed normal IGF-1R expression on the cell surface. The patients with alterations in the IGF1R gene do not exhibit a characteristic phenotype that differentiates them from other children born SGA and with no changes in this gene, thus showing the importance of molecular studies for this group of patients

O hormônio adrenocorticotrópico, ACTH, regula função (esteroidogênese) e proliferação das células da córtex das glândulas adrenais através de um único receptor específico, ACTHR, que pertence à superfamília GPCR (G-protein coupled receptors). Embora o ACTHR tenha sido clonado há 8 anos, os mecanismos moleculares das ações mitogênica e anti-mitogênica de ACTH permanecem obscuros, cuja elucidação é objeto de estudo deste trabalho. A abordagem experimental consistiu na clonagem do ACTHR de células adrenocorticais Y-1 de camundongo e expressão funcional em fibroblastos 3T3 e células AR-1. Clones transfectantes, expressando estavelmente ACTHR, mostraram-se responsivos a ACTH através de: a) ativação de adenilato ciclase e b) indução de genes das famílias fos e jun. Por outro lado, medidas de síntese de DNA e proliferação celular indicam que ACTH não tem nenhum efeito mitogênico ou anti-mitogênico nos transfectantes ACTHR. O gene c-fos foi usado como alvo para testar vias de transdução de sinal ativadas por ACTH nos transfectantes 3T3 ACTHR. Estes testes mostraram que PKA, PKC e MAPK tem pouca ou nenhuma participação na indução de c-fos por ACTH nos clones 3T3 ACTHR, sugerindo que ACTHR pode ativar vias ainda não identificadas e motivando a busca de novas vias ativadas por ACTH nas células Y-1. Verificou-se que células Y-1 apresentam níveis constitutivamente elevados de AKT/PKB ativada (fosforilada), dependentes de PI3K e SRC, e que ACTH promove rápida desfosforilação de AKT via Gs/Adenilato Ciclase/cAMP/PKA. Ao promover a inativação de AKT, ACTH promove simultaneamente a indução da proteína p27'IND.Kip1', um mecanismo que contribui para a atividade anti-mitogênica de ACTH. / The adrenocorticotropic hormone, ACTH, regulates both function and proliferation of adrenocortical cells binding to a specific receptor, ACTHR, which belongs to superfamily of GPCR (G-protein coupled receptors). ACTHR was cloned a few years ago, but the molecular mechanisms underlying the mitogenic and anti-mitogenic actions of ACTH remain unknown, whose elucidation is aim of this project. The experimental approach was to clone the ACTHR from mouse Y-1 adrenocortical cells and to express the functional receptor in Balb 3T3 fibroblasts and AR-1 cells. Transfectant clones stably expressing the ACTHR respond to ACTH treatments by: a) adenylate cyclase activation and b) induction of fos and jun genes. On the other hand, experiments of DNA synthesis and cellular proliferation showed that ACTH has not mitogenic or anti-mitogenic effects in ACTHR transfectants. c-fos gene was used as a target to test signal transduction pathways activated by ACTH into 3T3 ACTHR transfectants. The results showed that PKA, PKC and MAPK have no relevant contribution on the ACTH c-fos induction in 3T3 ACTHR transfectants suggesting that ACTHR can activate signal transduction pathways still not identified. This conclusion prompted us to search for another signal transduction pathways triggered by ACTHR in Y-1 adrenocortical cells. This search led to the detection of high constitutive levels of activated AKT/PKB in Y-1 adrenocortical cells, which are dependent on PI3K and SRC. ACTH causes a strong and rapid downregulation of activated AKT in a Gs/Adenylate Cyclase/cAMP/PKA dependent manner. Apparently, dephosphorylation of AKT promoted by ACTH releases transcription factors that induce p27'IND.Kip1', a likely mechanism underlying ACTH anti-mitogenic effects in adrenocortical cells.