19 resultados para HRAS
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The MET receptor tyrosine kinase is often deregulated in human cancers and several MET inhibitors are evaluated in clinical trials. Similarly to EGFR, MET signals through the RAS-RAF-ERK/MAPK pathway which plays key roles in cell proliferation and survival. Mutations of genes encoding for RAS proteins, particularly in KRAS, are commonly found in various tumors and are associated with constitutive activation of the MAPK pathway. It was shown for EGFR, that KRAS mutations render upstream EGFR inhibition ineffective in EGFR-positive colorectal cancers. Currently, there are no clinical studies evaluating MET inhibition impairment due to RAS mutations. To test the impact of RAS mutations on MET targeting, we generated tumor cells responsive to the MET inhibitor EMD1214063 that express KRAS G12V, G12D, G13D and HRAS G12V variants. We demonstrate that these MAPK-activating RAS mutations differentially interfere with MET-mediated biological effects of MET inhibition. We report increased residual ERK1/2 phosphorylation indicating that the downstream pathway remains active in presence of MET inhibition. Consequently, RAS variants counteracted MET inhibition-induced morphological changes as well as anti-proliferative and anchorage-independent growth effects. The effect of RAS mutants was reversed when MET inhibition was combined with MEK inhibitors AZD6244 and UO126. In an in vivo mouse xenograft model, MET-driven tumors harboring mutated RAS displayed resistance to MET inhibition. Taken together, our results demonstrate for the first time in details the role of KRAS and HRAS mutations in resistance to MET inhibition and suggest targeting both MET and MEK as an effective strategy when both oncogenic drivers are expressed.
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We have examined the capacity of calf thymus DNA polymerases alpha, beta, delta, and epsilon to perform in vitro translesion synthesis on a substrate containing a single d(GpG)-cisplatin adduct placed on codon 13 of the human HRAS gene. We found that DNA synthesis catalyzed by DNA polymerases alpha, delta, and epsilon was blocked at the base preceding the lesion. Addition of proliferating cell nuclear antigen to DNA polymerase delta and replication protein A to DNA polymerase alpha did not restore their capacity to elongate past the adduct. On the other hand, DNA polymerase beta efficiently bypassed the cisplatin adduct. Furthermore, we observed that DNA polymerase beta was the only polymerase capable of primer extension of a 3'-OH located opposite the base preceding the lesion. Likewise, DNA polymerase beta was able to elongate the arrested replication products of the other three DNA polymerases, thus showing its capacity to successfully compete with polymerases alpha, delta, and epsilon in the stalled replication complex. Our data suggest (i) a possible mechanism enabling DNA polymerase beta to bypass a d(GpG)-cisplatin adduct in vitro and (ii) a role for this enzyme in processing DNA damage in vivo.
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Because of subtle differences between mouse and human skin, mice have traditionally not been an ideal model to study melanoma development. Understanding of the molecular mechanisms of melanoma predisposition, however, has been greatly improved by modeling various pathway defects in the mouse. This review analyzes the latest developments in mouse models of melanoma, and summarizes what these may indicate about the development of this neoplasm in humans. Mutations of genes involved in human melanoma have been recapitulated with some unexpected results, particularly with respect to the role of the two transcripts (Ink4a and Arf) encoded by the Cdkn2a locus. Both the Ink4a/pRb and Arf/p53 pathways are involved in melanoma development in mice, and possible mechanisms of cross-talk between the two pathways are discussed. We also know from mouse models that Ras/mitogen-activated protein kinase pathway activation is very important in melanoma development, either through direct activation of Ras (e.g., Hras G12V), or via activation of Ras-effector pathways by other oncogenes (e.g., Ret, Hgf/Sf). Ras can cooperate with the Arf/p53 pathway, and probably the Ink4a/Rb pathway, to induce melanoma. These three growth regulation pathways (Ink4a/pRb, Arf/p53, and Ras/mitogen-activated protein kinase) seem to represent three major axes of melanoma development in mice. Finally, we summarize experiments using genetically modified mice that have given indications of the intensity and timing of ultraviolet radiation exposure that may be most responsible for melanoma development.
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Noonan syndrome (NS) and cardio-facio-cutaneous (CFC) syndrome are autosomal dominant disorders characterized by heart defects, facial dysmorphism, ectodermal abnormalities, and mental retardation. There is a significant clinical overlap between NS and CFC syndrome, but ectodermal abnormalities and mental retardation are more frequent in CFC syndrome. Mutations in PTPN11 and KRAS have been identified in patients with NS and those in KRAS, BRAF and MAP2K1/2 have been identified in patients with CFC syndrome, establishing a new role of the RAS/MAPK pathway in human development. Recently, mutations in the son of sevenless gene (SOS1) have also been identified in patients with NS. To clarify the clinical spectrum of patients with SOS1 mutations, we analyzed 24 patients with NS, including 3 patients in a three-generation family, and 30 patients with CFC syndrome without PTPN11, KRAS, HRAS, BRAF, and MAP2K1/2 (MEK1/2) mutations. We identified two SOS1 mutations in four NS patients, including three patients in the above-mentioned three-generation family. In the patients with a CFC phenotype, three mutations, including a novel three amino-acid insertion, were identified in one CFC patient and two patients with both NS and CFC phenotypes. These three patients exhibited ectodermal abnormalities, such as curly hair, sparse eyebrows, and dry skin, and two of them showed mental retardation. Our results suggest that patients with SOS1 mutations range from NS to CFC syndrome.
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PURPOSE: The purpose of our study was to assess whether a model combining clinical factors, MR imaging features, and genomics would better predict overall survival of patients with glioblastoma (GBM) than either individual data type. METHODS: The study was conducted leveraging The Cancer Genome Atlas (TCGA) effort supported by the National Institutes of Health. Six neuroradiologists reviewed MRI images from The Cancer Imaging Archive (http://cancerimagingarchive.net) of 102 GBM patients using the VASARI scoring system. The patients' clinical and genetic data were obtained from the TCGA website (http://www.cancergenome.nih.gov/). Patient outcome was measured in terms of overall survival time. The association between different categories of biomarkers and survival was evaluated using Cox analysis. RESULTS: The features that were significantly associated with survival were: (1) clinical factors: chemotherapy; (2) imaging: proportion of tumor contrast enhancement on MRI; and (3) genomics: HRAS copy number variation. The combination of these three biomarkers resulted in an incremental increase in the strength of prediction of survival, with the model that included clinical, imaging, and genetic variables having the highest predictive accuracy (area under the curve 0.679±0.068, Akaike's information criterion 566.7, P<0.001). CONCLUSION: A combination of clinical factors, imaging features, and HRAS copy number variation best predicts survival of patients with GBM.
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OBJETIVO: descrever o perfil epidemiológico das pacientes inscritas em lista de espera e principais indicações para o programa de ovo recepção do Hospital Regional da Asa Sul (HRAS) em Brasília, Distrito Federal. MÉTODOS: estudo descritivo prospectivo em que foram pesquisadas 330 mulheres inscritas na lista de espera do programa, das quais foram incluídas 67 mulheres independente do fator de infertilidade e que ainda não tinham sido contempladas com o tratamento. Foram excluídas 30 mulheres que moravam em outras cidades, 50 pacientes com idade superior ou igual a 50 anos, 24 pacientes que não desejavam participar do trabalho, nove pacientes que pediram exclusão do programa e 150 pacientes não localizadas por contato telefônico. As pacientes incluídas foram chamadas a responder a um questionário e tiveram seus prontuários recuperados para confirmar a realização da propedêutica necessária, a fim de estabelecer a causa da infertilidade. Os dados foram registrados e analisados pelo programa SPSS versão 12.0. RESULTADOS: o perfil epidemiológico das pacientes inclui faixa etária de 40 a 49 anos (82%), não brancas (77,6%), católicas (71,6%), casadas (59,7%), com escolaridade de primeiro ou segundo grau (76,1%), com infertilidade secundária (53,6%) por laqueadura tubária (40,3%) e que começaram a tentar engravidar até 35 anos (91%). Para estas mulheres, a principal indicação para ovo recepção foi idade no momento da inscrição no programa, seguida por baixa reserva ovariana. CONCLUSÃO: os resultados encontrados demonstram a realização indiscriminada de laqueadura tubária. O programa de ovo recepção beneficia mulheres com prognóstico reprodutivo reservado.
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OBJETIVO: Comparar a acurácia diagnóstica da histerossonografia (HSN) com a da ultrassonografia transvaginal convencional (USG) na avaliação da cavidade uterina de mulheres inférteis candidatas às técnicas de reprodução assistida (TRA). MÉTODOS: Realizou-se estudo transversal comparativo com 120 mulheres inférteis candidatas à TRA, acompanhadas no Centro de Reprodução Assistida (CRA) do Hospital Regional da Asa Sul (HRAS), Brasília - DF, no período compreendido entre agosto de 2009 e novembro de 2010. A HSN foi realizada com infusão de soro fisiológico em sistema fechado. Comparou-se o achado da HSN com o resultado da USG prévia. A cavidade uterina foi considerada anormal quando se visualizava: endométrio com espessura superior à esperada para a fase do ciclo; pólipo endometrial; mioma submucoso e alteração do formato da cavidade do útero. A análise estatística foi feita utilizando-se frequências absolutas, valores percentuais e o teste χ² com nível de significância de 5%. RESULTADOS: Observamos que 92 (76,7%) mulheres inférteis, candidatas à TRA, apresentavam cavidade uterina normal pela HSN e em 28 (23,3%) foram detectadas as seguintes alterações: 15 pólipos (12,5%), nove alterações no formato da cavidade uterina (7,5%), 6 miomas submucosos (5%), 4 espessura endometrial anormal (3,3%) para a fase do ciclo menstrual e 2 septos uterinos (1,7%); 5 mulheres apresentavam mais de uma alteração (4,2%). Enquanto a USG observou alterações da cavidade uterina apenas em 5 (4,2%) mulheres, a HSN confirmou 4 das 5 alterações detectadas pela USG e detectou alterações na cavidade uterina em outras 24 mulheres que não tinham sido detectadas na USG, ou seja, a HSN foi capaz de detectar mais alterações na cavidade uterina do que a USG, com diferença significativa (p=0,002). CONCLUSÃO: A HSN tem maior acurácia que a USG na avaliação da cavidade uterina, neste grupo de mulheres inférteis candidatas às TRA. A HSN poderá ser facilmente incorporada à propedêutica das candidatas às TRA e contribuir para reduzir as falhas de implantação embrionária.
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Large-headed total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) with metal-on-metal (MoM) bearings became popular during the last decade. Recently, it has become evident that the large-head MoM hip implants are associated with increased revision rates despite their theoretical advantages. The purpose of this study was to evaluate the early results of primary MoM hip replacements and of acetabular revisions. I analyzed retrospectively the results of four MoM implant designs and the survival rate of acetabular revisions with impaction bone grafting, as documented in the Turku University Hospital database. Further, I evaluated the correlation between femoral head size and dislocation rate, and used the Finnish Arthroplasty Register data to compare the survival of three large-head MoM THAs to analogous HRAs. The early results for the Magnum M2A–ReCap THA were good. A larger head size decreased the risk of dislocation. Articular surface replacement (ASR) THA yielded inferior results compared to analogous HRA. For two other designs the results were similar. The R3–Synergy THA yielded inferior results compared to the reference implants. The survival of acetabular reconstructions with impaction bone grafting was inferior compared to previous reports. In conclusion, the early results of the Biomet ReCap–Magnum design were promising, and large head sizes decreased the dislocation rate. The survival of different MoM hip implant designs varied. The survival of new designs and techniques may be inferior to those reported by the clinics where implants are developed. An important caveat is that early promising results of new devices may rapidly worsen. New implants need to be introduced in a controlled fashion to the market; here, arthroplasty registers are a valuable tool that needs to be used.
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Denna studies syfte är att finna sätt att producera musikinspelningar som passar lyssnare med cochleaimplantat. Frågeställningen är: Vilka perceptuella egenskaper hos cochleaimplantat bör man som musikproducent tänka på för att kunna anpassa musikinspelningar för människor med CI?För att finna de perceptuella egenskaper som cochleaimplantat, CI, har vid musiklyssning gjordes en litteraturstudie av det som skrivits kopplat till musiklyssning med CI.Resultaten visar att inspelningarna bör mixas i mono och att melodierna i musiken bör innehålla toner med stora intervall. Grundtonen i komplexa toner bör höras, och övertonerna bör kontrolleras, så att övertonsserierna inte blir alltför långa och går för högt i frekvensspektrumet. Det dynamiska omfånget i inspelningen bör inte vara alltför stort, och frekvensomfånget bör hålla sig runt 200-5000 Hz. Syntetisk rumssimulering, som t.ex. reverb, bör inte heller användas. Vidare presenteras en idé till hur man skulle kunna styra implantaten direkt elektroniskt, för att skapa musik.
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Syftet med denna uppsats är att ta reda på hur lokala kommunikationskonsulter i Falun/Borlänge-regionen ser på opinionsbildning via professionella konsulter. De centrala begrepp som avhandlas är PR, opinionsbildning och lobbying.Den teoretiska ram som omger undersökningen består av de teoribyggen som skapats av Jürgen Habermas, James E. Grunig och Larsåke Larsson. Habermas ställer sig tveksam till den demokratiska nyttan av professionell opinionsbildning, Grunig är mer positiv och Larsson ser både för- och nackdelar med PR-verksamheten. Larssons undersökning av opinionskonsulter från 2005 refereras också.Undersökningen bygger på intervjuer med ett antal kommunikationskonsulter verksamma i Falun och Borlänge. Den lokala marknaden för opinionsbildande uppdrag diskuteras, men också huruvida politiska uppdrag förser byråerna med politisk färg. Huruvida medarbetarnas engagemang är viktigt och hur hög statusen på opinionsbildande uppdrag är ventileras, samt vilka arbetsmetoder som används. Intervjuerna behandlar också förekomsten av lobbying på lokal nivå. Till slut redogör de intervjuade för sin syn på hur opinionsbildning, PR och lobbying via konsulter påverkar demokratin.Under slutsatser diskuteras resultatet i relation till den teoretiska ramen. Att PR- och reklambranscherna alltmer växer samman och att opinionsbildning är ett vanligt inslag i många projekt är ett faktum som också skymtat fram i den teoretiska ramen. Men reklam- och PR-metoder integreras också i politiken, på gott och ont. Följaktligen växer den gråzon som finns mellan de olika typerna av kommunikation och mellan opinionsbildande och icke-opinionsbildande uppdrag. Det försvårar gränsdragning och tydlighet, men skapar nya kreativa möjligheter.Att den ökade användningen av kommunikationskonsulter kanske kan bidra till en orättvis fördel för resursstarka organisationer diskuteras. Ny teknik, t.ex. Internet, kan dock eventuellt vara den motvikt som gör det möjligt även för resurssvaga grupper att höras i det offentliga samtalet. Kommunikation som maktfaktor tas även upp utifrån termer som lobbying och medias dagordningsfunktion.Några aspekter av den outnyttjade potential som PR har ventileras också. PR som metod är en outnyttjad resurs på det lokala planet, något som kan bero både på okunskap hos de lokala kunderna och ett traditionellt arbetssätt hos byråerna. Utifrån intervjusvaren framkommer att både byråerna, deras kunder och media på landsorten skulle gynnas av ett större samarbete.Resultaten av intervjuerna stöder mycket i den teoretiska ramen, medan somligt förkastas. Som sammanfattning kan sägas att opinionsbildning via konsulter kan användas för både gott och ont. Vilket som blir resultatet handlar som oftast om etik, ansvar, öppenhet och professionalitet.ABSTRACTThe primary target for this report is to find out how communication consultants in the region of Falun and Borlänge views the practice of establishing public opinions by using professional public relations consultants. The concepts in focus are PR, the moulding of public opinion and lobbying.The theoretical framework surrounding this report is the writings by Jürgen Habermas, James E. Grunig and Larsåke Larsson. Habermas has doubts as to the democratic use of professional consultants working with public opinions, Grunig has a somewhat more positive approach and Larsson sees both advantages and disadvantages in a democratic sense with the PR industry. Larssons research concerning consultants working with the moulding of public opinions from 2005 is also reviewed. The research is carried out by interviewing some communication consultants working in the Falun /Borlänge- area. The local market for commissions concerning public opinions is discussed, but also if and how political commissions are forcing a political stamp upon the firms engaging in such commissions. The importance of personal commitment in the consultants and the level of prominence commissions concerning public opinion has in the business is discussed, but also which methods is used and preferred. The interviews also deal with the practice of lobbying in the local arena. Finally the participants state their views on how the moulding of public opinion, PR and lobbying effects the democracy. Conclusively, the result is put in relation to the theories earlier mentioned. The public relations market is merging with the advertising business, that is a fact, and establishing public opinion is a common element in a lot of projects. But methods used for advertising and PR are also integrated in the political sphere, for good and bad. That has made the distinction between different kinds of communication harder, thereby enhancing the difficulties of establishing boundaries and achieving clarity. Yet at the same time it facilitates new creative opportunities.The growing use of communication consultants may contribute to unfair advantages for organisations with large economic resources. New technical development though, such as the Internet for example, may prove to simplify communication for groups with lesser economic power. Communication as an aspect of power is being discussed in terms of lobbying and the agenda setting power of media.Some aspects of the unused potential that lies within PR are also in focus in this report. PR as a method is an unused resource in the local market, which can be due to the local clients lack of knowledge but also to the traditional work carried out by the communication firms. The findings of the interviews show that both communication firms, their clients and the local media would benefit from greater cooperation.The theoretical base in this work is mostly supported by the interviews, though a few of the findings does not agree. The moulding of public opinions by professional consultants can be used for both good and bad. What the result will be is, not surprisingly, a question of ethics, responsibility, openness and professionalism.
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Syftet med denna uppsats är att ge en inblick i förhållandet mellan ljudkvalitet och den musikaliska upplevelsens kvalitet, dvs om ljudets kvalitet kan påverka en konsertbesökares helhetsupplevelse. I studien görs en enkätundersökning, där enkätdeltagaren får svara på ett antal frågor, exempelvis hur viktig ljudkvaliteten egentligen är, vilken aspekt av ljudet som bör vara tillfredsställande och vilka instrument som bör höras tydligt etc. Enkäten innehöll även två kvalitativa frågor där deltagaren får utveckla sina tankar i skriftlig form. 32 människor deltog i enkätundersökningen som ägde rum i Falun.Resultaten som forskningen gett pekar på att ljudkvaliteten är viktig för den musikaliska helhetsupplevelsen tillsammans med andra aspekter såsom bandets musikaliska prestation, scennärvaro samt scenljus etc. Majoriteten av enkätdeltagarna anser att sången är den viktigaste aspekten i musiken att höra klart och tydligt samt att det finns flera ljudaspekter (t.ex. rundgång, obalans mellan frekvenser och stark volym) som kan försämra den musikaliska upplevelsen.
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PURPOSE: To compare the diagnostic accuracy of sonohysterography (HSN) and conventional transvaginal ultrasound (USG) in assessing the uterine cavity of infertile women candidate to assisted reproduction techniques (ART). METHODS: Comparative cross-sectional study with 120 infertile women candidate to ART, assisted at Centro de Reprodução Assistida (CRA) of Hospital Regional da Asa Sul (HRAS), Brasília-DF, from August 2009 to November 2010. Sonohysterography was performed with saline solution infusion in a close system. The sonohysterography finding was compared to previous USG results. The uterine cavity was considered abnormal whenthe endometrium was found to be thicker than expectedduring the menstrual cycle and whenan endometrial polyp, a submucous myoma and an abnormal shape of the uterine cavity were observed. The statistical analysis was doneusing absolute frequencies, percentage values and the χ 2, with the level of significance set at5%. RESULTS:HSN revealed that 92 (76.7%) infertile women candidate to ARThad anormal uterine cavity, while 28 (23.3%) had the following abnormalities: 15 polyps (12.5%).
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Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB
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Noonan syndrome (NS) and Noonan-related disorders [cardio-facio-cutaneous (CFC), Costello, Noonan syndrome with multiple lentigines (NS-ML), and neurofibromatosis-Noonan syndromes (NFNS)] are a group of developmental disorders caused by mutations in genes of the RAS/MAPK pathway. Mutations in the KRAS gene account for only a small proportion of affected Noonan and CFC syndrome patients that present an intermediate phenotype between these two syndromes, with more frequent and severe intellectual disability in NS and less ectodermal involvement in CFC syndrome, as well as atypical clinical findings such as craniosynostosis. Recently, the first familial case with a novel KRAS mutation was described. We report on a second vertical transmission (a mother and two siblings) with a novel mutation (p.M72L), in which the proband has trigonocephaly and the affected mother and sister, prominent ectodermal involvement. Metopic suture involvement has not been described before, expanding the main different cranial sutures which can be affected in NS and KRAS gene mutations. The gene alteration found in the studied family is in close proximity to the one reported in the other familial case (close to the switch II region of the G-domain), suggesting that this specific region of the gene could have less severe effects on intellectual ability than the other KRAS gene mutations found in NS patients and be less likely to hamper reproductive fitness. (c) 2012 Wiley Periodicals, Inc.