1000 resultados para Breast diffusion


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: The rate of recovery from the vegetative state (VS) is low. Currently, little is known of the mechanisms and cerebral changes that accompany those relatively rare cases of good recovery. Here, we combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to study the evolution of one VS patient at one month post-ictus and again twelve months later when he had recovered consciousness. Methods fMRI was used to investigate cortical responses to passive language stimulation as well as task-induced deactivations related to the default-mode network. DTI was used to assess the integrity of the global white matter and the arcuate fasciculus. We also performed a neuropsychological assessment at the time of the second MRI examination in order to characterize the profile of cognitive deficits. Results: fMRI analysis revealed anatomically appropriate activation to speech in both the first and the second scans but a reduced pattern of task-induced deactivations in the first scan. In the second scan, following the recovery of consciousness, this pattern became more similar to that classically described for the default-mode network. DTI analysis revealed relative preservation of the arcuate fasciculus and of the global normal-appearing white matter at both time points. The neuropsychological assessment revealed recovery of receptive linguistic functioning by 12-months post-ictus. Conclusions: These results suggest that the combination of different structural and functional imaging modalities may provide a powerful means for assessing the mechanisms involved in the recovery from the VS.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tutkielman tavoitteena oli tarkastella innovaatioiden leviämismallien ennustetarkkuuteen vaikuttavia tekijöitä. Tutkielmassa ennustettiin logistisella mallilla matkapuhelinliittymien leviämistä kolmessa Euroopan maassa: Suomessa, Ranskassa ja Kreikassa. Teoriaosa keskittyi innovaatioiden leviämisen ennustamiseen leviämismallien avulla. Erityisesti painotettiin mallien ennustuskykyä ja niiden käytettävyyttä eri tilanteissa. Empiirisessä osassa keskityttiin ennustamiseen logistisella leviämismallilla, joka kalibroitiin eri tavoin koostetuilla aikasarjoilla. Näin tehtyjä ennusteita tarkasteltiin tiedon kokoamistasojen vaikutusten selvittämiseksi. Tutkimusasetelma oli empiirinen, mikä sisälsi logistisen leviämismallin ennustetarkkuuden tutkimista otosdatan kokoamistasoa muunnellen. Leviämismalliin syötettävä data voidaan kerätä kuukausittain ja operaattorikohtaisesti vaikuttamatta ennustetarkkuuteen. Dataan on sisällytettävä leviämiskäyrän käännöskohta, eli pitkän aikavälin huippukysyntäpiste.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Selektiivisten estrogeenireseptorin muuntelijoiden (serm) vaikutus rintasyöpäsolujen ja luun solujen kuolemaan Selektiiviset estrogeenireseptorin muuntelijat (SERMit) ovat ryhmä kemialliselta rakenteeltaan erilaisia yhdisteitä jotka sitoutuvat solunsisäisiin estrogeenireseptoreihin toimien joko estrogeenin kaltaisina yhdisteinä tai estrogeenin vastavaikuttajina. Tamoksifeeni on SERM –yhdiste, jota on jo pitkään käytetty estrogeenireseptoreita (ER) ilmentävän rintasyövän lääkehoidossa. Tamoksifeeni sekä estää rintasyöpäsolujen jakaantumista että toisaalta aikaansaa niiden apoptoosin eli ohjelmoidun solukuoleman muuntelemalla ER-välitteisesti kohdesolun geenien ilmentymistä. Viimeaikaiset tutkimustulokset ovat kuitenkin osoittaneet tamoksifeenilla olevan myös nopeampia, nongenomisia vaikutusmekanismeja. Tässä väitöskirjatyössä tutkimme niitä nopeita vaikutusmekanismeja joiden avulla tamoksifeeni vaikuttaa rintasyöpäsolujen elinkykyyn. Osoitamme että tamoksifeeni farmakologisina pitoisuuksina aikaansaa nopean mitokondriaalisen solukuolemaan johtavan signallointireitin aktivoitumisen rintasyöpäsoluissa. Tämän lisäksi tutkimme myös tamoksifeenin aiheuttamaan mitokondriovaurioon johtavia tekijöitä. Tutkimustuloksemme osoittavat että ER-positiivisissa rintasyöpäsoluissa tamoksifeeni indusoi pitkäkestoisen ERK-kinaasiaktivaation, joka voidaan estää 17-beta-estradiolilla. Tamoksifeenin aikaansaama nopea solukuolema on pääosin ER:sta riippumaton tapahtuma, mutta siihen voidaan vaikuttaa myös ER-välitteisin mekanismein. Sen sijaan epidermaalisen kasvutekijäreseptorin (EGFR) voitiin osoittaa osallistuvan tamoksifeenin nopeiden vaikutusten välittämiseen. Tämän lisäksi vertailimme myös estradiolin ja eri SERM-yhdisteiden kykyä suojata apoptoosilta käyttämällä osteoblastiperäisiä soluja. Pytyäksemme vertailemaan ER-isotyyppien roolia eri yhdisteiden suojavaikutuksissa, transfektoimme U2OS osteosarkoomasolulinjan ilmentämään pysyvästi joko ERalfaa tai ERbetaa. Tulostemme mukaan sekä estradioli että uusi SERM-yhdiste ospemifeeni suojaavat osteoblastin kaltaisia soluja etoposidi-indusoidulta apoptoosilta. Sekä ERalfa että ERbeta pystyivät välittämään suojavaikutusta, joskin vaikutukset erosivat toisistaan. Lisäksi havaitsimme edellä mainitun suojavaikutuksen olevan yhteydessä muutoksiin solujen sytokiiniekspressiossa. Tietoa SERM-yhdisteiden anti-ja proapoptoottisten vaikutusmekanismeista eri kohdekudoksissa voidaan mahdollisesti hyödyntää kehiteltäessä uusia kudosspesifisiä SERM-yhdisteitä.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tämän tutkimuksen päätavoitteena oli selvittää, millaiset liiketoimintamallit soveltuvat mobiilin internet-liiketoiminnan harjoittamiseen kehittyvillä markkinoilla. Tavoitteena oli myös selvittää tekijöitä, jotka vaikuttavat mobiilin internetin diffuusioon. Tutkimus tehtiin käyttäen sekä kvantitatiivista että kvalitatiivista tutkimusmenetelmää. Klusterianalyysin avulla 40 Euroopan maasta muodostettiin sisäisesti homogeenisiä maaklustereita. Näiden klustereiden avulla oli mahdollista suunnitella erityyppisille markkinoille soveltuvat liiketoimintamallit. Haastatteluissa selvitettiin asiantuntijoiden näkemyksiä tekijöistä, jotka vaikuttavat mobiilin internetin diffuusioon kehittyvillä markkinoilla. Tutkimuksessa saatiin selville, että tärkeimmät liiketoimintamallin elementit kehittyvillä markkinoilla ovat hinnoittelu, arvotarjooma ja arvoverkko. Puutteellisen kiinteän verkon todettiin olevan yksi tärkeimmistä mobiilin internetin diffuusiota edistävistä tekijöistä kehittyvillä markkinoilla.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The main objective of this dissertation is to create new knowledge on an administrative innovation, its adoption, diffusion and finally its effectiveness. In this dissertation the administrative innovation is approached through a widely utilized management philosophy, namely the total quality management (TQM) strategy. TQM operationalizes a self-assessment procedure, which is based on continual improvement principles and measuring the improvements. This dissertation also captures the theme of change management as it analyzes the adoption and diffusion of the administrative innovation. It identifies innovation characteristics as well as organisational and individual factors explaining the adoption and implementation. As a special feature, this study also explores the effectiveness of the innovation based on objective data. For studying the administrative innovation (TQM model), a multinational Case Company provides a versatile ground for a deep, longitudinal analysis. The Case Company started the adoption systematically in the mid 1980s in some of its units. As part of their strategic planning today, the procedure is in use throughout the entire global company. The empirical story begins from the innovation adoption decision that was made in the Case Company over 22 years ago. In order to be able to capture the right atmosphere and backgrounds leading to the adoption decision, key informants from that time were interviewed, since the main target was to clarify the dynamics of how an administrative innovation develops. In addition, archival material was collected and studied, available memos and data relating to the innovation, innovation adoption and later to the implementation contained altogether 20500 pages of documents. A survey was furthermore conducted at the end of 2006 focusing on questions related to the innovation, organization and leadership characteristics and the response rate totalled up to 54%. For measuring the effectiveness of the innovation implementation, the needed longitudinal objective performance data was collected. This data included the profit unit level experience of TQM, the development of the self assessment scores per profit unit and performance data per profit unit measured with profitability, productivity and customer satisfaction. The data covered the years 1995-2006. As a result, the prerequisites for the successful adoption of an administrative innovation were defined, such as the top management involvement, support of the change agents and effective tools for implementation and measurement. The factors with the greatest effect on the depth of the implementation were the timing of the adoption and formalization. The results also indicated that the TQM model does have an effect on the company performance measured with profitability, productivity and customer satisfaction. Consequently this thesis contributes to the present literature (i) by taking into its scope an administrative innovation and focusing on the whole innovation implementation process, from the adoption, through diffusion until its consequences, (ii) because the studied factors with an effect on the innovation adoption and diffusion are multifaceted and grouped into individual, organizational and environmental factors, and a strong emphasis is put on the role of the individual change agents and (iii) by measuring the depth and consistency of the administrative innovation. This deep analysis was possible due to the availability of longitudinal data with triangulation possibilities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION: Pyoderma gangrenosum (PG) is a rare autoinflammatory neutrophilic ulcerative skin disease, often developing after a trauma or surgical wounds. In the literature there are several reports of post-surgical PG (PSPG) of the breast. The authors of this article experienced an impressive case of PSPG after an aesthetic breast augmentation mastopexy. PSPG is a rare but severe complication in this elective aesthetic surgical procedure. METHOD: A systematic review of the literature was performed, focusing on PSPG after aesthetic breast surgery (augmentation mammoplasty/mastopexy). The online databases Pubmed, Medline, and Cochrane were used and additionally a Google© search was conducted. We compared the data obtained from a systematic literature review to an index case of PSPG after esthetic augmentation mammoplasty. RESULTS: The literature search identified seven articles describing eight cases of PSPG after aesthetic breast surgery. In four of these cases augmentation mammoplasty had been carried out, in two cases mastopexy and in two cases augmentation mammoplasty and mastopexy (augmentation mastopexy). The patient we treated and describe in this paper underwent an augmentation mastopexy outside our clinic. Eight patients suffered from local disease, at the site of surgical wounds, one patient had disseminated disease. Leukocytosis was present in five cases (out of nine). Eight patients had received corticosteroid treatment, one patient refused such treatment. The duration of corticosteroid treatment was on average for 41 days (range 21-60 days). In all cases, the areola had been spared. Complete healing of PSPG was observed on average after 5 months (range 1.5 months-1 year). DISCUSSION: PSPG of the breast after aesthetic breast surgery is rare, but every plastic surgeon should consider this possibility, especially if skin disease develops post-surgery, mimicking wound infection that does not respond to broad-spectrum antibiotic treatment. CONCLUSION: Although the literature does not recommend this step, implant removal is recommended by the authors because bacterial wound infection normally cannot be ruled out definitely in the early stages of disease. Additional surgical intervention should be limited to the absolute necessary and performed only under adequate systemic immunosuppressive therapy. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Calcium hydroxyapatite crystal deposition is a common disorder, which sometimes causes acute pain as calcifications dissolve and migrate into adjacent soft tissue. Intraosseous calcium penetration has also been described. We illustrate the appearance of these lesions using a series of 35 cases compiled by members of the French Society of Musculoskeletal Imaging (Société d'Imagerie Musculo-Squelettique, SIMS). The first group in our series (7 cases) involved calcification-related cortical erosions of the humeral and femoral diaphyses, in particular at the pectoralis major and gluteus maximus insertions. A second group (28 cases) involved the presence of calcium material in subcortical areas. The most common site was the greater tubercle of the humerus, accompanying a calcifying tendinopathy of the supraspinatus. In addition, an extensive intramedullary diffusion of calcium deposits was observed in four of these cases, associated with cortical erosion in one case and subcortical lesions in three cases. Cortical erosions and intraosseous migration of calcifications associated with calcific tendinitis may be confused with neoplasm or infection. It is important to recognize atypical presentations of hydroxyapatite deposition to avoid unnecessary investigation or surgery.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Oxygen vacancies in metal oxides are known to determine their chemistry and physics. The properties of neutral oxygen vacancies in metal oxides of increasing complexity (MgO, CaO, alpha-Al2O3, and ZnO) have been studied using density functional theory. Vacancy formation energies, vacancy-vacancy interaction, and the barriers for vacancy migration are determined and rationalized in terms of the ionicity, the Madelung potential, and lattice relaxation. It is found that the Madelung potential controls the oxygen vacancy properties of highly ionic oxides whereas a more complex picture arises for covalent ZnO.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Our retrospective, international study aimed at evaluating the activity and safety of eribulin mesylate (EM) in pretreated metastatic breast cancer (MBC) in a routine clinical setting. METHODS: Patients treated with EM for a locally advanced or MBC between March 2011 and January 2014 were included in the study. Clinical and biological assessment of toxicity was performed at each visit. Tumour response was assessed every 3 cycles of treatment. A database was created to collect clinical, pathological and treatment data. RESULTS: Two hundred and fifty-eight patients were included in the study. Median age was 59 years old. Tumours were Hormone Receptor (HR)-positive (73.3 %) HER2-positive (10.2 %), and triple negative (TN, 22.5 %). 86.4 % of the patients presented with visceral metastases, mainly in the liver (67.4 %). Median previous metastatic chemotherapies number was 4 [1-9]. Previous treatments included anthracyclines and/or taxanes (100 %) and capecitabine (90.7 %). Median number of EM cycles was 5 [1-19]. The relative dose intensity was 0.917. At the time of analysis (median follow-up of 13.9 months), 42.3 % of the patients were still alive. The objective response rate was 25.2 % (95 %CI: 20-31) with a 36.1 % clinical benefit rate (CBR). Median time to progression (TTP) and overall survival were 3.97 (95 %CI: 3.25-4.3) and 11.2 (95 %CI: 9.3-12.1) months, respectively. One- and 2-year survival rates were 45.5 and 8.5 %, respectively. In multivariate analysis, HER2 positivity (HR = 0.29), the presence of lung metastases (HR = 2.49) and primary taxanes resistance (HR = 2.36) were the only three independent CBR predictive factors, while HR positivity (HR = 0.67), the presence of lung metastases (HR = 1.52) and primary taxanes resistance (HR = 1.50) were the only three TTP independent prognostic factors. Treatment was globally well tolerated. Most common grade 3-4 toxicities were neutropenia (20.9 %), peripheral neuropathy (3.9 %), anaemia (1.6 %), liver dysfunction (0.8 %) and thrombocytopenia (0.4 %). Thirteen patients (5 %) developed febrile neutropenia. CONCLUSION: EM is an effective new option in heavily pretreated MBC, with a favourable efficacy/safety ratio in a clinical practice setting. Our results comfort the use of this new molecule and pledge for the evaluation of EM-trastuzumab combination in this setting. Tumour biology, primary taxanes sensitivity and metastatic sites could represent useful predictive and prognostic factors.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O Breast Imaging Reporting and Data System (BI-RADS™), do American College of hRadiology, foi concebido para padronizar o laudo mamográfico e reduzir os fatores de confusão na descrição e interpretação das imagens, além de facilitar o monitoramento do resultado final. OBJETIVO: Identificar a maneira como vem sendo utilizado o BI-RADS™, gerando informações que possam auxiliar o Colégio Brasileiro de Radiologia a desenvolver estratégias para aperfeiçoar o seu uso. MATERIAIS E MÉTODOS: Os dados foram coletados na cidade de Goiânia, GO. Foram solicitados os exames de mamografia anteriores a todas as mulheres que se dirigiram ao serviço para realização de mamografia entre janeiro/2003 e junho/2003. Foram incluídos na análise exames anteriores, realizados entre 1/7/2001 e 30/6/2003. RESULTADOS: Foram coletados 104 laudos anteriores, emitidos por 40 radiologistas de 33 diferentes serviços. Dos 104 laudos, 77% (n = 80) utilizavam o BI-RADS™. Destes, apenas 15% (n = 12) eram concisos, nenhum utilizava a estrutura e organização recomendadas pelo sistema, 98,75% (n = 79) não respeitavam o léxico e 65% (n = 51) não faziam recomendação de conduta. CONCLUSÃO: O BI-RADS™, apesar de bastante utilizado, não foi reconhecido como sistema para padronização dos laudos. Foi usado quase exclusivamente como forma de classificação final dos exames.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Invasive lobular carcinoma (ILC) is the second most prevalent histologic subtype of invasive breast cancer. Here, we comprehensively profiled 817 breast tumors, including 127 ILC, 490 ductal (IDC), and 88 mixed IDC/ILC. Besides E-cadherin loss, the best known ILC genetic hallmark, we identified mutations targeting PTEN, TBX3, and FOXA1 as ILC enriched features. PTEN loss associated with increased AKT phosphorylation, which was highest in ILC among all breast cancer subtypes. Spatially clustered FOXA1 mutations correlated with increased FOXA1 expression and activity. Conversely, GATA3 mutations and high expression characterized luminal A IDC, suggesting differential modulation of ER activity in ILC and IDC. Proliferation and immune-related signatures determined three ILC transcriptional subtypes associated with survival differences. Mixed IDC/ILC cases were molecularly classified as ILC-like and IDC-like revealing no true hybrid features. This multidimensional molecular atlas sheds new light on the genetic bases of ILC and provides potential clinical options.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background. Molecular tests for breast cancer (BC) risk assessment are reimbursed by health insurances in Switzerland since the beginning of year 2015. The main current role of these tests is to help oncologists to decide about the usefulness of adjuvant chemotherapy in patients with early stage endocrine-sensitive and human epidermal growth factor receptor 2 (HER2)-negative BC. These gene expression signatures aim at predicting the risk of recurrence in this subgroup. One of them (OncotypeDx/OT) also predicts distant metastases rate with or without the addition of cytotoxic chemotherapy to endocrine therapy. The clinical utility of these tests -in addition to existing so-called "clinico-pathological" prognostic and predictive criteria (e.g. stage, grade, biomarkers status)-is still debated. We report a single center one year experience of the use of one molecular test (OT) in clinical decision making. Methods. We extracted from the CHUV Breast Cancer Center data base the total number of BC cases with estrogen-receptor positive (ER+), HER2-negative early breast cancer (node negative (pN0) disease or micrometastases in up to 3 lymph nodes) operated between September 2014 and August 2015. For the cases from this group in which a molecular test had been decided by the tumor board, we collected the clinicopathologic parameters, the initial tumor board decision, and the final adjuvant systemic therapy decision. Results. A molecular test (OT) was done in 12.2% of patients with ER + HER2 negative early BC. The median age was 57.4 years and the median invasive tumor size was 1.7 cm. These patients were classified by ODX testing (Recurrence Score) into low-, intermediate-, and high risk groups, respectively in 27.2%, 63.6% and 9% of cases. Treatment recommendations changed in 18.2%, predominantly from chemotherapyendocrine therapy to endocrine treatment alone. Of 8 patients originally recommended chemotherapy, 25% were recommended endocrine treatment alone after receiving the Recurrence Score result. Conclusions. Though reimbursed by health insurances since January 2015, molecular tests are used moderately in our institution as per the decision of the multidisciplinary tumor board. It's mainly used to obtain a complementary confirmation supporting the decision of no chemotherapy. The OncotypeDx Recurrence Score results were in the intermediate group in 66% of the 9 tested cases but contributed to avoid chemotherapy in 2 patients during the last 12 months.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJETIVO: Avaliar artigos, na literatura, que verificam o valor preditivo positivo das categorias 3, 4 e 5 do Breast Imaging Reporting and Data System (BI-RADS®). MATERIAIS E MÉTODOS: Foi realizada pesquisa na base de dados Medline utilizando os termos "predictive value" e "BI-RADS". Foram incluídos 11 artigos nesta revisão. RESULTADOS: O valor preditivo positivo das categorias 3, 4 e 5 variou entre 0% e 8%, 4% e 62%, 54% e 100%, respectivamente. Três artigos avaliaram, concomitantemente, os critérios morfológicos das lesões que apresentaram maior valor preditivo positivo na mamografia, sendo nódulo espiculado o critério com maior valor preditivo positivo. CONCLUSÃO: Houve grande variabilidade do valor preditivo positivo das categorias 3, 4 e 5 do BI-RADS® em todos os estudos, porém foram identificadas diferenças metodológicas que limitaram a comparação desses estudos.