939 resultados para Richter, Dave
Resumo:
Tumor budding in colorectal cancer is likened to an epithelial-mesenchymal transition (EMT) characterized predominantly by loss of E-cadherin and up-regulation of E-cadherin repressors like TWIST1 and TWIST2. Here we investigate a possible epigenetic link between TWIST proteins and the tumor budding phenotype. TWIST1 and TWIST2 promoter methylation and protein expression were investigated in six cell lines and further correlated with tumor budding in patient cohort 1 (n = 185). Patient cohort 2 (n = 112) was used to assess prognostic effects. Laser capture microdissection (LCM) of tumor epithelium and stroma from low- and high-grade budding cancers was performed. In colorectal cancers, TWIST1 and TWIST2 expression was essentially restricted to stromal cells. LCM results of a high-grade budding case show positive TWIST1 and TWIST2 stroma and no methylation, while the low-grade budding case was characterized by negative stroma and strong hypermethylation. TWIST1 stromal cell staining was associated with adverse features like more advanced pT (p = 0.0044), lymph node metastasis (p = 0.0301), lymphatic vessel invasion (p = 0.0373), perineural invasion (p = 0.0109) and worse overall survival time (p = 0.0226). Stromal cells may influence tumor budding in colorectal cancers through expression of TWIST1. Hypermethylation of the tumor stroma may represent an alternative mechanism for regulation of TWIST1.
Resumo:
IL-23 is a heterodimeric cytokine involved in inflammatory diseases; its role in cancer progression is controversial. Here we analyse the expression of IL-23 subunits (p40 and p19) and IL-23R in colorectal cancer with regard to disease progression, clinical-pathological and molecular aspects. Immunohistochemistry for IL-23p19, IL-23p40, IL-23R and CD8 was performed on a multi-punch tissue microarray of 195 colorectal cancers (cohort 1), matched normal tissue, adenoma and lymph node metastases. Results were compared with clinical-pathological features and CD8+ T-cell counts, then validated on two patient cohorts (cohort 2: n=341, cohort 3: n=139). Cytoplasmic/membranous expression of IL-23 (p19 and p40 subunits) and IL-23R, respectively were over-expressed in carcinomas versus adenomas and normal tissues (p<0.0001) but were reduced in lymph node metastases (p<0.0001). Nuclear IL-23p19 expression was observed in 23.1% and was associated with early TNM stage (p=0.0186), absence of venous (p=0.0124) and lymphatic invasion (p=0.01493), favorable survival (p=0.014) and absence of distant metastasis (p=0.0146; specificity: 100%). This unexpected cellular localization was confirmed by cell fractionation. The beneficial effect of nuclear IL-23p19 was restricted to tumours with CD8+ high counts. Results were validated on Cohorts 2/3. This multicenter study underlines the possible CD8(+)--dependency and beneficial effect of nuclear IL-23p19 on overall patient survival.
Resumo:
BCL2 is a target of somatic hypermutation in t(14;18) positive and also in a small fraction of t(14;18) negative diffuse large B-cell lymphoma (DLBCL), suggesting an aberrant role of somatic hypermutation (ASHM). To elucidate the prevalence of BCL2 mutations in lymphomas other than DLBCL, we Sanger-sequenced the hypermutable region of the BCL2 gene in a panel of 69 mature B-cell lymphomas, including Richter's syndrome DLBCL, marginal-zone lymphomas, post-transplant lymphoproliferative disorders, HIV-associated and common-variable immunodeficiency-associated DLBCL, all known to harbour ASHM-dependent mutations in other genes, as well as 16 t(14,18) negative and 21 t(14;18) positive follicular lymphomas (FLs). We also investigated the pattern of BCL2 mutations in longitudinal samples from 10 FL patients relapsing to FL or transforming to DLBCL (tFL). By direct sequencing, we found clonally represented BCL2 mutations in 2/16 (13%) of t(14;18) negative FLs, 2/16 (13%) HIV-DLBCLs, 1/9 (11%) of Richter's syndrome DLBCL, 1/17 (6%) of post-transplant lymphoproliferative disorders and 1/2 (50%) common-variable immunodeficiency-associated DLBCL. The proportion of mutated cases was significantly lower than in FLs carrying the t(14;18) translocation (15/21, 71%). However, the absence of t(14;18) by FISH or PCR and the molecular features of the mutations strongly suggest that BCL2 represents an additional target of ASHM in these entities. Analysis of the BCL2 mutation pattern in clonally related FL/FL and FL/tFL samples revealed two distinct scenarios of genomic evolution: (i) direct evolution from the antecedent FL clone, with few novel clonal mutations acquired by the tFL major clone, and (ii) evolution from a common mutated long-lived progenitor cell, which subsequently acquired distinct mutations in the FL and in the relapsed or transformed counterpart. Copyright © 2014 John Wiley & Sons, Ltd.
Resumo:
From early colonial encounters to the ecological disasters of the twenty-first century, the performativity of contact has been a crucial element in the political significance of the beach. Conceptualising the beach as a creative trope and as a socio-cultural site, as well as an aesthetically productive topography, this collection examines its multiplicity of meanings and functions as a natural environment engendering both desire and fear in the human imagination from the Victorian period to the present. The contributors examine literature, film, and art, in addition to moments of encounter and environmental crisis, to highlight the beach as a social space inspiring particular codes of behaviour and specific discourses, as a geographical frontier between land and water, as an historical site of contact and conflict, and as a vacationscape promising regeneration and withdrawal from everyday life. The diversity of the beach is reflected in the geographical range, with essays on locales and texts from Britain, Ireland, the Caribbean, South Africa, the United States, Polynesia, and New Zealand. Focusing on the changed function of the beach as a result of processes of industrialisation and the rise of a modern leisure and health culture, this interdisciplinary volume theorises the beach as a demarcater of the precarious boundary between land and the sea, as well as between nature and culture.
Resumo:
Das Lernen einer Fertigkeit durch Demonstration und anschließendes Üben wird „Modeling“ genannt. Es basiert darauf, die Diskrepanz zwischen dem Soll-Zustand (Demonstration) und dem Ist-Zustand (Üben) zu erkennen und zu beheben. Dafür ist die exakte Analyse der eigenen Fertigkeiten beim Üben unentbehrlich. Entsprechend ist auch bekannt, dass formative Evaluationen wesentlich zum erfolgreichen Lernen beitragen. Wir haben deshalb im Kurs für periphere Venenpunktion im 3. Studienjahr formatives Selbst- und Peer-Assessment eingeführt. Die Struktur des Assessment entspricht einem DOPS (dircect observation of procedural skills). DOPS stammt aus dem Arbeitsplatz-basieren Assessment und beinhaltet die Beurteilung folgender Kriterien: Vorbereitung/Nachsorge, technische Fertigkeit, Asepsis/Sicherheit, klinische Urteilsfähigkeit, Organisation/Effizienz, professionelles Verhalten, Gesamteindruck. Diese Kriterien wurden für den Unterricht konkretisiert (z.B. Vorbereitung mit Beschriftung der Röhrchen, etc.) und den Studierenden als Merkblätter ausgeteilt. Die Studierenden beurteilten ihre eigene Performance bzw. die eines Kommilitonen, gaben sich Feedback und legten individuelle Lernziele zur Verbesserung fest. Dieses Vorgehen hat den Vorteil, dass sowohl der Übende, als auch der beobachtende Kommilitone, die optimale Ausführung der jeweiligen Tätigkeit reflektieren, welches für beide eine Möglichkeit zum Lernen bietet . Bei der Evaluation des Kurses wurden die Handouts mit den Kriterien der DOPS von Teilnehmern von 9 der 10 Gruppen positiv erwähnt. Im Rahmen eines Debriefing mit den studentischen Tutoren wurde jedoch kritisch angemerkt, dass der Prozess der formativen Selbst- und Fremdevaluation den Studierenden im 3. Studienjahr nicht vertraut war. Es war für die Teilnehmer schwierig konkretes Feedback zu geben und individuelle Lernziele festzulegen. Für das kommende Jahr planen wir in Bezug auf den Kurs folgendes: Die Kriterien der korrekten Durchführung einer Fertigkeit zu formulieren wird von den Teilnehmern als hilfreich empfunden und soll deshalb beibehalten werden. Die Studierenden, die dieses Jahr an dem Kurs teilnehmen, haben bereits ein Feedbacktraining absolviert. Der Kurs kann deshalb neu an Vorkenntnisse anknüpfen. Darüber hinaus soll der Prozess der Festlegung der individuellen Lernziele in der Schulung der studentischen Tutoren des Kurses mehr Gewicht erhalten, damit die Tutoren die Teilnehmer hier gezielt unterstützen können.