301 research outputs found

    Lymphoid Microenvironments in the Thymus and Lymph Node

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    The three-dimensional architecture of the thymus and mesenteric lymph node reveals several different stromal cell types important in the development and function of T cells. In the thymic cortex, T cells proliferate and differentiate in a meshwork of epithelial-reticular cells. They then migrate towards the medulla where they may interact with interdigitating cells. T cells migrate from the thymus through perivascular spaces, surrounding large vessels at the cortico-medullary boundary. In this area also large thymic cystic cavities are found, their function remains at present unclear. Mature selected T cells leave the thymus most probably by the venous bloodstream, to enter peripheral lymph nodes. Upon entering the lymph node they cross the wall of high endothelial venules. On the other hand, lymph enters the node by afferent lymphatics draining into various types of sinuses. Here, macrophages are strategically located to phagocytose and process antigen. These cells then expose antigen to T cells and B cells within the lymph node parenchyma, thus creating a microenvironment for the onset of an immune response. The various microenvironments important in T cell development and T cell function are shown in this paper using scanning electron microscopy as a dissecting tool. We discuss our morphological findings in the light of recent data on the physiology of T cell differentiation and function

    Inhibition of proliferation and differentiation during early T cell development by anti-transferrin receptor antibody

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    Proliferating cells require iron and, therefore, express the transferrin receptor (CD71) that mediates cellular iron uptake. Cycling thymocytes, which have the CD4−8−3−, CD4−8+3−, or CD4+8+3− phenotypes, also express CD71. The importance of CD71-mediated iron uptake for proliferation and maturation of thymocytes was studied using fetal thymus organ cultures at day 14 of gestation and treating them for 7 days with a CD71 monoclonal antibody (mAb). The intracellular iron deficiency caused by this treatment, inhibits both proliferation and maturation of the thymocytes. Cell recovery was reduced by 60%, but cells still expanded tenfold during the culture. Remarkably, the final maturation of αβ T cells was completely blocked as no thymocytes with low or high CD3/αβTcR expression developed. Moreover, only few cells reached the CD4+8+3− stage of T cell development. CD4−8−3− thymocytes, however, as well as its CD44−25+ subset developed in normal numbers, suggesting that CD44−25+ CD4−8−3− cells, or their immediate progeny, were most vulnerable to CD71 mAb treatment. The development of γδ T cells, which also express CD71, was not affected in these cultures. This suggests that γδ T cells are either less iron-dependent or possess alternative iron-uptake mechanisms. Thus, our observation

    Measuring students' self-regulated learning in professional education: bridging the gap between event and aptitude measurements.

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    Self-regulated learning has benefits for students' academic performance in school, but also for expertise development during their professional career. This study examined the validity of an instrument to measure student teachers' regulation of their learning to teach across multiple and different kinds of learning events in the context of a postgraduate professional teacher education programme. Based on an analysis of the literature, we developed a log with structured questions that could be used as a multiple-event instrument to determine the quality of student teachers' regulation of learning by combining data from multiple learning experiences. The findings showed that this structured version of the instrument measured student teachers' regulation of their learning in a valid and reliable way. Furthermore, with the aid of the Structured Learning Report individual differences in student teachers' regulation of learning could be discerned. Together the findings indicate that a multiple-event instrument can be used to measure regulation of learning in multiple contexts for various learning experiences at the same time, without the necessity of relying on students' ability to rate themselves across all these different experiences. In this way, this instrument can make an important contribution to bridging the gap between two dominant approaches to measure SRL, the traditional aptitude and event measurement approach

    Ковчег Ноя: рух матерії у Сонячній системі та на ядерних рівнях Землі

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    У Стародавньому світі пророку Мойсею було відкрито таємницю створення світу. Як науковий геній свого часу, Мойсей зашифрував у алегоричну форму в родоводі Адама і Потопі прикладну науку про будову ядра Землі, Сонячної системи і рухи космічної водневої і сонячної вуглецевої матерій (енергій) крізь Землю.В Древнем мире пророку Моисею была открыта тайна создания мира. Как научный гений своего времени Моисей зашифровал в форму аллегории в родословной Адама и Потопе прикладную науку о строении ядра Земли, Солнечной системы и движениях космической водородной и солнечной углеродной материи (энергии) сквозь Землю.In the Ancient history the mystery of the Creation of the world was revealed to the Prophet Moses. As a scientific genius of that époque Moses codified in allegoric way in the genealogy of Adam and The Flood the applied science on the structure of the Earth core, of the Solar System and motion of cosmic hydrogenous and solar carbonic substance (energy) through the Earth

    Outcome of intracranial bleeding managed with prothrombin complex concentrate in patients on direct factor Xa inhibitors or vitamin K antagonists

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    Intracranial hemorrhage (ICH) is the most feared complication of anticoagulation with a high mortality and morbidity. Before registration of a specific reversal agent for factor Xa inhibitors (FXa-I), international guidelines recommended prothrombin complex concentrate (PCC), which also is the specific reversal agent for vitamin K antagonists (VKA). In two contemporary cohorts, we compared clinical outcomes between patients with FXa-I and VKA related ICH treated with PCC between 2014 and 2018. Primary outcome was effective hemostasis after 24 h, according to the International Society of Thrombosis and Hemostasis definition. Safety outcomes were defined as venous and arterial thromboembolic complications and death within 30 days. Thirty-six patients with FXa-I-ICH and 39 patients with VKA-ICH were available for analysis. Baseline characteristics were comparable between both groups, except for time from start of symptoms to presentation at the hospital. In the FXa-I-ICH cohort, 24 (73%) patients achieved effective hemostasis compared to 23 (62%) patients in the VKA-ICH cohort (crude odds ratio [OR] 1.62 [95%CI 0.59–4.48], adjusted OR 1.45 [95%CI 0.44–4.83]). Eight (24%) patients with FXa-I-ICH deceased compared to 17 (45%) patients with VKA-ICH (crude OR 0.38 [95%CI 0.14–1.24], adjusted OR 0.41 [95%CI 0.12–1.24]). In this observational cohort study, the outcome of ICH managed with PCC was similar in patients with FXa-I-ICH and in patients with VKA-ICH

    Interpersonal adaptation in teacher-student interaction

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    Teacher-student relationships play a crucial role in the quality of teaching and learning. Daily interpersonal interactions in classrooms are the building blocks of teacher-student relationships. With the aim to add to insights on teaching and learning, we specifically explored interpersonal adaptation in daily interactions. Adaptation, i.e., how people respond to each other's actions and reactions, is a defining characteristic of interactions. We studied 35 classrooms in secondary education. Although the degree and nature of interpersonal adaptation was in general consistent with interpersonal theory, degree of adaptation varied considerably between classrooms. In classrooms with a more preferred teacher-student relationship, behaviour of teachers and the adaptation to the behaviour of their students was more in accordance with professional standards, compared to classrooms with a less preferred relationship. Conceptualizations and results of the present study contribute to theory on teacher-student interaction, as well as the practice of teacher professional development (e.g., video coaching).Teaching and Teacher Learning (ICLON

    Successful oxytocin-assisted nipple aspiration in women at increased risk for breast cancer

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    The high rate of interval malignancies urges for new screening methods for women at high risk for breast cancer. Nipple aspiration provides direct access to the breast tissue and its DNA, and therefore is a likely candidate, but clinical applications have been limited by the failure to obtain nipple aspiration fluid from most women. We performed oxytocin-assisted nipple aspiration in 90 women at increased risk for breast cancer based on family history or genetic test results (n = 63) and/or previous breast cancer (n = 34). Nipple fluid was obtained from 81/90 women (90%) and bilaterally in 77%. Mean discomfort rating was 0.6 (on a 0–10 scale), which was significantly lower than for mammography or MRI. These findings suggest that a new tool for biomarker detection in oxytocin-assisted nipple fluid of women at high risk for breast cancer is at hand

    Survival in Norwegian BRCA1 mutation carriers with breast cancer

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    Several studies of survival in women with BRCA1 mutations have shown either reduced survival or no difference compared to controls. Programmes for early detection and treatment of inherited breast cancer, have failed to demonstrate a significant improvement in survival in BRCA1 mutation carriers
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