A deep vein thrombosis caused by 20209C>T mutation in homozygosis of the prothrombin gene in a Caucasian patient

Introduction:

Additional nucleotide substitutions in the 3′-untranslated region of prothrombin gene could explain some thrombotic events and also adverse pregnancy outcomes. We describe the first case of a homozygous 20209C>T mutation as the cause of deep vein thrombosis in a Spanish patient.

Case and methods:

The 56-year-old male patient with a partial tear of the Achilles tendon developed calf (tibial) deep vein thrombosis after immobilization and was treated with an anticoagulant. To determine if the deep vein thrombosis was of genetic origin, a peripheral blood DNA sample was analysed for the presence of the three most frequent mutations associated with thrombotic events: factor V Leiden (1691G>A), prothrombin (20210G>A) and methylene tetrahydrofolate reductase (677C>T). The presence or absence of the normal allele of prothrombin could not be determined using the PTH-FV-MTHFR StripAssay (Vienna Lab).

Results:

Comprehensive analysis showed that the patient had a variant interfering with the polymerase chain reaction product, we sequenced the entire prothrombin gene and found that the patient had a homozygous C>T mutation at position 20209; this interfered with the polymerase chain reaction product, which needs a C at this position to be able to bind to the wild-type probe present in the test strip.

Conclusion:

The homozygous 20209C>T mutation and the presence of the mutation 677C>T in heterozygosity explained the patient’s deep vein thrombosis because the combination of mutations would increase the risk of thrombosis. Suitable genetic counselling should be provided to the patient and first-degree relatives as it important to detect prothrombin gene variants that could increase risk for thrombotic events.     

Examination of the role of transient receptor potential vanilloid type 4 in endothelial responses to shear forces

Shear stress is the major mechanical force applied on vascular endothelial cells by blood flow, and is a crucial factor in normal vascular physiology and in the development of some vascular pathologies. The exact mechanisms of cellular mechano-transduction in mammalian cells and tissues have not yet been elucidated, but it is known that mechanically sensitive receptors and ion channels play a crucial role. This paper describes the use of a novel and efficient microfluidic device to study mechanically-sensitive receptors and ion channels in vitro, which has three independent channels from which recordings can be made and has a small surface area such that fewer cells are required than for conventional flow chambers. The contoured channels of the device enabled examination of a range of shear stresses in one field of view, which is not possible with parallel plate flow chambers and other previously used devices, where one level of flow-induced shear stress is produced per fixed flow-rate. We exposed bovine aortic endothelial cells to different levels of shear stress, and measured the resulting change in intracellular calcium levels ([Ca²⁺]_i) using the fluorescent calcium sensitive dye Fluo-4AM. Shear stress caused an elevation of [Ca²⁺]_i that was proportional to the level of shear experienced. The response was temperature dependant such that at lower temperatures more shear stress was required to elicit a given level of calcium signal and the magnitude of influx was reduced. We demonstrated that shear stress-induced elevations in [Ca²⁺]_i are largely due to calcium influx through the transient receptor potential vanilloid type 4 ion channel.     

Growth influences biomechanical profile of talented swimmers during the summer break

This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011–2012 season (pre-test) and 10 weeks later at the beginning of the 2012–2013 season (post-test). Height, arm span, hand surface area, and foot surface area were collected as anthropometric parameters, while stroke frequency, stroke length, stroke index, propelling efficiency, active drag, and active drag coefficient were considered as biomechanical variables. The mean swimming velocity during an all-out 25 m front crawl effort was used as the performance outcome. After the 10-week break, the swimmers were taller with an increased arm span, hand, and foot areas. Increases in stroke length, stroke index, propelling efficiency, and performance were also observed. Conversely, the stroke frequency, active drag, and drag coefficient remained unchanged. When controlling the effect of growth, no significant variation was determined on the biomechanical variables. The performance presented high associations with biomechanical and anthropometric parameters at pre-test and post-test, respectively. The results show that young talented swimmers still present biomechanical improvements after a 10-week break, which are mainly explained by their normal growth.     

Inclusive Pedagogy in Light of Social Justice. Special Educational Rights and Inclusive Classrooms: on whose terms? A Field Study in Stockholm Suburbs

The question of inclusive education is not straightforward. Despite all its good intentions, inclusive education, in practice faces numerous challenges today. This study analyses these challenges in the Swedish special education context. The author explores special educators’ experiences, possibilities and challenges when applying inclusive education. Findings reveal positive attitudes to the concept of inclusive classrooms. Nevertheless, teachers face more than a few grey areas that need to be put in place in order to achieve socially and cognitively inclusive classrooms.     

Support teachers' beliefs about the academic achievement of students with special educational needs

José Castro Silva, lecturer in sciences of education, and José Morgado, assistant professor, both work at the Instituto Superior de Psicologica Aplicada in Lisboa, Portugal. In this article, they describe their study of support teachers' beliefs about the academic achievement of school students with special educational needs. The 'support teachers' who were the subject of this study work in mainstream schools where the majority of pupils with special educational needs are educated in mainstream classes run by 'general teachers'. The work of the support teachers is supervised and supported by 'special education team co-ordinators'. The study reported here set out to elicit the support teachers' beliefs about the factors that contribute to success at school for pupils with special educational needs. Results suggest that the support teachers consider that factors including 'school climate', 'curriculum design' and 'teaching approach' contribute significantly to achievements among these pupils. On the other hand, analysis reveals that the support teachers attribute difficulties and lack of achievement significantly to 'out-of-school' contextual variables. These findings are related to a detailed review of the literature and the authors discuss the implications for policy, practice and professional development.     

Socio-cultural variation in reading comprehension development among fifth graders in Peru

In this study, the socio-cultural variation in reading comprehension development was examined in 331 fifth graders from schools in Lima, Peru. Reading comprehension was measured using an adaptation of the PIRLS Reading Literacy test. The fifth graders?? reading comprehension results, measured over the course of fifth grade, were related to the development of word decoding, vocabulary, and motivation for reading. Children??s development in these domains was related to their gender, intellectual maturity, home literacy climate, and socio-economic status. Structural Equation Modelling showed that the development of reading comprehension was influenced by the children??s ability to decode words, their vocabulary, and reading motivation. Furthermore, gender and intellectual maturity as well as children??s home literacy climate and socio-economic status appeared to substantially predict reading comprehension development, directly or indirectly. More than half of the variance in reading comprehension by the end of the fifth grade could be explained based on these predictor variables.     

Why Implementing History and Philosophy in School Science Education is a Challenge: An Analysis of Obstacles

Teaching and learning with history and philosophy of science (HPS) has been, and continues to be, supported by science educators. While science education standards documents in many countries also stress the importance of teaching and learning with HPS, the approach still suffers from ineffective implementation in school science teaching. In order to better understand this problem, an analysis of the obstacles of implementing HPS into classrooms was undertaken. The obstacles taken into account were structured in four groups: 1. culture of teaching physics, 2. teachers?? skills, epistemological and didactical attitudes and beliefs, 3. institutional framework of science teaching, and 4. textbooks as fundamental didactical support. Implications for more effective implementation of HPS are presented, taking the social nature of educational systems into account.     

The impact of a peer-tutoring program on quality standards in higher education

The purposes of this study were, on one had, to determine the impact of a peer tutoring program on preventing academic failure and dropouts among first-year students (N = 100), from Civil Engineering, Economics, Pharmacy, and Chemical Engineering careers; while, on the other hand, to identify the potential benefits of such tutoring program on the cognitive and metacognitive learning strategies and social skills of student mentors in their last year of studies or already in a postgraduate program (N = 41) at the University of Granada (Spain). After building and selecting the measurement instruments necessary to gather demographic and academic relevant information on both samples, and assigning first-year students to either an experimental or control group, the intervention consisted of ten 90-min tutoring sessions during the first semester lead by student tutors who, in turn, had undergone four 3-h training sessions on tutoring contents like planning and time management, cognitive and metacognitive learning strategies, motivational strategies and the use of materials designed ad hoc for this program. The results show differences in favour of the treatment group on grade point average, performance rate, success rate and learning strategies and, also, statistically significant pre-post differences for the tutors on learning strategies and social skills.