Integrating GeoGebra into IWB-equipped teaching environments: Preliminary results

The aims of the project described in this paper are threefold. Firstly, we aim to examine how GeoGebra, an open-source dynamic mathematics software application, can be used successfully for mathematics teaching in Interactive Whiteboard (IWB)-equipped teaching environments. Secondly, we intend to uncover how professional development programmes could be developed and improved for the joint use of GeoGebra and IWB. Thirdly, we aspire to identify additional software features that would make GeoGebra more suitable for IWB environments. During the past year several workshops about the use of GeoGebra with IWB were offered for teachers and teacher educators in schools and conferences in Hungary. Participant feedback and comments were collected at these events and training materials have been continuously improved. This paper reports on the preliminary data analysis from the first round of the project highlighting participants ’ recommendations for improving both software features and professional development workshops

Avoiding sternotomy in repeat coronary artery bypass grafting: Feasibility, safety, and mid-term outcome of the transabdominal off-pump technique using the right gastroepiploic artery.

Item does not contain fulltextOBJECTIVES: Repeat sternotomy is associated with a substantial risk of cardiovascular injury. We evaluated the feasibility and clinical outcome of a transabdominal approach without sternotomy and without cardiopulmonary bypass in repeat coronary artery bypass grafting, using the right gastroepiploic artery to graft vessels of the inferior wall of the heart. METHODS: From July 1999 to October 2010, 22 patients presenting with only right coronary artery disease underwent reoperation using the transabdominal approach and a skeletonized gastroepiploic artery graft. In all patients but 1, a patent graft to the anterior wall was present. The mean EuroSCORE was 6.4 +/- 2.5. RESULTS: All patients had adequate surgical exposure, and no conversion to sternotomy or the use of cardiopulmonary bypass was required. There was no in-hospital mortality. Hospital morbidity included pneumothorax in 1 patient and atrial fibrillation in 2 patients. The median hospital stay was 5 days. Follow-up was complete, and the median follow-up time was 6 years. There were 2 late deaths. Four patients experienced recurrence of angina, of whom three required percutaneous coronary intervention. The estimated freedom from major cardiovascular and cerebrovascular events rate was 70.2% at 6 years. Fourteen patients underwent an exercise stress test at a median interval of 2 years, with all showing no signs of myocardial ischemia. CONCLUSIONS: Transabdominal off-pump coronary artery bypass grafting using the right gastroepiploic artery is a safe and effective procedure with low in-hospital mortality and morbidity and favorable mid-term outcome. In redo operations, this technique excludes the risk of cardiovascular injury.1 juli 201

Reoperation for right ventricular outflow tract obstruction after arterial switch operation for transposition of the great arteries and aortic arch obstruction

Cardiolog

The pathology of fresh and cryopreserved homograft heart valves: An analysis of forty explanted homograft valves

Objective: Tissue degeneration reduces the durability of aortic and pulmonary homograft heart valves. Homograft valves can evoke cellular and humoral immune responses that might be detrimental to the valve tissue. Analyzing explanted homograft valves helps in understanding the different factors that eventually lead to tissue degeneration. Methods: A total of 40 homografts was acquired from patients whose grafts had been explanted because of stenosis (n = 22). insufficiency (n = 8), paravalvular leakage (n = 4), other technical problems (n = 4), noncardiac death (n = 1), and stenosis with endocarditis (n = 1). The period of implantation varied from 14 days to 16 years (median, 4 years). Cryopreserved valves (n = 31) were, in the majority, derived from beating-heart donors, whereas the fresh valves were sterilized with antibiotics and stored at 4°C for an average of 32 days. Four unimplanted cryopreserved valves, 1 native aortic valve, and 1 native pulmonary valve were used as references. Analysis included macroscopy, light microscopy with routine hematoxylin and eosin staining (cellularity and tissue structure), and immunohistochemical studies to allow identification of macrophages (CD68) and T lymphocytes (CD3), endothelial cells, leukocyte adhesion molecules (CD54, CD106, and CD62E), and immunoglobulin (IgG) and complement factor (C3) depositions. In situ hybridization for the Y chromosome was performed in 10 cases, with host-donor sex mismatch, to distinguish between host and donor cells. The outcomes of histology and immunohistochemistry were related to clinical factors, such as implantation time and reason for explantation. Results: In the first year after implantation, a strong reduction in cellularity of the valve tissue was observed, with almost acellular tissues after 1 year. Trilaminar tissue architecture disappeared with the same speed, whereas endothelial cells were almost absent in all explants. Macrophages and T lymphocytes were encountered in 85% and 78% of the leaflets, respectively. Expression of leukocyte adhesion molecules was low in almost all grafts, and IgG and C3 depositions were not increased. Valve tissue cellularity consisted mainly of ingrown host cells when the implantation time exceeded 1 year. Conclusions: During the first year of implantation, homograft valves rapidly lose their cellular components and normal tissue architecture. A low-grade inflammatory response was observed, but no convincing evidence of immune-mediated injury was found

The pathology of fresh and cryopreserved homograft heart valves: An analysis of forty explanted homograft valves

Objective: Tissue degeneration reduces the durability of aortic and pulmonary homograft heart valves. Homograft valves can evoke cellular and humoral immune responses that might be detrimental to the valve tissue. Analyzing explanted homograft valves helps in understanding the different factors that eventually lead to tissue degeneration. Methods: A total of 40 homografts was acquired from patients whose grafts had been explanted because of stenosis (n = 22). insufficiency (n = 8), paravalvular leakage (n = 4), other technical problems (n = 4), noncardiac death (n = 1), and stenosis with endocarditis (n = 1). The period of implantation varied from 14 days to 16 years (median, 4 years). Cryopreserved valves (n = 31) were, in the majority, derived from beating-heart donors, whereas the fresh valves were sterilized with antibiotics and stored at 4°C for an average of 32 days. Four unimplanted cryopreserved valves, 1 native aortic valve, and 1 native pulmonary valve were used as references. Analysis included macroscopy, light microscopy with routine hematoxylin and eosin staining (cellularity and tissue structure), and immunohistochemical studies to allow identification of macrophages (CD68) and T lymphocytes (CD3), endothelial cells, leukocyte adhesion molecules (CD54, CD106, and CD62E), and immunoglobulin (IgG) and complement factor (C3) depositions. In situ hybridization for the Y chromosome was performed in 10 cases, with host-donor sex mismatch, to distinguish between host and donor cells. The outcomes of histology and immunohistochemistry were related to clinical factors, such as implantation time and reason for explantation. Results: In the first year after implantation, a strong reduction in cellularity of the valve tissue was observed, with almost acellular tissues after 1 year. Trilaminar tissue architecture disappeared with the same speed, whereas endothelial cells were almost absent in all explants. Macrophages and T lymphocytes were encountered in 85% and 78% of the leaflets, respectively. Expression of leukocyte adhesion molecules was low in almost all grafts, and IgG and C3 depositions were not increased. Valve tissue cellularity consisted mainly of ingrown host cells when the implantation time exceeded 1 year. Conclusions: During the first year of implantation, homograft valves rapidly lose their cellular components and normal tissue architecture. A low-grade inflammatory response was observed, but no convincing evidence of immune-mediated injury was found

Revealing Unforeseen Diagnostic Image Features With Deep Learning by Detecting Cardiovascular Diseases From Apical 4-Chamber Ultrasounds

BACKGROUND: With the increase of highly portable, wireless, and low-cost ultrasound devices and automatic ultrasound ac-quisition techniques, an automated interpretation method requiring only a limited set of views as input could make preliminary cardiovascular disease diagnoses more accessible. In this study, we developed a deep learning method for automated detection of impaired left ventricular (LV) function and aortic valve (AV) regurgitation from apical 4-chamber ultrasound cineloops and investigated which anatomical structures or temporal frames provided the most relevant information for the deep learning model to enable disease classification. METHODS AND RESULTS: Apical 4-chamber ultrasounds were extracted from 3554 echocardiograms of patients with impaired LV function (n=928), AV regurgitation (n=738), or no significant abnormalities (n=1888). Two convolutional neural networks were trained separately to classify the respective disease cases against normal cases. The overall classification accuracy of the impaired LV function detection model was 86%, and that of the AV regurgitation detection model was 83%. Feature importance analyses demonstrated that the LV myocardium and mitral valve were important for detecting impaired LV function, whereas the tip of the mitral valve anterior leaflet, during opening, was considered important for detecting AV regurgitation. CONCLUSIONS: The proposed method demonstrated the feasibility of a 3-dimensional convolutional neural network approach in detection of impaired LV function and AV regurgitation using apical 4-chamber ultrasound cineloops. The current study shows that deep learning methods can exploit large training data to detect diseases in a different way than conventionally agreed on methods, and potentially reveal unforeseen diagnostic image features

A 45-year experience with the Fontan procedure: tachyarrhythmia, an important sign for adverse outcome

OBJECTIVES: This study aims to evaluate our 45-year experience with the Fontan procedure and to identify risk factors for late mortality and morbidity. METHODS: Demographic, preoperative, perioperative and postoperative characteristics were retrospectively collected for all patients who underwent a Fontan procedure in a single centre between 1972 and 2016. RESULTS: The study included 277 Fontan procedures (44 atriopulmonary connections, 28 Fontan-Björk, 42 lateral tunnels and 163 extracardiac conduits). Early failure occurred in 17 patients (6.1%). Median follow-up of the study cohort was 11.9 years (Q1-Q3 7.6-17.5). Longest survival estimates were 31% [95% confidence intervals (CI) 18-44%] at 35 years for atriopulmonary connection/Björk, 87% (95% CI 63-96%) at 20 years for lateral tunnel and 99% (95% CI 96-100%) at 15 years for extracardiac conduit. Estimated freedom from Fontan failure (death, heart transplant, take-down, protein-losing enteropathy, New York Heart Association III-IV) at 15 years was 65% (95% CI 52-76%) for atriopulmonary connection/Björk, 90% (95% CI 73-97%) for lateral tunnel and 90% (95% CI 82-94%) for extracardiac conduit. The development of tachyarrhythmia was an important predictor of Fontan failure [hazard ratio (HR) 2.6, 95% CI 1.2-5.8; P = 0.017], thromboembolic/neurological events (HR 3.6, 95% CI 1.4-9.4; P = 0.008) and pacemaker for sinus node dysfunction (HR 3.7, 95% CI 1.4-9.6; P = 0.008). Prolonged pleural effusion (>21 days) increased the risk of experiencing protein-losing enteropathy (HR 4.7, 95% CI 2.0-11.1; P < 0.001). CONCLUSIONS: With modern techniques, survival and freedom from Fontan failure are good. However, Fontan patients remain subject to general attrition. Tachyarrhythmia is an important sign for an adverse outcome. Prevention and early treatment of tachyarrhythmia may, therefore, be paramount in improving the long-term outcome