Construction of a two-parameter empirical model of left ventricle wall motion using cardiac tagged magnetic resonance imaging data

Abstract Background A one-parameter model was previously proposed to characterize the short axis motion of the LV wall at the mid-ventricle level. The single parameter of this model was associated with the radial contraction of myocardium, but more comprehensive model was needed to account for the rotation at the apex and base levels. The current study developed such model and demonstrated its merits and limitations with examples. Materials and methods The hearts of five healthy individuals were visualized using cardiac tagged magnetic resonance imaging (tMRI) covering the contraction and relaxation phases. Based on the characteristics of the overall dynamics of the LV wall, its motion was represented by a combination of two components - radial and rotational. Each component was represented by a transformation matrix with a time-dependent variable α or β. Image preprocessing step and model fitting algorithm were described and applied to estimate the temporal profiles of α and β within a cardiac cycle at the apex, mid-ventricle and base levels. During this process, the tagged lines of the acquired images served as landmark reference for comparing against the model prediction of the motion. Qualitative and quantitative analyses were performed for testing the performance of the model and thus its validation. Results The α and β estimates exhibited similarities in values and temporal trends once they were scaled by the radius of the epicardium (r epi )and plotted against the time scaled by the period of the cardiac cycle (T cardiac ) of each heart measured during the data acquisition. α/r epi peaked at about Δt/T cardiac =0.4 and with values 0.34, 0.4 and 0.3 for the apex, mid-ventricle and base level, respectively. β/r epi similarly maximized in amplitude at about Δt/T cardiac =0.4, but read 0.2 for the apex and - 0.08 for the base level. The difference indicated that the apex twisted more than the base. Conclusion It is feasible to empirically model the spatial and temporal evolution of the LV wall motion using a two-parameter formulation in conjunction with tMRI-based visualization of the LV wall in the transverse planes of the apex, mid-ventricle and base. In healthy hearts, the analytical model will potentially allow deriving biomechanical entities, such as strain, strain rate or torsion, which are typically used as diagnostic, prognostic or predictive markers of cardiovascular diseases including diabetes.Peer Reviewe

A model-based time-reversal of left ventricular motion improves cardiac motion analysis using tagged MRI data

<p>Abstract</p> <p>Background</p> <p>Myocardial motion is an important observable for the assessment of heart condition. Accurate estimates of ventricular (LV) wall motion are required for quantifying myocardial deformation and assessing local tissue function and viability. Harmonic Phase (HARP) analysis was developed for measuring regional LV motion using tagged magnetic resonance imaging (tMRI) data. With current computer-aided postprocessing tools including HARP analysis, large motions experienced by myocardial tissue are, however, often intractable to measure. This paper addresses this issue and provides a solution to make such measurements possible.</p> <p>Methods</p> <p>To improve the estimation performance of large cardiac motions while analyzing tMRI data sets, we propose a two-step solution. The first step involves constructing a model to describe average systolic motion of the LV wall within a subject group. The second step involves time-reversal of the model applied as a spatial coordinate transformation to digitally relax the contracted LV wall in the experimental data of a single subject to the beginning of systole. Cardiac tMRI scans were performed on four healthy rats and used for developing the forward LV model. Algorithms were implemented for preprocessing the tMRI data, optimizing the model parameters and performing the HARP analysis. Slices from the midventricular level were then analyzed for all systolic phases.</p> <p>Results</p> <p>The time-reversal operation derived from the LV model accounted for the bulk portion of the myocardial motion, which was the average motion experienced within the overall subject population. In analyzing the individual tMRI data sets, removing this average with the time-reversal operation left small magnitude residual motion unique to the case. This remaining residual portion of the motion was estimated robustly using the HARP analysis.</p> <p>Conclusion</p> <p>Utilizing a combination of the forward LV model and its time reversal improves the performance of motion estimation in evaluating the cardiac function.</p

Construction of a two-parameter empirical model of left ventricle wall motion using cardiac tagged magnetic resonance imaging data

Background A one-parameter model was previously proposed to characterize the short axis motion of the LV wall at the mid-ventricle level. The single parameter of this model was associated with the radial contraction of myocardium, but more comprehensive model was needed to account for the rotation at the apex and base levels. The current study developed such model and demonstrated its merits and limitations with examples. Materials and methods The hearts of five healthy individuals were visualized using cardiac tagged magnetic resonance imaging (tMRI) covering the contraction and relaxation phases. Based on the characteristics of the overall dynamics of the LV wall, its motion was represented by a combination of two components - radial and rotational. Each component was represented by a transformation matrix with a time-dependent variable α or β. Image preprocessing step and model fitting algorithm were described and applied to estimate the temporal profiles of α and β within a cardiac cycle at the apex, mid-ventricle and base levels. During this process, the tagged lines of the acquired images served as landmark reference for comparing against the model prediction of the motion. Qualitative and quantitative analyses were performed for testing the performance of the model and thus its validation. Results The α and β estimates exhibited similarities in values and temporal trends once they were scaled by the radius of the epicardium (repi)and plotted against the time scaled by the period of the cardiac cycle (Tcardiac) of each heart measured during the data acquisition. α/repi peaked at about Δt/Tcardiac=0.4 and with values 0.34, 0.4 and 0.3 for the apex, mid-ventricle and base level, respectively. β/repi similarly maximized in amplitude at about Δt/Tcardiac=0.4, but read 0.2 for the apex and - 0.08 for the base level. The difference indicated that the apex twisted more than the base. Conclusion It is feasible to empirically model the spatial and temporal evolution of the LV wall motion using a two-parameter formulation in conjunction with tMRI-based visualization of the LV wall in the transverse planes of the apex, mid-ventricle and base. In healthy hearts, the analytical model will potentially allow deriving biomechanical entities, such as strain, strain rate or torsion, which are typically used as diagnostic, prognostic or predictive markers of cardiovascular diseases including diabetes

Intracellular Ca2+ regulating proteins in vascular smooth muscle cells are altered with type 1 diabetes due to the direct effects of hyperglycemia

<p>Abstract</p> <p>Background</p> <p>Diminished calcium (Ca²⁺) transients in response to physiological agonists have been reported in vascular smooth muscle cells (VSMCs) from diabetic animals. However, the mechanism responsible was unclear.</p> <p>Methodology/Principal Findings</p> <p>VSMCs from autoimmune type 1 Diabetes Resistant Bio-Breeding (DR-BB) rats and streptozotocin-induced rats were examined for levels and distribution of inositol trisphosphate receptors (IP₃R) and the SR Ca²⁺pumps (SERCA 2 and 3). Generally, a decrease in IP₃R levels and dramatic increase in ryanodine receptor (RyR) levels were noted in the aortic samples from diabetic animals. Redistribution of the specific IP₃R subtypes was dependent on the rat model. SERCA 2 was redistributed to a peri-nuclear pattern that was more prominent in the DR-BB diabetic rat aorta than the STZ diabetic rat. The free intracellular Ca²⁺in freshly dispersed VSMCs from control and diabetic animals was monitored using ratiometric Ca²⁺sensitive fluorophores viewed by confocal microscopy. In control VSMCs, basal fluorescence levels were significantly higher in the nucleus relative to the cytoplasm, while in diabetic VSMCs they were essentially the same. Vasopressin induced a predictable increase in free intracellular Ca²⁺in the VSMCs from control rats with a prolonged and significantly blunted response in the diabetic VSMCs. A slow rise in free intracellular Ca²⁺in response to thapsigargin, a specific blocker of SERCA was seen in the control VSMCs but was significantly delayed and prolonged in cells from diabetic rats. To determine whether the changes were due to the direct effects of hyperglycemica, experiments were repeated using cultured rat aortic smooth muscle cells (A7r5) grown in hyperglycemic and control conditions. In general, they demonstrated the same changes in protein levels and distribution as well as the blunted Ca²⁺responses to vasopressin and thapsigargin as noted in the cells from diabetic animals.</p> <p>Conclusions/Significance</p> <p>This work demonstrates that the previously-reported reduced Ca²⁺signaling in VSMCs from diabetic animals is related to decreases and/or redistribution in the IP₃R Ca²⁺channels and SERCA proteins. These changes can be duplicated in culture with high glucose levels.</p

Desenvolvimento de conteúdos de programas educativos de formação complementar para composição de professores na organização de serviços educativos de formação com deficiência

Guided by the results of the experimental work, the authors came to the conclusion that the use of the electronic educational and methodical complex in mathematics on the basis of modular qualification training technology is essential. The current stage in the development of educational systems is characterized by the emergence and practical introduction of inclusive education for children with disabilities in general education organizations. Inclusion in the educational process of children with disabilities is dictated not only by modern normative documents, but also by the social need for inclusive education. One of the conditions for the preparation of children with disabilities in the educational environment is the quality and special training of teachers who must possess certain knowledge and skills to work with children with disabilities. Therefore, this study aimed to address the problem of training teachers in additional vocational education to work with children with disabilities. We conducted a training experiment, in which the professors of the university participated. The purpose of the pilot work was to improve the quality of teacher training in additional professional education to create an inclusive educational environment in the university. The legislative concepts of the Russian Federation are justified. One of the priority directions for the education of children with mental retardation (intellectual disabilities) along with general education is to give them a real opportunity to obtain a profession. The requirements for the results of the development of the complementary education program for children reflect the set of individual, public and state needs. The article gives an example of the developed program of additional professional education for the teaching staff and gives an example of the subject matter of the taught modules. Applying the teacher's professional skills training technology in additional education, additional education courses have been developed for the teaching staff of the university. An example is given of the opening of a resource center at the K. Minin University, which allows solving the main tasks of vocational training for children with disabilities.Guiados por los resultados del trabajo experimental, los autores llegaron a la conclusión de que el uso del complejo educativo y metódico electrónico en matemáticas sobre la base de la tecnología de capacitación de calificación modular es esencial. La etapa actual en el desarrollo de los sistemas educativos se caracteriza por el surgimiento y la introducción en la práctica de la educación inclusiva de los niños con discapacidades en las organizaciones de educación general. La inclusión en el proceso educativo de los niños con discapacidades está dictada no solo por los documentos normativos modernos, sino también por la necesidad social de una educación inclusiva. Una de las condiciones para la preparación de niños con discapacidades en el entorno educativo es la calidad y la capacitación especial de los maestros que deben poseer ciertos conocimientos y habilidades para trabajar con niños con discapacidades. Por lo tanto, este estudio tuvo como objetivo abordar el problema de la capacitación de maestros en educación vocacional adicional para trabajar con niños discapacitados. Realizamos un experimento formativo, en el que participaron los profesores de la universidad. El propósito del trabajo piloto fue mejorar la calidad de la capacitación de los maestros en la educación profesional adicional para crear un ambiente educativo inclusivo en la universidad. Los conceptos a nivel legislativo de la Federación de Rusia están justificados. Una de las direcciones prioritarias para la educación de los niños con retraso mental (discapacidades intelectuales) junto con la educación general es brindarles una oportunidad real de obtener una profesión. Los requisitos para los resultados del desarrollo del programa de educación complementaria para niños reflejan el conjunto de necesidades individuales, públicas y estatales. El artículo da un ejemplo del programa desarrollado de educación profesional adicional para el personal docente y se da un ejemplo de la materia de los módulos enseñados. Aplicando la tecnología de formación de competencias profesionales del docente en la educación adicional, se han desarrollado cursos de educación adicionales para el personal docente de la universidad. Se da un ejemplo de la apertura de un centro de recursos en la Universidad K. Minin, que permite resolver las tareas principales de la formación profesional para niños con discapacidades.Guiados pelos resultados do trabalho experimental, os autores chegaram à conclusão de que o uso do complexo educacional e metódico eletrônico em matemática com base na tecnologia de treinamento modular de qualificação é essencial. O estágio atual no desenvolvimento de sistemas educacionais é caracterizado pelo surgimento e introdução prática da educação inclusiva para crianças com deficiência em organizações de educação geral. A inclusão no processo educacional das crianças com deficiência é ditada não apenas pelos documentos normativos modernos, mas também pela necessidade social de educação inclusiva. Uma das condições para a preparação de crianças com deficiência no ambiente educacional é a qualidade e treinamento especial de professores que devem possuir certos conhecimentos e habilidades para trabalhar com crianças com deficiência. Portanto, este estudo teve como objetivo abordar o problema da formação de professores em educação profissional adicional para trabalhar com crianças com deficiência. Realizamos um experimento de treinamento, no qual participaram os professores da universidade. O objetivo do trabalho piloto foi melhorar a qualidade da formação de professores em educação profissional adicional para criar um ambiente educacional inclusivo na universidade. Os conceitos legislativos da Federação Russa são justificados. Uma das direções prioritárias para a educação de crianças com retardo mental (deficiência intelectual), juntamente com a educação geral, é dar-lhes uma oportunidade real de obter uma profissão. Os requisitos para os resultados do desenvolvimento do programa de educação complementar para crianças refletem o conjunto de necessidades individuais, públicas e estatais. O artigo dá um exemplo do programa desenvolvido de formação profissional adicional para o corpo docente e dá um exemplo do assunto dos módulos ensinados. Aplicando a tecnologia de treinamento de habilidades profissionais do professor em educação adicional, foram desenvolvidos cursos de educação adicionais para o corpo docente da universidade. Um exemplo é dado da abertura de um centro de recursos na Universidade K. Minin, que permite resolver as principais tarefas de formação profissional para crianças com deficiência

Modern technologies in working with gifted students

Intellectual potential acts as a driving force of social and economic development of the modern state. In a high-tech society, there is a significant increase in interest in identifying and implementing the intellectual abilities of young people. The purpose of the article is to review the experience of using modern educational technologies in working with gifted students. The paper explores the implementation of innovative technologies, including games, projects, and collaborative learning technologies. The use of project and game technologies allows to develop the creative potential of students, to form an experience of research and creative activity, to activate cognitive interest by combining theory and practice. Modern educational technologies expand the opportunities for the formation and development of children's giftedness. Giftedness is a high level of development of any abilities. They are a special resource that forms the basis of the country's competitiveness and potential, which is updated as socially significant in the context of the analysis of fundamental documents in the field of education. Educational technologies allow not only to have a purposeful educational impact on students but also to create a variable, enriched, individualized educational environment that promotes the development of independence and self-learning ability

Использование учебных видео-материалов в образовательном процессе высшего учебного заведения

This article is devoted to the creation and use of educational video clips in higher educational institutions. This article analyzes the results of studies on the impact of video content on listeners, which showed a large degree of positive impact, presents a theoretical analysis of the basics of developing video materials. The purpose of the article is to create a technology for developing instructional videos in a higher educational institution. The authors presented the experience of implementing video materials in the classroom on pedagogical disciplines. The stages of developing video materials were proposed, recommendations for creating video were highlighted, the conditions and tasks of using video materials in the educational process were substantiated. Experience allowed us to identify the possibilities of video materials in the modern learning process, which can significantly increase the effectiveness of the teaching activities of the teacher and increase the level of students' perception of the material.Este artículo está dedicado a la creación y uso de videoclips educativos en instituciones de educación superior. Este artículo analiza los resultados de estudios sobre el impacto del contenido de video en los oyentes, que mostraron un alto grado de impacto positivo, presenta un análisis teórico de los conceptos básicos del desarrollo de materiales de video. El propósito del artículo es crear una tecnología para desarrollar videos instructivos en una institución de educación superior. Los autores presentaron la experiencia de implementar materiales de video en el aula sobre disciplinas pedagógicas. Se propusieron las etapas de desarrollo de los materiales de video, se resaltaron las recomendaciones para la creación de video, se confirmaron las condiciones y las tareas de uso de materiales de video en el proceso educativo. La experiencia nos permitió identificar las posibilidades de los materiales de video en el proceso de aprendizaje moderno, lo que puede aumentar significativamente la efectividad de las actividades de enseñanza del maestro y aumentar el nivel de percepción del material por parte de los estudiantes.Данная статья посвящена вопросам создания и использования учебных видео-роликов в высших учебных заведениях. В данной статье проанализированы результаты исследований влияния видео-контента на слушателей, показавшие большую степень положительного воздействия, представлен теоретический анализ основ разработки видео-материалов. Цель статьи состоит в создании технологии разработки обучающего видео в условиях высшего образовательного учреждения. Авторами представлен опыт реализации видео-материалов на занятиях по педагогическим дисциплинам. Были предложены этапы разработки видео-материалов, выделены рекомендации к созданию видео, обоснованы условия и задачи использования видео-материалов в учебном процессе. Опыт позволил выявить возможности видео-материалов в современном процессе обучения, которые позволяют существенно повысить результативность обучающей деятельности преподавателя и увеличить уровень восприятия студентами материала

Cardiac dysfunction in the diabetic rat: quantitative evaluation using high resolution magnetic resonance imaging

BACKGROUND: Diabetes is a major risk factor for cardiovascular disease. In particular, type 1 diabetes compromises the cardiac function of individuals at a relatively early age due to the protracted course of abnormal glucose homeostasis. The functional abnormalities of diabetic myocardium have been attributed to the pathological changes of diabetic cardiomyopathy. METHODS: In this study, we used high field magnetic resonance imaging (MRI) to evaluate the left ventricular functional characteristics of streptozotocin treated diabetic Sprague-Dawley rats (8 weeks disease duration) in comparison with age/sex matched controls. RESULTS: Our analyses of EKG gated cardiac MRI scans of the left ventricle showed a 28% decrease in the end-diastolic volume and 10% increase in the end-systolic volume of diabetic hearts compared to controls. Mean stroke volume and ejection fraction in diabetic rats were decreased (48% and 28%, respectively) compared to controls. Further, dV/dt changes were suggestive of phase sensitive differences in left ventricular kinetics across the cardiac cycle between diabetic and control rats. CONCLUSION: Thus, the MRI analyses of diabetic left ventricle suggest impairment of diastolic and systolic hemodynamics in this rat model of diabetic cardiomyopathy. Our studies also show that in vivo MRI could be used in the evaluation of cardiac dysfunction in this rat model of type 1 diabetes

Time-Dependent Alterations in Rat Macrovessels with Type 1 Diabetes

Vascular complications are associated with the progressive severity of diabetes, resulting in significant morbidity and mortality. This study quantifies functional vascular parameters and macrovascular structure in a rat model of type 1 diabetes. While there was no difference in the systemic arterial elastance (Ea) with 50 days of diabetes, changes were noted in the aorta and femoral artery including increased tunica media extracellular matrix content, decreased width of both the media and individual smooth muscle cell layers, and increased incidence of damaged mitochondria. Extracellular matrix proteins and elastin levels were significantly greater in the aorta of diabetic animals. These differences correlated with diminished matrix metalloprotease activity in the aorta of the diabetic animals. In conclusion, diabetes significantly altered the structure and ultrastructure of the aorta and femoral artery before systemic changes in arterial elastance could be detected