1. Articles in category: Developmental Biology

    121-144 of 252 « 1 2 ... 3 4 5 6 7 8 9 10 11 »
    1. Translational paradigms in scientific and clinical imaging of cardiac development

      Translational paradigms in scientific and clinical imaging of cardiac development

      Congenital heart defects (CHD) are the most prevalent congenital disease, with 45% of deaths resulting from a congenital defect due to a cardiac malformation. Clinically significant CHD permit survival upon birth, but may become immediately life threatening. Advances in surgical intervention have significantly reduced perinatal mortality, but the outcome for many malformations is bleak. Furthermore, patients living while tolerating a CHD often acquire additional complications due to the long-term systemic blood flow changes caused by even subtle anatomical abnormalities. Accurate diagnosis of defects during fetal development is critical for interventional planning and improving patient outcomes. Advances in quantitative, multidimensional imaging ...

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    2. Baylor College Receives NIH Granbt for Biomechanics of Early Mammalian Cardiogenesis

      Baylor College Receives NIH Granbt for Biomechanics of Early Mammalian Cardiogenesis

      Baylor College of Medicine received a 2013 NIH grant for $386,700 to study biomechanics of early mammalian cardiogenesis. The principal investigator is Irina Larina. The program began in 2013 and ends in 2018. Below is a summary of the proposed work. Congenital heart defects are among the most common birth defects and the leading cause of death in children born with congenital defects. Understanding how the early embryonic heart functions and what regulatory mechanisms are involved in early cardiogenesis is highly important for advancement of heart defects research. Biomechanical stimuli, including blood flow and heart contraction, are important regulators ...

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    3. OHSU Receives NIH Grant for Dynamic Changes In The Chick Developing Heart In Response to Altered Hemodynamics

      OHSU Receives NIH Grant for Dynamic Changes In The Chick Developing Heart In Response to Altered Hemodynamics

      Oregon Health and Science University received a 2013 NIH Grant for $405,572 for Dynamic Changes In The Chick Developing Heart In Response to Altered Hemodynamics. The principal investigator is Sandra Rugonyi. The program started in 2008 and lends in 2018. A summary of the program is given below. About 1% newborn babies have congenital heart disease (CHD), the leading cause of death among children. The majority of CHD cases are believed not to have a genetic cause. Other factors, such as abnormal blood flow during embryonic and fetal stages can lead to heart malformations and thus CHD through poorly ...

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    4. Case Western Reserve University Receives NIH Grant for Integrated Imaging of The Form and Function of The Beating Embryonic Heart

      Case Western Reserve University Receives NIH Grant for Integrated Imaging of The Form and Function of The Beating Embryonic Heart

      Case Western Reserve University Received a 2013 NIH Grant for $620,585 for Integrated Imaging of The Form and Function of The Beating Embryonic Heart. The principle investigator is Andrew Rollins. The program began in 2006 and ends in 2017. Below is a summary of the proposed study. Congenital heart defects (CHDs) afflict 36,000 babies born in the US each year and survivors often require several surgical interventions in their shortened lifetime. Despite continuous efforts, the mechanisms leading to CHDs remain largely unclear. In part, this is because most developmental cardiology studies fail to address the influential role of ...

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    5. High-resolution optical coherence tomography in mouse models of genetic and induced retinal degeneration

      High-resolution optical coherence tomography in mouse models of genetic and induced retinal degeneration

      For the study of disease mechanisms and the development of novel therapeutic strategies for retinal pathologies in human, rodent models play an important role. Nowadays, optical coherence tomography (OCT) allows three-dimensional investigation of retinal events over time. However, a detailed analysis of how different retinal degenerations are reflected in OCT images is still lacking in the biomedical field. Therefore, we use OCT to visualize retinal degeneration in specific mouse models in order to study disease progression in vivo and improve image interpretation of this noninvasive modality. We use a self-developed spectral domain OCT system for simultaneous dual-band imaging in the ...

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    6. Alterations in Pulse Wave Propagation Reflect the Degree of Outflow Tract Banding in HH18 Chicken Embryos

      Alterations in Pulse Wave Propagation Reflect the Degree of Outflow Tract Banding in HH18 Chicken Embryos

      Hemodynamic conditions play a critical role in embryonic cardiovascular development, and altered blood flow leads to congenital heart defects. Chicken embryos are frequently used as models of cardiac development, with abnormal blood flow achieved through surgical interventions such as outflow tract (OFT) banding, in which a suture is tightened around the heart OFT to restrict blood flow. Banding in embryos increases blood pressure and alters blood flow dynamics, leading to cardiac malformations similar to those seen in human congenital heart disease. In studying these hemodynamic changes, synchronization of data to the cardiac cycle is challenging, and alterations in the timing ...

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    7. Silencing Of The Drosophila Ortholog Of SOX5 In Heart Leads To Cardiac Dysfunction As Detected By Optical Coherence Tomography

      Silencing Of The Drosophila Ortholog Of SOX5 In Heart Leads To Cardiac Dysfunction As Detected By Optical Coherence Tomography

      The SRY-related HMG-box 5 (SOX5) gene encodes a member of the SOX family of transcription factors. Recently, genome-wide association studies have implicated SOX5 as a candidate gene for susceptibility to four cardiac-related endophenotypes: higher resting heart rate (RHR), the electrocardiographic PR interval, atrial fibrillation (AF) and left ventricular mass (LVM). We have determined that human SOX5 has a highly conserved Drosophila ortholog, Sox102F, and have employed transgenic Drosophila models to quantitatively measure cardiac function in adult flies. For this purpose, we have developed a high-speed and ultrahigh-resolution optical coherence tomography (OCT) imaging system, which enables rapid cross-sectional imaging of the ...

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    8. Assessment and In Vivo Scoring of Murine Experimental Autoimmune Uveoretinitis Using Optical Coherence Tomography

      Assessment and In Vivo Scoring of Murine Experimental Autoimmune Uveoretinitis Using Optical Coherence Tomography

      Despite advances in clinical imaging and grading our understanding of retinal immune responses and their morphological correlates in experimental autoimmune uveoretinitis (EAU), has been hindered by the requirement for post-mortem histology. To date, monitoring changes occurring during EAU disease progression and evaluating the effect of therapeutic intervention in real time has not been possible. We wanted to establish whether optical coherence tomography (OCT) could detect intraretinal changes during inflammation and to determine its utility as a tool for accurate scoring of EAU. EAU was induced in C57BL/6J mice and animals evaluated after 15, 26, 36 and 60 days. At ...

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    9. Case Western Reserve University Receives NIH Grant for Investigating Optical Pacing of the Embryonic Heart

      Case Western Reserve University Receives NIH Grant for Investigating Optical Pacing of the Embryonic Heart

      Case Western Reserve University Received a 2013 NIH Grant for $176,625 for Investigating Optical Pacing of the Embryonic Heart. The principal investigator is Michael Jenkins. The program started in 2012 and ends in 2014. Below is a summary of the proposed work. Our long-term objective is to determine the influence biophysical forces have on heart development and how alterations of these forces early in development can lead to congenital heart defects (CHDs). CHDs are extremely prevalent affecting almost 36,000 newborns in the US each year, or 9 out of 1,000 live births. In order to tease apart ...

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    10. OCT guided microinjections for mouse embryonic research

      OCT guided microinjections for mouse embryonic research

      Optical coherence tomography (OCT) is gaining popularity as live imaging tool for embryonic research in animal models. Recently we have demonstrated that OCT can be used for live imaging of cultured early mouse embryos (E7.5-E10) as well as later stage mouse embryos in utero (E12.5 to the end of gestation). Targeted delivery of signaling molecules, drugs, and cells is a powerful approach to study normal and abnormal development, and image guidance is highly important for such manipulations. Here we demonstrate that OCT can be used to guide microinjections of gold nanoshell suspensions in live mouse embryos. This approach ...

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    11. In vivo functional imaging of embryonic chick heart using ultrafast 1310nm-band spectral domain optical coherence tomography

      In vivo functional imaging of embryonic chick heart using ultrafast 1310nm-band spectral domain optical coherence tomography

      During the cardiac development, the cardiac wall and the blood flow actively interact with each other, and determine the biomechanical environment to which the embryonic heart exposes. Employing an ultrafast 1310nm-band dual-camera spectral domain optical coherence tomography (SDOCT), the radial strain rate of the myocardial wall can be extracted with high signal-to-noise ratio, at the same time the Doppler velocity of the blood flow can also be displayed. The ability to simultaneously characterize these two cardiac tissues provides a powerful approach to better understand the interaction between the cardiac wall and the blood flow, which is important to the investigation ...

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    12. Changes in strain and blood flow in the outflow tract of chicken embryo hearts observed with spectral domain optical coherence tomography after outflow tract banding

      Changes in strain and blood flow in the outflow tract of chicken embryo hearts observed with spectral domain optical coherence tomography after outflow tract banding

      In this paper, we demonstrated the use of a spectral domain optical coherence tomography (OCT) in visualizing and quantifying changes in cardiac wall strain and blood-flow velocities under normal and altered hemodynamic conditions in chicken embryos at an early stage of development, focusing on the heart outflow tract (OFT). OCT imaging allowed in vivo evaluation strain and strain rate of the myocardium of the OFT through analyzing the periodic variation of the myocardial wall thickness. We found that alterations in hemodynamic conditions, through OFT banding, Changed strain and blood-flow velocities through the OFT as expected.

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    13. Critical Transitions in Early Embryonic Aortic Arch Patterning and Hemodynamics

      Critical Transitions in Early Embryonic Aortic Arch Patterning and Hemodynamics

      Transformation from the bilaterally symmetric embryonic aortic arches to the mature great vessels is a complex morphogenetic process, requiring both vasculogenic and angiogenic mechanisms. Early aortic arch development occurs simultaneously with rapid changes in pulsatile blood flow, ventricular function, and downstream impedance in both invertebrate and vertebrate species. These dynamic biomechanical environmental landscapes provide critical epigenetic cues for vascular growth and remodeling. In our previous work, we examined hemodynamic loading and aortic arch growth in the chick embryo at Hamburger-Hamilton stages 18 and 24. We provided the first quantitative correlation between wall shear stress (WSS) and aortic arch diameter in ...

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    14. A Spinal Cord Window Chamber Model for In Vivo Longitudinal Multimodal Optical and Acoustic Imaging in a Murine Model

      A Spinal Cord Window Chamber Model for In Vivo Longitudinal Multimodal Optical and Acoustic Imaging in a Murine Model

      In vivo and direct imaging of the murine spinal cord and its vasculature using multimodal (optical and acoustic) imaging techniques could significantly advance preclinical studies of the spinal cord. Such intrinsically high resolution and complementary imaging technologies could provide a powerful means of quantitatively monitoring changes in anatomy, structure, physiology and function of the living cord over time after traumatic injury, onset of disease, or therapeutic intervention. However, longitudinal in vivo imaging of the intact spinal cord in rodent models has been challenging, requiring repeated surgeries to expose the cord for imaging or sacrifice of animals at various time points ...

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    15. Semiautomatic and rapid quantification of heartbeat parameters in Drosophila using optical coherence tomography imaging

      Semiautomatic and rapid quantification of heartbeat parameters in Drosophila using optical coherence tomography imaging

      We report a semiautomatic algorithm that is specialized for rapid analysis of beat-to-beat contraction-relaxation parameters of the heart in Drosophila . The presented algorithm adapts the general graph theoretical image segmentation algorithm and a histogram-based thresholding algorithm, which can measure many cardiac parameters, including heart rate, heart period, diastolic and systolic intervals, and end-diastolic and end-systolic areas. Additionally, dynamic cardiac functions, such as arrhythmia index and percent fractional shortening, can be automatically calculated for all the recorded heartbeats over significant periods of time.

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    16. OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University

      OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University

      Jing-Gao Zheng from Tsinghua University was a winner of the 2013 OCT News Student Paper Award for his submission “Understanding early patterning and polarity of preimplantation mouse embryos with full-field optical coherence tomography.” Below is a summary of his work:  Morphogenetic relationship between early patterning and the polarity formation is of fundamental interest and remains controversial issues in mammalian preimplantation development. Label-free subcellular 3D live imaging technique is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for non-invasive 3D sub-cellular live imaging of preimplantation mouse embryos with no need of ...

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    17. Understanding three-dimensional spatial relationship between the mouse second polar body and first cleavage plane with full-field optical coherence tomography

      Understanding three-dimensional spatial relationship between the mouse second polar body and first cleavage plane with full-field optical coherence tomography

      he morphogenetic relationship between early patterning and polarity formation is of fundamental interest and remains a controversial issue in preimplantation embryonic development. We use a label-free three-dimensional (3-D) imaging technique of full-field optical coherence tomography (FF-OCT) successfully for the first time to study the dynamics of developmental processes in mouse preimplantation lives. Label-free 3-D subcellular time-lapse images are demonstrated to investigate 3-D spatial relationship between the second polar body (2PB) and the first cleavage plane. By using FF-OCT together with quantitative study, we show that only 25% of the predicted first cleavage planes, defined by the apposing plane of two ...

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    18. 4D Reconstruction of the Beating Embryonic Heart From Two Orthogonal Sets of Parallel Optical Coherence Tomography Slice-Sequences

      4D Reconstruction of the Beating Embryonic Heart From Two Orthogonal Sets of Parallel Optical Coherence Tomography Slice-Sequences

      Current methods to build dynamic optical coherence tomography (OCT) volumes of the beating embryonic heart involve synchronization of 2D+time slice-sequences acquired over separate heartbeats. Temporal registration of these sequences is performed either through gating or post-processing. While synchronization algorithms that exclusively rely on image-intrinsic signals allow forgoing external gating hardware, they are prone to error accumulation, require operator-supervised correction, or lead to non-isotropic resolution. Here, we propose an imagebased, retrospective reconstruction technique that uses two sets of parallel 2D+T slice-sequences, acquired perpendicularly to each other, to yield accurate and automatic reconstructions with isotropic resolution. The method utilizes the ...

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    19. Oregon Health and Science University Receiveds NIH Grant f for 3-D Optical Imaging of The In Vivo Organ of Corti Motion at a Sub-Nanometer Scale

      Oregon Health and Science University Receiveds NIH Grant f for 3-D Optical Imaging of The In Vivo Organ of Corti Motion at a Sub-Nanometer Scale

      The Oregon Health and Science University Received a 2012 a NIH Grant for $310,929 for 3-D Optical Imaging of The In Vivo Organ of Corti Motion at a Sub-Nanometer Scale. The principal investigator is Alfred Nuttall. The program began in 2009 and ends in 2013. Below is a summary of the work. Low optical coherence tomography (OCT) has been used to image biological tissue and is the theoretical basis of microscopes that are commercially available to image the lens and cellular structures of the human eye. Interferometers based on OCT have not been produced but have unique properties useful ...

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    20. Optical coherence tomography provides an ability to assess mechanical property of cardiac wall of developing outflow tract in embryonic heart in vivo

      Optical coherence tomography provides an ability to assess mechanical property of cardiac wall of developing outflow tract in embryonic heart in vivo

      Knowledge of the biomechanical/elastic property of the cardiac wall is of fundamental importance in improving our understanding of cardiac development, particularly the interaction between the wall dynamics and hemodynamics in the developing outflow tract (OFT). We describe a method that employs optical coherence tomography (OCT) as a means to noninvasively measure the local elastic property of the cardiac wall in vivo . The method uses a time-lapse sequence of OCT images that represent the dynamic behavior of the OFT longitudinal section to calculate the regional wall pulse wave velocity (PWV), upon which the Young’s modulus of the cardiac wall ...

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    21. Noninvasive imaging of heart chamber in Drosophila with dual-beam optical coherence tomography

      Noninvasive imaging of heart chamber in Drosophila with dual-beam optical coherence tomography

      The heart chamber of an adult Drosophila is approximately 2 mm long and 0.5 mm wide, and the interwall separation of different heart portions during systole and diastole range from tens of micrometers to hundreds of micrometers. Furthermore, the heart chamber has a curved structure, which results in the larger differences in depth between the different heart portions. However, applying the wavelength calibration process before Fourier transform in an optical coherence tomography (OCT) system may cause degradation in system sensitivity and longitudinal resolution when the optical path difference between the reference and sample arms increases, which makes imaging the ...

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    22. Phenotyping of Mouse Models with OCT

      Phenotyping of Mouse Models with OCT

      Optical coherence tomography (OCT) is an invaluable technique to perform noninvasive retinal imaging in small animal models such as mice. It provides virtual cross sections that correlate well with histomorphometric data with the advantage that multiple iterative measurements can be acquired in time line analyses to detect dynamic changes and reduce the amount of animals needed per study.

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    23. 4D shear stress maps of the developing heart using Doppler optical coherence tomography

      4D shear stress maps of the developing heart using Doppler optical coherence tomography

      Accurate imaging and measurement of hemodynamic forces is vital for investigating how physical forces acting on the embryonic heart are transduced and influence developmental pathways. Of particular importance is blood flow-induced shear stress, which influences gene expression by endothelial cells and potentially leads to congenital heart defects through abnormal heart looping, septation, and valvulogenesis. However no imaging tool has been available to measure shear stress on the endocardium volumetrically and dynamically. Using 4D structural and Doppler OCT imaging, we are able to accurately measure the blood flow in the heart tube in vivo and to map endocardial shear stress throughout ...

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    24. First-ever 3-D Stress Map of Developing Embryonic Heart Sheds Light on Why Defects Form

      First-ever 3-D Stress Map of Developing Embryonic Heart Sheds Light on Why Defects Form

      Forces inside the beating heart of a human embryo help determine health of a baby’s heart: new 3-D images map these important forces As a human fetus develops, its heart has to keep pace with the new body’s ever-growing demands. Much of this is controlled by following genetic blueprints, but the embryonic heart also matures in response to the intense stresses of pumping blood. For the first time, researchers have been able to visualize in 3-D the stresses induced by flowing blood in an embryonic heart. The technique, which promises to provide new insight into how and why ...

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    121-144 of 252 « 1 2 ... 3 4 5 6 7 8 9 10 11 »
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