The Experts below are selected from a list of 19602 Experts worldwide ranked by ideXlab platform
Jan Christoph - One of the best experts on this subject based on the ideXlab platform.
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high resolution optical measurement of cardiac restitution contraction and fibrillation dynamics in beating vs blebbistatin uncoupled isolated rabbit hearts
Frontiers in Physiology, 2020Co-Authors: Vineesh Kappadan, Saba Telele, Ilija Uzelac, Flavio H Fenton, Ulrich Parlitz, Stefan Luther, Jan ChristophAbstract:Optical mapping is a high-resolution Fluorescence Imaging Technique, that uses voltage- or calcium-sensitive dyes to visualize electrical excitation waves on the heart surface. However, optical mapping is very susceptible to the motion of cardiac tissue, which results in so-called motion artifacts in the Fluorescence signal. To avoid motion artifacts, contractions of the heart muscle are typically suppressed using pharmacological excitation-contraction uncoupling agents, such as Blebbistatin. The use of pharmacological agents, however, may influence cardiac electrophysiology. Recently, it has been shown that numerical motion tracking can significantly reduce motion-related artifacts in optical mapping, enabling the simultaneous optical measurement of cardiac electrophysiology and mechanics. Here, we combine ratiometric optical mapping with numerical motion tracking to further enhance the robustness and accuracy of these measurements. We evaluate the method's performance by Imaging and comparing cardiac restitution and ventricular fibrillation (VF) dynamics in contracting, non-working versus Blebbistatin-arrested Langendorff-perfused rabbit hearts ($N=10$). We found action potential durations (APD) to be, on average, $25 \pm 5 \%$ shorter in contracting hearts compared to hearts uncoupled with Blebbistatin. The relative shortening of the APD was found to be larger at higher frequencies. VF was found to be significantly accelerated in contracting hearts, i.e., $9 \pm 2 Hz$ with Blebbistatin and $15 \pm 4 Hz$ without Blebbistatin ($N=10$ hearts), and maintained a broader frequency spectrum. In contracting hearts, the average number of phase singularities was $N_{PS} = 11 \pm 4$ compared to $N_{PS} = 6 \pm 3$ with Blebbistatin during VF on the anterior left ventricular surface. VF inducibility was reduced with Blebbistatin. We found the effect of Blebbistatin to be concentration-dependent and reversible by washout. Aside from the electrophysiological characterization, we also measured and analyzed cardiac motion. Our findings may have implications for the interpretation of optical mapping data, and highlight that physiological conditions, such as oxygenation and metabolic demand, must be carefully considered in ex vivo Imaging experiments.
Wenwen Zeng - One of the best experts on this subject based on the ideXlab platform.
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Whole-tissue 3D Imaging reveals intra-adipose sympathetic plasticity regulated by NGF-TrkA signal in cold-induced beiging
SpringerOpen, 2018Co-Authors: Ying Cao, Huanhuan Wang, Wenwen ZengAbstract:Abstract Sympathetic arborizations act as the essential efferent signals in regulating the metabolism of peripheral organs including white adipose tissues (WAT). However, whether these local neural structures would be of plastic nature, and how such plasticity might participate in specific metabolic events of WAT, remains largely uncharacterized. In this study, we exploit the new volume Fluorescence-Imaging Technique to observe the significant, and also reversible, plasticity of intra-adipose sympathetic arborizations in mouse inguinal WAT in response to cold challenge. We demonstrate that this sympathetic plasticity depends on the cold-elicited signal of nerve growth factor (NGF) and TrkA receptor. Blockage of NGF or TrkA signaling suppresses intra-adipose sympathetic plasticity, and moreover, the cold-induced beiging process of WAT. Furthermore, we show that NGF expression in WAT depends on the catecholamine signal in cold challenge. We therefore reveal the key physiological relevance, together with the regulatory mechanism, of intra-adipose sympathetic plasticity in the WAT metabolism
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Three-dimensional volume Fluorescence-Imaging of vascular plasticity in adipose tissues
Elsevier, 2018Co-Authors: Ying Cao, Huanhuan Wang, Qi Wang, Xiangli Han, Wenwen ZengAbstract:Objective: The vascular system is central to sustaining tissue survival and homeostasis. Blood vessels are densely present in adipose tissues and exert essential roles in their metabolism. However, conventional immunohistochemistry methods have intrinsic limitations in examining the 3D vascular network in adipose tissues as well as other organs in general. Methods: We established a 3D volume Fluorescence-Imaging Technique to visualize the vasculatures in mouse adipose tissues by combining the optimized steps of whole-mount immunolabeling, tissue optical clearing, and lightsheet volume Fluorescence-Imaging. To demonstrate the strength of this novel Imaging procedure, we comprehensively assessed the intra-adipose vasculatures under obese conditions or in response to a cold challenge. Results: We show the entirety of the vascular network in mouse adipose tissues on the whole-tissue level at a single-capillary resolution for the first time in the field. We accurately quantify the pathological changes of vasculatures in adipose tissues in wild-type or obese mice (ob/ob, db/db, or diet-induced obesity). In addition, we identify significant and reversible changes of the intra-adipose vasculatures in the mice subjected to cold challenge (i.e., 4°). Furthermore, we demonstrate that the cold-induced vascular plasticity depends on the sympathetic-derived catecholamine signal and is involved in the beiging process of white adipose tissues. Conclusions: We report a 3D volume Fluorescence-Imaging procedure that is compatible with many areas of vascular research and is poised to serve the field in future investigations of the vascular system in adipose tissues or other research scenarios. Keywords: 3D volume Fluorescence-Imaging, Vascular plasticity, Adipose tissues, Sympathetic arborizations, Obesity, Cold-induced beigin
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dense intra adipose sympathetic arborizations are essential for cold induced beiging of mouse white adipose tissue
Cell Metabolism, 2017Co-Authors: Haochen Jiang, Ying Cao, Huanhuan Wang, Xiaofan Ding, Wenwen ZengAbstract:Efferent signals from the central nervous system represent a key layer of regulation of white adipose tissue (WAT). However, the mechanism by which efferent neural signals control WAT metabolism remains to be better understood. Here, we exploit the volume Fluorescence-Imaging Technique to visualize the neural arborizations in mouse inguinal WAT at single-fiber resolution. The Imaging reveals a dense network of sympathetic arborizations that had been previously undetected by conventional methods, with sympathetic fibers being in close apposition to > 90% of adipocytes. We demonstrate that these sympathetic fibers originate from the celiac ganglia, which are activated by cold challenge. Sympathetic-specific deletion of TrkA receptor or pharmacologic ablation by 6-hydroxydopamine abolishes these intra-adipose arborizations and, as a result, cold-induced beiging of inguinal WAT. Furthermore, we find that local sympathetic arborizations function through beta-adrenergic receptors in this beiging process. These findings uncover an essential link connecting efferent neural signals with metabolism of individual adipocytes.
Ying Cao - One of the best experts on this subject based on the ideXlab platform.
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whole tissue immunolabeling and 3d Fluorescence Imaging to visualize axon degeneration in the intact unsectioned mouse tissues
Methods of Molecular Biology, 2020Co-Authors: Ying Cao, Jing YangAbstract:Axon degeneration destructs functional connectivity of neural circuits and is one of the common, key pathological features of different neurodegenerative diseases. However, conventional histochemistry methods, which largely rely on tissue sections, have intrinsic limitations in examining the 3D distribution of axonal structures on the whole-tissue level. This technical shortcoming has continuously impeded our in-depth understanding of pathological axon degeneration in many scenarios. To overcome such drawback encountered in the research field, we describe here a general protocol of whole-tissue immunolabeling and 3D Fluorescence Imaging Technique to visualize axon degeneration in the intact, unsectioned mouse tissues. In particular, experimental steps of tissue harvesting, whole-tissue immunolabeling, tissue optical clearing, and 3D Fluorescence Imaging have been systematically optimized, which makes the protocol effective for assessing integrity of the axonal structures in a variety of tissues. Notably, it has enabled the 3D Fluorescence Imaging of chemotherapy- or traumatic injury-induced axon degeneration within the bones (e.g., femurs) or bone-containing tissues (e.g., hindpaws), which had previously been inaccessible to conventional histochemistry methods. This protocol is therefore readily compatible with many areas of the research on axon degeneration and is poised to serve the field in future investigations.
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Whole-tissue 3D Imaging reveals intra-adipose sympathetic plasticity regulated by NGF-TrkA signal in cold-induced beiging
SpringerOpen, 2018Co-Authors: Ying Cao, Huanhuan Wang, Wenwen ZengAbstract:Abstract Sympathetic arborizations act as the essential efferent signals in regulating the metabolism of peripheral organs including white adipose tissues (WAT). However, whether these local neural structures would be of plastic nature, and how such plasticity might participate in specific metabolic events of WAT, remains largely uncharacterized. In this study, we exploit the new volume Fluorescence-Imaging Technique to observe the significant, and also reversible, plasticity of intra-adipose sympathetic arborizations in mouse inguinal WAT in response to cold challenge. We demonstrate that this sympathetic plasticity depends on the cold-elicited signal of nerve growth factor (NGF) and TrkA receptor. Blockage of NGF or TrkA signaling suppresses intra-adipose sympathetic plasticity, and moreover, the cold-induced beiging process of WAT. Furthermore, we show that NGF expression in WAT depends on the catecholamine signal in cold challenge. We therefore reveal the key physiological relevance, together with the regulatory mechanism, of intra-adipose sympathetic plasticity in the WAT metabolism
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Three-dimensional volume Fluorescence-Imaging of vascular plasticity in adipose tissues
Elsevier, 2018Co-Authors: Ying Cao, Huanhuan Wang, Qi Wang, Xiangli Han, Wenwen ZengAbstract:Objective: The vascular system is central to sustaining tissue survival and homeostasis. Blood vessels are densely present in adipose tissues and exert essential roles in their metabolism. However, conventional immunohistochemistry methods have intrinsic limitations in examining the 3D vascular network in adipose tissues as well as other organs in general. Methods: We established a 3D volume Fluorescence-Imaging Technique to visualize the vasculatures in mouse adipose tissues by combining the optimized steps of whole-mount immunolabeling, tissue optical clearing, and lightsheet volume Fluorescence-Imaging. To demonstrate the strength of this novel Imaging procedure, we comprehensively assessed the intra-adipose vasculatures under obese conditions or in response to a cold challenge. Results: We show the entirety of the vascular network in mouse adipose tissues on the whole-tissue level at a single-capillary resolution for the first time in the field. We accurately quantify the pathological changes of vasculatures in adipose tissues in wild-type or obese mice (ob/ob, db/db, or diet-induced obesity). In addition, we identify significant and reversible changes of the intra-adipose vasculatures in the mice subjected to cold challenge (i.e., 4°). Furthermore, we demonstrate that the cold-induced vascular plasticity depends on the sympathetic-derived catecholamine signal and is involved in the beiging process of white adipose tissues. Conclusions: We report a 3D volume Fluorescence-Imaging procedure that is compatible with many areas of vascular research and is poised to serve the field in future investigations of the vascular system in adipose tissues or other research scenarios. Keywords: 3D volume Fluorescence-Imaging, Vascular plasticity, Adipose tissues, Sympathetic arborizations, Obesity, Cold-induced beigin
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dense intra adipose sympathetic arborizations are essential for cold induced beiging of mouse white adipose tissue
Cell Metabolism, 2017Co-Authors: Haochen Jiang, Ying Cao, Huanhuan Wang, Xiaofan Ding, Wenwen ZengAbstract:Efferent signals from the central nervous system represent a key layer of regulation of white adipose tissue (WAT). However, the mechanism by which efferent neural signals control WAT metabolism remains to be better understood. Here, we exploit the volume Fluorescence-Imaging Technique to visualize the neural arborizations in mouse inguinal WAT at single-fiber resolution. The Imaging reveals a dense network of sympathetic arborizations that had been previously undetected by conventional methods, with sympathetic fibers being in close apposition to > 90% of adipocytes. We demonstrate that these sympathetic fibers originate from the celiac ganglia, which are activated by cold challenge. Sympathetic-specific deletion of TrkA receptor or pharmacologic ablation by 6-hydroxydopamine abolishes these intra-adipose arborizations and, as a result, cold-induced beiging of inguinal WAT. Furthermore, we find that local sympathetic arborizations function through beta-adrenergic receptors in this beiging process. These findings uncover an essential link connecting efferent neural signals with metabolism of individual adipocytes.
R Mevel - One of the best experts on this subject based on the ideXlab platform.
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optical regime diagram of the shock tube pulsed laser induced Fluorescence Imaging Technique
Chemical Physics Letters, 2019Co-Authors: R MevelAbstract:Abstract A laser-induced Fluorescence (LIF) model has been employed to characterize the shock tube/pulsed laser-induced Fluorescence Imaging method. The LIF model was first validated using experimental data for the reactions of H-abstraction by OH on benzene and toluene. The model was then employed to establish optical regime diagrams. Three regimes were distinguished: (i) the optically-thin regime, in which the rate constant obtained is not much affected by laser light absorption; (ii) the optically-thick regime, in which the laser absorption induces a significant error on the rate constant; and (iii) the so-called “non-physical” regime, in which the rate constant is negative.
Insuck Baek - One of the best experts on this subject based on the ideXlab platform.
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multispectral Fluorescence Imaging Technique for on line inspection of fecal residues on poultry carcasses
Sensors, 2019Co-Authors: Youngwook Seo, Insuck Baek, M.s. Kim, Hoonsoo Lee, Jae Young Lee, Byoung-kwan ChoAbstract:Rapid and reliable inspection of food is essential to ensure food safety, particularly in mass production and processing environments. Many studies have focused on spectral Imaging for poultry inspection; however, no research has explored the use of multispectral Fluorescence Imaging (MFI) for on-line poultry inspection. In this study, the feasibility of MFI for on-line detection of fecal matter from the ceca, colon, duodenum, and small intestine of poultry carcasses was investigated for the first time. A multispectral line-scan Fluorescence Imaging system was integrated with a commercial poultry conveying system, and the images of chicken carcasses with fecal contaminants were scanned at processing line speeds of one, three, and five birds per second. To develop an optimal detection and classification algorithm to distinguish upper and lower feces-contaminated parts from skin, the principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) were first performed using the spectral data of the selected regions, and then applied in spatial domain to visualize the feces-contaminated area based on binary images. Our results demonstrated that for the spectral data analysis, both the PCA and PLS-DA can distinguish the high and low feces-contaminated area from normal skin; however, the PCA analysis based on selected band ratio images (F630 nm/F600 nm) exhibited better visualization and discrimination of feces-contaminated area, compared with the PLS-DA-based developed chemical images. A color image analysis using histogram equalization, sharpening, median filter, and threshold value (1) demonstrated 78% accuracy. Thus, the MFI system can be developed utilizing the two band ratios for on-line implementation for the effective detection of fecal contamination on chicken carcasses.
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optimal Fluorescence waveband determination for detecting defective cherry tomatoes using a Fluorescence excitation emission matrix
Sensors, 2014Co-Authors: Insuck Baek, Moon S. Kim, Hoosoo Lee, Wang-hee Lee, Byoung-kwan ChoAbstract:A multi-spectral Fluorescence Imaging Technique was used to detect defective cherry tomatoes. The Fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal Fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA) was applied to the Fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral Fluorescence Imaging has potential utility in non-destructive quality sorting of cherry tomatoes.
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determination of optimal excitation and emission wavebands for detection of defect cherry tomato by using Fluorescence emission and excitation matrix
Proceedings of SPIE, 2013Co-Authors: Insuck BaekAbstract:Fluorescence Imaging Technique has been widely used for quality and safety measurements of agro-food materials. Fluorescence emission intensities of target materials are influenced by wavelengths of excitation sources. Hence, selection of a proper excitation wavelength is an important factor in differentiating target materials effectively. In this study, optimal Fluorescence excitation wavelength was determined on the basis of Fluorescence emission intensity of defect and sound areas of cherry tomatoes. The result showed that Fluorescence responses of defect and sound surfaces of cherry tomatoes were most significantly separated with the excitation light wavelength range between 400 and 410 nm. Fluorescence images of defect cherry tomatoes were acquired with the LEDs with the central wavelength of 410 nm as the excitation source to verify the detection efficiency of cherry tomato defects. The resultant Fluorescence images showed that the defects were discriminated from sound areas on cherry tomatoes with above 98% accuracy. This study shows that high power LEDs as the excitation source for Fluorescence Imaging are suitable for defect detection of cherry tomatoes.
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Detection of cuticle defects on cherry tomatoes using hyperspectral Fluorescence imagery
Postharvest Biology and Technology, 2013Co-Authors: Insuck BaekAbstract:Abstract Cherry tomatoes are one of the major vegetables consumed in the fresh-cut market. However, the quality evaluation process, which is dependent on simple size- or color-sorting Techniques, is inadequate to meet increased consumer demands for high quality and safety. Among various quality evaluations, detection of cracking defects in cherry tomatoes is a critical process since this type of damage can harbor pathogenic microbes that may have detrimental consequences on consumer health. In this study, a multi-spectral Fluorescence Imaging Technique has been presented as a diagnostic tool for non-destructive detection of defective cherry tomatoes. Fluorescence intensity in the area of cracked cuticle was significantly higher in the blue-green spectral region than that of the sound surfaces, suggesting the multi-spectral Fluorescence Imaging Technique as an effective classification tool for detecting cracking defects on cherry tomatoes. Simple ANOVA classification analysis and principal component analysis were employed to investigate optimal Fluorescence wavebands. The results illustrate that a multi-spectral Fluorescence image in linear combination with a pair of selected wavebands based on the results of ANOVA analysis was able to detect defective cherry tomatoes with >99% accuracy. The detection algorithm investigated in this study is expected to be used to develop on-site and real-time multi-spectral systems for quality evaluation of cherry tomatoes in postharvest processing plants.