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المصدر: Journal of the Royal Society, Interface. 14(127)
مصطلحات موضوعية: 0301 basic medicine, Pathology, medicine.medical_specialty, Biomedical Engineering, Biophysics, Bioengineering, Biology, Biochemistry, Models, Biological, Biomaterials, 03 medical and health sciences, Oxygen Consumption, Application areas, medicine, Animals, Humans, Muscle, Skeletal, Review Articles, Microscopy, Confocal, Skeletal muscle, Oxygenation, 030104 developmental biology, Tissue oxygenation, medicine.anatomical_structure, Neuroscience, Image based, Biotechnology
الوصف: The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, in particular for skeletal muscle during exercise. Disease is often associated with both an inhibition of the microvascular supply capability and is thought to relate to changes in the structure of blood vessel networks. Different methods exist to investigate the influence of the microvascular structure on tissue oxygenation, varying over a range of application areas, i.e. biologicalin vivoandin vitroexperiments, imaging and mathematical modelling. Ideally, all of these methods should be combined within the same framework in order to fully understand the processes involved. This review discusses the mathematical models of skeletal muscle oxygenation currently available that are based upon images taken of the muscle microvasculaturein vivoandex vivo. Imaging systems suitable for capturing the blood vessel networks are discussed and respective contrasting methods presented. The review further informs the association between anatomical characteristics in health and disease. With this review we give the reader a tool to understand and establish the workflow of developing an image-based model of skeletal muscle oxygenation. Finally, we give an outlook for improvements needed for measurements and imaging techniques to adequately investigate the microvascular capability for oxygen exchange.
وصف الملف: text
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f82d4ebe75f27a7058e576159a27a43dTest
https://pubmed.ncbi.nlm.nih.gov/28202595Test -
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المؤلفون: Geraldine F. Clough, Stephen P. Morgan, Cally Gill, H. C. Nguyen, Diwei He, Barrie Hayes-Gill, John A. Crowe, Yiqun Zhu
المصدر: Sensors, Vol 13, Iss 9, Pp 12632-12647 (2013)
Sensors (Basel, Switzerland)
Sensors; Volume 13; Issue 9; Pages: 12632-12647مصطلحات موضوعية: Engineering, imaging sensor, Transducers, Normalization (image processing), ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, laser Doppler, Analog signal processing, lcsh:Chemical technology, 01 natural sciences, Biochemistry, Signal, Sensitivity and Specificity, Article, Analytical Chemistry, 010309 optics, Sensor array, 0103 physical sciences, Electronic engineering, Laser-Doppler Flowmetry, Humans, blood flow, lcsh:TP1-1185, Electrical and Electronic Engineering, Image sensor, Instrumentation, Signal processing, Blood Volume Determination, CMOS, full field, business.industry, 010401 analytical chemistry, Detector, Reproducibility of Results, Signal Processing, Computer-Assisted, Filter (signal processing), Equipment Design, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Equipment Failure Analysis, Semiconductors, business, Blood Flow Velocity
الوصف: The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.
وصف الملف: application/pdf; PDF
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e2cb1a57b12a7420f5e142bfd2a2d0aTest
http://www.mdpi.com/1424-8220/13/9/12632Test -
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المصدر: Journal of The Royal Society Interface. 14:20170635
مصطلحات موضوعية: Male, 0301 basic medicine, Muscle tissue, Erythrocytes, Biomedical Engineering, Biophysics, Bioengineering, Biology, Biochemistry, Microcirculation, Biomaterials, Mice, 03 medical and health sciences, Oxygen Consumption, Physical Conditioning, Animal, Image Interpretation, Computer-Assisted, medicine, Skeletal Muscle Tissue, Animals, Humans, Muscle, Skeletal, Soleus muscle, Length density, Skeletal muscle, Life Sciences–Physics interface, Oxygenation, Anatomy, Oxygen, 030104 developmental biology, medicine.anatomical_structure, Synchrotrons, Image based, Biotechnology
الوصف: The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, especially for skeletal muscle during exercise. Traditionally, microvascular oxygen supply capability is assessed by the analysis of morphological measures on transverse cross-sections of muscle, e.g. capillary density or capillary-to-fibre ratio. In this work, we investigate the relationship between microvascular structure and muscle tissue oxygenation in mice. Phase contrast imaging was performed using synchrotron radiation computed tomography (SR CT) to visualize red blood cells (RBCs) within the microvasculature in mouse soleus muscle. Image-based mathematical modelling of the oxygen diffusion from the RBCs into the muscle tissue was subsequently performed, as well as a morphometric analysis of the microvasculature. The mean tissue oxygenation was then compared with the morphological measures of the microvasculature. RBC volume fraction and spacing (mean distance of any point in tissue to the closest RBC) emerged as the best predictors for muscle tissue oxygenation, followed by length density (summed RBC length over muscle volume). The two-dimensional measures of capillary density and capillary-to-fibre ratio ranked last. We, therefore, conclude that, in order to assess the states of health of muscle tissue, it is advisable to rely on three-dimensional morphological measures rather than on the traditional two-dimensional measures.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::db7ec9864073e93a5feceecdd9cf1257Test
https://doi.org/10.1098/rsif.2017.0635Test -
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المؤلفون: Christopher D. Byrne, Frits F. M. de Mul, Andrew J. Chipperfield, Rodney Gush, Geraldine F. Clough
المصدر: Microvascular research, 78(2), 155-161
مصطلحات موضوعية: Adult, Male, Laser Doppler blood flow, Optics and Photonics, Time Factors, Materials science, Sub-dermal tissue, SODIUM-NITROPRUSSIDE, Monte Carlo method, Biochemistry, Light scattering, POSSIBLE MECHANISMS, Hyperaemia, Optics, SPECTRAL-ANALYSIS, Laser-Doppler Flowmetry, medicine, Humans, Computer Simulation, Monte Carlo modeling, Reactive hyperemia, REACTIVE HYPEREMIA, IN-VIVO, Skin, NITRIC-OXIDE, integumentary system, business.industry, SYSTEMIC-SCLEROSIS, Spectral density, Equipment Design, Cell Biology, Blood flow, Potential measurement, OPTICAL-PROPERTIES, Middle Aged, Laser Doppler velocimetry, WAVELET ANALYSIS, LIGHT-SCATTERING, Skin warming, Forearm, Lower Extremity, Evaluation Studies as Topic, Regional Blood Flow, Area Under Curve, Female, medicine.symptom, Cardiology and Cardiovascular Medicine, business, Monte Carlo Method
الوصف: Objective: To compare the output from a novel high power, wide separation laser Doppler flow probe (DP1-V2-HP, 4 mm, with IRLD20) with that of a standard flow probe (DP1-V2, 0.5 mm, with DRT4) (Moor UK) and to explore its potential for use in the noninvasive measurement of blood flow in deeper tissues in humans.Methods: Monte Carlo modeling was used to predict depths of light scattering in skin with each probe, geometry. Experimentally, forearm blood flow was measured at rest and during local warming of the skin surface and post occlusion reactive hyperaemia (PORH). Laser Doppler blood flux (LDF) and the power spectral density of its component frequency intervals, were compared.Results: Monte Carlo modeling indicated that while the majority of wide probe LD signal derives from deeper tissue, a significant portion is from superficial (dermal) tissue (and vice versa for standard probe). Perturbation of local blood flow differentially increased LDF and spectral power as measured by the two probes, with the standard skin probe showing a significantly greater response to local skin warming (pConclusions: These differences support our hypothesis that the wide probe is recording predominantly blood flux within the vasculature of sub-dermal tissue. This is in agreement with Monte Carlo simulation. (C) 2009 Elsevier Inc. All rights reserved.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d7401db896238cfdd675921b801095deTest
https://doi.org/10.1016/j.mvr.2009.05.003Test -
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المصدر: Journal of Investigative Dermatology. 127(12):2799-2806
مصطلحات موضوعية: Microdialysis, Allergy, Time Factors, medicine.medical_treatment, Human skin, Dermatology, medicine.disease_cause, Biochemistry, Allergic inflammation, Interleukin-1alpha, Skin Physiological Phenomena, medicine, Cell Adhesion, Edema, Humans, Intradermal injection, Interleukin 5, Molecular Biology, Skin, Inflammation, business.industry, Interleukin-6, Tumor Necrosis Factor-alpha, Interleukin-8, Granulocyte-Macrophage Colony-Stimulating Factor, Cell Biology, Allergens, medicine.disease, Interleukin-12, Cytokine, Allergic response, Immunology, Cytokines, Interleukin-5, business
الوصف: This study examined the suitability of microdialysis to assess the time course of cytokine generation from discrete sites within the skin following intradermal injection of allergen. Cytokines were recovered using two microdialysis probes, one close to the point of allergen injection and the other 1 cm away but within the area of the late-phase induration. Skin biopsies taken at both sites were stained immunocytochemically to investigate possible relationships between cytokine generation, expression of adhesion molecules, and recruitment of neutrophils and eosinophils during the late-phase allergic response. The cytokine response to probe insertion was assessed using a single probe in the opposite arm (control). At baseline, microdialysate contained low levels of IL-1alpha, IL-5, IL-8, IL-12, GM-CSF, and TNFalpha (n=27-33). At control sites, this was followed by increases in IL-6 and IL-8 at 3 and 6 hours. Allergen increased TNFalpha levels in 3/11 individuals within 30 minutes at the injection site. Levels of IL-6 and IL-8 rose rapidly and were significantly greater (P
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::af622676795b6ed8ae2ddb9e25313bb0Test
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المصدر: Journal of Investigative Dermatology. 126(6):1220-1225
مصطلحات موضوعية: Adult, Atropine, Microdialysis, medicine.medical_specialty, Sweating, Muscarinic Antagonists, Dermatology, Muscarinic Agonists, Biochemistry, SWEAT, Norepinephrine, 03 medical and health sciences, 0302 clinical medicine, Sweat gland, Internal medicine, Muscarinic acetylcholine receptor, medicine, Humans, Molecular Biology, 030304 developmental biology, 0303 health sciences, Transepidermal water loss, integumentary system, Chemistry, Pilocarpine, Cell Biology, Middle Aged, Sweat Glands, medicine.anatomical_structure, Endocrinology, Female, Adrenergic alpha-Agonists, Perfusion, 030217 neurology & neurosurgery, medicine.drug
الوصف: Previous studies of the pharmacological regulation of sweat gland function in humans have administered agonists or antagonists systemically, by local intradermal injection or by iontophoresis. This has not allowed prolonged or steady-state activation of sweat glands to be examined. In this study, we used the technique of dermal microdialysis to administer pharmacological agents singly and in combination for up to 5 hours. Muscarinic stimulation with pilocarpine nitrate (50 mug ml(-1) to 1.66 mg ml(-1)) produced a sigmoid dose response curve, with maximal sweating (measured as transepidermal water loss) (mean 70 g m(-2) hour(-1)) after 15 minutes. This was sustained at steady-state levels (55 g m(-2) hour(-1)) until perfusion stopped. Perfusion with atropine (0.003 mg ml(-1)) reduced sweating below baseline and blocked pilocarpine-induced sweating completely. Noradrenaline (0.005 mg ml(-1)) induced much lower sweat rates than pilocarpine (56.8+/-1.62 g m(-2) hour(-1) vs 8.2+/-1.2 g m(-2) hour(-1), respectively, P
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8ad281367b027b0044b8d372ab8b5ac8Test
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المؤلفون: Michael R. Hughes, Tony Dadd, Paul Skipp, C. David O′Connor, Andrew G. Garrow, Erika Parkinson, Maja Aleksic, Geraldine F. Clough
المصدر: PLoS ONE
PLoS ONE, Vol 9, Iss 5, p e97772 (2014)مصطلحات موضوعية: Proteomics, Proteome, Proteomes, Toxic Agents, lcsh:Medicine, Human skin, Atopic Dermatitis, Dermatology, Dermatologic Pathology, Bioinformatics, Toxicology, Biochemistry, Contact Dermatitis, chemistry.chemical_compound, In vivo, Liquid chromatography–mass spectrometry, Keratin, Medicine and Health Sciences, Humans, Sodium dodecyl sulfate, lcsh:Science, Skin, chemistry.chemical_classification, Gel electrophoresis, Multidisciplinary, Spectrometric Identification of Proteins, lcsh:R, Sodium Dodecyl Sulfate, Biology and Life Sciences, Proteins, chemistry, Solubility, lcsh:Q, Research Article, Tissue Proteins
الوصف: BACKGROUND: Skin has a variety of functions that are incompletely understood at the molecular level. As the most accessible tissue in the body it often reveals the first signs of inflammation or infection and also represents a potentially valuable source of biomarkers for several diseases. In this study we surveyed the skin proteome qualitatively using gel electrophoresis, liquid chromatography tandem mass spectrometry (GeLC-MS/MS) and quantitatively using an isobaric tagging strategy (iTRAQ) to characterise the response of human skin following exposure to sodium dodecyl sulphate (SDS).RESULTS: A total of 653 skin proteins were assigned, 159 of which were identified using GeLC-MS/MS and 616 using iTRAQ, representing the most comprehensive proteomic study in human skin tissue. Statistical analysis of the available iTRAQ data did not reveal any significant differences in the measured skin proteome after 4 hours exposure to the model irritant SDS.CONCLUSIONS: This study represents the first step in defining the critical response to an irritant at the level of the proteome and provides a valuable resource for further studies at the later stages of irritant exposure.
وصف الملف: text
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c2668660afbd86a7421d73c0b6246e95Test
https://pubmed.ncbi.nlm.nih.gov/24849295Test -
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المصدر: PLoS ONE
PLoS ONE, Vol 9, Iss 5, p e97534 (2014)مصطلحات موضوعية: Blood Glucose, medicine.medical_treatment, Biochemistry, Eating, 0302 clinical medicine, Endocrinology, Heart Rate, Risk Factors, Medicine and Health Sciences, Insulin, 030212 general & internal medicine, Treadmill, Lung, 2. Zero hunger, Multidisciplinary, VO2 max, Heart, Middle Aged, 3. Good health, Type 1 Diabetes, Medicine, Engineering and Technology, Female, Research Article, Biotechnology, Adult, medicine.medical_specialty, Science, Biomedical Engineering, Blood sugar, 030209 endocrinology & metabolism, Bioengineering, 03 medical and health sciences, Bruce protocol, Oxygen Consumption, Diabetes mellitus, Internal medicine, medicine, Diabetes Mellitus, Humans, Sports and Exercise Medicine, Exercise, Monitoring, Physiologic, Diabetic Endocrinology, Type 1 diabetes, business.industry, Biology and Life Sciences, Cardiorespiratory fitness, medicine.disease, Hormones, Diabetes Mellitus, Type 1, Metabolic Disorders, Physical therapy, Exercise Test, Medical Devices and Equipment, business, Energy Metabolism
الوصف: Objective: encouraging daily physical activity improves cardiorespiratory fitness and many cardiovascular risk factors. However, increasing physical activity often creates a challenge for people with type 1 diabetes, because of difficulties maintaining euglycemia in the face of altered food intake and adjustments to insulin doses. Our aim was to examine the triangular relationship between glucose control measured by continuous glucose monitoring system (CGMS), objective measures of total daily energy expenditure (TEE) recorded by a multi-sensory monitoring device, and cardiorespiratory fitness (CRF), in free-living subjects with type 1 diabetes.Research design and methods: twenty-three individuals (12 women) with type 1 diabetes who were free from micro- and macrovascular complications were recruited. TEE and glucose control were monitored simultaneously for up to 12 days, using a multi-sensory device and CGMS respectively. CRF was recorded as V02 max from a maximal treadmill test with the Bruce protocol.Results: subjects (mean±SD) were aged 37±11 years, with BMI = 26.5±5.1 kg.m?2, HbA1c = 7.7±1.3% (61±14 mmol/mol) and V02 max (ml.min?1.kg?1) = 39.9±8.4 (range 22.4 – 58.6). TEE (36.3±5.5 kcal.kg?1.day?1) was strongly associated with CRF(39.9±8.4 ml.min?1.kg?1) independently of sex (r = 0.63, pConclusion: higher levels of energy expenditure (due to a more active lifestyle) are associated with increased cardiorespiratory fitness, but not necessarily better glycaemic control. Since increased levels of energy expenditure and good glycaemic control are both needed to protect against diabetes-related complications our data suggest they need to be achieved independently
وصف الملف: text
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bdadaea521fdd048c8f19f4426b6ffffTest
https://pubmed.ncbi.nlm.nih.gov/24826899Test -
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المؤلفون: Martin K. Church, Amanda R. Bennett, Geraldine F. Clough
المصدر: Experimental Physiology. 83:431-434
مصطلحات موضوعية: Adult, Male, Microdialysis, Injections, Intradermal, Vasodilator Agents, Human skin, Pharmacology, Nitric Oxide, Osmolar Concentration, Nitric oxide, Nitroglycerin, chemistry.chemical_compound, In vivo, Humans, Enzyme Inhibitors, Skin, Transdermal, Chemistry, General Medicine, Middle Aged, Amperometry, NG-Nitroarginine Methyl Ester, Biochemistry, Female, Histamine
الوصف: Using microdialysis, we measured nitric oxide (NO) levels in healthy human skin, in vivo, before and during the local inflammatory response to histamine. Basal dialysate NO concentration, assayed using an amperometric technique, was 0.49+/-0.06 microM (mean+/-S.E.M., 21 probes, 14 subjects). Histamine injection produced transient increases in NO concentration within both the weal and flare which was blocked by the NO synthase inhibitor, NG-nitro-L-arginine-methyl ester (L-NAME). Dialysate NO concentration also increased following transdermal delivery of the nitrosovasodilator, glyceryl trinitrate. Thus, using microdialysis, it is possible to quantify NO production in human skin in vivo and study its modulation during the acute inflammatory response.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::856af75d8806bf525d913652147fcc21Test
https://doi.org/10.1113/expphysiol.1998.sp004126Test -
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المصدر: The FASEB Journal. 27
مصطلحات موضوعية: Tissue oxygenation, Chemistry, Genetics, Human skin, Molecular Biology, Biochemistry, Flux (metabolism), Biotechnology, Biomedical engineering
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::7b19691d0b40c1644aaeda8e09dadd02Test
https://doi.org/10.1096/fasebj.27.1_supplement.901.6Test
