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Ramos TDA, Medeiros CCM, Figueiroa JN, de Carvalho DF, Gusmão TME, Alves JGB. Effects of exergaming on the microcirculation of adolescents with overweight or obesity-a clinical trial efficacy. Appl Physiol Nutr Metab 2023; 48:379-385. [PMID: 36919852 DOI: 10.1139/apnm-2022-0335] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
To assess the effect of exergaming on the microcirculation function of adolescents with overweight or obesity, this non-randomized clinical trial efficacy was conducted with 61 adolescents aged between 10 and 16 years. The intervention group (n = 31) performed exergaming three times per week for 8 weeks. Both groups received guidelines for a healthy diet and staying physically active. Microcirculation was assessed using a laser Doppler flowmetry (LDF) at baseline and after intervention. Primary outcomes derived from LDF assessment included resting flow, maximum flow, maximum/resting flow ratio, area under hyperemia, and post-occlusive reactive hyperemia (PORH). Secondary outcomes were body mass index and systemic blood pressure. Unpaired Student's t test compared intergroup analyses, and paired Student's t test compared intragroup analyses. The significance was set at 5%. Statistical analysis intergroup and intragroup was done by fitting a two-way mixed effects model. Microcirculation was similar between groups. Maximum flow (109.0 ± 38.3 versus 124.6 ± 43.0, P = 0.022), area under hyperemia (1614 ± 472 versus. 1755 ± 461, P = 0.023), and PORH (2.18 ± 0.49 versus 2.01 ± 0.52, P = 0.031) were statistically different after intervention. Body mass index decreased in intervention (24.5 ± 3.8-24.1 ± 4.0 kg/m2, P = 0.002) and control (25.2 ± 3.2-25.1 ± 3.3 kg/m2, P = 0.031) groups. Systolic blood pressure decreased significantly in the intervention group (110 ± 10-106 ± 9 mm Hg; P = 0.041) but not diastolic blood pressure (66.0 ± 7-68.8 ± 8 mm Hg; P = 0.089). Exergaming for 8 weeks led to improvements in the microcirculation function in adolescents with overweighed or obesity. Clinical trials: NTC03532659.
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Affiliation(s)
- Thacira Dantas Almeida Ramos
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Department of Integral Medicine, Postgraduate Program in Integral Medicine, Recife, PE, Brazil.,UniFacisa, Departament of Medicine, Campina Grande, PB, Brazil
| | | | - José Natal Figueiroa
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Department of Integral Medicine, Postgraduate Program in Integral Medicine, Recife, PE, Brazil
| | | | - Tatianne Moura Estrela Gusmão
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Department of Integral Medicine, Postgraduate Program in Integral Medicine, Recife, PE, Brazil.,UniFacisa, Departament of Medicine, Campina Grande, PB, Brazil
| | - João Guilherme Bezerra Alves
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Department of Integral Medicine, Postgraduate Program in Integral Medicine, Recife, PE, Brazil
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Lima NS, Lefferts EC, Clifford PS. Reactive hyperemia augments local heat-induced skin hyperemia. Exp Physiol 2022; 107:383-389. [PMID: 35218593 DOI: 10.1113/ep090071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/11/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? It is valuable to be able to monitor disease or treatment related changes in the microcirculation. Laser doppler flowmetry with local heating allows noninvasive monitoring of the skin microcirculation and its ability to vasodilate. Does reactive hyperemia augment the increase in skin blood flow elicited by local heating? What is the main finding and its importance? The results of this study show that the addition of reactive hyperemia to local heating results in greater vasodilation than heating alone. Thus, reactive hyperemia can augment local heat-induced hyperemia in the skin. ABSTRACT The skin circulation has been proposed as a model of generalized microvascular function which could be monitored noninvasively using laser doppler flowmetry (LDF). The response to heat hyperemia (HH) is commonly used to monitor disease or treatment related changes in microvascular function. We hypothesized that reactive hyperemia would augment the increase in skin blood flow elicited by local heating. Fourteen healthy young adults were subjected to 3 different conditions: reactive hyperemia (RH; skin temperature controlled at 33°C), heat hyperemia (HH; 42°C held for 40 minutes), and HH+RH. Two Peltier-controlled thermomodules with laser LDF probes were placed on the right forearm to continuously monitor skin blood flow. A cuff was placed on the right upper arm to elicit RH by inflation to 220 mmHg for 5 minutes. This procedure was performed with skin temperature at 33°C and again after 40 min of local heating to 42°C. Beat-by-beat mean arterial pressure (MAP) obtained by a photoplethysmographic sensor on the middle finger of the left hand allowed calculation of cutaneous vascular conductance (CVC) as LDF / MAP. Both HH and RH increased LDF (p<0.0001 and p <0.0001, respectively) and CVC (p = 0.0001 and p<0.0001) above baseline values. LDF and CVC values were significantly higher during HH+RH when compared to RH or HH alone (p<0.0001). In summary, HH+RH resulted in greater vasodilation when compared to HH or RH alone. These results indicate that RH can augment local heat-induced hyperemia in the skin. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Natalia S Lima
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Elizabeth C Lefferts
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States.,Department of Kinesiology, Iowa State University, Ames, Iowa, United States
| | - Philip S Clifford
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States
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Fulas OA, Laferrière A, Coderre TJ. Novel Co-crystal of Pentoxifylline and Protocatechuic Acid Relieves Allodynia in Rat Models of Peripheral Neuropathic Pain and CRPS by Alleviating Local Tissue Hypoxia. ACS Chem Neurosci 2021; 12:3855-3863. [PMID: 34610235 DOI: 10.1021/acschemneuro.1c00312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Local tissue ischemic hypoxia is a peripheral process that can be targeted with topical treatment to alleviate pain under chronic pain conditions such as complex regional pain syndrome (CRPS) and peripheral neuropathic pain. We recently reported three novel salts and a co-crystal composed of vasoactive agents and antioxidant nutraceuticals, all of which produced potent topical anti-allodynic effects in the chronic postischemic pain (CPIP) rat model of CRPS. One of the products, pentx-pca, is a co-crystal synthesized from pentoxifylline (pentx) and protocatechuic acid (pca). Pentx-pca exhibited potent topical anti-allodynic effects in CPIP and rats with chronic constriction injury of the sciatic nerve exceeding effects produced individually by pentx and pca. We hypothesized that the anti-allodynic effects of pentx-pca in CPIP rats were due to its impact on local tissue oxygenation and subsequent oxygen-dependent mitochondrial respiration. Percutaneous tissue oxygen saturation (SaO2) measurements taken from the hind paw of the CPIP rats revealed that anti-allodynic doses of topical pentx-pca increased local tissue SaO2. Moreover, assessment of the oxygen-dependent mitochondrial function using a triphenyl tetrazolium chloride assay revealed that mitochondrial dysfunction significantly declined in the plantar muscle collected from CPIP rats topically treated with anti-allodynic doses of pentx-pca as compared to vehicle-treated CPIP rats. Furthermore, time-dependent resolution of plantar muscle mitochondrial dysfunction, that occurred in the CPIP rats at 6-week post procedure, paralleled the loss of the anti-allodynic response to topical treatment with pentx-pca. Our results indicated that pentx-pca produced potent anti-allodynic effects in the CPIP rat model of CRPS by alleviating peripheral tissue ischemia/hypoxia and downstream hypoxia-driven mitochondrial dysfunction.
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Affiliation(s)
- Oli Abate Fulas
- Department of Anesthesia, McGill University, 3655 Promenade Sir William Osler, Montreal, Québec H3G 1Y6, Canada
| | - André Laferrière
- Department of Anesthesia, McGill University, 3655 Promenade Sir William Osler, Montreal, Québec H3G 1Y6, Canada
| | - Terence J. Coderre
- Department of Anesthesia, McGill University, 3655 Promenade Sir William Osler, Montreal, Québec H3G 1Y6, Canada
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Matzkeit N, Schulz L, Schleusser S, Jensen JO, Stang FH, Mailaender P, Krämer R, Kisch T. Cold atmospheric plasma improves cutaneous microcirculation in standardized acute wounds: Results of a controlled, prospective cohort study. Microvasc Res 2021; 138:104211. [PMID: 34144075 DOI: 10.1016/j.mvr.2021.104211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Given the high prevalence of wounds and their challenging treatment, the research of therapies to improve wound healing is of great clinical interest. In addition, the general consequences of developing chronic wounds constitute a large health economic aspect, which underscores the interest in the development of efficient treatment strategies. Direct cold atmospheric plasma (di_CAP) has been shown to have beneficial effects on microcirculation of human tissue (Kisch et al., 2016a). It also affects microbial settlements, which may have supportive effects on wound healing processes (Balzer et al., 2015). To treat these adequately, in our view, the positive effects on wound healing should be objectified by application on standardized wounds. However, wound healing is a complex process, depending on nutrient and oxygen supply by cutaneous blood circulation. In spite of microcirculation has been shown to improve in healthy skin by CAP, a quantification of the effect in a standardized wound model has never been evaluated (Kisch et al., 2016a). Based on this, we hypothesize that CAP also influences the microcirculation in standardized acute wounds in a prospective cohort study. METHODS Microcirculatory data of 20 healthy subjects (14 males, 6 females; mean age 40.85 ± 15.84 years; BMI 26.83 ± 7.27 kg/m2) were recorded continuously at a standardized acute wound after skin transplantation (donor site) at the thigh. Under standardized conditions, microcirculatory measurements were performed using a combined laser Doppler and photospectrometry system. After baseline measurement, CAP was applied by a dielectric barrier discharge (DBD) plasma device for 90 s to the acute wound area. Immediately after the application, cutaneous microcirculation was assessed for 30 min (min) at the same site. RESULTS After CAP application, tissue oxygen saturation immediately increased by 5% (92,66 ± 4,76% vs. Baseline 88,21 ± 6,52%, p < 0,01) in the first 60 s and remained significantly elevated for 4 min. Capillary blood flow increased by 19.3% within the first minute of CAP therapy (220.14 ± 65.91 AU vs. Baseline 184.52 ± 56.77 AU, p < 0.001). The statistically highly significant increase in blood flow continued over the entire measurement time. A maximum value was shown in the blood flow in the 15th minute (232.15 ± 58.90 AU, p < 0.001) according to CAP application. With regard to the output measurement, it represents a percentage increase of 25.8%. The measurement of post-capillary venous filling pressure at a tissue depth of 6-8 mm was 59.39 ± AU 12.94 at baseline measurement. After application, there were no significant changes. CONCLUSION CAP increases cutaneous tissue oxygen saturation and capillary blood flow at the standardized acute wound healing model. These results support recently published data on wound healing after CAP treatment. However, further studies are needed to determine if this treatment can improve the reduced microcirculation in chronic wounds. Moreover, repetitive application protocols have to be compared with a single session treatment approach.
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Affiliation(s)
- Nico Matzkeit
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany.
| | - Lysann Schulz
- Division of Interdisciplinary internal ICU, Medical Department I, University Hospital Leipzig, Germany
| | - Sophie Schleusser
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Jan-Oluf Jensen
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Felix Hagen Stang
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Peter Mailaender
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Robert Krämer
- Department of Plastic, Reconstructive and Aesthetic Surgery, Klinikum Westfalen, Dortmund, Germany
| | - Tobias Kisch
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
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Fredriksson I, Larsson M, Strömberg T. Machine learning for direct oxygen saturation and hemoglobin concentration assessment using diffuse reflectance spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200177SSR. [PMID: 33205635 PMCID: PMC7670094 DOI: 10.1117/1.jbo.25.11.112905] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/28/2020] [Indexed: 05/13/2023]
Abstract
SIGNIFICANCE Diffuse reflectance spectroscopy (DRS) is frequently used to assess oxygen saturation and hemoglobin concentration in living tissue. Methods solving the inverse problem may include time-consuming nonlinear optimization or artificial neural networks (ANN) determining the absorption coefficient one wavelength at a time. AIM To present an ANN-based method that directly outputs the oxygen saturation and the hemoglobin concentration using the shape of the measured spectra as input. APPROACH A probe-based DRS setup with dual source-detector separations in the visible wavelength range was used. ANNs were trained on spectra generated from a three-layer tissue model with oxygen saturation and hemoglobin concentration as target. RESULTS Modeled evaluation data with realistic measurement noise showed an absolute root-mean-square (RMS) deviation of 5.1% units for oxygen saturation estimation. The relative RMS deviation for hemoglobin concentration was 13%. This accuracy is at least twice as good as our previous nonlinear optimization method. On blood-intralipid phantoms, the RMS deviation from the oxygen saturation derived from partial oxygen pressure measurements was 5.3% and 1.6% in two separate measurement series. Results during brachial occlusion showed expected patterns. CONCLUSIONS The presented method, directly assessing oxygen saturation and hemoglobin concentration, is fast, accurate, and robust to noise.
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Affiliation(s)
- Ingemar Fredriksson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
- Perimed AB, Stockholm, Sweden
- Address all correspondence to Ingemar Fredriksson,
| | - Marcus Larsson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Tomas Strömberg
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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6
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Beaumont A, McSorley L, Matthews M, Mooneesawmy K, Little L, Forss JR. Does the application of Opsite ⋄ Flexigrid ⋄ occlude the oxygen saturation readings in healthy individuals using the moorVMS-OXY machine? J Foot Ankle Res 2020; 13:22. [PMID: 32398114 PMCID: PMC7216319 DOI: 10.1186/s13047-020-00391-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/06/2020] [Indexed: 11/10/2022] Open
Abstract
Background A proportion of people who have been diagnosed with peripheral arterial disease and diabetes mellitus will be susceptible to chronic wounds. Oxygen is vital for wound healing, so oxygen measurements should to be taken as predictive values for wound healing in patients. When measuring oxygen at the wound bed, there is potentially a risk of cross-infection if no protective barrier is used; and skin stripping if an adhesive barrier is used on the wound bed. This cross sectional within subject repeated measures pilot study, aims to determine if the application of opsite film, as an infection control measure, in one or two layers, impacts on tissue oxygenation readings obtained when using the MoorVMS-OXY. Methods Mean oxygen saturation percentages were measured from 29 limbs of 18 healthy participants. Oxygen saturation was measured for 20 s and analysed at the first metatarsophalangeal joint using no film, one and two layers using the MoorVMS-OXY. A one-way repeated ANOVA with a Bonferroni post hoc test was performed to test for statistically significant differences between the values of the three parameters and multiple pairwise comparisons was completed. Results Amongst the three layers, there was a statistically significant difference in oxygen saturation between the two layers of Opsite Flexigrid and none; and also between the two layers of Flexigrid and single layer (p < 0.05). It was also established that there was no statistically significant difference between the single layer of Opsite Flexigrid and no Flexigrid layer (p > 0.05). Conclusions The results imply that one layer of Opsite Flexigrid is a suitable protective barrier to use when establishing capillary bed oxygen perfusion with the MoorVMS-OXY. However, the application of two Opsite Flexigrid layers, to prevent skin stripping, decreases the recorded values of oxygen saturation percentages significantly, therefore providing inaccurate results. Indicating that a double layer cannot be used over ulceration sites if measuring oxygen levels at the wound bed.
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Affiliation(s)
- A Beaumont
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK
| | - L McSorley
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK
| | - M Matthews
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK
| | - K Mooneesawmy
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK
| | - L Little
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK
| | - J R Forss
- Centre for Regenerative Medicine and Devices, University of Brighton, 49 Darley Road, Eastbourne, BN20 7UR, UK.
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7
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Jonasson H, Bergstrand S, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Normative data and the influence of age and sex on microcirculatory function in a middle-aged cohort: results from the SCAPIS study. Am J Physiol Heart Circ Physiol 2020; 318:H908-H915. [PMID: 32142355 DOI: 10.1152/ajpheart.00668.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to assess normative values for comprehensive forearm skin microcirculatory function: oxygen saturation, tissue fraction of red blood cells (RBCs), and speed-resolved perfusion. Furthermore, to examine the influence of age and sex on microcirculatory function. Measurements were performed using a noninvasive probe-based system, including diffuse reflectance spectroscopy and laser-Doppler flowmetry, yielding output data in absolute units. The study was conducted within the Swedish CArdioPulmonary BioImage Study (SCAPIS) and included 1,765 men and women aged 50-65 yr from the Linköping general population. Normative values are given at baseline, at the end of a 5-min occlusion of the brachial artery and during hyperemia after occlusion release. We found a consistent age distribution, in which the oldest individuals had the lowest peak oxygen saturation (P < 0.001) and the highest baseline low-speed perfusion (P < 0.001). Women had higher peak oxygen saturation (P < 0.001), lower RBC tissue fraction, in general (P < 0.001), lower baseline perfusion in all speed regions (P = 0.01), and lower peak high-speed perfusion at hyperemia (P < 0.001). The normative data can be used as reference values in future studies of disease-specific populations. The results show that age and sex are important aspects to consider in studies of microvascular function. Women and younger age were factors associated with higher peak oxygen saturation after ischemia. This is a novel parameter that reflects overall microcirculatory function associated with vascular dilation capacity.NEW & NOTEWORTHY This study expands experimental microcirculatory research to clinical use by providing normative values on microcirculatory function in a large population-based cohort. Women and younger age were factors associated with higher peak oxygen saturation after ischemia, which implies that age and sex are important aspects to consider in studies of microvascular function. This study is the first step toward using microcirculatory assessment as a tool to improve diagnosis, prognosis, and treatment in disease-specific populations.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.,Perimed AB, Järfälla, Stockholm, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Mekić S, Hamer M, Wigmann C, Gunn D, Kayser M, Jacobs L, Schikowski T, Nijsten T, Pardo L. Epidemiology and determinants of facial telangiectasia: a cross‐sectional study. J Eur Acad Dermatol Venereol 2020; 34:821-826. [DOI: 10.1111/jdv.15996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 09/04/2019] [Indexed: 01/01/2023]
Affiliation(s)
- S. Mekić
- Department of Dermatology Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
| | - M.A. Hamer
- Department of Dermatology Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
| | - C. Wigmann
- IUF – Leibniz Research Institute for Environmental Medicine Düsseldorf Germany
| | - D.A. Gunn
- Unilever Research and Development Colworth Science Park Sharnbrook UK
| | - M. Kayser
- Department of Genetic Identification Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
| | - L.C. Jacobs
- Department of Dermatology Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
| | - T. Schikowski
- IUF – Leibniz Research Institute for Environmental Medicine Düsseldorf Germany
| | - T. Nijsten
- Department of Dermatology Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
| | - L.M. Pardo
- Department of Dermatology Erasmus MC University Medical Center Rotterdam Rotterdam The Netherlands
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Wang G, Jia S, Liu M, Song X, Li H, Chang X, Zhang W. Impact of local thermal stimulation on the correlation between oxygen saturation and speed-resolved blood perfusion. Sci Rep 2020; 10:183. [PMID: 31932611 PMCID: PMC6957488 DOI: 10.1038/s41598-019-57067-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/18/2019] [Indexed: 11/23/2022] Open
Abstract
The physiologically important relationship between oxygen saturation and blood flow is not entirely understood, particularly with regard to the multiple velocity components of flow and temperature. While our previous studies used classic laser Doppler flowmetry combined with an enhanced perfusion probe to assess local blood flow following thermal stimulation, oxygen saturation signals were not assessed. Thus, the current study used multiscale entropy (MSE) and multiscale fuzzy entropy (MFE) to measure the complexity of oxygen saturation signals following thermal stimulation in healthy subjects. The results indicate that thermal stimulation increases oxygen saturation and affects the measured signal complexity in a temperature-dependent fashion. Furthermore, stimulus temperature not only affects the correlation between speed-resolved blood perfusion and oxygen saturation, but also the correlation between the complexity area indices (CAI) of the two signals. These results reflect the complexity of local regulation and adaptation processes in response to stimuli at different temperatures.
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Affiliation(s)
- Guangjun Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Shuyong Jia
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Mi Liu
- Acupuncture and Tuina School, Hunan University of Chinese Medicine, Changsha, China
| | - Xiaojing Song
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hongyan Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaorong Chang
- Acupuncture and Tuina School, Hunan University of Chinese Medicine, Changsha, China.
| | - Weibo Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China.
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10
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Corliss BA, Mathews C, Doty R, Rohde G, Peirce SM. Methods to label, image, and analyze the complex structural architectures of microvascular networks. Microcirculation 2019; 26:e12520. [PMID: 30548558 PMCID: PMC6561846 DOI: 10.1111/micc.12520] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/31/2018] [Accepted: 11/26/2018] [Indexed: 12/30/2022]
Abstract
Microvascular networks play key roles in oxygen transport and nutrient delivery to meet the varied and dynamic metabolic needs of different tissues throughout the body, and their spatial architectures of interconnected blood vessel segments are highly complex. Moreover, functional adaptations of the microcirculation enabled by structural adaptations in microvascular network architecture are required for development, wound healing, and often invoked in disease conditions, including the top eight causes of death in the Unites States. Effective characterization of microvascular network architectures is not only limited by the available techniques to visualize microvessels but also reliant on the available quantitative metrics that accurately delineate between spatial patterns in altered networks. In this review, we survey models used for studying the microvasculature, methods to label and image microvessels, and the metrics and software packages used to quantify microvascular networks. These programs have provided researchers with invaluable tools, yet we estimate that they have collectively attained low adoption rates, possibly due to limitations with basic validation, segmentation performance, and nonstandard sets of quantification metrics. To address these existing constraints, we discuss opportunities to improve effectiveness, rigor, and reproducibility of microvascular network quantification to better serve the current and future needs of microvascular research.
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Affiliation(s)
- Bruce A. Corliss
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginia
| | - Corbin Mathews
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginia
| | - Richard Doty
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginia
| | - Gustavo Rohde
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginia
| | - Shayn M. Peirce
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginia
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Chen H, Liu G, Zhang S, Shen S, Luo Y, Li J, Roberts CJ, Sun M, Xu RX. Fundus-simulating phantom for calibration of retinal vessel oximetry devices. APPLIED OPTICS 2019; 58:3877-3885. [PMID: 31158206 DOI: 10.1364/ao.58.003877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
Retinal vessel oxygen supply is important for retinal tissue metabolism. Commonly used retinal vessel oximetry devices are based on dual-wavelength spectral measurement of oxyhemoglobin and deoxyhemoglobin. However, there is no traceable standard for reliable calibration of these devices. In this study, we developed a fundus-simulating phantom that closely mimicked the optical properties of human fundus tissues. Microchannels of precisely controlled topological structures were produced by soft lithography to simulate the retinal vasculature. Optical properties of the phantom were adjusted by adding scattering and absorption agents to simulate different concentrations of fundus pigments. The developed phantom was used to calibrate the linear correlation between oxygen saturation (SO2) level and optical density ratio in a dual-wavelength oximetry device. The obtained calibration factors were used to calculate the retinal vessel SO2 in both eyes of five volunteers aged between 24 and 27 years old. The test results showed that the mean arterial and venous SO2 levels after phantom calibration were coincident with those after empirical value calibration, indicating the potential clinical utility of the produced phantom as a calibration standard.
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12
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Chipperfield AJ, Thanaj M, Scorletti E, Byrne CD, Clough GF. Multi-domain analysis of microvascular flow motion dynamics in NAFLD. Microcirculation 2019; 26:e12538. [PMID: 30803094 DOI: 10.1111/micc.12538] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/22/2019] [Accepted: 02/20/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To determine whether analysis of microvascular network perfusion using complexity-based methods can discriminate between groups of individuals at an increased risk of developing CVD. METHODS Data were obtained from laser Doppler recordings of skin blood flux at the forearm in 50 participants with non-alcoholic fatty liver disease grouped for absence (n = 28) or presence (n = 14) of type 2 diabetes and use of calcium channel blocker medication (n = 8). Power spectral density was evaluated and Lempel-Ziv complexity determined to quantify signal information content at single and multiple time-scales to account for the different processes modulating network perfusion. RESULTS Complexity was associated with dilatory capacity and respiration and negatively with baseline blood flux and cardiac band power. The relationship between the modulators of flowmotion and complexity of blood flux is shown to change with time-scale improving discrimination between groups. Multiscale Lempel-Ziv achieved best classification accuracy of 86.1%. CONCLUSIONS Time and frequency domain measures alone are insufficient to discriminate between groups. As cardiovascular disease risk increases, the degree of complexity of the blood flux signal reduces, indicative of a reduced temporal activity and heterogeneous distribution of blood flow within the microvascular network sampled. Complexity-based methods, particularly multiscale variants, are shown to have good discriminatory capabilities.
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Affiliation(s)
- Andrew J Chipperfield
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Marjola Thanaj
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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13
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Thanaj M, Chipperfield AJ, Clough GF. Analysis of microvascular blood flow and oxygenation: Discrimination between two haemodynamic steady states using nonlinear measures and multiscale analysis. Comput Biol Med 2018; 102:157-167. [DOI: 10.1016/j.compbiomed.2018.09.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/07/2018] [Accepted: 09/24/2018] [Indexed: 11/16/2022]
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14
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Davies T, Gilbert-Kawai E, Wythe S, Meale P, Mythen M, Levett D, Mitchell K, Grocott M, Clough G, Martin D. Sustained vasomotor control of skin microcirculation in Sherpas versus altitude-naive lowlanders: Experimental evidence from Xtreme Everest 2. Exp Physiol 2018; 103:1494-1504. [PMID: 30182473 DOI: 10.1113/ep087236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/21/2018] [Indexed: 12/20/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do Sherpa highlanders, when exposed to graded hypobaric hypoxia, exhibit enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders? What is the main finding and its importance? Sherpas, when exposed to hypobaric hypoxia at high altitude, demonstrated superior preservation of their peripheral microcirculatory perfusion, a greater oxygen unloading rate and sustained microvascular reactivity with enhanced vasomotion, when compared with altitude-naive lowlanders. These differences have not been reported previously and may improve our understanding of the multifactorial responses to sustained environmental hypoxia. ABSTRACT Enhanced oxygen delivery, consequent to an increased microvascular perfusion, has been postulated to play a key role in the physiological adaptation of Tibetan highlanders to the hypobaric hypoxia encountered at high altitude. We tested the hypothesis that Sherpas, when exposed to graded hypobaric hypoxia, demonstrate enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders. Eighty-three lowlanders [39 men and 44 women, 38.8 (13.1) years old; mean (SD)] and 61 Sherpas [28 men and 33 women, 27.9 (6.9) years old] were studied on ascent to Everest Base Camp over 11 days. Skin blood flux and tissue oxygen saturation were measured simultaneously using combined laser Doppler fluximetry and white light spectroscopy at baseline, 3500 and 5300 m. In both cohorts, ascent resulted in a decline in the sympathetically mediated microvascular constrictor response (P < 0.001), which was more marked in lowlanders than in Sherpas (P < 0.001). The microvascular dilator response evaluated by postocclusive reactive hyperaemia was significantly greater in Sherpas than in lowlanders at all sites (P < 0.002). Spectral analysis of the blood flux signals revealed enhanced myogenic (vasomotion) activity in Sherpas, which was unaffected by ascent to 5300 m. Although skin tissue oxygenation was lower in Sherpas than in lowlanders, the oxygen unloading rate was faster, and deoxyhaemoglobin levels higher, at all altitudes. Together, these data suggest that Sherpas, when exposed to hypobaric hypoxia, demonstrated superior preservation of peripheral microcirculatory perfusion compared with altitude-naive lowlanders. The physiological differences in local microvasculature vasomotor and neurovascular control may play a key role in Sherpa adaptation to high-altitude hypobaric hypoxia by sustaining local perfusion and tissue oxygenation.
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Affiliation(s)
- Thomas Davies
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Edward Gilbert-Kawai
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Stephen Wythe
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Paula Meale
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Monty Mythen
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Denny Levett
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Faculty of Medicine (CES) and Institute for Life Science, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,Centre for Human Integrative Physiology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Kay Mitchell
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Michael Grocott
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Faculty of Medicine (CES) and Institute for Life Science, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,Centre for Human Integrative Physiology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Geraldine Clough
- Institute of Developmental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Daniel Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Critical Care Unit, Royal Free Hospital, London, UK
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- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
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Liu G, Wu Q, Dwivedi P, Hu C, Zhu Z, Shen S, Chu J, Zhao G, Si T, Xu R. Hemoglobin-Laden Microcapsules for Simulating Oxygen Dynamics of Biological Tissue. ACS Biomater Sci Eng 2018; 4:3177-3184. [DOI: 10.1021/acsbiomaterials.8b00830] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Guangli Liu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Qiang Wu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Pankaj Dwivedi
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Chuanzhen Hu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Zhiqiang Zhu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Shuwei Shen
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Jiaru Chu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Gang Zhao
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Ting Si
- Department of Modern Mechanics, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
| | - Ronald Xu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China
- Department of Biomedical Engineering, The Ohio State University, 1080 Carmack Road, Columbus, Ohio 43210, United States
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16
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Jing Y, Bai F, Chen H, Dong H. Using Laser Doppler Imaging and Monitoring to Analyze Spinal Cord Microcirculation in Rat. J Vis Exp 2018. [PMID: 29912181 DOI: 10.3791/56243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Laser Doppler flowmetry (LDF) is a noninvasive method for blood flow (BF) measurement, which makes it preferable for measuring microcirculatory alterations of the spinal cord. In this article, our goal was to use both Laser Doppler imaging and monitoring to analyze the change of BF after spinal cord injury. Both the laser Doppler image scanner and the probe/monitor were being employed to obtain each readout. The data of LDPI provided a local distribution of BF, which gave an overview of perfusion around the injury site and made it accessible for comparative analysis of BF among different locations. By intensely measuring the probing area over a period of time, a combined probe was used to simultaneously measure the BF and oxygen saturation of the spinal cord, showing overall spinal cord perfusion and oxygen supply. LDF itself has a few limitations, such as relative flux, sensitivity to movement, and biological zero signal. However, the technology has been applied in clinical and experimental study due to its simple setup and rapid measurement of BF.
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Affiliation(s)
- Yingli Jing
- China Rehabilitation Research Center; Institute of Rehabilitation Science of China; Center of Neural Injury and Repair, Beijing Institute for Brain Disorders; Beijing Key Laboratory of Neural Injury and Rehabilitation
| | - Fan Bai
- China Rehabilitation Research Center; Institute of Rehabilitation Science of China; Center of Neural Injury and Repair, Beijing Institute for Brain Disorders; Beijing Key Laboratory of Neural Injury and Rehabilitation
| | - Hui Chen
- China Rehabilitation Research Center; Institute of Rehabilitation Science of China; Center of Neural Injury and Repair, Beijing Institute for Brain Disorders; Beijing Key Laboratory of Neural Injury and Rehabilitation
| | - Hao Dong
- China Rehabilitation Research Center; Institute of Rehabilitation Science of China; Center of Neural Injury and Repair, Beijing Institute for Brain Disorders; Beijing Key Laboratory of Neural Injury and Rehabilitation;
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17
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Parshakov A, Zubareva N, Podtaev S, Frick P. Detection of Endothelial Dysfunction Using Skin Temperature Oscillations Analysis During Local Heating in Patients With Peripheral Arterial Disease. Microcirculation 2018; 23:406-15. [PMID: 27177504 DOI: 10.1111/micc.12283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 04/18/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The purpose of this study was to examine correlations between laboratory markers of ED and the degree of endothelium-dependent vasodilation using WAST during a local heating test in patients with PAD. MATERIALS AND METHODS The study population consisted of 17 healthy subjects and 38 patients with PAD. The ST on the plantar surface of the first toe was measured during the test, and the inverse wavelet transform was applied to reconstruct the ST signals in three frequency bands corresponding to myogenic, neurogenic, and endothelial mechanisms of vascular tone regulation. RESULTS In healthy subjects, a local increase in temperature of up to 42°C caused a greater than threefold increase in the amplitudes of foot ST oscillations. Among patients with PAD, the response to the test was much weaker in all frequency ranges. The level of vasodilation dysfunction correlated with the level of artery stenosis in the lower extremities and with laboratory markers of ED (endothelin, homocysteine, and von Willebrand factor). CONCLUSION WAST can be considered as a low cost, portable, and easy to use technique for the noninvasive assessment of ED.
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Affiliation(s)
- Aleksey Parshakov
- Perm State Medical University, Perm, Russia.,Institute of Continuous Media Mechanics, Perm, Russia
| | - Nadezhda Zubareva
- Perm State Medical University, Perm, Russia.,Institute of Continuous Media Mechanics, Perm, Russia
| | | | - Peter Frick
- Institute of Continuous Media Mechanics, Perm, Russia
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18
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Clough GF, Kuliga KZ, Chipperfield AJ. Flow motion dynamics of microvascular blood flow and oxygenation: Evidence of adaptive changes in obesity and type 2 diabetes mellitus/insulin resistance. Microcirculation 2018; 24. [PMID: 27809397 DOI: 10.1111/micc.12331] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 10/31/2016] [Indexed: 11/29/2022]
Abstract
An altered spatial heterogeneity and temporal stability of network perfusion can give rise to a limited adaptive ability to meet metabolic demands. Derangement of local flow motion activity is associated with reduced microvascular blood flow and tissue oxygenation, and it has been suggested that changes in flow motion activity may provide an early indicator of declining, endothelial, neurogenic, and myogenic regulatory mechanisms and signal the onset and progression of microvascular pathophysiology. This short conference review article explores some of the evidence for altered flow motion dynamics of blood flux signals acquired using laser Doppler fluximetry in the skin in individuals at risk of developing or with cardiometabolic disease.
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Affiliation(s)
| | - Katarzyna Z Kuliga
- Faculty of Medicine, University of Southampton, Southampton, UK.,Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - Andrew J Chipperfield
- Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
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19
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Zeller-Plumhoff B, Roose T, Clough GF, Schneider P. Image-based modelling of skeletal muscle oxygenation. J R Soc Interface 2017; 14:rsif.2016.0992. [PMID: 28202595 DOI: 10.1098/rsif.2016.0992] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/25/2017] [Indexed: 12/12/2022] Open
Abstract
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. biological in vivo and in vitro experiments, 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 microvasculature in vivo and ex 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.
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Affiliation(s)
- B Zeller-Plumhoff
- Helmholtz-Zentrum für Material- und Küstenforschung, Geesthacht, Germany .,Bioengineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - T Roose
- Bioengineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - G F Clough
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - P Schneider
- Bioengineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
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20
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Bergstrand S, Morales MA, Coppini G, Larsson M, Strömberg T. The relationship between forearm skin speed-resolved perfusion and oxygen saturation, and finger arterial pulsation amplitudes, as indirect measures of endothelial function. Microcirculation 2017; 25. [PMID: 29044805 DOI: 10.1111/micc.12422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 10/11/2017] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Endothelial function is important for regulating peripheral blood flow to meet varying metabolic demands and can be measured indirectly during vascular provocations. In this study, we compared the PAT finger response (EndoPAT) after a 5-minutes arterial occlusion to that from forearm skin comprehensive microcirculation analysis (EPOS). METHODS Measurements in 16 subjects with varying cardiovascular risk factors were carried out concurrently with both methods during arterial occlusion, while forearm skin was also evaluated during local heating. RESULTS Peak values for EPOS skin Perfconv and speed-resolved total perfusion after the release of the occlusion were significantly correlated to the EndoPAT RHI (ρ = .68, P = .007 and ρ = .60, P = .025, respectively), mainly due to high-speed blood flow. During local heating, EPOS skin oxygen saturation, SO2, was significantly correlated to RHI (ρ = .62, P = .043). This indicates that SO2 may have diagnostic value regarding endothelial function. CONCLUSIONS We have demonstrated for the first time a significant relationship between forearm skin microcirculatory perfusion and oxygen saturation and finger PAT. Both local heating and reactive hyperemia are useful skin provocations. Further studies are needed to understand the precise regulation mechanisms of blood flow and oxygenation during these tests.
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Affiliation(s)
- Sara Bergstrand
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | | | | | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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21
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Russell RD, Hu D, Greenaway T, Blackwood SJ, Dwyer RM, Sharman JE, Jones G, Squibb KA, Brown AA, Otahal P, Boman M, Al-Aubaidy H, Premilovac D, Roberts CK, Hitchins S, Richards SM, Rattigan S, Keske MA. Skeletal Muscle Microvascular-Linked Improvements in Glycemic Control From Resistance Training in Individuals With Type 2 Diabetes. Diabetes Care 2017; 40:1256-1263. [PMID: 28687542 DOI: 10.2337/dc16-2750] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 06/16/2017] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Insulin increases glucose disposal in part by enhancing microvascular blood flow (MBF) and substrate delivery to myocytes. Insulin's microvascular action is impaired with insulin resistance and type 2 diabetes. Resistance training (RT) improves glycemic control and insulin sensitivity, but whether this improvement is linked to augmented skeletal muscle microvascular responses in type 2 diabetes is unknown. RESEARCH DESIGN AND METHODS Seventeen (11 male and 6 female; 52 ± 2 years old) sedentary patients with type 2 diabetes underwent 6 weeks of whole-body RT. Before and after RT, participants who fasted overnight had clinical chemistries measured (lipids, glucose, HbA1c, insulin, and advanced glycation end products) and underwent an oral glucose challenge (OGC) (50 g × 2 h). Forearm muscle MBF was assessed by contrast-enhanced ultrasound, skin MBF by laser Doppler flowmetry, and brachial artery flow by Doppler ultrasound at baseline and 60 min post-OGC. A whole-body DEXA scan before and after RT assessed body composition. RESULTS After RT, muscle MBF response to the OGC increased, while skin microvascular responses were unchanged. These microvascular adaptations were accompanied by improved glycemic control (fasting blood glucose, HbA1c, and glucose area under the curve [AUC] during OGC) and increased lean body mass and reductions in fasting plasma triglyceride, total cholesterol, advanced glycation end products, and total body fat. Changes in muscle MBF response after RT significantly correlated with reductions in fasting blood glucose, HbA1c, and OGC AUC with adjustment for age, sex, % body fat, and % lean mass. CONCLUSIONS RT improves OGC-stimulated muscle MBF and glycemic control concomitantly, suggesting that MBF plays a role in improved glycemic control from RT.
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Affiliation(s)
- Ryan D Russell
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,Department of Health and Human Performance, College of Health Services, University of Texas Rio Grande Valley, Brownsville, TX
| | - Donghua Hu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Timothy Greenaway
- Royal Hobart Hospital, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Sarah J Blackwood
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Renee M Dwyer
- School of Medicine, University of Tasmania, Hobart, Australia
| | - James E Sharman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Graeme Jones
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kathryn A Squibb
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Aascha A Brown
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Petr Otahal
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Meg Boman
- Royal Hobart Hospital, Hobart, Australia
| | | | - Dino Premilovac
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Christian K Roberts
- Geriatric Research, Education and Clinical Center (GRECC), VA Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Samuel Hitchins
- School of Medicine, University of Tasmania, Hobart, Australia
| | | | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Michelle A Keske
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia .,Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
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22
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23
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Blackwood SJ, Dwyer RM, Bradley EA, Keske MA, Richards SM, Rattigan S. Determination of Skeletal Muscle Microvascular Flowmotion with Contrast-Enhanced Ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2013-2023. [PMID: 28655467 DOI: 10.1016/j.ultrasmedbio.2017.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/29/2017] [Accepted: 05/08/2017] [Indexed: 06/07/2023]
Abstract
Most methods of assessing flowmotion (rhythmic oscillation of blood flow through tissue) are limited to small sections of tissue and are invasive in tissues other than skin. To overcome these limitations, we adapted the contrast-enhanced ultrasound (CEUS) technique to assess microvascular flowmotion throughout a large region of tissue, in a non-invasive manner and in real time. Skeletal muscle flowmotion was assessed in anaesthetised Sprague Dawley rats, using CEUS and laser Doppler flowmetry (LDF) for comparison. Wavelet transformation of CEUS and LDF data was used to quantify flowmotion. The α-adrenoceptor antagonist phentolamine was infused to predictably blunt the neurogenic component of flowmotion. Both techniques identified similar flowmotion patterns, validating the use of CEUS to assess flowmotion. This study demonstrates for the first time that the novel technique of CEUS can be adapted for determination of skeletal muscle flowmotion in large regions of skeletal muscle.
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Affiliation(s)
- Sarah J Blackwood
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
| | - Renee M Dwyer
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Eloise A Bradley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Michelle A Keske
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | | | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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24
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Strömberg T, Sjöberg F, Bergstrand S. Temporal and spatiotemporal variability in comprehensive forearm skin microcirculation assessment during occlusion protocols. Microvasc Res 2017; 113:50-55. [PMID: 28455225 DOI: 10.1016/j.mvr.2017.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
Forearm skin hyperemia during release after brachial occlusion has been proposed for evaluating peripheral arterial disease and endothelial dysfunction. We used a novel fiberoptic system integrating Laser Doppler Flowmetry and Diffuse Reflectance Spectroscopy for a comprehensive pointwise model based microcirculation characterization. The aim was to evaluate and compare the temporal and the spatiotemporal variabilities in forearm skin microcirculation parameters (speed resolved perfusion; low speed <1mm/s, PerfSR, <1; mid-speed 1-10mm/s, high speed >10mm/s, and total perfusion (PerfSR, tot); the concentration and oxygenation of red blood cells, CRBC and SO2). Ten healthy subjects underwent arterial and venous forearm occlusions (AO, VO), repeated within one week. The repeatability was calculated as the coefficient of variation (CV) and the agreement as the intra-class correlation coefficient (ICC). The temporal CVs for conventional perfusion, Perfconv, PerfSR, tot, CRBC and SO2 were 14%, 12%, 9% and 9%, respectively, while the ICC were >0.75 (excellent). The perfusion measures generally had a higher spatiotemporal than temporal variability, which was not the case for SO2 and CRBC. The corresponding spatiotemporal CVs were 33%, 32%, 18% and 15%, respectively. During VO, CRBC had a CV<35% and ICC>0.40 (fair-good), and after release this was the case for CRBC (AO and VO), SO2 (VO) and PerfSR, <1 (VO). In conclusion, the skin microcirculation parameters showed excellent temporal repeatability, while the spatiotemporal repeatability especially for perfusion was poorer. The parameters with acceptable repeatability and fair-good agreement were: CRBC during and after release of VO, the PerfSR, <1 after release of VO, the SO2 and the CRBC after release of AO. However, the value of these parameters in discriminating endothelial function remains to be studied.
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Affiliation(s)
- Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
| | - Folke Sjöberg
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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25
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Wenner MM, Sebzda KN, Kuczmarski AV, Pohlig RT, Edwards DG. ET B receptor contribution to vascular dysfunction in postmenopausal women. Am J Physiol Regul Integr Comp Physiol 2017; 313:R51-R57. [PMID: 28438762 DOI: 10.1152/ajpregu.00410.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/27/2017] [Accepted: 04/20/2017] [Indexed: 01/05/2023]
Abstract
Endothelin-1 (ET-1) contributes to age-related endothelial dysfunction in men via the ETA receptor. However, there are sex differences in the ET-1 system, and ETB receptors are modulated by sex hormones. The purpose of this study was to test the hypothesis that ETB receptors contribute to impaired vasodilatory function in postmenopausal women (PMW). We measured flow-mediated dilation (FMD) using ultrasound, and cutaneous nitric oxide-mediated vasodilation during local heating (42°C) via laser Doppler flowmetry in 18 young women (YW; 22 ± 1 yr) and 16 PMW (56 ± 1 yr). Cutaneous microdialysis perfusions of lactated Ringer (control), an ETB receptor antagonist (BQ-788, 300 nM), and an ETA receptor antagonist (BQ-123, 500 nM), were done through separate fibers, followed by perfusions of sodium nitroprusside (28 mM) and local heating to 43°C (max). Cutaneous vascular conductance (CVC) was calculated as cutaneous blood flow/mean arterial pressure and expressed as a percent of maximal dilation. FMD (YW: 7.5 ± 0.5 vs. PMW: 5.6 ± 0.6%) and cutaneous vasodilation (YW: 93 ± 2 vs. PMW: 83 ± 4%CVCmax) were lower in PMW (both P < 0.05). Blockade of ETB receptors decreased cutaneous vasodilation in YW (87 ± 2%CVCmax; P < 0.05 vs. control) but increased vasodilation in PMW (93 ± 1%CVCmax; P < 0.05 vs. control). ETA receptor blockade had minimal effect in YW (92 ± 1%CVCmax) but increased cutaneous vasodilation in PMW (91 ± 2%CVCmax; P < 0.05 vs. control). In conclusion, ETB receptors mediate vasodilation in YW, but this effect is lost after menopause. Impaired vasodilatory function in PMW is due in part to a loss of ETB-mediated dilation.
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Affiliation(s)
- Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Kelly N Sebzda
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Andrew V Kuczmarski
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Ryan T Pohlig
- Biostatistics Core Facility, College of Health Sciences, University of Delaware, Newark, Delaware
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
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26
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Kuliga KZ, Gush R, Clough GF, Chipperfield AJ. Time-dependent Behavior of Microvascular Blood Flow and Oxygenation: a Predictor of Functional Outcomes. IEEE Trans Biomed Eng 2017; 65:1049-1056. [DOI: 10.1109/tbme.2017.2737328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Cracowski JL, Roustit M. Current Methods to Assess Human Cutaneous Blood Flow: An Updated Focus on Laser-Based-Techniques. Microcirculation 2016; 23:337-44. [DOI: 10.1111/micc.12257] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/20/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Jean-Luc Cracowski
- Université Grenoble Alpes; Grenoble France
- INSERM; Grenoble France
- Clinical Pharmacology Unit; INSERM CIC1406; Grenoble University Hospital; Grenoble France
| | - Matthieu Roustit
- Université Grenoble Alpes; Grenoble France
- INSERM; Grenoble France
- Clinical Pharmacology Unit; INSERM CIC1406; Grenoble University Hospital; Grenoble France
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28
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Wenner MM, Taylor HS, Stachenfeld NS. Peripheral Microvascular Vasodilatory Response to Estradiol and Genistein in Women with Insulin Resistance. Microcirculation 2016; 22:391-9. [PMID: 25996650 DOI: 10.1111/micc.12208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 05/14/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE E2 enhances vasodilation in healthy women, but vascular effects of the phytoestrogen GEN are still under investigation. IR compromises microvascular function. We therefore examined the interaction of E2 , GEN, and IR on microvascular vasodilatory responsiveness. METHODS We hypothesized that E2 and GEN increase microvascular vasodilation in healthy women (control, n = 8, 23 ± 2 year, BMI: 25.9 ± 2.9 kg/m2) but not in women with IR (n = 7, 20 ± 1 year, BMI: 27.3 ± 3.0 kg/m2). We used the cutaneous circulation as a model of microvascular vasodilatory function. We determined CVC with laser Doppler flowmetry and beat-to-beat blood pressure during local cutaneous heating (42 °C) with E2 or GEN microdialysis perfusions. Because heat-induced vasodilation is primarily an NO-mediated response, we examined microvascular vasodilation with and without L-NMMA. RESULTS In C, E2 enhanced CVC (94.4 ± 2.6% vs. saline 81.6 ± 4.2% CVCmax , p < 0.05), which was reversed with L-NMMA (80.9 ± 7.8% CVCmax , p < 0.05), but GEN did not affect vasodilation. Neither E2 nor GEN altered CVC in IR, although L-NMMA attenuated CVC during GEN. CONCLUSIONS Our study does not support improved microvascular responsiveness during GEN exposure in healthy young women, and demonstrates that neither E2 nor GEN improves microvascular vasodilatory responsiveness in women with IR.
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Affiliation(s)
- Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, USA
| | - Hugh S Taylor
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, USA
| | - Nina S Stachenfeld
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, USA.,The John B. Pierce Laboratory, New Haven, Connecticut.,Yale School of Public Health, New Haven, Connecticut, USA
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29
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Kisch T, Helmke A, Schleusser S, Song J, Liodaki E, Stang FH, Mailaender P, Kraemer R. Improvement of cutaneous microcirculation by cold atmospheric plasma (CAP): Results of a controlled, prospective cohort study. Microvasc Res 2015; 104:55-62. [PMID: 26655582 DOI: 10.1016/j.mvr.2015.12.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/02/2015] [Accepted: 12/03/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Cold atmospheric plasma (CAP) has proven its benefits in the reduction of various bacteria and fungi in both in vitro and in vivo studies. Moreover, CAP generated by dielectric barrier discharge (DBD) promoted wound healing in vivo. Charged particles, chemically reactive species (such as O3, OH, H2O2, O, NxOy), ultraviolet radiation (UV-A and UV-B), strong oscillating electric fields as well as weak electric currents are produced by DBD operated in air. However, wound healing is a complex process, depending on nutrient and oxygen supply via cutaneous blood circulation. Therefore, this study examined the effects of CAP on cutaneous microcirculation in a prospective cohort setting. HYPOTHESIS Cold atmospheric plasma application enhances cutaneous microcirculation. METHODS Microcirculatory data of 20 healthy subjects (11 males, 9 females; mean age 35.2 ± 13.8 years; BMI 24.3 ± 3.1 kg/m(2)) were recorded continuously at a defined skin area at the radial forearm. Under standardized conditions, microcirculatory measurements were performed using a combined laser Doppler and photospectrometry system. After baseline measurement, CAP was applied by a DBD plasma device for 90 s to the same defined skin area of 22.5 cm(2). Immediately after the application cutaneous microcirculation was assessed for 30 min at the same site. RESULTS After CAP application, tissue oxygen saturation immediately increased by 24% (63.8 ± 13.8% from 51.4 ± 13.2% at baseline, p<0.001) and stayed significantly elevated for 8 min. Cutaneous blood flow increased by 73% (41.0 ± 31.2 AU from 23.7 ± 20.8 AU at baseline, p<0.001) and remained upregulated for 11 min. Furthermore, cutaneous blood flow showed two peaks at 14 (29.8 ± 25.0 AU, p=0.049) and 19 min (29.8 ± 22.6 AU, p=0.048) after treatment. Postcapillary venous filling pressure continuously increased, but showed no significant change vs. baseline in the non-specific BMI group. Subgroup analysis revealed that tissue oxygen saturation, postcapillary venous filling pressure and blood flow increased more in case of a lower BMI. CONCLUSION CAP increases cutaneous tissue oxygen saturation and capillary blood flow at the radial forearm of healthy volunteers. These results support recently published data on wound healing after CAP treatment. However, further studies are needed to determine if this treatment can improve the reduced microcirculation in diabetic foot ulcers. Moreover, repetitive application protocols have to be compared with a single session treatment approach.
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Affiliation(s)
- Tobias Kisch
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany.
| | - Andreas Helmke
- Application Center for Plasma and Photonic APP, Fraunhofer Institute for Surface Engineering and Thin Films IST, Göttingen, Germany
| | - Sophie Schleusser
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Jungin Song
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Eirini Liodaki
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Felix Hagen Stang
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Peter Mailaender
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
| | - Robert Kraemer
- Department of Plastic Surgery, Hand Surgery, Burn Unit, University Hospital of Schleswig-Holstein, Campus Lübeck, University of Lübeck, Lübeck, Germany
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Wu GA, Bogie KM. Effects of conventional and alternating cushion weight-shifting in persons with spinal cord injury. ACTA ACUST UNITED AC 2015; 51:1265-76. [PMID: 25629607 DOI: 10.1682/jrrd.2014.01.0009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 07/03/2014] [Indexed: 11/05/2022]
Abstract
A repeated-measures study of 13 adult full-time wheelchair users with spinal cord injury (SCI) was carried out to determine whether alternating-pressure air cushion (APAC) use compared with independent pressure relief (IPR) provides reliable, effective pressure relief for individuals with SCI. Bilateral mean ischial interface pressure (IP), transcutaneous oxygen tension (TcPO2), and unilateral laser Doppler blood flow were evaluated. Blood flow component contributions were determined using short-time Fourier transform (STFT)-based spectral analysis. IPR assessment was carried out at recruitment. Study participants then used an APAC for 2 wk every 3 mo for 18 mo. IPR weight-shifting decreased mean ischial IP (p < 0.05) and increased mean TcPO2 (p < 0.05). All variables rapidly returned to preintervention levels following weight-shifting except for the cardiac component of blood flow. APAC-induced weight-shifting decreased mean ischial IP (p < 0.05). Mean TcPO2 increased and was higher than for IPR. STFT analysis indicated that quiet sitting following APAC-induced weight-shifting produced a higher neurogenic component of blood flow than following IPR (p = 0.02). Thus, IPR positively affects multiple aspects of tissue health but produces transient improvements and must be repeated regularly. APAC activation dynamically and continuously alters IP distribution with more sustained positive tissue health effects.
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Affiliation(s)
- Gary A Wu
- Department of Physical Medicine and Rehabilitation, MetroHealth Medical Center, Cleveland, OH; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH; and Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH
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31
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Jonasson H, Fredriksson I, Pettersson A, Larsson M, Strömberg T. Oxygen saturation, red blood cell tissue fraction and speed resolved perfusion - A new optical method for microcirculatory assessment. Microvasc Res 2015; 102:70-7. [PMID: 26279347 DOI: 10.1016/j.mvr.2015.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 07/31/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022]
Abstract
We have developed a new fiber-optic system that combines diffuse reflectance spectroscopy (DRS) and laser Doppler Flowmetry (LDF) for a multi-modal assessment of the microcirculation. Quantitative data is achieved with an inverse Monte Carlo algorithm based on an individually adaptive skin model. The output parameters are calculated from the model and given in absolute units: hemoglobin oxygen saturation (%), red blood cell (RBC) tissue fraction (%), and the speed resolved RBC perfusion separated into three speed regions; 0-1mm/s, 1-10mm/s and above 10mm/s (% mm/s). The aim was to explore microcirculatory parameters using the new optical method, integrating DRS and LDF in a joint skin model, during local heating of the dorsal foot and venous and arterial occlusion of the forearm in 23 healthy subjects (age 20-28years). There were differences in the three speed regions in regard to blood flow changes due to local heating, where perfusion for high speeds increased the most. There was also a high correlation between changes in oxygenation and changes in perfusion for higher speeds. Oxygen saturation at baseline was 44% on foot, increasing to 83% at plateau after heating. The larger increase in perfusion for higher speeds than for lower speeds together with the oxygenation increase during thermal provocation, shows a local thermoregulatory blood flow in presumably arteriolar dermal vessels. In conclusion, there are improved possibilities to assess microcirculation using integrated DRS and LDF in a joint skin model by enabling both oxygenation and speed resolved blood flow assessment simultaneously and in the same skin site. Output parameters in absolute units may also yield new insights about the microcirculatory system.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden.
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden; Perimed AB, Datavägen 9A, 175 43 Järfälla, Stockholm, Sweden
| | | | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, 581 85 Linköping, Sweden
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32
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Adingupu DD, Thorn CE, Casanova F, Elyas S, Gooding K, Gilchrist M, Aizawa K, Gates PE, Shore AC, Strain DW. Blood Oxygen Saturation After Ischemia is Altered With Abnormal Microvascular Reperfusion. Microcirculation 2015; 22:294-305. [DOI: 10.1111/micc.12198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/28/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Damilola D. Adingupu
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Clare E. Thorn
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Francesco Casanova
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Salim Elyas
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Kim Gooding
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Mark Gilchrist
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Kunihiko Aizawa
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Phillip E. Gates
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Angela C. Shore
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - David W. Strain
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
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