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Zhao P, Qu F, Fu H, Zhao J, Guo J, Xu J, Ho YP, Chan MK, Bian L. Water-Immiscible Coacervate as a Liquid Magnetic Robot for Intravascular Navigation. J Am Chem Soc 2023; 145:3312-3317. [PMID: 36728932 DOI: 10.1021/jacs.2c13287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Developing magnetic ultrasoft robots to navigate through extraordinarily narrow and confined spaces like capillaries in vivo requires synthesizing materials with excessive deformability, responsive actuation, and rapid adaptability, which are difficult to achieve with the current soft polymeric materials, such as elastomers and hydrogels. We report a magnetically actuatable and water-immiscible (MAWI) coacervate based on the assembled magnetic core-shell nanoparticles to function as a liquid robot. The degradable and biocompatible millimeter-sized MAWI coacervate liquid robot can remain stable under changing pH and salt concentrations, release loaded cargoes on demand, squeeze through an artificial capillary network within seconds, and realize intravascular targeting in vivo guided by an external magnetic field. We believe the proposed "coacervate-based liquid robot" can implement demanding tasks beyond the capability of conventional elastomer or hydrogel-based soft robots in the field of biomedicine and represents a distinct design strategy for high-performance ultrasoft robots.
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Affiliation(s)
- Pengchao Zhao
- School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou 511442, P. R. China.,Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China.,Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China
| | - Fuyang Qu
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China
| | - Hao Fu
- School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou 511442, P. R. China
| | - Jianyang Zhao
- School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou 511442, P. R. China
| | - Jiaxin Guo
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China
| | - Jiankun Xu
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China.,Department of Orthopaedics, The First Affiliated Hospital, Shantou University, Shantou 515041, P. R. China
| | - Yi-Ping Ho
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China
| | - Michael K Chan
- School of Life Sciences and Center of Novel Biomaterials, The Chinese University of Hong Kong, Hong Kong 999077, P. R. China
| | - Liming Bian
- School of Biomedical Sciences and Engineering, Guangzhou International Campus, South China University of Technology, Guangzhou 511442, P. R. China.,National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, P. R. China.,Guangdong Provincial Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006, P. R. China.,Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, P. R. China
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Multiphysics and multiscale modeling of microthrombosis in COVID-19. PLoS Comput Biol 2022; 18:e1009892. [PMID: 35255089 PMCID: PMC8901059 DOI: 10.1371/journal.pcbi.1009892] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/02/2022] [Indexed: 12/21/2022] Open
Abstract
Emerging clinical evidence suggests that thrombosis in the microvasculature of patients with Coronavirus disease 2019 (COVID-19) plays an essential role in dictating the disease progression. Because of the infectious nature of SARS-CoV-2, patients’ fresh blood samples are limited to access for in vitro experimental investigations. Herein, we employ a novel multiscale and multiphysics computational framework to perform predictive modeling of the pathological thrombus formation in the microvasculature using data from patients with COVID-19. This framework seamlessly integrates the key components in the process of blood clotting, including hemodynamics, transport of coagulation factors and coagulation kinetics, blood cell mechanics and adhesive dynamics, and thus allows us to quantify the contributions of many prothrombotic factors reported in the literature, such as stasis, the derangement in blood coagulation factor levels and activities, inflammatory responses of endothelial cells and leukocytes to the microthrombus formation in COVID-19. Our simulation results show that among the coagulation factors considered, antithrombin and factor V play more prominent roles in promoting thrombosis. Our simulations also suggest that recruitment of WBCs to the endothelial cells exacerbates thrombogenesis and contributes to the blockage of the blood flow. Additionally, we show that the recent identification of flowing blood cell clusters could be a result of detachment of WBCs from thrombogenic sites, which may serve as a nidus for new clot formation. These findings point to potential targets that should be further evaluated, and prioritized in the anti-thrombotic treatment of patients with COVID-19. Altogether, our computational framework provides a powerful tool for quantitative understanding of the mechanism of pathological thrombus formation and offers insights into new therapeutic approaches for treating COVID-19 associated thrombosis. Emerging clinical evidence suggests that thrombosis in the microvasculature of patients with Coronavirus disease 2019 (COVID-19) plays an essential role in dictating the disease progression. We employ a novel multiphysics and multiscale computational framework to investigate the underlying mechanism of the pathological formation of microthrombi and circulating cell clusters in COVID-19. We quantify the contributions of many prothrombotic factors reported in the literature, such as stasis, the derangement in blood coagulation factor levels and activities, inflammatory responses of endothelial cells and leukocytes to the microthrombus formation in COVID-19, through which we identify the potential targets that should be further evaluated, and prioritized in the anti-thrombotic treatment of patients with COVID-19.
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Follain G, Osmani N, Gensbittel V, Asokan N, Larnicol A, Mercier L, Garcia-Leon MJ, Busnelli I, Pichot A, Paul N, Carapito R, Bahram S, Lefebvre O, Goetz JG. Impairing flow-mediated endothelial remodeling reduces extravasation of tumor cells. Sci Rep 2021; 11:13144. [PMID: 34162963 PMCID: PMC8222393 DOI: 10.1038/s41598-021-92515-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 05/31/2021] [Indexed: 01/02/2023] Open
Abstract
Tumor progression and metastatic dissemination are driven by cell-intrinsic and biomechanical cues that favor the growth of life-threatening secondary tumors. We recently identified pro-metastatic vascular regions with blood flow profiles that are permissive for the arrest of circulating tumor cells. We have further established that such flow profiles also control endothelial remodeling, which favors extravasation of arrested CTCs. Yet, how shear forces control endothelial remodeling is unknown. In the present work, we aimed at dissecting the cellular and molecular mechanisms driving blood flow-dependent endothelial remodeling. Transcriptomic analysis of endothelial cells revealed that blood flow enhanced VEGFR signaling, among others. Using a combination of in vitro microfluidics and intravital imaging in zebrafish embryos, we now demonstrate that the early flow-driven endothelial response can be prevented upon specific inhibition of VEGFR tyrosine kinase and subsequent signaling. Inhibitory targeting of VEGFRs reduced endothelial remodeling and subsequent metastatic extravasation. These results confirm the importance of VEGFR-dependent endothelial remodeling as a driving force of CTC extravasation and metastatic dissemination. Furthermore, the present work suggests that therapies targeting endothelial remodeling might be a relevant clinical strategy in order to impede metastatic progression.
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Affiliation(s)
- Gautier Follain
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
- Turku Bioscience Center,, University of Turku, Åbo Akademi University, 20520, Turku, Finland
| | - Naël Osmani
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Valentin Gensbittel
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Nandini Asokan
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Annabel Larnicol
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Luc Mercier
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
- UMR 5297, Interdisciplinary Institute for Neurosciences, CNRS Université de Bordeaux, 33076, Bordeaux, France
| | - Maria Jesus Garcia-Leon
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Ignacio Busnelli
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
- Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Angelique Pichot
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
| | - Nicodème Paul
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
| | - Raphaël Carapito
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
| | - Seiamak Bahram
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France
| | - Olivier Lefebvre
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France.
- Université de Strasbourg, 67000, Strasbourg, France.
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France.
- Equipe Labellisée Ligue Contre le Cancer, Paris, France.
| | - Jacky G Goetz
- Tumor Biomechanics, INSERM UMR_S1109, CRBS, 67000, Strasbourg, France.
- Université de Strasbourg, 67000, Strasbourg, France.
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), 67000, Strasbourg, France.
- Equipe Labellisée Ligue Contre le Cancer, Paris, France.
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Ma Q, Hu CT, Yue J, Luo Y, Qiao F, Chen LQ, Zhang ML, Du ZY. High-carbohydrate diet promotes the adaptation to acute hypoxia in zebrafish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:665-679. [PMID: 31820205 DOI: 10.1007/s10695-019-00742-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Oxygen deprivation (hypoxia) is a common challenge in water environment, which causes lack of energy and oxidative damage in organisms. Many studies have indicated a number of physiological and metabolic changes under hypoxia, but the effects of dietary nutrients on hypoxia tolerance have not been well evaluated. In the present 7-week feeding trial, we fed zebrafish with low-protein diet (LP), high-protein diet (HP), low-fat diet (LF), high-fat diet (HF), low-carbohydrate diet (LC), and high-carbohydrate diet (HC), respectively. Afterward, the resistance to acute hypoxia challenge, growth, body composition, activities of metabolic enzymes, and expressions of energy homeostasis-related genes and six hifαs genes were measured. The results indicated that only the HC diet could significantly improve the resistance to hypoxia challenge. Moreover, the HC diet feeding caused higher glycogen deposition in the liver and muscle, and these glycogens were significantly reduced after 6-h acute hypoxia challenge. Meanwhile, the lactate content in the liver and blood was increased in the HC groups. At hypoxia status, the relative mRNA expressions of the genes related to glycolysis, ATP production, insulin signaling pathway, and hif-3a (hif1al) were all significantly increased in the muscle of the HC diet-fed fish. This study revealed that high-carbohydrate diet could improve the resistance to hypoxia by activating glycolysis and hif/insulin signaling pathway in zebrafish, mainly in the muscle, to efficiently supply energy. Therefore, our results highlight the importance of dietary carbohydrate in resisting hypoxia in fish.
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Affiliation(s)
- Qiang Ma
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Chun-Ting Hu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Junjiayu Yue
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Yuan Luo
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Fang Qiao
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China.
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Ye F, Yin S, Li M, Li Y, Zhong J. In-vivo full-field measurement of microcirculatory blood flow velocity based on intelligent object identification. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-11. [PMID: 31970945 PMCID: PMC6975132 DOI: 10.1117/1.jbo.25.1.016003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 12/30/2019] [Indexed: 05/09/2023]
Abstract
Microcirculation plays a crucial role in delivering oxygen and nutrients to living tissues and in removing metabolic wastes from the human body. Monitoring the velocity of blood flow in microcirculation is essential for assessing various diseases, such as diabetes, cancer, and critical illnesses. Because of the complex morphological pattern of the capillaries, both In-vivo capillary identification and blood flow velocity measurement by conventional optical capillaroscopy are challenging. Thus, we focused on developing an In-vivo optical microscope for capillary imaging, and we propose an In-vivo full-field flow velocity measurement method based on intelligent object identification. The proposed method realizes full-field blood flow velocity measurements in microcirculation by employing a deep neural network to automatically identify and distinguish capillaries from images. In addition, a spatiotemporal diagram analysis is used for flow velocity calculation. In-vivo experiments were conducted, and the images and videos of capillaries were collected for analysis. We demonstrated that the proposed method is highly accurate in performing full-field blood flow velocity measurements in microcirculation. Further, because this method is simple and inexpensive, it can be effectively employed in clinics.
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Affiliation(s)
- Fei Ye
- Jinan University, Department of Optoelectronic Engineering, Guangzhou, China
| | - Songchao Yin
- Sun Yat-sen University, Third Affiliated Hospital, Department of Dermatology, Guangzhou, China
| | - Meirong Li
- Sun Yat-sen University, Third Affiliated Hospital, Department of Dermatology, Guangzhou, China
| | - Yujie Li
- Sun Yat-sen University, Sixth Affiliated Hospital, Reproductive Medicine Center, Guangzhou, China
| | - Jingang Zhong
- Jinan University, Department of Optoelectronic Engineering, Guangzhou, China
- Address all correspondence to Jingang Zhong, E-mail:
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Ivanov KP, Mel'nikova NN. Blood circulation in rat lungs under conditions of reduced oxygen level in inhaled air. Bull Exp Biol Med 2013; 154:199-202. [PMID: 23330124 DOI: 10.1007/s10517-012-1911-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
According to some authors, reduction in oxygen level in the lung alveoli results in constriction of afferent vessels, while others observed no vessel constriction. The issue is of principle importance in relation to the lung involvement in body adaptation to hypoxia. Conventional methods are inefficient to solve it, therefore we used a contact microscope allowing observation of lung circulatory system structure and condition of the lung circulatory system in whole, virtually intact animal, on whole undamaged lungs in situ, at normal physiological lung position in the thorax. We found that large vessels carrying blood to the alveoli do not constrict or dilate at reduced Po(2)in lung alveoli. These vessels with a diameter of 15 to 40 μ and more are the only blood source for alveoli.
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Affiliation(s)
- K P Ivanov
- Group of Thermoregulation Physiology and Bioenergetics, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia.
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Circulation in the lungs and microcirculation in the alveoli. Respir Physiol Neurobiol 2013; 187:26-30. [DOI: 10.1016/j.resp.2013.02.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/23/2013] [Accepted: 02/25/2013] [Indexed: 11/21/2022]
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New Data on the Process of Circulation and Blood Oxygenation in the Lungs under Physiological Conditions. Bull Exp Biol Med 2013; 154:411-4. [DOI: 10.1007/s10517-013-1963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ivanov KP. Function of alveoli as a result of evolutionary development of respiratory system in mammals. J EVOL BIOCHEM PHYS+ 2013. [DOI: 10.1134/s002209301301009x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Microcirculation in the lungs: special features of construction and dynamics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 756:197-201. [PMID: 22836636 DOI: 10.1007/978-94-007-4549-0_25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
In this study we investigated microcirculation in the lungs in their in situ physiological location inside the thorax. The study was performed with the use of a system of contact optics. A 'window', 4 × 4 mm in size, was made in thorax tissues and pleura of an anaesthetized rat. The lung collapsed and then was filled with oxygen or hypoxic gas mixture under the pressure of 10-15 cm H(2)O through a tracheostomic canula. This almost excluded the respiratory movements of the lung. Then, the lung was brought in contact with a lens (1.7 mm aperture). We showed that there is a whole system of wide microvessels (20-30 μm in diameter) which run between the alveoli; the finding contradicting the hitherto notion that each alveolus is supplied with blood via the thinnest (5-10 μm in diameter) lung arterioles. The microvessels we visualized surround each alveolus almost from all sides. In this way, each alveolus receives a maximum amount of blood. Such a structure of lung circulation accounts for a substantial blood flow through the lungs (up to 6 l per min in humans) and for a rapid saturation of the blood with oxygen (about 100 ml per second). The alveoli saturate the blood with oxygen and subsequently the microvessels form the lung veins entering the left auricle. The photographs and video films of the alveoli at a high magnification were presented, demonstrate the special features of the structure and circulation in the alveoli. The plausible mechanisms of rapid saturation of the blood with oxygen are discussed.
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Ivanov KP. Evolution of pulmonary respiration in the higher mammals. J EVOL BIOCHEM PHYS+ 2012. [DOI: 10.1134/s0022093012020119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Jia Y, Li P, Dziennis S, Wang RK. Responses of peripheral blood flow to acute hypoxia and hyperoxia as measured by optical microangiography. PLoS One 2011; 6:e26802. [PMID: 22046363 PMCID: PMC3201975 DOI: 10.1371/journal.pone.0026802] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Accepted: 10/04/2011] [Indexed: 12/18/2022] Open
Abstract
Oxygen availability is regarded as a critical factor to metabolically regulate systemic blood flow. There is a debate as to how peripheral blood flow (PBF) is affected and modulated during hypoxia and hyperoxia; however in vivo evaluating of functional PBF under oxygen-related physiological perturbation remains challenging. Microscopic observation, the current frequently used imaging modality for PBF characterization often involves the use of exogenous contrast agents, which would inevitably perturb the intrinsic physiologic responses of microcirculation being investigated. In this paper, optical micro-angiography (OMAG) was employed that uses intrinsic optical scattering signals backscattered from blood flows for imaging PBF in skeletal muscle challenged by the alteration of oxygen concentration. By utilizing optical reflectance signals, we demonstrated that OMAG is able to show the response of hemodynamic activities upon acute hypoxia and hyperoxia, including the modulation of macrovascular caliber, microvascular density, and flux regulation within different sized vessels within skeletal muscle in mice in vivo. Our results suggest that OMAG is a promising tool for in vivo monitoring of functional macro- or micro-vascular responses within peripheral vascular beds.
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Affiliation(s)
- Yali Jia
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Peng Li
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Suzan Dziennis
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Jia Y, Li P, Wang RK. Optical microangiography provides an ability to monitor responses of cerebral microcirculation to hypoxia and hyperoxia in mice. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:096019. [PMID: 21950933 PMCID: PMC3188643 DOI: 10.1117/1.3625238] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/19/2011] [Accepted: 07/20/2011] [Indexed: 05/18/2023]
Abstract
In vivo imaging of microcirculation can improve our fundamental understanding of cerebral microhemodynamics under various physiological challenges, such as hypoxia and hyperoxia. However, existing techniques often involve the use of invasive procedures or exogenous contrast agents, which would inevitably perturb the intrinsic physiologic responses of microcirculation being investigated. We report ultrahigh sensitive optical microangiography (OMAG) for label-free monitoring of microcirculation responses challenged by oxygen inhalation. For the first time, we demonstrate that OMAG is capable of showing the impact of acute hypoxia and hyperoxia on microhemodynamic activities, including the passive and active modulation of microvascular density and flux regulation, within capillary and noncapillary vessels in rodents in vivo. The ability of OMAG to functionally image the intact microcirculation promises future applications for studying cerebral diseases.
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Affiliation(s)
- Yali Jia
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA
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Structure of Microvascular Networks in the Lungs and Peculiarities of Blood Circulation in Them. Bull Exp Biol Med 2011; 151:389-91. [DOI: 10.1007/s10517-011-1338-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Zamboni V, Cesari M, Zuccalà G, Onder G, Woodman RC, Maraldi C, Ranzini M, Volpato S, Pahor M, Bernabei R. Anemia and cognitive performance in hospitalized older patients: results from the GIFA study. Int J Geriatr Psychiatry 2006; 21:529-34. [PMID: 16783797 DOI: 10.1002/gps.1520] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Anemia represents a major risk factor for adverse health-related events in older persons. The aim of this study was to evaluate the association between hemoglobin levels/anemia and cognitive function in hospitalized older persons. METHOD Data are from the Gruppo Italiano di Farmacovigilanza nell'Anziano (GIFA) study. Hemoglobin levels (in g/dL) were measured upon admission to hospital; anemia was defined according to the WHO criteria. Cognitive performance was assessed by the Abbreviated Mental Test (AMT) on admission; an AMT score <7 defined cognitive impairment. Logistic regressions and analyses of covariance were performed to evaluate the relationship between cognitive status and hemoglobin levels/anemia. RESULTS Mean age of the sample (n = 13,301) was 72.0 years. Participants with cognitive impairment presented a higher prevalence of anemia (47%) compared to those without cognitive impairment (35%, p < 0.001). Adjusted logistic regressions showed that hemoglobin levels/anemia were significantly associated with cognitive impairment (OR = 0.96, 95%CI = 0.94-0.99, p = 0.004, and OR = 1.32, 95%CI = 1.18-1.48, p < 0.001, respectively). Patients with anemia and cognitive impairment at the hospital admission presented a higher number of impaired Activities of Daily Living compared to those with only one or none of the studied conditions (p for trend < 0.001). CONCLUSION Low hemoglobin levels and anemia are independently associated with cognitive performance in older persons admitted to acute care units.
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Affiliation(s)
- Valentina Zamboni
- Department of Gerontology, Geriatrics and Physiatry, Catholic University of Sacred Heart, Rome, Italy.
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Jung JC, Mehta AD, Aksay E, Stepnoski R, Schnitzer MJ. In vivo mammalian brain imaging using one- and two-photon fluorescence microendoscopy. J Neurophysiol 2004; 92:3121-33. [PMID: 15128753 PMCID: PMC2826362 DOI: 10.1152/jn.00234.2004] [Citation(s) in RCA: 224] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
One of the major limitations in the current set of techniques available to neuroscientists is a dearth of methods for imaging individual cells deep within the brains of live animals. To overcome this limitation, we developed two forms of minimally invasive fluorescence microendoscopy and tested their abilities to image cells in vivo. Both one- and two-photon fluorescence microendoscopy are based on compound gradient refractive index (GRIN) lenses that are 350-1,000 microm in diameter and provide micron-scale resolution. One-photon microendoscopy allows full-frame images to be viewed by eye or with a camera, and is well suited to fast frame-rate imaging. Two-photon microendoscopy is a laser-scanning modality that provides optical sectioning deep within tissue. Using in vivo microendoscopy we acquired video-rate movies of thalamic and CA1 hippocampal red blood cell dynamics and still-frame images of CA1 neurons and dendrites in anesthetized rats and mice. Microendoscopy will help meet the growing demand for in vivo cellular imaging created by the rapid emergence of new synthetic and genetically encoded fluorophores that can be used to label specific brain areas or cell classes.
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Affiliation(s)
- Juergen C Jung
- Department of Biological Sciences, Stanford University, Stanford, CA 94305-5435, USA
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18
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Krolo I, Hudetz AG. Hypoxemia alters erythrocyte perfusion pattern in the cerebral capillary network. Microvasc Res 2000; 59:72-9. [PMID: 10625573 DOI: 10.1006/mvre.1999.2185] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of acute hypoxemia on erythrocyte perfusion rates in individual capillaries of the rat cerebral cortex was studied by intravital video microscopy. The motion of erythrocytes in subsurface capillaries of the frontoparietal cortex was visualized through a closed cranial window using fluorescently labeled red blood cells (FRBC) as markers of flow. FRBC velocity and FRBC supply rate were measured in each capillary at rest, moderate hypoxemia (PaO(2) = 40 mm Hg), and severe hypoxemia (PaO(2) = 26 mm Hg). Lineal density of FRBC in the capillaries was calculated as the ratio of supply rate and velocity. Hypoxemia increased erythrocyte perfusion in virtually all capillaries. Average FRBC supply rate increased by 104% in moderate hypoxemia and by 281% in severe hypoxemia. Average FRBC velocity increased by 66 and 173%, respectively. During severe hypoxemia, FRBC supply rate increased significantly more in capillaries with low resting supply rate compared to those with high resting supply rate. Changes in FRBC velocity exhibited a similar pattern. Lineal density of FRBC increased by 28% in moderate hypoxemia and by 48% in severe hypoxemia. The results suggest that acute hypoxemia promotes perfusion homogeneity and recruitment of erythrocytes in the cerebral capillary network.
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Affiliation(s)
- I Krolo
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
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19
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LaManna JC. Rat brain adaptation to chronic hypobaric hypoxia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1992; 317:107-14. [PMID: 1288116 DOI: 10.1007/978-1-4615-3428-0_9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- J C LaManna
- Dept of Neurology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
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20
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Gutierrez G, Lund N, Bryan-Brown CW. Cellular Oxygen Utilization During Multiple Organ Failure. Crit Care Clin 1989. [DOI: 10.1016/s0749-0704(18)30436-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Sharan M, Singh MP, Saxena RK, Sud I. Numerical simulation of systemic O2 and CO2 exchange in a hyperbaric environment. Biosystems 1989; 23:21-30. [PMID: 2516472 DOI: 10.1016/0303-2647(89)90005-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The process of gas exchange in systemic capillaries and its surrounding tissue is simulated numerically in a hyperbaric environment, taking into account the molecular diffusion, convection, saturation of haemoglobin with O2 and CO2, and the metabolic activity in the tissue. Krogh tissue-cylinder is used as a geometrical representation of the capillary-tissue system. The resulting system of non-linear governing equations together with the physiologically relevant boundary conditions is solved numerically. It is found that the concentration of oxygen decreases from the axis of the capillary to the tissue periphery whereas the concentration of carbon dioxide increases. It is shown that very little CO2 is transported radially. The location of the vulnerable region from the point of view of CO2 accumulation is found to be the rim (r = R2, z = L) situated at the periphery of the tissue near the venous end of the capillary. It is also found that accumulation of O2 decreases whereas that of CO2 increases in a hyperbaric environment. Finally, it is surmised that one of the reasons in causing discomfort among divers could be excessive accumulation of CO2 in the tissue.
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Affiliation(s)
- M Sharan
- Centre for Atmospheric Sciences, Indian Institute of Technology, Delhi Hauz Khas, New Delhi, India
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22
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Shockley RP, LaManna JC. Determination of rat cerebral cortical blood volume changes by capillary mean transit time analysis during hypoxia, hypercapnia and hyperventilation. Brain Res 1988; 454:170-8. [PMID: 3409001 DOI: 10.1016/0006-8993(88)90816-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Changes in cerebral blood volume due to augmented or diminished numbers of blood-perfused capillaries can be studied in small animals by optical methods. Capillary mean transit time was determined by detection of the passage of a hemodilution bolus through a region of the parietal cerebral cortical surface, using a reflectance spectrophotometer through a small craniotomy in chloral hydrate-anesthetized rats. Local cerebral blood flow was determined in the same region by the butanol indicator-fractionation method. Blood volume was calculated from the product of blood flow and transit time. Normoxic, normocapnic values for these variables were blood flow = 144 ml/100 g/min; mean transit time = 1.41 s; and blood volume = 3.4 ml/100 g. Mean transit time reached a minimum (1.1 s) with moderate hypoxia or hypercapnia. Combined hypoxia and hypercapnia did not result in any further decrease in mean transit time although blood flow was much higher than either hypoxia or hypercapnia alone. The maximum blood volume recorded during hypercapnic hypoxia (12.1 ml/100 g) was 3.6 times greater than that at normoxic normocapnia, which suggests that under control conditions in the anesthetized rat considerably less than 100% of the cerebral capillaries were actively perfusing the tissue. These studies demonstrate that optical methods can be used to quantitatively measure blood volume. The data suggest that capillary recruitment is a physiologically significant phenomenon in rat cerebral cortex.
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Affiliation(s)
- R P Shockley
- Department of Neurology, University Hospital, Cleveland, OH 44106
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Menger MD, Sack FU, Barker JH, Feifel G, Messmer K. Quantitative analysis of microcirculatory disorders after prolonged ischemia in skeletal muscle. Therapeutic effects of prophylactic isovolemic hemodilution. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1988; 188:151-65. [PMID: 3420298 DOI: 10.1007/bf01852316] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Reperfusion injury following prolonged ischemia is thought to be caused primarily by microvascular failure. The aim of the present study was to investigate whether prophylactic isovolemic hemodilution with Dextran 60 (hct 30%) could improve microvascular perfusion after 4 h of pressure-induced ischemia in skeletal muscle. In 28 Syrian golden hamsters (6-8 weeks/60-80 g b. wt.) a dorsal skinfold chamber and permanent arterial and venous catheters were implanted under Nembutal anesthesia (50 mg/kg b. wt.). Following a recovery period of 48 h pressure-induced ischemia was applied to the skeletal muscle within the skinfold chamber by means of a transparent stamp. Quantitative analyses of microhemodynamics were performed in the awake animal prior to and 15 min, 1, 2, 4 and 24 h after ischemia using vital fluorescence microscopy. In non-treated animals, functional capillary density decreased after 4 h of ischemia to 30% of the initial values (P less than 0.001); after 24-h reperfusion only 50% of the initially perfused capillaries were reperfused (P less than 0.001). The heterogeneity of functional capillary density increased after ischemia to a maximum of 2.19 +/- 0.94 as compared to 0.48 +/- 0.11 prior to ischemia. Capillary RBC-velocity suffered a marked reduction in the early reperfusion phase and did not recover up to the 24-h observation time. In contrast, prophylactic isovolemic hemodilution was associated with only a small and reversible reduction of functional capillary density after 4-h ischemia. At 24-h reperfusion 90% of the initially perfused capillaries were reperfused. Capillary RBC-velocity was reduced in the early reperfusion phase, but returned to normal values within 24 h. Thus, prophylactic isovolemic hemodilution resulted in a marked reduction of microvascular reperfusion failure in skeletal muscle. A hematocrit lower than normal prior to ischemia provides better conditions for capillary reperfusion after prolonged ischemia.
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Affiliation(s)
- M D Menger
- Dept. of General Surgery and Abdominal Surgery, University of Saarland, Homburg/Saar, Federal Republic of Germany
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24
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Single-fiber laser Doppler flowmetry. A method for deep tissue perfusion measurements. Med Biol Eng Comput 1987; 25:329-34. [PMID: 2966881 DOI: 10.1007/bf02447433] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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