1
|
Margolis EA, Friend NE, Rolle MW, Alsberg E, Putnam AJ. Manufacturing the multiscale vascular hierarchy: progress toward solving the grand challenge of tissue engineering. Trends Biotechnol 2023; 41:1400-1416. [PMID: 37169690 PMCID: PMC10593098 DOI: 10.1016/j.tibtech.2023.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/05/2023] [Accepted: 04/14/2023] [Indexed: 05/13/2023]
Abstract
In human vascular anatomy, blood flows from the heart to organs and tissues through a hierarchical vascular tree, comprising large arteries that branch into arterioles and further into capillaries, where gas and nutrient exchange occur. Engineering a complete, integrated vascular hierarchy with vessels large enough to suture, strong enough to withstand hemodynamic forces, and a branching structure to permit immediate perfusion of a fluidic circuit across scales would be transformative for regenerative medicine (RM), enabling the translation of engineered tissues of clinically relevant size, and perhaps whole organs. How close are we to solving this biological plumbing problem? In this review, we highlight advances in engineered vasculature at individual scales and focus on recent strategies to integrate across scales.
Collapse
Affiliation(s)
- Emily A Margolis
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, MI, USA
| | - Nicole E Friend
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, MI, USA
| | - Marsha W Rolle
- Worcester Polytechnic Institute, Department of Biomedical Engineering, Worcester, MA, USA
| | - Eben Alsberg
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, IL, USA
| | - Andrew J Putnam
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, MI, USA.
| |
Collapse
|
2
|
Hyakutake T, Abe H, Miyoshi Y, Yasui M, Suzuki R, Tsurumaki S, Tsutsumi Y. In vitro study on the partitioning of red blood cells using a microchannel network. Microvasc Res 2021; 140:104281. [PMID: 34871649 DOI: 10.1016/j.mvr.2021.104281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 11/11/2021] [Accepted: 11/13/2021] [Indexed: 11/18/2022]
Abstract
To investigate the partitioning properties of red blood cells (RBCs) in the bifurcating capillary vessels, an in vitro experiment was performed to perfuse human RBC suspensions into the microfluidic channels with a width of <10 μm. Two types of microchannel geometries were established. One is a single model comprising one parent and two daughter channels with different widths, and the other is a network model that had a symmetric geometry with four consecutive divergences and convergences. In addition to the fractional RBC flux at each bifurcation, changes in hematocrit levels and flow velocity before and after the bifurcation were investigated. In the single model, non-uniform partitioning of RBCs was observed, and this result was in good agreement with that of the empirical model. Furthermore, in the network model, the RBC distribution in the cross-section before the bifurcation significantly affected RBC partitioning in the two channels after the bifurcation. Hence, there was a large RBC heterogeneity in the capillary network. The hematocrit levels between the channels differed for more than one order of magnitude. Therefore, the findings of the current research could facilitate a better understanding of RBC partitioning properties in the microcirculatory system.
Collapse
Affiliation(s)
- Toru Hyakutake
- Faculty of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan.
| | - Hiroki Abe
- Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan
| | - Yohei Miyoshi
- Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan
| | - Manabu Yasui
- Kanagawa Institute of Industrial Science and Technology, 705-1, Shimoimaizumi, Ebina 243-0435, Japan
| | - Rina Suzuki
- Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan
| | - Shunto Tsurumaki
- Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan
| | - Yuya Tsutsumi
- Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama 240-8501, Japan
| |
Collapse
|
3
|
Massamba N, Mackin AG, Chun LY, Rodriguez S, Dimitroyannis RC, Bodaghi B, Hariprasad SM, Skondra D. Evaluation of flow of chorioretinal capillaries in healthy black and white subjects using optical coherence tomography angiography. Sci Rep 2021; 11:21886. [PMID: 34750481 PMCID: PMC8575995 DOI: 10.1038/s41598-021-01380-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 10/11/2021] [Indexed: 12/18/2022] Open
Abstract
This study compared macular capillary parameters between healthy black and white subjects using optical coherence tomography angiography (OCTA). We measured vessel density (VD) of superficial (SCP), intermediate (ICP), and deep (DCP) capillary plexuses and choriocapillaris blood flow area (BFA) of the fovea, parafovea and total 3 mm-diameter circular area centered on the fovea, as well as the foveal avascular zone (FAZ) parameters, controlling for axial length. Black subjects had lower foveal and parafoveal VD in the SCP (p = 0.043 and p = 0.014) and the ICP (p = 0.014 and p = 0.002). In the DCP, black subjects had a trend toward lower foveal and parafoveal VD. Black subjects had decreased choriocapillaris BFA in the total 3 mm area (p = 0.011) and the parafovea (p = 0.033), larger FAZ area (p = 0.006) and perimeter (p = 0.014), and a higher capillary density in a 300 μm wide region around the FAZ (FD-300) (p = 0.001). There was no significant difference in FAZ acircularity index. To our knowledge, this is the first report analyzing the three distinct retinal capillary plexuses and identifying differing baseline VD, choriocapillaris and FAZ parameters in healthy young black compared to white subjects. Larger studies are needed to validate these findings and better understand racial differences in vulnerability to ocular diseases.
Collapse
Affiliation(s)
- Nathalie Massamba
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
- Department of Ophthalmology, Handicap, and Vision, Pitie Salpetriere Hospital, Sorbonne University, Paris, France
- J. Terry Ernest Ocular Imaging Center, The University of Chicago, Chicago, IL, USA
| | - Anna G Mackin
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
| | - Lindsay Y Chun
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
| | - Sarah Rodriguez
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
| | - Rose C Dimitroyannis
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
| | - Bahram Bodaghi
- Department of Ophthalmology, Handicap, and Vision, Pitie Salpetriere Hospital, Sorbonne University, Paris, France
| | - Seenu M Hariprasad
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA
| | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, The University of Chicago, 5841 S. Maryland Avenue, S426m MC2114, Chicago, IL, 60637, USA.
- J. Terry Ernest Ocular Imaging Center, The University of Chicago, Chicago, IL, USA.
| |
Collapse
|
4
|
McDermott MM, Dayanidhi S, Kosmac K, Saini S, Slysz J, Leeuwenburgh C, Hartnell L, Sufit R, Ferrucci L. Walking Exercise Therapy Effects on Lower Extremity Skeletal Muscle in Peripheral Artery Disease. Circ Res 2021; 128:1851-1867. [PMID: 34110902 DOI: 10.1161/circresaha.121.318242] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Walking exercise is the most effective noninvasive therapy that improves walking ability in peripheral artery disease (PAD). Biologic mechanisms by which exercise improves walking in PAD are unclear. This review summarizes evidence regarding effects of walking exercise on lower extremity skeletal muscle in PAD. In older people without PAD, aerobic exercise improves mitochondrial activity, muscle mass, capillary density, and insulin sensitivity in skeletal muscle. However, walking exercise increases lower extremity ischemia in people with PAD, and therefore, mechanisms by which this exercise improves walking may differ between people with and without PAD. Compared with people without PAD, gastrocnemius muscle in people with PAD has greater mitochondrial impairment, increased reactive oxygen species, and increased fibrosis. In multiple small trials, walking exercise therapy did not consistently improve mitochondrial activity in people with PAD. In one 12-week randomized trial of people with PAD randomized to supervised exercise or control, supervised treadmill exercise increased treadmill walking time from 9.3 to 15.1 minutes, but simultaneously increased the proportion of angular muscle fibers, consistent with muscle denervation (from 7.6% to 15.6%), while angular myofibers did not change in the control group (from 9.1% to 9.1%). These findings suggest an adaptive response to exercise in PAD that includes denervation and reinnervation, an adaptive process observed in skeletal muscle of people without PAD during aging. Small studies have not shown significant effects of exercise on increased capillary density in lower extremity skeletal muscle of participants with PAD, and there are no data showing that exercise improves microcirculatory delivery of oxygen and nutrients in patients with PAD. However, the effects of supervised exercise on increased plasma nitrite abundance after a treadmill walking test in people with PAD may be associated with improved lower extremity skeletal muscle perfusion and may contribute to improved walking performance in response to exercise in people with PAD. Randomized trials with serial, comprehensive measures of muscle biology, and physiology are needed to clarify mechanisms by which walking exercise interventions improve mobility in PAD.
Collapse
Affiliation(s)
- Mary M McDermott
- Department of Medicine and Preventive Medicine (M.M.M., J.S.), Northwestern University Feinberg School of Medicine
| | - Sudarshan Dayanidhi
- Shirley Ryan Ability Laboratory (S.D.), Northwestern University Feinberg School of Medicine
| | - Kate Kosmac
- Center for Muscle Biology, University of Kentucky (K.K.)
| | - Sunil Saini
- Jawaharlal Nehru University, School of Biotechnology, New Delhi, India (S.S.)
| | - Joshua Slysz
- Department of Medicine and Preventive Medicine (M.M.M., J.S.), Northwestern University Feinberg School of Medicine
| | | | - Lisa Hartnell
- Division of Intramural Research, National Institute on Aging (L.H., L.F.)
| | - Robert Sufit
- Department of Neurology (R.S.), Northwestern University Feinberg School of Medicine
| | - Luigi Ferrucci
- Division of Intramural Research, National Institute on Aging (L.H., L.F.)
| |
Collapse
|
5
|
Blyschak N, Nebesna Z, Borys R, Kyryk K, Dzhalilova E. [MICRO- AND ULTRASTRUCTURAL RECONSTRUCTION OF THE RAT SUBMANDIBULAR GLAND IN THE LATE STAGES OF EXPERIMENTAL TYPE 2 DIABETES MELLITUS]. Georgian Med News 2020:125-131. [PMID: 32242859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electron microscopic investigations of the animals' submandibular gland, conducted in 6 weeks of the experiment, established that ultrastructural changes increase in glandular cells of terminal secretory units in comparison with early period of the experiment. Serocytes have osmiophilic, rather small or picnotic nuclei. Perinuclear spaces of karyolemma are uneven, external nuclear membrane forms local protrusions. Electron density of the karyoplasm is significant, appearing homogenous, nuclei are not observed. Evident submicroscopic changes in blood capillaries of the submandibular gland in experimental diabetes mellitus indicate the impairment of blood-tissue barrier and transcapillary exchange. Deep destructive modifications of all branches of microcirculatory blood flow of the submandibular gland are observed in 8-week course of experimental diabetes mellitus. As compared with the 6th week of investigation, a reliable slight dilation of organ artery diameter, dilation of the diameter of interlobular arterioles, dilation of the diameter of intralobular (precapillary) arteriole and dilation of the capillary diameter were observed. Dilation, as compared to 6th weeks of the experiment, of postcapillary venules was observed. Compared to the indices of the 6th weeks of the experiment, an index of trophic activity of the submandibular gland tissuereaches its maximum meaning and an index of packing density of the capillaries reaches its minimum meaning. Capillary network loses delicate, tortuous pattern and often breaks due to destruction of the capillary component. Arteriovenous anastomoses dilate and blood from the arterioles flows into the venous bed avoiding destructed capillaries. Venules are dilated; thin-walled, retained fragments of the capillaries are significantly dilated in some areas. Swelling of connective tissue stroma and significant swelling of the interstitium are observed. Walls of the capillaries and venules are deformed. The walls of the arterioles are thickened due to plasmorrhagia, sclerosis and hyalinosis.
Collapse
Affiliation(s)
- N Blyschak
- 1Lviv National Medical University named after Danil Galitsky, Ukraine
| | - Z Nebesna
- 2I. Horbachevsky Ternopil National Medical University, Ministry of Health of Ukraine
| | - R Borys
- 1Lviv National Medical University named after Danil Galitsky, Ukraine
| | - Kh Kyryk
- 1Lviv National Medical University named after Danil Galitsky, Ukraine
| | - E Dzhalilova
- 1Lviv National Medical University named after Danil Galitsky, Ukraine
| |
Collapse
|
6
|
Mastropasqua R, D’Aloisio R, Agnifili L, Zuppardi E, Di Marzio G, Di Nicola M, Porreca A, Guarini D, Totta M, Brescia L, Di Antonio L. Functional and Structural Reliability of Optic Nerve Head Measurements in Healthy Eyes by Means of Optical Coherence Tomography Angiography. ACTA ACUST UNITED AC 2020; 56:medicina56010044. [PMID: 31968630 PMCID: PMC7023288 DOI: 10.3390/medicina56010044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 12/03/2022]
Abstract
Background and Objectives: the aim of the study was to evaluate the repeatability and reproducibility of optical microangiography (OMAG)-based optical coherence tomography angiography (OCTA) in the optic nerve head (ONH) and radial peripapillary capillary (RPC) perfusion assessment of healthy eyes. Materials and Methods: in this observational study, a total of 40 healthy subjects underwent ONH evaluation, using an OMAG-based OCTA system at baseline (T0), after 30 min (T1), and after 7 days (T2). The main outcome measures were the vessel density (VD) and flux index (FI) of the RPCs, as well as peri-papillary retinal nerve fibre layer (pRNFL) thickness. The analysis was performed by two observers independently. The coefficient of repeatability (CR), within the subject coefficient of variation (CVw) and intrasession correlation coefficient (ICC), to evaluate intrasession repeatability of measurements was calculated for each observer. Results: the high intrasession and intersession repeatability and reproducibility were assessed in the two observers for all three outcome measures. Of note, the CRs for the first and the second observer were 0.011 (95% confidence interval (CI) 0.009–0.014) and 0.016 (95% CI 0.013–0.020) for FI, 0.016 (95% CI 0.013–0.021) and 0.017 (95% CI 0.014–0.021) for VD, and 2.400 (95% CI 1.948–3.092) and 3.732 (95% CI 3.064–4.775) for pRNFL thickness, respectively. The agreement between them was excellent for pRNFL assessment and very good for FI and VD. Conclusion: OCTA has a great potential in the accurate assessment of ONH and peri-papillary microcirculation. It allows for repeated and reproducible measurements without multiple scans-related bias, thus guaranteeing an independent operator analysis with good reproducibility and repeatability.
Collapse
Affiliation(s)
- Rodolfo Mastropasqua
- Vitreoretinal Unit, Bristol Eye Hospital, University of Bristol, Bristol BS8 1TH, UK;
- Eye Clinic, Polytechnic University of Marche, 60126 Ancona, Italy
| | - Rossella D’Aloisio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
- Correspondence: ; Tel.: +39-087-135-8410; Fax: +39-087-135-7294
| | - Luca Agnifili
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Eduardo Zuppardi
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Guido Di Marzio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Marta Di Nicola
- Laboratory of Biostatistics, Department of Medical, Oral and Biotechnological Sciences, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy;
| | - Annamaria Porreca
- Department of Economic Studies, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy;
| | - Daniele Guarini
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Michele Totta
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Lorenza Brescia
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| | - Luca Di Antonio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. d’Annunzio Chieti-Pescara, 66100 Chieti, Italy; (L.A.); (E.Z.); (G.D.M.); (D.G.); (M.T.); (L.B.); (L.D.A.)
| |
Collapse
|
7
|
Schmid F, Barrett MJP, Obrist D, Weber B, Jenny P. Red blood cells stabilize flow in brain microvascular networks. PLoS Comput Biol 2019; 15:e1007231. [PMID: 31469820 PMCID: PMC6750893 DOI: 10.1371/journal.pcbi.1007231] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 09/18/2019] [Accepted: 07/01/2019] [Indexed: 12/28/2022] Open
Abstract
Capillaries are the prime location for oxygen and nutrient exchange in all tissues. Despite their fundamental role, our knowledge of perfusion and flow regulation in cortical capillary beds is still limited. Here, we use in vivo measurements and blood flow simulations in anatomically accurate microvascular network to investigate the impact of red blood cells (RBCs) on microvascular flow. Based on these in vivo and in silico experiments, we show that the impact of RBCs leads to a bias toward equating the values of the outflow velocities at divergent capillary bifurcations, for which we coin the term “well-balanced bifurcations”. Our simulation results further reveal that hematocrit heterogeneity is directly caused by the RBC dynamics, i.e. by their unequal partitioning at bifurcations and their effect on vessel resistance. These results provide the first in vivo evidence of the impact of RBC dynamics on the flow field in the cortical microvasculature. By structural and functional analyses of our blood flow simulations we show that capillary diameter changes locally alter flow and RBC distribution. A dilation of 10% along a vessel length of 100 μm increases the flow on average by 21% in the dilated vessel downstream a well-balanced bifurcation. The number of RBCs rises on average by 27%. Importantly, RBC up-regulation proves to be more effective the more balanced the outflow velocities at the upstream bifurcation are. Taken together, we conclude that diameter changes at capillary level bear potential to locally change the flow field and the RBC distribution. Moreover, our results suggest that the balancing of outflow velocities contributes to the robustness of perfusion. Based on our in silico results, we anticipate that the bi-phasic nature of blood and small-scale regulations are essential for a well-adjusted oxygen and energy substrate supply. Glucose and oxygen are key energy sources of the brain. As energy storage capabilities are limited in the brain, a continuous supply of oxygen and glucose via the bloodstream is crucial for the brain’s functioning. The bulk of discharge occurs at the level of capillaries, which are the smallest and most frequent vessels of the cortical vasculature. Nonetheless, our understanding of perfusion and topology of the capillary bed is still limited. Here, we use in vivo two-photon based blood flow measurements and numerical simulations in large realistic microvascular networks to study the flow in the cortical microvasculature. Our results reveal that the impact of red blood cells enhances the robustness of microvascular perfusion and increases the heterogeneity in red blood cell distribution. It is well established that higher neuronal activity leads to an increase in blood flow. However, the precise regulation mechanisms and their spatial extent remain largely unknown. We show that small-scale regulations locally alter flow and red blood cell distribution. We suggest that these mechanisms are key for an efficient and flexible circulatory system. Moreover, our results reveal a novel role of the bi-phasic nature of blood.
Collapse
Affiliation(s)
- Franca Schmid
- Institute of Fluid Dynamics, ETH Zurich, Sonneggstrasse 3, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
- * E-mail:
| | - Matthew J. P. Barrett
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Dominik Obrist
- ARTORG Center for Biomedical Engineering Research, University of Bern, Murtenstrasse 50, Bern, Switzerland
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Patrick Jenny
- Institute of Fluid Dynamics, ETH Zurich, Sonneggstrasse 3, Zurich, Switzerland
| |
Collapse
|
8
|
Chu Z, Zhou H, Cheng Y, Zhang Q, Wang RK. Improving visualization and quantitative assessment of choriocapillaris with swept source OCTA through registration and averaging applicable to clinical systems. Sci Rep 2018; 8:16826. [PMID: 30429502 PMCID: PMC6235855 DOI: 10.1038/s41598-018-34826-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/24/2018] [Indexed: 12/25/2022] Open
Abstract
Choriocapillaris (CC) visualization and quantification remains challenging. We propose an innovative three-step registration and averaging approach using repeated swept source optical coherence tomography angiography (SS-OCTA) scans to conduct automatic quantitative assessment on CC. Six subjects were enrolled, each imaged at several locations with SS-OCTA from macular to equatorial regions using 3 mm × 3 mm scanning pattern. Five repeated volumes were collected for each subject. The complex optical microangiography (OMAG) algorithm was applied to identify blood flow in CC slab. An automatic three-step registration of translation, affine and B-Spline was applied to en face OCTA images of CC, followed with averaging. A fuzzy clustering approach was used to segment vasculature and flow deficits from the averaged images. The improvement in visualization of CC was evaluated and the average intercapillary distance was estimated by calculating the averaged capillary lumen spacing. A series of quantitative indices of flow deficit density, number, size, complexity index and aspect ratio index (FDD, FDN, FDS, FDCI and FDARI) were designed and validated with the increase of repeated scan numbers for averaging. Quantitative assessment was applied and compared on CC in macular and equatorial regions. The intercapillary distance was observed to be around 24 µm at macula and increased toward equatorial regions. All five quantitative indices (FDD, FDN, FDS, FDCI and FDARI) showed significant changes with multiple averaging and tend to become stable with repeated number of 4. Our proposed registration and averaging algorithm significantly improved the visualization of CC with SS-OCTA. The designed five indices for CC provide more options in the quantitative assessment of CC and are of great potentials in assisting the understanding of disease pathology, early diagnosis and treatment monitoring.
Collapse
Affiliation(s)
- Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Hao Zhou
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Yuxuan Cheng
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA.
| |
Collapse
|
9
|
Nesper PL, Fawzi AA. Human Parafoveal Capillary Vascular Anatomy and Connectivity Revealed by Optical Coherence Tomography Angiography. Invest Ophthalmol Vis Sci 2018; 59:3858-3867. [PMID: 30073360 PMCID: PMC6071478 DOI: 10.1167/iovs.18-24710] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/07/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the connection among arterioles, venules, and capillaries in three retinal capillary plexuses using optical coherence tomography angiography (OCTA). Methods This was a prospective, cross-sectional, observational study including 20 eyes of 10 healthy subjects. En face and cross-sectional OCTA images were segmented to study the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP). Using thin slabs and manual segmentation within the three plexuses, we examined the connections between the large-caliber superficial vessels within a 3 × 3 mm2 OCTA scan (arterioles and venules) and the smaller capillaries in each plexus. Results Twenty eyes of 10 healthy subjects (5 females; average age of 30.8 ± 6.3 years) were included in the analysis. We identified vascular interconnections linking the superficial arterioles and venules with capillaries in each plexus (SCP, MCP, and DCP). We found capillaries in the DCP crossed the horizontal raphe. Conclusions Our findings show that each of the three capillary plexuses in the parafovea has its own feeding arteriolar supply and draining venules, supporting a physiologic model in which each plexus controls its own oxygenated blood supply to match the metabolic needs of each distinct retinal neurovascular unit.
Collapse
Affiliation(s)
- Peter L. Nesper
- The Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Amani A. Fawzi
- The Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| |
Collapse
|
10
|
Balaratnasingam C, An D, Sakurada Y, Lee CS, Lee AY, McAllister IL, Freund KB, Sarunic M, Yu DY. Comparisons Between Histology and Optical Coherence Tomography Angiography of the Periarterial Capillary-Free Zone. Am J Ophthalmol 2018; 189:55-64. [PMID: 29470970 DOI: 10.1016/j.ajo.2018.02.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 02/10/2018] [Accepted: 02/11/2018] [Indexed: 12/27/2022]
Abstract
PURPOSE To use the capillary-free zone along retinal arteries, a physiologic area of superficial avascularization, as an anatomic paradigm to investigate the reliability of optical coherence tomography angiography (OCTA) for visualizing the deep retinal circulation. DESIGN Validity analysis and laboratory investigation. METHODS Five normal human donor eyes (mean age 69.8 years) were perfusion-labeled with endothelial antibodies and the capillary networks of the perifovea were visualized using confocal scanning laser microscopy. Regions of the capillary-free zone along the retinal artery were imaged using OCTA in 16 normal subjects (age range 24-51 years). Then, 3 × 3-mm scans were acquired using the RTVue XR Avanti (ver. 2016.1.0.26; Optovue, Inc, Fremont, California, USA), PLEX Elite 9000 (ver. 1.5.0.15909; Zeiss Meditec, Inc, Dublin, California, USA), Heidelberg Spectralis OCT2 (Family acquisition module 6.7.21.0; Heidelberg Engineering, Heidelberg, Germany), and DRI-OCT Triton (Ver. 1.1.1; Topcon Corp, Tokyo, Japan). Images of the superficial plexus, deep vascular plexus, and a slab containing all vascular plexuses were generated using manufacturer-recommended default settings. Comparisons between histology and OCTA were performed. RESULTS Histologic analysis revealed that the capillary-free zone along the retinal artery was confined to the plane of the superficial capillary plexus and did not include the intermediate and deep capillary plexuses. Images derived from OCTA instruments demonstrated a prominent capillary-free zone along the retinal artery in slabs of the superficial plexus, deep plexus, and all capillary plexuses. The number of deep retinal capillaries seen in the capillary-free zone was significantly greater on histology than on OCTA (P < .001). CONCLUSION Using the capillary-free zone as an anatomic paradigm, we show that the deep vascular beds of the retina are not completely visualized using OCTA. This may be a limitation of current OCTA techniques.
Collapse
Affiliation(s)
- Chandrakumar Balaratnasingam
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia; Department of Ophthalmology, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Dong An
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia
| | - Yoichi Sakurada
- LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear and Throat Hospital, New York, New York; Department of Ophthalmology, University of Yamanashi, Yamanashi, Japan
| | - Cecilia S Lee
- Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Aaron Y Lee
- Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Ian L McAllister
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, Australia
| | - K Bailey Freund
- LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear and Throat Hospital, New York, New York; Vitreous, Retina, Macula Consultants of New York, New York; Department of Ophthalmology, New York University School of Medicine, New York, New York
| | - Marinko Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia.
| |
Collapse
|
11
|
Weber R, Silver A, Williams SJ, Stephenson L, Usera PC, Zhang F, Tian H, Yang W, Wang WZ, Fang XH, Zamboni WA, Baynosa R. Random flap survival with hyperbaric oxygen: daily versus twice-daily treatments. Undersea Hyperb Med 2018; 45:157-164. [PMID: 29734567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
PURPOSE Hyperbaric oxygen (HBO₂) therapy is used to improve the survival of compromised flaps. Compromised flaps are complications encountered postsurgically, or in traumatic degloving or avulsion injuries. Failed flaps lead to persistence of the defect, requirement of another donor site, and psychosocial sequelae. Although evidence of the benefit of HBO₂ therapy is significant, there is no consensus on the optimal treatment regimen. The purpose of this study is to examine whether twice-daily treatments (BID HBO₂) provide additional benefit compared to daily treatments (QD HBO₂) in a rat compromised random flap model. METHODS A rat random flap model was used with subjects divided into three groups: 1) control group; 2) QD HBO₂; and 3) BID HBO₂, where HBO₂ was performed with 100% oxygen at 2.5 atmospheres absolute/ATA (253 kPa) for 90 minutes. After 10 days, areas of flap necrosis were measured and biopsies were taken for histologic analysis. Statistical analysis was performed using ANOVA and paired t-tests. A P-value ⟨0.05 was considered significant. RESULT Both treatment groups had significantly increased mean flap survival compared to controls (P⟨0.05). There was no significant difference in flap survival between the QD and BID groups. Capillary proliferation in the QD group was increased compared with controls. CONCLUSION Both QD and BID HBO₂ protocols can significantly decrease random flap necrosis. However, the results of this study suggest there is no additional benefit gained with BID treatments. Clinical studies are warranted to confirm these findings and assist in formalization of protocols for the use of HBO₂in treating compromised random flaps.
Collapse
Affiliation(s)
- Rachel Weber
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Andrew Silver
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Shelley J Williams
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Linda Stephenson
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Phillip C Usera
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Fan Zhang
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Honglin Tian
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Wei Yang
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Wei Z Wang
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Xin Hua Fang
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - William A Zamboni
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| | - Richard Baynosa
- UNLV School of Medicine, Division of Plastic Surgery, Las Vegas, Nevada, U.S
| |
Collapse
|
12
|
Steiniger BS, Ulrich C, Berthold M, Guthe M, Lobachev O. Capillary networks and follicular marginal zones in human spleens. Three-dimensional models based on immunostained serial sections. PLoS One 2018; 13:e0191019. [PMID: 29420557 PMCID: PMC5805169 DOI: 10.1371/journal.pone.0191019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 12/27/2017] [Indexed: 12/21/2022] Open
Abstract
We have reconstructed small parts of capillary networks in the human splenic white pulp using serial sections immunostained for CD34 alone or for CD34 and CD271. The three-dimensional (3D) models show three types of interconnected networks: a network with very few long capillaries inside the white pulp originating from central arteries, a denser network surrounding follicles plus periarterial T-cell regions and a network in the red pulp. Capillaries of the perifollicular network and the red pulp network have open ends. Perifollicular capillaries form an arrangement similar to a basketball net located in the outer marginal zone. The marginal zone is defined by MAdCAM-1+ marginal reticular stromal cells. Perifollicular capillaries are connected to red pulp capillaries surrounded by CD271+ stromal capillary sheath cells. The scarcity of capillaries inside the splenic white pulp is astonishing, as non-polarised germinal centres with proliferating B-cells occur in adult human spleens. We suggest that specialized stromal marginal reticular cells form a barrier inside the splenic marginal zone, which together with the scarcity of capillaries guarantees the maintenance of gradients necessary for positioning of migratory B- and T-lymphocytes in the human splenic white pulp.
Collapse
Affiliation(s)
- Birte S. Steiniger
- Institute of Anatomy and Cell Biology, University of Marburg, Marburg, Germany
| | - Christine Ulrich
- Institute of Psychology, University of Marburg, Marburg, Germany
| | - Moritz Berthold
- Institute of Computer Sciences, University of Bayreuth, Bayreuth, Germany
| | - Michael Guthe
- Institute of Computer Sciences, University of Bayreuth, Bayreuth, Germany
| | - Oleg Lobachev
- Institute of Computer Sciences, University of Bayreuth, Bayreuth, Germany
| |
Collapse
|
13
|
Abstract
Previous studies have concluded that microparticles (MPs) can more effectively approach the microvessel wall than nanoparticles because of margination. In this study, however, we show that MPs are not marginated in capillaries where the vessel diameter is comparable to that of red blood cells (RBCs). We numerically investigated the behavior of MPs with a diameter of 1 μm in various microvessel sizes, including capillaries. In capillaries, the flow mode of RBCs shifted from multi-file flow to bolus (single-file) flow, and MPs were captured by the bolus flow of the RBCs instead of being marginated. Once MPs were captured, they rarely escaped from the vortex-like flow structures between RBCs. These capture events were enhanced when the hematocrit was decreased, and reduced when the shear rate was increased. Our results suggest that microparticles may be rather inefficient drug carriers when targeting capillaries because of capture events, but nanoparticles, which are more randomly distributed in capillaries, may be more effective carriers.
Collapse
Affiliation(s)
- Naoki Takeishi
- Institute for Frontier Life and Medical Sciences, Kyoto University, Department of Biosystems Science, 53 Shogoin-Kawara-cho, Sakyo, Kyoto, 606-8507, Japan
| | - Yohsuke Imai
- School of Engineering, Tohoku University, 6-6-01 Aoba, Aoba, Sendai, 980-8579, Japan.
| |
Collapse
|
14
|
Hayashi M, Li TS, Ito H, Mikamo A, Hamano K. Comparison of Intramyocardial and Intravenous Routes of Delivering Bone Marrow Cells for the Treatment of Ischemic Heart Disease: An Experimental Study. Cell Transplant 2017; 13:639-47. [PMID: 15648734 DOI: 10.3727/000000004783983558] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The implantation of bone marrow cells (BMCs) into ischemic heart after myocardial infarction can induce angiogenesis and improve heart function. We compared the advantages of delivering BMCs intramyocardially and intravenously. An acute myocardial infarction model was created by the ligation of left anterior descending artery in female Dark Agouti rats. The rats were then randomly divided into four treatment groups: one given an intramyocardial injection of phosphate-buffered saline (PBS group), one given an intravenous injection of 2 × 107 BMCs from male rats (IV group), one given an intramyocardial injection with total of 2 × 107 BMCs from male rats at four points in the infarction area (IM group), and one given an intravenous injection of 10-fold the number of BMCs from male rats (10xIV group). Quantitative analysis of the SRY gene by real-time PCR showed that the survival of BMCs in the infarcted area was significantly higher in the IM group than in the IV and 10xIV groups, 3 days after treatment (p < 0.05), but not thereafter. However, the blood flow in the infarcted myocardium was significantly better in the IM and 10xIV groups than in the PBS and IV groups 14 days after treatment (p < 0.05). Echocardiography showed that the LVEF continued to decrease in the PBS and IV groups, but was stable after 3 days in the IM and 10xIV groups. By 14 days after treatment, the LVEF was significantly higher in the IM and 10xIV groups than in the PBS and IV groups (p < 0.01). Our results showed that BMCs were more effective delivered intramyocardially than intravenously for inducing angiogenesis and repairing injured myocardium.
Collapse
Affiliation(s)
- Masanori Hayashi
- Division of Cardiovascular Surgery, Department of Medical Bioregulation, Yamaguchi University School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi, Japan 755-8505
| | | | | | | | | |
Collapse
|
15
|
Komlosh ME, Benjamini D, Barnett AS, Schram V, Horkay F, Avram AV, Basser PJ. Anisotropic phantom to calibrate high-q diffusion MRI methods. J Magn Reson 2017; 275:19-28. [PMID: 27951427 PMCID: PMC5325680 DOI: 10.1016/j.jmr.2016.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/29/2016] [Accepted: 11/29/2016] [Indexed: 05/30/2023]
Abstract
A silicon oil-filled glass capillary array is proposed as an anisotropic diffusion MRI phantom. Together with a computational/theoretical pipeline these provide a gold standard for calibrating and validating high-q diffusion MRI experiments. The phantom was used to test high angular resolution diffusion imaging (HARDI) and double pulsed-field gradient (d-PFG) MRI acquisition schemes. MRI-based predictions of microcapillary diameter using both acquisition schemes were compared with results from optical microscopy. This phantom design can be used for quality control and quality assurance purposes and for testing and validating proposed microstructure imaging experiments and the processing pipelines used to analyze them.
Collapse
Affiliation(s)
- M E Komlosh
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; Center for Neuroscience and Regenerative Medicine, The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, MD, USA.
| | - D Benjamini
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - A S Barnett
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - V Schram
- Microscopy and Imaging Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - F Horkay
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - A V Avram
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - P J Basser
- Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
16
|
Al Masri S, Kattanek M, Richardson KC, Hafez HM, Plendl J, Hünigen H. Comparative Quantitative Studies on the Microvasculature of the Heart of a Highly Selected Meat-Type and a Wild-Type Turkey Line. PLoS One 2017; 12:e0170858. [PMID: 28118415 PMCID: PMC5261739 DOI: 10.1371/journal.pone.0170858] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/11/2017] [Indexed: 11/18/2022] Open
Abstract
In this study the macroscopic and microscopic structure of the heart of a fast growing, meat-type turkey line (British United turkeys BUT Big 6) and a wild-type turkey line (Canadian Wild turkey) were compared. At 8 and 16 weeks of age, 10 birds of each genotype and sex were sampled. The body mass and heart mass of the meat-type turkey both increased at a faster rate than those of the wild-type turkey. However in both turkey lines, the relative heart mass decreased slightly with age, the decrease was statistically significant only in the male turkeys. Furthermore meat-type turkeys had a significantly (p < 0.01) lower relative heart mass and relative thickness of the left ventricle compared to the wild-type turkeys of the same age. The wild-type turkeys showed no significant change in the size of cardiomyocytes (cross sectional area and diameter) from 8 weeks to 16 weeks. In contrast, the size of cardiomyocytes increased significantly (p < 0.001) with age in the meat-type turkeys. The number of capillaries in the left ventricular wall increased significantly (p < 0.001) in wild-type turkeys from 2351 per mm2 at the age of 8 weeks to 2843 per mm2 at 16 weeks. However, in the meat-type turkeys there were no significant changes, capillary numbers being 2989 per mm2 at age 8 weeks and 2915 per mm2 at age 16 weeks. Correspondingly the area occupied by capillaries in the myocardium increased in wild-type turkeys from 8.59% at the age of 8 weeks to 9.15% at 16 weeks, whereas in meat-type turkeys this area decreased from 10.4% at 8 weeks to 9.95% at 16 weeks. Our results indicate a mismatch in development between body mass and heart mass and a compromised cardiac capillary density and architecture in the meat-type turkeys in comparison to the wild-type turkeys.
Collapse
Affiliation(s)
- Salah Al Masri
- Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
| | - Maria Kattanek
- Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Kenneth C. Richardson
- College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Hafez Mohamed Hafez
- Institute of Poultry Diseases, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Johanna Plendl
- Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Hana Hünigen
- Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
17
|
Piotto DP, Sekiyama J, Kayser C, Yamada M, Len CA, Terreri MT. Nailfold videocapillaroscopy in healthy children and adolescents: description of normal patterns. Clin Exp Rheumatol 2016; 34 Suppl 100:193-199. [PMID: 26940067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVES to describe normal patterns of nailfold videocapillaroscopy (NVC) in healthy children and adolescents; to quantify the relationship between age and capillary dimensions, intercapillary distance and number of capillaries/mm; to evaluate the inter and intraobserver concordance. METHODS Cross-sectional study including 100 healthy participants aged 5 to 18 years. Capillary dimensions (capillary loop length, capillary width and intercapillary distance) and number of capillaries/mm were evaluated in 900 capillaries using stereomicroscope under 100x magnification. Intra and inter observer agreements were tested. RESULTS The capillary dimensions (mean ± SD) were: capillary loop length 278.6±60.3 μm, intercapillary distance 124.1±28.1 μm, capillary width 15.0±2.6 μm. Teenagers between 15 and 18 years had longer and more enlarged capillaries than the other age groups (p<0.001 and p=0.012 respectively). We also found a significant increase in the number of capillaries/mm with age (p<0.001). There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width (p<0.001, R=0.796; p<0.001, R=0.368; p=0.004, R=0.285, respectively). There was a good intra and interobserver concordance. Enlarged capillary and avascular areas were present in 11% and 10% of capillaries respectively. A weak negative correlation was found between the intercapillary distance and the number of capillaries/mm (p=0.05; R=-0.20). CONCLUSIONS There is a wide variability in the capillary morphology among healthy individuals. There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width. In addition, NVC has been shown to be a reproducible method.
Collapse
Affiliation(s)
- Daniela P Piotto
- Division of Paediatric Rheumatology, Department of Paediatrics, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Juliana Sekiyama
- Division of Rheumatology, Department of Medicine, Universidade de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Cristiane Kayser
- Division of Rheumatology, Department of Medicine, UNIFESP, Sao Paulo, SP, Brazil
| | - Mariana Yamada
- Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Claudio A Len
- Division of Paediatric Rheumatology, Department of Paediatrics, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Maria T Terreri
- Division of Paediatric Rheumatology, Department of Paediatrics, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
| |
Collapse
|
18
|
Zaman A, Ali N, Sajid M, Hayat T. Numerical and Analytical Study of Two-Layered Unsteady Blood Flow through Catheterized Artery. PLoS One 2016; 11:e0161377. [PMID: 27548476 PMCID: PMC4993475 DOI: 10.1371/journal.pone.0161377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 08/04/2016] [Indexed: 11/19/2022] Open
Abstract
The pulsatile flow of blood in a catheterized blood vessel is analyzed. The flow of blood in vessel is modeled as the flow of two immiscible fluids. The fluid in the core region is characterized as a non-Newtonian viscoelastic fluid satisfying the constitutive equation of an Oldroyd-B fluid. The fluid in the peripheral region is treated as a Newtonian fluid. The catheter inside the vessel is modeled as a rigid tube of very small radius. The resulting differential system for velocity in each region is computed numerically by finite-difference scheme and analytically by Laplace transform. A comparison of numerical solution with Laplace transform solution is carried out. Various physical quantities of interest through the computed velocity are also analyzed.
Collapse
Affiliation(s)
- Akbar Zaman
- Department of Mathematics and Statistics, Faculty of Basic and Applied Sciences, International Islamic University, Islamabad, 44000, Pakistan
| | - Nasir Ali
- Department of Mathematics and Statistics, Faculty of Basic and Applied Sciences, International Islamic University, Islamabad, 44000, Pakistan
| | - M. Sajid
- Department of Mathematics and Statistics, Faculty of Basic and Applied Sciences, International Islamic University, Islamabad, 44000, Pakistan
| | - Tasawar Hayat
- Department of Mathematics, Quaid-I-Azam University, Islamabad, 4400, Pakistan
- Nonlinear Analysis and applied Mathematics (NAAM) Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| |
Collapse
|
19
|
|
20
|
Shahlaee A, Samara WA, Hsu J, Say EAT, Khan MA, Sridhar J, Hong BK, Shields CL, Ho AC. In Vivo Assessment of Macular Vascular Density in Healthy Human Eyes Using Optical Coherence Tomography Angiography. Am J Ophthalmol 2016; 165:39-46. [PMID: 26921803 DOI: 10.1016/j.ajo.2016.02.018] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 12/29/2022]
Abstract
PURPOSE To quantify density of macular vascular networks over regions of interest in healthy subjects using optical coherence tomography angiography (OCTA). DESIGN Prospective cross-sectional study. METHODS Setting was the Retina and Oncology Services of Wills Eye Hospital. Subjects with no known systemic disease and without retinal pathology were included. OCTA was performed on a 3 × 3-mm region centered on the macula and en face angiograms of the superficial and deep vascular networks were acquired. Vascular density was calculated using an automated image thresholding method over regions of interest. Foveal and parafoveal vascular density were calculated. The differences between vascular networks, sexes, and fellow eyes and correlation between vascular density, signal strength, and age, as well as reproducibility of measurements, were evaluated. RESULTS A total of 198 healthy eyes were imaged, from which 163 eyes of 122 subjects were included based on image quality criteria. In the parafoveal region, deep vascular density was significantly higher than the superficial (52% ± 2.4% vs 46% ± 2.2%; P < .001), whereas the opposite was found in the foveal region (27% ± 5.2% vs 32% ± 3.2%; P < .001). All vascular density measurements were statistically similar in fellow eyes and there was no sex difference (P > .05). There was a negative correlation between vascular density and age that persisted upon adjusting for signal strength. Vascular density measurements were highly correlated between separate imaging sessions with intraclass correlation coefficients of over 0.85 for all assessments. CONCLUSIONS Calculation of vascular density using OCTA is a reproducible and noninvasive method to quantitate individual networks within the macula. Understanding normal values and their correlations could affect clinical evaluation of the macula in healthy patients and disease states.
Collapse
Affiliation(s)
- Abtin Shahlaee
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Wasim A Samara
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jason Hsu
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Emil Anthony T Say
- Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - M Ali Khan
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jayanth Sridhar
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Bryan K Hong
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Carol L Shields
- Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Allen C Ho
- Retina Service of Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania.
| |
Collapse
|
21
|
Abstract
With increasing age, the kidney undergoes characteristic changes in the glomerular and tubulo-interstitial compartments, which are ultimately accompanied by reduced kidney function. Studies have shown age-related loss of peritubular vessels. Normal peritubular vessel tone, function and survival depend on neighboring pericytes. Pericyte detachment leads to vascular damage, which can be accompanied by their differentiation to fibroblasts and myofibroblasts, a state that favors matrix production. To better understand the fate of pericytes in the aged kidney, 27 month-old mice were studied. Compared to 3 month-old young adult mice, aged kidneys showed a substantial decrease in capillaries, identified by CD31 staining, in both cortex and medulla. This was accompanied by a marked decrease in surrounding NG2+ / PDGFRβ+ pericytes. This decrease was more pronounced in the medulla. Capillaries devoid of pericytes were typically dilated in aged mice. Aged kidneys were also characterized by interstitial fibrosis due to increased collagen-I and -III staining. This was accompanied by an increase in the number of pericytes that acquired a pro-fibrotic phenotype, identified by increased PDGFRβ+ / αSMA+ staining. These findings are consistent with the decline in kidney interstitial pericytes as a critical step in the development of changes to the peritubular vasculature with aging, and accompanying fibrosis.
Collapse
Affiliation(s)
- Ania Stefanska
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Diana Eng
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Natalya Kaverina
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Jeremy S. Duffield
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Biogen Idec, Cambridge, MA 02142, USA
| | - Jeffrey W. Pippin
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Peter Rabinovitch
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | - Stuart J. Shankland
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| |
Collapse
|
22
|
Matsunaga D, Yi J, Puliafito CA, Kashani AH. OCT angiography in healthy human subjects. Ophthalmic Surg Lasers Imaging Retina 2015; 45:510-5. [PMID: 25423629 DOI: 10.3928/23258160-20141118-04] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/07/2014] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND OBJECTIVE To noninvasively evaluate the retinal microvasculature in healthy human subjects with optical coherence tomography angiography (OCTA). PATIENTS AND METHODS Cross-sectional, observational study of five healthy subjects. OCTA was performed on 3 × 3 mm(2) sections centered on the fovea, nasal macula, and temporal macula. Retinal vasculature was assessed within three horizontal slabs consisting of the inner, middle, and outer retina. The vasculature within each retinal slab was reconstructed using phase-based and intensity contrast-based algorithms and visualized as separate en face images. RESULTS OCTA in healthy subjects demonstrates capillary networks consistent with previous histological studies. No retinal vessels were found in the outer retina. OCT angiography of the inner and middle retinal layers showed region-specific vascular patterns that consistently corroborated qualitative findings from past histological studies. CONCLUSION OCTA generates high-resolution, noninvasive angiograms qualitatively similar to conventional fluorescein angiography. OCTA may serve as a bridge to assess some features of the retinal microvasculature between conventionally performed angiograms.
Collapse
|
23
|
Unekawa M, Tomita Y, Toriumi H, Osada T, Masamoto K, Kawaguchi H, Itoh Y, Kanno I, Suzuki N. Hyperperfusion counteracted by transient rapid vasoconstriction followed by long-lasting oligemia induced by cortical spreading depression in anesthetized mice. J Cereb Blood Flow Metab 2015; 35:689-98. [PMID: 25586145 PMCID: PMC4420891 DOI: 10.1038/jcbfm.2014.250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/29/2014] [Accepted: 12/11/2014] [Indexed: 11/09/2022]
Abstract
Cortical spreading depression (CSD) involves mass depolarization of neurons and glial cells accompanied with changes in regional cerebral blood flow (rCBF) and energy metabolism. To further understand the mechanisms of CBF response, we examined the temporal diametric changes in pial arteries, pial veins, and cortical capillaries. In urethane-anesthetized mice, the diameters of these vessels were measured while simultaneously recording rCBF with a laser Doppler flowmeter. We observed a considerable increase in rCBF during depolarization in CSD induced by application of KCl, accompanied by a transient dip of rCBF with marked vasoconstriction of pial arteries, which resembled the response to pin-prick-induced CSD. Arterial constriction diminished or disappeared during the second and third passages of CSD, whereas the rCBF increase was maintained without a transient dip. Long-lasting oligemia with a decrease in the reciprocal of mean transit time of injected dye and mild constriction of pial arteries was observed after several passages of the CSD wave. These results indicate that CSD-induced rCBF changes consist of initial hyperemia with a transient dip and followed by a long-lasting oligemia, partially corresponding to the diametric changes of pial arteries, and further suggest that vessels other than pial arteries, such as intracortical vessels, are involved.
Collapse
Affiliation(s)
- Miyuki Unekawa
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Yutaka Tomita
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Haruki Toriumi
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Takashi Osada
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo, Japan
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Hiroshi Kawaguchi
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Yoshiaki Itoh
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Iwao Kanno
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Norihiro Suzuki
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| |
Collapse
|
24
|
Xu S, Wei Q, Fan Y, Chen S, Liu Q, Yin G, Liao M, Sun Y. [Effect of microneedle combined with Lauromacrogol on skin capillary network: experimental study]. Zhonghua Zheng Xing Wai Ke Za Zhi 2014; 30:448-451. [PMID: 25895301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To explore the effect of microneedle combined with Lauromacrogol on skin capillary network. METHODS 24 male Leghone (1.5-2.0 kg in weight) were randomly divided into three groups as group A (microneedle combined with Lauromacrogol), B (microneedle combined with physiological saline) , and C(control). The cockscombs were treated. The specimens were taken on the 7th, 14th, 21th , and 28th day postoperatively. HE staining, immunohistochemical staining and special staining were performed for study of the number of capillary and collagen I/III , as well as elastic fibers. RESULTS The color of cockscombs in group A became lightening after treatment. The number of capillary decreased as showing by HE staining. The collagen I and III in group B was significantly different from that in group A and C (P < 0.05). Special staining showed proliferation of elastic fibers in group B. CONCLUSIONS It indicates that microneedle combined with Lauromacrogol could effectively reduce the capillary in cockscomb without any tissue fibrosis. Microneedle can stimulate the proliferation of elastic fiber, so as to improve the skin ageing process.
Collapse
|
25
|
Jian W, Duangjinda M, Vajrabukka C, Katawatin S. Differences of skin morphology in Bos indicus, Bos taurus, and their crossbreds. Int J Biometeorol 2014; 58:1087-1094. [PMID: 23824223 DOI: 10.1007/s00484-013-0700-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 06/14/2013] [Accepted: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Cutaneous evaporation is the main avenue by which cattle dissipate heat via the involvement of sweat glands and other skin components. The difference in skin morphology between B. indicus and B. taurus has been recognized, as well as differences in their ability to tolerate heat. The objective of this study was to compare skin morphology between B. indicus, B. taurus, and their crossbreds. Skin samples of Sahiwal (B. indicus) (n=10, reddish brown skin) and Holstein Friesian (HF) (B. taurus) (n=10, black and white skin) and crossbred of HF75% (n=10, black and white skin) and HF87.5 % (n=10, black and white skin) were biopsied for histological study, followed by measurement of skin components. The results indicated that breed significantly affected sweat gland morphology. The shape of the sweat gland, as indicated by the ratio of length/diameter, in Sahiwal was baggier in shape compared to HF (5.99 and 9.52) while values for crossbreds were intermediate (7.82, 8.45). The density and volume of sweat glands in Sahiwal (1,058 glands/cm(2); 1.60 μ(3) × 10(-6)) were higher than in HF (920 glands/cm(2); 0.51 μ(3)x10(-6)) and crossbreds, both HF 75 % (709 glands/cm(2); 0.68 μ(3) × 10(-6)) and HF 87.5 % (691 glands/cm(2); 0.61 μ(3) × 10(-6)) respectively. However, capillary surface area was greater for HF (2.07 cm(2)) compared to Sahiwal (1.79 cm(2)); accordingly, the lower genetic fraction of HF in crossbred cattle showed less capillary surface area (1.83 and 1.9 cm(2) for HF75% and HF87.5 %) (P<0.01). Nerve density was not significantly different between Sahiwal and HF but was higher in the crossbred (P<0.01) cattle. Moreover, the effect of skin color (black and white) was evaluated and it was found that there was an interaction (P<0.01) between breed and skin color on the skin components. This study reveals that there are differences in skin morphology among B. indicus, B. taurus and their crossbreds, with these differences being more or less related to the genetic fraction of HF. This may imply that capability for cutaneous evaporative heat loss and tolerance to heat in crossbred cattle could be related to skin morphology.
Collapse
Affiliation(s)
- Wang Jian
- Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand, 40002,
| | | | | | | |
Collapse
|
26
|
Shemesh N, Álvarez GA, Frydman L. Measuring small compartment dimensions by probing diffusion dynamics via Non-uniform Oscillating-Gradient Spin-Echo (NOGSE) NMR. J Magn Reson 2013; 237:49-62. [PMID: 24140623 DOI: 10.1016/j.jmr.2013.09.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/13/2013] [Accepted: 09/14/2013] [Indexed: 05/22/2023]
Abstract
Noninvasive measurements of microstructure in materials, cells, and in biological tissues, constitute a unique capability of gradient-assisted NMR. Diffusion-diffraction MR approaches pioneered by Callaghan demonstrated this ability; Oscillating-Gradient Spin-Echo (OGSE) methodologies tackle the demanding gradient amplitudes required for observing diffraction patterns by utilizing constant-frequency oscillating gradient pairs that probe the diffusion spectrum, D(ω). Here we present a new class of diffusion MR experiments, termed Non-uniform Oscillating-Gradient Spin-Echo (NOGSE), which dynamically probe multiple frequencies of the diffusion spectral density at once, thus affording direct microstructural information on the compartment's dimension. The NOGSE methodology applies N constant-amplitude gradient oscillations; N-1 of these oscillations are spaced by a characteristic time x, followed by a single gradient oscillation characterized by a time y, such that the diffusion dynamics is probed while keeping (N-1)x+y≡TNOGSE constant. These constant-time, fixed-gradient-amplitude, multi-frequency attributes render NOGSE particularly useful for probing small compartment dimensions with relatively weak gradients - alleviating difficulties associated with probing D(ω) frequency-by-frequency or with varying relaxation weightings, as in other diffusion-monitoring experiments. Analytical descriptions of the NOGSE signal are given, and the sequence's ability to extract small compartment sizes with a sensitivity towards length to the sixth power, is demonstrated using a microstructural phantom. Excellent agreement between theory and experiments was evidenced even upon applying weak gradient amplitudes. An MR imaging version of NOGSE was also implemented in ex vivo pig spinal cords and mouse brains, affording maps based on compartment sizes. The effects of size distributions on NOGSE are also briefly analyzed.
Collapse
Affiliation(s)
- Noam Shemesh
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Gonzalo A Álvarez
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lucio Frydman
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
| |
Collapse
|
27
|
Szukiewicz D, Kochanowski J, Mittal TK, Pyzlak M, Szewczyk G, Cendrowski K. CX3CL1 (fractalkine) and TNFα production by perfused human placental lobules under normoxic and hypoxic conditions in vitro: the importance of CX3CR1 signaling. Inflamm Res 2013; 63:179-89. [PMID: 24270813 PMCID: PMC3921448 DOI: 10.1007/s00011-013-0687-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 10/03/2013] [Accepted: 11/06/2013] [Indexed: 11/30/2022] Open
Abstract
Objective
Inflammation and hypoxia activate the fractalkine (CX3CL1) receptor (CX3CR1)-related signaling pathway. Tumor necrosis factor alpha (TNFα) induces CX3CL1, influencing a mechanism of CX3CL1 autoregulation by CX3CR1 expression. We compared spontaneous and lipopolysaccharide (LPS)-induced CX3CL1 and TNFα production by human placenta under normoxic vs. hypoxic conditions, with respect to CX3CR1 expression and its functional status. Methods Placental lobules of term placentae (N = 24) were perfused extracorporeally. CX3CL1 and TNFα concentrations were measured in the perfusion fluid by ELISA. LPS, anti-CX3CR1 antibodies and pirfenidone were used in respective subgroups. After perfusion, CX3CR1 expression was estimated in placental tissue using quantitative immunohistochemistry, and the final results were adjusted for the mean microvascular density. Results The highest increase in CX3CL1 concentration in response to LPS was observed in hypoxia (p < 0.05). Unlike in normoxia, anti-CX3CR1 administration in hypoxia significantly reduced the LPS-evoked response. CX3CR1 expression was augmented by hypoxia and reached 260.9 ± 41 (% ±SEM) of the reference value in normoxia. Positive immunostaining for CX3CR1 corresponded to the vascular endothelium. Pirfenidone inhibited hypoxia + LPS-related increase in TNFα production and prevented the up-regulation of CX3CR1. Conclusion The modulatory influence of TNFα on CX3CR1 expression in hypoxia and CX3CL1/CX3CR1 interaction may serve as a compensatory mechanism to preserve or augment the pro-inflammatory course of intercellular interactions in placental endothelium.
Collapse
Affiliation(s)
- Dariusz Szukiewicz
- Department of General and Experimental Pathology, Second Faculty of Medicine, Medical University of Warsaw, ul. Krakowskie Przedmiescie 26/28, 00-928 Warsaw, Poland
| | - Jan Kochanowski
- Department of Neurology, Second Faculty of Medicine, Medical University of Warsaw, ul. Ceglowska 80, 01-809 Warsaw, Poland
| | - Tarun Kumar Mittal
- Department of Obstetrics and Gynecology, Second Faculty of Medicine, Medical University of Warsaw, ul. Kondratowicza 8, 03-242 Warsaw, Poland
| | - Michal Pyzlak
- Department of General and Experimental Pathology, Second Faculty of Medicine, Medical University of Warsaw, ul. Krakowskie Przedmiescie 26/28, 00-928 Warsaw, Poland
| | - Grzegorz Szewczyk
- Department of General and Experimental Pathology, Second Faculty of Medicine, Medical University of Warsaw, ul. Krakowskie Przedmiescie 26/28, 00-928 Warsaw, Poland
| | - Krzysztof Cendrowski
- Department of Obstetrics and Gynecology, Second Faculty of Medicine, Medical University of Warsaw, ul. Kondratowicza 8, 03-242 Warsaw, Poland
| |
Collapse
|
28
|
Abstract
OBJECTIVES The socio-economic impact from age-related mental decline is escalating. Supplementation of functional foods for sustaining mental health is desirable. We examined the effect of long-term supplementation of complex milk lipid concentrate (CMLc), mixed dairy phospholipids, on memory and associated vascular and neuronal changes in aged rats. METHODS Fisher/Norway Brown rats were used. Two groups of aged rats (24 months) were fed with either gelatin-formulated CMLc or blank gelatin as the control, for 4 months. To determine age-related changes, a young group (5 months) was also fed with blank gelatin. Morris water maze tests were carried out after the supplementation and brain tissues were collected for biological analysis. RESULTS The aged control rats learnt to locate the platform slower than the young control rats during acquisition trials (*P < 0.05), and made fewer entries to and more initial heading errors from the platform zone during testing trials (*P < 0.05). The CMLc supplementation improved memory by showing the reduced initial heading errors in a delayed probe trial ((#)P < 0.05). We also found that the aged rats with CMLc supplementation improved vascular density, dopamine output, and neuroplasticity ((#)P < 0.05) in the brain regions involved in memory compared with that of the aged control rats. DISCUSSION The data suggested that the supplementation of CMLc during the early stage of brain aging may prevent memory decline possibly through improving vascular and neuronal function.
Collapse
|
29
|
Kubínová L, Mao XW, Janáček J. Blood capillary length estimation from three-dimensional microscopic data by image analysis and stereology. Microsc Microanal 2013; 19:898-906. [PMID: 23673308 DOI: 10.1017/s1431927613001487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Studies of the capillary bed characterized by its length or length density are relevant in many biomedical studies. A reliable assessment of capillary length from two-dimensional (2D), thin histological sections is a rather difficult task as it requires physical cutting of such sections in randomized directions. This is often technically demanding, inefficient, or outright impossible. However, if 3D image data of the microscopic structure under investigation are available, methods of length estimation that do not require randomized physical cutting of sections may be applied. Two different rat brain regions were optically sliced by confocal microscopy and resulting 3D images processed by three types of capillary length estimation methods: (1) stereological methods based on a computer generation of isotropic uniform random virtual test probes in 3D, either in the form of spatial grids of virtual "slicer" planes or spherical probes; (2) automatic method employing a digital version of the Crofton relations using the Euler characteristic of planar sections of the binary image; and (3) interactive "tracer" method for length measurement based on a manual delineation in 3D of the axes of capillary segments. The presented methods were compared in terms of their practical applicability, efficiency, and precision.
Collapse
Affiliation(s)
- Lucie Kubínová
- Department of Biomathematics, Institute of Physiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 14220 Prague, Czech Republic.
| | | | | |
Collapse
|
30
|
Jimoh SA, Maina JN. Immuno-localization of type-IV collagen in the blood-gas barrier and the epithelial-epithelial cell connections of the avian lung. Biol Lett 2013; 9:20120951. [PMID: 23193049 PMCID: PMC3565516 DOI: 10.1098/rsbl.2012.0951] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 11/05/2012] [Indexed: 11/12/2022] Open
Abstract
The terminal respiratory units of the gas exchange tissue of the avian lung, the air capillaries (ACs) and the blood capillaries (BCs), are small and rigid: the basis of this mechanical feature has been highly contentious. Because the strength of the blood-gas barrier (BGB) of the mammalian lung has been attributed to the presence of type-IV collagen (T-IVc), localization of T-IVc in the basement membranes (BM) of the BGB and the epithelial-epithelial cell connections (E-ECCs) of the exchange tissue of the lung of the avian (chicken) lung was performed in order to determine whether it may likewise contribute to the strength of the BGB. T-IVc was localized in both the BM and the E-ECCs. As part of an integrated fibroskeletal scaffold on the lung, T-IVc may directly contribute to the strengths of the ACs and the BCs.
Collapse
Affiliation(s)
- S. A. Jimoh
- School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - J. N. Maina
- School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Zoology, University of Johannesburg, Johannesburg, South Africa
| |
Collapse
|
31
|
Issaian T, Urity VB, Dantzler WH, Pannabecker TL. Architecture of vasa recta in the renal inner medulla of the desert rodent Dipodomys merriami: potential impact on the urine concentrating mechanism. Am J Physiol Regul Integr Comp Physiol 2012; 303:R748-56. [PMID: 22914749 PMCID: PMC3469668 DOI: 10.1152/ajpregu.00300.2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 08/21/2012] [Indexed: 11/22/2022]
Abstract
We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to over 6,000 mosmol/kg H(2)O, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary vascular segments in the outer inner medulla were assessed with immunofluorescence and digital reconstructions from tissue sections. Descending vasa recta (DVR) expressing the urea transporter UT-B and the water channel aquaporin 1 lie at the periphery of groups of collecting ducts (CDs) that coalesce in their descent through the inner medulla. Ascending vasa recta (AVR) lie inside and outside groups of CDs. DVR peel away from vascular bundles at a uniform rate as they descend the inner medulla, and feed into networks of AVR that are associated with organized clusters of CDs. These AVR form interstitial nodal spaces, with each space composed of a single CD, two AVR, and one or more ascending thin limbs or prebend segments, an architecture that may lead to solute compartmentation and fluid fluxes essential to the urine concentrating mechanism. Although we have identified several apparent differences, the tubulovascular architecture of the kangaroo rat inner medulla is remarkably similar to that of the Munich Wistar rat at the level of our analyses. More detailed studies are required for identifying interspecies functional differences.
Collapse
Affiliation(s)
- Tadeh Issaian
- Dept. of Physiology, Univ. of Arizona Health Sciences Center, Tucson, AZ 85724-5051, USA
| | | | | | | |
Collapse
|
32
|
Gealekman O, Guseva N, Gurav K, Gusev A, Hartigan C, Thompson M, Malkani S, Corvera S. Effect of rosiglitazone on capillary density and angiogenesis in adipose tissue of normoglycaemic humans in a randomised controlled trial. Diabetologia 2012; 55:2794-2799. [PMID: 22847059 PMCID: PMC3549462 DOI: 10.1007/s00125-012-2658-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 06/08/2012] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS Recent reports of decreased capillary density in the adipose tissue of obese individuals suggest that an imbalance of angiogenesis and adipogenesis may, in part, underlie insulin resistance. This study aimed to determine whether the insulin-sensitising peroxisome proliferator-activated receptor γ (PPARγ) activator rosiglitazone affects adipose tissue vascularisation in normal humans. METHODS A randomised, parallel-group, investigator-blinded placebo-controlled trial was conducted with normoglycaemic volunteers with BMI 27-43, recruited from the community at the University of Massachusetts Medical School, Worcester, MA, USA. Peri-umbilical adipose tissue biopsies were obtained before and after treatment for 6 weeks with rosiglitazone (8 mg once daily) or placebo, which were randomly allocated from a sequentially numbered list. The primary outcomes were adipocyte size and capillary density measured by immunohistochemistry, and angiogenic potential assessed by capillary sprout formation in Matrigel. Secondary outcomes were serum adiponectin, glycaemic, lipid and liver function variables. RESULTS A total of 35 individuals fulfilling the inclusion criteria were randomised, and complete before-vs-after analyses were achieved in 30 participants (13 and 17, placebo and rosiglitazone, respectively). Significant differences, assessed by paired two-tailed Student t tests, were seen in response to rosiglitazone for adipocyte size (3,458 ± 202 vs 2,693 ± 223 μm(2), p = 0.0049), capillary density (5.6 ± 0.5 vs 7.5 ± 0.5 lumens/field, p = 0.0098), serum adiponectin (14.3 ± 1.5 vs 28.6 ± 3.0 ng/ml, p < 0.0001) and alkaline phosphatase (1.04 ± 0.07 vs 0.87 ± 0.05 μkat/l, p = 0.001). A difference in angiogenic potential before and after treatment between the placebo and rosiglitazone groups was also seen (-23.88 ± 14 vs 13.42 ± 13, p = 0.029, two-tailed Mann-Whitney test). CONCLUSIONS/INTERPRETATION Significant effects on adipose tissue vascular architecture occur after a short period of treatment with rosiglitazone in individuals with normal glucose tolerance. Improved adipose tissue vascularisation may, in part, mediate the therapeutic actions of this class of drugs. TRIAL REGISTRATION ClinicalTrials.gov NCT01150981 FUNDING The study was funded by National Institutes of Health grant DK089101 to S. Corvera, and by pilot funding from the University of Massachusetts (UMASS) Center for Clinical Translational Sciences (M. Thompson, S. Malkani and S. Corvera). Morphology core services were supported by UMASS Diabetes Endocrine Research Center (DERC) grant DK32520.
Collapse
Affiliation(s)
- O Gealekman
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01615, USA
| | - N Guseva
- Department of Medicine, University of Massachusetts Medical School, Worcester, USA
| | - K Gurav
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01615, USA
| | - A Gusev
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01615, USA
| | - C Hartigan
- Department of Medicine, University of Massachusetts Medical School, Worcester, USA
| | - M Thompson
- Department of Medicine, University of Massachusetts Medical School, Worcester, USA
| | - S Malkani
- Department of Medicine, University of Massachusetts Medical School, Worcester, USA
| | - S Corvera
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01615, USA.
| |
Collapse
|
33
|
Archid R, Patzelt A, Lange-Asschenfeldt B, Ahmad SS, Ulrich M, Stockfleth E, Philipp S, Sterry W, Lademann J. Confocal laser-scanning microscopy of capillaries in normal and psoriatic skin. J Biomed Opt 2012; 17:101511. [PMID: 23223987 DOI: 10.1117/1.jbo.17.10.101511] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An important and most likely active role in the pathogenesis of psoriasis has been attributed to changes in cutaneous blood vessels. The purpose of this study was to use confocal laser-scanning microscopy (CLSM) to investigate dermal capillaries in psoriatic and normal skin. The structures of the capillary loops in 5 healthy participants were compared with those in affected skin of 13 psoriasis patients. The diameters of the capillaries and papillae were measured for each group with CLSM. All investigated psoriasis patients showed elongated, widened, and tortuous microvessels in the papillary dermis, whereas all healthy controls showed a single capillary loop in each dermal papilla. The capillaries of the papillary loop and the dermal papilla were significantly enlarged in the psoriatic skin lesions (diameters 24.39±2.34 and 146.46±28.52 μm, respectively) in comparison to healthy skin (diameters 9.53±1.8 and 69.48±17.16 μm, respectively) (P<0.001). CLSM appears to represent a promising noninvasive technique for evaluating dermal capillaries in patients with psoriasis. The diameter of the vessels could be seen as a well-quantifiable indicator for the state of psoriatic skin. CLSM could be useful for therapeutic monitoring to delay possible recurrences.
Collapse
Affiliation(s)
- Rami Archid
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology-CCP, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Affiliation(s)
- L Mannerås-Holm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - A Krook
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers Road 4a, 171 77, Stockholm, Sweden.
| |
Collapse
|
35
|
Kurokawa K, Sasaki K, Makita S, Hong YJ, Yasuno Y. Three-dimensional retinal and choroidal capillary imaging by power Doppler optical coherence angiography with adaptive optics. Opt Express 2012; 20:22796-812. [PMID: 23037430 DOI: 10.1364/oe.20.022796] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Retinal and choroidal vascular imaging is a key to the better understanding and diagnosis of eye diseases. To achieve comprehensive three-dimensional capillary imaging, we used an enhanced vascular imaging technique, so called adaptive optics optical coherence angiography (AO-OCA). AO-OCA enables in vivo high-resolution and high-contrast micro-vascular imaging by detecting Doppler frequency shifts. Using this technique, the retinal and choroidal vasculatures of healthy subjects were imaged. The results show that both intensity and Doppler power images have sufficient contrast to discriminate almost all vasculatures from the static tissue. However, the choriocapillaris, pre-arterioles, and post-venules in the Sattler layer were more contrasted by the Doppler technique. In conclusion, AO-OCA enables three-dimensional capillary imaging, and is especially useful for the detection of the choriocapillaris and choroidal capillary network.
Collapse
|
36
|
Chinta LV, Lindvere L, Dorr A, Sahota B, Sled JG, Stefanovic B. Quantitative estimates of stimulation-induced perfusion response using two-photon fluorescence microscopy of cortical microvascular networks. Neuroimage 2012; 61:517-24. [PMID: 22521258 DOI: 10.1016/j.neuroimage.2012.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 03/30/2012] [Accepted: 04/03/2012] [Indexed: 01/29/2023] Open
Abstract
Functional hyperemia, or the increase in focal perfusion elicited by neuronal activation, is one of the primary functions of the neurovascular unit and a hallmark of healthy brain functioning. While much is known about the hemodynamics on the millimeter to tenths of millimeter-scale accessible by MRI, there is a paucity of quantitative data on the micrometer-scale changes in perfusion in response to functional stimulation. We present a novel methodology for quantification of perfusion and intravascular flow across the 3D microvascular network in the rat somatosensory cortex using two-photon fluorescence microscopy (2PFM). For approximately 96% of responding microvessels in the forelimb representation of the primary somatosensory cortex, brief (~2s) forepaw stimulation resulted in an increase of perfusion 20±4% (mean±sem). The perfusion levels associated with the remaining 4% of the responding microvessels decreased 10±9% upon stimulation. Vessels irrigating regions of lower vascular density were found to exhibit higher flow (p<0.02), supporting the notion that local vascular morphology and hemodynamics reflect the metabolic needs of the surrounding parenchyma. High dispersion (~77%) in perfusion levels suggests high spatial variation in tissue susceptibility to hypoxia. The current methodology enables quantification of absolute perfusion associated with individual vessels of the cortical microvascular bed and its changes in response to functional stimulation and thereby provides an important tool for studying the cellular mechanisms of functional hyperemia, the spatial specificity of perfusion response to functional stimulation, and, broadly, the micrometer-scale relationship between vascular morphology and function in health and disease.
Collapse
Affiliation(s)
- Lakshminarayan V Chinta
- Imaging Research, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5
| | | | | | | | | | | |
Collapse
|
37
|
Abstract
Inferring on the geometry of an object from its frequency spectrum is highly appealing since the object could then be imaged noninvasively or from a distance (as famously put by Kac, "can one hear the shape of a drum?"). In nuclear magnetic resonance of porous systems, the shape of the drum is represented by the pore density function that bears all the information on the collective pore microstructure. So far, conventional magnetic resonance imaging (MRI) could only detect the pore autocorrelation function, which inherently obscures fine details on the pore structure. Here, for the first time, we report on a unique imaging mechanism arising from synergistic diffusion-diffractions that directly yields the pore density function. This mechanism offers substantially higher spatial resolution compared to conventional MRI while retaining all fine details on the collective pore morphology. Thus, using these unique synergistic diffusion-diffractions, the "shape of the drum" can be inferred.
Collapse
Affiliation(s)
- Noam Shemesh
- School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
| | | | | |
Collapse
|
38
|
Lang S, Dominietto M, Cattin P, Ulmann-Schuler A, Weitkamp T, Müller B. Global and local hard X-ray tomography of a centimeter-size tumor vessel tree. J Synchrotron Radiat 2012; 19:114-125. [PMID: 22186652 DOI: 10.1107/s0909049511046139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 11/02/2011] [Indexed: 05/31/2023]
Abstract
The visualization of the vascular network in tumors down to the smallest vessels requires high spatial resolution and reasonable contrast. Stained corrosion casts of the microvasculature network guarantee superior X-ray absorption contrast and highest reproduction fidelity. Tomography of a centimeter-size tumor, however, is unfeasible at the spatial resolution needed to reveal the smallest vessels. Therefore, local tomography has been performed to visualize the smallest capillaries within the region of interest. These three-dimensional data show the detailed morphology, but the reconstructed absorption coefficients obtained in local tomography differ substantially from the absorption coefficients retrieved from the less detailed global tomography data. This paper deals with the adaptation of local tomography data using the global data and considers two-parameter histogram matching of the radiographs, sinogram extension, and multi-parameter cupping correction. It is demonstrated that two-parameter histogram matching of the radiographs already provides reasonable agreement. The change of the lens in front of the detector's camera, however, significantly affects the obtained local X-ray absorption coefficients in the tomograms predominantly owing to the dissimilar point-spread functions of the two configurations used, and much less to the fact that one of the data sets was acquired in a local geometry.
Collapse
Affiliation(s)
- Sabrina Lang
- Biomaterials Science Center, University of Basel, Basel, Switzerland
| | | | | | | | | | | |
Collapse
|
39
|
Han SH, Song YK, Cho FH, Ryu S, Cho G, Song YQ, Cho H. Magnetic field anisotropy based MR tractography. J Magn Reson 2011; 212:386-393. [PMID: 21875818 DOI: 10.1016/j.jmr.2011.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Revised: 07/19/2011] [Accepted: 07/26/2011] [Indexed: 05/31/2023]
Abstract
Non-invasive measurements of structural orientation provide unique information regarding the connectivity and functionality of fiber materials. In the present study, we use a capillary model to demonstrate that the direction of fiber structure can be obtained from susceptibility-induced magnetic field anisotropy. The interference pattern between internal and external magnetic field gradients carries the signature of the underlying anisotropic structure and can be measured by MRI-based water diffusion measurements. Through both numerical simulation and experiments, we found that this technique can determine the capillary orientation within 3°. Therefore, susceptibility-induced magnetic field anisotropy may be useful for an alternative tractography method when diffusion anisotropy is small at higher magnetic field strength without the need to rotate the subject inside the scanner.
Collapse
Affiliation(s)
- S H Han
- School of Nano-BioScience and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | | | | | | | | | | | | |
Collapse
|
40
|
Jia Y, Qin J, Zhi Z, Wang RK. Ultrahigh sensitive optical microangiography reveals depth-resolved microcirculation and its longitudinal response to prolonged ischemic event within skeletal muscles in mice. J Biomed Opt 2011; 16:086004. [PMID: 21895316 PMCID: PMC3162619 DOI: 10.1117/1.3606565] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The primary pathophysiology of peripheral arterial disease is associated with impaired perfusion to the muscle tissue in the lower extremities. The lack of effective pharmacologic treatments that stimulate vessel collateralization emphasizes the need for an imaging method that can be used to dynamically visualize depth-resolved microcirculation within muscle tissues. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing three-dimensional images of dynamic blood perfusion within microcirculatory tissue beds at an imaging depth of up to ∼2 mm, with an unprecedented imaging sensitivity of blood flow at ∼4 μm∕s. In this paper, we demonstrate the utility of OMAG in imaging the detailed blood flow distributions, at a capillary-level resolution, within skeletal muscles of mice. By use of the mouse model of hind-limb ischemia, we show that OMAG can assess the time-dependent changes in muscle perfusion and perfusion restoration along tissue depth. These findings indicate that OMAG can represent a sensitive, consistent technique to effectively study pharmacologic therapies aimed at promoting the growth and development of collateral vessels.
Collapse
Affiliation(s)
- Yali Jia
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA
| | | | | | | |
Collapse
|
41
|
Abstract
Early in the last century August Krogh embarked on a series of seminal studies to understand the connection between tissue metabolism and mechanisms by which the cardiovascular system supplied oxygen to meet those needs. Krogh recognized that oxygen was supplied from blood to the tissues by passive diffusion and that the most likely site for oxygen exchange was the capillary network. Studies of tissue oxygen consumption and diffusion coefficient, coupled with anatomical studies of capillarity in various tissues, led him to formulate a model of oxygen diffusion from a single capillary. Fifty years after the publication of this work, new methods were developed which allowed the direct measurement of oxygen in and around microvessels. These direct measurements have confirmed the predictions by Krogh and have led to extensions of his ideas resulting in our current understanding of oxygenation within the microcirculation. Developments during the last 40 years are reviewed, including studies of oxygen gradients in arterioles, capillaries, venules, microvessel wall and surrounding tissue. These measurements were made possible by the development and use of new methods to investigate oxygen in the microcirculation, so mention is made of oxygen microelectrodes, microspectrophotometry of haemoglobin and phosphorescence quenching microscopy. Our understanding of oxygen transport from the perspective of the microcirculation has gone from a consideration of oxygen gradients in capillaries and tissue to the realization that oxygen has the ability to diffuse from any microvessel to another location under the conditions that there exists a large enough PO(2) gradient and that the permeability for oxygen along the intervening pathway is sufficient.
Collapse
Affiliation(s)
- R N Pittman
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA.
| |
Collapse
|
42
|
Abstract
The O(2) requirements of contracting skeletal muscle may increase 100-fold above rest. In 1919, August Krogh's brilliant insights recognized the capillary as the principal site for this increased blood-myocyte O(2) flux. Based on the premise that most capillaries did not sustain RBC flux at rest, Krogh proposed that capillary recruitment [i.e. initiation of red blood cell (RBC) flux in previously non-flowing capillaries] increased the capillary surface area available for O(2) flux and reduced mean capillary-to-mitochondrial diffusion distances. More modern experimental approaches reveal that most muscle capillaries may support RBC flux at rest. Thus, rather than contraction-induced capillary recruitment per se, increased RBC flux and haematocrit within already-flowing capillaries probably elevate perfusive and diffusive O(2) conductances and hence blood-myocyte O(2) flux. Additional surface area for O(2) exchange is recruited but, crucially, this may occur along the length of already-flowing capillaries (i.e. longitudinal recruitment). Today, the capillary is still considered the principal site for O(2) and substrate delivery to contracting skeletal muscle. Indeed, the presence of very low intramyocyte O(2) partial pressures (PO(2)s) and the absence of intramyocyte PO(2) gradients, whilst refuting the relevance of diffusion distances, place an even greater importance on capillary hemodynamics. This emergent picture calls for a paradigm-shift in our understanding of the function of capillaries by de-emphasizing de novo'capillary recruitment'. Diseases such as heart failure impair blood-myocyte O(2) flux, in part, by decreasing the proportion of RBC-flowing capillaries. Knowledge of capillary function in healthy muscle is requisite for identification of pathology and efficient design of therapeutic treatments.
Collapse
Affiliation(s)
- D C Poole
- Departments of Kinesiology, Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
| | | | | | | |
Collapse
|
43
|
Abstract
(1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion.
Collapse
Affiliation(s)
- S Egginton
- Department of Physiology, University of Birmingham, Birmingham, UK.
| |
Collapse
|
44
|
Liu G, Qi W, Yu L, Chen Z. Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging. Opt Express 2011; 19:3657-66. [PMID: 21369191 PMCID: PMC3110778 DOI: 10.1364/oe.19.003657] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 01/15/2011] [Accepted: 01/20/2011] [Indexed: 05/17/2023]
Abstract
In this paper, we analyze the retinal and choroidal blood vasculature in the posterior segment of the human eye with optimized color Doppler and Doppler variance optical coherence tomography. Depth-resolved structure, color Doppler and Doppler variance images are compared. Blood vessels down to the capillary level were detected and visualized with the optimized optical coherence color Doppler and Doppler variance method. For in-vivo imaging of human eyes, bulk-motion induced bulk phase must be identified and removed before using the color Doppler method. It was found that the Doppler variance method is not sensitive to bulk-motion and the method can be used without correcting the bulk-motion when the sample-movement-induced velocity changes gradually. Real-time processing and displaying of the structure and blood vessel images are very interesting and is demonstrated using a dual quad-core Central Processing Unit (CPU) workstation. High resolution images of choroidal capillary of the vasculature network with phased-resolved color Doppler and Doppler variance are shown.
Collapse
Affiliation(s)
- Gangjun Liu
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612,
USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92617,
USA
| | - Wenjuan Qi
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612,
USA
| | - Lingfeng Yu
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612,
USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612,
USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92617,
USA
- Dept. of Cogno-Mechatronics Engineering, Pusan National University, Busan,
South Korea
| |
Collapse
|
45
|
Maina JN, Jimoh SA, Hosie M. Implicit mechanistic role of the collagen, smooth muscle, and elastic tissue components in strengthening the air and blood capillaries of the avian lung. J Anat 2010; 217:597-608. [PMID: 20819116 PMCID: PMC3035864 DOI: 10.1111/j.1469-7580.2010.01279.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2010] [Indexed: 11/28/2022] Open
Abstract
To identify the forces that may exist in the parabronchus of the avian lung and that which may explain the reported strengths of the terminal respiratory units, the air capillaries and the blood capillaries, the arrangement of the parabronchial collagen fibers (CF) of the lung of the domestic fowl, Gallus gallus variant domesticus was investigated by discriminatory staining, selective alkali digestion, and vascular casting followed by alkali digestion. On the luminal circumference, the atrial and the infundibular CF are directly connected to the smooth muscle fibers and the elastic tissue fibers. The CF in this part of the parabronchus form the internal column (the axial scaffold), whereas the CF in the interparabronchial septa and those associated with the walls of the interparabronchial blood vessels form the external, i.e. the peripheral, parabronchial CF scaffold. Thin CF penetrate the exchange tissue directly from the interparabronchial septa and indirectly by accompanying the intraparabronchial blood vessels. Forming a dense network that supports the air and blood capillaries, the CF weave through the exchange tissue. The exchange tissue, specifically the air and blood capillaries, is effectively suspended between CF pillars by an intricate system of thin CF, elastic and smooth muscle fibers. The CF course through the basement membranes of the walls of the blood and air capillaries. Based on the architecture of the smooth muscle fibers, the CF, the elastic muscle fibers, and structures like the interparabronchial septa and their associated blood vessels, it is envisaged that dynamic tensional, resistive, and compressive forces exist in the parabronchus, forming a tensegrity (tension integrity) system that gives the lung rigidity while strengthening the air and blood capillaries.
Collapse
Affiliation(s)
- John N Maina
- Department of Zoology, University of Johannesburg, South Africa.
| | | | | |
Collapse
|
46
|
Abstract
We have previously reconstructed the entire coronary arterial tree of the porcine heart down to the first segment of capillaries. Here, we extend the vascular model through the capillary bed and the entire coronary venous system. The reconstruction was based on comprehensive morphometric data previously measured in the porcine heart. The reconstruction was formulated as a large-scale optimization process, subject to both global constraints relating to the location of the larger veins and to local constraints of measured morphological features. The venous network was partitioned into epicardial, transmural, and perfusion functional subnetworks. The epicardial portion was generated by a simulated annealing search for the optimal coverage of the area perfused by the arterial epicardial vessels. The epicardial subnetwork and coronary arterial capillary network served as boundary conditions for the reconstruction of the in-between transmural and perfusion networks, which were generated to optimize vascular homogeneity. Five sets of full coronary trees, which spanned the entire network down to the capillary level, were reconstructed. The total number of reconstructed venous segments was 17,148,946 ± 1,049,498 (n = 5), which spanned the coronary sinus (order -12) to the first segment of the venous capillary (order 0v). Combined with the reconstructed arterial network, the number of vessel segments for the entire coronary network added up to 27,307,376 ± 1,155,359 (n = 5). The reconstructed full coronary vascular network agreed with the gross anatomy of coronary networks in terms of structure, location of major vessels, and measured morphometric statistics of native coronary networks. This is the first full model of the entire coronary vasculature, which can serve as a foundation for realistic large-scale coronary flow analysis.
Collapse
Affiliation(s)
- Benjamin Kaimovitz
- Faculty of Biomedical Engineering, Israel Institute of Technology, Haifa, Israel
| | | | | |
Collapse
|
47
|
Blagonravov ML, Azova MM, Frolov VA. Chronobiology of Cardiac Ventricular Fibrillation Development in Experimental Acute Coronary Failure. Bull Exp Biol Med 2010; 149:559-61. [PMID: 21165386 DOI: 10.1007/s10517-010-0992-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- M L Blagonravov
- Department of General Pathology and Pathophysiology, Russian University of Peoples' Friendship, Moscow, Russia.
| | | | | |
Collapse
|
48
|
Mandroukas A, Metaxas T, Kesidis N, Christoulas K, Vamvakoudis E, Stefanidis P, Heller J, Ekblom B, Mandroukas K. Deltoid muscle fiber characteristics in adolescent and adult wrestlers. J Sports Med Phys Fitness 2010; 50:113-120. [PMID: 20585288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
AIM The aim of the present study was to examine the adaptation of myosin heavy chain (MHC) isoforms, capillary density and fiber cross sectional area (CSA) of deltoid muscle in adolescent and adult elite Greco-Roman wrestlers. METHODS Eighteen Greco-Roman wrestlers were divided into two groups: adolescents included 10 athletes (group A) between 14-18 years of age (15.4+/-1.3 yrs) and adults included 8 athletes (group B) between 20-27 years (23.5+/-2.6 yrs). Histochemical analyses were used to determine the muscle fiber type distribution and the muscle fiber cross sectional area. MHC isoform composition was determined with protein electrophoresis, while capillary density (capillary to fiber ratio and capillaries per mm2) analysis was performed with a-amylase Periodic and Schiff staining. RESULTS Adolescents demonstrated a significantly higher percentage of type I fibers (P<0.05) and type I fiber area (P<0.05) compared to the adults. The percentage of type IIa fiber area were significantly higher in adult wrestlers (P<0.05). MHC I isoforms was significantly higher in adolescents (P<0.05), whereas the MHC isoforms of IIa and IIx did not differ between groups. The capillary density (mm2) were significantly higher (P<0.05) in adolescents compared to adults. CONCLUSION Our findings suggest that the observed muscle fiber profile in the deltoid muscle of wrestlers may represent an adaptation based on the mechanical and biochemical demands of the long-term training. Such adaptations are linked to the specific characteristics of the training program, the level and the previous training experience of the wrestlers.
Collapse
Affiliation(s)
- A Mandroukas
- Faculty of Physical Education and Sports, Charles University, Prague, Czech Republic.
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kutscher HL, Chao P, Deshmukh M, Singh Y, Hu P, Joseph LB, Reimer DC, Stein S, Laskin DL, Sinko PJ. Threshold size for optimal passive pulmonary targeting and retention of rigid microparticles in rats. J Control Release 2010; 143:31-7. [PMID: 20043961 PMCID: PMC2840186 DOI: 10.1016/j.jconrel.2009.12.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 12/19/2009] [Indexed: 10/20/2022]
Abstract
The relationship between microparticle (MP) size and lung targeting efficiency, intra-lung distribution and retention time was systematically studied after intravenous administration of rigid fluorescent polystyrene MPs of various sizes (2, 3, 6 and 10 microm) to Sprague Dawley rats. Total fluorescence was assessed and it was found that 2 microm and 3 microm MPs readily passed through the lung to the liver and spleen while 10 microm MPs were completely entrapped in the lung for the one-week duration of the study. Approximately 84% of 6 microm MPs that were initially entrapped in the lung were cleared over the next 2 days and 15% were cleared over the remaining 5 days. A Caliper IVIS 100 small animal imaging system confirmed that 3 microm MPs were not retained in the lung but that 6 microm and 10 microm MPs were widely distributed throughout the lung. Moreover, histologic examination showed MP entrapment in capillaries but not arterioles. These studies suggest that for rigid MPs the optimal size range required to achieve transient but highly efficiently targeting to pulmonary capillaries after IV injection is >6 microm but <10 microm in rats and that systemic administration of optimally sized MPs may be an efficient alternative to currently used inhalation-based delivery to the lung.
Collapse
Affiliation(s)
- Hilliard L Kutscher
- Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Ghajar CM, Kachgal S, Kniazeva E, Mori H, Costes SV, George SC, Putnam AJ. Mesenchymal cells stimulate capillary morphogenesis via distinct proteolytic mechanisms. Exp Cell Res 2010; 316:813-25. [PMID: 20067788 DOI: 10.1016/j.yexcr.2010.01.013] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 12/14/2009] [Accepted: 01/05/2010] [Indexed: 12/17/2022]
Abstract
During angiogenesis, endothelial cells (ECs) degrade their surrounding extracellular matrix (ECM) to facilitate invasion. How interactions between ECs and other cells within their microenvironment facilitate this process is only partially understood. We have utilized a tractable 3D co-culture model to investigate the proteolytic mechanisms by which pre-committed or more highly committed mesenchymal cells stimulate capillary formation. On their own, ECs invade their surrounding matrix, but do not form capillaries. However, in the presence of either mesenchymal stem cells (MSCs) or fibroblasts, ECs form polarized, tubular structures that are intimately associated with mesenchymal cells. Further, ECs up-regulate gene expression of several extracellular proteases upon co-culture with either mesenchymal cell type. The administration of both broad spectrum and specific protease inhibitors demonstrated that MSC-stimulated capillary formation relied solely on membrane-type matrix metalloproteinases (MT-MMPs) while fibroblast-mediated sprouting proceeded independent of MMP inhibition unless the plasminogen activator/plasmin axis was inhibited in concert. While other studies have established a role for the ECM itself in dictating proteolysis and matrix degradation during capillary morphogenesis, the present study illustrates that heterotypic cellular interactions within the microenvironment can direct the proteolytic mechanisms required for capillary formation.
Collapse
Affiliation(s)
- Cyrus M Ghajar
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | | | | | | | | | | | | |
Collapse
|