1
|
Joshi K, Diaz A, O'Keeffe K, Schaffer JD, Chiarot PR, Huang P. Flow in temporally and spatially varying porous media: a model for transport of interstitial fluid in the brain. J Math Biol 2024; 88:69. [PMID: 38664246 DOI: 10.1007/s00285-024-02092-x] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 02/02/2024] [Accepted: 04/02/2024] [Indexed: 05/12/2024]
Abstract
Flow in a porous medium can be driven by the deformations of the boundaries of the porous domain. Such boundary deformations locally change the volume fraction accessible by the fluid, creating non-uniform porosity and permeability throughout the medium. In this work, we construct a deformation-driven porous medium transport model with spatially and temporally varying porosity and permeability that are dependent on the boundary deformations imposed on the medium. We use this model to study the transport of interstitial fluid along the basement membranes in the arterial walls of the brain. The basement membrane is modeled as a deforming annular porous channel with the compressible pore space filled with an incompressible, Newtonian fluid. The role of a forward propagating peristaltic heart pulse wave and a reverse smooth muscle contraction wave on the flow within the basement membranes is investigated. Our results identify combinations of wave amplitudes that can induce either forward or reverse transport along these transport pathways in the brain. The magnitude and direction of fluid transport predicted by our model can help in understanding the clearance of fluids and solutes along the Intramural Periarterial Drainage route and the pathology of cerebral amyloid angiopathy.
Collapse
Affiliation(s)
- Ketaki Joshi
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Adrian Diaz
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Katherine O'Keeffe
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - J David Schaffer
- Institute for Justice and Well-Being, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Paul R Chiarot
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Peter Huang
- Department of Mechanical Engineering, Watson College of Engineering and Applied Science, State University of New York at Binghamton, Binghamton, NY, 13902, USA.
| |
Collapse
|
2
|
Zhao S, Chen Z, Li T, Sun Q, Leng H, Huo B. Numerical simulations of fluid flow in trabecular-lacunar cavities under cyclic loading. Comput Biol Med 2023; 163:107144. [PMID: 37315384 DOI: 10.1016/j.compbiomed.2023.107144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 03/17/2023] [Revised: 05/23/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND Under external loading, the fluid shear stress (FSS) in the porous structures of bones, such as trabecular or lacunar-canalicular cavity, can influence the biological response of bone cells. However, few studies have considered both cavities. The present study investigated the characteristics of fluid flow at different scales in cancellous bone in rat femurs, as well as the effects of osteoporosis and loading frequency. METHODS Sprague Dawley rats (3 months old) were divided into normal and osteoporotic groups. A multiscale 3D fluid-solid coupling finite element model considering trabecular system and lacunar-canalicular system was established. Cyclic displacement loadings with frequencies of 1, 2, and 4 Hz were applied. FINDINGS Results showed that the wall FSS around the adhesion complexes of osteocyte on the canaliculi was higher than that on the osteocyte body. Under the same loading conditions, the wall FSS of the osteoporotic group was smaller than that of the normal group. The fluid velocity and FSS in trabecular pores exhibited a linear relationship with loading frequency. Similarly, the FSS around osteocytes also showed the loading frequency-dependent phenomenon. INTERPRETATION The high cadence in movement can effectively increase the FSS level on osteocytes for osteoporotic bone, i.e., expand the space within the bone with physiological load. This study might help in understanding the process of bone remodeling under cyclic loading and provide the fundamental data for the development of strategies for osteoporosis treatment.
Collapse
Affiliation(s)
- Sen Zhao
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Zebin Chen
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Taiyang Li
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Qing Sun
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Huijie Leng
- Department of Orthopaedics, Peking University Third Hospital, Beijing, 100191, PR China
| | - Bo Huo
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, PR China; Institute of Artificial Intelligence in Sports, Capital University of Physical Education and Sports, Beijing, 100091, PR China.
| |
Collapse
|
3
|
Abstract
Living things comprise a typical hierarchical and porous medium, and their most fundamental logical architectures are interstitial structures encapsulating parenchymal structures. The recent discovery of the efficient transport mechanisms of interstitial streams has provided a new understanding of these complex activities. The substance transport of interstitial streams follows mesoscopic fluid behavior dynamics, which is intimately associated with material transfer in nanoconfined spaces and a unique signal transmission. Accordingly, the evaluation of interstitial stream transport behavior at the mesoscopic scale is essential. In this review, recent advances in physical and chemical properties, the substance transport model, and the characterization methods of interstitial streams at the mesoscopic scale, as well as the relationships between interstitial streams and disease are summarized. Interstitial stream transport can be used as a basis to fully mine hierarchal behavior in images to expand imaging behavior into an omics field. By starting from the perspective of soft matter, a new understanding can be gained of health and disease and quantitative physical markers for research, clinical diagnosis, and treatment can be provided, as well as prognosis evaluation in complex diseases such as cancer and Alzheimer's disease. This will provide a foundation for the development of medicine of soft matter.
Collapse
Affiliation(s)
- Wen‐Tao Liu
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
| | - Yu‐Peng Cao
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| | - Xiao‐Han Zhou
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| | - Dong Han
- CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P. R. China
- School of Future TechnologyUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| |
Collapse
|
4
|
Rey JA, Ewing JR, Sarntinoranont M. A computational model of glioma reveals opposing, stiffness-sensitive effects of leaky vasculature and tumor growth on tissue mechanical stress and porosity. Biomech Model Mechanobiol 2021; 20:1981-2000. [PMID: 34363553 DOI: 10.1007/s10237-021-01488-8] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 06/29/2021] [Indexed: 11/29/2022]
Abstract
A biphasic computational model of a growing, vascularized glioma within brain tissue was developed to account for unique features of gliomas, including soft surrounding brain tissue, their low stiffness relative to brain tissue, and a lack of draining lymphatics. This model is the first to couple nonlinear tissue deformation with porosity and tissue hydraulic conductivity to study the mechanical interaction of leaky vasculature and solid growth in an embedded glioma. The present model showed that leaky vasculature and elevated interstitial fluid pressure produce tensile stress within the tumor in opposition to the compressive stress produced by tumor growth. This tensile effect was more pronounced in softer tissue and resulted in a compressive stress concentration at the tumor rim that increased when tumor was softer than host. Aside from generating solid stress, fluid pressure-driven tissue deformation decreased the effective stiffness of the tumor while growth increased it, potentially leading to elevated stiffness in the tumor rim. A novel prediction of reduced porosity at the tumor rim was corroborated by direct comparison with estimates from our in vivo imaging studies. Antiangiogenic and radiation therapy were simulated by varying vascular leakiness and tissue hydraulic conductivity. These led to greater solid compression and interstitial pressure in the tumor, respectively, the former of which may promote tumor infiltration of the host. Our findings suggest that vascular leakiness has an important influence on in vivo solid stress, stiffness, and porosity fields in gliomas given their unique mechanical microenvironment.
Collapse
Affiliation(s)
- Julian A Rey
- Department of Mechanical and Aerospace Engineering, University of Florida, PO BOX 116250, Gainesville, FL, 32611, USA
| | - James R Ewing
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Malisa Sarntinoranont
- Department of Mechanical and Aerospace Engineering, University of Florida, PO BOX 116250, Gainesville, FL, 32611, USA.
| |
Collapse
|
5
|
Gatti V, Gelbs MJ, Guerra RB, Gerber MB, Fritton SP. Interstitial fluid velocity is decreased around cortical bone vascular pores and depends on osteocyte position in a rat model of disuse osteoporosis. Biomech Model Mechanobiol 2021; 20:1135-1146. [PMID: 33666792 DOI: 10.1007/s10237-021-01438-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 07/21/2020] [Accepted: 02/15/2021] [Indexed: 10/22/2022]
Abstract
Muscle paralysis induced with botulinum toxin (Botox) injection increases vascular porosity and reduces osteocyte lacunar density in the tibial cortical bone of skeletally mature rats. These morphological changes potentially affect interstitial fluid flow in the lacunar-canalicular porosity, which is thought to play a role in osteocyte mechanotransduction. The aim of this study was to investigate the effects of disuse-induced morphological changes on interstitial fluid velocity around osteocytes in the bone cortex. Micro-CT images from a previous study that quantified the effects of Botox-induced muscle paralysis on bone microarchitecture in skeletally mature rats were used to create high-resolution, animal-specific finite element models that included the vascular pores and osteocyte lacunae within the tibial metaphysis of Botox-injected (BTX, n = 8) and saline-injected control (CTRL, n = 8) groups. To quantify fluid flow, lacunar and canalicular porosities were modeled as fluid-saturated poroelastic materials, and boundary conditions were applied to simulate physiological loading. This modeling approach allowed a detailed quantification of the fluid flow velocities around osteocytes in a relatively large volume of bone tissue. The analysis demonstrated that interstitial fluid velocity at the vascular pore surfaces was significantly lower in BTX compared to CTRL because of the decreased vascular canal separation. No significant differences in average fluid velocity were observed at the osteocyte lacunae and no correlation was found between the fluid velocity and the lacunar density, which was significantly lower in BTX. Instead, the lacunar fluid velocity was dependent on the osteocyte's specific position in the bone cortex and its proximity to a vascular pore.
Collapse
Affiliation(s)
- Vittorio Gatti
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Michelle J Gelbs
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Rodrigo B Guerra
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Michael B Gerber
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Susannah P Fritton
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
| |
Collapse
|
6
|
Yu H, Basu S, Hallow KM. Cardiac and renal function interactions in heart failure with reduced ejection fraction: A mathematical modeling analysis. PLoS Comput Biol 2020; 16:e1008074. [PMID: 32804929 PMCID: PMC7451992 DOI: 10.1371/journal.pcbi.1008074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 03/20/2020] [Revised: 08/27/2020] [Accepted: 06/18/2020] [Indexed: 01/10/2023] Open
Abstract
Congestive heart failure is characterized by suppressed cardiac output and arterial filling pressure, leading to renal retention of salt and water, contributing to further volume overload. Mathematical modeling provides a means to investigate the integrated function and dysfunction of heart and kidney in heart failure. This study updates our previously reported integrated model of cardiac and renal functions to account for the fluid exchange between the blood and interstitium across the capillary membrane, allowing the simulation of edema. A state of heart failure with reduced ejection fraction (HF-rEF) was then produced by altering cardiac parameters reflecting cardiac injury and cardiovascular disease, including heart contractility, myocyte hypertrophy, arterial stiffness, and systemic resistance. After matching baseline characteristics of the SOLVD clinical study, parameters governing rates of cardiac remodeling were calibrated to describe the progression of cardiac hemodynamic variables observed over one year in the placebo arm of the SOLVD clinical study. The model was then validated by reproducing improvements in cardiac function in the enalapril arm of SOLVD. The model was then applied to prospectively predict the response to the sodium-glucose co-transporter 2 (SGLT2) inhibitor dapagliflozin, which has been shown to reduce heart failure events in HF-rEF patients in the recent DAPAHF clinical trial by incompletely understood mechanisms. The simulations predict that dapagliflozin slows cardiac remodeling by reducing preload on the heart, and relieves congestion by clearing interstitial fluid without excessively reducing blood volume. This provides a quantitative mechanistic explanation for the observed benefits of SGLT2i in HF-rEF. The model also provides a tool for further investigation of heart failure drug therapies.
Collapse
Affiliation(s)
- Hongtao Yu
- School of Chemical, Materials, and Biomedical Engineering, University of Georgia, Athens, Georgia, United States of America
| | - Sanchita Basu
- School of Chemical, Materials, and Biomedical Engineering, University of Georgia, Athens, Georgia, United States of America
| | - K. Melissa Hallow
- School of Chemical, Materials, and Biomedical Engineering, University of Georgia, Athens, Georgia, United States of America
- Department of Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, United States of America
| |
Collapse
|
7
|
Youngblood RT, Brzostowski JT, Hafner BJ, Czerniecki JM, Allyn KJ, Foster RL, Sanders JE. Effectiveness of elevated vacuum and suction prosthetic suspension systems in managing daily residual limb fluid volume change in people with transtibial amputation. Prosthet Orthot Int 2020; 44:155-163. [PMID: 32186238 PMCID: PMC7443051 DOI: 10.1177/0309364620909044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 02/03/2023]
Abstract
BACKGROUND Previous studies investigating limb volume change with elevated vacuum have shown inconsistent results and have been limited by out-of-socket volume measurements and short, single-activity protocols. OBJECTIVES To evaluate the effectiveness of elevated vacuum for managing limb fluid volume compared to suction suspension with an in-socket measurement modality during many hours of activity. STUDY DESIGN Fixed-order crossover design with a standardized out-of-laboratory activity protocol. METHODS Transtibial electronic elevated vacuum users participated in two sessions. Elevated vacuum was used during the first session, and suction suspension in the second. Participants completed a 5.5-h protocol consisting of multiple intervals of activity. In-socket residual limb fluid volume was continuously measured using a custom portable bioimpedance analyzer. RESULTS A total of 12 individuals participated. Overall rate of fluid volume change was not significantly different, though the rate of posterior fluid volume change during Cycle 3 was significantly lower with elevated vacuum. Although individual results varied, 11 participants experienced lower overall rates of fluid volume loss in at least one limb region using elevated vacuum. CONCLUSION Elevated vacuum may be more effective as a volume management strategy after accumulation of activity. Individual variation suggests the potential to optimize the limb fluid volume benefits of elevated vacuum by reducing socket vacuum pressure for some users. CLINICAL RELEVANCE A better understanding of how elevated vacuum (EV) affects residual limb fluid volume will allow prosthetists to make more informed clinical decisions regarding accommodation strategies designed to improve daily socket fit.
Collapse
Affiliation(s)
| | | | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Joseph M Czerniecki
- VA Center for Limb Loss and Mobility, VA Puget Sound Health Care System, Seattle, WA, USA
| | - Katheryn J Allyn
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | | | - Joan E Sanders
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| |
Collapse
|
8
|
Myers JN, Bradford AJ, Hallas VS, Lawson LL, Pitcher TE, Dunham RA, Butts IAE. Channel catfish ovarian fluid differentially enhances blue catfish sperm performance. Theriogenology 2020; 149:62-71. [PMID: 32247214 DOI: 10.1016/j.theriogenology.2020.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 09/24/2019] [Revised: 02/24/2020] [Accepted: 03/12/2020] [Indexed: 12/12/2022]
Abstract
For externally fertilizing fishes, interactions between male and female gametes have been shown to have remarkable impacts on sperm performance. Ovarian fluid (OF) and its ability to alter the swimming behavior of fish sperm makes it a determining factor of fertility. With the expansion of channel catfish (Ictalurus punctatus) ♀ × blue catfish (Ictalurus furcatus) ♂ hybrid aquaculture, it is essential to understand the impacts during fertilization and the magnitude such gametic interactions have on sperm performance and subsequent male fertility potential. This study was conducted to address the following: 1) activate blue catfish sperm with/without channel catfish OF to determine impacts on sperm performance and 2) assess if sperm behave differently when activated in the OF from individual females. Sperm (n = 4 males) were activated without OF (control) and with diluted OF from unique females (n = 6), creating 24 experimental crosses. Sperm motility (%), velocity (VCL), and longevity were analyzed using computer assisted sperm analyses software. With OF incorporated in the activation media, sperm velocity was significantly higher than the control at 10, 20, and 30 s post-activation. OF did not have an impact on motility for any females at 10 s and 20 s post-activation but became significantly higher than the control at 30 s. In all cases, OF treatments greatly increased longevity. Male × female interactions were highly significant, such that motility, velocity, and longevity were dependent on specific male-female pairs. This information shows that OF should be incorporated in aquatic media to simulate natural spawning conditions and accurately assess the fluid mechanics of sperm propulsion for each male. Additionally, there are mechanisms that drive gamete interactions that need to be explored further, which may improve selection of male-female pairs for in-vitro fertilization. On a broad scale, our results also help to shed light on the complexities of fertilization and fish reproduction overall, which may have implications for recruitment variability and recovery strategies of threatened and/or endangered freshwater species.
Collapse
Affiliation(s)
- J N Myers
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - A J Bradford
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - V S Hallas
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - L L Lawson
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - T E Pitcher
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON N9B 3P4, Canada; Department of Biological Sciences, University of Windsor, Windsor, ON N9B 3P4, Canada.
| | - R A Dunham
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - I A E Butts
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| |
Collapse
|
9
|
Offeddu GS, Possenti L, Loessberg-Zahl JT, Zunino P, Roberts J, Han X, Hickman D, Knutson CG, Kamm RD. Application of Transmural Flow Across In Vitro Microvasculature Enables Direct Sampling of Interstitial Therapeutic Molecule Distribution. Small 2019; 15:e1902393. [PMID: 31497931 DOI: 10.1002/smll.201902393] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [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: 05/11/2019] [Revised: 08/13/2019] [Indexed: 06/10/2023]
Abstract
In vitro prediction of physiologically relevant transport of therapeutic molecules across the microcirculation represents an intriguing opportunity to predict efficacy in human populations. On-chip microvascular networks (MVNs) show physiologically relevant values of molecular permeability, yet like most systems, they lack an important contribution to transport: the ever-present fluid convection through the endothelium. Quantification of transport through the MVNs by current methods also requires confocal imaging and advanced analytical techniques, which can be a bottleneck in industry and academic laboratories. Here, it is shown that by recapitulating physiological transmural flow across the MVNs, the concentration of small and large molecule therapeutics can be directly sampled in the interstitial fluid and analyzed using standard analytical techniques. The magnitudes of transport measured in MVNs reveal trends with molecular size and type (protein versus nonprotein) that are expected in vivo, supporting the use of the MVNs platform as an in vitro tool to predict distribution of therapeutics in vivo.
Collapse
Affiliation(s)
- Giovanni S Offeddu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Luca Possenti
- LaBS, Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milan, 20133, Italy
| | | | - Paolo Zunino
- MOX, Department of Mathematics, Politecnico di Milano, Milan, 20133, Italy
| | - John Roberts
- Amgen Discovery Research, Amgen Inc., 360 Binney Street, Cambridge, MA, 02141, USA
| | - Xiaogang Han
- Amgen Discovery Research, Amgen Inc., 360 Binney Street, Cambridge, MA, 02141, USA
| | - Dean Hickman
- Amgen Discovery Research, Amgen Inc., 360 Binney Street, Cambridge, MA, 02141, USA
| | - Charles G Knutson
- Amgen Discovery Research, Amgen Inc., 360 Binney Street, Cambridge, MA, 02141, USA
| | - Roger D Kamm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| |
Collapse
|
10
|
Connor BW, Carvalho H. Using Dramatization to Teach Starling Forces in the Microcirculation to First-Year Medical Students. MedEdPORTAL 2019; 15:10842. [PMID: 31911933 PMCID: PMC6944257 DOI: 10.15766/mep_2374-8265.10842] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/09/2019] [Indexed: 06/10/2023]
Abstract
INTRODUCTION The clinical importance, prevalence, and multiple etiologies of tissue edema make it a critical part of medical education. Given the multiple physiological parameters that must be simultaneously considered to determine fluid movement, it is important that a deeper understanding of the microcirculation and fluid shifts is achieved in preclinical education. METHODS We describe an innovative teaching methodology using dramatization to interactively teach Starling forces to first-year medical students. Prior to the dramatization, students were given an introduction to Starling forces. They also completed a brief knowledge quiz on the topic before and after the activity. The classroom walls were marked with signs representing the intravascular space, extravascular or interstitium, and lymphatics compartments. Students were invited to act out or mimic the fluid shifts within capillaries as the values for hydrostatic and colloid osmotic pressures for the intravascular and interstitial spaces were presented. The goal was for each student to decide which compartment he/she would move to as fluid according to Starling force values and/or clinical scenarios. RESULTS A significant improvement between pre- and postactivity quiz performance (45.4% ± 25.1% and 77.5% ± 14.1%, respectively) was observed (n = 26, p < .001, t test). In a postactivity survey, 85% of students reported the activity to be an effective way of learning. DISCUSSION Our data indicate that this dramatization approach is effective in complementing passive learning in traditional lectures. Furthermore, this type of dynamic activity brings joy to the classroom and breaks the monotony of lecturing.
Collapse
Affiliation(s)
| | - Helena Carvalho
- Associate Professor, Department of Basic Science Education, Virginia Tech Carilion School of Medicine
| |
Collapse
|
11
|
Arokiasamy S, King R, Boulaghrasse H, Poston RN, Nourshargh S, Wang W, Voisin MB. Heparanase-Dependent Remodeling of Initial Lymphatic Glycocalyx Regulates Tissue-Fluid Drainage During Acute Inflammation in vivo. Front Immunol 2019; 10:2316. [PMID: 31636638 PMCID: PMC6787176 DOI: 10.3389/fimmu.2019.02316] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [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: 05/09/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
The glycocalyx is a dense layer of carbohydrate chains involved in numerous and fundamental biological processes, such as cellular and tissue homeostasis, inflammation and disease development. Composed of membrane-bound glycoproteins, sulfated proteoglycans and glycosaminoglycan side-chains, this structure is particularly essential for blood vascular barrier functions and leukocyte diapedesis. Interestingly, whilst the glycocalyx of blood vascular endothelium has been extensively studied, little is known about the composition and function of this glycan layer present on tissue-associated lymphatic vessels (LVs). Here, we applied confocal microscopy to characterize the composition of endothelial glycocalyx of initial lymphatic capillaries in murine cremaster muscles during homeostatic and inflamed conditions using an anti-heparan sulfate (HS) antibody and a panel of lectins recognizing different glycan moieties of the glycocalyx. Our data show the presence of HS, α-D-galactosyl moieties, α2,3-linked sialic acids and, to a lesser extent, N-Acetylglucosamine moieties. A similar expression profile was also observed for LVs of mouse and human skins. Interestingly, inflammation of mouse cremaster tissues or ear skin as induced by TNF-stimulation induced a rapid (within 16 h) remodeling of the LV glycocalyx, as observed by reduced expression of HS and galactosyl moieties, whilst levels of α2,3-linked sialic acids remains unchanged. Furthermore, whilst this response was associated with neutrophil recruitment from the blood circulation and their migration into tissue-associated LVs, specific neutrophil depletion did not impact LV glycocalyx remodeling. Mechanistically, treatment with a non-anticoagulant heparanase inhibitor suppressed LV HS degradation without impacting neutrophil migration into LVs. Interestingly however, inhibition of glycocalyx degradation reduced the capacity of initial LVs to drain interstitial fluid during acute inflammation. Collectively, our data suggest that rapid remodeling of endothelial glycocalyx of tissue-associated LVs supports drainage of fluid and macromolecules but has no role in regulating neutrophil trafficking out of inflamed tissues via initial LVs.
Collapse
Affiliation(s)
- Samantha Arokiasamy
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
- School of Engineering and Materials Science, Institute of Bioengineering, Queen Mary University of London, London, United Kingdom
| | - Ross King
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Hidayah Boulaghrasse
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Robin N. Poston
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Sussan Nourshargh
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Wen Wang
- School of Engineering and Materials Science, Institute of Bioengineering, Queen Mary University of London, London, United Kingdom
| | - Mathieu-Benoit Voisin
- Barts and the London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| |
Collapse
|
12
|
Gulisano W, Melone M, Ripoli C, Tropea MR, Li Puma DD, Giunta S, Cocco S, Marcotulli D, Origlia N, Palmeri A, Arancio O, Conti F, Grassi C, Puzzo D. Neuromodulatory Action of Picomolar Extracellular Aβ42 Oligomers on Presynaptic and Postsynaptic Mechanisms Underlying Synaptic Function and Memory. J Neurosci 2019; 39:5986-6000. [PMID: 31127002 PMCID: PMC6650983 DOI: 10.1523/jneurosci.0163-19.2019] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 04/09/2019] [Accepted: 04/28/2019] [Indexed: 01/01/2023] Open
Abstract
Failure of anti-amyloid-β peptide (Aβ) therapies against Alzheimer's disease (AD), a neurodegenerative disorder characterized by high amounts of the peptide in the brain, raised the question of the physiological role of Aβ released at low concentrations in the healthy brain. To address this question, we studied the presynaptic and postsynaptic mechanisms underlying the neuromodulatory action of picomolar amounts of oligomeric Aβ42 (oAβ42) on synaptic glutamatergic function in male and female mice. We found that 200 pm oAβ42 induces an increase of frequency of miniature EPSCs and a decrease of paired pulse facilitation, associated with an increase in docked vesicle number, indicating that it augments neurotransmitter release at presynaptic level. oAβ42 also produced postsynaptic changes as shown by an increased length of postsynaptic density, accompanied by an increased expression of plasticity-related proteins such as cAMP-responsive element binding protein phosphorylated at Ser133, calcium-calmodulin-dependent kinase II phosphorylated at Thr286, and brain-derived neurotrophic factor, suggesting a role for Aβ in synaptic tagging. These changes resulted in the conversion of early into late long-term potentiation through the nitric oxide/cGMP/protein kinase G intracellular cascade consistent with a cGMP-dependent switch from short- to long-term memory observed in vivo after intrahippocampal administration of picomolar amounts of oAβ42 These effects were present upon extracellular but not intracellular application of the peptide and involved α7 nicotinic acetylcholine receptors. These observations clarified the physiological role of oAβ42 in synaptic function and memory formation providing solid fundamentals for investigating the pathological effects of high Aβ levels in the AD brains.SIGNIFICANCE STATEMENT High levels of oligomeric amyloid-β42 (oAβ42) induce synaptic dysfunction leading to memory impairment in Alzheimer's disease (AD). However, at picomolar concentrations, the peptide is needed to ensure long-term potentiation (LTP) and memory. Here, we show that extracellular 200 pm oAβ42 concentrations increase neurotransmitter release, number of docked vesicles, postsynaptic density length, and expression of plasticity-related proteins leading to the conversion of early LTP into late LTP and of short-term memory into long-term memory. These effects require α7 nicotinic acetylcholine receptors and are mediated through the nitric oxide/cGMP/protein kinase G pathway. The knowledge of Aβ function in the healthy brain might be useful to understand the causes leading to its increase and detrimental effect in AD.
Collapse
Affiliation(s)
- Walter Gulisano
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Marcello Melone
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
- Center for Neurobiology of Aging, IRCCS Istituto Nazionale Ricovero e Cura Anziani (INRCA), Ancona 60020, Italy
| | - Cristian Ripoli
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Maria Rosaria Tropea
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Domenica D Li Puma
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Salvatore Giunta
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Sara Cocco
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Daniele Marcotulli
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
| | - Nicola Origlia
- Neuroscience Institute, Italian National Research Council, Pisa 56100, Italy
| | - Agostino Palmeri
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York 10032
| | - Fiorenzo Conti
- Section of Neuroscience and Cell Biology, Department Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona 60020, Italy
- Center for Neurobiology of Aging, IRCCS Istituto Nazionale Ricovero e Cura Anziani (INRCA), Ancona 60020, Italy
- Foundation for Molecular Medicine, Università Politecnica delle Marche, Ancona 60020, Italy, and
| | - Claudio Grassi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome 00168, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Daniela Puzzo
- Department Biomedical and Biotechnological Sciences, University of Catania, Catania 95123, Italy,
- Oasi Research Institute-IRCCS, Troina, 94018, Italy
| |
Collapse
|
13
|
Sweeney PW, d’Esposito A, Walker-Samuel S, Shipley RJ. Modelling the transport of fluid through heterogeneous, whole tumours in silico. PLoS Comput Biol 2019; 15:e1006751. [PMID: 31226169 PMCID: PMC6588205 DOI: 10.1371/journal.pcbi.1006751] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 12/24/2018] [Accepted: 05/12/2019] [Indexed: 11/18/2022] Open
Abstract
Cancers exhibit spatially heterogeneous, unique vascular architectures across individual samples, cell-lines and patients. This inherently disorganised collection of leaky blood vessels contribute significantly to suboptimal treatment efficacy. Preclinical tools are urgently required which incorporate the inherent variability and heterogeneity of tumours to optimise and engineer anti-cancer therapies. In this study, we present a novel computational framework which incorporates whole, realistic tumours extracted ex vivo to efficiently simulate vascular blood flow and interstitial fluid transport in silico for validation against in vivo biomedical imaging. Our model couples Poiseuille and Darcy descriptions of vascular and interstitial flow, respectively, and incorporates spatially heterogeneous blood vessel lumen and interstitial permeabilities to generate accurate predictions of tumour fluid dynamics. Our platform enables highly-controlled experiments to be performed which provide insight into how tumour vascular heterogeneity contributes to tumour fluid transport. We detail the application of our framework to an orthotopic murine glioma (GL261) and a human colorectal carcinoma (LS147T), and perform sensitivity analysis to gain an understanding of the key biological mechanisms which determine tumour fluid transport. Finally we mimic vascular normalization by modifying parameters, such as vascular and interstitial permeabilities, and show that incorporating realistic vasculatures is key to modelling the contrasting fluid dynamic response between tumour samples. Contrary to literature, we show that reducing tumour interstitial fluid pressure is not essential to increase interstitial perfusion and that therapies should seek to develop an interstitial fluid pressure gradient. We also hypothesise that stabilising vessel diameters and permeabilities are not key responses following vascular normalization and that therapy may alter interstitial hydraulic conductivity. Consequently, we suggest that normalizing the interstitial microenvironment may provide a more effective means to increase interstitial perfusion within tumours. The structure of tumours varies widely, with dense and chaotically-formed networks of blood vessels that differ between each individual tumour and even between different regions of the same tumour. This atypical environment can inhibit the delivery of anti-cancer therapies. Computational tools are urgently required which facilitate a deeper understanding of the relationship between blood vessel architectures and therapeutic response. We have developed a computational framework which integrates the complex tumour vascular architecture to predict fluid transport across all lengths scales in whole tumours. We apply our model to two tumour cell-lines and show that differences in their inherent vascular structures influence flow through cancerous tissue. We also use our platform to predict the fluid dynamic response following vascular normalization therapy in realistic, static tumour networks and show that the response is dependent on tumour vascular architecture. We hypothesise that therapy may alter the permeability of interstitial tissue to fluid transport and show that lowering interstitial fluid pressure is not a necessary therapeutic outcome to increase tumour perfusion.
Collapse
Affiliation(s)
- Paul W. Sweeney
- Mechanical Engineering, University College London, London, United Kingdom
| | - Angela d’Esposito
- Centre for Advanced Biomedical Engineering, University College London, London, United Kingdom
| | - Simon Walker-Samuel
- Centre for Advanced Biomedical Engineering, University College London, London, United Kingdom
| | - Rebecca J. Shipley
- Mechanical Engineering, University College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
14
|
Głąbska D, Cackowska K, Guzek D. Comparison of the Body Composition of Caucasian Young Normal Body Mass Women, Measured in the Follicular Phase, Depending on the Carbohydrate Diet Level. ACTA ACUST UNITED AC 2018; 54:medicina54060104. [PMID: 30563184 PMCID: PMC6306892 DOI: 10.3390/medicina54060104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 09/28/2018] [Revised: 11/14/2018] [Accepted: 12/02/2018] [Indexed: 12/28/2022]
Abstract
Background and objectives: Some publications indicate the possibility of the influence of meal nutritional value on results of bioelectrical impedance, and of the relation between the long-term carbohydrate intake and body composition. The aim of the presented study was to evaluate the influence of long-term intake of carbohydrates on body composition results assessed using the bioelectrical impedance of Caucasian young women with normal body mass, who were in the follicular phase of their menstrual cycle. Materials and Methods: Body composition was assessed in 100 women (18–30 years), according to strict rules, to minimize the influence of disturbing factors and by using two types of bioelectrical impedance device of the same operator to eliminate the influence of measurement (BIA 101/SC and BIA 101/ASE by Akern Srl, Firenze, Italy with the Bodygram 1.31 software and its equations by Akern Srl, Firenze, Italy). The analysis included validation of reproducibility of body composition assessment (fat, fat-free, body cell and muscle mass, water, extracellular water, and intracellular water content), and comparison of body composition for groups characterized by carbohydrate content <50% (n = 55) and >50% of the energy value of the diet (n = 45). Results: Analysis conducted using Bland–Altman method, analysis of correlation, analysis of quartile distribution, and weighted κ statistic revealed a positively validated reproducibility, but extracellular water associations were the weakest. Depending on the device, participants characterized by higher carbohydrate intake had significantly higher intracellular water content (p = 0.0448), or close to significantly higher (p = 0.0851) than those characterized by lower carbohydrate intake, whose extracellular water content was close to significantly lower (p = 0.0638) or did not differ. Conclusions: The long-term, moderately reduced, carbohydrate intake may cause the shift of intracellular water to the extracellular space and, as a result, influence the body composition results.
Collapse
Affiliation(s)
- Dominika Głąbska
- Department of Dietetics, Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences (WULS-SGGW), 159c Nowoursynowska Str., 02-776 Warsaw, Poland.
| | - Karolina Cackowska
- Department of Dietetics, Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences (WULS-SGGW), 159c Nowoursynowska Str., 02-776 Warsaw, Poland.
| | - Dominika Guzek
- Department of Organization and Consumption Economics, Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences (WULS-SGGW), 159c Nowoursynowska Str., 02-776 Warsaw, Poland.
| |
Collapse
|
15
|
Raizman R, MacNeil M, Rappl L. Utility of a sensor-based technology to assist in the prevention of pressure ulcers: A clinical comparison. Int Wound J 2018; 15:1033-1044. [PMID: 30160024 PMCID: PMC7949808 DOI: 10.1111/iwj.12974] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [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: 03/16/2018] [Revised: 07/05/2018] [Accepted: 07/10/2018] [Indexed: 02/03/2023] Open
Abstract
Detection of subcutaneous tissue damage before it is visible can trigger early intervention and decrease hospital-acquired pressure ulcer (HAPU) rates. The objective of this two-phase study was to evaluate the clinical utility of the Sub-Epidermal Moisture (SEM) Scanner (Bruin Biometrics (BBI), LLC), a hand-held device that assesses increases in interstitial fluid or subepidermal moisture, indicating early tissue damage. Phase 1: Patients were provided standard-of-care risk assessment and interventions and were scanned with the SEM Scanner, but the resulting SEM scores were not used to determine interventions. This gave a baseline pressure ulcer incidence rate. Phase 2: This phase is the same as Phase 1 except the resulting SEM scores were used in conjunction with risk assessment scores to determine appropriate interventions and care planning. In Phase 1, 12 of the 89 subjects or 13.5% developed visible pressure ulcers-4 Stage I's, 6 Stage II's, 1 Stage III, and 1 deep tissue injury. In Phase 2, 2 of the 195 subjects or 1.0% developed visible pressure ulcers-1 Stage I and 1 Stage II. Patients in Phase 2 were more incontinent, less mobile, and had longer lengths of stay than those in Phase 1. Use of the Scanner resulted in a 93% decrease in HAPU. No deep injuries developed in Phase 2.
Collapse
Affiliation(s)
- Rose Raizman
- Department of Professional PracticeScarborough Health NetworkCanada
| | - Minette MacNeil
- Department of Professional Practice, Allied Health & StaffingScarborough Health NetworkCanada
| | - Laurie Rappl
- Rappl and AssociatesLLCSimpsonvilleSouth Carolina
| |
Collapse
|
16
|
Sanders JE, Youngblood RT, Hafner BJ, Ciol MA, Allyn KJ, Gardner D, Cagle JC, Redd CB, Dietrich CR. Residual limb fluid volume change and volume accommodation: Relationships to activity and self-report outcomes in people with trans-tibial amputation. Prosthet Orthot Int 2018; 42:415-427. [PMID: 29402170 PMCID: PMC7447528 DOI: 10.1177/0309364617752983] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 02/03/2023]
Abstract
BACKGROUND Fluctuations in limb volume degrade prosthesis fit and require users to accommodate changes using management strategies, such as donning and doffing prosthetic socks. OBJECTIVES To examine how activities and self-report outcomes relate to daily changes in residual limb fluid volume and volume accommodation. STUDY DESIGN Standardized, two-part laboratory protocol with an interim observational period. METHODS Participants were classified as "accommodators" or "non-accommodators," based on self-report prosthetic sock use. Participants' residual limb fluid volume change was measured using a custom bioimpedance analyzer and a standardized in-laboratory activity protocol. Self-report health outcomes were assessed with the Socket Comfort Score and Prosthesis Evaluation Questionnaire. Activity was monitored while participants left the laboratory for at least 3 h. They then returned to repeat the bioimpedance test protocol. RESULTS Twenty-nine people were enrolled. Morning-to-afternoon percent limb fluid volume change per hour was not strongly correlated to percent time weight-bearing or to self-report outcomes. As a group, non-accommodators ( n = 15) spent more time with their prosthesis doffed and reported better outcomes than accommodators. CONCLUSION Factors other than time weight-bearing may contribute to morning-to-afternoon limb fluid volume changes and reported satisfaction with the prosthesis among trans-tibial prosthesis users. Temporary doffing may be a more effective and satisfying accommodation method than sock addition. Clinical relevance Practitioners should be mindful that daily limb fluid volume change and prosthesis satisfaction are not dictated exclusively by activity. Temporarily doffing the prosthesis may slow daily limb fluid volume loss and should be investigated as an alternative strategy to sock addition.
Collapse
|
17
|
Wang R, Liu X, Schoepf UJ, van Assen M, Alimohamed I, Griffith LP, Luo T, Sun Z, Fan Z, Xu L. Extracellular volume quantitation using dual-energy CT in patients with heart failure: Comparison with 3T cardiac MR. Int J Cardiol 2018; 268:236-240. [PMID: 29804697 DOI: 10.1016/j.ijcard.2018.05.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 01/23/2018] [Revised: 05/03/2018] [Accepted: 05/09/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUNDS Cardiac magnetic resonance (CMR) T1 mapping and the extracellular volume (ECV) have been developed to quantitative analysis of diffusely abnormal myocardial fibrosis (MF). However, dual-energy CT (DECT) has a potential for calculation of ECV. The aim of this study is to evaluate the feasibility and accuracy of DECT technique in determining the ECV in patients with heart failure, with 3T CMR as the reference. METHODS Thirty-five patients with various reasons of heart failure were enrolled in this study. Both DECT and CMR exams were completed within 24 h. ECVs were calculated, and the relationship between DECT-ECV, CMR-ECV, and other heart function parameters, including left ventricular end systolic and diastolic volume, cardiac output and ejection fraction (LVESV, LVEDV, CO, LVEF), Brain natriuretic peptide (BNP) was determined. All participants gave informed consent, and the study was approved by the institutional review board. RESULTS The median ECVs on DECT and CMR were 33% (95%CI: 32%-36%) and 30% (95%CI: 30% - 32%), respectively. A good correlation between myocardial ECV at DECT and that at CMR (r = 0.945, P < 0.001) was observed. Bland-Altman analysis between DECT and CMR showed a small bias (2.6%), with 95% limits of agreement of -0.4% and 5.6%. Interobserver agreement for ECV at DECT was excellent (ICC = 0.907). Both ECVs, for DECT and CMR, were inversely associated with LVEF and CO. CONCLUSION DECT-based ECV could be an alternative non-invasive imaging tool for myocardial tissue characterization. However, overestimation of the extent of diffuse MF is observed with use of DECT.
Collapse
Affiliation(s)
- Rui Wang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China
| | - Xinmin Liu
- Wards 40 of Cardiology Department, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University or South Carolina, Charleston, SC, USA; Division of Cardiology, Department of Internal Medicine, Medical University or South Carolina, Charleston, SC, USA
| | - Marly van Assen
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University or South Carolina, Charleston, SC, USA; Center for Medical Imaging North-East Netherlands (CMI-NEN), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Imtiaz Alimohamed
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University or South Carolina, Charleston, SC, USA
| | - L Parkwood Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University or South Carolina, Charleston, SC, USA
| | - Taiyang Luo
- Wards 40 of Cardiology Department, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China
| | - Zhonghua Sun
- Department of Medical Radiation Sciences, Curtin University, Perth, WA 6845, Australia
| | - Zhanming Fan
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China
| | - Lei Xu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China.
| |
Collapse
|
18
|
Walker-Samuel S, Roberts TA, Ramasawmy R, Burrell JS, Johnson SP, Siow BM, Richardson S, Gonçalves MR, Pendse D, Robinson SP, Pedley RB, Lythgoe MF. Investigating Low-Velocity Fluid Flow in Tumors with Convection-MRI. Cancer Res 2018; 78:1859-1872. [PMID: 29317434 PMCID: PMC6298581 DOI: 10.1158/0008-5472.can-17-1546] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [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: 05/26/2017] [Revised: 08/18/2017] [Accepted: 01/05/2018] [Indexed: 02/06/2023]
Abstract
Several distinct fluid flow phenomena occur in solid tumors, including intravascular blood flow and interstitial convection. Interstitial fluid pressure is often raised in solid tumors, which can limit drug delivery. To probe low-velocity flow in tumors resulting from raised interstitial fluid pressure, we developed a novel MRI technique named convection-MRI, which uses a phase-contrast acquisition with a dual-inversion vascular nulling preparation to separate intra- and extravascular flow. Here, we report the results of experiments in flow phantoms, numerical simulations, and tumor xenograft models to investigate the technical feasibility of convection-MRI. We observed a significant correlation between estimates of effective fluid pressure from convection-MRI with gold-standard, invasive measurements of interstitial fluid pressure in mouse models of human colorectal carcinoma. Our results show how convection-MRI can provide insights into the growth and responsiveness to vascular-targeting therapy in colorectal cancers.Significance: A noninvasive method for measuring low-velocity fluid flow caused by raised fluid pressure can be used to assess changes caused by therapy. Cancer Res; 78(7); 1859-72. ©2018 AACR.
Collapse
Affiliation(s)
- Simon Walker-Samuel
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK.
| | - Thomas A Roberts
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| | - Rajiv Ramasawmy
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| | - Jake S Burrell
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, Surrey, UK
| | | | - Bernard M Siow
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| | - Simon Richardson
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| | - Miguel R Gonçalves
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| | | | - Simon P Robinson
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, Surrey, UK
| | | | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, UK
| |
Collapse
|
19
|
Wang LH, Wang ZL, Chen WY, Chen MJ, Xu GY. [The glymphatic system: concept, function and research progresses]. Sheng Li Xue Bao 2018; 70:52-60. [PMID: 29492515] [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: 06/08/2023]
Abstract
The glymphatic system is a cerebrospinal fluid-interstitial fluid exchange system dependent on the water channel aquaporin-4 polarized on astrocyte endfeet, which is proposed to account for the clearance of abnormal proteins (e.g. β-amyloid) and metabolites (e.g. lactate) from the brain. Accumulating studies have revealed that glymphatic activity during sleep and general anesthesia is dramatically enhanced, while its function is significantly damaged during aging, traumatic brain injury, Alzheimer's disease, stroke, and diabetes. The glymphatic hypothesis is a breakthrough in the field of neuroscience recently, which would considerably enhance our comprehension on the cerebrospinal fluid circulation and its role in the maintenance of brain homeostasis. In this review, we briefly introduced the conceptualization of glymphatic system, summarized the recent progresses, and prospected its future investigation and potential clinical application.
Collapse
Affiliation(s)
- Lin-Hui Wang
- Department of Physiology and Neurobiology, Medical College, Soochow University, Suzhou 215123, China
- Institute of Neuroscience, Soochow University, Suzhou 215123, China.
| | - Zi-Lan Wang
- Department of Physiology and Neurobiology, Medical College, Soochow University, Suzhou 215123, China
| | - Wen-Yue Chen
- Department of Physiology and Neurobiology, Medical College, Soochow University, Suzhou 215123, China
| | - Ming-Jia Chen
- Department of Physiology and Neurobiology, Medical College, Soochow University, Suzhou 215123, China
| | - Guang-Yin Xu
- Institute of Neuroscience, Soochow University, Suzhou 215123, China.
| |
Collapse
|
20
|
Carden MA, Fay ME, Lu X, Mannino RG, Sakurai Y, Ciciliano JC, Hansen CE, Chonat S, Joiner CH, Wood DK, Lam WA. Extracellular fluid tonicity impacts sickle red blood cell deformability and adhesion. Blood 2017; 130:2654-2663. [PMID: 28978568 PMCID: PMC5731085 DOI: 10.1182/blood-2017-04-780635] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [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: 04/23/2017] [Accepted: 09/24/2017] [Indexed: 01/04/2023] Open
Abstract
Abnormal sickle red blood cell (sRBC) biomechanics, including pathological deformability and adhesion, correlate with clinical severity in sickle cell disease (SCD). Clinical intravenous fluids (IVFs) of various tonicities are often used during treatment of vaso-occlusive pain episodes (VOE), the major cause of morbidity in SCD. However, evidence-based guidelines are lacking, and there is no consensus regarding which IVFs to use during VOE. Further, it is unknown how altering extracellular fluid tonicity with IVFs affects sRBC biomechanics in the microcirculation, where vaso-occlusion takes place. Here, we report how altering extracellular fluid tonicity with admixtures of clinical IVFs affects sRBC biomechanical properties by leveraging novel in vitro microfluidic models of the microcirculation, including 1 capable of deoxygenating the sRBC environment to monitor changes in microchannel occlusion risk and an "endothelialized" microvascular model that measures alterations in sRBC/endothelium adhesion under postcapillary venular conditions. Admixtures with higher tonicities (sodium = 141 mEq/L) affected sRBC biomechanics by decreasing sRBC deformability, increasing sRBC occlusion under normoxic and hypoxic conditions, and increasing sRBC adhesion in our microfluidic human microvasculature models. Admixtures with excessive hypotonicity (sodium = 103 mEq/L), in contrast, decreased sRBC adhesion, but overswelling prolonged sRBC transit times in capillary-sized microchannels. Admixtures with intermediate tonicities (sodium = 111-122 mEq/L) resulted in optimal changes in sRBC biomechanics, thereby reducing the risk for vaso-occlusion in our models. These results have significant translational implications for patients with SCD and warrant a large-scale prospective clinical study addressing optimal IVF management during VOE in SCD.
Collapse
Affiliation(s)
- Marcus A Carden
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA
| | - Meredith E Fay
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA
| | - Xinran Lu
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN
| | - Robert G Mannino
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA
| | - Yumiko Sakurai
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA
| | - Jordan C Ciciliano
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, and
| | - Caroline E Hansen
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA
| | - Satheesh Chonat
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
| | - Clinton H Joiner
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
| | - David K Wood
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN
| | - Wilbur A Lam
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Aflac Cancer & Blood Disorders Center, Emory University School of Medicine, Atlanta, GA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA
| |
Collapse
|
21
|
Sakuma T, Yamashita K, Miyakoshi T, Shimodaira M, Yokota N, Sato Y, Hirabayashi K, Koike H, Yamauchi K, Shimbo T, Aizawa T. Postchallenge hyperglycemia in subjects with low body weight: implication for small glucose volume. Am J Physiol Endocrinol Metab 2017; 313:E748-E756. [PMID: 28874359 DOI: 10.1152/ajpendo.00203.2017] [Citation(s) in RCA: 2] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/31/2017] [Accepted: 08/24/2017] [Indexed: 11/22/2022]
Abstract
A hypothesis that postchallenge hyperglycemia in subjects with low body weight (BW) may be due, in part, to small glucose volume (GV) was tested. We studied 11,411 nondiabetic subjects with a mean BW of 63.3 kg; 5,282 of them were followed for a mean of 5.3 yr. In another group of 1,537 nondiabetic subjects, insulin sensitivity, secretion, and a product of the two (index of whole body insulin action) were determined. Corrected 2 h-plasma glucose (2hPGcorr) during a 75-g oral glucose tolerance test in subjects with BW ≤ 59 kg was calculated as 2hPGcorr = δPG2h · ECW/[16.1 (males) or 15.3 (females)] + fasting PG (FPG), where δPG2h is plasma glucose increment in 2 h; ECW is extracellular water (surrogate of GV); FPG is fasting plasma glucose; and 16.1 and 15.3 are ECW of men and women, respectively, with BW = 59 kg. Multivariate analyses for BW with adjustment for age, sex, and percent body fat were undertaken. BW was, across its entire range, positively correlated with FPG (P < 0.01). Whereas BW was correlated with 2hPG and δPG in a skewed J-shape, with inflections at around 60 kg (P for nonlinearity < 0.01 for each). Nonetheless, in those with BW ≤ 59 kg, insulin sensitivity, secretion, and action were unattenuated, and incident diabetes was less compared with heavier counterparts. BW was linearly correlated with 2hPGcorr, i.e., the J-shape correlation was mitigated by the correction. In conclusion, postchallenge hyperglycemia in low BW subjects is in part due to small GV rather than impaired glucose metabolism.
Collapse
Affiliation(s)
- Takahiro Sakuma
- Department of Medicine, Ina Central Hospital, Ina City, Nagano, Japan;
| | - Koh Yamashita
- Diabetes Center, Aizawa Hospital, Matsumoto City, Nagano, Japan
| | | | - Masanori Shimodaira
- Department of Internal Medicine, Iida Municipal Hospital, Iida City, Nagano, Japan
| | - Naokazu Yokota
- Diabetes Center, Aizawa Hospital, Matsumoto City, Nagano, Japan
| | - Yuka Sato
- Diabetes Center, Aizawa Hospital, Matsumoto City, Nagano, Japan
| | | | - Hideo Koike
- Health Center, Aizawa Hospital, Matsumoto City, Nagano, Japan
| | - Keishi Yamauchi
- Diabetes Center, Shinonoi General Hospital, Nagano City, Nagano, Japan; and
| | - Takuro Shimbo
- Ohta Nishinouchi Hospital, Koriyama City, Fukushima, Japan
| | - Toru Aizawa
- Diabetes Center, Aizawa Hospital, Matsumoto City, Nagano, Japan
| |
Collapse
|
22
|
Shirure VS, Lezia A, Tao A, Alonzo LF, George SC. Low levels of physiological interstitial flow eliminate morphogen gradients and guide angiogenesis. Angiogenesis 2017; 20:493-504. [PMID: 28608153 PMCID: PMC10597324 DOI: 10.1007/s10456-017-9559-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [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: 03/05/2017] [Accepted: 05/30/2017] [Indexed: 01/10/2023]
Abstract
Convective transport can significantly distort spatial concentration gradients. Interstitial flow is ubiquitous throughout living tissue, but our understanding of how interstitial flow affects concentration gradients in biological processes is limited. Interstitial flow is of particular interest for angiogenesis because pathological and physiological angiogenesis is associated with altered interstitial flow, and both interstitial flow and morphogen gradients (e.g., vascular endothelial growth factor, VEGF) can potentially stimulate and guide new blood vessel growth. We designed an in vitro microfluidic platform to simulate 3D angiogenesis in a tissue microenvironment that precisely controls interstitial flow and spatial morphogen gradients. The microvascular tissue was developed from endothelial colony forming cell-derived endothelial cells extracted from cord blood and stromal fibroblasts in a fibrin extracellular matrix. Pressure in the microfluidic lines was manipulated to control the interstitial flow. A mathematical model of mass and momentum transport, and experimental studies with fluorescently labeled dextran were performed to validate the platform. Our data demonstrate that at physiological interstitial flow (0.1-10 μm/s), morphogen gradients were eliminated within hours, and angiogenesis demonstrated a striking bias in the opposite direction of interstitial flow. The interstitial flow-directed angiogenesis was dependent on the presence of VEGF, and the effect was mediated by αvβ3 integrin. We conclude that under physiological conditions, growth factors such as VEGF and fluid forces work together to initiate and spatially guide angiogenesis.
Collapse
Affiliation(s)
- Venktesh S Shirure
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Andrew Lezia
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Arnold Tao
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Luis F Alonzo
- Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA
| | - Steven C George
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Department of Energy, Environment, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| |
Collapse
|
23
|
Parkes M, Cann P, Jeffers J. Real-time observation of fluid flows in tissue during stress relaxation using Raman spectroscopy. J Biomech 2017; 60:261-265. [PMID: 28673665 DOI: 10.1016/j.jbiomech.2017.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 02/21/2017] [Revised: 06/07/2017] [Accepted: 06/13/2017] [Indexed: 11/19/2022]
Abstract
This paper outlines a technique to measure fluid levels in articular cartilage tissue during an unconfined stress relaxation test. A time series of Raman spectrum were recorded during relaxation and the changes in the specific Raman spectral bands assigned to water and protein were monitored to determine the fluid content of the tissue. After 1000s unconfined compression the fluid content of the tissue is reduced by an average of 3.9%±1.7%. The reduction in fluid content during compression varies between samples but does not significantly increase with increasing strain. Further development of this technique will allow mapping of fluid distribution and flows during dynamic testing making it a powerful tool to understand the role of interstitial fluid in the functional performance of cartilage.
Collapse
Affiliation(s)
- Maria Parkes
- Imperial College London, London, United Kingdom.
| | | | | |
Collapse
|
24
|
Halldorsdottir VG, Dave JK, Marshall A, Forsberg AI, Fox TB, Eisenbrey JR, Machado P, Liu JB, Merton DA, Forsberg F. Subharmonic-Aided Pressure Estimation for Monitoring Interstitial Fluid Pressure in Tumors: Calibration and Treatment with Paclitaxel in Breast Cancer Xenografts. Ultrasound Med Biol 2017; 43:1401-1410. [PMID: 28433436 PMCID: PMC6082419 DOI: 10.1016/j.ultrasmedbio.2017.02.011] [Citation(s) in RCA: 12] [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: 10/25/2016] [Revised: 01/31/2017] [Accepted: 02/09/2017] [Indexed: 05/07/2023]
Abstract
Interstitial fluid pressure (IFP) in rats with breast cancer xenografts was non-invasively estimated using subharmonic-aided pressure estimation (SHAPE) versus an invasive pressure monitor. Moreover, monitoring of IFP changes after chemotherapy was assessed. Eighty-nine rats (calibration n = 25, treatment n = 64) were injected with 5 × 106 breast cancer cells (MDA-MB-231). Radiofrequency signals were acquired (39 rats successfully imaged) with a Sonix RP scanner (BK Ultrasound, Richmond, BC, Canada) using a linear array (L9-4, transmit/receive: 8/4 MHz) after administration of Definity (Lantheus Medical Imaging, North Billerica, MA, USA; 180 μL/kg) and compared with readings from an invasive pressure monitor (Stryker, Berkshire, UK). An inverse linear relationship was established between tumor IFP and SHAPE (y = -1.06x + 28.27, r = -0.69, p = 0.01) in the calibration group. Use of this relationship in the treatment group resulted in r = 0.74 (p < 0.05) between measured (pressure monitor) and SHAPE-estimated IFP (average error: 6.24 mmHg). No significant before/after differences were observed with respect to paclitaxel treatment (5 mg/kg, Mayne Pharma, Paramus, NJ, USA) with either method (p ≥ 0.15).
Collapse
Affiliation(s)
- Valgerdur G Halldorsdottir
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA
| | - Jaydev K Dave
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Andrew Marshall
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA
| | - Anya I Forsberg
- Plymouth Whitemarsh High School, Plymouth Meeting, Pennsylvania, USA
| | - Traci B Fox
- Department of Radiologic Sciences, Jefferson College of Health Professions, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - John R Eisenbrey
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Priscilla Machado
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ji-Bin Liu
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Daniel A Merton
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Flemming Forsberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
25
|
Cooper BG, Lawson TB, Snyder BD, Grinstaff MW. Reinforcement of articular cartilage with a tissue-interpenetrating polymer network reduces friction and modulates interstitial fluid load support. Osteoarthritis Cartilage 2017; 25:1143-1149. [PMID: 28285000 PMCID: PMC5726233 DOI: 10.1016/j.joca.2017.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 11/24/2016] [Revised: 02/12/2017] [Accepted: 03/01/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Osteoarthritis (OA) is associated with increased articular cartilage hydraulic permeability and decreased maintenance of high interstitial fluid load support (IFLS) during articulation, resulting in increased friction on the cartilage solid matrix. This study assesses frictional response following in situ synthesis of an interpenetrating polymer network (IPN) designed to mimic glycosaminoglycans (GAGs) depleted during OA. METHODS Cylindrical osteochondral explants containing various interpenetrating polymer concentrations were subjected to a torsional friction test under unconfined creep compression. Time-varying coefficient of friction, compressive engineering strain, and normalized strain values (ε/εeq) were calculated and analyzed. RESULTS The polymer network reduced friction coefficient over the duration of the friction test, with statistically significantly reduced friction coefficients (95% confidence interval 14-34% reduced) at equilibrium compressive strain upon completion of the test (P = 0.015). A positive trend was observed relating polymer network concentration with magnitude of friction reduction compared to non-treated tissue. CONCLUSION The cartilage-interpenetrating polymer treatment improves lubrication by augmenting the biphasic tissue's interstitial fluid phase, and additionally improves the friction dissipation of the tissue's solid matrix. This technique demonstrates potential as a therapy to augment tribological function of articular cartilage.
Collapse
Affiliation(s)
- B G Cooper
- Department of Chemistry, Boston University, Boston, MA, USA; Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| | - T B Lawson
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Mechanical Engineering, Boston University, Boston, MA, USA.
| | - B D Snyder
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Biomedical Engineering, Boston University, Boston, MA, USA; Department of Medicine, Boston University, Boston, MA, USA; Department of Orthopaedic Surgery, Boston Children's Hospital, Boston, MA, USA.
| | - M W Grinstaff
- Department of Chemistry, Boston University, Boston, MA, USA; Department of Biomedical Engineering, Boston University, Boston, MA, USA; Department of Medicine, Boston University, Boston, MA, USA.
| |
Collapse
|
26
|
Koppelmans V, Pasternak O, Bloomberg JJ, Dios YED, Wood SJ, Riascos R, Reuter-Lorenz PA, Kofman IS, Mulavara AP, Seidler RD. Intracranial Fluid Redistribution But No White Matter Microstructural Changes During a Spaceflight Analog. Sci Rep 2017; 7:3154. [PMID: 28600534 PMCID: PMC5466616 DOI: 10.1038/s41598-017-03311-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [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: 01/19/2017] [Accepted: 04/25/2017] [Indexed: 01/01/2023] Open
Abstract
The neural correlates of spaceflight-induced sensorimotor impairments are unknown. Head down-tilt bed rest (HDBR) serves as a microgravity analog because it mimics the headward fluid shift and axial body unloading of spaceflight. We investigated focal brain white matter (WM) changes and fluid shifts during 70 days of 6° HDBR in 16 subjects who were assessed pre (2x), during (3x), and post-HDBR (2x). Changes over time were compared to those in control subjects (n = 12) assessed four times over 90 days. Diffusion MRI was used to assess WM microstructure and fluid shifts. Free-Water Imaging was used to quantify distribution of intracranial extracellular free water (FW). Additionally, we tested whether WM and FW changes correlated with changes in functional mobility and balance measures. HDBR resulted in FW increases in fronto-temporal regions and decreases in posterior-parietal regions that largely recovered by two weeks post-HDBR. WM microstructure was unaffected by HDBR. FW decreases in the post-central gyrus and precuneus correlated negatively with balance changes. We previously reported that gray matter increases in these regions were associated with less HDBR-induced balance impairment, suggesting adaptive structural neuroplasticity. Future studies are warranted to determine causality and underlying mechanisms.
Collapse
Affiliation(s)
- Vincent Koppelmans
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States
| | - Ofer Pasternak
- Departments of Psychiatry and Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | | | | | - Scott J Wood
- NASA Johnson Space Center, Houston, TX, United States
- Azusa Pacific University, Azusa, CA, United States
| | - Roy Riascos
- The University of Texas Health Science Center, Houston, TX, United States
| | | | | | | | - Rachael D Seidler
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States.
- Department of Psychology, University of Michigan, Ann Arbor, MI, United States.
- Neuroscience Program, University of Michigan, Ann Arbor, MI, United States.
| |
Collapse
|
27
|
Udo A, Goodlad C, Davenport A. Impact of Diabetes on Extracellular Volume Status in Patients Initiating Peritoneal Dialysis. Am J Nephrol 2017; 46:18-25. [PMID: 28564640 DOI: 10.1159/000477326] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [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: 01/09/2017] [Accepted: 01/31/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Recent reports have highlighted that diabetic patients with kidney failure are at increased risk of technique failure and transfer to haemodialysis within 90 days of initiating peritoneal dialysis (PD). We wished to determine whether there were differences between diabetic and non-diabetic patients within the first 3 months of starting PD. METHODS We reviewed results of corresponding bioimpedance and the 1st test of peritoneal membrane function (PET) in consecutive patients, 6-10 weeks after initiating PD electively. RESULTS Adult patients numbering 386 - 230 males (59.6%), 152 (39.4%) diabetic, 188 (48.7%) white, mean age 57.3 ±16.9 years - were studied. Although weight, residual renal function and peritoneal clearances were not different, diabetic patients had greater extracellular water to total body water (ECW/TBW; 40.4 ± 1.1 vs. 39.2 ± 1.4) and % ECW excess (9.6 [6.3-12.3] vs. 4.9 [0.7-8.9]), lower serum albumin (35.2 ± 4.7 vs. 37.8 ± 4.9 g/L), greater fat mass index (9.5 ± 4.2 vs. 7.7 ± 4.2), and although mean arterial blood pressure was similar, arterial pulse pressure was greater (66.9 ± 10.8 vs. 54.3 ± 17.3 mm Hg, all p < 0.001). On multivariate analysis, glycated haemoglobin was associated with pulse pressure (standardised β 0.24, p < 0.001), N terminal brain natriuretic peptide (β 0.24, p < 0.001), ECW/TBW (β 0.19, p = 0.012) and negatively with serum albumin (β -0.14, p = 0.033) and creatinine (β -0.18, p = 0.02). CONCLUSION Diabetic patients electively starting PD were found to have greater ECW/TBW ratios and ECW excess 6-10 weeks after starting PD compared to non-diabetics, despite similar PET. Increased ECW could predispose diabetic patients to be at greater risk of volume overload.
Collapse
Affiliation(s)
- Aniema Udo
- Dialysis Unit, University of Uyo Teaching Hospital, Akwa Ibom State, Nigeria
| | | | | |
Collapse
|
28
|
Schain AJ, Melo-Carrillo A, Strassman AM, Burstein R. Cortical Spreading Depression Closes Paravascular Space and Impairs Glymphatic Flow: Implications for Migraine Headache. J Neurosci 2017; 37:2904-2915. [PMID: 28193695 PMCID: PMC5354333 DOI: 10.1523/jneurosci.3390-16.2017] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [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: 11/01/2016] [Revised: 01/19/2017] [Accepted: 01/23/2017] [Indexed: 01/03/2023] Open
Abstract
Functioning of the glymphatic system, a network of paravascular tunnels through which cortical interstitial solutes are cleared from the brain, has recently been linked to sleep and traumatic brain injury, both of which can affect the progression of migraine. This led us to investigate the connection between migraine and the glymphatic system. Taking advantage of a novel in vivo method we developed using two-photon microscopy to visualize the paravascular space (PVS) in naive uninjected mice, we show that a single wave of cortical spreading depression (CSD), an animal model of migraine aura, induces a rapid and nearly complete closure of the PVS around surface as well as penetrating cortical arteries and veins lasting several minutes, and gradually recovering over 30 min. A temporal mismatch between the constriction or dilation of the blood vessel lumen and the closure of the PVS suggests that this closure is not likely to result from changes in vessel diameter. We also show that CSD impairs glymphatic flow, as indicated by the reduced rate at which intraparenchymally injected dye was cleared from the cortex to the PVS. This is the first observation of a PVS closure in connection with an abnormal cortical event that underlies a neurological disorder. More specifically, the findings demonstrate a link between the glymphatic system and migraine, and suggest a novel mechanism for regulation of glymphatic flow.SIGNIFICANCE STATEMENT Impairment of brain solute clearance through the recently described glymphatic system has been linked with traumatic brain injury, prolonged wakefulness, and aging. This paper shows that cortical spreading depression, the neural correlate of migraine aura, closes the paravascular space and impairs glymphatic flow. This closure holds the potential to define a novel mechanism for regulation of glymphatic flow. It also implicates the glymphatic system in the altered cortical and endothelial functioning of the migraine brain.
Collapse
Affiliation(s)
- Aaron J Schain
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, and
- Harvard Medical School, Boston, Massachusetts 02215
| | - Agustin Melo-Carrillo
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, and
- Harvard Medical School, Boston, Massachusetts 02215
| | - Andrew M Strassman
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, and
- Harvard Medical School, Boston, Massachusetts 02215
| | - Rami Burstein
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, and
- Harvard Medical School, Boston, Massachusetts 02215
| |
Collapse
|
29
|
İlhan TT, Uçar MG, Pekin AT, Yılmaz SA, Kerimoğlu ÖS, Çelik Ç. Does lymphadenectomy have influence on postoperative body fluid distribution? Eur J Obstet Gynecol Reprod Biol 2017; 212:182-185. [PMID: 28236490 DOI: 10.1016/j.ejogrb.2017.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 12/15/2016] [Revised: 02/05/2017] [Accepted: 02/11/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE We compared the fluid volume parameters in women undergoing gynaecological surgery for benign and malignant conditions before and after surgery using bioelectrical impedance vectors. STUDY DESIGN A total of 181 patients were enrolled. In all, 89 patients had surgery for benign conditions and 92 patients underwent oncological procedures, including lymph node dissection, for malignant diseases. Bioelectrical impedance analysis (BIA) parameters were measured on the day of hospitalisation before any treatment and at 24h and 1 month after the surgical intervention. The BIA parameters measured included extracellular water (ECW), intracellular water (ICW), and total body water (TBW). RESULTS TBW increased significantly 1 month after surgery in all cases (p<0,05 in both group). ECW was significantly higher (p<0.05) and ICW was significantly lower (p<0,05) in the malignant group than the benign group. CONCLUSION Radical gynaecological surgeries, including lymph node dissection, have a greater effect on body water distribution than surgeries performed for benign conditions.
Collapse
Affiliation(s)
| | - Mustafa Gazi Uçar
- Selçuk University, Faculty of Medicine, Department of Obstetrics and Gynecology, 42075, Konya, Turkey.
| | - Aybike Tazegül Pekin
- Selçuk University, Faculty of Medicine, Department of Obstetrics and Gynecology, 42075, Konya, Turkey.
| | - Setenay Arzu Yılmaz
- Selçuk University, Faculty of Medicine, Department of Obstetrics and Gynecology, 42075, Konya, Turkey.
| | - Özlem Seçilmiş Kerimoğlu
- Selçuk University, Faculty of Medicine, Department of Obstetrics and Gynecology, 42075, Konya, Turkey.
| | - Çetin Çelik
- Selçuk University, Faculty of Medicine, Department of Obstetrics and Gynecology, Gynecologic Oncology Unit, 42075, Konya, Turkey.
| |
Collapse
|
30
|
Hitscherich K, Smith K, Cuoco JA, Ruvolo KE, Mancini JD, Leheste JR, Torres G. The Glymphatic-Lymphatic Continuum: Opportunities for Osteopathic Manipulative Medicine. J Osteopath Med 2017; 116:170-7. [PMID: 26927910 DOI: 10.7556/jaoa.2016.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The brain has long been thought to lack a lymphatic drainage system. Recent studies, however, show the presence of a brain-wide paravascular system appropriately named the glymphatic system based on its similarity to the lymphatic system in function and its dependence on astroglial water flux. Besides the clearance of cerebrospinal fluid and interstitial fluid, the glymphatic system also facilitates the clearance of interstitial solutes such as amyloid-β and tau from the brain. As cerebrospinal fluid and interstitial fluid are cleared through the glymphatic system, eventually draining into the lymphatic vessels of the neck, this continuous fluid circuit offers a paradigm shift in osteopathic manipulative medicine. For instance, manipulation of the glymphatic-lymphatic continuum could be used to promote experimental initiatives for nonpharmacologic, noninvasive management of neurologic disorders. In the present review, the authors describe what is known about the glymphatic system and identify several osteopathic experimental strategies rooted in a mechanistic understanding of the glymphatic-lymphatic continuum.
Collapse
|
31
|
Piotrowski-Daspit AS, Simi AK, Pang MF, Tien J, Nelson CM. A 3D Culture Model to Study How Fluid Pressure and Flow Affect the Behavior of Aggregates of Epithelial Cells. Methods Mol Biol 2017; 1501:245-257. [PMID: 27796957 DOI: 10.1007/978-1-4939-6475-8_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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] [Indexed: 12/13/2022]
Abstract
Cells are surrounded by mechanical stimuli in their microenvironment. It is important to determine how cells respond to the mechanical information that surrounds them in order to understand both development and disease progression, as well as to be able to predict cell behavior in response to physical stimuli. Here we describe a protocol to determine the effects of interstitial fluid flow on the migratory behavior of an aggregate of epithelial cells in a three-dimensional (3D) culture model. This protocol includes detailed methods for the fabrication of a 3D cell culture chamber with hydrostatic pressure control, the culture of epithelial cells as an aggregate in a collagen gel, and the analysis of collective cell behavior in response to pressure-driven flow.
Collapse
Affiliation(s)
- Alexandra S Piotrowski-Daspit
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
| | - Allison K Simi
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
| | - Mei-Fong Pang
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA
| | - Joe Tien
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
- Division of Materials Science and Engineering, Boston University, Boston, MA, 02215, USA
| | - Celeste M Nelson
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, William Street, Princeton, NJ, 08544, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
| |
Collapse
|
32
|
Abstract
The submandibular gland is a cell-rich encapsulated organ with high transport of fluid through the interstitial space during salivation. We hypothesized that the gland is a low-compliant tissue, i.e., that a modest increase in fluid volume will produce a rise in interstitial fluid pressure (IFP) counteracting fluid filtration into the interstitium. To test this hypothesis, we measured IFP with micropipettes and glandular blood flow (GBF) with a laser-Doppler flowmeter during changes in perfusion. Clamping of the carotid artery or the jugular vein, or electrical stimulation of the sympathetic or parasympathetic nerve to the gland, induced changes in perfusion. Baseline IFP averaged 3.5 ± 0.5 mm Hg. Clamping of the artery reduced IFP and GBF (−56.5 ± 8.4% and −53.1 ± 6.4%, respectively), whereas clamping of the vein decreased GBF (−21.6 ± 14.3%) and increased IFP (141.2 ± 27.4%). Sympathetic nerve stimulation reduced both parameters (−86.9 ± 16.5% and −74.4 ± 7.0%, respectively). In contrast, stimulation of the parasympathetic nerve elicited an increase in GBF (133.2 ± 5.9%) and in IFP (173.3 ± 41.4%). Thus, changes in vascular volume led to concomitant changes in IFP consistent with low tissue compliance, a phenomenon of importance for fluid volume regulation.
Collapse
Affiliation(s)
- E Berggreen
- Department of Physiology, Jonas Lies Vei 91, University of Bergen, N-5009 Bergen, Norway.
| | | | | |
Collapse
|
33
|
Halnes G, Mäki-Marttunen T, Keller D, Pettersen KH, Andreassen OA, Einevoll GT. Effect of Ionic Diffusion on Extracellular Potentials in Neural Tissue. PLoS Comput Biol 2016; 12:e1005193. [PMID: 27820827 PMCID: PMC5098741 DOI: 10.1371/journal.pcbi.1005193] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [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: 03/19/2016] [Accepted: 10/11/2016] [Indexed: 01/06/2023] Open
Abstract
Recorded potentials in the extracellular space (ECS) of the brain is a standard measure of population activity in neural tissue. Computational models that simulate the relationship between the ECS potential and its underlying neurophysiological processes are commonly used in the interpretation of such measurements. Standard methods, such as volume-conductor theory and current-source density theory, assume that diffusion has a negligible effect on the ECS potential, at least in the range of frequencies picked up by most recording systems. This assumption remains to be verified. We here present a hybrid simulation framework that accounts for diffusive effects on the ECS potential. The framework uses (1) the NEURON simulator to compute the activity and ionic output currents from multicompartmental neuron models, and (2) the electrodiffusive Kirchhoff-Nernst-Planck framework to simulate the resulting dynamics of the potential and ion concentrations in the ECS, accounting for the effect of electrical migration as well as diffusion. Using this framework, we explore the effect that ECS diffusion has on the electrical potential surrounding a small population of 10 pyramidal neurons. The neural model was tuned so that simulations over ∼100 seconds of biological time led to shifts in ECS concentrations by a few millimolars, similar to what has been seen in experiments. By comparing simulations where ECS diffusion was absent with simulations where ECS diffusion was included, we made the following key findings: (i) ECS diffusion shifted the local potential by up to ∼0.2 mV. (ii) The power spectral density (PSD) of the diffusion-evoked potential shifts followed a 1/f2 power law. (iii) Diffusion effects dominated the PSD of the ECS potential for frequencies up to several hertz. In scenarios with large, but physiologically realistic ECS concentration gradients, diffusion was thus found to affect the ECS potential well within the frequency range picked up in experimental recordings.
Collapse
Affiliation(s)
- Geir Halnes
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Tuomo Mäki-Marttunen
- NORMENT, KG Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Daniel Keller
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Klas H. Pettersen
- Letten Centre and GliaLab, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Centre for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | - Ole A. Andreassen
- NORMENT, KG Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Gaute T. Einevoll
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway
- Department of Physics, University of Oslo, Oslo, Norway
| |
Collapse
|
34
|
Gao J, Hentel K, Kazam J, Min R. Ultrasound Strain Relaxation Time Ratio: A Quantitative Marker for the Assessment of Cortical Inflammation/Edema in Renal Allografts. Ultraschall Med 2016; 37:509-515. [PMID: 26251993 DOI: 10.1055/s-0034-1385282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Purpose: To evaluate the ability of ultrasound strain relaxation time ratio to assess cortical inflammation/edema in renal allografts. Materials and Methods: We prospectively assessed renal allograft cortical inflammation/edema in 16 renal transplants using ultrasound elasticity imaging and correlated the findings with kidney biopsy. Strain relaxation times in the renal cortex and reference soft tissue were produced by free-hand compression with the ultrasound transducer and estimated with 2 D speckle tracking. Compression was performed in 3-second compression-relaxation cycles (push for 1 second, constant pressure for 1 second, and release for 1 second). We propose a strain relaxation time ratio (time of cortical strain to return to zero/time of the reference strain return to zero) to assess the relationship of compression-induced time-dependent strain relaxation in the cortex and reference tissue. 16 patients were divided into a group with ≤ 25 % (n = 8) and a group with > 26 % (n = 8) cortical inflammation/edema based on the Banff score. A t-test was used to examine the difference in the strain relaxation time ratio between the two groups. The diagnostic accuracy, inter-rater reliability, and reproducibility of this technique in discriminating between the groups were tested. Results: The strain relaxation time ratio of cortex/reference tissue was significantly higher in patients with > 26 % than in patients with ≤ 25 % cortical inflammation/edema (1.15 ± 0.10 vs. 0.91 ± 0.08, P = 0.0002). The strain relaxation time ratio has high reliability (Pearson correlation coefficient, R² = 0.93), reproducibility (intraclass correlation coefficient = 0.98, P = 0.000), and accuracy (area under curve = 1) in determining > 26 % renal cortical inflammation/edema. Conclusion: The strain relaxation time ratio of cortex/reference tissue can be used as a quantitative marker for the assessment of cortical inflammation/edema in renal allografts.
Collapse
|
35
|
Marcoli M, Agnati LF, Benedetti F, Genedani S, Guidolin D, Ferraro L, Maura G, Fuxe K. On the role of the extracellular space on the holistic behavior of the brain. Rev Neurosci 2016; 26:489-506. [PMID: 26103627 DOI: 10.1515/revneuro-2015-0007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/11/2015] [Indexed: 12/18/2022]
Abstract
Multiple players are involved in the brain integrative action besides the classical neuronal and astrocyte networks. In the past, the concept of complex cellular networks has been introduced to indicate that all the cell types in the brain can play roles in its integrative action. Intercellular communication in the complex cellular networks depends not only on well-delimited communication channels (wiring transmission) but also on diffusion of signals in physically poorly delimited extracellular space pathways (volume transmission). Thus, the extracellular space and the extracellular matrix are the main players in the intercellular communication modes in the brain. Hence, the extracellular matrix is an 'intelligent glue' that fills the brain and, together with the extracellular space, contributes to the building-up of the complex cellular networks. In addition, the extracellular matrix is part of what has been defined as the global molecular network enmeshing the entire central nervous system, and plays important roles in synaptic contact homeostasis and plasticity. From these premises, a concept is introduced that the global molecular network, by enmeshing the central nervous system, contributes to the brain holistic behavior. Furthermore, it is suggested that plastic 'brain compartments' can be detected in the central nervous system based on the astrocyte three-dimensional tiling of the brain volume and on the existence of local differences in cell types and extracellular space fluid and extracellular matrix composition. The relevance of the present view for neuropsychiatry is discussed. A glossary box with terms and definitions is provided.
Collapse
|
36
|
MATSUMAE M, SATO O, HIRAYAMA A, HAYASHI N, TAKIZAWA K, ATSUMI H, SORIMACHI T. Research into the Physiology of Cerebrospinal Fluid Reaches a New Horizon: Intimate Exchange between Cerebrospinal Fluid and Interstitial Fluid May Contribute to Maintenance of Homeostasis in the Central Nervous System. Neurol Med Chir (Tokyo) 2016; 56:416-41. [PMID: 27245177 PMCID: PMC4945600 DOI: 10.2176/nmc.ra.2016-0020] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [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: 01/20/2016] [Accepted: 03/20/2016] [Indexed: 12/23/2022] Open
Abstract
Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.
Collapse
Affiliation(s)
- Mitsunori MATSUMAE
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| | | | - Akihiro HIRAYAMA
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| | - Naokazu HAYASHI
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| | - Ken TAKIZAWA
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| | - Hideki ATSUMI
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| | - Takatoshi SORIMACHI
- Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa
| |
Collapse
|
37
|
Kiba K, Hirayama A, Yoshikawa M, Yamamoto Y, Torimoto K, Fujimoto K, Uemura H. [The Influence of Change in Body Water Distribution Caused by Changing Position Upon Nocturia in Older Men]. Hinyokika Kiyo 2016; 62:243-248. [PMID: 27320115] [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: 06/06/2023]
Abstract
A total of 29 men 60 years and older (mean age 74 years) who complained at least once about nocturnal voiding and were diagnosed with nocturnal polyuria in the frequency volume chart (FVC) were enrolled in this study. Body water was measured by bioelectric impedance analysis just after lying down at 4 pm and after raising legs 30 minutes later. Nocturnal urine production was measured by FVC, and urine production per unit of time at first nocturnal voiding (urine volume at first nocturnal voiding/hours of undisturbed sleep (HUS) : UFN/HUS), urine production per unit of time during sleep (total nocturnal urine volume/hours of sleep : TNV/HS), etc was evaluated. Extra cellular water (ECW) of 0.19 l (4.0%) in legs was reduced caused by body position changing. There was a significant positive correlation between the amount of ECW in legs and UFN/HUS, TNV/HS (r=0. 57, p=0.001 ; r=0. 38, p=0.042, respectively). Moreover, UFN/HUS had a significant correlation with soft lean mass in legs, ECW in legs and daytime water intake. This study suggested that a change in leg fluids caused by a change in position results in increased urine production and decreased HUS.
Collapse
Affiliation(s)
- Keisuke Kiba
- The Department of Urology, Kinki University of Medicine, Nara Hospital
| | - Akihide Hirayama
- The Department of Urology, Kinki University of Medicine, Nara Hospital
| | | | - Yutaka Yamamoto
- The Department of Urology, Kinki University of Medicine, Nara Hospital
| | | | | | | |
Collapse
|
38
|
Sanders JE, Moehring MA, Rothlisberger TM, Phillips RH, Hartley T, Dietrich CR, Redd CB, Gardner DW, Cagle JC. A Bioimpedance Analysis Platform for Amputee Residual Limb Assessment. IEEE Trans Biomed Eng 2015; 63:1760-70. [PMID: 26595906 DOI: 10.1109/tbme.2015.2502060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE The objective of this research was to develop a bioimpedance platform for monitoring fluid volume in residual limbs of people with trans-tibial limb loss using prostheses. METHODS A customized multifrequency current stimulus profile was sent to thin flat electrodes positioned on the thigh and distal residual limb. The applied current signal and sensed voltage signals from four pairs of electrodes located on the anterior and posterior surfaces were demodulated into resistive and reactive components. An established electrical model (Cole) and segmental limb geometry model were used to convert results to extracellular and intracellular fluid volumes. Bench tests and testing on amputee participants were conducted to optimize the stimulus profile and electrode design and layout. RESULTS The proximal current injection electrode needed to be at least 25 cm from the proximal voltage sensing electrode. A thin layer of hydrogel needed to be present during testing to ensure good electrical coupling. Using a burst duration of 2.0 ms, intermission interval of 100 μs, and sampling delay of 10 μs at each of 24 frequencies except 5 kHz, which required a 200-μs sampling delay, the system achieved a sampling rate of 19.7 Hz. CONCLUSION The designed bioimpedance platform allowed system settings and electrode layouts and positions to be optimized for amputee limb fluid volume measurement. SIGNIFICANCE The system will be useful toward identifying and ranking prosthetic design features and participant characteristics that impact residual limb fluid volume.
Collapse
|
39
|
Alonzo LF, Moya ML, Shirure VS, George SC. Microfluidic device to control interstitial flow-mediated homotypic and heterotypic cellular communication. Lab Chip 2015; 15:3521-9. [PMID: 26190172 PMCID: PMC4855298 DOI: 10.1039/c5lc00507h] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Tissue engineering can potentially recreate in vivo cellular microenvironments in vitro for an array of applications such as biological inquiry and drug discovery. However, the majority of current in vitro systems still neglect many biological, chemical, and mechanical cues that are known to impact cellular functions such as proliferation, migration, and differentiation. To address this gap, we have developed a novel microfluidic device that precisely controls the spatial and temporal interactions between adjacent three-dimensional cellular environments. The device consists of four interconnected microtissue compartments (~0.1 mm(3)) arranged in a square. The top and bottom pairs of compartments can be sequentially loaded with discrete cellularized hydrogels creating the opportunity to investigate homotypic (left to right or x-direction) and heterotypic (top to bottom or y-direction) cell-cell communication. A controlled hydrostatic pressure difference across the tissue compartments in both x and y direction induces interstitial flow and modulates communication via soluble factors. To validate the biological significance of this novel platform, we examined the role of stromal cells in the process of vasculogenesis. Our device confirms previous observations that soluble mediators derived from normal human lung fibroblasts (NHLFs) are necessary to form a vascular network derived from endothelial colony forming cell-derived endothelial cells (ECFC-ECs). We conclude that this platform could be used to study important physiological and pathological processes that rely on homotypic and heterotypic cell-cell communication.
Collapse
Affiliation(s)
- Luis F. Alonzo
- Department of Biomedical Engineering, University of California, Irvine, CA 92697
| | - Monica L. Moya
- Department of Biomedical Engineering, University of California, Irvine, CA 92697
| | - Venktesh S. Shirure
- Department of Biomedical Engineering, Washington University in St. Louis, MO 63130
| | - Steven C. George
- Department of Biomedical Engineering, Washington University in St. Louis, MO 63130
- Department of Energy, Environment, and Chemical Engineering, Washington University in St. Louis, MO 63130
| |
Collapse
|
40
|
Guthe HJT, Indrebø M, Nedrebø T, Norgård G, Wiig H, Berg A. Interstitial fluid colloid osmotic pressure in healthy children. PLoS One 2015; 10:e0122779. [PMID: 25853713 PMCID: PMC4390290 DOI: 10.1371/journal.pone.0122779] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [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: 09/28/2014] [Accepted: 02/07/2015] [Indexed: 11/19/2022] Open
Abstract
Objective The colloid osmotic pressure (COP) of plasma and interstitial fluid play important roles in transvascular fluid exchange. COP values for monitoring fluid balance in healthy and sick children have not been established. This study set out to determine reference values of COP in healthy children. Materials and Methods COP in plasma and interstitial fluid harvested from nylon wicks was measured in 99 healthy children from 2 to 10 years of age. Nylon wicks were implanted subcutaneously in arm and leg while patients were sedated and intubated during a minor surgical procedure. COP was analyzed in a colloid osmometer designed for small fluid samples. Results The mean plasma COP in all children was 25.6 ± 3.3 mmHg. Arbitrary division of children in four different age groups, showed no significant difference in plasma or interstitial fluid COP values for patients less than 8 years, whereas patients of 8-10 years had significant higher COP both in plasma and interstitial fluid. There were no gender difference or correlation between COP in interstitial fluid sampled from arm and leg and no significant effect on interstitial COP of gravity. Prolonged implantation time did not affect interstitial COP. Conclusion Plasma and interstitial COP in healthy children are comparable to adults and COP seems to increase with age in children. Knowledge of the interaction between colloid osmotic forces can be helpful in diseases associated with fluid imbalance and may be crucial in deciding different fluid treatment options. Trial Registration ClinicalTrials.gov NCT01044641
Collapse
Affiliation(s)
- Hans Jørgen Timm Guthe
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- * E-mail:
| | - Marianne Indrebø
- Department of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Torbjørn Nedrebø
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Occupational Medicine, Hyperbaric Medical Unit, Haukeland University Hospital, Bergen, Norway
| | - Gunnar Norgård
- Department of Clinical Medicine, Faculty of Medicine, Section for Pediatric heart-, lung- and allergic diseases, University of Oslo, Oslo, Norway
| | - Helge Wiig
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Ansgar Berg
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| |
Collapse
|
41
|
Abstract
Hyponatremia is defined as a serum below 135 mmol/l and is the most frequent electrolytes disorder. The treatment is essential because hyponatremia is associated with increased morbidity and mortality. There are multiple aetiologies associated with this challenging diagnosis. The correct one must be established in order to manage this disorder appropriately. Serum and urine osmolalities, serum sodium concentration and evaluation of extracellular fluid volume are necessary for the diagnosis. The rate of correction of hyponatremia should be closely monitored to avoid cerebral complications. This article reviews the recommended approaches for the diagnosis and treatment of hyponatremia.
Collapse
Affiliation(s)
- Lena Berchtold
- Service de Médecine Interne Générale, Hôpitaux Universitaire de Genève
| | | | - Belen Ponte
- Service de Néphrologie, Hôpitaux Universitaire de Genève
| |
Collapse
|
42
|
Abstract
There are two main types of fluid in bone tissue, blood and interstitial fluid. The chemical composition of these fluids varies with time and location in bone. Blood arrives through the arterial system containing oxygen and other nutrients and the blood components depart via the venous system containing less oxygen and reduced nutrition. Within the bone, as within other tissues, substances pass from the blood through the arterial walls into the interstitial fluid. The movement of the interstitial fluid carries these substances to the cells within the bone and, at the same time, carries off the waste materials from the cells. Bone tissue would not live without these fluid movements. The development of a model for poroelastic materials with hierarchical pore space architecture for the description of blood flow and interstitial fluid flow in living bone tissue is reviewed. The model is applied to the problem of determining the exchange of pore fluid between the vascular porosity and the lacunar-canalicular porosity in bone tissue due to cyclic mechanical loading and blood pressure. These results are basic to the understanding of interstitial flow in bone tissue that, in turn, is basic to understanding of nutrient transport from the vasculature to the bone cells buried in the bone tissue and to the process of mechanotransduction by these cells.
Collapse
Affiliation(s)
- Stephen C Cowin
- Department of Mechanical Engineering, San Diego State University, San Diego, CA 92182, USA.
| | - Luis Cardoso
- The Department of Biomedical Engineering, Grove School of Engineering of The City College, The Graduate School of The City University of New York, New York, NY 10031, USA
| |
Collapse
|
43
|
Nowak J, Nowak B, Kaczmarek M. Skinfold creep under load of caliper. Linear visco- and poroelastic model simulations. Acta Bioeng Biomech 2015; 17:39-48. [PMID: 26899777] [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: 06/05/2023]
Abstract
PURPOSE This paper addresses the diagnostic idea proposed in [11] to measure the parameter called rate of creep of axillary fold of tissue using modified Harpenden skinfold caliper in order to distinguish normal and edematous tissue. Our simulations are intended to help understanding the creep phenomenon and creep rate parameter as a sensitive indicator of edema existence. The parametric analysis shows the tissue behavior under the external load as well as its sensitivity to changes of crucial hydro-mechanical tissue parameters, e.g., permeability or stiffness. METHODS The linear viscoelastic and poroelastic models of normal (single phase) and oedematous tissue (twophase: swelled tissue with excess of interstitial fluid) implemented in COMSOL Multiphysics environment are used. Simulations are performed within the range of small strains for a simplified fold geometry, material characterization and boundary conditions. The predicted creep is the result of viscosity (viscoelastic model) or pore fluid displacement (poroelastic model) in tissue. RESULTS The tissue deformations, interstitial fluid pressure as well as interstitial fluid velocity are discussed in parametric analysis with respect to elasticity modulus, relaxation time or permeability of tissue. The creep rate determined within the models of tissue is compared and referred to the diagnostic idea in [11]. CONCLUSIONS The results obtained from the two linear models of subcutaneous tissue indicate that the form of creep curve and the creep rate are sensitive to material parameters which characterize the tissue. However, the adopted modelling assumptions point to a limited applicability of the creep rate as the discriminant of oedema.
Collapse
Affiliation(s)
- Joanna Nowak
- Institute of Mechanics and Applied Computer Science, Kazimierz Wielki University Bydgoszcz, Poland
| | - Bartosz Nowak
- Faculty of Civil Engineering, Bauhaus-Universität Weimar, Weimar, Germany
| | - Mariusz Kaczmarek
- Institute of Mechanics and Applied Computer Science, Kazimierz Wielki University Bydgoszcz, Poland
| |
Collapse
|
44
|
Tsai YC, Chiu YW, Kuo HT, Chen SC, Hwang SJ, Chen TH, Kuo MC, Chen HC. Fluid overload, pulse wave velocity, and ratio of brachial pre-ejection period to ejection time in diabetic and non-diabetic chronic kidney disease. PLoS One 2014; 9:e111000. [PMID: 25386836 PMCID: PMC4227653 DOI: 10.1371/journal.pone.0111000] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 04/09/2014] [Accepted: 09/22/2014] [Indexed: 11/19/2022] Open
Abstract
Fluid overload is one of the characteristics in chronic kidney disease (CKD). Changes in extracellular fluid volume are associated with progression of diabetic nephropathy. Not only diabetes but also fluid overload is associated with cardiovascular risk factors The aim of the study was to assess the interaction between fluid overload, diabetes, and cardiovascular risk factors, including arterial stiffness and left ventricular function in 480 patients with stages 4–5 CKD. Fluid status was determined by bioimpedance spectroscopy method, Body Composition Monitor. Brachial-ankle pulse wave velocity (baPWV), as a good parameter of arterial stiffness, and brachial pre-ejection period (bPEP)/brachial ejection time (bET), correlated with impaired left ventricular function were measured by ankle-brachial index (ABI)-form device. Of all patients, 207 (43.9%) were diabetic and 240 (50%) had fluid overload. For non-diabetic CKD, fluid overload was associated with being female (β = –2.87, P = 0.003), heart disease (β = 2.69, P = 0.04), high baPWV (β = 0.27, P = 0.04), low hemoglobin (β = –1.10, P<0.001), and low serum albumin (β = –5.21, P<0.001) in multivariate analysis. For diabetic CKD, fluid overload was associated with diuretics use (β = 3.69, P = 0.003), high mean arterial pressure (β = 0.14, P = 0.01), low bPEP/ET (β = –0.19, P = 0.03), low hemoglobin (β = –1.55, P = 0.001), and low serum albumin (β = –9.46, P<0.001). In conclusion, baPWV is associated with fluid overload in non-diabetic CKD and bPEP/bET is associated with fluid overload in diabetic CKD. Early and accurate assessment of these associated cardiovascular risk factors may improve the effects of entire care in late CKD.
Collapse
Affiliation(s)
- Yi-Chun Tsai
- Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Wen Chiu
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hung-Tien Kuo
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Szu-Chia Chen
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan
| | - Shang-Jyh Hwang
- Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
- Institute of Population Sciences, National Health Research Institutes, Miaoli, Taiwan
| | - Tzu-Hui Chen
- Department of Nursing, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Mei-Chuan Kuo
- Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
- * E-mail:
| | - Hung-Chun Chen
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan
| |
Collapse
|
45
|
Abstract
Cells transduce mechanical forces into biochemical signals; traditionally these processes are thought to occur through direct effects on the cell membrane, the cytoskeleton, or specific transmembrane proteins. In multicellular tissues mechanical forces alter intercellular spacing through redistribution of interstitial fluid. Recent morphological and biochemical observations, bolstered by analytical modeling, support a new paradigm for mechanotransduction arising from constitutive growth factor shedding into a dynamically regulated interstitial volume.
Collapse
Affiliation(s)
- Daniel J Tschumperlin
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA.
| |
Collapse
|
46
|
Chen C, Li T, Liu J. Letter by Chen et al regarding article, "Role of extracellular RNA in atherosclerotic plaque formation in mice". Circulation 2014; 130:e143. [PMID: 25311623 DOI: 10.1161/circulationaha.113.008468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Chan Chen
- Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Tao Li
- Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
47
|
Abstract
The mechanical microenvironment of solid tumors includes both fluid and solid stresses. These stresses play a crucial role in cancer progression and treatment and have been analyzed rigorously both mathematically and experimentally. The magnitude and spatial distribution of osmotic pressures in tumors, however, cannot be measured experimentally and to our knowledge there is no mathematical model to calculate osmotic pressures in the tumor interstitial space. In this study, we developed a triphasic biomechanical model of tumor growth taking into account not only the solid and fluid phase of a tumor, but also the transport of cations and anions, as well as the fixed charges at the surface of the glycosaminoglycan chains. Our model predicts that the osmotic pressure is negligible compared to the interstitial fluid pressure for values of glycosaminoglycans (GAGs) taken from the literature for sarcomas, melanomas and adenocarcinomas. Furthermore, our results suggest that an increase in the hydraulic conductivity of the tumor, increases considerably the intratumoral concentration of free ions and thus, the osmotic pressure but it does not reach the levels of the interstitial fluid pressure.
Collapse
Affiliation(s)
- Chysovalantis Voutouri
- Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus
| | - Triantafyllos Stylianopoulos
- Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus.
| |
Collapse
|
48
|
Barbosa EJL, Glad CAM, Nilsson AG, Bosaeus N, Nyström HF, Svensson PA, Bengtsson BÅ, Nilsson S, Bosaeus I, Boguszewski CL, Johannsson G. Extracellular water and blood pressure in adults with growth hormone (GH) deficiency: a genotype-phenotype association study. PLoS One 2014; 9:e105754. [PMID: 25157616 PMCID: PMC4144955 DOI: 10.1371/journal.pone.0105754] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 07/28/2014] [Indexed: 12/18/2022] Open
Abstract
Objectives Growth hormone deficiency (GHD) in adults is associated with decreased extracellular water volume (ECW). In response to GH replacement therapy (GHRT), ECW increases and blood pressure (BP) reduces or remains unchanged. Our primary aim was to study the association between polymorphisms in genes related to renal tubular function with ECW and BP before and 1 year after GHRT. The ECW measures using bioimpedance analysis (BIA) and bioimpedance spectroscopy (BIS) were validated against a reference method, the sodium bromide dilution method (Br−). Design and Methods Using a candidate gene approach, fifteen single-nucleotide polymorphisms (SNPs) in nine genes with known impact on renal tubular function (AGT, SCNN1A, SCNN1G, SLC12A1, SLC12A3, KCNJ1, STK39, WNK1 and CASR) were genotyped and analyzed for associations with ECW and BP at baseline and with their changes after 1 year of GHRT in 311 adult GHD patients. ECW was measured with the Br−, BIA, and BIS. Results Both BIA and BIS measurements demonstrated similar ECW results as the reference method. At baseline, after adjustment for sex and BMI, SNP rs2291340 in the SLC12A1 gene was associated with ECW volume in GHD patients (p = 0.039). None of the SNPs influenced the ECW response to GHRT. One SNP in the SLC12A3 gene (rs11643718; p = 0.024) and three SNPs in the SCNN1G gene [rs5723 (p = 0.02), rs5729 (p = 0.016) and rs13331086 (p = 0.035)] were associated with the inter-individual differences in BP levels at baseline. A polymorphism in the calcium-sensing receptor (CASR) gene (rs1965357) was associated with changes in systolic BP after GHRT (p = 0.036). None of these associations remained statistically significant when corrected for multiple testing. Conclusion The BIA and BIS are as accurate as Br− to measure ECW in GHD adults before and during GHRT. Our study provides the first evidence that individual polymorphisms may have clinically relevant effects on ECW and BP in GHD adults.
Collapse
Affiliation(s)
- Edna J. L. Barbosa
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- SEMPR, Servico de Endocrinologia e Metabologia do Hospital de Clínicas da Universidade Federal do Paraná, Curitiba, Brazil
| | - Camilla A. M. Glad
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anna G. Nilsson
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Niklas Bosaeus
- Department of Clinical Nutrition Unit, Sahlgrenska University Hospital, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Helena Filipsson Nyström
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Per-Arne Svensson
- Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bengt-Åke Bengtsson
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Staffan Nilsson
- Institute of Mathematical Sciences, Department of Mathematical Statistics, Chalmers University of Technology, Chalmers, Gothenburg, Sweden
| | - Ingvar Bosaeus
- Department of Clinical Nutrition Unit, Sahlgrenska University Hospital, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Cesar Luiz Boguszewski
- SEMPR, Servico de Endocrinologia e Metabologia do Hospital de Clínicas da Universidade Federal do Paraná, Curitiba, Brazil
| | - Gudmundur Johannsson
- Department of Endocrinology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
| |
Collapse
|
49
|
Bazigou E, Wilson JT, Moore JE. Primary and secondary lymphatic valve development: molecular, functional and mechanical insights. Microvasc Res 2014; 96:38-45. [PMID: 25086182 DOI: 10.1016/j.mvr.2014.07.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [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: 06/11/2014] [Revised: 07/17/2014] [Accepted: 07/22/2014] [Indexed: 01/27/2023]
Abstract
Fluid homeostasis in vertebrates critically relies on the lymphatic system forming a hierarchical network of lymphatic capillaries and collecting lymphatics, for the efficient drainage and transport of extravasated fluid back to the cardiovascular system. Blind-ended lymphatic capillaries employ specialized junctions and anchoring filaments to encourage a unidirectional flow of the interstitial fluid into the initial lymphatic vessels, whereas collecting lymphatics are responsible for the active propulsion of the lymph to the venous circulation via the combined action of lymphatic muscle cells and intraluminal valves. Here we describe recent findings on molecular and physical factors regulating the development and maturation of these two types of valves and examine their role in tissue-fluid homeostasis.
Collapse
Affiliation(s)
- Eleni Bazigou
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
| | - John T Wilson
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - James E Moore
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| |
Collapse
|
50
|
Hompland T, Ellingsen C, Galappathi K, Rofstad EK. Connective tissue of cervical carcinoma xenografts: associations with tumor hypoxia and interstitial fluid pressure and its assessment by DCE-MRI and DW-MRI. Acta Oncol 2014; 53:6-15. [PMID: 23445339 DOI: 10.3109/0284186x.2013.773073] [Citation(s) in RCA: 18] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Abstract Background. A high fraction of stroma in malignant tissues is associated with tumor progression, metastasis, and poor prognosis. Possible correlations between the stromal and physiologic microenvironments of tumors and the potential of dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance imaging (MRI) in quantification of the stromal microenvironment were investigated in this study. Material and methods. CK-160 cervical carcinoma xenografts were used as preclinical tumor model. A total of 43 tumors were included in the study, and of these tumors, 17 were used to search for correlations between the stromal and physiologic microenvironments, 11 were subjected to DCE-MRI, and 15 were subjected to DW-MRI. DCE-MRI and DW-MRI were carried out at 1.5 T with a clinical MR scanner and a slotted tube resonator transceiver coil constructed for mice. Fraction of connective tissue (CTFCol) and fraction of hypoxic tissue (HFPim) were determined by immunohistochemistry. A Millar SPC 320 catheter was used to measure tumor interstitial fluid pressure (IFP). Results. CTFCol showed a positive correlation to IFP and an inverse correlation to HFPim. The apparent diffusion coefficient assessed by DW-MRI was inversely correlated to CTFCol, whereas no correlation was found between DCE-MRI-derived parameters and CTFCol. Conclusion. DW-MRI is a potentially useful method for characterizing the stromal microenvironment of tumors.
Collapse
Affiliation(s)
- Tord Hompland
- Group of Radiation Biology and Tumor Physiology, Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital , Oslo , Norway
| | | | | | | |
Collapse
|