Filters








210 Hits in 4.2 sec

Pathophysiology of Retinal Vein Occlusions [chapter]

David J. Browning
2012 Retinal Vein Occlusions  
Oxygen Exchange in the Retina and Autoregulation The retina exhibits the high rates of glycolysis necessary for the active transport of ions that generate gradients subserving neuronal action potentials  ...  There are oxygen gradients within the retina. • The oxygen tension is highest adjacent to retinal arteries and lowest adjacent to retinal veins.  ... 
doi:10.1007/978-1-4614-3439-9_2 fatcat:f7wloukcgbfmjla7wvr332ed6m

Modelling of hydrogen diffusion in the retina

Wafaa Mansoor, Graeme Hocking, Duncan Farrow
2020 ANZIAM Journal  
Modeling Hydrogen clearance from the retina. ANZIAM J. 59:281–292, 2018. doi:10.1017/S1446181117000426 A. B. Friedland. A mathematical model of transmural transport of oxygen to the retina. Bull.  ...  Choroidal regulation of oxygen supply to the guinea pig retina. In A. G. Hudetz, and D. F. Bruley (Eds.), Oxygen Transport to Tissue XX, pp. 385–389. Springer, 1998. doi:10.1007/978-1-4615-4863-8  ...  This small Peclet number is equivalent to a large α in the 1D model. Here, the diffusion term plays a vital role in the transport of the hydrogen.  ... 
doi:10.21914/anziamj.v61i0.14995 fatcat:jd3e3gf545da7at3a6mrlmi6he

Mathematical methods for modeling the microcirculation

Julia C. Arciero, Paola Causin, Francesca Malgaroli
2017 AIMS Biophysics  
vascular networks, solute transport and delivery to the surrounding tissue, and vessel wall mechanics under passive and active stimuli.  ...  The microcirculation plays a major role in maintaining homeostasis in the body. Alterations or dysfunctions of the microcirculation can lead to several types of serious diseases.  ...  Models of gas transport in the retinal tissue Several models have been developed to estimate oxygen profiles in the avascular region of the retina (outer retina).  ... 
doi:10.3934/biophy.2017.3.362 fatcat:nnsrh43egvhb3jzi3h3mm52lgm

Dynamics of angiogenesis during murine retinal development: a coupled in vivo and in silico study

M. G. Watson, S. R. McDougall, M. A. J. Chaplain, A. H. Devlin, C. A. Mitchell
2012 Journal of the Royal Society Interface  
factor (PDGF)-A results in the formation of a dense scaffold on the surface of the inner retina.  ...  An experimentally informed, two-dimensional hybrid partial differential equation-discrete model is derived to track the outward migration of individual astrocyte and endothelial tip cells in response to  ...  The authors gratefully acknowledge financial support from the BBSRC grant nos. BB/F002254/1 and BB/F002807/1.  ... 
doi:10.1098/rsif.2012.0067 pmid:22438490 pmcid:PMC3405746 fatcat:ohpsdvrnkfer7odw3n3ivv5bda

Mathematical Modeling of Oxygen Transport in theEye

Deepti Seth
2012 Applied Mathematics  
A simp le mathemat ical model for the steady state oxygen distribution in the eye has been developed.  ...  The results of the model may contribute when axial diffusion is impo rtant and when it can be neglected.  ...  In order to study the effect ofvarious parameters on the oxygen transport phenomena the model considers: ⅰ Oxygen transport in the retinal tissue ⅱ Oxygen transport within the retinal cap illary The model  ... 
doi:10.5923/j.am.20120204.01 fatcat:fgvezbrt4ba4bi3he5wln2yqby

Theoretical Analysis of Oxygen Consumption by Vascular Walls Exposed to Hemodynamic Stress in the Human Retinal Microvascular Network

Tatsuhisa TAKAHASHI, Akiyoshi OKADA, Tadashi SAITOH, Masanaga IKEGAMI, Hirotaka YANAGIDA
2010 Transactions of Japanese Society for Medical and Biological Engineering  
The rates at which endothelial and smooth muscle cells in vessel walls should consume oxygen during blood transport along the length of a microvascular network are highly controversial.  ...  We examined the arteriovenous distribution of oxygen consumption by a microvessel wall exposed to circumferential wall stress and fluid shear stress.  ...  , and oxygen content of blood and tissue, within the microvascular networks of the human retina.  ... 
doi:10.11239/jsmbe.48.482 fatcat:jmrb3c76nvcyxk67zacb5m3yye

The eye, the kidney and microcirculation

M. Blum, A. Saemann, G. Wolf
2010 Nephrology, Dialysis and Transplantation  
The mammalian retina has been found to possess an unusually high rate of glycolysis [7] and oxygen consumption [8] , with this activity fuelling the active transport processes that maintain the ionic  ...  Bayliss was the first to describe the myogenic constriction of arterioles when transmural pressure is elevated [2] .  ... 
doi:10.1093/ndt/gfq425 pmid:20628181 fatcat:l2dk6z7cy5gxhb7gaf7tjmsu5m

A Hybrid Discrete-Continuum Mathematical Model of Pattern Prediction in the Developing Retinal Vasculature

S. R. McDougall, M. G. Watson, A. H. Devlin, C. A. Mitchell, M. A. J. Chaplain
2012 Bulletin of Mathematical Biology  
Prior to birth, astrocytes migrate from the optic nerve over the surface of the inner retina in response to a chemotactic gradient of PDGF-A, formed at an earlier stage by migrating retinal ganglion cells  ...  The model of the functional vasculature is informed by a range of morphological and molecular data obtained over a period of several days, from 6 days prior to birth to approximately 8 days after birth  ...  Acknowledgements The authors gratefully acknowledge financial support from the BBSRC: Grant # BB/F002254/1 and BB/F002807/1.  ... 
doi:10.1007/s11538-012-9754-9 pmid:22829182 fatcat:zyp6meahefdejekkyigqeac4py

Effects of Changes in the Apparent Viscosity of Blood with Vessel Size on Retinal Microcirculation:Significance of the Fåhraeus-Lindqvist Effect

Tatsuhisa TAKAHASHI, Tadashi SAITOH, Yinlai JIANG, Shuoyu WANG, Akiyoshi OKADA, Hirotaka YANAGIDA
2011 Transactions of Japanese Society for Medical and Biological Engineering  
The purpose of this study was to quantitatively assess the influence of the Fåhraeus-Lindqvist effect on the microcirculation in the arteriovenous network of the human retina.  ...  The efficiency of blood transport to tissues in the microvascular bed, which was evaluated in terms of the inverse of the mechanical energy cost of the product of the driving pressure and blood flow, was  ...  This rheological property of blood in the macrocirculation with respect to the maximum transport of oxygen is evaluated in terms of the ratio of oxygen transport to blood viscosity [2] ; by definition  ... 
doi:10.11239/jsmbe.49.533 fatcat:yzmswpftdnh2feh74eqcj4uwze

Mathematical Modeling of Flow and Diffusion in the Lens of the Eye

Deependra Nigam, Rajesh Kumar Pal, Pradeep Kothiyal, Manoj Kumar Jadoun
2021 Journal of Scientific Research and Reports  
The model takes into account the transport of oxygen by diffusion and consumption of oxygen is assumed to follow the Michaelis- Menten's kinetics.  ...  The prime objective of the present study is to investigate the effect of model parameters: the Michaelis- Menten's kinetic constant and maximum rate of consumption on the partial pressure of oxygen in  ...  Aspect of European Journal of Pharmaceutical Science. 2008;32:175-182. 3. Avtar R, Tandon D. Modelling the Transmural Transport of Oxygen to the Retina."  ... 
doi:10.9734/jsrr/2021/v27i930433 fatcat:xadpgd25jvclzalkfrf5hfp53u

Microvascular oxygen tension in the rat mesentery

Aleksander S. Golub, Matthew C. Barker, Roland N. Pittman
2008 American Journal of Physiology. Heart and Circulatory Physiology  
Capillaries appear to be the primary site of oxygen delivery to the tissue in the mesenteric microcirculation.  ...  In light of the present results, previously reported data concerning oxygen consumption in the mesenteric microcirculation can be explained as artifacts of accumulated oxygen consumption due to the application  ...  modeling (36, 39, 40, 42) .  ... 
doi:10.1152/ajpheart.00861.2007 pmid:17951364 fatcat:cvwqjprk4bhshn5qdz7jml3g6i

The pathogenesis of diabetic retinopathy: old concepts and new questions

J Cai, M Boulton
2002 Eye (London. 1987)  
More recently, focus has been directed to the molecular basis of the disease process in diabetic retinopathy.  ...  factor) together with specific receptors and obligate components of the signal transduction pathway needed to support them.  ...  Acknowledgements The authors' research referred to in this review was funded by The Wellcome Trust and the British Diabetic Association.  ... 
doi:10.1038/sj.eye.6700133 pmid:12032713 fatcat:eytecfxzxbfc5bm5ir56jwrjc4

Ciliary blood flow and aqueous humor production

J.W. Kiel, M. Hollingsworth, R. Rao, M. Chen, H.A. Reitsamer
2011 Progress in retinal and eye research  
Aqueous humor production is a metabolically active process sustained by the delivery of oxygen and nutrients and removal of metabolic waste by the ciliary circulation.  ...  The results also show that the plateau portion of the relationship shifts up or down depending on the level of secretory stimulation or inhibition, and that oxygen is one critical factor provided by ciliary  ...  Sincere appreciation is expressed to Ms Alma Maldonado for her technical contributions and performance of many of the experiments.  ... 
doi:10.1016/j.preteyeres.2010.08.001 pmid:20801226 pmcid:PMC3010334 fatcat:dons4kwnhjarjezc7ob5k3b65e

Hyperspectral Computed Tomographic Imaging Spectroscopy of Vascular Oxygen Gradients in the Rabbit Retina In Vivo

Amir H. Kashani, Erlinda Kirkman, Gabriel Martin, Mark S. Humayun, Timothy W. Secomb
2011 PLoS ONE  
Application of this method to animal models of retinal vascular disease and clinical subjects will provide useful and novel information about retinal vascular disease and physiology.  ...  Up to 76 spectral measurements can be made in only a few milliseconds and used to quantify the oxygen saturation within the retinal vessels over a 10-15 degree field.  ...  In this paper, we implement the HCTIS to measure hemoglobin oxygen gradients within the microvasculature of the retina in vivo.  ... 
doi:10.1371/journal.pone.0024482 pmid:21931729 pmcid:PMC3172231 fatcat:jbl4e2ccxvgdle5uiifhkyn6me

Biofluid modeling of the coupled eye-brain system and insights into simulated microgravity conditions

Fabrizia Salerni, Rodolfo Repetto, Alon Harris, Peter Pinsky, Christophe Prud'homme, Marcela Szopos, Giovanna Guidoboni, Sakamuri V. Reddy
2019 PLoS ONE  
These findings indicate that the particular anatomical architecture of venous drainage in the retina may be one of the reasons why most of the SANS alterations are not observed in the retina but, rather  ...  To this end, we propose a reduced (0-dimensional) mathematical model of fluid flow in the eyes and brain, which is embedded into a simplified whole-body circulation model.  ...  Acknowledgments This work has been partially supported by the award NSF DMS-1853222/1853303, the Chair Gutenberg funds of the Cercle Gutenberg (France) and the Labex IRMIA and the IdEx Unistra (University  ... 
doi:10.1371/journal.pone.0216012 pmid:31412033 pmcid:PMC6693745 fatcat:4e6b5yjsj5g2jewbwjl4nfltkm
« Previous Showing results 1 — 15 out of 210 results