scholarly journals Methods and Limits for Micro Scale Blood Vessel Flow Imaging in Scattering Media by Optical Feedback Interferometry: Application to Human Skin

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1300 ◽  
Author(s):  
Adam Quotb ◽  
Reza Atashkhooei ◽  
Simone Magaletti ◽  
Francis Jayat ◽  
Clement Tronche ◽  
...  
Keyword(s):  
Blood Flow ◽  
Human Skin ◽  
Network Architecture ◽  
Health Management ◽  
Optical Feedback ◽  
Flow Imaging ◽  
Scattering Media ◽  
In Vivo Test

At the micrometric scale, vessels or skin capillaries network architecture can provide useful information for human health management. In this paper, from simulation to in vitro, we investigate some limits and interests of optical feedback interferometry (OFI) for blood flow imaging of skin vascularization. In order to analyze the tissue scattering effect on OFI performances, a series of skin-tissue simulating optical phantoms have been designed, fabricated and characterized. The horizontal (2D) and vertical (depth penetration) sensing resolution of the OFI sensor have been estimated. The experimental results that we present on this study are showing a very good accordance with theoretical models. In the case of a skin phantom of 0.5 mm depth with a scattering coefficient from 0 to 10.8 mm−1, the presented OFI system is able to distinguish a pair of micro fluidic channels (100 µm × 100 µm) spaced by 10 µm. Eventually, an in vivo test on human skin is presented and, for the first time using an OFI sensor, a 2D blood flow image of a vein located just beneath the skin is computed.

PGD2 is an intermediate in agonist-stimulated nitric oxide release in rabbit skin microcirculation

1994 ◽  
Vol 266 (5) ◽  
pp. H1846-H1853
Author(s):  
J. B. Warren ◽  
R. K. Loi ◽  
A. J. Wilson
Keyword(s):  
Blood Flow ◽  
Arachidonic Acid ◽  
Skin Blood Flow ◽  
Prostaglandin D2 ◽  
Skin Microcirculation ◽  
Rabbit Skin ◽  
In Vivo Test ◽  
Prostaglandin Release

We investigated the role of endogenous prostaglandins and NO in the blood flow response of skin microcirculation in vivo. Test agents were injected intradermally in anesthetized rabbits and changes in skin blood flow measured with a laser-Doppler flow probe. Skin blood flow increased 75% at 7.33, 6.77, 11.63, 10.30, 10.55, 8.20, and < 7 -log mol/site with acetylcholine, ATP, bradykinin, prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), NO gas in solution, and nitroprusside respectively. Co-injection of indomethacin (3 x 10(-9) mol/site) or NG-nitro-L-arginine methyl ester (L-NAME; 10(-7) mol/site) with either acetylcholine or bradykinin abolished the effects. This suggests a link between NO and prostaglandin release. Arachidonic acid increased blood flow, which was inhibited by indomethacin, L-NAME, or the PGD2-receptor antagonist BW-A868C. Blood flow responses to either intradermal acetyl-choline or bradykinin, but not to NO in solution, were abolished by co-injection with BW-A868C. PGD2-mediated vasodilation was abolished by L-NAME or BW-A868C, but not by indomethacin. There was no evidence of a link between NO and prostaglandin release in precontracted rabbit aortic rings in vitro. The results suggest that, in the microcirculation of rabbit skin, acetylcholine- and bradykinin-mediated vasodilation involve the arachidonic acid-PGD2-NO pathway.

Effect of caffeine on theophyliine on cerebral blood flow response to brain activation: In vitro and in vivo studies

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Activation ◽  
In Vivo Studies ◽  
Blood Flow Response ◽  
Flow Response

Defibrotide Inhibits Platelet Activation by Cathepsin G Released From Stimulated Polymorphonuclear Leukocytes

1992 ◽  
Vol 67 (06) ◽  
pp. 660-664 ◽  
Author(s):  
Virgilio Evangelista ◽  
Paola Piccardoni ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti
Keyword(s):  
Platelet Activation ◽  
Polymorphonuclear Leukocytes ◽  
Direct Interaction ◽  
Cathepsin G ◽  
In Vivo Test ◽  
Cell Functions ◽  
Test Models ◽  
Antithrombotic Effects

SummaryDefibrotide is a polydeoxyribonucleotide with antithrombotic effects in experimental animal models. Most of the actions of this drug have been observed in in vivo test models but no effects have been reported in in vitro systems. In this paper we demonstrate that defibrotide interferes with polymorphonuclear leukocyte-induced human platelet activation in vitro. This effect was not related to any direct interaction with polymorphonuclear leukocytes or platelets, but was due to the inhibition of cathepsin G, the main biochemical mediator of this cell-cell cooperation. Since cathepsin G not only induces platelet activation but also affects some endothelial cell functions, the anticathepsin G activity of defibrotide could help to explain the antithrombotic effect of this drug.

Comparative Evaluation of In Vitro and In Vivo Assays for the Detection of Avian Infectious Bronchitis Virus as a Contaminant of Live Poultry Vaccines

1998 ◽  
Vol 26 (5) ◽  
pp. 629-634
Author(s):  
Emiliana Falcone ◽  
Edoardo Vignolo ◽  
Livia Di Trani ◽  
Simona Puzelli ◽  
Maria Tollis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Serological Response ◽  
Avian Infectious Bronchitis Virus ◽  
Animal Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
In Vivo Test ◽  
Infectious Bronchitis

A reverse transcriptase polymerase chain reaction (RT-PCR) assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

Abstract WP498: Impaired Pericyte Constriction and Cerebral Blood Flow Autoregulationin Diabetes

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Yedan Liu ◽  
Shaoxun Wang ◽  
Ya Guo ◽  
Huawei Zhang ◽  
Richard Roman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ex Vivo ◽  
Mitochondrial Dynamics ◽  
Vascular Cognitive Impairment ◽  
Treated Group ◽  
Diabetic Rats ◽  
Cerebrovascular Function

Diabetes is the primary pathological factor attributed to Alzheimer’s disease and vascular cognitive impairment. Previous studies demonstrated that hyperglycemia promoted oxidative stress in the cerebral vasculature. Cerebrovascular pericytes contribute to maintaining blood-brain barrier (BBB) integrity and regulating cerebral blood flow (CBF). However, whether hyperglycemia diminishes the contractile capability of pericytes, impairs CBF autoregulation and increases BBB permeability are unclear. In the present study, we examined the role of pericytes in cerebrovascular function and cognition in diabetes using cell culture in vitro , isolated penetrating arterioles ex vivo and CBF autoregulation in vivo . Reactive oxygen species were elevated in high glucose (HG, 30 mM) treated vs. normal glucose (NG, 5.5 mM) treated pericytes. Further, mitochondrial superoxide production was increased in HG-treated vs. NG-treated group (13.24 ± 1.01 arbitrary unit (a.u.)/30min vs. 6.98 ± 0.36 a.u./30min). Mitochondrial respiration decreased in HG-treated vs. NG-treated pericytes (3718 ± 185.9 pmol/min/mg, n=10 vs. 4742 ± 284.5 pmol/min/mg, n=10) as measured by a Seahorse XFe24 analyzer. HG-treated pericytes displayed fragmented mitochondria in association with increased fission protein (DRP1) and decreased fusion protein (OPA1) expression. HG-treated pericytes displayed lower contractile capability than NG-treated cells (20.23 ± 7.15% vs. 29.46 ± 9.41%). The myogenic response was impaired in penetrating arterioles isolated from diabetic rats in comparison with non-diabetic rats. Autoregulation of CBF measured by a laser Doppler flowmeter was impaired in diabetic rats compared with non-diabetic rats. Diabetic rats exhibited greater BBB leakage than control rats. The cognitive function was examined using an eight-arm water maze. Diabetic rats took longer time to escape than the non-diabetic rats indicating learning and memory deficits. In conclusion, hyperglycemia induces pericyte dysfunction by altering mitochondrial dynamics and diminishing contractile capability, which promotes BBB leakage, decreases CBF autoregulation and contributes to diabetes-related dementia.

scholarly journals Effects of aging and exercise training on spinotrapezius muscle microvascular Po2 dynamics and vasomotor control

2011 ◽  
Vol 110 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Danielle J. McCullough ◽  
Robert T. Davis ◽  
James M. Dominguez ◽  
John N. Stabley ◽  
Christian S. Bruells ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Training ◽  
Sodium Nitroprusside ◽  
Vascular Function ◽  
Treadmill Running ◽  
Aged Rats ◽  
Phosphorescence Quenching

With advancing age, there is a reduction in exercise tolerance, resulting, in part, from a perturbed ability to match O2 delivery to uptake within skeletal muscle. In the spinotrapezius muscle (which is not recruited during incline treadmill running) of aged rats, we tested the hypotheses that exercise training will 1) improve the matching of O2 delivery to O2 uptake, evidenced through improved microvascular Po2 (PmO2), at rest and throughout the contractions transient; and 2) enhance endothelium-dependent vasodilation in first-order arterioles. Young (Y, ∼6 mo) and aged (O, >24 mo) Fischer 344 rats were assigned to control sedentary (YSED; n = 16, and OSED; n = 15) or exercise-trained (YET; n = 14, and OET; n = 13) groups. Spinotrapezius blood flow (via radiolabeled microspheres) was measured at rest and during exercise. Phosphorescence quenching was used to quantify PmO2 in vivo at rest and across the rest-to-twitch contraction (1 Hz, 5 min) transition in the spinotrapezius muscle. In a follow-up study, vasomotor responses to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) stimuli were investigated in vitro. Blood flow to the spinotrapezius did not increase above resting values during exercise in either young or aged groups. Exercise training increased the precontraction baseline PmO2 (OET 37.5 ± 3.9 vs. OSED 24.7 ± 3.6 Torr, P < 0.05); the end-contracting PmO2 and the time-delay before PmO2 fell in the aged group but did not affect these values in the young. Exercise training improved maximal vasodilation in aged rats to acetylcholine (OET 62 ± 16 vs. OSED 27 ± 16%) and to sodium nitroprusside in both young and aged rats. Endurance training of aged rats enhances the PmO2 in a nonrecruited skeletal muscle and is associated with improved vascular smooth muscle function. These data support the notion that improvements in vascular function with exercise training are not isolated to the recruited muscle.

Blood flow to brown fat in lean and obese adrenalectomized Zucker rats

1986 ◽  
Vol 251 (5) ◽  
pp. R851-R858
Author(s):  
S. J. Wickler ◽  
B. A. Horwitz ◽  
J. S. Stern
Keyword(s):  
Blood Flow ◽  
Weight Gain ◽  
Brown Fat ◽  
Zucker Rats ◽  
Zucker Rat ◽  
Nonshivering Thermogenesis ◽  
Brown Adipose ◽  
Obese Rats

The Zucker obese rat is characterized by decreased capacity for diet-induced and for nonshivering thermogenesis. This decrease is due, in large part, to reduced thermogenesis in depots of brown adipose tissue, a major source of heat production in rats. Adrenalectomy retards the weight gain observed in the obese rats and also normalizes brown fat guanosine 5'-diphosphate (GDP) binding, an in vitro measure of brown fat thermogenic capacity. This study examined the effect of adrenalectomy on brown fat blood flow, an in vivo measure of the tissue's function, and on norepinephrine-induced O2 consumption (NST) of 11-wk-old obese (fa/fa) and lean (Fa/?) rats. Adrenalectomy had little effect on weight gain, NST, or norepinephrine-stimulated blood flow to brown fat in lean rats. However, adrenalectomy produced profound changes in the obese animals, preventing the weight gain normally occurring in the obese rats and normalizing both NST capacity and norepinephrine-stimulated blood flow to brown fat. These findings provide further support for the importance of brown fat thermogenesis and glucocorticoids in modulating the obesity of the Zucker rat.

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