scholarly journals An isolated tumor perfusion model in mice

2012 ◽  
Vol 7 (4) ◽  
pp. 749-755 ◽  
Author(s):  
Annique M M J Duyverman ◽  
Mitsutomo Kohno ◽  
Sylvie Roberge ◽  
Dai Fukumura ◽  
Dan G Duda ◽  
...  
Keyword(s):  
Tumor Perfusion ◽  
Perfusion Model

Prostanoid Release from Ex Vivo Perfused Canine Arteries and Veins: Effects of Prolonged Perfusion, Intermittent Perfusion, as well as Exposure to Exogenous Arachidonic Acid, Thrombin and Bradykinin

1989 ◽  
Vol 62 (03) ◽  
pp. 1034-1039 ◽  
Author(s):  
Jan S Brunkwall ◽  
James C Stanley ◽  
Timothy F Kresowik ◽  
Linda M Graham ◽  
William E Burkel ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Ex Vivo ◽  
Fold Increase ◽  
Ex Vivo Perfusion ◽  
Cyclooxygenase Activity ◽  
Perfusion Model ◽  
Prostanoid Production ◽  
Slow Decline ◽  
Arteries And Veins ◽  
Nonpulsatile Flow

SummaryRegulation of prostanoid release from ex vivo perfused vessel segments is not fully understood. A series of perfusion experiments were performed with canine arteries and veins to define certain regulatory phenomena. Arteries were perfused with pulsatile flow of 90 ml/min at a pressure of 100 mmHg, and veins with nonpulsatile flow of 90 ml/min at a pressure of 7 mmHg. Segments were perfused with Hanks' balanced salt solution for five 15-min periods with the perfusate exchanged after each study period. With onset of perfusion, there was an initial burst of prostacyclin release to 127 ± 40 pg/mm2, declining to 32 ± 10 pg/mm2 after 60 minutes (p <0.005). If perfusion continued for 5.5 hours, there was a stable release period between 1 and 3 hours, followed by a very slow decline. At that time addition of arachidonic acid (AA) increased prostacyclin release six-fold (p <0.01). Vessels perfused for 1 hour and then rested for another hour, responded to reperfusion at the second onset of flow with a two-fold increase in prostacyclin release (p <0.01). Vessels perfused with thrombin, bradykinin or A A (either added to each perfusate or only to the last perfusate) exhibited greater prostacyclin release than did control segments. Release of thromboxane steadily declined with time in all parts of the study, and only increased with the addition of A A to the perfusate. These data indicate that vessel segments subjected to ex vivo perfusion do not maximally utilize enzyme systems responsible for prostanoid production, and after 1 hour perfusion have not depleted their phospholipids, and maintain functioning levels of phospholipase and cyclooxygenase activity. This perfusion model allows for the study of prostacyclin and thromboxane release from arteries and veins and their response to various drugs and other stimuli.

scholarly journals 474: Placenta transfer of sildenafil citrate in the ex-vivo human cotyledon perfusion model

2017 ◽  
Vol 216 (1) ◽  
pp. S280 ◽  
Author(s):  
FRANCESCA M. RUSSO ◽  
SIGRID CONINGS ◽  
PIETER ANNAERT ◽  
TIM VAN MIEGHEM ◽  
JAAN TOELEN ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Sildenafil Citrate ◽  
Perfusion Model

scholarly journals Attenuated Microcirculation in Small Metastatic Tumors in Murine Liver

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 703
Author(s):  
Arturas Ziemys ◽  
Vladimir Simic ◽  
Miljan Milosevic ◽  
Milos Kojic ◽  
Yan Ting Liu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Liver Metastases ◽  
Clinical Success ◽  
Metastatic Cancer ◽  
In Vivo Studies ◽  
Central Vein ◽  
Tumor Perfusion ◽  
Metastatic Tumors ◽  
Liver Lobule

Metastatic cancer disease is the major cause of death in cancer patients. Because those small secondary tumors are clinically hardly detectable in their early stages, little is known about drug biodistribution and permeation into those metastatic tumors potentially contributing to insufficient clinical success against metastatic disease. Our recent studies indicated that breast cancer liver metastases may have compromised perfusion of intratumoral capillaries hindering the delivery of therapeutics for yet unknown reasons. To understand the microcirculation of small liver metastases, we have utilized computational simulations to study perfusion and oxygen concentration fields in and around the metastases smaller than 700 µm in size at the locations of portal vessels, central vein, and liver lobule acinus. Despite tumor vascularization, the results show that blood flow in those tumors can be substantially reduced indicating the presence of inadequate blood pressure gradients across tumors. A low blood pressure may contribute to the collapsed intratumoral capillary lumen limiting tumor perfusion that phenomenologically corroborates with our previously published in vivo studies. Tumors that are smaller than the liver lobule size and originating at different lobule locations may possess a different microcirculation environment and tumor perfusion. The acinus and portal vessel locations in the lobule were found to be the most beneficial to tumor growth based on tumor access to blood flow and intratumoral oxygen. These findings suggest that microcirculation states of small metastatic tumors can potentially contribute to physiological barriers preventing efficient delivery of therapeutic substances into small tumors.

Dynamic Contrast-Enhanced MRI and Fractal Characteristics of Percolation Clusters in Two-Dimensional Tumor Blood Perfusion

1999 ◽  
Vol 121 (5) ◽  
pp. 480-486 ◽  
Author(s):  
O. I. Craciunescu ◽  
S. K. Das ◽  
S. T. Clegg
Keyword(s):  
Tumor Tissue ◽  
Blood Perfusion ◽  
Percolation Cluster ◽  
Three Dimensions ◽  
Invasion Percolation ◽  
Two Dimensional ◽  
Tumor Perfusion ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Fractal Characteristics

Dynamic contrast-enhanced magnetic resonance imaging (DE-MRI) of the tumor blood pool is used to study tumor tissue perfusion. The results are then analyzed using percolation models. Percolation cluster geometry is depicted using the wash-in component of MRI contrast signal intensity. Fractal characteristics are determined for each two-dimensional cluster. The invasion percolation model is used to describe the evolution of the tumor perfusion front. Although tumor perfusion can be depicted rigorously only in three dimensions, two-dimensional cases are used to validate the methodology. It is concluded that the blood perfusion in a two-dimensional tumor vessel network has a fractal structure and that the evolution of the perfusion front can be characterized using invasion percolation. For all the cases studied, the front starts to grow from the periphery of the tumor (where the feeding vessel was assumed to lie) and continues to grow toward the center of the tumor, accounting for the well-documented perfused periphery and necrotic core of the tumor tissue.

The Suitability of an in Situ Perfusion Model for Permeability Determinations:  Utility for BCS Class I Biowaiver Requests

2006 ◽  
Vol 3 (6) ◽  
pp. 686-694 ◽  
Author(s):  
Jae-Seung Kim ◽  
Stefanie Mitchell ◽  
Paul Kijek ◽  
Yasuhiro Tsume ◽  
John Hilfinger ◽  
...  
Keyword(s):  
Class I ◽  
In Situ Perfusion ◽  
Perfusion Model

Placental transfer of rosiglitazone in the ex vivo human perfusion model

2006 ◽  
Vol 195 (6) ◽  
pp. 1715-1719 ◽  
Author(s):  
Heather J. Holmes ◽  
Brian M. Casey ◽  
Roger E. Bawdon
Keyword(s):  
Placental Transfer ◽  
Ex Vivo ◽  
Perfusion Model
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