scholarly journals In vitro experiments of cerebral blood flow during aspiration thrombectomy: potential effects on cerebral perfusion pressure and collateral flow

2015 ◽  
Vol 8 (9) ◽  
pp. 969-972 ◽  
Author(s):  
Frank Lally ◽  
Mitra Soorani ◽  
Timothy Woo ◽  
Sanjeev Nayak ◽  
Changez Jadun ◽  
...  
Keyword(s):  
Direct Contact ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Collateral Flow ◽  
In Vitro Experiments ◽  
Aspiration Thrombectomy ◽  
Flow Solver ◽  
Catheter Tip

BackgroundMechanical thrombectomy with stent retriever devices is associated with significantly better outcomes than thrombolysis alone in the treatment of acute ischemic stroke. Thrombus aspiration achieves high patency rates, but clinical outcomes are variable. The aim of this study was to examine the effect of different suction conditions on perfusate flow during aspiration thrombectomy.MethodsA computational fluid dynamics model of an aspiration device within a patent and occluded blood vessel was used to simulate flow characteristics using fluid flow solver software. A physical particulate flow model of a patent vessel and a vessel occluded by thrombus was then used to visualize flow direction and measure flow rates with the aspiration catheter placed 1–10 mm proximal of the thrombus, and recorded on video.ResultsThe mathematical model predicted that, in a patent vessel, perfusate is drawn from upstream of the catheter tip while, in an occluded system, perfusate is drawn from the vessel proximal to the device tip with no traction on the occlusion distal of the tip. The in vitro experiments confirmed the predictions of this model. In the occluded vessel aspiration had no effect on the thrombus unless the tip of the catheter was in direct contact with the thrombus.ConclusionsThese experiments suggest that aspiration is only effective if the catheter tip is in direct contact with the thrombus. If the catheter tip is not in contact with the thrombus, aspirate is drawn from the vessels proximal of the occlusion. This could affect collateral flow in vivo.

scholarly journals Development of a gel dedicated to gel immersion endoscopy

2021 ◽  
Vol 09 (06) ◽  
pp. E918-E924
Author(s):  
Tomonori Yano ◽  
Atsushi Ohata ◽  
Yuji Hiraki ◽  
Makoto Tanaka ◽  
Satoshi Shinozaki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Porcine Model ◽  
Ex Vivo ◽  
In Vitro Experiments ◽  
Efficacy And Safety ◽  
Coagulative Necrosis ◽  
Novel Technique ◽  
In Vivo Experiments

Abstract Backgrounds and study aims Gel immersion endoscopy is a novel technique to secure the visual field during endoscopy. The aim of this study was to develop a dedicated gel for this technique. Methods To identify appropriate viscoelasticity and electrical conductivity, various gels were examined. Based on these results, the dedicated gel “OPF-203” was developed. Efficacy and safety of OPF-203 were evaluated in a porcine model. Results  In vitro experiments showed that a viscosity of 230 to 1900 mPa·s, loss tangent (tanδ) ≤ 0.6, and hardness of 240 to 540 N/cm2 were suitable. Ex vivo experiments showed electrical conductivity ≤ 220 μS/cm is appropriate. In vivo experiments using gastrointestinal bleeding showed that OPF-203 provided clear visualization compared to water. After electrocoagulation of gastric mucosa in OPF-203, severe coagulative necrosis was not observed in the muscularis but limited to the mucosa. Conclusions OPF-203 is useful for gel immersion endoscopy.

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.

Anticancer effect of arsenic trioxide on cholangiocarcinoma: in vitro experiments and in vivo xenograft mouse model

2013 ◽  
Vol 14 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Eun-Young Kim ◽  
Sang Soo Lee ◽  
Ji Hoon Shin ◽  
Soo Hyun Kim ◽  
Dong-Ho Shin ◽  
...  
Keyword(s):  
Mouse Model ◽  
Arsenic Trioxide ◽  
In Vitro Experiments ◽  
Anticancer Effect ◽  
Xenograft Mouse Model

scholarly journals Reversible neutralization by congo red of the anthracidal power of serum

1937 ◽  
Vol 37 (3) ◽  
pp. 471-473 ◽  
Author(s):  
J. Gordon ◽  
N. Wood
Keyword(s):  
Guinea Pig ◽  
Congo Red ◽  
Inhibitory Action ◽  
Protein Solutions ◽  
Haemolytic Activity ◽  
In Vitro Experiments ◽  
Serum Complement ◽  
Destructive Effect

In earlier papers (Gordon, 1930) it was shown that congo red has an inactivating effect on serum complement, both haemolytic and bactericidal, and that this effect can be reversed by treating the serum and congo red mixture with charcoal, the charcoal removing the congo red and leaving the complement active again. A similar reversal of inactivation is obtained by using instead of the charcoal, heated serum (55° C. for 30 min.) or protein solutions. Later (Gordon, 1931), it was shown that congo red had an inactivating effect on the haemolysins of Streptococcus haemolyticus and B. welchii. The reversibility of this effect was not so easy to demonstrate as with complement. Charcoal had a destructive effect on the haemolysins and so could not be used. It was found, however, that when the concentration of congo red was just sufficient to neutralize the streptococcal haemolysin, the addition of cuprammonium artificial silk adsorbed the congo red and liberated the haemolysin. In the case of B. welchii this method of reversal was not suitable, as the artificial silk had a destructive effect on the haemolysin. Instead, reversibility was demonstrated by adding ox serum to the mixture of congo red and haemolysin. This brought about a redistribution of the congo red between the ox serum and the haemolysin and if the amount of congo red used had been only just sufficient to neutralize the haemolysin of B. welchii, then the haemolytic activity could again be demonstrated. Gordon and Robson (1933) showed that congo red interfered with the anaphylactic reaction tested both in vivo and in vitro, the guinea-pig uterus being used in the in vitro experiments, in which the inhibitory action of the dye was shown to be reversible. It was suggested that the congo red interfered with the entrance of antigen into the cell.

scholarly journals Interaction of integrins alpha 3 beta 1 and alpha 2 beta 1: potential role in keratinocyte intercellular adhesion.

1993 ◽  
Vol 120 (2) ◽  
pp. 523-535 ◽  
Author(s):  
B E Symington ◽  
Y Takada ◽  
W G Carter
Keyword(s):  
Potential Role ◽  
Intercellular Adhesion ◽  
Epidermal Cells ◽  
Intercellular Contact ◽  
In Vitro Experiments ◽  
Selective Binding ◽  
Contact Sites ◽  
Do So

The colocalization of integrins alpha 2 beta 1 and alpha 3 beta 1 at intercellular contact sites of keratinocytes in culture and in epidermis suggests that these integrins may mediate intercellular adhesion (ICA). P1B5, an anti-alpha 3 beta 1 mAb previously reported to inhibit keratinocyte adhesion to epiligrin, was also found to induce ICA. Evidence that P1B5-induced ICA was mediated by alpha 2 beta 1 and alpha 3 beta 1 was obtained using both ICA assays and assays with purified, mAb-immobilized integrins. Selective binding of alpha 2 beta 1-coated beads to epidermal cells or plate-bound alpha 3 beta 1 was observed. This binding was inhibited by mAbs to integrin alpha 3, alpha 2, or beta 1 subunits and could be stimulated by P1B5. We also demonstrate a selective and inhibitable interaction between affinity-purified integrins alpha 2 beta 1 and alpha 3 beta 1. Finally, we show that expression of alpha 2 beta 1 by CHO fibroblasts results in the acquisition of collagen and alpha 3 beta 1 binding. Binding to both of these ligands is inhibited by P1H5, an anti-alpha 2 beta 1 specific mAb. Results of these in vitro experiments suggest that integrins alpha 2 beta 1 and alpha 3 beta 1 can interact and may do so to mediate ICA in vivo. Thus, alpha 3 beta 1 mediates keratinocyte adhesion to epiligrin and plays a second role in ICA via alpha 2 beta 1.

scholarly journals Cilengitide Inhibits Neovascularization in a Rabbit Abdominal Aortic Plaque Model by Impairing the VEGF Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Fawang Zhu ◽  
Shuai Yuan ◽  
Jing Li ◽  
Yun Mou ◽  
Zhiqiang Hu ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Tube Formation ◽  
Control Group ◽  
In Vitro Experiments ◽  
Aortic Plaque ◽  
Abdominal Aortic ◽  
Aortic Plaques ◽  
Different Doses

Background. Cilengitide is a selective αvβ3 and αvβ5 integrin inhibitor. We sought to investigate the effect of cilengitide on the neovascularization of abdominal aortic plaques in rabbits and explore its underlying antiangiogenic mechanism on human umbilical vein endothelial cells (HUVECs). Materials and Methods. For the in vivo experiment, the abdominal aortic plaque model of rabbits was established and injected with different doses of cilengitide or saline for 14 consecutive days. Conventional ultrasound (CUS) and contrast-enhanced ultrasound (CEUS) were applied to measure the vascular structure and blood flow parameters. CD31 immunofluorescence staining was performed for examining neovascularization. Relative expressions of vascular endothelial growth factor (VEGF) and integrin of the plaque were determined. For in vitro experiments, HUVECs were tested for proliferation, migration, apoptosis, and tube formation in the presence of different doses of cilengitide. Relative expressions of VEGF, integrin, and Ras/ERK/AKT signaling pathways were determined for the exploration of underlying mechanism. Results. CEUS showed modestly increased size and eccentricity index (EI) of plaques in the control group. Different degrees of reduced size and EI of plaques were observed in two cilengitide treatment groups. The expressions of VEGF and integrin in the plaque were inhibited after 14 days of cilengitide treatment. The neovascularization and apoptosis of the abdominal aorta were also significantly alleviated by cilengitide treatment. For in vitro experiments, cilengitide treatment was found to inhibit the proliferation, migration, and tube formation of HUVECs. However, cilengitide did not induce the apoptosis of HUVECs. A higher dose of cilengitide inhibited the mRNA expression of VEGF-A, β3, and β5, but not αV. Lastly, cilengitide treatment significantly inhibited the Ras/ERK/AKT pathway in the HUVECs. Conclusions. This study showed that cilengitide effectively inhibited the growth of plaque size by inhibiting the angiogenesis of the abdominal aortic plaques and blocking the VEGF-mediated angiogenic effect on HUVECs.

scholarly journals Methane alleviates sepsis-induced injury by inhibiting pyroptosis and apoptosis: in vivo and in vitro experiments

Aging ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 1226-1239 ◽  
Author(s):  
Zeyu Li ◽  
Yifan Jia ◽  
Yang Feng ◽  
Ruixia Cui ◽  
Runchen Miao ◽  
...  
Keyword(s):  
In Vitro Experiments

scholarly journals Shear-induced endothelial cell-cell junction inclination

2010 ◽  
Vol 299 (3) ◽  
pp. C621-C629 ◽  
Author(s):  
Benoît Melchior ◽  
John A. Frangos
Keyword(s):  
Endothelial Cell ◽  
Flow Direction ◽  
Cell Junction ◽  
Structural Basis ◽  
Retrograde Flow ◽  
Arterial Circulation ◽  
Mouse Aorta ◽  
Cell Cell

Atheroprone regions of the arterial circulation are characterized by time-varying, reversing, and oscillatory wall shear stress. Several in vivo and in vitro studies have demonstrated that flow reversal (retrograde flow) is atherogenic and proinflammatory. The molecular and structural basis for the sensitivity of the endothelium to flow direction, however, has yet to be determined. It has been hypothesized that the ability to sense flow direction is dependent on the direction of inclination of the interendothelial junction. Immunostaining of the mouse aorta revealed an inclination of the cell-cell junction by 13° in direction of flow in the descending aorta where flow is unidirectional. In contrast, polygonal cells of the inner curvature where flow is disturbed did not have any preferential inclination. Using a membrane specific dye, the angle of inclination of the junction was dynamically monitored using live cell confocal microscopy in confluent human endothelial cell monolayers. Upon application of shear the junctions began inclining within minutes to a final angle of 10° in direction of flow. Retrograde flow led to a reversal of junctional inclination. Flow-induced junctional inclination was shown to be independent of the cytoskeleton or glycocalyx. Additionally, within seconds, retrograde flow led to significantly higher intracellular calcium responses than orthograde flow. Together, these results show for the first time that the endothelial intercellular junction inclination is dynamically responsive to flow direction and confers the ability to endothelial cells to rapidly sense and adapt to flow direction.

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