Shear-induced platelet adherence and activation in an in-vitro dynamic multiwell-plate system

2019 ◽  
Vol 71 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Markus Reinthaler ◽  
Johan Bäckemo Johansson ◽  
Steffen Braune ◽  
Haitham Saleh Ali Al-Hindwan ◽  
Andreas Lendlein ◽  
...  
Keyword(s):  
Platelet Adherence ◽  
Plate System

Interactions Between Blood Platelets and Vascular Endothelium in vitro Studies

1979 ◽  
Author(s):  
M.A. Gimbrone ◽  
K.D. Curwen ◽  
R. I. Handin
Keyword(s):  
Platelet Aggregation ◽  
Vascular Endothelium ◽  
Potent Inhibitor ◽  
Platelet Reactivity ◽  
Blood Platelets ◽  
Primary Cultures ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Platelet Adherence

Endothelial cells (EC) can actively influence the hemostatic response at sites of vascular injury through multiple mechanisms. For example, EC can degrade adenosine diphosphate, release plasminogen activator, and synthesize prostacyclin (PGI2), a potent inhibitor of platelet aggregation. We have examined whether PGI2 also might account for the normal lack of platelet adherence to the uninjured EC surface. In a monolayer adherence assay, radiolabeled human platelets in citrated plasma showed minimal interaction with primary cultures of human EC (<1 platelet adhering per cell). Platelets from aspirin-treated and untreated donors behaved similarly. However, aspirin pretreatment of EC consistently resulted in ~2-fold increases in platelet adherence which could be completely abolished by exogenous PGI2 (0.5–1.0 μg/ml). SV40-transformed human EC (SVHEC), which are deficient in PGI2 production compared to primary EC, showed 10-30 times more platelet adherence. Exogenous PGI2 produced a dose - related (.001-1.0 μg/ml) decrease in platelet adherence to SVHEC but did not result in the basal levels observed with normal EC monolayers. These data suggest that : 1) In addition to its effects on platelet aggregation, PGI2 can influence platelet endothelial cell interactions; 2) The increased platelet reactivity of transformed EC is associated with, but not completely attributable, to decreased PGI2 production; and 3) Factors other than PGI2 may play a role in the thromboresistance of normal vascular endothelium.

Quantitation of Platelet Adherence to Rabbit Aortae and Platelet Survival After two Injuries with a Balloon Catheter

1979 ◽  
Author(s):  
R.L. Kinlough-Rathbone ◽  
H.M. Groves ◽  
S. Maric ◽  
M.A. Packham ◽  
J.F. Mustard
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Balloon Catheter ◽  
Rabbit Aorta ◽  
Platelet Adherence ◽  
Platelet Survival ◽  
Single Balloon

Following a single balloon catheter injury to a rabbit aorta (INJ 1) a monolayer of platelets covers the subendothelium within 10 min, the surface becomes relatively non-reactive to further platelet accumulation and platelet survival is not altered. We have now studied whether a second similar injury (INJ 2) of the non-reactive, smooth muscle cell-rich neointima 7 days after INJ 1 makes the surface of the neointima reactive to platelets or alters platelet survival. 51Cr-platelet adherence to the neointima of aortae subjected to INJ 2 in vitro 7 days after an initial in vivo injury was not significantly different from the adherence following a single in vitro injury (16,600 ± 3100 platelets/mm2 and 27,600 ± 4000 respectively, ρ > 0.2). In vivo adherence of 51Cr-platelets to the surface of rabbit aortae was similar following INJ 1 (0.084 ± 0.009% of the circulate, platelets) and INJ 2 (0.130 ± 0.03%, p > 0.2). Platelet survival after injury to the neointima was not significantly different in animals with an undamaged aortic endothelium (74.6 ± 5.9 hr and 80.2 ± 4.3 hr respectively, ρ > 0.5). Thus, a second injury involving the smooth’ muscle cell-rich neointima that forms after removal of the endothelium with a balloon catheter does not cause more platelets to accumulate than the initial injury, nor shorten platelet survival.

Detection of Proximal Caries in vitro Using Standard and Task-Specific Enhanced Images from a Storage Phosphor Plate System

2007 ◽  
Vol 41 (3) ◽  
pp. 231-234 ◽  
Author(s):  
G. Li ◽  
G.C.H. Sanderink ◽  
W.E.R. Berkhout ◽  
K. Syriopoulos ◽  
P.F. van der Stelt
Keyword(s):  
Proximal Caries ◽  
Storage Phosphor ◽  
Phosphor Plate ◽  
Plate System ◽  
And Task

Quantitation of Platelet Adherence to Rabbit Aortae and Platelet Survival After Two Injuries With a Balloon Catheter

1979 ◽  
Author(s):  
R Kinlough-Rathbone ◽  
H Groves ◽  
S Maric ◽  
M Packham ◽  
J Mustard
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Balloon Catheter ◽  
Rabbit Aorta ◽  
Platelet Adherence ◽  
Platelet Survival ◽  
Single Balloon

Following a single balloon catheter injury to a rabbit aorta (INJ 1) a monolayer of platelets covers the subendothelium within 10 min, the surface becomes relatively nonreactive to further platelet accumulation and platelet survival is not altered. We have now studied whether a second similar injury (INJ 2) of the non-reactive, smooth muscle cell-rich neointima 7 days after INJ 1 makes the surface of the neointima reactive to platelets or alters platelet survival. 51Cr-platelet adherence to the neointima of aortae subjected to INJ 2 in vitro 7 days after an initial in vivo injury was not significantly different from the adherence following a single in vitro injury (16,600 ± 3100 platelets/mm2 and 27,600 ± 4000 respectively, p > 0.2). In vivo adherence of 51Cr-platelets to the surface of rabbit aortae was similar following INJ 1 (0.084 ± 0.009% of the circulating platelets) and INJ 2 (0.130 ± 0.03%, p > 0.2). Platelet survival after injury to the neointima was not significantly different in animals with an undamaged aortic endothelium (74.6 ±5.9 hr and 80.2 ± 4.3 hr respectively, p > 0.5). Thus, a second injury involving the smooth muscle cell-rich neointima that forms after removal of the endothelium with a balloon catheter does not cause more platelets to accumulate than the initial injury, nor shorten platelet survival.

scholarly journals Increased red blood cell deformability due to isoxsuprine administration decreases platelet adherence in a perfusion chamber: a double-blind cross-over study in patients with intermittent claudication

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1474-1481
Author(s):  
PA Aarts ◽  
JD Banga ◽  
HC van Houwelingen ◽  
RM Heethaar ◽  
JJ Sixma
Keyword(s):  
Platelet Count ◽  
Shear Rate ◽  
Vessel Wall ◽  
Double Blind ◽  
Platelet Adherence ◽  
Perfusion Chamber ◽  
Platelet Transport ◽  
Rbc Deformability

Platelet transport towards the vessel wall is influenced by the hematocrit, red blood cell (RBC) size, and shape. Recent in vitro studies have indicated that RBC deformability may also influence platelet transport. The observation that isoxsuprine, a known vasodilating drug, caused increased RBC deformability in vitro and decreased platelet transport in vitro prompted us to study the effects of this drug in vivo. The study was performed in a double-blind cross- over study of isoxsuprine v placebo in ten patients with peripheral arterial insufficiency. RBC deformability was estimated from viscosity measurements using the blood viscosity equation of Dintenfass and expressed as T value. Platelet transport was studied in an annular perfusion chamber according to Baumgartner. Human umbilical arteries were used as blood vessels. Perfusion studies were performed with whole blood or with RBCs of the patients mixed with normal platelets and plasma at a standardized hematocrit and platelet count. An increase in RBC deformability concomitant with a decrease in platelet adherence was observed in patients on isoxsuprine with a drop in T value of approximately 0.06 (from 0.91 toward 0.86), and a concomitant decrease in platelet adherence of 20% to 40%. These observations differed significantly from the results in the placebo group and showed a significant group-period interaction at the cross-over of medication (analysis of variance). The effects on platelet adherence were observed at high vessel wall shear rate (1,800 s-1) with perfusates consisting of patients' RBCs and donor plasma and platelets at standardized hematocrit and platelet count. No differences were observed under these conditions at a shear rate of 300 s-1. When whole blood of patients was used, nonsignificant effect was observed at shear rates of 300 s-1 and 1,800 s-1. This was probably caused by the added noise due to variations in hematocrit and platelet number. These data demonstrate that isoxsuprine increases RBC deformability, and they suggest the possibility of decreasing platelet-vessel wall interaction in vivo by manipulation of RBC deformability.

Association Between Bleeding Time and Platelet Adherence to Artery Subendothelium

1984 ◽  
Vol 52 (02) ◽  
pp. 144-147 ◽  
Author(s):  
K S Sakariassen ◽  
P A Bolhuis ◽  
Margaretha Blombäck ◽  
L Thorell ◽  
Birger Blombäck ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Blood Platelets ◽  
Normal Subjects ◽  
Commercial Preparation ◽  
Normal Platelet ◽  
Platelet Adherence ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe efficacy of five different factor VUI-von Willebrand factor (FVIII-VWF) preparations in mediating adherence of blood platelets to damaged vessel walls was tested in an annular perfusion chamber utilizing human arteries and reconstituted blood.FVIII-VWF-purified by Sepharose CL-4B chromatography and von Willebrand factor prepared from this preparation by dissociation with 0.25 M CaCl2 followed by Sepharose CL-6B chromatography were equally effective in mediating platelet adherence as FVIII-VWF in cryoprecipitate and in plasma from normal subjects. A commercial concentrate of FVIII-VWF (Hemofil, Hyland) used for the treatment of haemophiliacs did not mediate platelet adherence at normal levels of FVIII-VWF related properties. A recently developed high-purity FVIII-VWF preparation (Concentrate II) containing multimers of high molecular weight normalized the platelet adherence. Platelet adherence in plasma obtained from two patients with von Willebrand’s disease (VWD) was impaired, but plasma samples obtained following treatment with Concentrate II mediated normal platelet adherence. The normalization of platelet adherence paralleled the normalization of the bleeding time.This platelet adherence assay offers an inexpensive and efficient in vitro tool to test the efficacy of FVIII-VWF preparations designed for VWD patients. Preparations such as cryoprecipitate and Concentrate II mediated the platelet adherence and normalized the bleeding time. The commercial preparation did not mediate platelet adherence and had no effect on the bleeding time.

scholarly journals Biomechanical Loading Comparison between Titanium and Unsintered Hydroxyapatite/Poly-L-Lactide Plate System for Fixation of Mandibular Subcondylar Fractures

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1557 ◽  
Author(s):  
Shintaro Sukegawa ◽  
Takahiro Kanno ◽  
Norio Yamamoto ◽  
Keisuke Nakano ◽  
Kiyofumi Takabatake ◽  
...  
Keyword(s):  
Shear Strength ◽  
Plate Fixation ◽  
In Vitro Study ◽  
Fixation Method ◽  
Mechanical Resistance ◽  
Titanium Plate ◽  
Biomechanical Behavior ◽  
Bioresorbable Plate ◽  
Plate System

Osteosynthesis absorbable materials made of uncalcined and unsintered hydroxyapatite (u-HA) particles, poly-l-lactide (PLLA), and u-HA/PLLA are bioresorbable, and these plate systems have feasible bioactive osteoconductive capacities. However, their strength and stability for fixation in mandibular subcondylar fractures remain unclear. This in vitro study aimed to assess the biomechanical strength of u-HA/PLLA bioresorbable plate systems after internal fixation of mandibular subcondylar fractures. Tensile and shear strength were measured for each u-HA/PLLA and titanium plate system. To evaluate biomechanical behavior, 20 hemimandible replicas were divided into 10 groups, each comprising a titanium plate and a bioresorbable plate. A linear load was applied anteroposteriorly and lateromedially to each group to simulate the muscular forces in mandibular condylar fractures. All samples were analyzed for each displacement load and the displacement obtained by the maximum load. Tensile and shear strength of the u-HA/PLLA plate were each approximately 45% of those of the titanium plates. Mechanical resistance was worst in the u-HA/PLLA plate initially loaded anteroposteriorly. Titanium plates showed the best mechanical resistance during lateromedial loading. Notably, both plates showed similar resistance when a lateromedially load was applied. In the biomechanical evaluation of mandibular condylar fracture treatment, the u-HA/PLLA plates had sufficiently high resistance in the two-plate fixation method.

scholarly journals Establishment of an in vitro thrombogenicity test system with cyclic olefin copolymer substrate for endothelial layer formation

2021 ◽  
Author(s):  
Skadi Lau ◽  
Yue Liu ◽  
Anna Maier ◽  
Steffen Braune ◽  
Manfred Gossen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Endothelial Cell ◽  
Cell Layer ◽  
Test System ◽  
Cyclic Olefin Copolymer ◽  
Flow Conditions ◽  
Cyclic Olefin ◽  
Platelet Adherence ◽  
Endothelial Cell Layer

AbstractIn vitro thrombogenicity test systems require co-cultivation of endothelial cells and platelets under blood flow-like conditions. Here, a commercially available perfusion system is explored using plasma-treated cyclic olefin copolymer (COC) as a substrate for the endothelial cell layer. COC was characterized prior to endothelialization and co-cultivation with platelets under static or flow conditions. COC exhibits a low roughness and a moderate hydrophilicity. Flow promoted endothelial cell growth and prevented platelet adherence. These findings show the suitability of COC as substrate and the importance of blood flow-like conditions for the assessment of the thrombogenic risk of drugs or cardiovascular implant materials. Graphic abstract

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