Recovery Of Platelet Function After Aspirin Ingestion: In Vivo And In Vitro Studies

1981 ◽  
Author(s):  
B A Bradlow ◽  
N Chetty ◽  
M Birnbaum
Keyword(s):  
Platelet Function ◽  
Recovery Of Function ◽  
Platelet Rich Plasma ◽  
Recovery Period ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Partial Recovery ◽  
Mean Values

Blood was taken from normal volunteers before and two hours after a 600mg oral dose of aspirin (ASA). Platelet rich plasma (PRP) was prepared from both samples. Mixtures of normal and ASA treated PRP were tested for aggregation responses and for production of thromboxane B2 (TXB2) by RIA (New England Nuclear). Normal aggregation responses were found when the mixture contained 26% of normal platelets (NP) with ADP, 40% NP with adrenalin, 54% NP with collagen and 52% NP with arachidonic acid (AA)(Mean Values). TXB2 production in the mixtures increased when the proportion of normal platelets was raised above 10 to 30%. These findings indicate partial restoration of platelet function by an admixture of 10-20% NP to ASA treated platelets although 50% NP was necessary to restore all functions tested. In vivo studies on seven volunteers given 300mg ASA showed partial recovery of malondialdehyde production after 72 hours, partial return of aggregation responses to collagen, ADP, adrenalin and AA at 96 hours and partial or full return of aggregation responses in all subjects by 120 hours. Since new platelets enter the circulation at the rate of 10-15% per day the results of our in vitro studies suggest that some recovery of platelet function might occur as soon as 24 hours after a dose of ASA and full recovery within 3-5 days. The longer recovery period indicated by the in vivo studies may be attributable to the effect of ASA on megakaryocyte cyclooxygenase.Conclusion: ASA administered once every 24 hours may be sufficient to suppress platelet function adequately and continuously but partial recovery of function might occur 48-72 hours after ASA ingestion.

Transplantation of Adipose-derived Cells for Periodontal Regeneration: A Systematic Review

2019 ◽  
Vol 14 (6) ◽  
pp. 504-518 ◽  
Author(s):  
Dilcele Silva Moreira Dziedzic ◽  
Bassam Felipe Mogharbel ◽  
Priscila Elias Ferreira ◽  
Ana Carolina Irioda ◽  
Katherine Athayde Teixeira de Carvalho
Keyword(s):  
Systematic Review ◽  
Animal Models ◽  
Platelet Rich Plasma ◽  
Periodontal Regeneration ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Cell Sources ◽  
Study Designs

This systematic review evaluated the transplantation of cells derived from adipose tissue for applications in dentistry. SCOPUS, PUBMED and LILACS databases were searched for in vitro studies and pre-clinical animal model studies using the keywords “ADIPOSE”, “CELLS”, and “PERIODONTAL”, with the Boolean operator “AND”. A total of 160 titles and abstracts were identified, and 29 publications met the inclusion criteria, 14 in vitro and 15 in vivo studies. In vitro studies demonstrated that adipose- derived cells stimulate neovascularization, have osteogenic and odontogenic potential; besides adhesion, proliferation and differentiation on probable cell carriers. Preclinical studies described improvement of bone and periodontal healing with the association of adipose-derived cells and the carrier materials tested: Platelet Rich Plasma, Fibrin, Collagen and Synthetic polymer. There is evidence from the current in vitro and in vivo data indicating that adipose-derived cells may contribute to bone and periodontal regeneration. The small quantity of studies and the large variation on study designs, from animal models, cell sources and defect morphology, did not favor a meta-analysis. Additional studies need to be conducted to investigate the regeneration variability and the mechanisms of cell participation in the processes. An overview of animal models, cell sources, and scaffolds, as well as new perspectives are provided for future bone and periodontal regeneration study designs.

The Effect of Barbituric Acid Derivatives on Platelet Function in Vitro and in Vivo

1973 ◽  
Vol 30 (02) ◽  
pp. 315-326
Author(s):  
J. Heinz Joist ◽  
Jean-Pierre Cazenave ◽  
J. Fraser Mustard
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Barbituric Acid ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Primary Response ◽  
Sodium Pentobarbital ◽  
Barbituric Acid Derivatives

SummarySodium pentobarbital (SPB) and three other barbituric acid derivatives were found to inhibit platelet function in vitro. SPB had no effect on the primary response to ADP of platelets in platelet-rich plasma (PRP) or washed platelets but inhibited secondary aggregation induced by ADP in human PRP. The drug inhibited both phases of aggregation induced by epinephrine. SPB suppressed aggregation and the release reaction induced by collagen or low concentrations of thrombin, and platelet adherence to collagen-coated glass tubes. The inhibition by SPB of platelet aggregation was readily reversible and isotopically labeled SPB did not become firmly bound to platelets. No inhibitory effect on platelet aggregation induced by ADP, collagen, or thrombin could be detected in PRP obtained from rabbits after induction of SPB-anesthesia.

Focus on the therapeutic efficacy of 3BNC117 against HIV-1: In vitro studies, in vivo studies, clinical trials and challenges

2017 ◽  
Vol 52 ◽  
pp. 44-50 ◽  
Author(s):  
Zhi-Jun Liu ◽  
Jing Bai ◽  
Feng-Li Liu ◽  
Xiang-Yang Zhang ◽  
Jing-Zhang Wang
Keyword(s):  
Clinical Trials ◽  
Therapeutic Efficacy ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Hiv 1

scholarly journals Are Platelet Aggregation Tests the Best Way to Assess New Drugs for Arterial Disease

2018 ◽  
Vol 1 (1) ◽  
pp. 01-03
Author(s):  
Mark I. M. Noble
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Platelet Rich Plasma ◽  
New Drugs ◽  
In Vitro Test ◽  
In Vivo Efficacy ◽  
Experimental Animals ◽  
Stenosed Artery

Over many years, laboratory testing of platelet aggregability have been carried out in attempts to develop drugs that would prevent thrombosis in arteries. The problems encountered included the question of methodology. Blood samples have to be anticoagulated in order to study the platelets. Anti-coagulation with citrate and tests on derived platelet rich plasma did not correlate at all well with thrombus growth in the stenosed coronary arteries of experimental animals and citrate removes the calcium ions which are vital for platelet function. Anticoagulation with heparin also interfered with platelet function, so that now, hirudins are the preferred anticoagulant. However it was observed that if, instead of stimulating platelet aggregation with adrenaline or ADP, serotonin was applied to the preparation, very little aggregation took place in spite of serotonin 5HT2A antagonists being the most potent inhibitors of thrombus growth in experimental animals. Another indicator that primary platelet agggregation is not a predictor of in vivo efficacy was the finding that 5HT2A antagonism inhibited aggregate growth. In a stenosed artery the platelets are activated by increased shear stress and blood turbulence with release of platelet serotonin causing positive feedback activation of more platelets. At present, there does not seem to be a bench in vitro test that accurately predicts in vivo efficacy in stenosed artery occlusive thrombosis.

Comparative lyophilized platelet-rich plasma wafer and powder for wound-healing enhancement: formulation, in vitro and in vivo studies

2019 ◽  
Vol 45 (8) ◽  
pp. 1379-1387 ◽  
Author(s):  
Ghada E. Yassin ◽  
Marwa H. S. Dawoud ◽  
Reham Wasfi ◽  
Ahmed Maher ◽  
Ahmed M. Fayez
Keyword(s):  
Wound Healing ◽  
Platelet Rich Plasma ◽  
In Vivo Studies

The Control Of Antithrombotic Prophylaxis And Therapy: A Pro-Coagulant Effect Of Heparin

1981 ◽  
Author(s):  
E Szwarcer ◽  
R Giuliani ◽  
E Martinez Aquino
Keyword(s):  
Blood Coagulation ◽  
Antithrombin Iii ◽  
Fixed Time ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Clotting Factors ◽  
Platelet Poor Plasma ◽  
Normal Platelet

For studying heparin effect on blood coagulation and on inhibitors, the drug was added at increasing amounts to a normal platelet poor plasma (PPP), and to plasmas of patients with variable amounts of clotting factors (cirrhotic, pregnant, etc) -IN VITRO STUDIES-, and infused to the same individuals -IN VIVO STUDIES-. Modifications on two clotting assays (KCCT-TT) were compared to heparin potentiating effect on AntiXa (Denson & Bonnar tech).When studied IN VITRO, the sensibility of KCCT, TT, and AntiXa techniques for heparin measurement was similar. IN VIVO, an apparently greater sensibility using AntiXa technique was observed.For determining if this phenomena was related to a specific enhanced potentiating effect of the inhibitor against Xa, exerted by heparin IN VIVO, experiences were repeated IN VITRO and IN VIVO, measuring heparin effect on KCCT, TT, and on the inhibitor, studied against Xa and thrombin. A personal technique was used for the measurement of Antithrombin III heparin potentiating effect, using diluted platelet poor test plasma, heated (56°C 15’) and incubated with thrombin during a fixed time, and reading residual thrombin on citrated human PPP. IN VITRO, all techniques were similar in their ability to show heparin presence.IN VIVO, the potentiating effect of heparin on the inhibitor, measured against Xa or thrombin, was greater than the changes obtained on KCCT or TT.So, AntiXa-Antithrombin III techniques seem to be more sensitive for heparin measurement IN VIVO.This “dissociation” of results in between the potentiating effect on the inhibitor, that is not simultaneously exerted on global coagulation, is interpreted as a heparin pro-coagulant effect, exerted by the drug IN VIVO.

scholarly journals Engineering Silicone Rubbers for In Vitro Studies: Creating AAA Models and ILT Analogues With Physiological Properties

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
T. J. Corbett ◽  
B. J. Doyle ◽  
A. Callanan ◽  
M. T. Walsh ◽  
T. M. McGloughlin
Keyword(s):  
In Vitro Studies ◽  
In Vivo Studies ◽  
Aortic Tissue ◽  
Element Analysis ◽  
Future Design ◽  
Change Behavior ◽  
Physiological Properties ◽  
Diameter Change

In vitro studies of abdominal aortic aneurysm (AAA) have been widely reported. Frequently mock artery models with intraluminal thrombus (ILT) analogs are used to mimic the in vivo AAA. While the models used may be physiological, their properties are frequently either not reported or investigated. This study is concerned with the testing and characterization of previously used vessel analog materials and the development of new materials for the manufacture of AAA models. These materials were used in conjunction with a previously validated injection molding technique to manufacture AAA models of ideal geometry. To determine the model properties (stiffness (β) and compliance), the diameter change of each AAA model was investigated under incrementally increasing internal pressures and compared with published in vivo studies to determine if the models behaved physiologically. A FEA study was implemented to determine if the pressure-diameter change behavior of the models could be predicted numerically. ILT analogs were also manufactured and characterized. Ideal models were manufactured with ILT analog internal to the aneurysm region, and the effect of the ILT analog on the model compliance and stiffness was investigated. The wall materials had similar properties (Einit 2.22 MPa and 1.57 MPa) to aortic tissue at physiological pressures (1.8 MPa (from literature)). ILT analogs had a similar Young’s modulus (0.24 MPa and 0.33 MPa) to the medial layer of ILT (0.28 MPa (from literature)). All models had aneurysm sac compliance (2.62–8.01×10−4/mm Hg) in the physiological range (1.8–9.4×10−4/mm Hg (from literature)). The necks of the AAA models had similar stiffness (20.44–29.83) to healthy aortas (17.5±5.5 (from literature)). Good agreement was seen between the diameter changes due to pressurization in the experimental and FEA wall models with a maximum difference of 7.3% at 120 mm Hg. It was also determined that the inclusion of ILT analog in the sac of the models could have an effect on the compliance of the model neck. Ideal AAA models with physiological properties were manufactured. The behavior of these models due to pressurization was predicted using finite element analysis, validating this technique for the future design of realistic physiological AAA models. Addition of ILT analogs in the aneurysm sac was shown to affect neck behavior. This could have implications for endovascular AAA repair due to the importance of the neck for stent-graft fixation.

scholarly journals Inhibition of platelet function by A02131-1, a novel inhibitor of cGMP- specific phosphodiesterase, in vitro and in vivo

Blood ◽  
1996 ◽  
Vol 87 (9) ◽  
pp. 3758-3767 ◽  
Author(s):  
SM Yu ◽  
SY Tsai ◽  
SC Kuo ◽  
JT Ou
Keyword(s):  
Platelet Function ◽  
Platelet Rich Plasma ◽  
Atp Release ◽  
Camp Level ◽  
Cgmp Level ◽  
Prostaglandin D2 ◽  
Type I ◽  
Type V

The effect of A02131–1 [3-(5′-hydroxymethyl-2′-furyl)-1-benzyl thieno (3,2-c)pyrazole], a cGMP-specific phosphodiesterase (PDE) inhibitor, on platelet function was investigated. The compound was found to inhibit the aggregation of and adenosine triphosphate (ATP) release from human platelet-rich plasma and washed platelets that were induced by aggregation inducing drugs such as arachidonic acid (AA), collagen, U46619, platelet-activating factor (PAF), adenosine diphosphate (ADP) and A23187, and the inhibitory effect was concentration-dependent. A02131–1 also disaggregated the performed platelet aggregates induced by these inducers. Thromboxane B2 (TXB2) formations caused by collagen, PAF, ADP, and A23187 were inhibited by A02131–1 at concentrations that did not affect the AA-induced formation of TXB2 and prostaglandin D2 (PGD2). A02131–1 suppressed both the generation of inositol 1,4,5- triphosphate (IP3) and the increase of intracellular Ca2+ concentration stimulated by these aggregation inducers. A02131–1 was shown to increase the cAMP and cGMP levels in platelets and the extent was found to be dependent on concentration as well as time. A02131–1 increased the cAMP level much more slowly than the cGMP level. Activities of adenylate cyclase, guanylate cyclase, and PDEs (type I and III) were not altered by A02131–1. However, the activity of cGMP-specific PDE (type V) was inhibited by A02131–1. The antiplatelet aggregation activity and the effect on raising cAMP level of A02131–1 were both potentiated by prostaglandin E1 (PGE1). In the mouse tail bleeding test, A02131–1 was clearly shown to be more effective than dipyridamole in prolonging the tail bleeding time of conscious mice. These data indicate that A02131–1 is a cGMP-specific PDE (type V) inhibitor in human platelets.

Measurement of axial forces during emptying from the human stomach

1992 ◽  
Vol 263 (2) ◽  
pp. G230-G239 ◽  
Author(s):  
M. J. Vassallo ◽  
M. Camilleri ◽  
C. M. Prather ◽  
R. B. Hanson ◽  
G. M. Thomforde
Keyword(s):  
Axial Force ◽  
Longitudinal Axis ◽  
Force Transducer ◽  
Human Stomach ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Axial Forces

Our aim was to measure axial forces in the stomach and to evaluate their relation to circumferential contractions of the gastric walls and the emptying of gastric content. We used a combination of simultaneous radioscintigraphy, gastroduodenal manometry, and an axial force transducer with an inflatable 2-ml balloon fluoroscopically placed in the antrum. In vitro studies demonstrated that the axial force transducer records only antegrade forces along the longitudinal axis of this probe in an intensity-dependent manner. In vivo studies were performed in five healthy subjects for at least 3 h after ingestion of radiolabeled meals. When administered separately, the emptying of liquids or solids from the stomach is associated with generation of antral axial forces and coincident phasic pressure activity; however, almost 20% (average) of gastric axial forces during emptying of liquids or solids are unassociated with proximal or distal antral pressure activity ("isolated" forces). High amplitude antral axial forces and pressures occur during both lag and postlag emptying phases. During emptying of liquids, there is a trend for axial forces to be coincident more often with proximal than with distal antral pressure activity and vice versa for the emptying of solids (P = 0.015). These data suggest that when placed in the antrum, the transducer can semiquantitatively record axial forces during gastric emptying. By combining these observations with the data from in vitro studies, it appears that axial forces predominantly result from traction on the balloon by the longitudinal vector resulting from circumferential gastric contractions. The combination of radioscintigraphy and measurement of antral axial forces is a promising method to evaluate mechanical forces involved in the emptying of the human stomach.

Digestibility of Native and Modified Starches: In Vitro Studies with Human and Rabbit Pancreatic Amylases and In Vivo Studies in Rabbits

1985 ◽  
Vol 115 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Ping C. Lee ◽  
Stephen P. Brooks ◽  
Ok Kim ◽  
Leo A. Heitlinger ◽  
Emanuel Lebenthal
Keyword(s):  
In Vitro Studies ◽  
In Vivo Studies ◽  
Modified Starches
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