scholarly journals FXIIa inhibitor rHA-Infestin-4: Safe thromboprotection in experimental venous, arterial and foreign surface-induced thrombosis

2016 ◽  
Vol 173 (5) ◽  
pp. 769-778 ◽  
Author(s):  
Frauke May ◽  
Jennifer Krupka ◽  
Marion Fries ◽  
Ina Thielmann ◽  
Ingo Pragst ◽  
...  
Keyword(s):  
Foreign Surface

Microbubble elimination during priming improves biocompatibility of membrane oxygenators

1978 ◽  
Vol 234 (5) ◽  
pp. H646-H652
Author(s):  
H. Osada ◽  
C. A. Ward ◽  
J. Duffin ◽  
J. M. Nelems ◽  
J. D. Cooper
Keyword(s):  
Surface Defects ◽  
Thrombus Formation ◽  
Membrane Surface ◽  
Initial Interaction ◽  
Membrane Oxygenators ◽  
Trapped Gas ◽  
Foreign Surface ◽  
Foreign Materials ◽  
Blood Elements ◽  
Priming Technique

We tested the hypothesis that platelet loss following blood contact with foreign materials is partly related to the presence of microbubbles of gas (gas nuclei) trapped in surface defects on the membrane material. Extracorporeal membrane oxygenator perfusions were conducted in two groups of sheep, with use of standard priming techniques for the oxygenator in one group and a new vacuum priming technique in the other group. The vacuum priming technique was developed to eliminate gas nuclei from the oxygenator surface. With denucleation priming, platelet loss during perfusion was markedly reduced, as was thrombus formation on the membrane surface. The platelet particle-size distribution curve showed a shift consistent with platelet aggregation with the standard priming technique but not with the vacuum priming technique. We conclude that the elimination of trapped gas nuclei from the membrane surface during priming reduces the initial interaction between blood elements and the foreign surface.

Hageman Factor in Plasma Foreign Surface Reactions

Nature ◽  
1958 ◽  
Vol 182 (4642) ◽  
pp. 1102-1103 ◽  
Author(s):  
J. MARGOLIS
Keyword(s):  
Surface Reactions ◽  
Hageman Factor ◽  
Foreign Surface

A Study of the Mass Transport Resistance of Glucose Across Rat Capsular Membranes

1987 ◽  
Vol 110 ◽  
Author(s):  
C. L. Freeman ◽  
K. G. Mayhan ◽  
G. J. Picha ◽  
C. K. Colton
Keyword(s):  
Connective Tissue ◽  
Mass Transport ◽  
Transport Properties ◽  
Critical Factor ◽  
Giant Cells ◽  
Fibrous Connective Tissue ◽  
Initial Attempt ◽  
Implant Surface ◽  
Tissue Factors ◽  
Foreign Surface

The interaction between a polymer or other foreign surface and soft tissue is determined by a variety of materials and tissue factors. After failing to engulf the foreign body, the classical response is to wall it off. First the site is invaded by macrophages and giant cells and then fibrous connective tissue is laid down. This fibrous connective tissue gradually replaces the cellular matrix and forms the capsule. The composition is mostly collagen and mucopolysaccharides with few cells in the mature capsule. It contains 75–80% water.When the implant surface represents a sensor and the transport of low molecular weight species across the capsule is necessary for meaningful measurement and response time, the mass transport resistance of the capsule may become a critical factor. This study represents an initial attempt to characterize the diffusion of glucose through fibrous capsules grown around silicone elastomer implants in a rat. Specifically, the study was designed to develop techniques to measure mass transport properties of tissue capsules, to use these techniques to determine effective glucose transport properties at two weeks, four weeks, and ten weeks after implant; and, to use these results along with histological examinations to gain an understanding of the factors which influence mass transport.

Reflections on Quantitative Gamma Imaging of Cell-Surface Interactions

2011 ◽  
Author(s):  
Robert C. Eberhart
Keyword(s):  
Imaging Techniques ◽  
Bacterial Colonization ◽  
Cell Interactions ◽  
Cellular Interactions ◽  
Surface Adhesion ◽  
Internal Organs ◽  
Cell Surface Interactions ◽  
Foreign Surface ◽  
Protein Cell ◽  
Adhesion Of Platelets

Molecular and cellular interactions with foreign surfaces can be noninvasively measured by isotope imaging techniques. Long available for probing cell behavior, these techniques are now employed in molecular studies of disease progression, such as Alzheimer’s [1]. This paper reviews results obtained by noninvasive dual label gamma scintigraphy for the transient adhesion of platelets and neutrophils to pump-oxygenators during cardiopulmonary bypass (CPB). In this application, characteristic cell-foreign surface adhesion and release patterns are observed during CPB in the pig, as a function of oxygenator design and surface chemistry. Cell distributions in internal organs post-CPB are also affected by these processes. This method can be adapted to other settings where the understanding of protein-cell interactions with native and foreign surfaces is at issue, including fibrinogen-cell interactions, bacterial colonization, etc.

IMPORTANCE OF CONFORMATIONAL CHANGE OF FIBRINOGEN INDUCED BY SURFACE ADSORPTION

1987 ◽  
Author(s):  
Lu He ◽  
Mc Mirshahi ◽  
J Soria ◽  
C Soria ◽  
M Mirshahi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Conformational Change ◽  
Surface Adsorption ◽  
Biological Properties ◽  
Tissue Type ◽  
Plasminogen Activation ◽  
Synthetic Material ◽  
Type Plasminogen Activator ◽  
Foreign Surface ◽  
Fibrinogen Molecule

Concerning the problem of blood - foreign surface interaction, it is a great importance to know whether fibrinogen adsorbed on a solid surface is conformationally modified.Therefore, we tested the reactivities of soluble and immobilized fibrinogen against monoclonal antibodies obtained by mouse immunisation with fibrin derivatives, by an immunoenzymological assay using a monoclonal antibody which recognized an epitope available in the D domain of the molecule, but which is poorly exposed on soluble undegraded fibrinogen, we found that the epitope became accessible to this monoclonal antibody after the binding of fibrinogen to polystyrene. We concluded that fibrinogen undergoes conformational change when absorbed to a solide phase.Conformational change of fibrinogen induced by immobilization on polystyrene may modify the biological properties of fibrinogen molecule. We have shown that after its adsorption, fibrinogen allows plasminogen activation by tissue type plasminogen activator (tpA) in a similar manner as fragment D and fibrin. Therefore, this modification of fibrinogen structure may allow the exposure of the epitope which is masked on native fibrinogen and demasked on fragment D and fibrin and which is essential for tpA-induced plasminogen activation.These results might be very useful in the screening of synthetic material used for grafts and extracorporeal circulation.A similar conformational change occurs when fibrinogen binds to ADP-treated platelets. Further work however will be required to determine whether conformational change is essential for ADP-induced platelet aggregation.

The Prothrombin Time in the Newborn: Effect of Contact Activation

1967 ◽  
Vol 17 (01/02) ◽  
pp. 214-221
Author(s):  
J. N Shanberge ◽  
T Matsuoka
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Contact Activation ◽  
Prothrombin Activity ◽  
Second Stage ◽  
Surface Contact ◽  
Adult Plasma ◽  
Conversion Time ◽  
Foreign Surface ◽  
The One

SummaryThe effect of foreign-surface contact on prothrombin conversion in adult plasma is compared to that of the newborn. The tests utilized in this comparison were the one-stage prothrombin time of Quick, the second stage of the thromboplastin generation test, and the prothrombin consumption test or the serum prothrombin time. In all of these there is much less acceleration produced by foreign-surface contact in the plasma of the newborn. Acceleration of the prothrombin conversion time is directly related to an increase in activity of factors VII and XL At no time could an increase in prothrombin activity be demonstrated. The decreased acceleration produced by foreign-surface contact in the plasma of the newborn is due primarily to a decreased level of factor VII as well as those factors necessary for its activation.

Kinetics Of Adsorption Of Proteins From Human Plasma Onto Foreign Surfaces

1981 ◽  
Author(s):  
J L Brash ◽  
S Uniyal
Keyword(s):  
Human Plasma ◽  
Surface Concentration ◽  
Kinetics Of Adsorption ◽  
Hydrophilic Surfaces ◽  
Adsorption Data ◽  
First Occurrence ◽  
Foreign Surface ◽  
Kinetics Of ◽  
Hydrophilic Materials ◽  
Zero Time

It is believed that adsorption of proteins is the first occurrence after blood/foreign surface contact. The composition of the protein layer, how it depends on surface properties, and how it changes with time are essentially unknown. The objective of this work was to develop data relevant to these questions. To this end, the quantities of �albumin, fibrinogen and IgG adsorbed on seven surfaces from human plasma as a function of time were measured. Human plasma (ACD anticoagulant) was diluted 1:4 with tris buffer. Purified proteins were labelled with iodine isotopes using the IC1 method and added to the plasma as tracers. Materials studied include several segmented polyether-urethanes, both hydrophilic and hydrophobic, glass, siliconized glass (SG), polystyrene (PS) and polyethylene (PE).The results may be summarized as follows: Fibrinogen: Within the 2 min to 3 h range of contact times, fibrinogen was not detected on any of the hydrophilic surfaces. On PE and SG the quantity adsorbed passed through a maximum between zero time and 2 min, then declined to near zero. Only on PS was adsorption substantial (0.4 μg cm-2) and constant with time, similar to that from a solution of fibrinogen. Albumin: Albumin was also not detected on the hydrophilic materials. In general its surface concentration when it was adsorbed (hydrophobic surfaces) was similar to that observed for solutions of albumin. IgG: IgG was detected on all surfaces. The surface concentrations were low (about 0.1 μg cm-2) compared to solution values but were generally constant with time.The following conclusions are drawn: (1) The plasma itself modifies adsorption. Therefore solution adsorption data cannot be used to predict plasma adsorption. (2) Contrary to popular belief, fibrinogen is absent or transient on most surfaces. (3) IgG appears to be ubiquitous as a component of protein layers adsorbed from Plasma.

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