scholarly journals Perspectives of Silicone Elastomere Implants Use in Preventing Postoperative Complications in Pelvic Exenteration for Advanced Cancers

2020 ◽  
Vol 71 (1) ◽  
pp. 45-50
Author(s):  
George Jinescu ◽  
Nicolae Bacalbasa ◽  
Andra Evtodiev ◽  
Iulia-Adelina Marin ◽  
Ioana Chiulan ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Degradation Products ◽  
Hydrolytic Degradation ◽  
Hardness Measurement ◽  
Body Fluids ◽  
Time Interval ◽  
Swine Model ◽  
Simulated Body Fluids

In this work, silicone elastomer films with potential to be used as implantable pelvic prosthesis were prepared and their bioactivity was studied both in vitro and in vivo environment. Tensile tests, hardness measurement and compression analysis revealed no significant decrease of the mechanical performance after in vitro hydrolytic degradation in simulated body fluids. The in vivo biocompatibility of films was assessed by implanting them subcutaneously in swine model, for 30 days. Their mechanical characteristics were similar to those of samples immersed in simulated body fluids, for the same time interval. No sign of fibrosis or necrosis were detected from the histological analysis performed on the tissue surrounding the films. In combination, these results indicate that this material has a very good resistance to mechanical and chemical fatigue, do not release any toxic degradation products and, therefore, has great potential as to be used further for preparation of pelvic prosthesis.

scholarly journals Electrospun polyester-urethane scaffold preserves mechanical properties and exhibits strain stiffening during in situ tissue ingrowth and degradation

2019 ◽  
Author(s):  
Hugo Krynauw ◽  
Rodaina Omar ◽  
Josepha Koehne ◽  
Georges Limbert ◽  
Neil H Davies ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mechanical Performance ◽  
Hydrolytic Degradation ◽  
Material Strength ◽  
Fibre Direction ◽  
Tissue Ingrowth ◽  
Polyester Urethane

AbstractConsistent mechanical performance from implantation through healing and scaffold degradation is highly desired for tissue-regenerative scaffolds, e.g. when used for vascular grafts. The aim of this study was the paired in vivo mechanical assessment of biostable and fast degrading electrospun polyester-urethane scaffolds to isolate the effects of material degradation and tissue formation after implantation. Biostable and degradable polyester-urethane scaffolds with substantial fibre alignment were manufactured by electrospinning. Scaffold samples were implanted paired in subcutaneous position in rats for 7, 14 and 28 days. Morphology, mechanical properties and tissue ingrowth of the scaffolds were assessed before implantation and after retrieval. Tissue ingrowth after 28 days was 83 ± 10% in the biostable scaffold and 77 ± 4% in the degradable scaffold. For the biostable scaffold, the elastic modulus at 12% strain increased significantly between 7 and 14 days and decreased significantly thereafter in fibre but not in cross-fibre direction. The degradable scaffold exhibited a significant increase in the elastic modulus at 12% strain from 7 to 14 days after which it did not decrease but remained at the same magnitude, both in fibre and in cross-fibre direction. Considering that the degradable scaffold loses its material strength predominantly during the first 14 days of hydrolytic degradation (as observed in our previous in vitro study), the consistency of the elastic modulus of the degradable scaffold after 14 days is an indication that the regenerated tissue construct retains it mechanical properties.

Silicon as an Active Biomaterial

1996 ◽  
Vol 452 ◽  
Author(s):  
L. T. Canham ◽  
C. L. Reeves ◽  
D. J. Wallis ◽  
J. P. Newey ◽  
M. R. Houlton ◽  
...  
Keyword(s):  
Body Fluids ◽  
Bulk Silicon ◽  
Porous Si ◽  
Vlsi Technology ◽  
Simulated Body Fluids ◽  
Silicon Microstructures ◽  
Si Films ◽  
In Vivo Assessment

AbstractThe response of a range of porous Si and poly Si films to storage in acellular simulated body fluids is summarised and its implications discussed. It is suggested that the combination of VLSI technology, micromachining and surface microstructuring achievable with silicon, could establish this prominent semiconductor as a very useful biomaterial by the next century. The ‘biocompatibility’ of a variety of silicon microstructures, and even bulk silicon has received surprisingly little study, but now warrants detailed in-vitro and in-vivo assessment.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

Accumulation of Macromolecular Particles in the Reticuloendothelial System (RES) Mediated by Platelet Aggregation and Disaggregation

1969 ◽  
Vol 22 (03) ◽  
pp. 496-507 ◽  
Author(s):  
W.G van Aken ◽  
J Vreeken
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Reticuloendothelial System ◽  
Caproic Acid ◽  
Carbon Particles ◽  
Carbon Clearance ◽  
Aggregation And Disaggregation ◽  
Platelet Aggregates

SummaryCarbon particles cause platelet aggregation in vitro and in vivo. Prior studies established that substances which modify thrombocyte aggregation also influence the rate at which carbon is cleared from the blood.This study was performed in order to elucidate the mechanism by which the carbon-platelet aggregates specifically accumulate in the RES.Activation of fibrinolysis by urokinase or streptokinase reduced the carbon clearance rate, probably due to generated fibrinogen degradation products (FDP). Isolated FDP decreased the carbon clearance and caused disaggregation of platelets and particles in vitro. Inhibition of fibrinolysis by epsilon-amino-caproic acid (EACA), initially accelerated the disappearance of carbon and caused particle accumulation outside the RES, predominantly in the lungs. It is supposed that platelet aggregation and locally activated fibrinolysis act together in the clearance of particles. In the normal situation the RES with its well known low fibrinolytic activity, becomes the receptor of the particles.

The Effects of Brinolase (Fibrinolytic Enzyme from Aspergillus Oryzae) on Platelet Aggregation of Dog and Man

1972 ◽  
Vol 28 (01) ◽  
pp. 031-048 ◽  
Author(s):  
W. H. E Roschlau ◽  
R Gage
Keyword(s):  
Platelet Aggregation ◽  
Aspergillus Oryzae ◽  
Degradation Products ◽  
Blood Platelet ◽  
Human Platelets ◽  
Fibrinolytic Enzyme ◽  
Inhibitory Effects ◽  
Blood Platelet Aggregation

SummaryInhibition of blood platelet aggregation by brinolase (fibrinolytic enzyme from Aspergillus oryzae) has been demonstrated with human platelets in vitro and with dog platelets in vivo and in vitro, using both ADP and collagen as aggregating stimuli. It is suggested that the optimal inhibitory effects of brinolase occur indirectly through the generation of plasma fibrinogen degradation products, without compromising platelet viability, rather than by direct proteolysis of platelet structures.

Endoscopic Surgery Training: Application of an in Vitro Trainer and in Vivo Swine Model

1993 ◽  
Vol 6 (4) ◽  
pp. 329-337 ◽  
Author(s):  
George E. Kopchok ◽  
Douglas M. Cavaye ◽  
Stanley R. Klein ◽  
Mark P. Mueller ◽  
Jeffrey L. Lee ◽  
...  
Keyword(s):  
Endoscopic Surgery ◽  
Swine Model ◽  
Surgery Training

Catheter microelectrode assembly for in-vivo and in-vitro voltammetric analysis of body fluids

Talanta ◽  
1983 ◽  
Vol 30 (2) ◽  
pp. 121-123 ◽  
Author(s):  
J. Wang ◽  
L.D. Hutchins ◽  
S. Selim ◽  
L.B. Cumming
Keyword(s):  
Body Fluids ◽  
Voltammetric Analysis

scholarly journals Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota

2015 ◽  
Vol 81 (17) ◽  
pp. 5880-5888 ◽  
Author(s):  
C. De Maesschalck ◽  
V. Eeckhaut ◽  
L. Maertens ◽  
L. De Lange ◽  
L. Marchal ◽  
...  
Keyword(s):  
Broiler Chickens ◽  
Degradation Products ◽  
Hydrolytic Degradation ◽  
Feed Additives ◽  
Gut Health ◽  
Feed Conversion ◽  
Content Type ◽  
Beneficial Effects ◽  
Coa Transferase

ABSTRACTIn broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon andClostridiumcluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level,Lactobacillus crispatusandAnaerostipes butyraticuswere significantly increased in abundance in the colon and cecum, respectively.In vitrofermentation of XOS revealed cross-feeding betweenL. crispatusandA. butyraticus. Lactate, produced byL. crispatusduring XOS fermentation, was utilized by the butyrate-producingAnaerostipesspecies. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function.

scholarly journals THE EFFECT OF RHEUMATOID FACTORS AND OF ANTIGLOBULINS ON IMMUNE HEMOLYSIS IN VIVO

1963 ◽  
Vol 117 (1) ◽  
pp. 105-125 ◽  
Author(s):  
Manuel E. Kaplan ◽  
James H. Jandl
Keyword(s):  
Protein Content ◽  
Blood Stream ◽  
Body Fluids ◽  
Red Cells ◽  
Rheumatoid Factors ◽  
Low Protein ◽  
Immune Hemolysis

Studies were undertaken in man and in the rat comparing the effects of rheumatoid factors and immune antiglobulins on red cells sensitized with incomplete antibodies. The interaction of immune antiglobulins with sensitized red cells produced (a) agglutination in vitro and (b) an accelerated sequestration of the sensitized cells in vivo. In contrast, rheumatoid macroglobulins, although capable of agglutinating Rh-sensitized red cells in vitro, did not modify their destruction in vivo. The failure of rheumatoid factors to function as antiglobulins in vivo appears to reflect their non-reactivity with sensitized cells in whole serum. It is suggested: (a) that the native (7S) gamma globulins of plasma competitively inhibit rheumatoid factors from reacting with fixed antibody in the blood stream; (b) that if these macroglobulins do indeed have pathogenetic activity, this may be limited to body fluids of low protein content.

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