scholarly journals Local release of metalloproteinases and their inhibitors after a successful revascularisation procedure

2019 ◽  
Vol 17 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Raffaele Grande ◽  
Gioia Brachini ◽  
Antonio V. Sterpetti ◽  
Valeria Borrelli ◽  
Raffaele Serra ◽  
...  
Keyword(s):  
Revascularisation Procedure ◽  
Local Release

An in vivo Model for the Assessment of Acute Fibrinolytic Capacity of the Endothelium

1997 ◽  
Vol 78 (04) ◽  
pp. 1242-1248 ◽  
Author(s):  
David E Newby ◽  
Robert A Wright ◽  
Christopher A Ludlam ◽  
Keith A A Fox ◽  
Nicholas A Boon ◽  
...  
Keyword(s):  
Blood Flow ◽  
Substance P ◽  
Sodium Nitroprusside ◽  
Plasma Concentrations ◽  
In Vivo Model ◽  
Forearm Circulation ◽  
Von Willebrand ◽  
Local Release ◽  
Willebrand Factor

SummaryThe effects on blood flow and plasma fibrinolytic and coagulation parameters of intraarterial substance P, an endothelium dependent vasodilator, and sodium nitroprusside, a control endothelium independent vasodilator, were studied in the human forearm circulation. At subsystemic locally active doses, both substance P (2-8 pmol/min) and sodium nitroprusside (2-8 μg/min) caused dose-dependent vasodilatation (p <0.001 for both) without affecting plasma concentrations of PAI-1, von Willebrand factor antigen or factor VIII:C activity. Substance P caused local increases in t-PA antigen and activity (p <0.001) in the infused arm while sodium nitroprusside did not. At higher doses, substance P increased blood flow and t-PA concentrations in the noninfused arm. We conclude that brief, locally active and subsystemic infusions of intraarterial substance P cause a rapid and substantial local release of t-PA which appear to act via a flow and nitric oxide independent mechanism. This model should provide a useful and selective method of assessing the in vivo capacity of the forearm endothelium to release t-PA acutely.

scholarly journals Tubular Electrospun Vancomycin-Loaded Vascular Grafts: Formulation Study and Physicochemical Characterization

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2073
Author(s):  
Rossella Dorati ◽  
Enrica Chiesa ◽  
Mariella Rosalia ◽  
Silvia Pisani ◽  
Ida Genta ◽  
...  
Keyword(s):  
Methylene Chloride ◽  
Physicochemical Characterization ◽  
Fiber Surface ◽  
Solvent System ◽  
Burst Release ◽  
Sem Images ◽  
Composition And Structure ◽  
Medical Healthcare ◽  
Local Release ◽  
Preformulation Study

This work aimed at formulating tubular grafts electrospun with a size < 6 mm and incorporating vancomycin as an antimicrobial agent. Compared to other papers, the present study succeeded in using medical healthcare-grade polymers and solvents permitted by ICH Topic Q3C (R4). Vancomycin (VMC) was incorporated into polyester synthetic polymers (poly-L-lactide-co-poly-ε-caprolactone and poly lactide-co-glycolide) using permitted solvents; moreover, a surfactant was added to the formulation in order to avoid the precipitation of VMC on fiber surface. A preliminary preformulation study was carried out to evaluate solubility of VMC in different aqueous and organic solvents and its stability. To reduce size of fibers and their orientation, we studied a solvent system based on methylene chloride and acetone (DCM/acetone), at different ratios (80:20, 70:30, and 60:40). Considering conductivity of solutions and their spinnability, solvent system at a 80:20 ratio was selected for the study. SEM images demonstrated that size of fibers, their distribution, and their orientation were affected by the incorporation of VMC and surfactant into polymer solution. Surfactant allowed for the reduction of precipitates of VMC on fiber surface, which are responsible of the high burst release in the first six hours; the release was mainly dependent on graft structure porosity, number of pores, and graft absorbent capability. A controlled release of VMC was achieved, covering a period from 96 to 168 h as a function of composition and structure; the concentration of VMC was significantly beyond VMC minimum inhibitory concentration (MIC, 2 ug/mL). These results indicated that the VMC tubular electrospun grafts not only controlled the local release of VMC, but also avoided onset of antibiotic resistance.

LOCAL RELEASE OF CACHECTIN AND INTERLEUKIN 1 INTO THE PERITONEAL EXUDATE AFTER PERITONEAL INFLAMMATION IN HUMAN

1989 ◽  
Vol 71 (Supplement) ◽  
pp. A209
Author(s):  
J. Joris ◽  
P. Damas ◽  
Ph. Gysen ◽  
P. Franchimont ◽  
M. Lamy
Keyword(s):  
Interleukin 1 ◽  
Peritoneal Exudate ◽  
Peritoneal Inflammation ◽  
Local Release

Arginine vasopressin release from human platelets after irreversible aggregation

1990 ◽  
Vol 78 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Giovanni Anfossi ◽  
Elena Mularoni ◽  
Mariella Trovati ◽  
Paola Massucco ◽  
Luigi Mattiello ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Arginine Vasopressin ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Vasopressin Release ◽  
Irreversible Aggregation ◽  
Local Release

1. The release of arginine vasopressin from human platelets was investigated in platelet-rich plasma after irreversible aggregation induced by adenosine 5′-pyrophosphate, collagen, sodium arachidonate, thrombin and adrenaline in vitro. 2. Arginine vasopressin levels were significantly higher in the supernatant from stimulated platelet-rich plasma than from unstimulated samples, reaching 3.5 × 10−12 (range 1.6–12.5 × 10−12) mol/l in the absence of an aggregating agent, 8.8 × 10−12 (range 4.2–17.5 × 10−12) mol/l after adenosine 5′-pyrophosphate, 13.7 × 10−12 (2.2–63.2 × 10−12) mol/l after collagen, 7.8 × 10−12 (2.2–14.6 × 10−12) mol/l after sodium arachidonate, 7.8 × 10−12 (2.2–16.3 × 10−12) mol/l after thrombin and 12.2 × 10−12 (4.8–32.1 × 10−12) mol/l after adrenaline. 3. An arginine vasopressin level of 18 × 10−12 mol/l, which can be achieved physiologically, increased the sensitivity of platelets to adenosine 5′-pyrophosphate and collagen in vitro; the same concentration of arginine vasopressin caused a potentiation of the effect of catecholamines on the response of platelets to sodium arachidonate. 4. These results indicate that intraplatelet arginine vasopressin is released during aggregation and suggest that a local release of arginine vasopressin could occur after complete platelet aggregation in vivo.

scholarly journals Hydroxyapatite-ciprofloxacin delivery system: Synthesis, characterisation and antibacterial activity

2018 ◽  
Vol 68 (2) ◽  
pp. 129-144 ◽  
Author(s):  
Maria-Viorica Ciocilteu ◽  
Andreea Gabriela Mocanu ◽  
Adriana Mocanu ◽  
Catalin Ducu ◽  
Oana Elena Nicolaescu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Diffusion Controlled ◽  
Ft Ir ◽  
Inhibition Zones ◽  
Bacterial Growth Inhibition ◽  
Local Release

Abstract The main objective of this study was to synthesize hydroxyapatite-ciprofloxacin composites using a chemical precipitation method and to evaluate the properties and in vitro release profile of the drug from the hydroxyapatite-ciprofloxacin composites. Composite characterization was achieved by FT-IR, XRD and DLS. Ciprofloxacin determination was accomplished by HPLC, resulting in good incorporation efficiency of the drug (18.13 %). The in vitro release study (Higuchi model C = K t1/2 and Ritger-Peppas model, C = K t0.6) showed a diffusion-controlled mechanism. The antibacterial activity showed that the bacterial growth inhibition zones were approximately equal for the synthesis composites and for the mechanical mixture on the Staphylococcus aureus germ. The use of hydroxyapatite, which is a biocompatible, bioactive and osteoconductive material, with ciprofloxacin, which has good antibacterial activity in this composite, makes it suitable for the development of bone grafts. Furthermore, the synthesis process allows a slow local release of the drug.

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