28 research outputs found
Action of extracellular proteases of aspergillus flavus and aspergillus ochraceus micromycetes on plasma hemostasis proteins
In this study, we investigated the properties of proteolytic enzymes of two species of Aspergillus, Aspergillus flavus 1 (with a high degree of pathogenicity) and Aspergillus ochraceus L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both Aspergillus fully hydrolyzed thrombi in 120â180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin
Effect of Proteinase from Aspergillus fumigatus on Blood Plasma Proteins
Abstract: Extracellular proteinase of the opportunistic Aspergillus fumigatus D-1 strain (molecular weight ~33 kDa, pI 4.6) was isolated. It was shown that proteinase hydrolyzes casein, fibrin, fibrinogen, albumin, and hemoglobin to varying degrees. However, proteolytic activity with respect to globular proteins of blood plasma was comparable to fibrinolytic activity. Proteinase did not coagulate human fibrinogen and bovine fibrinogen; it also did not coagulate human and rabbit blood plasma without dilution and when diluted twice. The plasminogen-activating activity of A. fumigatus D-1 extracellular proteinase was found, which may indicate its ability to indirect fibrinolysis
Enhanced extracorporeal CO2 removal by regional blood acidification : Effect of infusion of three metabolizable acids
Acidification of blood entering a membrane lung (ML) with lactic acid enhances CO2 removal (VCO2ML). We compared the effects of infusion of acetic, citric, and lactic acids on VCO2ML. Three sheep were connected to a custom-made circuit, consisting of a Hemolung device (Alung Technologies, Pittsburgh, PA), a hemofilter (NxStage, NxStage Medical, Lawrence, MA), and a peristaltic pump recirculating ultrafiltrate before the ML. Blood flow was set at 250 ml/min, gas flow (GF) at 10 L/min, and recirculating ultrafiltrate flow at 100 ml/min. Acetic (4.4 M), citric (0.4 M), or lactic (4.4 M) acids were infused in the ultrafiltrate at 1.5 mEq/min, for 2 hours each, in randomized fashion. VCO2ML was measured by the Hemolung built-in capnometer. Circuit and arterial blood gas samples were collected at baseline and during acid infusion. Hemodynamics and ventilation were monitored. Acetic, citric, or lactic acids similarly enhanced VCO2ML (+35%), from 37.4 \ub1 3.6 to 50.6 \ub1 7.4, 49.8 \ub1 5.6, and 52.0 \ub1 8.2 ml/min, respectively. Acids similarly decreased pH, increased pCO2, and reduced HCO3- of the post-acid extracorporeal blood sample. No significant effects on arterial gas values, ventilation, or hemodynamics were observed. In conclusion, it is possible to increase VCO2ML by more than one-third using any one of the three metabolizable acids
Action of Extracellular Proteases of Aspergillus flavus and Aspergillus ochraceus Micromycetes on Plasma Hemostasis Proteins
In this study, we investigated the properties of proteolytic enzymes of two species of Aspergillus, Aspergillus flavus 1 (with a high degree of pathogenicity) and Aspergillus ochraceus L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both Aspergillus fully hydrolyzed thrombi in 120â180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin
Extracorporeal carbon dioxide removal enhanced by lactic acid infusion in spontaneously breathing conscious sheep
Background: The authors studied the effects on membrane lung carbon dioxide extraction (VCO2ML), spontaneous ventilation, and energy expenditure (EE) of an innovative extracorporeal carbon dioxide removal (ECCO2R) technique enhanced by acidification (acid load carbon dioxide removal [ALCO2R]) via lactic acid. Methods: Six spontaneously breathing healthy ewes were connected to an extracorporeal circuit with blood flow 250 ml/min and gas flow 10 l/min. Sheep underwent two randomly ordered experimental sequences, each consisting of two 12-h alternating phases of ALCO2R and ECCO2R. During ALCO2R, lactic acid (1.5 mEq/min) was infused before the membrane lung. Caloric intake was not controlled, and animals were freely fed. VCO2ML, natural lung carbon dioxide extraction, total carbon dioxide production, and minute ventilation were recorded. Oxygen consumption and EE were calculated. Results: ALCO2R enhanced VCO2ML by 48% relative to ECCO2R (55.3 \ub1 3.1 vs. 37.2 \ub1 3.2 ml/min; P less than 0.001). During ALCO2R, minute ventilation and natural lung carbon dioxide extraction were not affected (7.88 \ub1 2.00 vs. 7.51 \ub1 1.89 l/min, P = 0.146; 167.9 \ub1 41.6 vs. 159.6 \ub1 51.8 ml/min, P = 0.063), whereas total carbon dioxide production, oxygen consumption, and EE rose by 12% each (223.53 \ub1 42.68 vs. 196.64 \ub1 50.92 ml/min, 215.3 \ub1 96.9 vs. 189.1 \ub1 89.0 ml/min, 67.5 \ub1 24.0 vs. 60.3 \ub1 20.1 kcal/h; P less than 0.001). Conclusions: ALCO2R was effective in enhancing VCO2ML. However, lactic acid caused a rise in EE that made ALCO2R no different from standard ECCO2R with respect to ventilation. The authors suggest coupling lactic acid-enhanced ALCO2R with active measures to control metabolism
Modular extracorporeal life support : effects of ultrafiltrate recirculation on the performance of an extracorporeal carbon dioxide removal device
The combination of extracorporeal carbon dioxide removal (ECCO2R) and hemofiltration is a possible therapeutic strategy for patients needing both lung and renal support. We tested the effects of the recirculation of ultrafiltrate on membrane lung (ML) CO2 removal (VCO2ML). Three conscious, spontaneously breathing sheep were connected to a commercially produced ECCO2R device (Hemolung; Alung Technologies, Pittsburgh, PA) with a blood flow of 250 ml/min and a gas flow of 10 L/min. A hemofilter (NxStage, NxStage Medical, Lawrence, MA) was interposed in series after the ML. Ultrafiltrate flow was generated and recirculated before the ML. We tested four ultrafiltrate flows (0, 50, 100, and 150 ml/min) for 25 min each, eight times per animal, resulting in 24 randomized test repetitions. We recorded VCO2ML, hemodynamics and ventilatory variables, and natural lung CO2 transfer (VCO2NL) and collected arterial and circuitry blood samples. VCO2ML was unchanged by application of ultrafiltrate recirculation (40.5 \ub1 4.0, 39.7 \ub1 4.2, 39.8 \ub1 4.2, and 39.2 \ub1 4.1 ml/min, respectively, at ultrafiltrate flow of 0, 50, 100, and 150 ml/min). Minute ventilation, respiratory rate, VCO2NL, and arterial blood analyses were not affected by ultrafiltrate recirculation. In the tested configuration, ultrafiltrate recirculation did not affect VCO2ML. This modular technology may provide a suitable platform for coupling CO2 removal with various forms of blood purification