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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isolated liver perfusion was developed for the study of liver physiology and preservation. The recent development of new perfusion devices and appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in terms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers were perfused with autologous blood. Arterio-portal perfusions were carried out using an extracorporeal perfusion circuit with a hollow fibre membrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and University of Wisconsin (UW)] and two different oxygenation modalities. Liver function tests and histological studies were done. Our results revealed that a high partial oxygen pressure (PO2) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performance, i.e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxygenation. Flushing of the liver with Ringer's lactate or a macromolecular solution such as ELOHES was associated with severe liver cell injuries, as reflected by a marked rise in liver enzymes and histological lesions. Satisfactory results were obtained when UW solution was used for liver harvesting. We conclude that an appropriate liver preservation solution, normal blood gas values, and normal physiological arterio-portal pressure and blood flow are essential for appropriate liver function with preservation of liver architecture and of hepatocyte ultrastructures. Total bilirubin in bile and Factor V are sensitive indicators of good liver function.
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PMID:The isolated perfused porcine liver: assessment of viability during and after six hours of perfusion. 924 41

Mixed species biofilms of Klebsiella pneumoniae, Pseudomonas fluorescens, and Pseudomonas aeruginosa were grown in a flow cell fitted with two platinum wire electrodes. The biofilm growing on the wires reached a thickness of approximately 50 microm after 3 days. When a voltage was applied with oscillating polarity, the biofilm attached to the wire expanded and contracted. The biofilm expanded by approximately 4% when the wire was cathodic but was reduced to 74% of the original thickness when the wire was anodic. The phenomenon was reproduced by alternately flushing the flow cell with media adjusted to pH 3 and pH 10 with no electric current. At pH 10 the biofilm was unaltered, but it became compacted to 69% of the original thickness at pH 3. We explained these phenomena in terms of the molecular interactions between charged acidic groups in the biofilm slime and the bacterial cell walls. Contraction of the biofilm under acidic conditions may be caused by (i) the elimination of electrostatic repulsion from neutralization of negatively charged carboxylate groups through protonation and (ii) subsequent hydrogen bonding between the carboxylic acids and oxygen atoms in the sugars. Electrostatic interactions between negatively charged groups in the biofilm and the charged wire may also be expected to cause biofilm expansion when the wire was cathodic and contraction when the wire was anodic. The consequences of the explanation of the increased susceptibility of biofilm cells to antibiotics in an electric field, the "bioelectric effect," are discussed.
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PMID:Influence of electric fields and pH on biofilm structure as related to the bioelectric effect. 930 77

The total elimination of air represents a serious hurdle in modified atmosphere packaging of bakery products, due both to the high spin-rates of the packaging lines and, particularly, to the typical texture of bakery products which retain large quantities of air inside their porous structure. Simulating the gas-flushing modified atmosphere packaging with laboratory equipment and measuring the oxygen concentration directly inside bread rolls, by means of a gas analyser connected with the internal portion, it was possible to follow the rate of atmosphere substitution, evaluating the effects of different baking treatments (7, 12 and 23 min at 230 degrees C) and the role played by different gases (nitrogen, argon, helium, nitrous oxide and carbon dioxide). The oxygen content inside the products, plotted versus time, led to typical logistic 'dose-response' curves which made it possible to forecast the time needed to reach established values of residual oxygen concentration and to emphasize the effects of the different conditions used. The gas properties particularly affected the rate of oxygen substitution and the less water-soluble was the gas, the faster was the oxygen reduction; the larger was the gas molecule, the slower was the process. Also baking time was shown to have, to a different extent, some measurable effects on the rate of oxygen substitution and hence, its optimization as well as the choice of gas mixture can contribute to improve modified atmosphere packaging of bakery products.
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PMID:Minimizing the residual oxygen in modified atmosphere packaging of bakery products. 937 39

This study investigates the effects of mivacurium (3 times ED95) on neuromuscular block, intubation conditions and general safety in comparison with equipotent doses of atracurium and vecuronium. Following Ethical Care Committee approval and informed consent, 90 ASA I+II patients aged 18 to 65 were studied undergoing elective ENT surgery. Anaesthesia was induced with 1.5 mg/kg propofol and 0.2 mg/kg alfentanil and maintained through continuous infusion of propofol (8 to 10 mg . kg-1 . h-1) and nitrous oxide in oxygen. After achieving stable anaesthesia, the patients received bolus injections of mivacurium (0.20 mg/kg, n = 30), atracurium (0.69 mg/kg, n = 30) or vecuronium (0.14 mg/kg, n = 30) for endotracheal intubation. Intubation was attempted 120 s after drug application and the intubation conditions were assessed. Relaxation was recorded using peripheral nerve stimulation (Train of four). During the observation period, signs of histamine release, respiratory difficulty, cardiovascular events or other adverse signs were monitored. Onset of relaxation was longer for mivacurium (2.3 +/- 1.3 min) compared with atracurium (1.4 +/- 0.7 min) or vecuronium (1.3 +/- 0.3 min). Intubation conditions 120 s after drug application were good or very good in only 67% of cases given mivacurium compared with 90% given atracurium and 100% given vecuronium. The recovery time (DUR 25) was shorter in the mivacurium group (19.5 +/- 7.9 min) compared with atracurium (54.7 +/- 6.6 min) and vecuronium (44.3 +/- 8.6 min). Heart rate and blood pressure were similar in all groups. Facial flushing and mild bronchospasms as signs of histamine release resulted more often in the mivacurium (20%) and atracurium groups (23%) than in the vecuronium group (3%). In contrast to atracurium and vecuronium, recovery from mivacurium-induced neuromuscular blockade is rapid. However, the onset time after 3 times ED95 was significantly longer for mivacurium than for atracurium or vecuronium.
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PMID:[Mivacurium--a new muscle relaxant compared with atracurium and vecuronium]. 937 44

HP 228 is a synthetic heptapeptide analog of alpha-MSH that attenuates the production and release of inflammatory cytokines. The purpose of this study was to define HP 228's effects, alone and in combination with morphine, on resting ventilation and the ventilatory response to hypoxia and hypercarbia. Six healthy nonsmoking young adult males completed the four-session experiment. Subjects first underwent an initial training session. During subsequent sessions, each subject was tested for the respiratory effects of intravenous HP 228 (30 microg/kg), morphine (0.15 mg/kg), or HP 228 (30 microg/kg) plus morphine (0.15 mg/kg) in a double-blind placebo-controlled randomized balanced within-subjects experimental design. Sessions began with baseline measurement of resting ventilation, oxygen consumption, the isocapnic hypoxic ventilatory response (HVR), and normoxic hypercapnic ventilatory response (HCVR). A second set of respiratory measurements were obtained 10 min after completion of HP 228 or placebo infusion. Morphine or placebo was then administered and ventilatory responses were determined 15 and 40 min postinfusion. HP 228 produced cutaneous flushing, but had no significant effect on respiration or hemodynamics. Morphine significantly decreased metabolism, resting ventilation, and hypoxic and hypercarbic ventilatory responsiveness, independent of prior HP 228 administration. A seventh subject experienced a significant cardiac arrhythmia upon exposure to hypoxia after receiving both HP 228 and morphine and was withdrawn from further study. In conclusion, in this early Phase I clinical trial, HP 228 was found to neither depress ventilation nor augment morphine-induced respiratory depression in healthy young males.
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PMID:The respiratory effects of the cytokine regulating agent HP 228 alone and in combination with morphine in human volunteers. 951 83

The influence of molecular oxygen and oxygen radicals on the photoreactivity of the antimalarial drug primaquine (PQ) has been investigated. Oxygen is directly involved in photodecomposition of the drug. Flushing with helium gas prior to and during irradiation to suppress the oxygen level of the medium, retards the degradation rate of PQ (followed by HPLC) and leads to the formation of only two degradation products (identified by MS) compared to eight main- and several minor products under normal atmospheric conditions. Flushing with oxygen gas prior to and during irradiation to increase the oxygen content of the medium accelerates the degradation rate of PQ. PQ produces oxygen radicals (hydroxyl and superoxide) during photolysis, while the photoproducts of PQ seem likely to induce singlet oxygen formation (detected by addition of radical scavengers). Sensitization reactions involving singlet oxygen lead to decomposition of PQ (followed by HPLC). On the basis of our results, photochemical reaction mechanisms of PQ are postulated and discussed. At physiological conditions (aqueous, neutral pH, oxygen rich) PQ has a large potential to decompose after light absorption. The photoreaction seems to be initiated at the quinoline nitrogen. The ability to form an intramolecular hydrogen bond seems to be essential for the luminescence properties of the drug. Phosphorescence lifetime of PQ is about 5 microseconds. Fast chemical reactions may occur from the short-lived triplet state of the drug, but the excited compound can diffuse only a limited distance prior to deexcitation. This can be important concerning light-induced adverse effects which may appear after medication with PQ.
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PMID:Photoreactivity of biologically active compounds, XIV: influence of oxygen on light induced reactions of primaquine. 954 Jan 7

The Paratrend 7 sensor is a continuous intravascular blood gas sensor that consists of a miniaturized Clark-type PO2 electrode, fibreoptic pH and PCO2 optodes and a thermocouple, the monitor continuously displays the measured pH, PaO2 PaCO2 and temperature of the blood, and the calculated oxygen saturation, BE and SBC. After 7 years of caring for over 200 patients following insertion of the sensor, we describe our nursing experience with particular emphasis on the adequate fixation of the cannula, sensor system and connectors. The maintenance of the sensor through adequate flushing of the arterial line and care of the insertion site is described. Also outlined are the potential advantages to nursing practice of this new monitoring system, with particular reference to early warning of deterioration in respiratory function, closer control of mechanical ventilation and reduction in blood gas sampling and the errors inherent therein.
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PMID:Nursing care of the Paratrend 7 sensor. 956 51

In human heart transplantation limited myocardial ischemia duration remains one of the most restricting factors. A new approach towards prolongation of this duration is the combination of cardioplegic arrest and continuous Coronary Oxygen Persufflation (COP) with gaseous oxygen. This technique, which is based on former experiments, was applied in pig hearts which we transplanted orthotopically after a hypothermic preservation time of 14 hours. For cardioplegic arrest we used either Euro-Flush glutathion solution (EFG; n=5), University of Wisconsin solution (UW; n=5), modified Bretschneider HTK cardioplegic solution (mHTK; n=6). In preliminary experiments all three solutions had shown equal cardioprotective qualities. Hearts of the mHTK group were submitted to continuous COP during storage (mHTK+COP). After 14 hours of preservation and orthotopic transplantation the mHTK+COP hearts showed significantly improved cardiac functional recovery compared to hearts preserved by simple cold storage techniques. Hemodynamics measured after 3 hours reperfusion were significantly better in the mHTK+COP group compared to EFG and UW: dp/dtmax in % of baseline+/-standard deviation (SD): 85+/-22, 65+/-26, 36+/-15, CO in % of baseline: 68+/-13, 35+/-8, 39+/-8. Postoperative preload recruitable stroke work in the mHTK+COP hearts was: 51.4+/-23.1 mmHg compared to preoperative: 57.3+/-17.2. ATP of left-ventricular myocardium in the mHTK+COP group: 14.7+2.1 micromol/g dry weight was significantly higher compared to EFG: 10.3+/-4.5 and UW: 5.9+/-3.2. CK-MB in percent of CK in all groups showed no increase during postoperative reperfusion. This study suggests that COP may present an effective complement to cold storage techniques currently used in heart transplantation. Prior to clinical application further investigations regarding long-term survival and endothelial function are required.
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PMID:Coronary oxygen persufflation for long-term myocardial protection. 982 85

The authors examined the effects of ischemic preconditioning on lung preservation using a canine single left lung transplantation. Twelve adult mongrel dogs underwent left lung allotransplantation. Donor lungs were perfused and flushed with cold Euro-Collins solution (ECS) and stored at 4 degrees C ECS for 2 hours. Six donors were preconditioned by occuluding left lung hilum for 10 minutes and releasing for 15 minutes before flushing (Group PC); other six donors without ischemic preconditioning served as the controls (Group C). Left inferior pulmonary vein blood gas analysis, mean pulmonary artery pressure measurement and donor lung histology examination were made to evaluate the function of transplanted lung after transplantation. Oxygen tension at 2 hrs after reperfusion were significantly better in Group PC than in Group C (431 +/- 130 mmHg vs 246 +/- 66 mmHg, P < 0.05); mean pulmonary artery pressure was much lower in Group PC than in Group C after reperfusion (20.6 +/- 1.3 mmHg vs 36.9 +/- 3.1 mmHg, P < 0.01). Histological findings showed less injury in Group PC. These indicate that ischemic preconditioning combined with cold ECS perfusion is superior to cold ECS perfusion alone in canine lung preservation of 3 hours ischemia with 2 hours reperfusion.
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PMID:[Effects of ischemic preconditioning on protection of canine donor lung]. 986 10

Many lower vertebrates (reptilian and amphibian species) are capable of surviving natural episodes of hypoxia and hypothermia. It is by specific metabolic adaptations that anurans are able to tolerate prolonged exposure to harsh environmental stresses. In this study, it was hypothesized that livers from an aquatic frog would possess an inherent metabolic ability to sustain high levels of ATP in an isolated organ system, providing insight into a metabolic system that is well-adapted for low temperature in vitro organ storage. Frogs of the species, R. pipiens were acclimated at 20 degrees C and at 5 degrees C. Livers were preserved using a clinical preservation solution after flushing. Livers from 20 degrees C-acclimated frogs were stored at 20 degrees C and 5 degrees C and livers from 5 degrees C-acclimated frogs were stored at 5 degrees C. The results indicated that hepatic adenylate status was maintained for 96 h during 5 degrees C storage, but not longer than 4-10 h during 20 degrees C storage. In livers from 5 degrees C-acclimated animals subjected to 5 degrees C storage, ATP was maintained at 100% throughout the 96-h period. Warm acclimation (20 degrees C) and 20 degrees C storage resulted in poorer maintenance of ATP; energy charge values dropped to 0.50 within 2 h and by 24 h, only 24% of control ATP remained. Lactate levels remained less than 25 mumol/g dry weight in all 5 degrees C-stored livers; 20 degrees C-stored livers exhibited greater accumulation of this anaerobic endproduct (lactate reached 45-50 mumol/g by 10 h). The data imply that hepatic adenylate status is largely dependent on exposure to hypothermic hypoxia and although small amounts of ATP were accounted for by anaerobic glycolysis, there must have been either a substantial reduction in cellular energy-utilization or an efficient use of low oxygen tensions.
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PMID:Effects of hypothermic hypoxia on anaerobic energy metabolism in isolated anuran livers. 987 41


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