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

The present studies were designed to achieve a good maintenance of energy metabolism as a means of improving the quality of liver preservation in rats. For this purpose, investigation were made whether initial warm ischemia may affect energy metabolism during preservation and oxygen supply during initial cold flushing process may protect energy metabolism. The following are the results. Compared with non-oxygenated groups, the oxygenated groups during the initial cooling process proved to be effective in, 1) reducing the precipitous fall in the ATP level of the liver during the initial cooling process, 2) maintaining the higher ATP level for 8 hours of hypothermic immersion storage, 3) maintaining energy production for 24 hours in intermittent perfusion storage, 4) obtaining a more rapid recovery of energy production in rewarming and reperfusion after 8 or 16 hours of hypothermic immersion storage, 5) obtaining the higher ATP level by high flow rate of flushing. It may be concluded that maintenance of energy metabolism in the preserved liver is related to the degree of interference with energy metabolism during the initial cold flushing and this interference can be prevented by flushing with the oxygenated perfusate of high flow rate.
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PMID:[Experimental study on maintenance of energy metabolism of the preserved liver]. 661 23

The effect of 35 minutes of warm ischemia (37C) on renal function and adenine nucleotide content of canine kidneys preserved for 24 and 48 hours in Euro-Collins (EC) solution was investigated. In addition, the effect of donor pretreatment with intravenous mannitol, furosemide and methylprednisolone and the addition of adenosine triphosphate (ATP/MgCl2) to the EC flush and storage solution was studied. Donor pretreatment or the addition of ATP/MgCl2 to the flushing and storage solution did not significantly affect postautotransplant renal function of kidneys stored for 24 hours, although it improved tissue adenine nucleotide levels. Results after 48-hour preservation were significantly poorer. These experiments demonstrate that canine kidneys subjected to 35 minutes of warm ischemia time can be stored for 24 hours in EC solution and thereafter provide immediate life-sustaining function.
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PMID:Successful 24-hour preservation of the ischemic canine kidney with Euro-Collins solution. 675 92

The photoautotrophic cyanobacterium Anacystis nidulans was used to investigate the membrane transport of branched-chain, neutral amino acids and its dependence on photosynthetic reactions. The uptake of alpha-amino [1-14C]isobutyric acid and L-[1-14C]leucine followed Michaelis, Menten kinetics and resulted in an energy-dependent accumulation. As in bacteria, different uptake systems for neutral amino acids were present: two DAG (D-alanine, aminoisobutyric acid, and glycine) systems responsible for uptake of alpha-amino [1-14C]isobutyric acid, and one LIV (leucine, isoleucine, and valine) system, responsible for uptake of leucine. The low-affinity DAG system seemed to be dependent on the presence of Na+ ions. Uptake was enhanced by white light and by monochromatic light of 630 nm. In far red light (717 nm) with and without nitrogen flushing, considerable uptake dependent on light intensity and inhibition by dibromothymoquinone and by high concentrations of KCN were observed. Therefore, the energy generated by photosystem I reactions only could perform this membrane transport. The proton translocator carbonylcyanide m-chlorophenylhydrazone and N,N-dicyclohexylcarbodiimide as an ATPase inhibitor reduced amino acid uptake to a high degree. A pH dependence of aminoisobutyric acid and leucine uptake was obvious, with a maximum at pH 6 to 7 and some at a pH as high as 9.5. At higher pH, increasing concentrations of Na+ K+ and also of triphenylmethylphosphonium ions inhibited the transport of aminoisobutyric acid. These findings are consistent with the assumption that ATP from photosynthetic reactions drives a membrane-bound proton-translocating ATPase producing a proton motive force, consisting at higher pH chiefly in a delta psi amount, which promotes a secondary active H+ or Na+/amino acid symport carrier.
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PMID:Amino acid uptake and energy coupling dependent on photosynthesis in Anacystis nidulans. 680 40

The possible benefit of oxygenation during initial cold flushing was investigated as means of improving the quality of live preservation in rats. In five group of animals (total 61 experiments), the lives were flushed with different perfusates. Non-oxygenated groups included controls, Collins' solution alone and Collins' solution containing perfluorotributylamine (FC-43). In the oxygenated groups, Collins' solution alone and collins' solution containing FC-43 were oxygenated by bubbling. The hepatic ATP level and histopathological changes were used to assess the quality of liver preservation. Oxygenation during the initial cooling process proved to be effective in maintaining energy metabolism and preventing the characteristic microscopic changes of ischemic damage. Oxygenated Collins' solution containing FC-43 showed a much longer lasting effect compared with oxygenated Collins' solution alone. Without FC-43. Under light microscopy, in integrity of the liver appeared to be well preserved up to eight hours with the former solution. It is concluded that enhanced oxygenation with FC-43 in the initial cold flushing period can improve the quality of liver preservation.
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PMID:Maintenance of rat liver viability enhanced by cold flushing with oxygenated perfluorochemicals. 727 99

In previous experimental liver transplant studies, it was possible to extend cold ischaemic time (CIT) by using a flush/storage solution combining histidine, lactobionate and raffinose (HLR). In this study, energy metabolism, glycolytic substrate (glucose) and anaerobic end-product (lactate) were examined in rat liver over 24 h of cold storage to determine the mechanism of action of the HLR solution. In livers subjected to simple flush and storage with the HLR solution, levels of ATP and ADP were considerably higher than livers stored with modified UW throughout 24 h of storage; at 4 h of storage, ATP and ADP levels were 1.1 and 3.1 mumol/g for HLR solution versus 0.18 and 0.81 mumol/g for UW solution. Total adenylate contents (TA = ATP + ADP + AMP) also remained 1-2 mumol/g higher in HLR-treated livers than those preserved in UW; TA values ranged from 3.8 to 5.7 mumol/g. Glucose increased to 20-35 mumol/g by 10-24 h of storage (similar to the UW group). Lactate rose to almost twice that in livers stored in UW; total lactate accumulation was approximately 10.0 mumol/g. This study demonstrated that the combined HLR solution is able to prolong the maximum 'safe' CIT by increasing anaerobic metabolism and consequently preserving liver energetics. The second part of the experiment examined the effect of continuous perfusion (with/without O2) over the 1st h of cold ischaemia. Under current methods of liver flushing and excision, the 1st h of cold storage may be the critical time of metabolic 'adjustment' since most of the pH and ATP changes occur during this period.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:An underlying mechanism for improved liver preservation with a combined histidine-lactobionate-raffinose flush solution. 757 19

Rat hearts were preserved for 18 hr under totally ischemic storage conditions at 0-1 degree C with the commercially supplied EuroCollins, Bretschneider's HTK, and University of Wisconsin (UW) preservation solutions compared with our new preservation solution, Euro-Flush-glutathione solution, and a "refreshed" UW solution (UWG) with 3 mmol/L reduced glutathione added before use. Recovery of the organs was measured during 30 min of parabiotic reperfusion with whole blood of a host rat of the same inbred LEW strain, following an initial warm reflush for 5 min. Functional measurements were performed using a latex balloon in the left ventricle. The metabolic recovery was determined from the myocardium freeze-clamped at the end of reperfusion. The left ventricular pressure (LVP) amplitude during pacing to a heart rate of 300/min, as well as +dp/dtmax, -dp/dtmax, isotonic stroke volume, coronary flow, ATP, and ECP values, recovered significantly better after storage in Euro-Flush-glutathione solution (LVP: 63% of controls on average) compared with when the commercially available solutions were used (EuroCollins: 20%, HTK: 42% of controls in LVP). Hearts preserved in UW solution ViaSpan did not recover during the reperfusion period, when unfiltered solution was used. Filtered ViaSpan resulted in LVP recoveries of 38% of controls, while addition of reduced glutathione immediately before use (UWG) improved the effectivity of this solution significantly (LVP 63% of controls). Similar improvements were found for all other functional and metabolic parameters. Thus, the effectivity of UW solution ViaSpan depends upon extraction of the typical particles by a filtering procedure. Effectivity can be improved by a refreshment procedure with reduced glutathione immediately before use.
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PMID:Effectivity of freshly prepared or refreshed solutions for heart preservation versus commercial EuroCollins, Bretschneider's HTK or University of Wisconsin solution. 776 58

Rabbit hearts were subjected to 24-h cold ischaemic storage (at 0 degree-2 degrees C in melting ice) after initial flushing with either St Thomas' cardioplegic solution (STS) or modified lactobionate/raffinose solution (LR), and the status of phosphorylated energy metabolites was measured by 31phosphorus nuclear magnetic resonance (P NMR) spectroscopy. In both groups signals for ATP and phosphocreatine (PCr) were still detectable by 31P NMR after 24 h, and there was significantly more ATP in the LR group (P < 0.01). The hearts were then subjected to coronary reperfusion via an aortic cannula using the same storage solution (either STS or LR) at 6 degrees-8 degrees C, which was oxygenated. In both groups PCr recovered within 30 min of cold reperfusion, and by 60 min PCr was significantly higher in the LR group (P < 0.001). Also, levels of ATP were maintained at higher values during cold reperfusion i the LR group. These studies suggest two important points: (1) the general supply of phosphorylated high-energy intermediates of hearts during cold ischaemic storage is better preserved using LR, and (2) brief cold reperfusion may be used to restore energy metabolism in hearts before re-implantation.
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PMID:Resuscitation of cardiac energy metabolism in the rabbit heart by brief hypothermic reperfusion after preservation studied by 31P NMR spectroscopy. 788 58

The diagnostic accuracy and side effects of pharmacologic stress thallium myocardial scintigraphy with ATP infusion were studied in 172 patients with or without coronary artery disease. ATP was infused for five minutes at a rate of 0.16 mg/kg/min (group A) or 0.18 mg/kg/min (group B) via antecubital vein. One hundred and eleven (67 of group A, 44 of group B) of 172 patients underwent coronary arteriography (CAG). In 111 patients received CAG, overall sensitivity, specificity and accuracy of this method were 88%, 84% and 87%, respectively. In 67 patients of group A, these were 92%, 81% and 90%. In 44 patients of group B, 79%, 87% and 82% were documented (NS, between group A and B). Chest pain, flushing, bradycardia and ST depression were included in side effects caused by ATP infusion. At least one of these side effects were observed in 84% of the all 172 patients, 89% of group A and 75% of group B (NS). But, all of the side effects were spontaneously alleviated within two minutes without any therapy. In conclusion, pharmacologic stress myocardial scintigraphy with ATP infusion is very accurate and safe, and infusion rate of 0.16 mg/kg/min is optimal for this purpose.
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PMID:[The accuracy and side effects of pharmacologic stress thallium myocardial scintigraphy with adenosine triphosphate disodium (ATP) infusion in the diagnosis of coronary artery disease]. 793 82

Rewarming ischemia during implantation severely compromises posttransplant pancreas graft survival because the graft has already been subjected to warm and cold ischemia before implantation. The purpose of this study was to examine whether preservation of the pancreas graft by the two-layer method ameliorates rewarming ischemic injury of the graft during implantation using a canine model. After flushing with cold University of Wisconsin solution (UW), the pancreas grafts were preserved by the two-layer (UW/perfluorochemical [PFC]) method (group 1) or simple cold storage in UW (group 2) for 24 hr and then autotransplanted. In control, the pancreas grafts were flushed out with cold UW and immediately autotransplanted without preservation (group 3). After completion of vascular anastomosis, vascular clamp was not released until 90, 120, or 150 min of rewarming ischemia, including anastomosis time, had elapsed. After 90 min of rewarming ischemia, graft survival rates were 5/5, 100%, 5/5, 100%, and 5/5, 100%, in groups 1, 2, and 3, respectively. After 120 min, all the grafts in groups 2 and 3 failed (0/5, 0%, and 0/5, 0%, respectively); however, all the grafts in group 1 survived (5/5, 100%). Even after 150 min, 1 of 3 grafts in group 1 survived (1/3, 33%). After 24 hr preservation, tissue ATP levels of the grafts in group 1 were about 2-fold the reference values before harvesting (8.23 +/- 0.72 vs. 4.44 +/- 0.49 mumol/g dry weight, P < 0.05) and significantly higher compared with group 2 (8.23 +/- 0.72 vs. 1.76 +/- 0.52 mumol/g dry weight, P < 0.01). After 120 min of rewarming ischemia, tissue ATP levels in group 1 were 84% of the reference values and significantly higher compared with group 2 (3.75 +/- 0.25 vs. 1.57 +/- 0.48 mumol/g dry weight, P < 0.05). Two hours after reperfusion, ATP levels in group 1 were 42% of reference values but significantly higher compared with group 2 (1.86 +/- 0.36 vs. 1.03 +/- 0.18 mumol/g dry weight, P < 0.05). We conclude that the two-layer (UW/PFC) method ameliorates rewarming ischemic injury of the pancreas graft during implantation by increasing tissue ATP contents during preservation and consequently maintaining tissue ATP levels during implantation.
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PMID:Protective effect of preservation of canine pancreas by the two-layer (University of Wisconsin solution/perfluorochemical) method against rewarming ischemic injury during implantation. 814 Jun 27

We employed hyperosmotic concentrations of penetrating cryoprotective agents (CPA) to store the isolated rat hearts unfrozen at subzero temperatures. The effect of acute exposure to CPA was assessed by flushing the hearts with CP-14, a cardioplegic solution, containing methanol (MeOH), ethanol (EtOH), ethylene glycol (EG), or propylene glycol (PG) for 2 min and reperfusing immediately with Krebs-Henseleit buffer in a working-heart model. The maximal doses that did not cause irreversible suppression of heart function were: MeOH, 1.78 M; EtOH, 1.27 M; EG, 0.84 M; and PG, 0.87 M. For nonfreezing storage, the hearts were flushed with CP-14 containing the highest tolerable concentrations of MeOH, EtOH, EG, or PG, stored for 6 h at -3.7, -2.8, and -1.4 degrees C, respectively, and then reperfused. Control cardiac output (CO) was 76.2 +/- 1.8 ml/min. Post-reperfusional recovery of CO was 86% in MeOH hearts, 82% in EtOH hearts, 76% in EG hearts, and 79% in PG hearts. Thus MeOH offered not only the least cardiac-suppressing effect but the lowest nonfreezing storage temperature. When storage time was extended, recovery and myocardial ATP level decreased with time in hearts flushed with CP-14 + 1.78 M MeOH and stored at -3.7 degrees C. The decay of function was faster than the decay of ATP level, suggesting energy was better preserved than function. The low return of function, however, may be related to CPA toxicity, osmotic stress, and ischemia/reperfusion injury. Nonfreezing storage at subzero temperatures using these CPAs may provide a novel approach to long-term cardiac preservation.
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PMID:Subzero nonfreezing storage of the mammalian cardiac explant. I. Methanol, ethanol, ethylene glycol, and propylene glycol as colligative cryoprotectants. 840 87


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