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Biomedical subjects

W Isselhard

Publications and source records attributed to W Isselhard.

At least 91 records · Page 5Linked to original sources
PubMed1981

Adenine nucleotide levels of canine kidneys during hypothermic aerobic or anaerobic storage in Collins solution.

The influence of retrograde oxygen persufflation (ROP) on renal adenine nucleotide, glucose and lactate contents was examined in canine kidneys during up to 5 days of hypothermic preservation. Organs with or without predamage in 30-min normothermic ischemia were preserved and the results compared to kidneys after hypothermic ischemic storage (HIS): ROP preservation resulted in a significantly higher maintenance of cellular energy-rich substances than in HIS with even normal adenine nucleotide contents and energy charge potentials for the first 24 h. As in HIS preservation of normal kidneys, where the total adenine nucleotide content (SAN) paralleled the loss of viability for the first 1-2 days, in ROP were SAN and even the lactate content also correlated to renal viability for 2-3 days. But in contrast to this correlation, which would favor adenine nucleotide determinations for viability testing, in predamaged kidneys no correlation of SAN or lactate with renal viability was found during HIS or ROP. Thus the determination of cellular energy-rich adenine nucleotides and lactate accumulation confirms the superiority of ROP over HIS preservation. But the SAN or lactate tests lose their prognostic value for posttransplant renal viability if normothermic ischemia precedes the preservation period.

Adenine Nucleotides↗
PubMed1980

Comparison of three methods of myocardial protection.

Ischemic arrest (45 minutes), injection cardioplegia (2-3 ml/kg body weight within 1 minute) using Cardioplegin (magnesium-aspartate-procaine-sorbitol) according to Kirsch (90 minutes), and infusion cardioplegia (30 ml/kg body weight within 5 to 7 minutes) employing solution LK 352 (sodium-potassium-magnesium-aspartate-sorbitol) according to Bretschneider (90 minutes) were investigated in dogs in order to evaluate their efficacy of protection during myocardial ischemia and their effects on post-ischemic cardiac function. Parameters studied were myocardial tissue levels of adenine nucleotides, creatine phosphate, total creatine and glycogen as well as heart rate, systemic pressure, cardiac output, LVEDP, left ventricular pressure-volume-work, dp/dtmax, t-dp/dtmax, (dp/dtmax)/IP, and Vpm. According to biochemical data corrected for differences in myocardial temperature during arrest, myocardial protection during aortic cross-clamping at a core temperature of 30 degrees C was increased 1.8-fold by Cardioplegin and 3.4-fold by LK 352 administration respectively when compared to ischemic arrest. Functional recovery was poor after ischemic arrest and better after Cardiplegin arrest. Infusion cardioplegia with LK 352 did not result in a post-arrest depression of functional parameters.

Animals↗
PubMed1980

A simple method for orthotopic liver transplantation in the rat. Cuff technique for three vascular anastomoses.

A simple method for orthotopic liver transplantation in the rat is described in detail. A cuff technique was applied to all anastomoses of the supra- and infrahepatic venae cavae and the portal vein. It simplified and shortened the implantation of the graft as well as eliminating the need for microvascular suture technique. In the last series of 20 transplants, the survival rate was 85% after 1 week and 55% after 2 months with normal hepatocellular function.

Animals↗
PubMed1980

[Deuterium oxide (D2O)--a protective factor for cellular stabilization in hypothermic preservation of the liver? (author's transl)].

Rat livers were preserved by ischemic hypothermic storage in extra- or intracellular type solutions for 24 h. A substitution of 85% of the tissue water by deuterium oxide (D2O) resulted in increased glycolytic energy production, better maintenance of the energy potential of the cells but a higher AMP loss, and a reduction of edema formation. Preservation using "retrograde oxygen persufflation" (ROP) resulted in optimal maintenance of the metabolic state which could be further influenced positively by D2O in the total nucleotide content.

Animals↗
PubMed1979

Free fatty acid and glucose metabolism during hypothermic perfusion of canine kidneys.

Canine kidneys were subjected to continuous nonpulsatile perfusion using 200 ml of a perfusate containing 50 g/l albumin. When optimal oxygenation was achieved, perfusate K+ contents were unchanged for 24 h, indicating adequate membrane function but tended to increase thereafter. Lowered oxygen pressures resulted in significant cellular K+ loss during the first hours of perfusion. During oxygenated perfusion, glucose and free fatty acids (FFA) were oxidized in considerable amounts with a preferential consumption of octanoate. A capacity for long-chain FFA oxidation became obvious when the octanoate had been used up, but the amount of these FFA in the perfusate depended preferentially on FFA being liberated from tissue lipids during the 1st day of perfusion. Glucose consumption rates were highest during the first 2 days of perfusion but the subsequent reduction of the metabolic rate was not accompanied by an accumulation of lactate. Thus medium-chain FFA and glucose should be supplied to the continuously perfused kidney in hypothermia and optimal oxygenation of the perfusate should be guaranteed. However, it seems to be unnecessary to supply exogenous long-chain FFA.

Albumins↗
PubMed1979

[Dye dilution test to determine leakage during regional perfusion in the treatment of malignant tumors of the extremities].

During regional perfusion of the extremity in the dog, the dye Evans blue (T 1824) was used as an indicator to control leakage from the isolated region into the systemic circulation. The rate of elimination of the dye was 10% +/- 2% per hour. A simulated leakage from the perfused region into the systemic circulation was determined with a sensitivity of 1,67%.

Animals↗
PubMed1979

[Hypothermic storage under aerobic conditions--the effect of different flushing solutions on kidney functional recovery].

Canine kidneys (n = 17) were flushed with COLLINS (C2), SACKS II, LAMBOTTE (KMgS), ROSS (hypertonic citrate), or RINGER glucose-mannitol solution following a 30-min period of normothermic ischemia. After 24 h hypothermic preservation with retrograde oxygen persufflation (ROP) and autotransplantation, the immediate functional recovery was determined using inulin and PAH clearance methods and compared with the normal contralateral kidney. While a good functional recovery was found in the COLLINS group, significantly exceeding results from hypothermic ischemic storage preservation, in experiments using other flush solutions ROP preservation resulted in only a small immediate function. Thus the experiments indicate that COLLINS solution C2 is the optimal flush solution for ROP preservation.

Aerobiosis↗
PubMed1979

[Myocardial metabolic status in various methods of inducing a reversible heart arrest].

In experiments with dogs, three different methods of inducing a reversible cardiac arrest were compared: (A) the ischemic arrest for 45 min, (B) the cardiac arrest for 90 min due to injection of Cardioplegin according to KIRSCH, and (C) the cardiac arrest for 90 min due to infusion of solution LK 352 according to BRETSCHNEIDER. The body temperature was reduced to 30 degrees C during the period of cardiac arrest. From the alterations in the adenylic acid system of the left ventricular myocardium at the end of the period of myocardial standstill and after 60 min of recovery, it can be deduced that the best myocardial protection is given by method C. Method A has the least effect.

Adenine Nucleotides↗
PubMed1979

Inhibition of platelet aggregation during hypovolemic hypotension by acetylsalicylic acid and artificial respiration.

In vivo measurement of platelet aggregation was performed by a previously described photoelectric method. It is shown that platelet aggregation induced by arterial hypotension can be inhibited by i.v. administration of ASA and by artificial respiration. The inhibition of platelet aggregation following artificial ventilation is significantly more pronounced than by ASA given 24 h prior to the beginning of the experiments. Different sources of platelet aggregation in venous and arterial blood are informative about the canine lung not only as a filter for aggregates but also as a source of aggregating substances.

Adenosine Diphosphate↗
PubMed1978

[Myocardial contractility in different methods of Cardioplegia. An experimental study (author's transl)].

In 22 mongrel dogs the protective effect on the myocardium of Bretschneider- and Kirsch-Cardioplegia (90 minutes of cardiac arrest) was studied and compared with ischemic arrest (45 minutes at hypothermia of 30 degrees C). Myocardial contractility was evaluated by the following indices of contractility: t--dp/dt max., Krayenbühl-Index of contractility and max. Vce. Depression of contractility of 40 % was observed after ischemic arrest and Kirsch-Cardioplegia, whereas in Bretschneider-Cardioplegia depression was only 7 %. Forty-five minutes after reperfusion contractility had returned to normal in the last group. It is concluded that Bretschneider-Cardioplegia results in little reduction of postischemic contractility, and has a good protective effect on the myocardium.

Animals↗
PubMed1978

[Muscle metabolic state in tourniquet syndrome in the rat after administration of the proteinase inhibitor aprotinin (author's transl)].

The metabolic status of rat skeletal muscle was examined after 5 h of unilateral ischemia of one hind leg and following 5 h of recirculation. There was no recovery, neither with nor without aprotinin (Trasylol) in different doses (35 000 and 125 000 KIE/kg b.w.). After 3 h of ischemia and 3 h of recirculation a significant recovery of the metabolic status occurred in animals without and with 35 000 KIE aprotinin/kg b.w. After injection of 125 000 KIE aprotinin the restoration of the metabolic status was significantly retarded. The metabolic situation of the contralateral, non-ischemic legs revealed--in comparison to normal levels--a significant deterioration in the latter group.

Animals↗
PubMed1978

[Metabolic status of acute myocardial infarction as a function of residual blood flow with and without revascularization].

In mongrel dogs anesthetized with Nembutal, the left anterior descending coronary artery was ligated for 2 h. The residual blood flow (RBF) was correlated with tissue levels of various myocardial metabolites after 1 and 24 h and 7 days of reperfusion. ATP and the sum of adeninnucleotides showed a better recovery with an increasing RBF. Initial increased value of creatine phosphate was followed by a decrease to subnormal values, which cannot be sufficiently explained. There was an accelerated overshoot beyond normal values in glycogen levels after 7 days with increasing RBF. After 7 days there was no recovery to normal values, and below a RBF of 5 ml/100 g/min metabolic recovery was poor.

Adenine Nucleotides↗
PubMed1978

[Metabolic status of hypothermically stored dog kidneys with various perfusion solutions and ischemia pretreatment].

In experiments on canine kidneys, cortical edema formation during hypothermic storage following a period of normothermic ischemia of up to 30 min duration was - according to the osmolality of the perfusion fluid - lower after flush perfusion with Sacks II solution than with Biotest-"Collins" solution or Ringer-mannitol solution, which resulted in the highest edema. The adenine nucleotide content fell corresponding to the duration of the hypothermic storage or the duration of an initial normothermic ischemia, but only small further changes were found during storage following initial normothermic damage. Moreover, with respect to the maintenance of nucleotide contents the strong hyperosmolar intracellular solutions were not superior to Ringer-mannitol solution of 330 mosmol/liter.

Adenine Nucleotides↗
PubMed1978

[Effect of adenosine and inosine on the metabolic status of preserved kidneys].

Isolated rat kidneys were preserved by continuous perfusion or retrograde oxygen persufflation in a medium of the extracellular type with and without addition of adenosine or inosine at 6 degrees C. After 4 and 24 hours of preservation the metabolic states was analysed. In the kidneys preserved by continuous perfusion, only adenosine was able to slow down the loss of nucleotides. With the retrograde oxygen persufflation the stock of high-energy phosphates could be preserved in any case, but no increase in the nucleotide content by neosynthesis was achieved by means of the addition of adenine nucleotide precursors.

Adenine Nucleotides↗