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Biomedical subjects

W Isselhard

Publications and source records attributed to W Isselhard.

At least 109 records · Page 6Linked to original sources
PubMed1978

[Energy metabolism of the intestinal wall in ileus].

In dogs, a segment of an aborrally occluded small intestine was anastomosed to the right colic flexure; thus, distal to the trapping ileocecal valve a local intestinal obstruction developed within a week in the small and large intestines, which locally stimulates the ileus situtation in man. Distrubances of the energy metabolism, as demonstrated by significant changes in the adenylic acid and phosphocreatine system, were more intensive in the mucosal layers of the small intestine than in those of the large intestine, whereas the smooth muscle layers were unaffected. The results reflect different disturbances of blood flow, energy needs, and adaptability of intestinal mucosa and musculature.

Adenine Nucleotides↗
PubMed1978

[Inhibition of thrombocyte aggregation in hemorrhagic shock using acetylsalicylic acid and mechanical ventilation].

Platelet aggregation in flowing venous and arterial blood during hypovolemic hypotension is followed by a previously described photoelectric method. It is shown that platelet aggregation can be inhibited by acetylsalicyclic acid (ASA) and by artificial ventilation. The inhibition of platelet aggregation by artificial ventilation is significantly more pronounced than that by ASA. That different times are needed for platelet aggregation in venous and arterial blood in dogs treated with ASA and with artificial ventilation is informative about the canine lung not only as a filter for aggregates but also as a source of aggregating substances.

Animals↗
PubMed1977

[Comparative study of energy metabolism of the skeletal muscles in man, dogs and rats during long-term ischemia].

A comparative investigation was made on muscle tissue of man, dog and rat during ischemia of five hours duration. The content of energy rich phosphates was measured. The ATP level decreased after two hours ischemia to 68% in man, to 45% in the dog, and to 23% in the rat. By five hours it had fallen further to 25% in man, 9% in the dog and only 1% in the rat. It is concluded that human muscle has a higher tolerance to ischemia.

Adenosine Diphosphate↗
PubMed1977

[Increased myocardial adenine nucleotides induced by adenosine].

The tissue of adenine nucleotides in the myocardium of rabbits, rats and dogs can be raised up to 40% by the infusion of adenosin. This increase is a function of the applied dose, the duration and the mode of application of adenosin; it does not result from the adenosin-induced reduction in cardiac work.

Adenine Nucleotides↗
PubMed1976

[Lipid and phospholipid content of canine liver tissue after portacaval anastomosis with or without additional arterialization of the intrahepatic portal vein].

The concentration of phospholipids and total lipids was determined 4 weeks after a portocaval shunt (PCS) in liver tissue of adult mongrel dogs. The concentration of total lipids increased from 33.5 +/- 3.6 to 71.2 +/- 6.9 mg/g ww, whereas the concentration of phospholipids declined from 26.1 +/- 3.1 to 19.8 +/- 7.8 mg/g ww. These changes are not observed when, in addition to the PCS, a pressure-adapted arterialization of the liver is established. They are therfore caused by the decreased blood supply to the liver after PCS alone.

Animals↗
PubMed1976

[Preservation of dog limbs through hypothermic perfusion].

Different methods of preservation are examined in long-lasting extremity ischemia in dogs. After preservation of 10 h duration by hypothermia and perfusion the status of energy-rich phosphates and pH was equivalent to the status after 2 h of ischemia under control conditions.

Animals↗
PubMed1976

[The effect of n-butanol on the metabolic status of some organs of rats and the circulation of rabbits].

Rats received n-butanol i.m. in a dose of 0.1 g/kg body weight/die during 50 days. The metabolic status of some organs was examined and compared to that of rats which in control experiments had received 0.9% NaCl-colution in an equivalent volume (double blind experiments). The tissue levels of metabolites of the adenylic acid-creatine phosphate system, of glycogen, glucose and lactate exhibited no significant differences in both the groups. In the liver the tissue level of glycogen, free creatine and total creatine was significantly elevated in rats which had received n-butanol. In concious rabbits the effect of n-butanol on circulatory parameters was investigated in double blind experiments. n-butanol was without a significant effect in a dosage of 0.008 g/kg. A dosage of 0.033 g/kg and particularly of 0.1 g/kg resulted in a transitory decrease in the heart rate and the systolic and especially diastolic blood pressure.

Animals↗
PubMed1976

[Influence of fatty-acid and glucose content of the perfusate on the energy metabolism of the preserved canine kidney].

Thirty-seven canine kidneys were preserved by hypothermic low flow perfusion for 24-120 h with solution I containing albumin, free fatty acids, and glucose, or with solution II containing Haemaccel without free fatty acids or glucose. Following 48 h preservation the renal ATP and SAN content was identical in both groups, irrespective of the availability of substrates from the perfusate.

Animals↗
PubMed1975

[Cerebral blood flow in rabbits during hypoperfusion of the brain. Flow distribution and methodological problems (author's transl)].

Brains of rabbits were perfused by arterial blood via the internal carotids after ligation of vertebral and external carotid arteries. The effect of the reduction of cerebral perfusion volume on cerebral blood flow was studied by recording the clearance of Krypton-85 from the brains. The clearance curves obtained by recording the gamma radiation of the Krypton-85 represented the sum of tissue clearances from the whole brain (about 10 g) and about 45 g of extracerebral tissue and so were not representative of cerebral or cortical bloow flow. Using external beta-counting the cortical blood flows calculated from the tissue-clearance curves reached mean values of 87 and 159 ml/100 g/min in perfusions with 12 and 18 ml/min respectively. But during reduced cerebral perfusion (2 ml/min) the clearance curves gave cortical blood flow values of 56 ml/100 g/min on the average and so exceeded the values calculated from the perfusion volume (2 ml/min) and the brain-weight (10 g) two to three times. It is concluded that regions of nonperfusion exceeding 50% of the cerebral tissue coexisted with adequately perfused areas. In hypoperfusion the cortical metabolic state was sufficiently correlated with the perfusion volume, but no correlation existed with the cortical blood flow calculated from the clearance curves.

Animals↗
PubMed1975

Metabolic and structural recovery of left ventricular canine myocardium from regional complete ischemia.

The capacity for recovery of the normothermic left ventricular myocardium from a regional complete ischemia (RCI) was investigated using changes in the myocardial metabolic status (ATP, ADP, AMP, creatine phosphate (CrP), free creatine, glycogen, glucose, lactate) and alterations of the morphology as parameters. In dogs, an area of the anterior wall of the left ventricular myocardium was temporarily deprived completely of its blood supply by 5--7 overlapping ligatures extending into the heart cavity. The metabolites of the adenylic acid-CrP system returned to normal tissue levels after 30 and 60 min of RCI within 14 and 35 days of recovery, respectively; restoration averaged 82% after 100 min, 74% after 140 min, and 38% after 180 min of RCI after 5 weeks of recovery. At the same time glycogen amounted to 163% after 100 min, 114% min, and 65% after 180 min of RCI. The biochemical data correlated well with the structural changes in the affected myocardium, especially with the amount of de- and regenerating heart muscle cells. These obviously were functionally defect and were not comparable with normal structured and functioning heart muscle cells.

Adenosine Diphosphate↗
PubMed1975

Metabolic patterns in several tissues of newborn rabbits during ischemia.

The metabolic states of various tissues of newborn rabbits were studied before and after periods of ischemia of 5-40 min. The contents of substances of the energy distributing adenylic acid-creatine phosphate system as well as glycogen, glucose and lactate were determined and the results are discussed in comparison with the well-known values from ischemic tissues of adult rabbits. The preservation of high energy phosphates as well as the rate of glycolytic energy production during the course of ischemia was quite identical in the myocardium of newborns and adults in contrast to the different ability of newborn and adult rabbits to maintain circulation in anaerobic conditions. In the central nervous system the ATP contents decreased to very low levels within a few minutes in both groups although the glycolytic energy production was rather different. But the larger amounts of adenine nucleotides present in the newborns at any time of ischemia indicate a better chance of postischemic recovery. In the livers and the kidneys of the newborns higher rates of glycolytic energy production led to better preservation of the energy-rich substances while in skeletal muscle and the lung only slight differences occurred between newborns and adults.

Adenine Nucleotides↗
PubMed1975

[Effect of pO2 in perfusate on metabolism of preserved dog kidneys].

In 48 canine kidneys submitted to an ischemia of 2 min duration normal cortical ATP values with a nearly unchanged content of total adenine nucleotides (SAN) were resumed by a five minute gravity perfusion. During the following 24 hours of low flow perfusion at 6 degrees C the extent of preservation of ATP and SAN correlated with the arterial oxygen pressure of the perfusate.

Adenine Nucleotides↗
PubMed1975

[Controlled hypothermia of ischemic extremities for the prevention of tourniquet shock].

The tourniquet-shock in dogs was produced after recirculation of ischemically stressed bilateral hind limbs. 4 of 7 dogs died within 5 hours after release of the tourniquets. The cause of heart failure could be defined by hypercaliaemia, metabolic acidosis and hemoconcentration. The development of tourniquet-shock could be suppressed by hypothermic preservation of the ischemic extremities.

Acidosis↗
PubMed1975

Effect on myocardial metabolic pattern of local complete and incomplete ischemia.

After local complete ischemia at normothermia of 60, 100, 140, and 180 min duration the status of the adenylic acid-creatine phosphate system in the canine myocardium recovered to 98, 85, 74, and 30 percent of the control values, whereas glycogen was restored even more. In the infarcted myocardium the extent of alterations of the metabolic status was a function of the residual blood flow. Deviations from a regular metabolic status developed if the blood flow dropped below about 35 ml/min/100 gm. This critical flow rate is expected to vary with the energy requirement of the heart, but it is in keeping with results obtained by Rudolph and coworkers (personal communication) who found that patients with a myocardial blood flow below 30 ml/min/100 gm had a life expectancy of less than 1 month. In the nonaffected myocardium, both in experiments with local complete ischemia and in experiments with infarction, the metabolic status was always within normal ranges. This is in contrast to results published by Gudbjarnason (1971/1972) and Gudbjarnason, Puri, and Mathes (1971), who found that in noninfarcted myocardium tissue levels of ATP and creatine phosphate decreased to about 50 percent of the control values and that there was no restoration to normal values within 10 days after infarction.

Adenosine Monophosphate↗