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Biomedical subjects

W Heller

Publications and source records attributed to W Heller.

At least 145 records · Page 8Linked to original sources

[Serum levels of magnesium and zinc after a controlled thermal trauma of the rat (author's transl)].

After a thermal trauma similar changes of Mg and Zn levels in serum are observable. During the initial period of shock the concentration of both elements increases as a consequence of damage of cellular and subcellular compartments. During the catabolic phase a deficiency syndrome occurs as a result of renal excretion, loss through the wound secretion, and demarcation of necrotic tissue. On the other hand increasing requirements of Mg and Zn appear because of the anabolic process of wound healing. From these reasons a substitution of both elements is recommendable in all cases of proved deficiency after burns.

Animals↗

[Selenium concentration and activity of glutathione peroxidase in lysate of human erythrocytes].

The concentration of selenium in human red cells was measured by a fluorometric determination method after wet digestion of the biological material. In the red cells from the same blood samples the activity of the selenoenzyem glutathione peroxidase (EC 1.11.1.9) was determined with tertiary butyl hydroperoxide as acceptor substrate. The results show that only 10% of the total selenium content of human red cells is fixed to the enzyme. No correlation between the enzyme activity and the selenium concentration could be found. On the basis of these results can be presumed that the protective effect of selenium in glutathione peroxidase against oxidant damage of cells is not the only biological function of this element.

Erythrocytes↗

[Studies on the stability of local anaesthetics containing adrenaline (author's transl)].

Local toxic reactions from adrenaline following nerve block anaesthesia have been observed by many workers. Because of this potential danger we studied the changes of anaesthetic solutions containing adrenaline during a longer storage period. The measurements show a drop in the pH of the solutions caused by decomposition of adrenaline. This effect of storage is not detectable with the naked eye but makes analytical procedures necessary. Molecular oxygen and light decompose the solutions rapidly. After a storage period of some months the acidity of the solutions is comparable to concentrated acetic acid, a fact which could lead to local complications.

Anesthetics, Local↗

[Changes in 2,3-diphosphoglycerate Levels in Blood and Brain Tissue after Craniocerebral Trauma and Cardiac Surgery].

The response of the 2,3-diphosphoglycerate (DPG) levels in the blood and brain tissue to a craniocerebral trauma of varying severity was studied in anaesthetized rats. A trauma producing cerebral contusion was followed within two hours by a highly significant rise in DPG concentration in the blood as compared with the control animals or only mildly traumatized rats. The DPG levels in the brain tissue showed no significant differences. Similar changes in DPG concentration were observed in the blood of patients with craniocerebral injuries. The DPG-mediated increased release of oxygen to the tissues represents a compensatory mechanism and is pathognomic for craniocerebral trauma. Patients undergoing surgery with extracorporeal circulation lack this mechanism for counteracting hypoxaemia; already during thoracotomy the DPG concentration in the blood fell significantly and did not reach its original level until 72 hours after the operation. In stored, ACD stabilized, blood the DPG concentration gradually decreases. Estimations carried out over 28 days showed a continuous statistically significant loss of DPG. After 24 hours the DPG levels in stored blood had already dropped to the lower limits of normal - a fact that has to be taken into account in massive blood transfusions.

Adult↗

Biochemical and biophysical changes in guinea pigs after acute head injury.

Animal experiments were set up mainly to derive additional diagnostic data from the study of biochemical changes after acute head injury. In standardized experiments guinea pigs were subjected in groups of 20 to three identical head injuries, each of either 1.0 J or 1.5 J intensity. The trauma was likely to result in a concussion or contusion syndrome similar to that found in man; 40 animals served as controls. During the 60 min after injury observation and measurement of body functions did not reveal signs of a shock-like condition or hypoxaemia in the traumatized animals compared with control animals. Superficial anaesthesia probably did not influence the findings. Temperature and respiration were altered significantly in all the animals receiving head injuries. Blood gas analysis showed a decrease of standard bicarbonate only after the 1.5 J injury but even though hypoxaemia was not present 2,3-diphosphoglycerate values and P50 increased, compared with the control animals. The fall of plasma lipid concentrations reported probably had to be seen as a sympathomimetic effect of the minor (1.0 J) trauma. Of special significance was the increased activity of malate dehydrogenase and aldolase, found only in the blood of severely traumatized animals, as this could serve as an early diagnostic aid for evaluating head injuries.

Alanine Transaminase↗