[Prevention and rehabilitation of arterial peripheral circulatory disorders in the elderly].
Explore the source record for details and available documents.
Activities of Daily Living↗
Biomedical subjects
H G Schäfer
Publications and source records attributed to H G Schäfer.
[Awareness in total intravenous anesthesia].
After total intravenous anesthesia with propofol for suspension laryngoscopy the patient recalled intraoperative events. There were no obvious clinical signs during the supposed anesthetic course to warn the anesthetist that the fully relaxed patient might not be unconscious.
Adult↗
[An accidental intra-arterial injection of midazolam through a 3-way stopcock in an arterial flushing system].
Midazolam 5 mg (1 mg/ml) was accidentally injected intra-arterially into an intubated patient who was being transferred from the intensive care unit (ICU) to an operating room. No adverse effects were observed. To our knowledge, this is the first published case of intra-arterial administration of midazolam; whether this is generally harmless remains, therefore, an open question. Midazolam was injected through a 3-way stopcock in a manometer connecting tube. Three-way stopcocks in arterial lines are dangerous because of the risk of accidental intra-arterial injections. A careful preoperative check including the intravascular catheters is necessary in every patient, especially those being transferred from the ICU to an operating room.
Accidents↗
Anatomical re-evaluation of lumbar dura mater with regard to postspinal headache. Effect of dural puncture.
The effects of puncture of fresh cadaver dura with 20-, 22-, 26- and 29-gauge needles were observed. A 'tin-lid' phenomenon, manifested with all needle sizes, was capable of sealing the resultant hole. The larger the needle, the larger the hole, while rotation of the needle bevel 90 degrees to the fibres altered the shape of the hole. Holes made in thicker parts of the dura tended to retract more rapidly than those in thinner areas.
Anesthesia, Spinal↗
[Anesthetic data processing--the Bad Säckinger model].
A cost-effective computer program for district hospitals has been developed to process data from anesthetic charts. Apart from monthly and annual statistics relevant to clinical anesthesia and hospital administration, the described system allows free data handling of all material stored in the data base. The possibilities and limitations of electronic data processing are discussed.
Anesthesiology↗
Covalent fixation of NAD+ to dehydrogenases and properties of the modified enzymes.
Starting from 6-chloropurine riboside and NAD+, different reactive analogues of NAD+ have been obtained by introducing diazoniumaryl or aromatic imidoester groups via flexible spacers into the nonfunctional adenine moiety of the coenzyme. The analogues react with different amino-acid residues of dehydrogenases and form stable amidine or azobridges, respectively. After the formation of a ternary complex by the coenzyme, the enzyme and a pseudosubstrate, the reactive spacer is anchored in the vicinity of the active site. Thus, the coenzyme remains covalently attached to the protein even after decomposition of the complex. On addition of substrates the covalently bound coenzyme is converted to the dihydro-form. In enzymatic tests the modified dehydrogenases show 80-90% of the specific activity of the native enzymes, but they need remarkably higher concentrations of free NAD+ to achieve these values. The dihydro-coenzymes can be reoxidized by oxidizing agents like phenazine methosulfate or by a second enzyme system. Various systems for coenzyme regeneration were investigated; the modified enzymes were lactate dehydrogenase from pig heart and alcohol dehydrogenase from horse liver; the auxiliary enzymes were alcohol dehydrogenase from yeast and liver, lactate dehydrogenase from pig heart, glutamate dehydrogenase and alanine dehydrogenase. Lactate dehydrogenase from heart muscle is inhibited by pyruvate. With alanine dehydrogenase as the auxiliary enzyme, the coenzyme is regenerated and the reaction product, pyruvate, is removed. This system succeeds to convert lactate quantitatively to L-alanine. The thermostability of the binary enzyme systems indicates an interaction of covalently bound coenzymes with both dehydrogenases; both binding sites seem to compete for the coenzyme. The comparison of dehydrogenases with different degrees of modifications shows that product formation mainly depends on the amount of incorporated coenzyme.
Alanine Dehydrogenase↗