0000000000704096
AUTHOR
G. Erdmann
The Use of Polyols in Pediatrics
Children have a high demand of sugars or similar substances. These ought to be tolerable and easily utilized, furthermore palatable if given by mouth, and apt to supply a sufficient caloric intake. Often, carbohydrates are used as the only source of calories for ill children, e. g. in case of acute disturbances of the intestinal tract (caused by infection or incompatibility of food ingested, by malabsorption syndromes etc.) and in stress situations.
Therapie der Säure-Basen-Haushaltsstörungen im Kindesalter
Bei der Erorterung therapeutischer Bemuhungen um die Wiederherstellung eines geordneten Saure-Basen-Haushalts, womit wir uns nunmehr befassen wollen, darf ich die physiologischen Grundlagen als bekannt voraussetzen. Normalerweise herrscht eine ausgewogene Bilanz (Abb. 1 oben), was auch in der Puffergleichung mathematisch zum Ausdruck kommt. Dagegen treten grundsatzlich 4 verschiedene Moglichkeiten einer Bilanzstorung auf (vgl. Abb. 1 unten), die uberdies oft nicht in reiner Form, sondern kombiniert vorkommen. Bei Bestehen solcher Storungen, die jeweils auf Excess oder Defizit von Bicarbonat oder H2CO3 zuruckzufuhren sind, erfolgen pH-Veranderungen nach der Acidose oder Alkalose hin (vgl. Ta…
Activation and Inactivation of Tetanus Toxin in Chromaffin Cells
Tetanus toxin is produced by Clostridium tetani as a single chain, almost non-toxic, protein with a molecular weight of approximately 150.000 representing 1315 amino acids. Bacterial proteases cleave the molecule between positions A 457 and S 458 (extracellular activation), yielding a heavy chain (MW 100.000) and a light chain (MW 50.000) tetanus toxin (HC-TeTx, LC-TeTx). Both chains remain connected to each other by a disulphur bond between positions C 439 and C 467 (Dichain-TeTx)1. The cleavage or nicking dramatically increases the biological activity2. HC-TeTx is involved in binding DC-TeTx to gangliosides lodged in the plasma membrane, which is a prerequisite for incorporation into the …
Processing of tetanus and botulinum A neurotoxins in isolated chromaffin cells.
Tetanus and botulinum A neurotoxins were introduced into the cytosol of chromaffin cells by means of an electric field in which the plasma membrane is forced to form pores of approximately 1 micron at the sites facing the electrodes. As demonstrated by electron microscopy, both [125I] and gold-labelled tetanus toxin (TeTx) diffuse through these transient openings. Dichain-TeTx, with its light chain linked to the heavy chain by means of a disulfide bond, causes the block of exocytosis to develop more slowly than does the purified light chain. The disulfide bonds, which in both toxins hold the subunits together, were cleaved by the intrinsic thioredoxin-reductase system. Single chain TeTx, in…