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Acetylation of methyl 6-O-trityl-α- D -glucopyranoside with one equivalent of acetic anhydride in pyridine yields, preferentially, the 4-acetate 8. The 2- and 3-acetates can be converted under mild alkaline conditions into 8, which is more stable towards acetyl migration.

Under controlled conditions, the possibility of recording from the epidural space a pressure higher than the pressure existing in the subdural space was reproduced. The phenomenon occurs when the epidural device records pressures deriving from a dural area larger than the area directly contacting the device. These results are obtained only when the epidural devices are shaped or placed in such a way to displace the surrounding dura from the bony face.

In 13 neurosurgical patients artificially ventilated with a N2O-O2 mixture, administration of 1 to 2 % of Ēthrane gene rally induced increases in intracranial pressure. The effect was negligible and sometimes absent in patients with normal intracranial pressure provided PaCO2 was lowered to hypocapnic levels. The effect was often marked, despite hypocapnia, in patients with high intracranial pressure associated with space-occupying cerebral lesions. This dangerous effect could be greatly attenuated if the intracranial fluid content and hence the pressure was previously reduced. The nature of these data as well as the place of the Ēthrane in neurosurgery are discussed.

The effects of general anesthetic drugs on intracranial pressure has been a frequent subject of research for some years, beginning with the pilot research by Woringer et al. [1, 2]. However, basic knowledge of their mechanism has only recently been obtained. Especially important are the data of McDowall and coworkers [3, 4, 5] on the direct vasodilatatory action of the volatile anesthetics on the cerebral circulation.

1. 1. Purified preparations of cattle liver lysosomal acid α-glucosidase (α- d -glucoside glucohydrolase, EC 3.2.1.20) are able to debranch glycogen and completely hydrolyze the polysaccharide to glucose by acting as an exoglucoamylase. The enzyme also completely hydrolyzes β-amylase limit dextrin to glucose. 2. 2. Glucose competitively inhibits the maltase activity of the α-glucosida 3. 3. The relationship existing between the catalytic centers binding maltose, isomaltose and glycogen of the cattle liver acid α- d -glucosidase was studied by means of kinetic experiments. As far as maltose and isomaltose are concerned, the present results suggest that the same center binds both substrates. The relationship between the catalytic centers binding maltose and glycogen seems to be rather complex. The data suggest that, in addition to the single catalytic site which binds both maltose and glycogen, the polysaccharide may require additional binding sites on the enzyme molecule.