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The previously described temperature and pH-dependent transition in the solid state of hen lysozyme was studied in solution. Experiment concerning the velocity of lysis of M. luteus by lysozyme and its behavior in presence of an inhibitor (GlcNAc) as well as a reinvestigation of the Arrhenius curves over a large range of pH, demonstrated the existence of two temperature-induced domains. An inhibitor-insensitive lysozyme form was characterized at 40 degrees (physiological temperature).

From isoactivity curves (showing activity as a function of Ph and ionic strength) it was found that in the pH domain 6.7-8.6 frequently used in experiments involving hen lysozyme, the pH optimum of lysis of Micrococcus luteus cells at low ionic strength (0.02-0.05) by the high-temperature form (40 degree C, physiological temperature) was one to two pH units lower than that by the low-temperature form (20 degree C).

The binding of melittin to phospholipid bilayers and micelles depends on its quaternary structure and on the state of association of lipids. Monomeric melittin only binds to lipids above their cmc, whereas tetrameric melittin exhibits a biphasic binding; the interaction with monomeric lipids being possible without dissociation of the tetramer. In lipid excess, the bound state observed by fluorescence, polarization and ORD are always very similar. We propose the following model: the presence of a lipidic interface is necessary for the binding of monomeric melittin, while the tetramer may interact with lipid monomers without any dissociation: it might increase in size by addition of lipid molecules to form a micelle-like particle. The perturbations induced by melittin on the thermotropic behaviour of charged phospholipids are detected by calorimetry (DSC) and fluorescence polarization of DPH. For the first group of lipids, constituted of mono or divalent C14 and of divalent C16 lipids, the transitions are progressively abolished in the presence of melittin, without any shift of the temperature. For a second group of lipids, essentially constituted of monovalent C16 lipids, a cooperative transition is always observed. Moreover, at lipid to protein molar ratios higher than 8, there are two distinct well-defined transitions, at the same temperature as for pure lipid and 10 degrees C to 15 degrees C lower. All these results are interpreted by a phase separation occurring between quasi-pure lipid regions and the lipid-melittin complex. These last ones either could, or not, give rise to a phase transition, according to the cohesion of the initial bilayer. In the case of binary mixtures, there would be a phase separation between enriched phosphatidylcholine regions and negative lipid-melittin complexes.

The migration of lipiodol injected sub-occipitally (to obtain a lateral cervical myelogram) into the posterior fossa resulted in a unusual immediate neurological complication involving a major vegetative syndrome, facial hemispasm, excruciating pain in the left ear and, finally, epileptic loss of consciousness. The most likely aetiological hypotheses are acute changes provoked in the arachnoid mater by the substance or an arteria embolism.

Study on the asymmetry of the planum temporale by means of brain sections of 17 to 39 weeks old fetuses. There is a left predominance in 60 %, a right one in 25 % and symmetry in 15 % of the cases. Our results are similar to those published about adult brain, and cerebral dominance depends on it. Cerebral lateralisation is congenital and not acquired. There is also direct relation between the length of the lateral border of the planum temporale and its area. Such measure could be undertaken in living persons by means of radiological examination.

A study was made of the files 2292 patients examined by sacco-radiculography with watersoluble contrast medium, of whom 340 had been subjected to a second examination. 284 of these had undergone surgery with good results during the interval between the two examinations. In 56 cases, repeat sacco-radiculography was carried out but no operation performed. In both groups of patients a semiological study was made of the radiological appearances to determine which were the effects of the contrast medium and which could be attributed to the operation. The paper concludes with a discussion of the problem of genuine and false albuminoachies of sacco-radiculography using meglumine locarmate (dimer-X).