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The relation between pullulan synthesis and the different morphological types of the polymorphic microfungus Aureobasidium pullulans was investigated. Studies were performed under different culture conditions, aeration and agitation, and the extracellular polysaccharide production in cultures was then analysed. The results suggest that swollen cells and chlamydospores are the forms that produce extracellular polysaccharides. The hyphae do not play a role in extracellular polysaccharide synthesis.

Vitamin E (alpha-tocopherol) concentrations of plasma, platelets and erythrocytes were determined by HPLC in insulin-dependent (type I) and age-matched non-insulin-dependent (type II) diabetic patients and in two control groups. Plasma alpha-tocopherol levels were significantly increased in diabetic patients compared to control groups. Platelet and erythrocyte alpha-tocopherol levels were not significantly different in type I and type II diabetics as compared to their respective control groups, but differed from one another. Plasma vitamin E concentrations showed a significant correlation with plasma cholesterol and apoprotein B concentrations in different groups. The alpha-tocopherol/cholesterol and alpha-tocopherol/apoprotein B ratios in plasma were higher in diabetic patients, as were triglyceride contents. Platelet vitamin E levels were not significantly correlated with plasma concentrations. These findings suggest that vitamin E activity is altered in diabetic patients but that no diet supplementation seems necessary.

Two soluble forms of AChE from lymphocyte membrane have been obtained, the Triton solubilized Sd form and the high molar salt solubilized Ss form. They present similar Km (0.10 mM). Hydrodynamic properties of these forms have been studied on saccharose gradients with and without detergent or salt. A similar sedimentation coefficient has been found for these two forms (5.7 S). Lymphocyte plasma membrane AChE is a dimeric form (G2). Without detergent, the Sd form shows multiple secondary forms due to main form polymerization. Increase of NaCl concentration (2M) gives rise to a partial dissociation of these polymers. In the same conditions, the Ss form is not affected. The Ss form centrifugated on cesium chloride gradient has a higher density than the Sd form. These two forms have been treated by HPLC: the Stokes radii are respectively 7.1 nm for the Sd form and 4.5 nm for the Ss form. The molecular weights have been estimated at 175 000 for the Sd form and 105 000 for the Ss form. Pronase enzymatic digestion shows that the Ss form is more rapidly inactivated than the Sd form. Phospholipase C inhibits the Ss form and indicates that this form is a lipid-enzyme complex. The Sd form presents a different behaviour: this form is first activated, and afterwards inhibited by phospholipase C. This behaviour could be due to a more preponderant lipidic environment for the Sd form. The Sd form is probably a detergent-lipid-enzyme complex with an important hydrophobocity. These two forms can be explained by a different association between the enzyme and the phospholipids at the plasma membrane.