Biophysical and biochemical alterations in erythrocyte membranes from chronic alcoholics.

Erythrocyte membranes from healthy controls and alcoholic patients, examined within 24 h of abstinence, were studied for basal membrane fluidity and membrane sensitivity to ethanol by fluorescence polarization of the apolar probe 1,6-diphenyl-1, 3,5-hexatriene (DPH) and its cationic derivative 1,4(trimethylammonium phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). The membrane partition (Kp) of ethanol and phenobarbital, and the concentrations of membrane-bound sialic acid and galactose, were also determined. The apolar hydrocarbon region of the membrane (DPH) was less fluid, in the alcoholics than in the controls (p less than 0.005). In the patients this membrane layer, as well as the polar lipid head group region (TMA-DPH), showed reduced fluidizing effect of ethanol (p less than 0.01). This resistance or tolerance to ethanol correlated with a markedly impaired (-59%, p less than 0.025) partition of ethanol into the membrane. The low Kp of ethanol in turn was partly related to reduced concentrations of polar carbohydrates such as sialic acid and galactose (p less than 0.01) at the membrane surface. The Kp of phenobarbital was reduced in the patients (-59%, p less than 0.005) but, apparently unrelated to the carbohydrate changes. These results indicate that in man, chronic alcohol abuse is associated with complex changes of membrane properties at different membrane levels e.g. at the charged surface, in the polar lipid head group region and in the hydrocarbon core. A partial basis for biophysical membrane tolerance to ethanol is suggested, implying that apart from phospholipid alterations, structural changes in membrane-bound glycoconjugates participate in this adaptive process.

[Computerized processing, using a Macintosh, of ambulatory arterial pressure measurements collected on a Spacelabs monitor]. / Traitement informatisé sur Macintosh des mesures de pression artérielle ambulatoires recueillies sur moniteur Spacelabs.

UNLABELLED: The use of the Spacelabs blood pressure recorder has given rise to processing programs running on Apple II and IBM PC computers. The authors have written in M.S. BASIC (2.1) a program who take advantage of graphic abilities and easy manipulation on Macintosh. The software was designed to perform three tasks: Communicating between Macintosh and Spacelabs station using serial interface (RS 232) without requesting specific interface card. Editing a report on two pages: The first is the listing of 96 measurements (one by 15 minutes). The second provides: patient identification, height, weight, diagnosis. Graphic representation of measurements Systolic and diastolic blood pressure (BP) repartition histogram for 24 hours, day and night. Standard deviation and mean of pressure and heart rate (HR) for those periods. A third optionally gives hourly chronogram and diagrams for cumulated BP and HR. Creating a file: 550 records can be stored on a 800 K floppy disk. The file handles: data for each patient (excepted identification). Random access and revision of each parameter is possible. SYNTHESIS: comparative reports for group patients and patient by patient analysing data with appropriate statistical test (ANOVA and correlation) are done.

Membrane properties in behaviorally ethanol-dependent rats.

A way of quantifying alcohol behavioral dependence in rats previously developed was used in the present study to get more insight into the relations between neuronal membrane "fluidity", degree of dependence and membrane "sensitivity" (ethanol partitioning and disordering capacities).