Recent informations on the functional roles of plasma membrane phospholipids in two major blood cells, the erythrocytes and platelets, are described, including the following subjects ; 1) membrane lipid bilayer as a described, including the following subjects ; 2) asymmetric distribution of phospholipids in the membrane lipid bilayer, the mechanism of its maintenance and its physiological significances ; 3) participation of membrane lipid bilayer in the cell shape changes, and 4) regulatory actions of membrane lipids on the functions of membrane proteins, especially on the roles of membrane lipids and their metabolites in the transmembrane signal transduction system.

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Primary function of neutrophils is phagocytosis and killing of pathogenic microorganisms, and oxygen metabolites are known as principal microbicidal factor in neutrophils. However, oxygen metabolites are often toxic to living body, since they are too reactive to cause inflammation, cancer, aging, etc. It has been indicated that NADPH oxidase associated with plasma membranes is responsible for the production of superoxide anion (O-2), which is followed by the production of other toxic active oxygens such as hydrogen peroxide, hydroxyl radical and singlet oxygen. On phagocytosis or by exposure to certain stimuli, NADPH oxidase is activated from the dormant state. But, the biochemical mechanism for the activation of NADPH oxidase has not been fully clarified, recent intensive studies using cell-free activation systems and neutrophils from patients with chronic granulomatous disease (CGD), in which O-2production is genetically deficient, showed that NADPH oxidase on the plasma membrane consists of many components existing not only in the plasma membrane but also in the cytosol. We found that phosphorylation of 48K protein (s) was increased in human neutrophils in parallel with the activation of NADPH oxidase after the treatment with PMA, a protein kinase C activator, and that the 48K protein phosphorylation was deficient or abnormal in many types of CGD neutrophils. In this paper, we review the activation mechanism with special references to the assembly of the components of NADPH oxidase on the plasma membranes.

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In order to understand quantitatively both the macroscopic and the microscopic behavior of blood, we have attempted to review three main areas of red blood cell (RBC) rheology based on our recent work : 1) the macroscopic flow behavior of RBCs, i. e., viscosity and pressure-flow rate relationships of RBC suspension; 2) the microrheological behavior of RBCs, i. e., RBC deformability; 3) a role of membrane cytoskeleton in microrheological properties of RBCs. Especially, we presented a new quantitative filtration method using a newly developed thin metal film with pores (the nickel mesh), and demonstrated a close link between decreased deformability of RBCs and fragmentation of membrane cytoskeletal proteins including a role of hemoglobin in it. Although the present review is limited in both breadth and depth, it may contribute to provide a new insight into RBC rheology.

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Immunoglobulin G (IgG), complement (C₃b) and fibronectin (FN) in plasma enhanced the phagocytosis of anionic and hydrophobic particles by granulocytes. Fibrinogen in plasma suppressed the phagocytosis cationic and hydrophobic particles. The phagocytosis of hydrophilic carboxylated particles with highly negative charges were enhanced by C₃b in plasma. Granulocytes recognized the particles through their membrane receptors (Fc, C₃b and FN). The degree of phagocytosis in plasma was attributed to the protein absorption from plasma on particles, and the adsorption behaviors such as species, amounts, orientation, and conformational change of proteins were depended on their surface properties of particles. The morphology of the granulocytes varied according to the size of particles. The particles with a diameter less than 7μm were able to be phagocytosed by granulocytes, and 10-20μm particles were covered with many spreading granulocytes. Intracellular microfilament and microtubule and metabolic energy played an important roles in phagocytosis of particles by granulocytes, judging from the results using various inhibitors.

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An actual municipal wastewater was used as the feed solution, reverse osmotic concentration of multicomponent solutes was carried out using four types of composite membranes. The experimental results were compared with the experimental results of single solute-water binary systems and discussed how to estimate the solute rejections of a membrane for i species in a multicomponent system using the experimental data obtained from only i species-water binary system.

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The biophysical characteristics of microcapsule membranes are described Thus, the methods of preparing water-loaded microcapsules are given first, and then the permeability of the microcapsules towards solutes is discussed as a function of microcapsule size. The distribution of fixed charges in microcapsule membranes is determined from their electrophoretic mobilities at different pH and ionic strengths. The disintegration phenomenon of microcapsule membranes caused by the action of fibrous proteins and some practical applications of microcapsules in biotechnology are also mentioned.

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