A New Species of Poorly Known Mayfly Genus Paegniodes Eaton (Ephemeroptera: Heptageniidae) from Vietnam

A heptageniid mayfly species Paegniodes dao sp. nov. (Ephemeroptera: Heptageniidae) is described from Vietnam. The larva is distinguished by round anterolateral margins of pronotum, triangular‐shaped labrum, rudimentary lamella and well developed fibrillae of gills 1, and light brown body that lacks distinct markings. Diagnosis, line drawings, material, and habitat data are provided.     

Induction of interdigitating reticulum cell-like differentiation in human monocytic leukemia cells by conditioned medium from IL-2-stimulated helper T-cells

Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features. Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned medium significantly down-regulated the expression of CD14 antigen. Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is necessary for the differentiation and maturation of IDC.     

Recycling of membrane proteins during endo- and exocytosis in amoebae

The fate of a membrane protein of the amoeba plasmalemma was studied by means of 125I iodination by lactoperoxidase, gel electrophoresis, radioautography and gamma counting. There was only one iodinatable polypeptide group with a molecular weight (MW) of 175 000 on the external surface of the plasmalemma. Two hours or more after induced phagocytosis, isolated phagolysosomal membranes contained two other smaller polypeptides with MWs of 70 000 and 35 000, respectively, suggesting that the 175 000 polypeptide was broken down to these smaller components during endocytosis. After 22 h of induced phagocytosis, isolated plasmalemma contained a 35 000 polypeptide group in addition to the 175 000 polypeptide species. The results suggested that some of the iodinatable membrane proteins were altered and recycled during endo- and exocytosis in amoebae, while others were recycled intact.     

Pilot-scale production of l-phenylalanine from d-glucose

Effects of inoculum size and total sugar content on both l-phenylalanine productivity and titre have been investigated using a tyrosine auxotrophic regulatory mutant of Escherichia coli. Fermentations were carried out in a 500 litre pilot fermenter with intermittent feeding of d-glucose plus phosphate. It was found that the productivity was not greatly affected by inoculum size. However, the l-phenylalanine titre was significantly affected by total sugar content. Relatively high productivities of up to 0.35–0.40 g l-phenylalanine l^?1 h^?1 have been achieved at l-phenylalanine titres of 14–15 g l^?1.     

Kinetics of producing pro-urokinase in perfusion cultivations

Summary Better production of pro-urokinase from human cell line was observed with 5% serum containing medium than 10% or serum free medium on Cytodex II under perfusion chemostat operations, showing 0.8×10^–5 (IU/daycell) of maximum productivity at 0.020 (l/h) of dilution rate in 5% serum medium, which corresponds to 800 IU/mL at this dilution rate. Conversion of pro-urokinase was reduced in the serum-containing media.     

Production of high fructo-oligosaccharide syrup with two enzyme system of fructosyltransferase and glucose oxidase

Summary A novel two enzyme system of fructosyltransferase and glucose oxidase to enhance the content of the net fructo—oligosaccharide (FOS) fractions in the industrial production of FOS syrup from sucrose was devised. The net FOS content in the commercial FOS syrup has been limited only to 55–60 % due to the accumulation of glucose which acts as a feedback inhibitor of the fructosyltransferase. By supplementing glucose oxidase to the conventional FOS reaction system, we could convert the glucose to gluconic acid readily separable from neutral sugars by simple ion exchange operation in the next step. The simultaneous removal of glucose was proved effective in proceeding the reaction by fructosyltransferase further by relieving the product inhibition caused by glucose. By this way, we could raise the net FOS content as high as 90 %.