A photochemical fuel cell system using Anabaena N-7363

Summary A blue-green algae, Anabaena N-7363, was immobilized in 2% agar gel. The hydrogen productivity of the immobilized algae was three times higher than that of free algae. The maximum hydrogen production rate by the immobilized blue-green algae was 0.52 moles h^–1 g^–1 (of wet gel) in the medium without nitrogen sources under illumination (10,000 lux). The oxygen evolved was then removed by a reactor containing aerobic bacteria. A photo-current of 15–20 mA was continuously produced for 7 days by the photochemical fuel cell system consisting of the immobilized Anabaena reactor, the oxygen-removing reactor and the hydrogen-oxygen fuel cell. The conversion ratio of hydrogen to current was from 80% to 100%.     

Bovine virus diarrhea-mucosal disease. II. Isolation and characterization of a cytopathogenic virus and experimental production of the disease.

A disease broke out in calves in the Tokachi district of Hokkaido. It induced pyrexia, respiratory symptoms, diarrhea, bloody feces, leukopenia, and sometimes erosion of the oral mucous membrane and muzzle. Its morbidity rate was 90% and its fatality rate 50%. Bovine virus diarrhea (BVD) virus was isolated from organs of dead calves and blood and feces of affected calves. It exhibited a cytopathic effect on calf kidney cell culture. Antisera against the Nose and the Oregon C24V strains of BVD virus showed an antibody titer of the same order against the homologous virus and the isolated strain. Antiserum against the isolated strain, however, showed much lower antibody titers against the Nose and the Oregon C24V strains than against the homologous virus. When inoculated with the isolated virus, two calves manifested acute symptoms, but recovered at any rate. One of them, however, suffered again from clinical infection and died eventually 37 days after inoculation. It presented pathological changes closely resembling those of the case of spontaneous infection. Virus was recovered from its principal organs, intestinal canal, and lymph nodes of various regions of the body.     

Infrared analysis of pea stem cell walls and oriented structure of matrix polysaccharides in them

Infrared absorption spectra of film specimens of the epidermaland parenchyma cell walls of the third internode of pea stem,before and after protease treatment and after treatment forremoval of lipid materials, pectic substances and hemicellulose,were recorded, and characteristic bands in the spectrum of thewall were assigned. Polarization spectrum measurements of thewall provided evidence indicating that the non-cellulosic polysaccharidematrix as well as cellulose microfibrils has an oriented structurein the wall which changes during extension growth as well asupon mechanical extension of the walls. (Received March 9, 1978; )     

Effect of auxin on changes in the oriented structure of wall polysaccharides in response to mechanical extension in oat coleoptile cell walls

The increase in the dichroism of the ester-C=O and COO^–bands in response to mechanical extension in oat coleoptilecell walls was much enhanced by IAA pretreatment while the decreasein that of the C-O-C band was not enhanced or even suppressed.The results indicate the importance of the ultrastructure ofnon-cellulosic polysaccharides in controlling auxin-inducedcell elongation. ¹ Present adress: Department of Agricultural Chemistry, KyotoPrefectural University, Shimogamo, Kyoto 606, Japan. (Received May 16, 1978; )     

Use of tritiated 3-O-methyl-d-glucose for studies of membrane transport caveat

Tritiated 3-O-methyl-d-glucose has many useful attributes as a model substance for studies of the transport of glucose across cell membranes. However, preparations of high specific radioactivity can decompose within a few months, producing radioactive impurities that can cause a several-fold increase in the apparent rate of sugar transport. In our investigation radioactive contaminants entered frog skeletal muscle cells by free diffusion rather than by facilitated transport. Much of the contaminating radioactive material could be removed by evaporating the solvent and redissolving the sugar. Tritiated sugar samples that had a specific activity below 0.1 Ci/mmol remained stable and suitable for transport measurements after several years of storage at -20°C. In order to evaluate the suitability of a given tritiated preparation of sugar for transport measurements, it is recommended that its behavior be compared with that of a stable reference standard of low specific activity.     

Effect of dextran sulfate on the interaction between very low density lipoprotein and lipoprotein lipase

The effect of dextran sulfate on the interaction between very low density lipoprotein (VLDL) and purified bovine milk lipoprotein was studied. Dextran sulfate increased VLDL-triacylglycerol hydrolysis by lipoprotein lipase about 2-fold, but did not alter the Km value for triacylglycerol in VLDL. Strong association of dextran sulfate with the VLDL-lipoprotein lipase complex was demonstrated by gel filtration on BioGel A-5m, although dextran sulfate did not bind to VLDL and only very slightly to lipoprotein lipase. These findings suggest that dextran sulfate increases triacylglycerol hydrolysis in VLDL by binding to the VLDL-lipoprotein lipase complex.     

Further characterization of the autologous mixed lymphocyte reaction: induction of double negative gamma delta T lymphocytes.

To investigate the specific nature of the autologous mixed lymphocyte reaction (AMLR), we applied a method in which mixtures of NY-nonadherent responder cells and NY-adherent stimulator cells were treated with neuraminidase before culture and then cultured to assay the AMLR. This method produced a marked enhancement of DNA replication in the responder cells and the results were reproducible, regardless of the individuals tested. Using this method, we were able to make the following observations regarding the specific nature of the AMLR. (i) The AMLR is an IL-2-independent reaction, as revealed by bioassay to detect the presence of IL-2 by a blocking test using anti-IL-2R sera and as shown by the absence of mRNA for IL-2 in Northern hybridization. (ii) It is also HLA-DR dependent as proven by the fact that anti-DR sera almost completely inhibited the reaction. (iii) The AMLR was also found to induce the generation of activated CD4+ helper T cells in direct response to stimulation by NY-adherent cells, in which HLA-DR antigens were involved. (iv) Also, it induced the generation of CD4-CD8- double-negative (DN) lymphocytes, including gamma delta T cells with a cytotoxic activity against NK-resistant target cells and with a variety of lymphocyte activation markers (CD56, HLA-DR, CD25, transferrin receptors, CD38, and LFA-1). However, the AMLR did not induce the generation of NK cell markers CD16 and CD57. (v) The DN lymphocytes and gamma delta T cells appeared to be generated from the precursors of CD4-CD8- DN cells, in direct response to the stimulator cells. These results strongly suggest that the AMLR may be a phenomenon which induces the proliferative response of gamma delta T cells and their precursors, in addition to that of alpha beta T cells, particularly of CD4+ helper T cells.     

A protease inhibitor produced by Streptomyces lividans 66 exhibits inhibitory activities toward both subtilisin BPN' and trypsin.

A proteinaceous protease inhibitor was isolated from the culture broth of Streptomyces lividans 66 by a series of purification steps (salting out by ammonium sulfate, ion-exchange chromatography on DEAE-cellulose, hydrophobic chromatography on Phenyl-Sepharose, and gel-filtration on Sephacryl S-200), and was named S. lividans protease inhibitor (SLPI). The purified SLPI existed in a dimeric form consisting of two identical subunits, each of which was composed of 107 amino acids. SLPI exhibited strong inhibitory activity toward subtilisin BPN'. These features were similar to those of protein protease inhibitors produced by other Streptomyces (SSI family inhibitor). In addition, SLPI was capable of inhibiting trypsin with an inhibitor constant (Ki) of about 10(-9) M. The primary structure of SLPI and location of two disulfide bridges were homologous to those of the other serine protease inhibitors of Streptomyces. The reactive site of SLPI was found to be Arg67-Glu68 from the sequence analysis of cleaved SLPI which was produced by acidification of subtilisin-SLPI complex. An Arg residue at the P1 site was consistent with the trypsin-inhibitory property of SLPI. Sequence comparison with other members of the SSI family revealed that amino acid replacements in SLPI were mainly localized on the surface of the SLPI molecule, and many of the amino acid residues in beta-sheets and hydrophobic core were well conserved.     

Purification and characterization of membrane-bound endoglycoceramidase from Corynebacterium sp.

Endoglycoceramidase catalyzes the hydrolysis of the linkage between oligosaccharides and ceramides of various glycosphingolipids. We found that a bacterial strain Corynebacterium sp., isolated from soil, produced endoglycoceramidase both intracellularly and extracellularly. The intracellular enzyme bound to the cell membrane was solubilized with 1% Triton X-100 and purified to homogeneity about 170-fold with 60% recovery. The molecular mass of the enzyme was approximately 65 kDa. The enzyme is most active at pH 5.5-6.5 and stable at pH 3.5-8.0. Various neutral and acidic glycosphingolipids were hydrolyzed by the enzyme in the presence of 0.1% Triton X-100. Ganglio- and lacto-type glycosphingolipids were readily hydrolyzed, but globo-type glycosphingolipids were hydrolyzed slowly.