Seasonal and areal features of the lagoonal environment in Lake Nakanoumi,a shallow coastal lagoon in Japan

Lake Nakanoumi is a shallow coastal lagoon connected with the Japan Sea by a narrow channel. Over the past decade, land reclamation resulted in a 33% reduction of the lagoon's surface area. The remaining water basin of Lake Nakanoumi is scheduled to be artificially freshened to supply irrigation water for the newly reclaimed lands. This paper deals with the seasonal and areal features of the lagoonal environment prior to the beginning of the artificial desalinization.     

Unique T cell Ia antigen expressed on a hybrid cell line producing antigen-specific augmenting T cell factor

Hybrid cell lines were established by fusion between keyhole limpet hemocyanin(KLH) binding T cells of A/J mice and an AKR T cell tumor line, BW5147. Hybrids were selected for the presence of Ia antigen and KLH-specific augmenting activity of their extracts in the secondary antibody response. The detailed phenotypic and functional analysis of 1 of these clones, FL10, is reported here. The hybrid was positive for both Thy1.1 and Thy1.2 antigens and possessed the Lyt-1+,2-,3- phenotype. Both VH and Ia determinants were detected on their cell surface. The IA locus was mapped in the I-A subregion, but the Ia specificities were serologically distinct from those of B cell Ia antigen. This was demonstrated by the fact that anti-Ia antiserum preabsorbed with B cells could react with the hybrid cells, whereas none of the monoclonal anti-Ia specific for private and public determinations of Iak could. The extract from the cell line specifically augmented the in vitro secondary antibody response against dinitrophenylated KLH, and this activity was removed by absorption with antigen and conventional anti-Ia antisera. The results indicate that the cell line, FL10, carries Ia antigen unique to the T cell, which is associated with the antigen-specific augmenting molecule.     

Receptors for Dolichos biflorus agglutinin: New cell surface markers on a spontaneous leukemia

$\text{Dolichos biflorus}$ agglutinin (DBA), which is specific for terminal α-N-acetylgalactosamine, bound to a spontaneous leukemia cell of $\text{GRS}\text{A}$ mice, but not to lymphoid cells of the host. The DBA receptors were isolated from the leukemia cell labeled with [³H]-galactose after detergent solubilization and affinity chromatography on DBA-agarose. The major component of the receptors migrated as a glycoprotein of apparent molecular weight 100,000 upon SDS gel electrophoresis. Alkaline treatment degraded the glycoproteins, releasing oligosaccharides of molecular weight around 1,000.     

Three molecular forms of a rat asialoglycoprotein receptor

It has been reported that a rat asialoglycoprotein receptor is composed of three polypeptide chains with molecular masses of 43, 54, and 64 kilodaltons (43, 54, and 64-Kd forms) and that the first has a different primary structure from the latter two forms. Incorporation of [3H]leucine into these forms showed that no precursor-product relationship is found between the 54-Kd and 64-Kd forms. The half-life of the 43-Kd form (25 h) was shorter than those of the 54-Kd and 64-Kd forms (66 and 70 h, respectively). Glycopeptides of the three forms were prepared from rat livers previously labeled in vivo with [3H]glucosamine. Gel filtration analysis of the glycopeptides before and after endo H treatment revealed that they were all resistant to endo H. Alkali treatment did not change the elution position appreciately. These results indicate that the three molecular forms contained only complex oligosaccharide chains. The receptor was prepared from rat livers previously treated with tunicamycin in vivo and subjected to SDS-PAGE. A distinct band with a molecular mass of 33 Kd was observed. The receptor was also immunoprecipitated from rat hepatocytes in primary culture previously labeled with [35S]methionine and analysed by SDS-PAGE and fluorography. In addition to the major 43-Kd form, a band with a molecular mass of 41 Kd was found and tunicamycin treatment gave rise to a 33-Kd component, which is in good agreement with the receptor purified from tunicamycin treated rats. It is suggested that the 43-Kd form is synthesized as a 33 Kd polypeptide, cotranslationally glycosylated to form the 41 Kd component and then processed to the final 43-Kd form. We also think that the 43-Kd form could bind to asialoorosomucoid-Sepharose 4B without its carbohydrate chains.     

Sulfonamide-based non-alkyne LpxC inhibitors as Gram-negative antibacterial agents

We attempted to optimize sulfonamide-based non-alkyne LpxC inhibitors by focusing on improvements in enzyme inhibitory and antibacterial activity. It was discovered that inhibitors possessing 2-aryl benzofuran as a hydrophobe exhibited good activity. In particular, compound 21 displayed impressive antibacterial activity (E. coli MIC = 0.063 μg/mL, K. pneumoniae MIC = 0.5 μg/mL, and P. aeruginosa MIC = 0.5 μg/mL), and is a promising lead for further exploration as an antibacterial agent.     

Studies on the Foaming Property of the Chicken Egg White

The egg white was treated under various whipping conditions, and its foaminess measured. At the same time, the amounts of the coagulated proteins formed from each egg white and their constituent hexose were measured. From these results, discussions were made about the relation between the foaminess of the egg white and the amount of the coagulated proteins under various whipping conditions.