Appearance of a Cell Surface Antigen Associated with the Activation of Peritoneal Macrophages in Mice

A relatively large population of murine peritoneal exudate macrophages induced with viable BCG or heat-killed Corynebacterium parvum was stained by the antiserum prepared against purified gangliotetraosyl ceramide (asialo GM1), while only a small population of peritoneal resident macrophages or peritoneal exudate macrophages induced with proteose peptone was stained. The cytotoxicity assay of those macrophages with anti-asialo GM1 plus complement supported these results. Peritoneal macrophages induced with BCG or C. parvum showed strong cytotoxicity for EL4 cells in vitro, while resident or peptone-induced peritoneal macrophages showed no cytotoxicity. BCG- or C. parvum-induced peritoneal cells contained both NK cells and cytotoxic macrophages, and either in vivo or in vitro pretreatment of the cells with anti-asialo GM1 and complement abolished the activities of both types of cells. Peptone-induced peritoneal macrophages incubated with lymphokines (LK) or lipopolysaccharide (LPS) were cytotoxic for EL4 cells and contained an increased number of cells stained by anti-asialo GM1. The cytotoxicity of these in vitro activated macrophages was reduced by treatment with anti-asialo GM1 plus complement. When peptone-induced peritoneal macrophages were incubated with LK, the number of cells stained by anti-Ia antiserum increased, but the number did not increase when the macrophages were incubated with LPS. Pretreatment of peptone-induced macrophages with anti-asialo GM1 plus complement did not affect the ability of the macrophages to be activated by LK. These results taken together strongly suggest that the antigen (s) reactive with anti-asialo GM1 is expressed on the cell surface of cytotoxic peritoneal macrophages in mice.     

Effects of winter flooding on phosphorus dynamics in rice fields

Limnology - Controlling phosphorous (P) loads from rice fields is important for the conservation of aquatic ecosystems, in part because P is relatively concentrated at its sources. Recently, winter...     

Effect of a high-protein diet on the gene expression of a trypsin-sensitive, cholecystokinin-releasing peptide (monitor peptide) in the pancreas

The adaptation to a high protein diet of the concentration and mRNA level of a trypsin-sensitive, cholecystokinin-releasing peptide (monitor peptide), which was proposed to be the mediator of the cholecystokinin release in response to protein intake, was investigated in the rat pancreas. Adult rats were placed on one of two isocaloric diets. One group was fed a 22% casein diet (control diet) and the other a 64% casein diet (high-protein diet) for 14 days. In order to quantify the monitor peptide separately from pancreatic secretory trypsin inhibitor (PSTI-II), which is highly similar in its amino acid and mRNA nucleotide sequences to the monitor peptide but has less cholecystokinin-releasing activity, we used specific assay methods: HPLC was used for determining the monitor peptide concentration in zymogen granules and a synthetic oligonucleotide probe for determining the mRNA of the monitor peptide in the pancreas. The concentrations in the zymogen granules and the mRNA levels in the pancreas of the two peptides increased in parallel during the adaptation to the high protein diet, indicating that these two peptides were under the same control during the adaptation. The concentration and mRNA level of the monitor peptide, which were measured after 0, 3, and 14 days, increased throughout the experiment period, as did the concentration of trypsin. This suggested that the monitor peptide and trypsin may respond to similar signals during the adaptation to a high protein diet and that this apparent coordination may facilitate the adaptation of the pancreas to the diet.     

In addition to the ARS core, the ARS box is necessary for autonomously replicating sequences

Summary Autonomously replicating sequences (ARSs) were cloned from nuclear and mitochondrial DNA of D. melanogaster using YIp5, which is composed of pBR322 and the yeast ura3 gene, as the cloning vector and YNN27, a Ura^- yeast strain as the recipient. The nucleotide sequences of six ARSs, two from nuclear bulk, two from the nuclear 1.688 satellite, and two from mitochondorial DNA, were determined. The relationship between the transformation frequency and the inclusion of the ARS core, 5 _T ^A TT-TAT _A ^G TTT _T ^A 3, of these fragments was analysed. All the ARSs contained an ARS core or a single base change of it. However, not all the fragments that contained a single base change of the ARS core were able to transform the recipient cells, suggesting that certain bases in the ARS core were not exchangeable. It is suggested by transformation experiments with subfragments that in addition to an ARS core, an ARS box which is located within 25 bp upstream of the ARS core and whose sequence is composed of 5TNT _G ^A AA 3, is necessary for autonomous replication.     

Diverse effects of insulin-induced hyperpolarization on 3-O-methyl-D-glucose (3-O-MG) transport in frog skeletal muscles

It has been suggested that the insulin-induced hyperpolarization might be a mediator of the stimulatory action of insulin on glucose transport. The purpose of the present study was to investigate the relationship between the insulin-induced hyperpolarization and the stimulatory action of insulin on glucose transport in skeletal muscle. Satorius muscles dissected from bullfrogs (Rana catesbeiana) were used. Insulin induced a hyperpolarization of the membrane and an increase in the 3-O-Methyl-D-glucose (3-O-MG) uptake and extrusion. In the presence of valinomycin, insulin had no significant effect on the membrane potential. Insulin still had the stimulatory action on both the 3-O-MG uptake and extrusion even in the presence of valinomycin, under whose condition insulin had no significant effect on the membrane potential. The magnitude of the stimulatory action of insulin on the 3-O-MG uptake in the presence of valinomycin was smaller than that in the absence of valinomycin. The magnitude of the stimulatory action of insulin on the 3-O-MG extrusion was, on the contrary, larger than that in the absence of valinomycin. The abolishment of the insulin-induced hyperpolarization decreased the 3-O-MG uptake and increased the 3-O-MG extrusion. The observation in the present study concludes that insulin has two different actions on glucose transport. One of them is developed through the insulin-induced hyperpolarization, which increases the 3-O-MG uptake and decreases the 3-O-MG extrusion. The other action is irrelevant of the insulin-induced hyperpolarization and stimulates both the 3-O-MG uptake and extrusion.     

Mutations in {beta}-Tubulin Block Transhyphal Migration of Nuclei in Dikaryosis in the Homobasidiomycete Coprinus cinereus

ß-Tubulins from fourteen benomyl-resistant strainsof the homobasidiomycete Coprinus cinereus, which carry thebenA, benB, benC or benD mutations, were analyzed by urea SDS-PAGEor isoelectric focusing and subsequent immunoblot analysis.Electrophoretic aberrations in a major ß-tubulin isotype,denoted ß1 were found in two strains, BEN154 and BEN215,both of which carry benomyl resistance mutations in benA ⁺ Theaberrations of ß1 in BEN154 and BEN215 cosegregatedwith benomyl resistance among the progeny of outcrosses of BEN154 and BEN215 to wild type, indicating that the ß1aberrations were caused by the benA mutations. Both the mutantand wild-type ß1 tubulins were present in the heterozygousdikaryons, BEN 154/wild-type and BEN215/wild-type, ruling outpost-translational modification as a possible cause for theaberrations in ß1. Thus, we conclude that benA isa structural gene for ß1. Transhyphal migration ofnuclei in dikaryosis was blocked in the mycelia of BEN 154 andin its progeny that carried benA (ß1 mutation), demonstratingthat microtubules are involved in the migration process. Nuclearmigration in dikaryosis seems to differ in terms of mechanism,at least in part, from the migration of tetrad nuclei from basidiainto prespores during formation of basidiospores and from themigration of nuclei from basidiospores into hyphae during germination,because a benA mutation blocked the former without affectingthe latter two processes. (Received May 19, 1989; Accepted August 30, 1989)     

CD16+ lymphoblastic cell lines of crab-eating monkeys (Macaca fascicularis) shared U-5 antigen and expressed natural killer activity

The CD16+ lymphoblastic cell lines of crab-eating monkeys shared the U-5 antigen recognized by a monoclonal antibody. The CD16+U-5+ cell lines expressed high natural killer activity to K562 cells, whereas the CD16-U-5- control cell line had no significant natural killer activity. A possible involvement of the U-5 antigen in natural killer function was also suggested by reduction of the natural killer activity in peripheral blood mononuclear cells of Japanese monkeys after treatment with U-5 monoclonal antibody and complement.     

Development of a series of monoclonal antibodies recognizing leukocyte differentiation antigens of Japanese monkeys (Macaca fuscata)

Six monoclonal antibodies to Japanese monkey leukocytes were developed. These monoclonal antibodies, designated the U series, cover most kinds of leukocytes (pan T cells, CD8+ cells, CD8+ subset and granulocytes, CD16+ cells, monocytes/macrophages), and should be useful in the immunological analysis of primate models, such as tissue transplants and virus-related diseases, in particular, acquired immune deficiency syndrome (AIDS).