Biomedical subjects

T Komuro

Publications and source records attributed to T Komuro.

At least 91 records · Page 5Linked to original sources

PubMed1989

Enkephalin-binding protein in human blood.

An enkephalin-binding protein was found in human plasma and serum. The protein was partially purified by DEAE-cellulose column chromatography. The binding of [3H]leucine-enkephalin to this protein was competitively inhibited by unlabeled leucine- and methionine-enkephalin and various peptide hormones such as beta-endorphin and glucagon, but not by Leu-enkephalin-amide. The fact that amide derivatives of leucine-enkephalin and methionine-enkephalin did not inhibit the binding suggests that c-terminuses of enkephalins might have an important part in binding the protein. From these results, physiological roles of the enkephalin-binding protein are discussed.

Binding, Competitive↗

PubMed1988

Analysis of Salmonella lipopolysaccharides by sodium deoxycholate-polyacrylamide gel electrophoresis.

Lipopolysaccharides (LPSs) were analyzed by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium deoxycholate (DOC) or sodium dodecyl sulphate (SDS) and the results obtained compared. Two-dimensional PAGE of the S form of LPS revealed that, with SDS, bands which appeared to be single after the one-dimensional experiment were resolved into several bands after two-dimensional electrophoresis. In the presence of DOC, however, a diagonal of single bands was obtained in one-dimensional electrophoresis indicating optimum resolution. The high quality of resolution by DOC-PAGE was constant for amounts of LPS up to 20 micrograms. Finally, DOC-PAGE does not require boiling of the samples in DOC, which may be an advantage over SDS-PAGE.

Deoxycholic Acid↗

PubMed1988

Direct contacts between Auerbach's ganglia and smooth muscle cells in the small intestine of the rat.

The present electron microscopic study demonstrated direct contacts between Auerbach's ganglia and longitudinal smooth muscle cells in the rat small intestine. The muscle cells were often observed to extend small, foot-like processes to the Auerbach's ganglia. These processes were in contact with glial cells in the ganglia without an intervening basal lamina, or were in contact with intraganglionic axon varicosities containing many synaptic vesicles. The processes in contact with glial cells may anchor the muscle cells to the ganglia during muscle contraction and those in contact with axon varicosities may function as synaptic sites between ganglion and longitudinal muscle cells.

Animals↗

PubMed1988

Structural requirements of lipid A species in activation of clotting enzymes from the horseshoe crab, and the human complement cascade.

The structure/activity relationship of lipid A, a bioactive center of endotoxic lipopolysaccharides, in the activation of the clotting enzyme cascade of a horseshoe crab amoebocyte lysate (Limulus activity) and the complement system in human serum, was examined using synthetic lipids A and related compounds. Regarding Limulus activity, a newly developed colorimetric method, which utilizes a mixture of recombined clotting factors and a chromogenic substance, was much more sensitive for detecting changes in the chemical structure of test compounds than the conventional gelation method using the amoebocyte whole lysate. (beta 1-6)-D-Glucosamine disaccharide bisphosphates, which had neither 3-hydroxyacyl nor 3-acyloxyacyl groups, and acylglucosamine phosphates, which in structure correspond or are analogous to the non-reducing or reducing moieties of lipids A and biosynthetic disaccharide lipid A precursors showed only negligible activity in the colorimetric tests, but they exhibited a distinct though much weaker gelation activity than the parent disaccharide molecules. The assay results obtained by the colorimetric Limulus test correlate better with the pyrogenicity of the test synthetic compounds than those given by the gelation method, although the dependence of pyrogenicity on chemical structure is greater. The presence of 3-hydroxyacyl groups on the bisphosphorylated (beta 1-6)-D-glucosamine disaccharide backbone is the prerequisite for effective activation of the clotting enzyme cascade of horseshoe crab amoebocyte lysate, while the presence of an adequate number (one or two) of 3-acyloxyacyl groups on the disaccharide bisphosphate backbone is needed for full pyrogenicity. Complement activation, on the other hand, showed structural requirements quite different from those for the colorimetric Limulus activity and the pyrogenicity. The disaccharide compounds that had only non-hydroxylated acyl groups, acylated glucosamine phosphates that had the structure of the non-reducing portion of lipids A and biosynthetic disaccharide precursors, which were scarcely active in the colorimetric Limulus test, caused complement activation comparable to or sometimes stronger than that of the parent disaccharide molecules. Acylglucosamine phosphates, corresponding in structure to the reducing moiety of disaccharide compounds, however, showed little activity.

Animals↗

PubMed1988

Large-scale fractionation of S-form lipopolysaccharide from Salmonella abortus equi. Chemical and serological characterization of the fractions.

The S-form lipopolysaccharide of Salmonella abortus equi was separated by a newly elaborated extraction method with organic solvents into three fractions of different chain length of the O-polysaccharide they contained. The three fractions were designated long-chain (20-50 repeating units), short-chain (0-6) and R-fraction (no repeating units) according to their migration pattern in polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate. The nature of the fractions as long- and short-chain and as R-fraction was confirmed by chemical analysis. The concentration of O-specific sugars was highest in the long-chain fraction, where their molar ratio to glucosamine was ca. 25:1. In the short-chain fraction the ratio of O-sugars to glucosamine was 2.5:1, and in the R-fraction O-specific sugars were absent. The serological properties of the three fractions were in good agreement with their chemical composition.

Carbohydrates↗

PubMed1988

The lattice arrangement of the collagen fibres in the submucosa of the rat small intestine: scanning electron microscopy.

The three-dimensional architecture of the submucosal collagen fibres of the rat (3 weeks old) small intestine was examined by scanning electron microscopy using a selective microdissection method. The main framework of the submucosa was composed of two arrays of collagen fibre bundles running diagonally around the intestinal wall, one set in a clockwise direction, the other counterclockwise. These fibre bundles were about 5 micron diameter and were oriented at a range of angle +/- 30 degrees -50 degrees to the longitudinal axis of the intestine. With the advantage of the SEM observation it was demonstrated that these fibres in different arrays did not constitute two separate layers but interwove to form a unified lattice sheet. An irregular network of fine collagen fibrils over the main framework was also seen. The significance of their arrangement is discussed with respect to the skeletal function of the submucosa in the intestine.

Animals↗

PubMed1988

Close relationships between the cells of the immune system and the epithelial cells in the rat small intestine.

A possible contribution of the intestinal epithelium to the immune defense system was studied by electron microscopy in the rat small intestine. The cells of the immune system (CIS) such as lymphocytes, eosinophils and macrophages penetrate the basal lamina into the epithelium and make close relationships with the absorptive cells. At the points of close apposition, the two cell membranes run parallel at a regular distance of about 20 nm. On the other hand, about 5% of the intestinal absorptive cells also penetrate the basal lamina into the lamina propria via their basal protrusions and show a similar close association with CIS. The basal protrusions contain many microfilaments; this indicates that they are structures with a definite function rather than a simple hernia. These findings are discussed with respect to the transport of antigenic molecules and of intercellular communication between CIS and the intestinal epithelium.

Animals↗

PubMed1988