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Biomedical subjects

E Nagao

Publications and source records attributed to E Nagao.

27 records · Page 2Linked to original sources
PubMed1994

Structural and functional studies on biliverdin-associated cyanoprotein from the bean bug, Riptortus clavatus.

Structural and functional analysis were performed on biliverdin-associated cyanoprotein (CP) from the hemolymph (CP-1 to CP-4) and eggs (CPegg, identical to CP-1) of the bean bug, Riptortus clavatus. Isoelectric focusing analysis of purified CPegg and CP-4 revealed that they are composed of a single alpha subunit and a more acidic beta subunit respectively. N-terminal amino acid sequencing revealed that there are six different amino acid residues between the two subunits up to the 29 cycles determined, indicating that they are encoded by different genes. Appreciable sequence similarities in N-terminal region are found between the CP subunits and several insect hexamers. By chemical cross-linking analysis these CPs were demonstrated to have hexameric structures. Two dimensional peptide mapping revealed that alpha and beta subunits share common structures in part and that CP-2 and CP-3 are hybrid molecules bearing both alpha and beta subunits. From these results the molecular structure of CPs was established as follows: CP-1 (CPegg) = alpha 6; CP-2 = alpha 4 beta 2; CP-3 = alpha 2 beta 4; CP-4 = beta 6. In addition, using 125I-labeled CPegg and CP-4, in vivo incorporation into several tissues was examined during the nymphal-adult development. During the late phase of the 5th instar, CP-4 was sequestered preferentially over CPegg by the fat body, while after emergence both proteins were suggested to be incorporated into the newly-formed cuticle. CPegg was sequestered massively by the developing ovaries whereas no appreciable incorporation of CP-4 was observed.

Amino Acid Sequence↗
PubMed1991

Formation of hair follicles from a single-cell suspension of embryonic rat skin by a two-step procedure in vitro.

A technique for culturing skin was devised whereby hair follicles in a normal state were generated from a single-cell suspension of embryonic rat skin. Dissociated cells obtained by trypsinization of the day-15 embryonic lip were cultured by a two-step procedure in vitro. Reorganization of hair-follicle rudiments was accompanied by reaggregation of the cells during a 24-hour initial culture with rotation, and the rudiments differentiated into hair follicles within a week during subsequent subculture of the cell aggregates by floatation. The light-microscopic features and the size of the follicles were similar to those of day-18 vibrissa follicles during normal development in vivo. Furthermore, the stratification of cells, including subcellular differentiation, and the ultrastructure of the hair follicles generated in vitro were similar to those of normal hair follicles with well-keratinized hair shafts. The present system appears to be a useful model for analytical studies in vitro on the formation of hair follicles and for studies designed to facilitate the transplantation of human hair.

Animals↗
PubMed1991

Further characterization of locust low density lipophorin induced by adipokinetic hormone.

This study was designed to resolve basic questions concerning the nature of low density lipophorin (LDLp) which is induced by adipokinetic hormone (AKH). For this purpose, lipophorin was fractionated by density gradient ultracentrifugation and each fraction containing lipophorin was analyzed for diacylglycerol and associated apolipophorin-III (apoLp-III). The diacylglycerol content of LDLp fractions increased significantly as the density of the fraction decreased (116 micrograms/100 micrograms protein at a high density to 209 micrograms/100 micrograms protein at a lower density). On the other hand, the content of diacylglycerol in each fraction of HDLp remained almost constant (33 micrograms/100 micrograms protein). It was also found that the number of apoLp-III molecules associated with LDLp increased as the density decreased (from 6.9 mol/mol LDLp to 13.2 mol/mol LDLp). However, electron microscopic observation showed that LDLp particles in each of the fractions were extremely heterogeneous in size with diameters of 29.4 +/- 6.8 nm, 27.1 +/- 5.5 nm, and 26.3 +/- 5.7 nm for low, medium, and high density fraction, respectively. HDLp particles were very homogeneous in size irrespective of the fraction (15.9 +/- 1.5 nm, 15.6 +/- 1.5 nm, and 15.6 +/- 1.3 nm for the respective fractions). A theoretical analysis based on all the experimental data strongly supports the hypothesis that the heterogeneity in the size of LDLp particles does not reflect different densities, but rather, heterogeneity is the result of intermolecular fusion between LDLp particles of the same density.

Animals↗
PubMed1990

Ontogenetic transition of wound healing pattern in rat skin occurring at the fetal stage.

Full-thickness excisional wounds were made in the dorsal skin of rat fetuses at day 16 and day 18 of gestation. A small patch of skin surrounding the open wound was cut out, mounted on a plastic ring and incubated in an organ culture system. In the presence of serum, the open wound in the day-16 fetal skin closed within three days of culture. During the wound-closure process, no new structures were formed in the wound space, and no conspicuous changes were noted in the histological architecture of the surrounding skin during culture, indicating that the wound closure may result from a centripetal movement of the surrounding skin only. In contrast, the size of the open wound in the day-18 fetal skin remained almost unchanged for one week, but a thin acellular network spread over the wound space within one day of culture. The predominant component of the network was cross-linked fibrin, as disclosed by scanning electron microscopy and sodium dodecylsulfate-polyacrylamide gel electrophoresis followed by immunoblotting. The network served as a scaffold for the ingrowth of fibroblast-like cells. These stage-dependent differences in fetal wound healing were consistent with an in vivo study showing that the day-16 wound was covered with the surrounding skin itself, whereas the day-18 wound was covered with newly formed epidermis and invaded by inflammatory cells. The present investigation strongly indicates the prenatal occurrence of a fetal-to-adult transition in the wound-healing pattern of rat skin.

Animals↗
PubMed1987

Structural study of the asparagine-linked oligosaccharides of lipophorin in locusts.

The complete structure of oligosaccharides from locust lipophorin was studied. The asparagine-linked oligosaccharides were first liberated from the protein moiety of lipophorin by digestion with almond glycopeptidase (N-oligosaccharide glycopeptidase, EC 3.5.1.52). Two major oligosaccharides (E and F), separated by subsequent thin-layer chromatography, were analyzed by methylation analysis and 1H-NMR. Based on the experimental data, the whole structure of oligosaccharide E was identified as Man alpha 1----2Man alpha 1----6(Man alpha 1----2Man alpha 1----3) Man alpha 1----6(Man alpha 1----2Man alpha 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAc. The data also revealed that oligosaccharide F is identical with oligosaccharide E in the structure, except for one glucose residue that is linked to the nonreducing terminal Man alpha 1----2 residue.

Animals↗