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Biomedical subjects

S Irie

Publications and source records attributed to S Irie.

At least 127 records · Page 7Linked to original sources
PubMed1989

[Clinical and endocrinological studies of the luteinizing hormone-releasing hormone analogue therapy in prostatic cancer patients].

A luteinizing hormone-releasing hormone (LH-RH) analogue was administered for 3 to 32 months to 15 prostatic cancer patients in stage B-D (B:3, C:8, D:4). Intratesticular, intratubular and prostatic androgen levels were measured by radioimmunoassay before and after LH-RH analogue therapy. The measurement of serum prostatic acid phosphatase (PAP) and prostatic specific antigen (PA) levels was also conducted. Thereafter, we assessed the effect of the LH-RH analogue on androgen levels and the relation of prostatic tissue 5 alpha-dihydrotestosterone (DHT) level to the clinical response. The results were as follows: 1) Johnsen's mean germinal epithelium count was significantly decreased from 7.7 +/- 2.1 (mean +/- S.D.) to 4.3 +/- 2.3, and the wall thickness of seminiferous tubules was increased from 5.93 +/- 1.31 to 11.9 +/- 3.64 microns. 2) Plasma testosterone (T), intratesticular and intratubular androgen levels were significantly decreased (plasma T: from 4.40 +/- 1.84 to 0.61 +/- 0.32 ng/ml, intratesticular T: from 335.3 +/- 170.3 to 4.6 +/- 3.8 ng/g.t.w., DHT: from 25.3 +/- 11.7 to 3.7 +/- 2.7 ng/g.t.w., intratubular T: from 50.8 +/- 36.6 to 0.10 +/- 0.99 ng/g.t.w. and DHT: 7.54 +/- 3.20 to 0.63 +/- 0.90 ng/g.t.w.). 3) Crude nuclear DHT levels in prostatic tissue fell from 15.3 +/- 9.3 (N = 8) to 0.37 +/- 0.54 pg/mg protein (N = 3) and the level was non-detectable in 5 of 8 cases. 4) Complete remission was achieved in 1 patient, partial response in 5, objective stable in 8, and objective progression in 1 patient, according to Shimazaki's criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1989

Relationship of the glycan structure of glycoproteins to the desialylation process by rat liver endothelium.

To investigate the variations in desialylation of glycoproteins by liver endothelium, we compared endothelial desialylation for 3 glycoproteins, human ceruloplasmin, human and rat transferrin. Radiolabeled glycoproteins were chased through purified rat liver endothelium and then fractionated by lectin affinity chromatography. Endothelium processed glycoproteins were fractionated by RCA120 chromatography into sialylated and desialylated components. The latter was then studied by Con A chromatography. Desialylation occurred only when the molecule contained at least a single triantennary chain of glycan. Desialylation was minimal in the case of human transferrin which contains mostly biantennary branching pattern. Thus, it appears that a single triantennary glycan chain is necessary and sufficient to trigger desialylation of glycoproteins by liver endothelium and this process is an all-or-none phenomenon.

Animals↗
PubMed1988

Desialation of transferrin by rat liver endothelium.

To examine the role of liver endothelium in desialation of transferrin (TF), pulse-chase studies were done by incubation of either 3H (sialic acid labeled)-, or 125I, or 59Fe (protein core labeled)-TF with fractionated liver endothelium. While 125I or 59Fe labels were externalized after initial binding and internalization, a large proportion of 3H label was internalized and remained within the cell. When the supernatant of these experiments was studied by isoelectricfocusing and Ricinus communis agglutinin (RCA120) affinity chromatography, generation of asialotransferrin was noted by both techniques. Incubation of liver endothelium with double-labeled TF (sialic acids with 3H and protein core with 125I or 59Fe) led initially to a concordant uptake of the two labels, which were then dissociated and 3H was retained by the cell. These findings indicate desialation of TF by liver endothelium. The significance of these findings in the pathogenesis of hepatic siderosis is discussed.

Animals↗
PubMed1988

Analysis of the microheterogeneity of the glycan chain of rat transferrin.

To investigate the microheterogeneity of the glycan chain of rat transferrin, either the protein moiety was labeled with 125I or the sialyl residues with 3H. The molecule was then subjected to Con A chromatography. Three components were obtained. Each was enzymatically desialylated and sialyl/protein molar ratios were calculated. The native protein as well as the 3 components were also subjected to isoelectric focusing. The results indicated that rat transferrin may have 3 types of glycan chain: The major type (60%) corresponds to a molecular species with triantennary branching, while 30% consists of molecules with biantennary and 10% with tetraantennary branching. The last species has not been previously described.

Animals↗
PubMed1987

Longitudinal differentiation of metaphase chromosomes of Indian muntjac as studied by restriction enzyme digestion, in situ hybridization with cloned DNA probes and distamycin A plus DAPI fluorescence staining.

The longitudinal differentiation of metaphase chromosomes of the Indian muntjac was studied by digestion with restriction enzymes, in situ hybridization with cloned DNA probes and distamycin A plus DAPI (4'-6-diamidino-2-phenylindole) fluorescence staining. The centromeric regions of chromosomes 3 and 3 + X of a male Indian muntjac cell line were distinct from each other and different from those of other chromosomes. Digestion with a combination of EcoRI and Sau3A revealed a pattern corresponding to that of C-banding. Digestion with AluI, EcoRII or RsaI yielded a band specific to the centromeric region only in chromosomes 3 and 3 + X. Furthermore, HinfI digestion yielded only a band at the centromeric region of chromosome 3, whereas DA-DAPI staining revealed a single band limited to the extreme end of the C-band heterochromatin of the short arm of 3 + X. These results suggest that centromeres of Indian muntjac chromosomes contain at least four different types of repetitive DNA. Such diversity in heterochromatin was also confirmed by in situ hybridization using specific DNA probes isolated and cloned from highly repetitive DNA families. Heterozygosity between chromosome homologs was revealed by restriction enzyme banding. Evidence is presented for the presence of nucleolus organizer regions (NORs) on the long arm of chromosome 1 as well as on the secondary constrictions of 3 and 3 + X.

Animals↗
PubMed1987

Structure of the yeast HIS5 gene responsive to general control of amino acid biosynthesis.

The nucleotide sequence of a 2.1 kb DNA fragment bearing the HIS5 gene of Saccharomyces cerevisiae, which encodes histidinol-phosphate aminotransferase (EC 2.6.1.9), has been determined. An open reading frame of 1,152 bp was found. S1 nuclease mapping indicated that the major transcription starts at position -37 from the ATG codon and the minor (approximately 20%) at -34 in both repressive and derepressive conditions. Northern analysis indicated that transcription of the HIS5 gene is under the general control of amino acid biosynthesis. The 5' noncoding region of the gene, thus far examined up to position -616, contains three copies of sequences homologous to the short repeats of the consensus sequence, 5'-AATGTGACTC-3', suggested for general amino acid control in the HIS1, HIS3, HIS4, and TRP5 at positions -336, -275 and -205. The consensus sequence closest to the open reading frame was shown to be necessary but not sufficient for general amino acid control, by examination of beta-galactosidase appearance in S. cerevisiae cells carrying various mutant HIS5 promoter regions fused to the lac'Z gene and inserted at the leu2 locus of chromosome III.

Amino Acid Sequence↗
PubMed1987

Transferrin-mediated cellular iron uptake.

The basic model for cellular uptake of iron relies on the iron-chelating protein transferrin (Tf), which is capable of binding iron under one set of conditions and releasing it under another set of conditions. Tf has specific membrane receptors on the surface of the cells that require iron. Tf-receptor binding is followed by internalization through a system of coated pits and vesicles. The rapid decline of pH of these vesicles leads to release and sequestration of iron by the cell. Apotransferrin-receptor complex returns to the cell surface, where, under neutral pH conditions, apotransferrin is dissociated. Other models for cellular uptake of iron include extraction of iron from Tf on the cell surface without internalization, uptake by adsorptive mechanism, and fluid-phase endocytosis. Recent advances in cellular and molecular biology, gene cloning, and monoclonal antibody technique have elucidated many features of these processes at a molecular level. These advances are reviewed and prospects for future work discussed.

Animals↗
PubMed1987

Nucleotide sequencing and characterization of the genes encoding benzene oxidation enzymes of Pseudomonas putida.

The nucleotide sequence of the genes from Pseudomonas putida encoding oxidation of benzene to catechol was determined. Five open reading frames were found in the sequence. Four corresponding protein molecules were detected by a DNA-directed in vitro translation system. Escherichia coli cells containing the fragment with the four open reading frames transformed benzene to cis-benzene glycol, which is an intermediate of the oxidation of benzene to catechol. The relation between the product of each cistron and the components of the benzene oxidation enzyme system is discussed.

Amino Acid Sequence↗
PubMed1986

Liver endothelium desialates ceruloplasmin.

Our previous work indicated that ceruloplasmin (CP) is transported through liver endothelium via a receptor-mediated mechanism and is subsequently externalized on the abluminal side. In the present work 125I or 3H-labeled ceruloplasmin was chased through the endothelium and the supernate was subjected to affinity chromatography using RCA120 column. Evidence was obtained that liver endothelium completely desialates CP in the course of its transport. The results substantiated the view that desialated CP is subsequently removed by hepatocytes through asialoglycoprotein receptors.

Animals↗
PubMed1986

Mapping of the rat liver endothelial membrane with lectins and glycosylated ferritins.

We explored the luminal surface of liver sinus endothelium for the presence of lectin receptors and lectinlike substances capable of interacting with specific sugars. We used ferritin-conjugated lectins and glycosylated ferritins as probes. Incubation of small blocks of rat liver with these probes led to the binding of concanavalin A (on A), Ricinus communis (RCA), wheat germ agglutinin (WGA), phytohemagglutinin (PHA) and mannosyl ferritins to the luminal surface of endothelium. Ulex europaeus agglutinin I (UEA), fucosyl, galactosyl, and chitobiosyl-ferritins did not bind. The binding was patchy and sparse in the case of Con A and mannosyl-ferritins but uniform for others. Binding density did not correlate with hemagglutinability of lectins, suggesting that the difference in the hemagglutinability of these lectins did not account for the difference in their binding densities. Bindings were all completely inhibited in the presence of excess specific sugar inhibitors, indicating the specificity of binding. The distribution of binding was segregated on the endothelial membrane, being heaviest on luminal pits. To define the functional significance of this segregated distribution, sinus endothelium was compared to portal-vein endothelium in which endothelial fenestrations are also seen; and these fenestrations as well as pits may be covered by a thin diaphragm. Of interest was the total absence of binding to the diaphragm. The significance of these findings is discussed.

Animals↗
PubMed1986

Expression of biologically active human interleukin 1 subpeptides by transfected simian COS cells.

"Interleukin 1" (IL-1) is a term used to describe the family of macrophage-derived proteins that mediate many immune and inflammatory reactions. We have previously described the molecular cloning and sequencing of the cDNA encoding the predominant (neutral) form of human IL-1, which has been designated IL-1 beta. We report here that transfection of simian COS cells with this cDNA clone results in the transcription of IL-1 mRNA and the synthesis of antibody-neutralizable intracellular IL-1 biological activity. In addition, selective deletion of regions of the IL-1 cDNA judged not to be essential for function, on the basis of conserved sequence homology, resulted in localization of a "core" region responsible for a majority of the biological activity. These results permit mapping the active site of IL-1 to a peptide of 6970 molecular weight located within the carboxyl third (between Met-136 and Gln-197) of the IL-1 precursor.

Animals↗
PubMed1986

Purification and characterization of rat bone marrow endothelial cells.

A method is described to obtain endothelial cells from rat bone marrow with high purity and viability. Marrow cell suspensions were prepared by collagenase and subjected to discontinuous gradient centrifugation on Percoll (densities 1.04 and 1.06). Endothelial cells were concentrated in the middle layer as demonstrated by electron microscopy and flow cytometry as well as fluorescent microscopy after staining for factor VIII antigen. Cells of this layer were then subjected to centrifugal elutriation and highly purified endothelial cell preparations were obtained with flow rates of 15-20 ml/min. By fluorescent microscopy, 49%-51% of these cells were factor VIII positive. Identification by means of electron microscopy indicated a much higher purity of endothelium ranging from 63% to 90% with a yield in the range of 10(6) cells and a viability exceeding 90%. Some technical considerations in the development of this method are discussed. This method permits in vitro experiments on relatively high purity, high viability preparations of marrow endothelium.

Animals↗
PubMed1986

Structural features of isolated, fractionated bone marrow endothelium compared to sinus endothelium in situ.

Structural features of isolated, fractionated rat bone marrow endothelium were compared to those of marrow sinus endothelium in situ. Marrow endothelium was purified, first by density gradient sedimentation on Percoll and then subjected to centrifugal elutriation. Using antifactor VIII antibody staining (indirect immunofluorescent method), preparations of greater than 50% purified endothelium were obtained. By SEM, these cells were about 10 microns in size and showed smooth surface and numerous invaginations. These features were also observed in the in situ endothelium obtained by perfusion-fixation and freeze-cracking. In addition, in situ endothelium displayed numerous hemopoietic cells in migration through the endothelium. By TEM, isolated endothelium showed numerous vesiculations, giving the cell sponge-like appearance. This corresponded to numerous intracellular vesicles in sinus endothelium in situ, reflecting high magnitude of fluid and molecular transport across the endothelium. Weibel-Palade bodies were not seen in either form of the endothelium, despite the positive reaction for factor VIII-related antigen. This finding suggested that the cell, while possessing factor VIII-related antigen, does not store this protein.

Animals↗
PubMed1984

Subunit constitution of electrophoretically purified xanthine dehydrogenase of avian liver.

Chick liver xanthine dehydrogenase was highly purified by preparative polyacrylamide gel electrophoresis at the final step of purification, which allowed removal of another contaminating, xanthine-oxidizing enzyme showing a molecular mass of about 380K daltons. Purified XDH showed a specific activity higher than 2,500 units per mg of protein. On treatment with sodium dodecyl sulfate and 2-mercapto-ethanol, XDH was split into two subunits (named as alpha and beta) of different size in an equimolar ratio. The molecular weights of these subunits were estimated as 155K for alpha and 135K for beta. In the form of sodium dodecyl sulfate-complex, subunit alpha tended to degrade into smaller peptides, whereas subunit beta was relatively stable.

Aging↗