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Biomedical subjects

K Takata

Publications and source records attributed to K Takata.

At least 235 records · Page 13Linked to original sources
PubMed1984

Whole-cell-mount cytochemistry by the colloidal gold labeling method. Combined transmission and scanning electron microscopic study of ConA binding sites in mouse macrophages.

Binding, redistribution, and endocytosis of colloidal gold (CG)-labeled concanavalin A (ConA) were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Mouse peritoneal macrophages were cultured on Formvar-coated platinum grids. Either fixed or unfixed cells were labeled by the indirect ConA-CG labeling method. Specimens were critical-point-dried and observed by TEM and SEM in the same region. Surface-bound ConA-CG was easily seen by SEM. Stereomicroscopic observation by TEM clearly showed the three-dimensional distribution of ConA on the cell surface as well as in the cytoplasmic vesicles and vacuoles. In the prefixed cells, CG was distributed randomly on the cell surface. When unfixed cells were labeled at 0 degree C, a similar binding pattern was observed, although the density of bound CG was decreased. When cells labeled with ConA-CG at 0 degree C were further incubated at 37 degrees C, redistribution and endocytosis of the label were seen. Endocytosed CG in the cytoplasmic vesicles and vacuoles was clearly seen by TEM. In addition, three-dimensional location and relationship with other organelles were easily observed. Combined TEM and SEM observation of CG-labeled whole-cell-mount specimens is a useful method to study the dynamics of cell-bound ligands.

Animals↗
PubMed1984

Use of colloidal gold and ruthenium red in stereo high-voltage electron microscopic study of Con A-binding sites in mouse macrophages.

Concanavalin A (Con A)-binding sites were labeled with colloidal gold (CG), stained with ruthenium red, and observed under a high-voltage electron microscope. Mouse peritoneal macrophages were labeled by the indirect Con A/CG labeling method at 0 degree C. After washing, some of the cells were incubated in phosphate-buffered saline (PBS) at 37 degrees C. The specimens were then stained with ruthenium red, to enhance the contrast of the cell surface, and embedded in Epon. Sections (0.3 approximately 3 micron thick) were cut and examined by high-voltage electron microscopy at accelerating voltages of 200 approximately 1,000 kV. Staining with ruthenium red provided a strong contrast of the cell surface and the invaginating tubules beneath it against the cytoplasm; in thick sections, both of them were clearly seen by stereomicroscopy. CG particles which represented Con A-binding sites were also sufficiently electron dense to be recognized by high-voltage electron microscopy of thick sections. The two- and three-dimensional distribution of CG particles on the ruthenium-red-positive cell surface was clearly visualized. At 0 degree C, Con A-binding sites were randomly distributed on the cell surface. The redistribution and endocytosis of Con A-binding sites were seen at 37 degrees C. The three-dimensional organization of membrane invagination, which represented the process of endocytosis, was clearly seen by stereomicroscopy. The combination of CG labeling and ruthenium red staining is a useful method for high-voltage electron microscopic analysis of the two- and three-dimensional distribution of CG-labeled ligands on the cell surface in thick sections.

Animals↗
PubMed1984

Glycoproteins responsive to the neural-inducing effect of concanavalin A in Cynops presumptive ectoderm.

To examine the possible occurrence of receptors in the ectodermal cell surface which apparently mediates the neural-inducing stimulus, a further experiment by using Con A was done in combination with the enzyme treatments. The presumptive ectoderm explants of Cynops gastrula were first treated with neuraminidase to remove sialic acid. Prior to the Con A treatment, the explants were treated with almond glycopeptidase, which cleaves the asparagine linkage between protein and oligosaccharide in glycoprotein and releases the oligosaccharide moiety intact containing mannose residue from the substrate. No neural induction occurred. When the explants were not treated with almond glycopeptidase, the neural induction frequency was found to be the same as that of the explants treated with only Con A. Biochemical analyses showed that when the fixed ectoderm explants were treated with almond glycopeptidase, several oligosaccharides were released and then fractionated by means of Bio-Gel P-4 filtration. Based on the strict specificity of almond glycopeptidase, these oligosaccharides are unmistakably asparagine-linked oligosaccharides with mannose residues. We discuss the hypothesis of involvement of glycoproteins in the first step of molecular events in the neural induction mechanism.

Amidohydrolases↗
PubMed1984

Glucocorticoid receptor in chick embryonic epidermis. Inhibition by progesterone of both the binding of glucocorticoid to the receptor and glucocorticoid-induced keratinization.

Our previous study showed that hydrocortisone (10(-8) M) induced epidermal alpha-type keratinization in 13-day-old chick embryonic tarsometatarsal skin cultured in a chemically defined medium. In this study, we show that typical glucocorticoid receptor is present in epidermal cells of chick embryonic cultured skin and that alpha-type keratinization of epidermal cells is completely prevented by the coexistence of a 100-fold excess concentration of progesterone with glucocorticoid. The physiologic importance of the receptor is suggested by some correlation between the ability of progesterone to block both the differentiation-induction and the binding of active glucocorticoid to the receptor.

Acyltransferases↗
PubMed1984

Purification and characterization of four proteases from a clinical isolate of Serratia marcescens kums 3958.

Four distinct proteases were purified to homogeneity from culture filtrates of Serratia marcescens kums 3958, a fresh isolate from a patient with a severe corneal ulcer. Purification was achieved by ammonium sulfate precipitation, DEAE-cellulose ion-exchange chromatography, and Sephadex gel filtration chromatography. The proteases were differentiated from each other by polyacrylamide gel electrophoresis with or without sodium dodecyl sulfate and by immunodiffusion in agarose gels. The molecular weights of these purified proteases were estimated to be 56 X 10(3), 60 X 10(3), and 73 X 10(3) (hereafter designated 56K, 60K, and 73K proteases, respectively). The 73K protease was separated into 73Ka and 73Kb upon isoelectricfocusing. The isoelectric points of the 56K (major) and 60K, 73Ka, and 73Kb proteases (minors) were approximately 5.3, 4.4, 5.8, and 7.3, respectively. Both 56K and 60K enzymes were completely inactivated by EDTA at pH 5.0 and were reactivated by zinc ion; thus, they are metalloenzymes, whereas 73K (73Ka and 73Kb) enzymes appear to be thiol proteases. Carbohydrate, cysteine, and cystine were not detected in the 56K and 60K proteases. Amino acid compositions, partial amino acid sequence, and enzymological and immunological properties revealed that these four enzymes are distinct from each other.

Chromatography, DEAE-Cellulose↗
PubMed1984

Changes in permeability of rabbit articular cartilage caused by joint contracture as revealed by the peroxidase method.

Changes in permeability of adult rabbit articular cartilage caused by joint contracture were studied by light and transmission electron microscopy, employing horseradish peroxidase (HRP) as an indicator. The knee joint was plaster-immobilized for 0, 2, 4, 6, or 8 weeks in the flexion position. One ml of 4% HRP was administered in the articular cavity of the knee joint and allowed to diffuse and permeate into the articular cartilage. Distribution of the permeated HRP was visualized in the cartilage taken from the lateral condyle of the femur, utilizing the DAB-H2O2 reaction. In the normal and the non-immobilized joints, the permeated HRP reached to the matrix and chondrocytes situated in the deep layer of the articular cartilage. HRP was heavily deposited in the intercellular matrices, particularly around the chondrocytes, and was actively endocytosed by these cells. In the plaster-immobilized joints, especially after 4 weeks or longer of immobilization, the administered HRP had not permeated well and was restricted to the surface (lamina splendens) and the superficial layer of the cartilage. These results show that administered HRP diffuses into the deep layer of the articular cartilage and is actively endocytosed by chondrocytes and that the permeability of articular cartilage is remarkably reduced by joint contracture.

Animals↗
PubMed1984

[A case of giant prostatic hypertrophy].

This report deals with a case of an 82-year-old male with a giant prostate that weighted 270 grams. Retropubic prostatectomy was performed successfully. The removed prostate adenoma consisted of adenomatous hyperplasia on pathology. Though the nomenclature of "giant prostatic hypertrophy" is not clear, we reviewed cases of over 200 grams of hypertrophy so far reported in Japan were as giant prostatic hypertrophy. Twenty two cases of giant prostatic hypertrophy have been reported in the Japanese literature to date and our case was the sixth heaviest ever reported in Japan.

Aged↗
PubMed1983

Distribution of glycoconjugates in normal human skin using biotinyl lectins and avidin-horseradish peroxidase.

Lectin binding patterns in normal human skin were studied using five different biotinyl lectins and avidin-horseradish peroxidase. The staining pattern was specific for each lectin. In the epidermis, peanut agglutinin (PNA) and soybean agglutinin (SBA) preferentially stained the cell membranes of keratinocytes in the spinous and granular cell layers, indicating changes in the saccharide residues during keratinocyte differentiation. In the secretory segment of an eccrine sweat gland, the superficial cells gave a strong granular staining with Ricinus communis agglutinin (RCA). Dolichos biflorus agglutinin (DBA) and SBA, on the other hand, strongly stained the basal cells. With these lectins, two types of cells in the secretory segment were clearly distinguished. These results show that (1) PNA and SBA binding sites increase during the course of keratinocyte differentiation, and (2) RCA, DBA, and SBA are good markers to distinguish two types of cells in the secretory segment of an eccrine sweat gland.

Avidin↗
PubMed1983

Changes in high density lipoproteins in patients with hepatobiliary diseases. Levels and lipid composition of HDL2 and HDL3 and LCAT reaction.

Lipids of HDL (high density lipoproteins) and their subfractions (HDL2 and HDL3), and LCAT activity (lecithin: cholesterol acyltransferase) were determined in hepatobiliary diseases without severe hyperbilirubinemia (less than 10 mg/dl). The decrease in major lipid constituents (cholesterol and phospholipids) of HDL was mainly attributable to the decrease in those of HDL3, except in some liver diseases of acute or severe stage (acute hepatitis in an acute stage and hepatoma) which were accompanied with a simultaneous moderate decrease in those of HDL2 and in fatty liver which showed a preferential decrease in those of HDL2. The LCAT activity also decreased in several diseases. Some of the hepatobiliary diseases, on the contrary, showed an increase in HDL-triglycerides (mostly in HDL3 and in some diseases also in HDL2) which might participate to some extent in secondary hyperlipidemia in the liver parenchymal diseases, although they were the minor lipid constituents of HDL. From results that HDL3- but not HDL2-cholesterol levels significantly correlated with serum total protein, albumin and choline esterase, it was suggested that the decrease in large constituents of HDL, particularly of HDL3, is caused by hepatocellular dysfunction which causes inhibition of protein and lipid syntheses in the liver in most of the hepatobiliary diseases except for fatty liver which has a preferential decrease in HDL2 lipids.

Adult↗
PubMed1982

Characterization and identification of the glucose transporter of human erythrocytes.

The glucose transporter was purified from human erythrocytes (Kasahara, M. and Hinkle, P.C. (1977) J. Biol. Chem. 252, 7384-7390). The following results support the conclusion that a major protein in the purified transporter fraction, zone 4.5 is the glucose transporter (or a part of the transporter) and is different from band 3: (1) peptide maps of zone 4.5 were similar throughout the broad band in sodium dodecyl sulfate-gel electrophoresis and were different from those of band 3, (2) specific binding of cytochalasin B was found to the transporter fraction, but not to a band 3 fraction, (3) the N-terminal amino acid analysis of the transporter fraction showed a single N-terminal of lysine, whereas the band 3 fraction showed no clear N-terminal, and (4) the rabbit antibody raised against the transporter fraction formed a precipitation line with the transporter fraction, but not with the band 3 fraction. A filtration apparatus was devised for quick and accurate measurement of cytochalasin B binding, with which results comparable to those from equilibrium dialysis were obtained.

Blood Glucose↗