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Biomedical subjects

T Tezuka

Publications and source records attributed to T Tezuka.

At least 199 records · Page 11Linked to original sources
PubMed1980

Thrombin inhibitors. 3. Carboxyl-containing amide derivatives of N alpha-substituted L-arginine.

A series of N alpha-(arylsulfonyl)-L-arginine amide derivatives having carboxamide N-substituents with a carboxyl group was prepared and tested as inhibitors of the clotting activity of thrombin. The most inhibitory compounds were obtained when a carboxyl group was introduced into the carbon next to the amide nitrogen of N alpha-(arylsulfonyl)-L-arginine amide derivatives, e.g., N alpha-(arylsulfonyl)-L-arginyl-N-butyl-, N-(methoxyethyl)- or N-(tetrahydrofurfuryl)glycine and 4-alkyl-1-[N alpha-(arylsulfonyl)-L-arginyl]-2-piperidinecarboxylic acid, with an I50 of 1-3 X 10(-7) M.

Animals↗
PubMed1980

Cutaneous calculus - its pathogenesis.

The cutaneous calculus of 11 patients were examined. Histologically they were classified into three types: the first type, seen in an early lesion, consisted of a basophilic mass; the second type consisted of a mass and various-sized granules; and the third type consisted entirely of granules. Histochemically, the mass contained acid mucopolysaccharides. In the granules neutral mucopolysaccharides were found. There were numerous, vacuolated mast cells and various-sized, calcified amorphous areas evident with electron microscopic examination of an early lesion.

Calculi↗
PubMed1980

The synthesis of the cystine-rich proteins in rat epidermis: I. Analysis by [35S]cystine incorporation.

Three-day-old Sprague-Dawley rats were injected intraperitoneally with 100 muCi of [35S]cystine. They were then sacrificed at 30 minutes, 2, 4, and 10 hours. The skins were epilated by the beeswax-resin procedure and the epidermis was separated by soaking in NH4Cl solution. Neither hair with hair follicles nor hair sheath was attached to the epidermal sheets after the epilation. Keratohyalin granules were solubilized after the freezing and thawing procedure. Living cell layers were separated from stratum corneum following further incubation in NH4Cl solution. Both the living cell layers and the stratum corneum were extracted with 8 M alkaline urea. Seventy-two to 92% of the total radioactivity incorporated into epidermal proteins was found in the urea-insoluble fraction of the stratum corneum. Only 2.4 to 6.4% of the total radioactivity was incorporated into the keratohyalin granular fraction. The specific radioactivity which was incorporated into the urea-insoluble fraction of the stratum corneum was still increasing 10 hours after injection, though the radioactivity in other fractions was decreasing at 10 hours following injection. The highest specific radioactivity of [35S]cystine was found in the urea-soluble fraction of the living cell layers, and was being rapidly turned over.

Animals↗
PubMed1978

Purification and properties of a second enzyme catalyzing the splitting of carbon-mercury linkages from mercury-resistant Pseudomonas K-62.

An enzyme (splitting enzyme 2) which catalyzes the splitting of carbon-mercury linkage of arylmercury compounds was found in extracts of mercury-resistant Pseudomonas K-62. This enzyme was purified about 725-fold by treatment with streptomycin, precipitation with ammonium sulfate, and successive chromatography on Sephadex G-75 and diethylaminoethyl-cellulose. A purified preparation of the enzyme showed a single band in electrophoresis either on polyacrylamide or sodium dodecyl sulfate-containing polyacrylamide gels. The molecular weight of the enzyme was estimated to be 20,000 (determined by Sephadex G-75 gel filtration) 17,000 (determined by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis). The enzyme showed a Km of 180 micron and a Vmax of 3.1 mumol/min per mg for p-chloromercuribenzoic acid and a Km of 250 micron and a Vmax of 20 mumol/min per mg for phenylmercuric acetate. The optimum temperature and pH for the reaction were 40 degrees C and 5.0, respectively.

Chloromercuribenzoates↗
PubMed1978

Electron microscopic changes of keratohyalin granules during the freezing and thawing procedure.

After 3-day-old rat skins were treated by freezing and thawing procedures, small empty spaces were formed both in keratohyalin granules and in the cytoplasm of the granular cells. When the skin specimens thus treated were further incubated in 50 mM Tris-HCl buffer, pH 8.6, for 15 min, keratohyalin granules were solubilized, leaving electron dense rims. Small electron dense or less dense particles were detaching from these rims. Cell membranes were also disrupted at various regions. Desmosomal structures in the stratum granulosum cells were all preserved.

Animals↗
PubMed1978

The constituents of keratohyalin granules of newborn rat epidermis under an electron microscopy.

Three-day-old rat skins were treated either by the freezing--thawing method or by the tetraphenylboron technique. After the former procedure, keratohyalin granules were solubilized, leaving empty spaces with an electron-dense or less dense rim. Particles roughly 200 A in diameter, which were either electron-dense or less dense, were observed in the empty spaces and also seen detaching from the rim. After the freeze--thaw procedure, two types of keratohyalin granule were observed. The one is the same electron-dense granule as keratohyalin granules in vivo and the other is the granule, the electron density of which was identical with tonofilaments. Both granules were granular rather than fibrous in structure.

Animals↗
PubMed1978

The fluroescent profiles of keratohyalin granules of newborn rat epidermis with a new fluorescent thiol reagent (DACM).

A highly specific fluorescent thiol reagent, N-(7-Dimethylamino-4-methyl-coumarinyl)maleimide (DACM) has been used to examine the newborn rat skin in order to elucidate the cystine-rich keratohyalin granules or dense homogeneous deposits. After reduction of the disulphide bond with 2-mercaptoethanol, the periphery of the stratum corneum cells showed a very distinct fluorescence and the cytoplasm of the stratum corneum, granulosum and spinulosum showed moderate fluorescence. No fluorescence was observed, however, over the keratohyalin granules themselves. Intense, spotty fluorescence was observed from the remnants of nuclei and at the periphery of large keratohyalin granules of the stratum granulosum cells, which were assumed to be dense homogeneous deposts according to their distribution pattern. As the intense fluorescence elicited with DACM determines the abundance of cystine content in the material, cystine was found to be very scarce in keratohyalin granules, but abundant in dense homogeneous deposits and at the periphery of the stratum corneum cells.

Animals↗
PubMed1977

Melanosomes of pigmented basal cell epithelioma.

Electron microscopic examination of a pigmented basal cell epithelioma of scrotal skin revealed many tumor cells and melanocytes which were laden with large packages of melanosomes. In tumor cells these packages were delimited by either single- or double-limiting membranes or were not membrane bound. The matrix of these large complexes was less electron dense and homogeneous than normal, containing electrontranslucent droplets besides melanosomes. No remnants of intracellular organelles such as nucleus, mitochondria or ribosomes could be found. The basal cell epithelioma cells in this case appear to have differentiated toward fetal basal cells and have developed the ability to phagocytize large packages of melanosomes.

Basal Cell Carcinoma↗
PubMed1976

Purification and properties of an enzyme catalyzing the splitting of carbon-mercury linkages from mercury-resistant Pseudomonas K-62 strain. I. Splitting enzyme 1.

An enzyme (S-1) which catalyzes the splitting of carbon-mercury linkages of organomercury compounds was purified about 24-fold from the cell-free extract of mercury-resistant Pseudomonas K-62 strain by treatment with streptomycin, precipitation with ammonium sulfate, and successive chromatography on Sephadex G-150, DEAE-Sephadex, and DEAE-cellulose. A purified preparation of the enzyme showed a single band on polyacrylamide gel electrophoresis, and was colorless. The molecular weight of the enzyme was estimated to be 19,000, and Km was 5.3 X 10(-5) M for p-chloromercuribenzoic acid (PCMB). The temperature and pH optimum for the reaction were 50degrees and 7.0, respectively. The enzyme was capable of catalyzing the decomposition of methylmercuric chloride (MMC), ethylmercuric chloride (EMC), phenylmercuric acetate (PMA), and PCMB in the presence of a sulfhydryl compound to form a mercuric ion plus methane, ethane, benzene, or benzoic acid, respectively. The mercuric ion thus formed was reduced to metallic mercury by metallic mercury-releasing enzyme (MMR-enzyme).

Chloromercuribenzoates↗
PubMed1976

Electron microscopic, histochemical and disc gel electrophoretic studies on the deoxycholate soluble proteins from human plantar horny layers.

The matrix proteins of human plantar horny layers were extracted with deoxycholate, purified and examined with the light and electron microscopes, and their histochemical characteristics were investigated. About 44.3% of the total proteins was released into the 270,000 X g supernatant fraction, following incubation with deoxycholate, and the precipitate obtained by dialysing this supernatant fraction consisted of fine granular materials which were found to be electron dense, round material under the electronmicroscopy. Small electron dense dots were seen on the surface of this material. This pellet was positive with Pauly's reagent, toluidine blue and Harris hematoxylin-eosin. However, the material further purified by the molecular sieve chromatography was negative with Pauly's reagent. And it had been proved to be of keratohyalin granules origin by the indirect immunofluorescent study. Another protein fraction which was obtained by the molecular sieve chromatography was positive with diazotized sulfanilic acid and showed tinctorial properties as keratohyalin granules show in vivo.

Deoxycholic Acid↗
PubMed1976

Keratosis punctata palmaris et plantaris. A morphological study on the relation to the epidermal sweat duct unit.

The palmar and plantar pits of keratosis punctata palmaris et plantaris were examined histologically in both vertical and horizontal sections. Pits were located in the crista superficialis epidermis, especially in the orifice of the sweat duct, but no iodine-starch reaction was detected in pits by perspiration testing. In the center of a pit was a parakeratotic wedge, deflecting the squamous cell layers downwards. The sweat duct was found in this parakeratotic wedge, and was occasionally obstructed.

Aged↗
PubMed1975

Hybridization of polymers of antibiotic C-nucleoside phosphates, poly(formycin phosphate) and poly(laurusin phosphate)

The ability of complex formation of poly-(formycin phosphate), poly(F), and poly(laurusin phosphate), poly(L), with the polymers of natural polynucleotides was examined mainly by mixing experiments in 0.1 M NaCl-0.05 M sodium cascodylate buffer (pH 7.0) at 2 degrees. Poly(F) formed complexes with poly(U) and poly(I) in the ratio of 1:1 and 1:2, respectively. Poly(L) formed complexes with poly(A) in 2:1 ration and poly(C) in 1:2 and 2:1 ratios in addition to a self-complex. Poly(F) and poly(L) also formed a 1:2 complex between them. Some of these complexes were assumed to contain novel types of base pairings using the 7-NH group. Thus it was concluded that poly(L) could form complexes with both, the oligomer of cycloadenylic acid (øcn-120 degrees) and polymers of natural nucleotides (øcn0degrees), showing flexibility of the torsion angle of the laurusin residue.

Adenosine Monophosphate↗
PubMed1975

Polynucleotides. XXXII. Further studies on the synthesis of oligonucleotides containing 8,2'-S-cycloadenosine.

A dinucleoside monophosphate, 8,2'-anhydro-8-mercapto-9-beta-D-arabinofuranosyladenine phosphoryl-(3'-5')-inosine (AspI) was synthesized by the condensation of protected 8-mercapto-adenosine 2',3'-cyclic phosphate and 2',3'-isopropylideneinosine with diphenylphosphorochloridate. 8-Mercaptoadenosine 2',3'-cyclic phosphate was polymerized by using tetraphenyl pyrophosphate as the condensing reagent. As oligonucleotides, thus obtained, contained some uncyclized 8-mercaptoadenosine residues and were cleaved at these sites with 0.3N KOH. As 5'-phosphate was synthesized and polymerized with DCC to give oligonucleotides with chain lengths 2 to 9.

Adenosine↗
PubMed1975

Photoactivation of NAD Kinase through Phytochrome: Phosphate Donors and Cofactors.

The specificities of phosphate donors and the effects of metal chelating agents and divalent metal ions on NAD kinase activation by phytochrome-far red-absorbing form (Pfr) were examined. ATP was the most efficient phosphorylating agent. Uridine 5'-triphosphate, cytidine 5'-triphosphate (CTP), inosine 5'-triphosphate, and guanosine 5'-triphosphate in this order caused significant phosphorylation in the dark. Under red light, striking photoactivation of NAD kinase was obtained with ATP and subsequently CTP.In the presence of exogenous Mg(2+), which is required for NAD kinase activity, alpha-nitroso-beta-naphthol, cyanide, and dimethylglyoxime, strongly inhibited the activation by red light without affecting the level of NAD kinase in the dark.Of the divalent cations tested with the KCN-treated phytochrome preparation, only Co(2+) was effective for photoactivation of NAD kinase. Even when Mg(2+), an essential component of NAD kinase, was added to the assay system, the further addition of Co(2+) was required for the activation of NAD kinase by Pfr.

Journal Article↗
PubMed1975

Thickened cellular envelope of the horny cells in cow snout epidermis.

The cow snout epidermis consists of two different parts. The one has the granular cell layers, and the other not. Electron-microscopically, the generation of the lamellated granules and the thickened cellular envelope of a horny cell were noted in both regions. In the horny cell layer the remnant of the lamellated granules were observed locating in the intercellular space, that is, outside of the thickened cellular envelope. The thickened cellular envelope was generated by the precipitation of electron dense material along the inner leaflet of the plasma membrane, but neither by the attachment of small keratohyalin granules to the plasma membrane nor by the coating of the plasma membrane with the content of lamellated granules.

Animals↗
PubMed1975

Products of epidermal protein synthesis.

The products of epidermal protein synthesis in tissue slice and cell-free systems have been characterized by chromatographic, electrophoretic, and immunologic methods. Radiolabeled proteins of heterogeneous size are found in the supernatant and particulate fractions from both systems. The major labeled proteins in the supernatant fraction have molecular weights of approximately 43 000 and 65 000. The natively-insoluble proteins of the particulate fraction were solubilized either with desoxycholate or alkaline urea. Subsequent analysis of theses fractions yielded a labeled, high molecular weight, urea-soluble protein whose electrophoretic mobility was slower than that of the heavy chain of myosin. The immunologic reaction between the radiolabeled fraction and antibody raised against filamentous protein suggests that synthesis of proteins identical to epidermal filamentous protein occurs in the in vitro systems.

Animals↗