Search PubMed⌕ Search

Biomedical subjects

K Fukuyama

Publications and source records attributed to K Fukuyama.

At least 181 records · Page 10Linked to original sources
PubMed1982

Differences in the behavior of SH-protease inhibitor of rat epidermis on cathepsins B and H.

1. SH-protease inhibitor was purified from newborn rat epidermis and its activity against cathepsins B and H compared using alpha-N-benzoyl-DL-arginine-2-napthylamide as a substrate. 2. Preincubation of the inhibitor with the enzymes at 37 degrees C resulted in increased inhibitor activity for cathepsin B but not for cathepsin H: pH 7.0 was more effective than the lower pH for the increase. 3. The inhibition was noncompetitive regardless of the preincubation conditions and the inhibition was greater for cathepsin H than cathepsin B. 4. These findings suggest that there is an SH-protease inhibitor of newborn rat epidermis which has different biological behavior against cathepsins B and H.

Animals↗
PubMed1982

Autotransplantation of hepatic granulomas into the skin of mice with Schistosoma mansoni infection.

Hepatic egg granulomas of mice infected with Schistosoma mansoni were transplanted into the skin of the same animal and changes occurring to macrophages, eosinophils, and mast cells over time were studied by light and electron microscopy and by autoradiographic techniques. Disappearance of cellular components about the egg granulomas occurred within 1 week; the entire implant became encapsulated by inflammatory cells and stroma. By 3 weeks mononuclear cells and macrophages reorganized the granulomas around the eggs and neutrophils disappeared. Activated macrophages contained both secretory rough endoplasmic reticulum and lysosomal-dense bodies. Granuloma size increased up to 5 weeks after implantation and mast cells and eosinophils tended to migrate into the granulomas. The mast cell index always remained lower than in the original hepatic granulomas, while eosinophils were seen in large numbers. During 3 to 8 weeks after implantation mononuclear cells undergoing DNA synthesis in the granulomas ranged from 2.9-4.8%. Some 3-week-old autotransplants were injected with 3H-thymidine and biopsied from 1 to 21 days later. Labeled mononuclear cells peaked in the granulomas by 10 days (24%) and the numbers fell off sharply after that. These findings indicate that autologously implanted schistosome egg granulomas can be maintained successfully in the skin for prolonged periods with marked ingress of macrophages and eosinophils. The autoradiographic data suggest the lesions are high turnover granulomas.

Animals↗
PubMed1982

Biochemical properties of thiol proteinase inhibitor purified from psoriatic scales.

Epidermal thiol proteinase inhibitor (EPI) was extracted from normal and psoriatic cornified cells with 10 mM Tris-HCl, pH 8.0, and purified by papain-Sepharose affinity chromatography and gel filtration. Both EPIs showed a single band and the same mobility in gel electrophoresis with and without sodium dodecyl sulfate. Their immunological identity also was seen by agar diffusion. The inhibitor activity of EPIs to papain and rat liver lysosomal enzymes which caused a local inflammatory reaction after intradermal injection was determined on alpha-N-benzoyl-DL-arginine-2-naphthylamide and azocasein. Their activities to papain were the same at pH 8.0, but EPI of psoriasis showed only 50% of the activity of normal cells at pH 5.0 and 6.0. EPI of normal cells was heat stable, while that of psoriasis was reduced in activity after heating at 90 degrees C. Inhibitor activity of EPI from psoriatic cells toward the lysosomal enzymes, cathepsin B and/or cathepsin H and cathepsin L, was also inferior to EPI from normal cells at all pHs studied. We suggest the possibility that the inflammatory response associated with psoriasis seems in part to result from epidermal cells producing a less effective EPI, which may be a natural anti-inflammatory substance.

Animals↗
PubMed1982

Partial purification and characterization of angiotensin-converting enzyme in mouse and human skin.

The chemical properties of skin angiotensin-converting enzyme were characterized in mouse and human. In newborn mice, dermis contained almost all activity (1.3 mU/mg), of which 30% was in the 22,000 kappa g supernatant and 70% in the pellet which could be solubilized by Triton X-100. The activity increased sharply during the first 6 weeks after the birth. By gel filtration, the enzyme in the supernatant was Mr 330,000, but the solubilized enzyme was Mr 430,000 in the presence of Triton X-100. By electrophoresis, the 2 enzyme fractions demonstrated a charge difference. The enzymes showed the same pH optima of around 8.1 and 7.7, and Km values of 2.6 and 0.11 mm for Hip-His-Leu and angiotensin I, respectively. Sensitivity to known inhibitors and heat stability of the enzymes in 2 fractions were similar. In the human, 56% of the activity in skin homogenates (1.5 mU/mg) appeared in this supernatant and 44% in the pellet. Both soluble and solubilized preparations showed enzyme activity with 2 different molecular weights, 330,000 and 430,000. The human enzymes had chemical properties similar to the mouse enzymes, but their affinity for Hip-His-Leu and angiotensin I were 1.6 and 2 times higher than those of the mouse enzymes.

Aging↗
PubMed1982

Tissue angiotensin-converting enzyme and lysosomal enzyme levels in skin diseases.

The activities of tissue angiotensin-converting enzyme (ACE) were investigated in several skin diseases. Biopsy specimens were taken from 49 patients with granulomatous lesions, including sarcoidosis, 16 patients with nongranulomatous lesions, and 13 normal individuals. The ACE level was measured fluorometrically and the lysosomal enzyme levels were measured by established techniques. It was found that ACE activity increased in all granulomatous skin lesions, but not in other inflammatory lesions. The enzyme activity showed an increase that paralleled the time course of the disease. In contrast, lysosomal enzymes increased in various types of skin lesions, suggesting that they reflect nonspecific inflammation. These findings indicate that the tissue ACE level may be a marker for granulomatous inflammation, but one that is not specific for sarcoidosis.

Acid Phosphatase↗
PubMed1981

Studies of heterogeneity of angiotensin-converting enzyme and acid phosphatase in granulomatous lesions of skin.

Activities of angiotensin-converting enzyme and acid phosphatase were markedly elevated in the lesions of metal-induced hypersensitivity and foreign body types of granulomas. We biochemically studied these enzymes by means of gel filtration and electrophoresis and compared them with the same enzymes of normal dermis. Two forms of angiotensin-converting enzyme found in normal dermis were increased proportionally. Catalytic properties and heat stability of the enzyme in the lesions and normal dermis were the same. On the other hand, acid phosphatase in the lesions showed a different isozyme pattern from that seen in normal dermis. The enzyme from normal dermis had apparent molecular weight of 150000 and 90000, whereas an additional enzyme with a molecular weight of 230000 was detected in granulomatous lesions. Three isozymes were demonstrable in normal dermis but two additional isoenzymes appeared in granulomatous lesions: the isozyme patterns between the foreign body and hypersensitivity granulomas are different.

Acid Phosphatase↗
PubMed1981

X-ray analysis of a [2Fe-2S] ferrodoxin from Spirulina platensis. Main chain fold and location of side chains at 2.5 A resolution.

A [2Fe-2S] ferrodoxin from Spirulina platensis crystallized in space group C2221 with cell dimensions of a = 62.32, b = 28.51, c = 108.08 A, and alpha = beta = gamma = 90.0 degrees. X-ray structure analysis of the protein was carried out at 2.5 A resolution by the single isomorphous replacement method coupled with the derivative and the native anomalous dispersion methods. Phase angles of 2182 independent reflections were determined and their average figure of merit was 0.58. Each of 98 residues was superposed on the electron density sections enlarged to 2 cm/l A with a half-mirror device (Richards box). About 25% of the total residues form beta-structure and 10% fold in a tow-turn alpha-helix. A beta-barrel-like structure was found in the main chain fold. A polypeptide segment from residues 41 to 49 forms a loop structure outside the barrel. Two iron atoms of the [2Fe-2S] cluster are coordinated by three cysteines in the loop and by Cys-79. Hydrogen bonds of NH....S and OH....S stabilize the loop conformation. Most side chains are reasonably oriented in the molecule. The internal volume of the barrel is occupied by aliphatic nonpolar residues. All the charged groups are accessible to solvent molecules.

Binding Sites↗
PubMed1981

Effects of hyaluronidase and neuraminidase on immunoreactivity histidine-rich protein in newborn rat epidermis.

Frozen sections of newborn rat skin were treated with a variety of buffers, enzymes, and proteinase inhibitors in order to modify the reactivity of antigenic sites of histidine-rich protein and keratin. By indirect immunofluorescence, we found that antiserum to histidine-rich protein purified from granular cells reacted with keratohyalin granules but not cornified cells treated with hyaluronidase. The same antiserum reacted less distinctly with keratohyalin granules treated with neuraminidase; in contrast, it showed strong reactivity in cornified cells after the neuraminidase digestion. However, the enzyme digestions did not unmask the antigenic site(s) of keratohyalin granules to anti-keratin serum, as did saline in 0.1 M Tris-HCl buffer, pH 8.0. These results suggest that the antigenic site of histidine-rich protein is masked in keratohyalin granules by different mechanisms from the masking of keratin. Histindine-rich protein may be masked primarily with hyaluronic acid in keratohyalin granules, but the sugar moiety appears to be changed to sialic acid in cornified cells.

Animals↗
PubMed1981

Effects of 4-tertiary butyl catechol on melanocytes of hairless mice.

Depigmentary effects of 4-tertiary butyl catechol (TBC) on UV-stimulated melanocytes on the flanks and naturally active melanocytes of ears were compared in Uscd strain hairless mice. UVB irradiation, twice a week for 1 or 2 mo, induced brown-black pigmentation on the flanks. A 1 M TBC application twice a week for 1 mo not only prevented the UV-stimulated pigmentation, but also promoted fading of the post-UV tanning. Dopa-stained split epidermal sheets showed a decrease in the number of melanocytes to less than one-half during the first month of TBC treatment. Melanocytes were often enlarged or lost their dendrites, and both premelanosomes and melanosomes showed ultrastructural changes. However, TBC application on the ears for 1 mo showed neither color change nor a decrease in the number of melanocytes. There were ultrastructural changes in melanocytes but the degree of abnormality was much less than those seen in UV-stimulated melanocytes. Continuation of TBC application for 2 mo with the UV irradiation on the flanks or the nonirradiated ears caused an increase in the number of melanocytes. These results suggest that the initial effect of TBC may be primarily cytotoxicity to melanocytes, and may correlate with their cellular functions. The stimulatory effects of TBC on melanocytes seen during the longer period of time requires further investigation.

Animals↗
PubMed1981

Effects of glutaraldehyde and osmium tetroxide on newborn rat epidermal keratin.

The effects of glutaraldehyde and osmium tetroxide (OsO4) fixation on ultrastructural and biochemical changes of epidermal keratin were investigated. Morphometrically, the apparent size of keratohyalin granules was smallest when granular cells were fixed with OsO4, whereas those fixed with glutaraldehyde were larger, and those double-fixed with glutaraldehyde and OsO4 were largest. The ultrastructure of tonofilaments appeared different in each type of fixation. Biochemically, cross-linking glutaraldehyde with purified keratin from cornified cells formed a high molecular weight product with a blue shift of the absorption maximum and an increase in absorbance. Detection of the absorption spectra of OsO4- keratin reactions revealed that a new absorption maximum around 410 nm developed in glutaraldehyde-treated keratin, while one around 315 nm appeared in nontreated keratin. In addition, glutaraldehyde pretreatment increased by 40% the initial reaction rate and by 23% the total amount of OsO4 reduction. Sodium dodecyl sulfate gel electrophoresis demonstrated that degradation of keratin molecules occurred in both glutaraldehyde-treated and untreated keratin after 2 hr of exposure to OsO4. These findings indicate that keratin molecules are chemically modified by fixatives routinely used for electron microscopy. We consider that this chemical information plays an essential role in the appropriate interpretation of the ultrastructure of epidermal cells.

Aldehydes↗
PubMed1980

Chemical characterization, synthesis and distribution of proteinase inhibitor in newborn rat epidermis.

A protein solubilized in Tris-HCl/saline buffer from keratinized cells of newborn rat epidermis exhibited inhibitor activity to papain and ficin, but not to trypsin, cathepsin D and pepsin. This protein was purified from keratinized cells as well as nonkeratinized and germinative cells by means of IgG affinity chromatography. The inhibitors extracted from all cell layers were immunologically identical and had a molecular weight of approximately 12,500 +/- 500. Since amino acid analysis showed that the inhibitor contains about 35 residues of glycine per mol, [3H]glycine was used to investigate synthesis of the protein. The inhibitor from nonkeratinized and germinative cells was radioactively labeled by 2 h after injection and appeared in keratinized cells by 48 h after injection. Indirect immunofluorescence microscopy demonstrated in situ distribution of the protein in the entire epidermis, and the protein localized by the plasma membrane in granular cells and diffusely in keratinized cells was shown to be insoluble in Tris-HCl saline buffer. The results indicate that a thiol-proteinase inhibitor is synthesized in epidermal cells during keratinization and is retained as part of the cytoplasmic structure

Amino Acids↗
PubMed1980

Light-scattering studies of cation-stimulated filament assembly of newborn rat epidermal keratin.

Effects of CaCl2 on in vitro polymerization of keratin extracted from cornified cells of newborn rat were investigated by means of light-scattering and supramolecular structures. Elongation and parallel assembly of filaments occurred with addition of CaCl2 to dialyzed keratin solutions and was detected by an increase in light-scattering intensity. Nonfibrous aggregates which occurred in higher buffer concentrations and in lower pH were also recorded as intensity increased. MgCl2, ZnCl2, and GdCl3 demonstrated similar effects, but NaCl and KCl showed no effect.

Animals↗