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Biomedical subjects

M Hiruma

Publications and source records attributed to M Hiruma.

At least 55 records · Page 3Linked to original sources

Cathepsin B and D expression in squamous cell carcinoma.

To elucidate involvement of proteinases in malignancy of keratinocytes, expression of cathepsin B, a cysteine proteinase, and cathepsin D, an aspartic proteinase, was ascertained in formalin-fixed paraffin-embedded specimens of normal skin, squamous cell carcinoma (SCC). Bowen's disease, seborrhoeic keratosis and basal cell carcinoma (BCC). Presence of procathepsin B and an intermediate form of cathepsin D was confirmed by Western blotting and enzyme activity analysis. Cathepsin B stained more intensely in SCC tumour cells than in normal epidermis; staining patterns were diffuse, granular or both. Diffuse and granular patterns (procathepsin B and mature enzyme, respectively) appeared in inner and outer parts of tumour islands, respectively. Five of 20 cases of Bowen's disease showed diffuse enhanced cathepsin B expression; 20 cases of seborrhoeic keratosis or BCC did not. Cathepsin D stained intensely in tumour cells of half the SCC cases. The staining manner and distribution of cathepsins B and D was similar in the cytoplasm of cancer cells. No enhanced staining of cathepsin D was seen in any cases of Bowen's disease, seborrhoeic keratosis, or BCC. Coexistence and localization of active mature forms of cathepsins B and D suggests that cooperation between the two enzymes may play an important part in invasion of SCC.

Blotting, Western↗

Prurigo pigmentosa, ketonemia and diabetes mellitus.

The etiology of prurigo pigmentosa still remains unknown. We present a 16-year-old female patient with ketonemia caused by diabetes mellitus. The eruption subsided when blood glucose and total ketone levels were controlled by subcutaneous insulin injection. We propose that ketonemia caused by diabetes mellitus may play a role in the pathogenesis of prurigo pigmentosa.

Adolescent↗

Photosensitivity induced by fleroxacin.

A case of photosensitivity induced by fleroxacin (FLRX) is reported. A 71-year-old man had erythema on sun-exposed areas after 5 months FLRX treatment for prostatitis. The minimal erythema dose to UVA was reduced at the initial examination and became normal 4 weeks after he stopped taking FLRX. Oral photo-challenge with FLRX 100 mg was positive, but photopatch testing was negative. Fleroxacin (FLRX), in use since 1992, is a fluoroquinolone antibacterial derived from quinoline. Photosensitivity induced by FLRX is not uncommon, but a photobiological study has not been reported. The mechanism of action of photosensitivity induced by the fluoroquinolones is considered to be phototoxic in origin in that in vitro technique studies are positive. FLRX, a quinoline derivative may be a photosensitizer as well as enoxacin, lomefloxacin and sparfloxacin.

Aged↗

Detection of varicella-zoster virus DNA in maternal breast milk from a mother with herpes zoster.

BACKGROUND: We previously reported that varicella-zoster virus (VZV) DNA was detected by polymerase chain reaction (PCR) from maternal breast milk of a post-partum mother with chickenpox. OBJECTIVES: We tried to decide the route of VZV contamination to maternal milk. CASE REPORT: A 22-year-old woman developed herpes zoster on her right Th3-4 dermatome. RESULTS AND CONCLUSIONS: VZV DNA was detected by PCR from peripheral blood and the maternal milk of the right breast, but not from the maternal milk of the left breast. These results suggest that VZV in maternal milk may not derive from VZV-infected mononuclear cells in peripheral blood, but from the VZV-infected epitheliums of the lacteal gland.

Journal Article↗

Rat epidermal cathepsin B: purification and characterization of proteolytic properties toward filaggrin and synthetic substrates.

The aim of this study was to purify epidermal cathepsin B from rat skin and investigate its proteolytic activities on filaggrin and several synthetic substrates. The molecular weight of purified monomeric cathepsin B was estimated to be 30 kDa by SDS-polyacrylamide gel electrophoresis. The amino acid composition, similar to that of liver cathepsin B, indicated the enzyme to be an acidic protease. The enzyme had strong hydrolytic activity toward N-benzyloxy-carbonyl-L-arginyl-L-arginine-7-amido-4-methylcoumarin (Z-Arg-Arg-MCA) (152 mU/mg) and N-benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amido-4-methylcoumarin (424 mU/mg), but had no proteolytic activity toward L-arginine-7-amido-4-methylcoumarin. The Km value for Z-Arg-Arg MCA was 0.34 mM and pH optimum was 5.5. Cathepsin B degraded rat epidermal filaggrin into small fragments at pH 4.0 and 5.5., and was inhibited by a specific cysteine proteinase inhibitor, N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)L-leucyl]- agmatin. This study demonstrated that filaggrin was susceptible to degradation by cathepsin B. Such an action may have relevance to skin differentiation in which acid proteases are thought to participate.

Animals↗

Rat epidermal cathepsin L-like proteinase: purification and some hydrolytic properties toward filaggrin and synthetic substrates.

We have purified cathepsin L-like proteinase from rat epidermis, determined its NH2-terminal amino acid sequence, and investigated its proteolytic activities on an intermediate filament-associated protein filaggrin and several synthetic substrates. The amino acid sequence of its NH2-terminus was determined to be Val-Pro-Asn-Ser-Leu-Asp-Trp-Arg-Glu-Lys-Gly-Tyr-Val-Thr-Pro-, which differed from that of rat cathepsin L and was not found in the amino acid sequence data bank. The enzyme consisted of a single-chain form with M(r) 30,000. Its hydrolytic properties toward synthetic substrates were similar to those of cathepsin L in other tissues. The enzyme effectively proteolyzed rat epidermal filaggrin into small fragments at pH 4.0-6.0 and was inhibited by a specific cysteine proteinase inhibitor, N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)L-leucyl]-agmatin. However, cathepsins D and E from rat epidermis did not hydrolyze filaggrin. This study demonstrated that filaggrin was susceptible to degradation by rat epidermal cathepsin L-like proteinase, suggesting that this proteolytic activity may have relevance to skin differentiation, in which acid proteases are thought to participate.

Amino Acid Sequence↗

Exanthem subitum (roseola infantum) with vesicular lesions.

We report a 7-month-old boy who developed vesicular lesions during the course of exanthem subitum. Human herpesvirus-6 (HHV-6) DNA was detected both in the skin lesions and in the throat, by polymerase chain reaction. IgG and IgM antibodies against HHV-6 were 1:10 and < 1:10, respectively on the tenth day of the illness, and > 1:640 and 1:10 on the twenty-second day, respectively. These results suggest that this was primary HHV-6 infection.

Antibodies, Viral↗

A new approach to the evaluation of broad-spectrum sunscreens against ultraviolet and visible light-induced delayed tanning.

Protection against UV and visible light-induced delayed tanning (DT) and immediate tanning (IT) of two broad-spectrum sunscreens with the same sun protection factor was investigated. Protection factors (PFs) against DT (24 h and 7 days) of the sunscreens differed significantly, but PFs against IT did not. This study indicates that using PF against 24 h DT is more appropriate for an evaluation of broad-spectrum sunscreens against UVA and visible light than IT.

Adult↗