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Biomedical subjects

R Hayakawa

Publications and source records attributed to R Hayakawa.

At least 37 records · Page 2Linked to original sources
PubMed1997

Immunosuppression by ultraviolet B rays via eyes in mice.

Irradiation by ultraviolet B (UV-B; 280-320 nm) initiates suppression of contact hypersensitivity. Immunosuppression was induced in C57BL/6N Crj mice by exposure of the dorsal skin or the eyes to a 10 kJ/m2 dose of UV-B radiation from 20SE sunlamps, followed by sensitization with 0.5% fluorescein isothiocyanate (FITC). The degree of immunosuppression induced by UV-B eye irradiation was equal to that induced by UV-B skin irradiation. When mice were irradiated with UV-B into the eyes after the optic nerve had been cut, systemic immunosuppression was not induced.

Animals↗
PubMed1997

Proposal for a revised international standard series of patch tests.

Worldwide, there are 3 major standard series of patch tests, the European, North American and Japanese, together presenting 32 allergens, the differences between them being the result of regional variation in allergen distribution as well as differences in dermatological opinion. We propose a "minimal" international standard series of 20 allergens, together with an "extended" international standard series of 14 allergens.

Dermatitis, Contact↗
PubMed1997

A genomic study on the cultivable and nerve invading Mycobacterium HI-75 after the recovery 3 months of the inoculation to nude mice.

The sequence of the polymerase chain reaction (PCR) product of 16S ribosomal RNA (16S rRNA) of the leproma-derived and cultivable Mycobacterium HI-75 (M. HI-75) which was obtained from the infected regions of inoculated mice, was examined and compared with that of the cultured bacteria by the direct sequencing techniques. The sequence was completely consistent with the cultured bacilli in the comparable 837 bases of 16S rRNA. The mycobacterium examined in this study was originally isolated as M. leprae (ML) by Skinsnes, et al. in 1975 from leproma of a lepromatous type Hansen's disease patient and therefore named as Mycobacterium leprae HI-75 by them, and was maintained from 1984 using either Ogawa's or Sauton's media in the beginning and Ogawa's medium enriched with glucronic acid and N-acetyl-D-glucosamine recently. Sasaki and Hamit reported the nerve invasion and the growth of the inoculated bacilli either to the nude mice or the I131 treated immunocompromised Swiss mice. We previously reported that cultured HI-75 was most similar to M. scrofulaceum by the direct sequencing of the gene of 16S rRNA. The 16S rRNA obtained from the mouse tissue in the present study indicated that M. HI-75 would be a variant of M. scrofulaceum possessing an ability to invade into peripheral nerve. The results suggest that the HI-75 strain claims a nature as a pathogen to develop a leproma-like lesion.

Animals↗
PubMed1996

Different T-cell receptor repertoires between lesions and peripheral blood in acute graft-versus-host disease after allogeneic bone marrow transplantation.

From the viewpoint of T-cell receptor (TCR) repertoire, we studied the role of T cells in acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT) from an HLA-identical sibling. By means of inverse polymerase chain reaction method and DNA sequencing, we analyzed TCR-alpha and -beta transcripts from GVHD lesions and peripheral blood (PB) in a patient with typical GVHD together with PB from donor. At the initial onset of GVHD, V alpha-7 and -19 subfamilies were oligoclonally expanded in the PB compared with those in the oral mucosal lesions. At the second onset, V alpha-2, and V beta-6 subfamilies were more frequently detected in the cutaneous lesion than in the PB. Some TCR transcripts were recurrently found either in the mucosal or cutaneous lesions (or in both) and not in the PB. Furthermore, some of recurrent TCR transcripts in the lesions shared V gene segments and common motifs of complementarity determining region-3. These findings suggested that T cells infiltrating the GVHD lesions recognized a limited kind of antigens presented by patient's tissues with GVHD, and that T-cell repertoire in the GVHD lesions was different from that in the PB.

Acute Disease↗
PubMed1996

Establishment of an in vitro cell derived from human angiosarcoma.

We have succeeded in the establishment of a human endothelial cell line derived from a human angiosarcoma. These cells grew as monolayers with a "cobble stone" morphology. The cells produced endothelin and showed Weibel-Palade bodies in their cytoplasm. These findings show that the cells have specific differenciated functions, and might be useful for both fundamental endothelial cell biology and biological investigation of angiosarcoma.

Aged↗
PubMed1994

Identification of causative chemicals of allergic contact dermatitis using a combination of patch testing in patients and chemical analysis. Application to cases from industrial rubber products.

3 cases of allergic contact dermatitis from industrial rubber products were investigated using a combination of patch testing in patients and chemical analysis of causative rubber products by gas chromatography (GC), GC-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). Our studies revealed N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), a typical rubber allergen, as a causative chemical in a case from a brand of heavy-duty rubber gloves and a case from a black rubber ring for car manufacture, and zinc ethylphenyldithiocarbamate (ZEPC), a dithiocarbamate (DTC)-type accelerator, as a causative chemical in a case from a brand of rubber work gloves: both IPPD and ZEPC, which showed positive patch test reactions, were confirmed in the extracts of the causative rubber products by GC, GC-MS and/or HPLC.

Adult↗
PubMed1993

Fixed drug eruption due to allylisopropylacetylurea.

We report a case of fixed drug eruption due to allylisopropylacetylurea. A 21-year-old female developed purplish-red round eruptions on her neck and left thigh after taking an analgesic containing isopropylantipyrine, allylisopropylacetylurea, phenacetin and anhydrous caffeine. Patch testing with the analgesic and its ingredients on the eruptive area showed positive reactions to the analgesic and allylisopropylacetylurea, while patch testing on the non-eruptive area showed negative reactions. We diagnosed her condition as a fixed drug eruption due to allylisopropylacetylurea in an analgesic.

Adult↗
PubMed1992

Tinuvin P in a spandex tape as a cause of clothing dermatitis.

We report a 54-year-old female with allergic contact dermatitis from 2-(2-hydroxy-5-methylphenyl)benzotriazole (Tinuvin P) in a spandex tape sewn into underwear. Tinuvin P is used as an ultraviolet light absorber for stabilizing plastics and the other organic materials against discoloration and deterioration. It is effective in protecting synthetic and natural fibers, polyesters, chlorinated polyesters, polystyrene, polyvinyls, cellulose acetate, ethyl cellulose, acrylates, dyes, waxes, detergents, cosmetic formulations, etc. Our patient developed itchy erythema on her shoulders, chest and upper back after wearing underwear for 1 night. She showed positive reactions to spandex tape sewn into the underwear. She also reacted to 2-(2-hydroxy-5-methylphenyl)benzotriazole (Tinuvin P), which was contained in the spandex. No cross-reaction to other benzotriazoles was seen.

Chromatography, Gel↗
PubMed1991

Pigmented contact dermatitis due to musk moskene.

Musk moskene is a soft, sweet fragrance resembling musk ambrette which introduces a very desirable creamy powder note for cosmetic fragrance. Because of its advantages, which include low cost, oil solubility, and less sensitive to sunlight, musk moskene has recently increased its share of the market. In this paper, we reported a case with pigmented contact dermatitis from musk moskene in cheek rouges. Patch test positive reactions to cheek rouges resulted in hyperpigmentation. Both the perfume used in the cheek rouges and musk moskene, which was a component of that perfume, showed strongly positive reactions. Residual hyperpigmentation was seen on the regions of the perfume and musk moskene patch testings. Hyperpigmentation on cheeks of the patient gradually diminished after discontinuing use of the causative cheek rouge.

Adult↗
PubMed1991

Identification of contact allergens in C.I. Solvent Red 23 (commercial Sudan III) by chemical analysis and animal testing.

C.I. Solvent Red 23, commercial Sudan III, is widely used in cosmetic products. Chemical analyses and guinea pig sensitization tests were carried out to identify its contact allergens. In the Magnusson & Kligman guinea pig maximization test, C.I. Solvent Red 23 showed 20% positive reactions. By conducting chemical analyses with HPLC and GLC, 2-naphthol (82 ppm), azobenzene (48 ppm), Sudan I (570 ppm) and many unknown impurities, as well as the main constituent pigment Sudan III (87%), were found. The chemical structure of one unknown impurity was identified as an isomer of Sudan III. We found that purified Sudan III showed no positive reaction, while the isomer elicited 30% positive reactions, in the same guinea pig test. Furthermore, cross-sensitization with p-phenylenediamine was investigated using the guinea pig test. Animals sensitized with p-phenylenediamine also showed positive elicitation reactions with purified Sudan III. From these results, the contact allergenicity of C.I. Solvent Red 23 is considered to be due to impurities, including the isomer of Sudan III, 1-(o-phenylazophenylazo)-2-naphthol. Positive reactions to Sudan III previously demonstrated in hairdressers are due to cross-sensitivity with p-phenylenediamine.

Allergens↗