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Biomedical subjects

H Tagami

Publications and source records attributed to H Tagami.

At least 343 records · Page 19Linked to original sources

Role of complement in chlorpromazine-induced phototoxicity.

To evaluate the role of the complement system in inflammation induced by chlorpromazine (CPZ) and ultraviolet-A (UVA) irradiation, the phototoxic response in guinea pigs decomplemented by cobra venom factor was compared with that in saline-treated animals. Phototoxic lesions were induced in animals by intradermal injections of CPZ solution, followed by UVA irradiation. Clinically, the normal animals developed erythema and induration which showed a maximal response at 10 h with a mean value of 1.6 on a scale of 0 to 3+. The complement-depleted animals showed a weaker clinical response than the normal animals 6-24 h postirradiation (p less than 0.05). These clinical changes were associated with increased vascular permeability, as demonstrated by extravasation of i.v. injected Evans blue in saline-treated animals. In vitro UVA irradiation of serum containing CPZ resulted in a dose-dependent diminution of total complement activity. Such irradiated serum showed immunoelectrophoretic C3 conversion. These results suggest that the complement system is involved in the development of CPZ-induced phototoxic lesions.

Animals↗

Hydration characteristics of pathologic stratum corneum--evaluation of bound water.

We measured in vitro the hygroscopicity and bound (non-freezing) water of various samples of pathologic horny layer obtained from the lesions of senile xerotic skin and psoriasis vulgaris and the normal horny layer from glabrous skin and plantar horny layer. The amount of water taken up by pathologic stratum corneum was much smaller than that by normal horny layer in an environment at a high relative humidity (RH). Tightly bound primary water to stratum corneum measured by Karl Fischer's method was about 5 mg/100 mg of dry stratum corneum in all the samples studied, while less tightly bound secondary water was much smaller in amount in pathologic stratum corneum than in the controls, i.e., 31.7 mg/100 mg dry scale from senile xerosis and 27.2 mg/100 mg dry psoriatic scale as compared with 38.2 mg/100 mg dry normal stratum corneum from glabrous skin and 37.3 mg/100 mg dry normal plantar stratum corneum. We believe that the low hygroscopicity of the pathologic stratum corneum is due to this smaller capacity for secondary bound water, which is responsible for the development of a dry scaly appearance even at high RH.

Adult↗

Determination of anaphylatoxin concentrations in suction blisters in patients with psoriasis.

Concentrations of C3a and C4a anaphylatoxins in suction blister fluids were determined by radioimmunoassay in patients with psoriasis and normal controls. Comparison of anaphylatoxin levels between serum samples and blister contents in the same subjects revealed that the levels of both C3a and C4a anaphylatoxins were significantly higher in the former than the latter even in those raised on normal skin, suggesting that the classic complement pathway is activated during suction procedure. Therefore we cannot regard suction blister fluid to be simply representative of undisturbed interstitial tissue fluid as far as the complement system is concerned. There was no difference in anaphylatoxin levels between those from uninvolved skin of psoriatic patients and those from normal controls. However, significantly high anaphylatoxin levels were noted in fluids of suction blisters raised on lesional skin as compared with those produced on uninvolved skin in psoriatic patients.

Adolescent↗

Demonstration of anaphylatoxins C3a, C4a and C5a in the scales of psoriasis and inflammatory pustular dermatoses.

Complement components C3a, C4a and C5a were assayed in corneal scale extracts from psoriasis and other dermatoses characterized by sterile subcorneal pustules, using radioimmunoassay. Larger amounts were detected in psoriasis and related pustular dermatoses than in extracts of non-inflammatory stratum corneum. It is concluded that complement is activated via the classical pathway and releases the neutrophil chemotactic fragment C5a.

Anaphylatoxins↗

Eosinophilic pustular folliculitis. Studies on possible chemotactic factors involved in the formation of pustules.

Eosinophilic pustular folliculitis (EPF) is a dermatosis of unknown aetiology, characterized by repeated development of pruritic follicular papulopustules with a tendency to form an annular configuration on the face and other seborrhoeic areas, and by palmoplantar pustular lesions in one-fifth of the patients. Both types of lesions are infiltrated mainly by eosinophils with some polymorphonuclear leukocytes (PMN). To elucidate the mechanisms underlying pustule formation, we studied the chemotactic activity for leukocytes of the skin surface lipids (SSL) obtained from seborrhoeic areas. No specific chemotactic activity was detectable in stored SSL from patients with EPF. However, fresh SSL collected from the seborrhoeic areas of normal adults contained chemotactic substances for eosinophils and PMN which were labile on storage in air. In stratum corneum extracts from palmoplantar lesions of patients with EPF we demonstrated the presence of a 13000 molecular weight chemoattractant factor for PMN, the activity of which was partially inhibited by antiserum against C5a, and a low molecular weight lipid-soluble chemotactic factor for eosinophils, the activity of which was also lost on storage in air. Our findings suggest that these chemotactic factors play a role in the production of the characteristic pustular lesions of EPF.

Adult↗

Incontinentia pigmenti: eosinophil chemotactic activity of the crusted scales in the vesiculobullous stage.

To investigate the mechanisms underlying eosinophil infiltration into the epidermis in incontinentia pigmenti (IP), we studied the eosinophil chemotactic activity in extracts of the crusted scales from three patients with IP in the vesiculobullous stage. Eosinophil chemotactic activity was detected in the eluates from a Sephadex G-75 chromatography column between the vitamin B12 and phenol red markers. The chemotactic activity was heat-stable and resistant to enzyme digestion, and recovered after ether extraction at low pH. Leukotriene B4 (LTB4) was demonstrated in the fractions with high eosinophil chemotactic activity. These findings suggest that LTB4 plays an important role in the accumulation of eosinophils within the epidermis in IP, in the vesiculobullous stage. Blood eosinophilia, however, may not be induced by the eosinophil chemotactic factors in the scales.

Chemotactic Factors↗

Successful treatment of psoriasis with topical application of active vitamin D3 analogue, 1 alpha,24-dihydroxycholecalciferol.

We treated 11 psoriatic patients with topical 1 alpha,24-dihydroxycholecalciferol, a new synthetic analogue of active vitamin D3. In 10 of 15 tests the lesions cleared completely within 1-4 weeks, although some relapses occurred shortly after cessation of treatment. There were no side-effects. We suggest that 1 alpha, 24(OH)2D3 merits further investigation as a potentially useful topical therapy for psoriasis.

Adolescent↗

Immunohistochemical studies on epithelial cells in mixed tumor of the skin.

We performed studies on the lectin-binding pattern in epithelial tumor cell components of 4 cases of mixed tumor of the skin developing on the face in addition to identification of keratin and carcinoembryonic antigen (CEA), compared with those of normal sweat glands. Normal eccrine glands showed specific labelling with Dolichos biflorus agglutinin (DBA) and soybean agglutinin (SBA), whereas none of the studied lectins reacted specifically with normal apocrine glands. In mixed tumors the dark cells, which form the inner layer of the tubuloalveolar and ductal structure, showed the presence of keratin and CEA, as well as of specific sugar structures that bind to DBA and SBA. On the other hand the light cells that form the outer layer of the tubular structures or the solid epithelial cell nests gave only a faint to moderate staining of keratin, and no staining of CEA or lectins. It is probable that the inner dark cells differentiate toward the cells that have the same sugar structures on the cell surface as those of the normal eccrine gland cells, while the outer light cells appear to be immature or in a less differentiated state.

Adult↗

New primary malignant melanoma, epidermotropism and Indian-file arrangement of metastatic tumor cells in a case with intransit metastases of acral type of malignant melanoma.

Multiple malignant melanocytic lesions developed on a localized area of the thigh in an 80-year-old woman 3 years after excision of a primary malignant melanoma on the left second toe and dissection of left inguinal lymph nodes. Biopsy specimens obtained from 2 small pigmented macules revealed the histologic features of new primary lesions, simulating that of the primary lesion on the toe; no tumor cells were found within vessel lumina. A brown-black papule neighboring one of the macules histologically resembled compound type of melanocytic nevus, but the tumor cells compressed thinned epidermis with focal epidermotropism. Other papules, whose color ranged from light brown to reddish brown, showed metastatic tumor cells only in the dermis. In 3 of them, individual tumor cells were lined up along the collagen bundles, showing an 'Indian-file' arrangement. Such a combination of various histologic features in a case of intransit metastases of acral type of melanoma has not been reported in the literature.

Aged↗

Solar urticaria without inhibitory spectrum: demonstration of both circulating photoallergen and reaginic antibodies.

An 18-year-old man with solar urticaria is described. The action spectrum ranged from 400 to 500 nm. No inhibition spectrum was found, i.e., the wheal that is induced by visible light was not inhibited by immediate pre- or postirradiation of test sites with light waves longer than 620 nm. The patient developed a wheal at the site of injection of his own serum that had previously been exposed to light in vitro. Though the ordinary passive transfer reaction yielded a positive result, a passive transfer study with the patient's serum preheated at 56 degrees C for 2 h showed a negative result. These data suggest that he had both circulating photoallergen and reaginic antibodies.

Adolescent↗

Interleukin-1-like activity in horny layer extracts: decreased activity in scale extracts of psoriasis and sterile pustular dermatoses.

Interleukin-1 (IL-1)-like activity was assessed in scale extracts prepared from skin specimens from 36 cases of psoriasis and other dermatoses characterized by the formation of sterile subcorneal pustules. IL-1 activity was detected in only 2 samples. In contrast, much higher IL-1 activity was demonstrated in horny tissue extracts prepared either from normal skin or from noninflammatory skin such as plantar callus, scar or ichthyosis. No correlation was found between neutrophil chemotactic activity and IL-1 activity demonstrable in horny tissue extracts.

Callosities↗

Effect of interleukin 1 on chemotaxis and chemiluminescence of human neutrophils.

We studied the influence of interleukin 1 (IL 1) on chemotaxis and chemiluminescence (CL) of human neutrophils. We found that IL 1 showed chemotactic activity within the concentrations ranging from 1 to 200 U/ml, whereas no luminol-or lucigenin-dependent CL was noted in neutrophils with the stimulation of IL 1 at the concentrations ranged from 1 to 100 U/ml. Moreover, no enhancement of zymosan-induced CL was observed in neutrophils following prior exposure to IL 1 at a concentration of 100 U/ml for 60 min at 37 degrees C. We think that IL 1 may be responsible for the inflammatory reaction only through its chemotactic activity for neutrophils without enhancement of the oxidative metabolism of neutrophils.

Acridines↗

Stimulation of melanogenesis by cholecalciferol in cultured human melanocytes: a possible mechanism underlying pigmentation after ultraviolet irradiation.

An increase in the amount of tyrosinase was demonstrated in the cultured human melanocyte after 6-day culturing with cholecalciferol (vitamin D3) by increased intensity of the immunofluorescent staining using monoclonal antibody against tyrosinase. Furthermore, the melanocytes became more dendritic as noted in those in the skin after the irradiation of ultraviolet. However, 7-dehydrocholesterol (pro-vitamin D3) or 1 alpha, 25-dihydroxy-vitamin D3 (activated vitamin D3) did not induce any such effect on the cultured human melanocytes. Since cholecalciferol is known to be photo-chemically converted by the ultraviolet irradiation from pro-vitamin D3 produced in the skin, the so-far-unknown mechanism of human skin pigmentation after the ultraviolet irradiation may be partly explained by this stimulating effect of vitamin D3 on the melanocytes.

Cells, Cultured↗

Demonstration of leukotriene B4 in the scale extracts of psoriasis and inflammatory pustular dermatoses. Correlation with leukocyte chemotactic activity and C5a anaphylatoxin.

We carried out quantification of the levels of leukotriene B4 (LTB4), a highly potent cell membrane-derived leukocyte chemotactic factor, in scale extracts of psoriasis and related inflammatory dermatoses characterized by sterile subcorneal pustule formation by using radioimmunoassay. A small amount of LTB4 was demonstrable even in extracts from non-inflammatory stratum corneum, but larger amounts were detected in the scale extract from pustular psoriasis and in those from psoriasis vulgaris. There was a significant correlation between the LTB4 and C5a levels in scale extracts, suggesting that complement activation and generation of LTB4 are a closely related event in psoriatic lesions. However, in contrast to highly significant correlation noted between the amount of C5a and chemotactic activity for polymorphonuclear leukocytes (PMN) detectable in scale extracts, LTB4 levels correlated only marginally with the chemotactic activity.

Chemotaxis, Leukocyte↗