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Biomedical subjects

H Tagami

Publications and source records attributed to H Tagami.

At least 415 records · Page 23Linked to original sources
PubMed1983

Texture of the skin graft, with special reference to the hydration state of the stratum corneum.

The water contained in the superficial portion of the stratum corneum plays an important role in keeping the skin surface soft and smooth. In an attempt to study the true nature of the "texture" of grafted skin, in vivo water sorption-desorption tests were performed on grafts, on normal skin adjacent to grafts, and on normal skin surrounding the donor sites. The results showed that skin grafted to sites other than the face maintained a functional similarity to normal skin surrounding the donor site. However, in skin grafted to the face, the functions of the stratum corneum, as measured in terms of hydration state, increased, and this was associated with an improved water-holding capacity that probably results from the effect of abundant sebum and sweat excretion in adjacent skin. From these results it is suggested that the recipient site plays an important role in determining the difference in the function of the stratum corneum, i.e., the "texture" between grafts on the face and those on other sites.

Adolescent↗
PubMed1983

Subcorneal pustular dermatosis with vesiculo-bullous eruption. Demonstration of subcorneal IgA deposits and a leukocyte chemotactic factor.

We report an unusual case of subcorneal pustular dermatosis with widespread vesiculobullous lesions. Reduction of the oral prednisone dosage provoked a severe exacerbation, with erythroderma associated with massive pustule formation. This was effectively controlled by topical PUVA. Subsequent recurrence of skin lesions responded well to oral etretinate. Investigation revealed intercellular IgA deposits at the upper epidermis of the paralesional skin, but no circulating antibodies were detected. Characterization of the chemotactic activity of the soluble components of the scales revealed the presence of a 12,000 molecular weight leukotactic factor resembling that found in psoriasis. Furthermore, the vesicle fluid showed only this chemotactic factor, indicating that it may be a major factor in the pathogenesis of subcorneal pustules.

Chemotactic Factors↗
PubMed1983

Atypical ("pseudosarcomatous") cutaneous histiocytoma.

We report a patient with a cytologically atypical hemosiderotic histiocytoma that histologically suggested a sarcoma. The lesion is differentiated from atypical fibroxanthoma and fibroxanthosarcoma. We wish to emphasize the benign nature of this variant of histiocytoma whose extreme cellular atypicality may simulate a sarcoma.

Culture Techniques↗
PubMed1983

Induction of leukocyte adherence at the basement membrane zone with subsequent activation of their metabolic pathway by pemphigoid antibodies and complement.

We observed in our in vitro studies that human leukocytes were attached by their complement receptors to the basement membrane zone (BMZ) of the skin specimens pretreated with pemphigoid antibodies and complement. The resultant histologic feature was very similar to that of an early stage of the inflammatory reactions observable in the lesions of bullous pemphigoid. Eosinophils were also attracted to the BMZ in proportion to their number in cell suspensions, but the adhesion of eosinophils occurred neither selectively nor excessively. The nitroblue tetrazolium (NBT) test, which was carried out after the leukocyte attachment test, demonstrated that only those leukocytes bound specifically to the BMZ incorporated NBT dye complexes vigorously to form formazan crystals in their cytoplasms. The present studies showed that complement-fixing anti-BMZ antibodies induce enhancement of leukocyte activities as well as immune adherence to the BMZ, indicating that the enhanced leukocyte function plays a role in the separation between epidermis and dermis in bullous pemphigoid.

Antibodies↗
PubMed1983

Pemphigus antibodies mediate the development of an inflammatory change in the epidermis. A possible mechanism underlying the feature of eosinophilic spongiosis.

The interaction between complement-fixing pemphigus antibodies and leukocytes was investigated by the in vitro leukocyte attachment test. Attachment of eosinophils as well as neutrophils was induced by pemphigus antibodies at the intercellular space of epidermis in the presence of complement. This phenomenon was found to be produced by 7 out of 10 pemphigus sera in the indirect method using non-lesional skin as a substrate, and in 2 out of 7 biopsy specimens taken from perilesional skin without addition of any sera by the direct method. Those leukocytes bound specifically to the epidermis showed an enhanced function. i.e., vigorous incorporation of nitroblue tetrazolium dye complexes and formation of formazan crystals in the cytoplasms. The results of the present studies suggest that complement-fixing pemphigus antibodies mediate the development of an inflammatory change by inducing an infiltration of polymorphs in the epidermis, which is noted as eosinophilic spongiosis histologically.

Antibodies↗
PubMed1983

Delayed hypersensitivity in ampicillin-induced toxic epidermal necrolysis.

A patient with ampicillin-induced toxic epidermal necrolysis (TEN) showed pronounced delayed hypersensitivity to ampicillin sodium by both intradermal and patch tests. In addition, a positive lymphocyte transformation test to ampicillin was demonstrated by an in vitro study. On the basis of these findings and the data found in the literature, we believe that delayed hypersensitivity plays a crucial role in the development of drug-induced TEN. We recommend patch testing with suspected medication in such cases.

Adult↗
PubMed1982

Analysis of transepidermal leukocyte chemotaxis in experimental dermatophytosis in guinea pigs.

In dermatophytosis, there is exocytosis of polymorphonuclear leukocytes (PMNs) toward the fungus-laden horny layer. To analyze this mechanism, we studied in vitro leukotactic properties of epidermal extracts prepared from lesions of experimental Trichophyton mentagrophytes infection in guinea pigs as well as fungus-derived chemotactic factors. Trichophyton mentagrophytes was found to release low-molecular-weight PMN chemotactic factors with its growth, like other microorganisms. Furthermore, it activated complement via the alternative pathway to produce complement-derived chemotactic factors in vitro. The epidermal extracts prepared from weakly inflammatory lesions of an early stage of T. mentagrophytes infection showed mild PMN chemotactic activity, which, as in those from irritated skin, was mostly due to the presence of low-molecular-weight chemotactic factors. After 8 days of infection, when prominent PMN migration took place together with the development of immune reactivity to fungus antigens, the epidermal extracts revealed strong leukotactic activity that showed a triphasic pattern by Sephadex G-75 chromatography similar to that observed in complement-activated serum. Since we could not demonstrate any deposition of immunoglobulins and complement on the fungal elements present in the horny layer, actual complement activation in vivo seems to occur after interaction of serum with soluble fungal components in the epidermis through both classic and alternative pathways. We think that the transepidermal migration of PMNs in dermatophytosis, together with contact sensitivity to fungal antigens, is responsible for induction of increased epidermopoiesis with resultant desquamation to eliminate the fungus-laden horny layer.

Animals↗
PubMed1982

Psoriatic leukotactic factor. Further physicochemical characterization and effect on the epidermal cells.

A leukocyte chemotactic factor with a molecular weight of around 12,500 daltons is found in large amounts in psoriatic scales. Except for complement-activated serum none of the extracts prepared from individual contaminants found in psoriatic scales showed an elution pattern similar to that of the psoriatic leukotactic factor (PLF) by Sephadex G-75 chromatography. Checkerboard experiments showed that PLF was highly chemotactic and mildly chemokinetic for polymorphonuclear leukocytes (PMNs). Purification of PLF yielded a cationic peptide fraction similar to that of anaphylatoxin. Intradermal injection of a potent PLF solution into guinea pigs produced degenerative changes in the epidermis within 24 h, particularly in the differentiated cells of the upper epidermis. It increased epidermopoiesis as assessed by incorporation of 3H-thymidine. Planimetric analysis of the epidermis revealed a marked increase in epidermal thickness after 5 days. Since PLF per se did not influence the proliferative capabilities of isolated basal cells or exert any damaging effect on differentiated epidermal cells in human epidermal cell culture, we speculated that PLF induced the advent of PMNs abound with hydrolytic enzymes and toxic substances, which were responsible for the damage of the upper epidermis resulting in the formation of parakeratosis and of acanthosis.

Animals↗
PubMed1982

Water sorption-desorption test of the skin in vivo for functional assessment of the stratum corneum.

Based on the evidence from our previous studies that we can evaluate the hydration state of the skin surface quickly and quantitatively in terms of conductance to the high frequency electric current of 3.5 MHz, we have established a simple in vivo function test that furnishes information on the hygroscopic property and water-holding capacity of the stratum corneum in a few minutes. The test procedure consists of electromeasurements before and after application of a droplet of water on the skin for 10 seconds to obtain data on the hygroscopic property of the skin surface and later serial measurements at an interval of 30 seconds for 2 min to evaluate the water-holding capacity. Under usual ambient conditions normal skin surface showed a high rise in conductance just after application of water, which was followed by a rapid fall-off within 30 seconds, thereafter by gradual return to the prehydration levels by 2 min. By this method we have demonstrated that (i) the superficial horny layer of normal skin is much less hygroscopic and less capable of holding water than the corresponding deeper portions and that (ii) scaly skin shows functional defects in both hygroscopicity and water-holding capacity, between which the former normalizes much faster than the latter.

Absorption↗