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Biomedical subjects

H Tagami

Publications and source records attributed to H Tagami.

At least 397 records · Page 22Linked to original sources
PubMed1984

Relation of clinical activity of rheumatoid arthritis to immune complexes, complement components and anti-immunoglobulins.

Circulating immune complexes by fluid phase Clq binding assay, complement components and anti-immunoglobulin levels were studied in sera of 35 patients with rheumatoid arthritis (RA). In 23 of the 35 sera (65.7%), circulating immune complexes were positive, and the mean +/- SD of Clq binding activity (ClqBA), 44.5 +/- 19.4%, was significantly high compared to that of healthy persons, 17.4 +/- 8.2%. Antigenic determination of complement components revealed that Clq, C3, C5, C9, factor B and Cl esterase inhibitor (ClINH) were significantly high in sera of RA, but C4 and properdin were not. The disease activity correlated with ClqBA, IgG- and IgM-anti-immunoglobulins, C9 and serum IgG. On the other hand, ClqBA correlated with both IgG- and IgM-anti-immunoglobulin levels but not with complement components.

Adolescent↗
PubMed1984

Effect of histamine on the hippocampal neurons in guinea-pigs.

Histamine produced an excitatory effect on CA3 pyramidal cells in hippocampal slices of guinea-pigs. The amplitude of population spikes and EPSPs was augmented by histamine at concentrations of 10(-7) to 10(-6) M. Cimetidine but not pyrilamine prevented the stimulatory effect. The histamine effect was mimicked by dimaprit but not by 2-pyridylethylamine. It is concluded that histamine has a facilitatory influence on the hippocampal excitatory system via H2 receptor.

Animals↗
PubMed1984

Successful treatment of chromoblastomycosis with topical heat therapy.

Four female patients with chromoblastomycosis were completely cured by prolonged topical application of tolerable heat from pocket warmers. The lesions involuted after 2, 3, and 6 months, respectively, in three patients who faithfully followed our strict treatment schedule, in contrast to the fourth patient who performed the topical heat therapy in an irregular manner at home over a 12-month period. In vitro studies showed that the mature colonies of Fonsecaea pedrosoi, isolated from three of the patients, withstood persistent heating at 42.5 degrees C for more than 1 month. This suggested that heat killing of the causative organisms is unlikely to have been the sole reason for the effectiveness of this simple therapeutic modality.

Adult↗
PubMed1984

Activation of the alternative complement pathway by Fonsecaea pedrosoi.

Human sera were examined for evidence of complement activation by Fonsecaea pedrosoi. The serum that had been incubated with F. pedrosoi showed immunoelectrophoretic C3 conversion and generation of C5a, as measured by radioimmunoassay. C3 conversion and C5a generation did not occur in serum chelated with EDTA, or in serum heated to 56 degrees C for 30 min. Serum depleted of the heat (50 degrees C X 30 min)-labile factor B was also deficient in C3 conversion and C5a generation. Complement activation was not affected when the classical pathway was blocked by Mg++-EGTA. These studies indicate that F. pedrosoi can activate the complement system via the alternative pathway, with the resultant development of C5a.

Chromoblastomycosis↗
PubMed1984

HLA-DR antigen expression on the keratinocyte surface in dermatoses characterized by lymphocytic exocytosis (e.g. pityriasis rosea).

We have investigated the immunoperoxidase staining pattern of the epidermis in several dermatoses characterized by exocytosis of mononuclear cells into the epidermis. We found that HLA-DR antigens showed an intercellular distribution in localized areas of the epidermis in nine of ten cases of pityriasis rosea, and in all four cases of spontaneously regressing flat warts, two cases of pityriasis lichenoides chronica, two of Schamberg's disease, and one case of lichen striatus. Lichen planus and mycosis fungoides cases were used as positive controls. OKT6 antigen was recognized only on the dendritic cells of the epidermis in all these cases. Judging from the distribution of Langerhans cells, the epidermal intercellular HLA-DR antigen seems to be expressed on the keratinocytes in such diseases, and this feature was confirmed by immunoelectron microscopy. These findings support the hypothesis that the expression of HLA-DR antigen on keratinocytes in these dermatoses is linked to cellular immune reactions involving the epidermis.

Cell Membrane↗
PubMed1984

Dynamic changes in epidermal Ia-positive cells in allergic contact sensitivity reactions in mice.

In mice sensitized with trinitrochlorobenzene, serial changes in epidermal Ia-positive cells were studied at various times after challenge. Until 3 days post-challenge, the Ia-positive cells consisted only of dendritic Langerhans cells; their number was decreased but they were significantly enlarged, with extending dendrites. Some Langerhans cells were also found surrounding a hair follicle, extending their dendrites toward the follicle like the spokes of a wheel. From 3 to 9 days after challenge, keratinocytes also began to express Ia antigens in the epidermis in addition to Langerhans cells, whose size diminished. This suggests that there are two phases in the response of the epidermal Ia antigens in contact sensitivity reactions, i.e. an early phase in which enlarged Langerhans cells are the only Ia-positive cells in the epidermis, and a late phase in which keratinocytes take over as the major Ia-positive cells, while Langerhans cells resume their original size. Ia antigen expression on keratinocytes in this late phase probably plays a crucial role in completely eliminating allergens deposited on the keratinocytes.

Animals↗
PubMed1984

Mechanisms of pustule formation in cutaneous bacterial and viral infections: alterations of neutrophil membrane surface receptors.

Changes in membrane surface receptors have been demonstrated by rosetting methods in polymorphonuclear leukocytes obtained from the pustules of different infectious dermatoses. There was a distinct difference in numbers of receptors in neutrophils from bacterial and viral pustules, i.e., C3b receptors were decreased on neutrophils from both bacterial and viral pustules, whereas IgG-Fc receptors were decreased only in neutrophils from viral pustules. The difference appears to be due to variations in the defence mechanisms against the invading micro-organisms.

Acne Vulgaris↗
PubMed1984

Immunohistochemical staining characteristics of epidermal appendages (hair follicles and eccrine sweat glands) to anti-epidermal keratin antisera.

The cellular characteristics of the epidermal appendages and their differentiations in relation to those of the epidermis have been chiefly studied from the morphological points in the past. We investigated them from the immunohistochemical characteristics of the constituent keratin protein to the antiserum against total keratin isolated from human plantar stratum corneum (TKA) which stains the whole epidermis, and to the antiserum against 64K keratin separated from total keratin (64KA) which stains the whole epidermis except the basal layer. In the hair follicles, medulla and cortex of the hair shaft and inner root sheath were positively stained with both types of the antisera only at the keratogenous zone. The staining pattern of the outer root sheath with 64KA were variable at different levels of the hair follicle. The secretory portion of the eccrine glands showed a heterogeneous staining pattern as compared with the ductal portions which were stained homogeneously by both antisera. In eccrine poroma, all of the tumor cells were stained positively with TKA, while negatively or positively stained cells were intermingled with 64KA, suggesting that only some tumor cells showed mature keratinization.

Cell Differentiation↗
PubMed1984

Excitatory and inhibitory effects of H1-blockers on isolated bullfrog spinal cords.

Effects of pyrilamine and diphenhydramine on isolated spinal cords of bullfrogs were studied in order to clarify the mechanisms of depressant and stimulant actions of H1-blockers on the central nervous system. Pyrilamine and diphenhydramine depressed both the DR-VRP and DR-DRP. Pyrilamine and diphenhydramine also suppressed L-glutamate-induced depolarization of the motoneurones, but they did not depress GABA depolarization at the dorsal root terminals. By switching the perfusate to drug-free Ringer solution, depressed amplitudes of DR-VRP were suddenly increased over the control level (rebound phenomenon). The rebound increase of DR-VRP was inhibited by either tetrodotoxin or D-600. These results suggest that the rebound phenomenon may be due to the effect of H1-blockers 1) inhibiting transmitter release participating in presynaptic inhibition and 2) inducing a rapid recovery from the depressed influx of Na+ and Ca2+ into motoneurones.

Animals↗
PubMed1984

Activation of the alternative complement pathway by 405 nm light in serum from porphyric rat.

Sera from hexachlorobenzene-induced porphyric rats were examined for evidence of complement activation. The serum irradiated in vitro with 405 nm light resulted in a dose-dependent diminution of the total hemolytic activity of the complement. Further, such irradiated serum showed immunoelectrophoretical C3 conversion and chemotactic activity for rat polymorphonuclear leukocytes, and caused increased vascular permeability in vivo. C3 conversion was not induced in serum chelated with EDTA, but occurred in serum chelated with Mg++-EGTA. By sephadex G-75 chromatography, the irradiated serum had potent chemotactic activity eluted near the cytochrome C marker. These studies indicate that the irradiation of porphyric rat serum with 405 nm light induces activation of the complement system via the alternative pathway, with the resultant development of anaphylatoxin.

Animals↗
PubMed1984

Pustulosis vegetans.

Sterile pustules and crusted vegetative plaques on the trunk and limbs developed in a 24-year-old man. They left cribriform scars after healing. Histologically, the lesions showed epidermal proliferation and pustulosis resembling that found in "pyoderma vegetans" and pemphigus vegetans. The lesions were effectively suppressed in two months by the topical application of methoxsalen followed by UV-A irradiation. Studies revealed that the chemotactic activity of polymorphonuclear leukocytes (PMNs) in the patient's peripheral blood was enhanced and that an extract of lesional crusty scales showed the presence of a PMN chemotactic factor. This factor had a molecular weight near 12,500 daltons similar to that reported in psoriasis scales. We speculate that tissue destruction due to complement activation, possibly induced by immune complex-mediated reactions in the dermis, provoked a process of transepithelial elimination of the inflammatory products.

Adult↗
PubMed1984

Unilateral ashy dermatosis occurring in a child.

An unusual case of ashy dermatosis of Ramirez occurred in a 5-year-old-girl who had ash-colored hyperpigmented macules and plaques on the left leg and the left side of the trunk. These unilateral lesions showed histopathologic changes of a lichenoid tissue reaction. Although the exact cause of ashy dermatosis remains unknown, the positive test result for serum rheumatoid factor and the granular deposition of IgM at the dermoepidermal junction found in our case has immunologic implications.

Child, Preschool↗
PubMed1983

Profile of anti-stratum corneum autoantibodies in psoriatic patients.

Using autologous normal skin and freshly separated sera, the titers of circulating anti-stratum corneum (SC) IgG autoantibodies, which were predominantly demonstrated by ordinary indirect immuno-fluorescence (IF), and those of complement-fixing anti-SC autoantibodies were compared in 16 psoriatic patients with active lesions, 16 patients with nonpsoriatic inflammatory dermatoses, and 11 normal subjects. As in patients with other inflammatory dermatoses, the titers of IgG anti-SC autoantibodies in psoriatic patients were not specifically higher than in normal controls but were more variable, indicating that their circulating levels are dependent on a delicate balance between consumption at inflammatory sites and a secondary increase due to SC-antigen release following inflammation. The titers of complement-fixing anti-SC autoantibodies were much higher than those of IgG autoantibodies in most cases but they were not particularly high in psoriatic patients. From these findings, we think that if these autoantibodies are really involved in complement activation in inducing the transepidermal leukocyte migration of psoriatic lesions, a local factor of psoriatic epidermis, which may facilitate the permeation of these antibodies toward the SC, plays a more important role than the actual circulating antibody levels.

Adult↗