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H Tagami

Publications and source records attributed to H Tagami.

476 records · Page 27Linked to original sources
PubMedDate not supplied

Occurrence of neutrophils and activated Th1 cells in UVB-induced erythema.

We investigated the sequential changes in infiltrating inflammatory cells and several cytokine levels over a period of 48 h in human back skin exposed to 3 minimal erythematous doses of UVB. The measurement of blood flow, using a laser Doppler method, indicated that UVB-induced erythema reached a peak 12-24 h after irradiation. Immunohistochemically, an increase in the number of CD4+ T cells was observed in perivascular areas 6 h after the UVB treatment and continued for up to 48 h. CD8+ T cells were scarce until 24 h, but their numbers gradually increased thereafter. HLA-DR+ cells were detected perivascularly and interstitially in parallel with the pattern of CD4+ T-cell infiltration. In contrast, neutrophils were found 3 h after UVB exposure and reached a peak at 24 h. Using a RT-PCR method, we demonstrated that mRNAs for the Th1 cytokines (interferon-gamma and interleukin-2), together with a proinflammatory cytokine (interleukin-8), became detectable at 6 h, whereas mRNA for the Th2 cytokine (interleukin-4) was not found at all during the first 48 h. In contrast, we found an increase in mRNA levels for C3 and tumor necrosis factor-alpha even at 3 h, suggesting a relationship between complement activation and accumulating neutrophils. Our results suggest that neutrophils and CD4+ T cells in UVB-induced inflammation play different roles: neutrophils are more closely related to UVB-induced erythema, while T cells appear to be involved in subsequent dermal and epidermal inflammation accompanied by epidermal hyperproliferation.

Base Sequence↗
PubMedDate not supplied

Antigenicity of cryopreserved arterial allografts: comparison with fresh and glutaraldehyde treated grafts.

The use of cryopreserved aortic allografts in cardiovascular surgery is widespread and has resulted in excellent outcomes. However, it is controversial whether cryopreservation suppresses the antigenicity of tissue. We designed experimental models to study whether the cryopreservation process alters antigenicity in comparison with that found in fresh and glutaraldehyde treated tissues. Fresh, cryopreserved, and glutaraldehyde treated thoracic aorta from Brown Norway rats were subcutaneously implanted into Lewis rats. Inflammatory cells infiltrating around the grafts were measured on days 7, 14, 28, and 56 after implantation. The glutaraldehyde treated grafts showed significantly less infiltration than the fresh or cryopreserved grafts (p < 0.005). No significant difference was detected between the fresh and cryopreserved grafts. Another study examined the effect of modifications of the aortic allograft on subsequent allogeneic skin graft antigenicity. Subcutaneous implantation of fresh, cryopreserved, and glutaraldehyde treated aortic grafts from Brown Norway into Lewis rats resulted in subsequent skin graft rejection at 4.4+/-0.7, 5.1+/-0.8, and 6.6+/-2.1 days, respectively. There was no significant difference between the fresh and cryopreserved groups; whereas skin grafts in the glutaraldehyde group survived longer than those in the cryopreserved group. These results indicate that cryopreservation had no significant influence on antigenic suppression of arterial allografts.

Animals↗
PubMedDate not supplied

Pretreatment of a Dacron graft with tissue factor pathway inhibitor decreases thrombogenicity and neointimal thickness: a preliminary animal study.

The purpose of this study was to evaluate the effects of locally applied TFPI on the reduction of neointimal thickness in Dacron grafts. Seven millimeter internal diameter 5 cm lengths of albumin coated knitted Dacron grafts were interposed in the infrarenal aorta in 14 mongrel dogs. Before implantation, the grafts were immersed in saline solution containing 200 microg/ml of TFPI (TFPI group, n = 7) or 100 IU/ml of heparin (control group, n = 7) for 15 minutes at room temperature. Three months after implantation, neointimal thickness and percentage of graft stenosis were measured by computerized planimetry. All grafts were patent 3 months after implantation. Thrombus was found in one graft in the TFPI group, but observed in three of seven control grafts. Neointimal thickness in the TFPI group was significantly smaller than that in the control group (mean +/- SD, 0.26 +/- 0.1 mm vs. 0.57 +/- 0.15 mm, p < 0.001). Percentage of graft stenosis was significantly lower in the TFPI group than in the control group (13.4 +/- 5.3% vs. 26.9 +/- 7.0%, p < 0.001). Scanning electron micrographs showed that the neointima of TFPI treated grafts were completely covered by endothelial cells. The present results indicate that locally applied TFPI reduces thrombogenicity and neointimal thickness in albumin coated knitted Dacron grafts.

Animals↗
PubMedDate not supplied

Corynebacterium pyogenes. Its pathogenic mechanism in epidemic leg ulcers in Thailand.

There is a yearly outbreak of endemic leg ulcers in Thailand. Corynebacterium pyogenes, a pathogen to animals, is frequently isolated from the fresh lesions in addition to common pyogenic bacteria such as beta-hemolytic streptococci, mostly group A, and Staphylococcus aureus and Staphylococcus epidermidis. Although circulating titers of IgG and IgM anti-C. pyogenes antibodies were found to be very low in studied cases, intradermal skin test with C. pyogenes vaccine containing nonviable 10(5) microorganisms induced an erythematous reaction with maximum intensity at 6 hours; direct immunofluorescence showed granular deposition of C3 along the dermoepidermal junction at this time. Unexpectedly, the sites of such a skin test that subsequently underwent biopsy presented tender erythematosus induration 1 week later and developed granulomatous ulcerative lesions after 10 days in 11 of 15 patients. Radioimmunoassay for C5a and C5a of arginine demonstrated that C. pyogenes activated complement even in the absence of specific antibodies. These findings suggest that importance of skin injury followed by infection with C. pyogenes in the development of endemic leg ulcers, supporting our hypothesis that the infection of accidentally traumatized skin by C. pyogenes, which is carried by Oriental-eye flies, induces the granulomatous lesions of endemic leg ulcers.

Adolescent↗
PubMedDate not supplied

Decreased frequency of interferon-gamma-producing CD4+ cells in the peripheral blood of patients with atopic dermatitis.

Recently, decreased interferon-gamma (IFN-gamma) and increased interleukin (IL)-4 production have been reported in measurements of the content of the cytokines in culture supernatants of peripheral blood mononuclear cells (PBMC) obtained from patients with atopic dermatitis (AD). These data suggest deviation of PBMC into Th2-reactive cells in AD. In the present study, we examined the frequency of IL-2-, IL-4-, and IFN-gamma-producing cells in PBMC with flow cytometry. PBMC from 16 patients with AD and 18 healthy controls were stimulated for 2 days with anti-CD3 and IL-2, and further cultured for 4 days with a maintenance dose of IL-2. Thereafter these cells were restimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin for 4 h in the presence of monensin. After fixation of the cells, the cell membranes were made permeable and intracellular cytokines were stained with anti-IL-2, anti-IL-4 or anti-IFN-gamma antibody. Cytokine-producing cells were analyzed by gating CD4+- or CD8+-subsets. Thus counted frequency of IFN-gamma-producing cells was significantly decreased in CD4+ subsets of AD patients (9.9+/-7.4%) when compared with that in the controls (20.0+/-6.7%). There was no significant difference either in the frequency of IL-2- or IL-4-producing CD4+ subsets or in that of CD8+ subsets. Furthermore, in the enzyme-linked immunosorbent assay, we also found a decreased production of IFN-gamma in the culture of PBMC from AD patients, when compared with those from healthy controls, although it was only at a marginally significant level (P=0.07). Again there was no increase in IL-4 concentration in AD patients. In addition, we found a weak negative relationship between the disease severity and the frequency of these cells. These results suggest that the decreased frequency of IFN-gamma-producing CD4+ cells with subsequently decreased production of IFN-gamma play a crucial role in the pathophysiology of AD.

Adolescent↗
PubMedDate not supplied

Comparative study of the efficacy of various moisturizers on the skin of the ASR miniature swine.

The skin of the back of the ASR hairless miniature swine shows a rough and scaly fissured appearance. Clinically it resembles that of ichthyosis vulgaris or senile xerosis in humans. By using the skin of this animal, we developed an assay system to evaluate the efficacy of different moisturizers. The study was carried out in winter months from January to March. To establish this system, we studied various topical agents including such ordinary emollients as petrolatum and 10% salicylic acid in petrolatum as well as those available as pseudodrugs from cosmetic companies or prescription drugs from pharmaceutical companies such as heparinoid- containing creams (w/o and o/w) and 10% urea creams. Applying 0.01 g of each agent to 7 randomly selected skin areas (2x2 cm(2)) on the back of a 6-month-old swine once daily for various periods of time, we measured high-frequency conductance, the parameter for the hydration state of the skin surface. As a result, we have established a simple assay system. It consists of applications of topical agents once daily for 5 days from Monday to Friday in the first week and of subsequent measurement of the skin surface hydration state once every week. Evaluation measurements were performed from day 14 to day 21 depending upon their moisturizing effects. We found that heparinoid-containing creams exerted highly effective moisturizing effects on the dry pig skin that lasted even over 3 weeks after discontinuation of the treatments that were carried out for the first 5 days.

Animals↗
PubMedDate not supplied

A subepidermal blistering dermatosis associated with coexistent IgG and IgA anti-dermal basement membrane zone antibodies; demonstration of IgG antibodies reactive against a 200-kDa dermal antigen.

We report a 66-year-old woman presenting with an annular erythematous and bullous eruption. Her clinical and histological findings were similar to those of linear IgA bullous dermatosis or dermatitis herpetiformis. Direct immunofluorescence revealed linear deposition of IgA, IgG and C3 along the basement membrane zone (BMZ). Indirect immunofluorescence detected IgG and IgA antibodies against the BMZ. Salt-split skin technique demonstrated that IgG antibodies bound exclusively to the dermal side, while IgA antibodies bound not only to the dermal side, but also to the epidermal side with relatively weak intensity. On immunoblot analysis, the patient's IgG antibodies exclusively reacted with a band of 200-kDa, while the antigenic target of IgA antibodies was not identified. The present case is thought to be a unique bullous dermatosis mediated by both the IgG antibodies to a novel 200-kDa antigen and IgA antibodies against undetermined antigens.

Aged↗