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Biomedical subjects

I Katayama

Publications and source records attributed to I Katayama.

At least 73 records · Page 4Linked to original sources
PubMed1998

Comparative analysis of CD80 and CD86 on human Langerhans cells: expression and function.

Although both CD80 (B7-1) and CD86 (B7-2/B70) have been recently identified in cultured human Langerhans cells (LC), little is known of the role and regulatory properties of CD80 and CD86 on human LC. We present here the results of a study comparing the expression and function of CD80 and CD86 in human LC using the T-helper type-1 cytokines IL-2 and interferon gamma (IFN)-gamma, and the T-helper type-2 cytokines IL-10, IL-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF). Freshly isolated human LC expressed little CD80 and CD86 in vitro, but the expression of both molecules was rapidly induced during a 72-h incubation with cytokines and the expression of CD86 occurred much earlier and more strongly than that of CD80. The expression of both CD80 and CD86 was upregulated by GM-CSF and downregulated by IL-10, and the expression of CD86, but not that of CD80, was upregulated by both IL-4 and IFN-gamma. Finally, pretreatment of LC with GM-CSF and IFN-gamma, but not with IL-4, enhanced the alloreactive T-cell proliferation induced by the LC, and IL-10 pretreatment of LC decreased their capacity for alloreaction. These results indicate that the expression of both CD80 and CD86 on human LC may be regulated by these cytokines (IL-2, IL-4, GM-CSF, IFN-gamma and IL-10) secreted from helper T cells infiltrating into the inflammatory microenvironment.

Antigen Presentation↗
PubMed1998

The effects of estrogen deficiency on glycosylation of odontoblasts in rats.

To investigate the effects of estrogen deficiency on odontoblast metabolism, we induced osteoporosis in rats by ovariectomy and examined the glycosylation of the matrix component in odontoblasts. Peanut agglutinin (PNA) lectin histochemistry, which detects D-galactose and N-acetylgalactosamine sugars, was conducted in incisor odontoblasts of ovariectomized (OVX) and sham-operated (sham) rats. At 5 wk after the operation, bone mineral density and serum level of estrogen in OVX rats were lower than those in sham rats. PNA binding sites were found in the odontoblasts in incisors, and the binding sites in OVX rats were much stronger than those in sham rats. Furthermore, PNA binding sites were localized at the predentin matrix in OVX rats, but the reaction in sham rats was not detected. Because D-galactose and N-acetylgalactosamine sugars bound to PNA are important constituents of proteoglycans in dentin matrix and the PNA binding sites reflect the proteoglycan production of odontoblasts, these results indicated that galactosyl glycosylation of proteoglycans in odontoblasts is influenced by estrogen deficiency in rat incisors.

Acetylgalactosamine↗
PubMed1998

Repeated subcutaneous injection of staphylococcal enterotoxin B-stimulated lymphocytes retains epidermal thickness of psoriatic skin-graft onto severe combined immunodeficient mice.

Several approaches have recently been carried out to attempt to establish a mouse transplantation model of psoriasis. To study the effects of superantigen-driven peripheral blood mononuclear cells (PBMCs) on the persistence of psoriasiform epidermis and cytokine gene expression of the grafted psoriatic skin, staphylococcal enterotoxin B (SEB)-stimulated PBMCs (SEB-PBMCs) from psoriatic patients were subcutaneously injected once or repeatedly under the grafted full-thickness involved psoriatic skin onto severe combined immunodeficient (SCID) mice. After 5 weeks, the persistence of a psoriasiform epidermis was most distinct in mice with repeated injection of SEB-PBMCs. E-selectin expression was observed on endothelial cells in the upper dermis in mice with repeated injection of both SEB-stimulated and unstimulated PBMCs, while mice with single injection of unstimulated or SEB-PBMCs did not show positive staining. Both interleukin-1 beta (IL-1 beta) and interferon-gamma (IFN-gamma) mRNA were detected after 5 weeks, only in mice with repeated injection of SEB-PBMCs. It is concluded that continuous supply of the activated PBMCs may help the persistence of psoriasiform architecture more clearly, and that this transplantation mouse model may serve as an in vivo model for the study of the pathogenesis and therapy of psoriasis.

Adult↗
PubMed1998

RANTES expression in psoriatic skin, and regulation of RANTES and IL-8 production in cultured epidermal keratinocytes by active vitamin D3 (tacalcitol).

The chemokine RANTES is a chemoattractant for eosinophils, T lymphocytes of memory phenotype and monocytes, suggesting that it plays an important part in chronic inflammatory and allergic diseases. In various types of cells, RANTES production is markedly induced by tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma in combination. Psoriasis vulgaris is a chronic cutaneous inflammatory disease. Cytokines and chemokines produced by T cells and epidermal keratinocytes, such as interleukin (IL) 8, are involved in the pathogenesis of psoriasis. T-cell clones obtained from psoriatic skin have been shown to produce the Th1 cytokine IFN-gamma. In addition, abnormal expression of proinflammatory cytokines including TNF-alpha has been observed in psoriatic lesions. These reports led us to hypothesis that psoriatic skin could provide epidermal keratinocytes with TNF-alpha and IFN-gamma, so that keratinocytes could produce RANTES. In this study, we addressed the question as to whether RANTES was involved in psoriasis vulgaris. Immunohistochemistry of skin biopsies showed RANTES was present in the intercellular spaces between epidermal keratinocytes, in the fully developed lesions from the middle to the edge of psoriatic plaques, but not in the perilesional uninvolved and healthy control skin. Further, we confirmed the production of RANTES, together with IL-8, by cultured normal human epidermal keratinocytes, using an enzyme-linked immunosorbent assay. Stimulation with TNF-alpha and IFN-gamma in combination synergistically increased the RANTES production in this system. These results clearly demonstrate the expression of RANTES in psoriatic lesions and suggest the involvement of this chemokine in the outcome of cutaneous inflammatory diseases. Tacalcitol (1 alpha,24(R)-dihydroxyvitamin D3), an active vitamin D3 analogue, inhibited RANTES and IL-8 production in cultured normal epidermal keratinocytes. This result indicates that active vitamin D3 is effective in the regulation of chemokine production by epidermal keratinocytes, which may partly account for its action as an antipsoriatic drug.

Cell Culture Techniques↗
PubMed1998

Inducible nitric oxide synthase is expressed in granuloma pyogenicum.

It is known that granuloma pyogenicum (GP) grows rapidly but cherry angioma (CA) does not, although they show the same histological features of hyperplasia of the capillary vessels. Although some cytokines have been thought to be angiogenic factors, a nitric oxide (NO) synthase-dependent effector mechanism is reported to be involved in macrophage-derived angiogenesis in humans. Under the hypothesis that this mechanism is also involved in the more rapid growth of GP, we examined the expression of inducible NO synthase (iNOS) in GP as compared with that in CA. The expression of iNOS mRNA was detected in GP, but not in CA, by reverse transcription-polymerase chain reaction (RT-PCR) analysis. In situ hybridization (ISH) demonstrated iNOS mRNA expression in endothelial cells and to a lesser extent round cells and spindle cells in the myxomatous stroma in GP. Immunohistochemical study showed that iNOS protein was expressed in endothelial cells, infiltrating round cells and spindle cells in the stroma in GP. These results suggested that a NOS-dependent mechanism may be involved in angiogenesis and the rapid growth of GP.

Adult↗
PubMed1998

Possible involvement of interleukin-1 in the pathogenesis of dermatofibroma.

Dermatofibroma (DF) is histologically characterized by proliferation of fibroblasts in the dermis. Multiple DFs occasionally develop in patients with autoimmune disorders under immunosuppressive therapy; however, the pathogenesis of DF is still unclear. To elucidate immunological involvement in the mechanism of the fibrosis in DF, we studied the role of interleukin-1 (IL-1), which has a number of biological functions, including proliferation and collagen production of fibroblasts, on DF-derived fibroblasts. 3H-thymidine incorporation was used to examine the effects of Il-1 alpha and IL-1 beta in 4 cultured fibroblast strains derived from DF and 5 fibroblast strains from normal skin. Expression of mRNA of IL-1 was also analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). Basal 3H-TdR incorporation without stimulant of DF-derived fibroblasts showed a significantly greater growth activity than normal skin-derived fibroblasts (2, 632 +/- 525 vs. 762 +/- 144 dpm, p < 0.01). Both IL-1 alpha and IL-1 beta showed a stronger growth-stimulatory activity on DF-derived fibroblasts in a dose-dependent manner than normal fibroblasts, and the percent 3H-TdR uptake of DF was 1.4-fold (IL-1 alpha; 1,000 U/ml) and 1.3-fold (IL-1 beta; 1,000 U/ml) as compared with normal fibroblasts; however, the differences did not reach any significance. When increasing concentrations of IL-1 receptor antagonist (IL-1 alpha) were added to culture medium stimulated with IL-1 alpha, the proliferative response of fibroblasts was significantly reduced. Expression of IL-1 beta and RNA was detected on both DF-derived and normal skin-derived fibroblasts, while that of IL-1 alpha mRNA was detected only on DF-derived fibroblasts. Our results suggest that IL-1 may be involved in the fibrotic process in DF at the transcriptional level and play a role in the fibroblast proliferation in an autocrine manner.

Adult↗
PubMed1998

Restricted usage of the T-cell receptor V beta repertoire in tonsillitis in association with palmoplantar pustulosis.

Focal infections such as chronic tonsillitis or dental caries occasionally play a role in the induction or exacerbation of palmoplantar pustulosis (PPP). Arthro-osteitis is sometimes a complication in severe cases of PPP. To study the effects of bacterial infection on the exacerbation of cutaneous lesions and arthralgia, we investigated the T-cell receptor V beta repertoire in peripheral blood mononuclear cells (PBMC) and tonsil tissue after tonsillectomy in 4 cases, who had chronic tonsillitis and a history of exacerbation of cutaneous lesions following a sore throat. First, serum levels of interleukin-6 (IL-6) and IL-8 were measured before and after tonsillectomy by enzyme-linked immunosorbent assay (ELISA). Second, 3H-TdR incorporation was used to examine the effects of the culture supernatant on the PBMC of the autologous patients, other PPP patients without tonsillitis and normal controls. T-cell receptor V beta repertoire was examined by the reverse transcriptase-polymerase chain reaction method. Results showed that IL-8 was significantly high in the serum and abundantly released from tonsillar lymphocytes, which may play a role in the accumulation of neutrophils in lesional skin. T-cell receptors V beta 6 and 12 were preferentially expressed on tonsillar lymphocytes, and V beta 4, 7, 9, 17 and 18 were detected relatively frequently. These data suggest that restricted usage of T-cell receptor V beta subsets may play a crucial role in the induction of tonsillitis associated with PPP.

Adult↗
PubMed1998

Increased production of nitric oxide stimulated by interleukin-1beta in peripheral blood mononuclear cells in patients with systemic sclerosis.

OBJECTIVE: Nitric oxide (NO) is an important mediator of immune and inflammatory responses, and has recently been suggested to play some role in the pathogenesis of autoimmune disorders. In this study, we have examined whether peripheral blood mononuclear cells (PBMC) from patients with systemic sclerosis (SSc) produce higher levels of NO spontaneously or in response to several stimulations in vitro. METHODS: PBMC were obtained from 14 patients with SSc and 15 normal volunteers. Release of NO after stimulation with lipopolysaccharide (LPS), interleukin-lbeta (IL-1beta), tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) was determined by Griess reagents. RESULTS: PBMC from SSc patients exhibited a higher level of spontaneous release of NO (13.4+/-3.8 microM) than those from control subjects (8.9+/-1.6 microM), but without significance. Incubation of PBMC for 24 h with stimulants caused an increase in NO production both in normal subjects and SSc patients. Stimulation with 10 U/ml IL-1beta induced a significantly increased NO production in SSc patients (22.1+/-6.6 microM) compared with normal subjects (12.3+/-4. microM) (P < 0.05); however, in contrast, incubation with other stimulants showed no significant differences in NO production between SSc patients and normal subjects. CONCLUSION: These results suggest the abnormal regulation of NO production in PBMC of scleroderma patients in response to IL-1beta, which might contribute, in part, to the fibrotic process in SSc.

Adult↗
PubMed1998

Spongiotic annular erythema in SS-A/SS-B antibody negative Sjögren's syndrome.

We reported four cases of Sjögren's syndrome (SjS) who manifested a new type of annular erythema that differs from the previously described annular erythema seen in anti-SS-A/SS-B antibody positive SjS in both clinical and histological findings. Characteristic histological features are the presence of spongiotic changes around the acrosyringium and perivascular lymphocytic infiltration without liquefaction degeneration or epidermal change, suggesting lupus erythematosus. No complement or immunoglobulin depositions are demonstrated along the basement membrane zone or around blood vessels. Clinically, this type of erythema usually appears on the trunk or extremities with itchy sensations, especially in summer, which contrasts with the preferential occurrence of the previously reported SjS related annular erythema on the facial skin in winter. Immunologically, all four cases lacked anti-SS-A and anti-SS-B antibodies, but possessed positive anti-microsome antibodies or thyroid tests. In three cases, metal allergy was demonstrated by patch test, which might suggest that the sweat duct is the primary target of excreted metals in this condition and that underlying SjS might play some role in the higher prevalence of metal allergy or in induction of sweat duct injury, similar to the interstitial nephritis which is now thought to be an exocrine manifestation of SjS.

Adult↗
PubMed1998

A case of Post-kala-azar dermal leishmaniasis.

Only a few cases of Post-kala-azar dermal leishmaniasis have been reported in Japan, especially recently. We describe a case of a 32-year-old woman who developed rose-colored nodules on her forearms two years after Kala-azar. A skin biopsy specimen from a nodule revealed not only granulomatous changes but also many amastigotes of Leishmania donovani in macrophages. Rose-colored nodules were also distributed on her face and neck. Treatment with antimony compound was very effective.

Adult↗
PubMed1998

Topical anthralin therapy for refractory nail psoriasis.

The nail is commonly involved in psoriasis; however, very few therapies are satisfactory. In this study, we treated for 20 cases of psoriasis vulgaris with nail involvement with topical anthralin therapy. An ointment of 0.4-2.0% anthralin in petrolatum was applied to the affected nail bed once a day and washed away with water after 30 minutes. Then, 10% triethanolamine cream was applied to prevent undesired pigmentation. Within five months of therapy, twelve out of twenty psoriatic patients (60%) showed moderate and obvious improvement, four patients (20%) showed no response to this regimen. Onycholysis and pachyonychia both responded clinically, and the number of pitting was markedly decreased in some cases. The main side effect of anthralin therapy was reversible pigmentation of the nail plate. Topical anthralin therapy is effective for nail psoriasis and considered to be a useful treatment for refractory nail psoriasis.

Administration, Topical↗