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Biomedical subjects

H Yokozeki

Publications and source records attributed to H Yokozeki.

At least 91 records · Page 5Linked to original sources
PubMed1995

Experimental study for the development of an in vitro test for contact allergens. 1. Primary activation of hapten-specific T cells by hapten-conjugated epidermal cells.

We conducted a study on the primary in vitro activation of T cells from non-sensitized mice by using hapten-conjugated Pam 212 cells (keratinocyte cell line). Furthermore, we attempted to develop a simple, quantitative in vitro test to assess the sensitizing potency of contact allergens and applied it to determine the stimulation index (SI) of various chemicals with known degrees of sensitizing potency. Monolayered Pam 212 cells were incubated with a variety of chemicals exhibiting allergenic potential. Washed and fixed T cells depleted of autoreactive T cells and macrophages from spleens of nonsensitized Balb/c mice were cocultured for 5 days with those monolayered Pam cells conjugated with chemicals. They were then harvested and restimulated with mitomycin-C-treated spleen cells conjugated with chemicals in 96-well culture plates to inhibit the proliferation of stimulator cells. We evaluated the sensitizing potency of the following chemicals: oxazolone, TNBS, DNFB and FITC (strong sensitizers); p-phenylendiamine (p-PD), nickel chloride and potassium dichromate (potent sensitizers); betamethasone and budesonide (corticosteroids), and methyl salicylate (MS) as an irritant. T cells sensitized in vitro with TNP-Pam cells and macrophages demonstrated antigen-specific proliferation when restimulated in vitro with mitomycin-C-treated TNP-spleen cells. Subcutaneous injection of these T cells induced contact sensitivity in vivo in an antigen-specific fashion. While T cells cocultured with TNP-3T3 could not be activated even in the presence of macrophages. The SI of strong sensitizers was about 4.00 and that of p-PD was 2.36. The SIs of budesonide, betamethasone and MS were 1.62, 0.98 and 1.21, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1994

Neoadjuvant intra-arterial doxorubicin chemotherapy in combination with low dose radiotherapy for the treatment of locally advanced transitional cell carcinoma of the bladder.

Between 1979 and 1990, 60 patients with locally advanced bladder cancer (stages T2 to 4NXM0) were treated with intra-arterial doxorubicin chemotherapy in combination with low dose radiotherapy and 36 (60%) achieved a complete remission. The tumor size (p < 0.01), tumor grade (p < 0.05) and clinical stage (p < 0.05) correlated significantly with the tumor response to the combined therapy. Of the 36 patients with complete remission and the 24 patients who did not achieve a complete remission 35 and 22, respectively, underwent a conservative bladder operation after treatment. Median followup was 71 months. The overall 5-year disease-free and cause-specific survival rates for the 60 patients were 49% and 72%, respectively. A significantly higher (p < 0.01) 5-year survival rate was observed in patients who achieved a complete remission (94%) than in those who did not (40%). The results suggest that intra-arterial chemotherapy plus radiotherapy is a useful regimen for patients with locally advanced bladder cancer, and bladder function may be preserved in those who achieve a complete remission.

Aged↗
PubMed1994

Oral minocycline improved keratosis follicularis squamosa (Dohi) and related disorder: bacterial factors are possibly involved in abberant keratinization.

Three cases of keratosis follicularis squamosa (Dohi) and one case of papillomatose confluente et reticulee were successfully treated with oral minocycline (50-100 mg/day). The clinical effect first appeared at 2 weeks after the initiation of therapy and no recurrence was observed for more than 3 months without minocycline. Gram positive cocci were demonstrated inside the hair follicle and horny layers in all 4 case. Minocycline might modulate abberant keratinization through its bactericidal effects in these keratinizing disorders.

Administration, Oral↗
PubMed1994

[Prognostic factors for muscle-invasive bladder cancer treated with a combination of intra-arterial chemotherapy and low-dose radiotherapy].

Clinical and pathological factors that affect short-term responses and long-term prognosis of muscle-invasive bladder cancer were studied in 73 patients who underwent a combination of intra-arterial chemotherapy and low-dose radiotherapy. Complete Response (CR) was observed in 41 (56%) of the 73 patients. The frequency of CR was significantly different according to the sex (males 64%, females 29%; p = 0.0239), clinical stage (T2 74%, T3 64%, T4 20%; p = 0.0005), tumor size (< 3 cm 81%. > or = 3 cm 31%; p < 0.0001), and tumor grade (G3 72%, G2 41%, p = 0.0127). By multivariate analysis, a significant difference was observed only in the tumor grade. The 5-year survival rate after bladder-preserving operations (median duration of follow-up 69 months) was significantly different according to the sex (males 75.2%, females 57.1%; p = 0.0427), clinical stage (T2 86.3%, T3 82.3%, T4 33.8%; T2 vs T4, p = 0.0005; T3 vs T4, p = 0.0107), tumor size (< 3 cm 89.6%, > or = 3 cm 47.2%; p = 0.0012), and tumor response (CR 95.0%, non-CR 38.6%; p < 0.0001). By multivariate analysis, a significant difference was observed only in the tumor response. The combination therapy of intra-arterial infusion and irradiation produced excellent short-term effects and prolonged the survival of the patients. Preservation of the bladder is considered to be possible in patients who obtained CR.

Aged↗
PubMed1993

Analysis of 70 KD heat shock protein (HSP70) expression in the lesional skin of lupus erythematosus (LE) and LE related diseases.

Biopsied specimens from skin lesions of SLE were studied for expression of 70 KD heat shock protein (HSP70). The pattern of HSP70 expression in SLE was diffuse in whole epidermis, hair follicles, and sweat gland cells and rather more intense than that in other control groups or normal skin. No significant differences in HSP70 expression were observed between sun-exposed and protected areas of SLE skin lesions. Unlike SLE, reduced or no expression of HSP70 was observed in skin lesions of DLE. In tissue culture, UVB radiation in vitro induced relatively intense expression of HSP70 in the nuclear area of keratinocytes. A few gamma delta T cell receptor positive cells which might respond to HSP70 expressing cells were detected in the basal layer of skin lesions of diseases. These studies suggest that aberrant expression of HSP70 in skin lesions of SLE might contribute to both skin lesions and antibody formation in SLE.

Adolescent↗
PubMed1993

Acral ichthyosiform mucinosis in association with Sjögren's syndrome: a peculiar form of pretibial myxedema?

Two Japanese women developed well-demarcated ichthyosiform plaques on the lateral aspect of their lower legs. Deposition of mucin was demonstrated throughout the papillary dermis, unlike the site of mucin deposition seen in pretibial myxedema. Their thyroid function was normal. The condition of both women was complicated by Sjögren's syndrome. One of them who presented with positive anti-microsomal and anti-thyroglobulin antibodies had goiter, suggesting that her malady was also complicated by Hashimoto's thyroiditis. Their skin manifestations differed from those described in cutaneous mucinosis including pretibial myxedema, specifically with regard to the well-demarcated ichthyosiform appearance, the mucin deposition in the papillary dermis, and the association with Sjögren's syndrome. To the best of our knowledge, our cases may thus be considered to be a previously undescribed form of cutaneous mucinosis associated with Sjögren's syndrome.

Adult↗
PubMed1993

A new variant of punctate acrokeratoderma associated with a pigmentary disorder.

We report a Japanese patient with skin-coloured keratotic papules on the hands and feet, and pronounced hyperkeratosis of the palms and soles. There was no evidence of fragmentation of dermal elastic tissue on histology. Freckle-like pigmentation was also present on the dorsa of the hands and feet, and this appeared to be closely related to the keratotic disorder. The mode of inheritance was autosomal dominant. We consider our case to be a new variant of familial punctate acrokeratoderma, associated with a pigmentary disorder.

Family↗
PubMed1993

Induction and characterization of mast cell colonies by culture supernatant of retinoic acid-treated mouse keratinocytes.

The retinoic acid-stimulated mouse-transformed epidermal cell line Pam 212 generated soluble mediators (RA-Pam sup) which showed mast cell-proliferating activity and induced mast cell-like colonies from bone marrow cells. Both mucosal-type and connective tissue-type mast cells were demonstrated on histochemical analysis. The 3T3 fibroblast cell line or human trichilemmomal cell line (TL1) also generated similar molecules on retinoic acid stimulation. Anti-stem cell factor antibody presented a rather more potent inhibitory activity on RA-Pam sup-dependent mast cell colony formation than did anti-IL3 and -IL4 antibodies. RA-Pam sup only induced mast cell colonies in semisolid culture and failed to promote mast cell growth in a suspension culture. In addition, mast cell colonies showed close contact with fibroblast-like cells on the methylcellulose plate, but this finding was not observed in culture without RA-Pam sup.

Animals↗
PubMed1993

Down-regulation of murine contact sensitivity by hapten-amino acid derivatives.

The low responsiveness of contact sensitivity (CS) in sensitized and challenged mice was induced by using hapten-amino acid derivatives. Subcutaneous injection of trinitrophenyl (TNP)-lysine or oxazolone-glycine inhibited ear swelling responses in mice that received rechallenge. The inhibitory effect was long-lasting and antigen-specific. TNP-lysine blocked the transfer of CS in vivo and the binding of immune lymph node cells to antigen in vitro. Thus, the suppression was mediated by inhibition of effector cells, but not associated with the generation of efferent limb-acting suppressor cells. The tool reported herein seems to be quite useful for controlling ongoing murine CS to simple chemicals.

Amino Acids↗
PubMed1993

Preparation and characterization of porous apatite ceramics coated with beta-tricalcium phosphate.

Hydroxyapatite (Ca10(PO4)6(OH)2; HA) is one of the most biocompatible materials with bones, and porous HA is promising bone substitute materials for clinical applications. While there are reports that beta-tricalcium phosphate (Ca3(PO4)2; TCP) has higher resorbability than HA when the material is implanted in a bone defect. In the present study, porous HA coated with beta-TCP was prepared by our unique method. The porous HA of about 60% porosity with interconnecting pore structure was soaked in diammonium hydrogen phosphate solution, and then the HA was sintered at 900 degrees C for 3 h. beta-TCP was revealed by X-ray diffractometry on the surface of porous HA. It was possible to control the content of surface-formed beta-TCP arbitrary by varying the concentration of the solution. The obtained HA coated with 33 wt% beta-TCP (33TCP) had about 60% open porosity with the pore size from 150 to 400 microns. The average compressive strength of this porous ceramics was 17.5 MPa. Surface coated HA with beta-TCP deprived of the brittleness in handling. The weight of HA implanted into muscles was increased obviously at 4 weeks because of formation of carbonate hydroxyapatite on the surface of HA. The weight of 33TCP was scarcely changed up to 12 weeks, but the weight tended to increase at 24 weeks. The carbonate hydroxyapatite was not formed on 33TCP at 4 weeks, but formed on it at 24 weeks. Therefore beta-TCP coated porous HA behaved like beta-TCP initially after implantation, and then behaved like HA.

Animals↗
PubMed1992

The role of metal allergy and local hyperhidrosis in the pathogenesis of pompholyx.

Pompholyx (Dyshidrosis) is a disease of unknown etiology presenting as symmetrical, vesicular hand and foot dermatitis. To clarify the pathogenetic role of sweat and metal allergy, twenty five patients with pompholyx were examined with respect to their perspiration volume using equipment that continuously recorded the local perspiration volume. Patients were also examined for metal allergy by patch testing and oral challenge tests. The perspiration volumes were measured using recently developed equipment for continuous recording of local perspiration volume (Kenz-Perspiro oss-100). The perspiration volume of pompholyx patients was found to be 2.5 times higher than that of age-matched normal controls. Twenty percent of the patients showed sensitivity to chromate, 16% to cobalt, and 28% to nickel on patch testing. Six patients with positive results were challenged orally in a controlled trial with 2.5 mg nickel, 1 mg cobalt, or 2.5 mg chromium. Four of them (67%) showed vesicular reactions on their hands with challenge testing. These results indicated a sensitivity to metal compounds which, in combination with local hyperhidrosis, may contribute to the development of vesicular lesions in pompholyx.

Adolescent↗
PubMed1992

Mast-cell-derived mediators induce epidermal cell proliferation: clue for lichenified skin lesion formation in atopic dermatitis.

Mast-cell-derived mediators showed mitogenic activities on mouse-transformed epidermal cell line Pam 212 cells. These activities were eluted into the low-molecular-weight fractions below a molecular weight of 10 kD on a high performance liquid chromatography TSK 2000G column, and were partially abrogated by antihistamines or anticytokine antibodies, including anti-IL1 alpha, -IL1 beta or IL6 antibodies. Pretreatment of mast cell lines with sodium butyrate enhanced the production of these factors. Calcium ionophore or Concanavalin A (ConA) stimulated mast cells to generate factor production. These results suggest that mast-cell-derived mediators might play some role in epidermal hyperplasia seen in lichenified lesions in atopic dermatitis.

Animals↗
PubMed1992

[A case of erythropoietin-producing renal cell carcinoma with a skin metastasis].

An 83-year-old man came to our hospital complaining of asymptomatic gross hematuria. We found a subcutaneous tumor in his chest and an abdominal mass in his left upper quadrant. Laboratory data showed red blood cell count of 737 x 10(4)/mm3 and hemoglobin level of 17.9 g/dl. The serum erythropoietin level measured by radioimmunoassay was considerably high. He underwent left nephrectomy and tumor resection in the chest wall. Serum erythropoietin level became normal following surgery and erythrocytosis disappeared. Histological findings revealed renal cell carcinoma, alveolar type, clear cell subtype, grade 2. The erythropoietin levels of the extracts of the cancer tissue and the normal kidney tissue were 2430 mU/g and 59.5 mU/g, respectively. Lung, liver and bone metastases appeared four months after the operation and serum erythropoietin level increased again.

Aged↗