Ryoji Tsuboi's research while affiliated with Tokyo Medical University and other places

Publications (326)

Chapter
The dermal sheath (DS) cells are present in a sheath-like connective tissue on the outermost side of the hair follicle; DS connects to the dermal papilla (DP) in the lower part of the hair bulb. The ability of DP cells to induce and regenerate hair follicles has been demonstrated in a great number of studies as discussed in other chapters. In this...
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Background/aim: MST-16 and VP-16, both of which are topoisomerase II inhibitors, are antitumor agents regularly used to treat malignant lymphoma and small cell lung carcinoma. New therapeutic agents for tumor stage mycosis fungoides (MF) have recently been developed, but their efficacy is limited. We herein retrospectively reported the use of MST-...
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Onychomycosis with longitudinal spikes in the nail plate has been reported to be refractory to oral drugs as with dermatophytoma. We evaluated the efficacy of 10% efinaconazole solution in the treatment of onychomycosis with longitudinal spikes. Of the 223 subjects who were enrolled in a previous study, a post-hoc analysis of 82 subjects with longi...
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Tinea unguium is a common nail disease caused by dermatophytes. Although direct potassium hydroxide (KOH) microscopy and fungal culture are considered the gold standard for diagnosing this disease, their accuracy is insufficient. A lateral flow immunochromatographic assay (LFIA) kit, using a monoclonal antibody against Trichophyton rubrum, was deve...
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Intra‐anal warts are frequently recalcitrant to surgical removal, but imiquimod 5% cream is not formulated to use in clinical practice due to the risk of mucosal inflammation. In the present, prospective, open study examining the efficacy and safety of imiquimod 5% cream, the drug was applied to the entire inner surface of the anal canal with a cot...
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The present, retrospective, single‐center study analyzed various factors associated with primary basal cell carcinoma (BCC) in the period before and after the introduction of dermoscopy (BD and AD, respectively). The demographic data of patients with primary BCC between 2001 and 2005 (BD: 84 patients, 90 cases) and 2011 and 2018 (AD: 297 patients,...
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The "Guidelines for the management of dermatomycosis" of the Japanese Dermatological Association were first published in Japanese in 2009 and the Guidelines Committee of the Japanese Dermatological Association revised it in 2019. The first guidelines was prepared according to the opinions of the Guidelines Committee members and it was of educationa...
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We compared the incidence of various ocular comorbidities and the clinical severity of AD using the Eczema Area and Severity Index (EASI) score.
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Background Folliculitis decalvans (FD) is a form of inflamed primary cicatricial alopecia (PCA). FD is classified as a neutrophilic PCA; however, only a few previous studies have described its histopathology, including the assessment of systematically evaluated and quantified follicular changes in horizontally sectioned biopsy specimens with clinic...
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Background Few effective treatments are available for male pattern hair loss (MPHL) and especially for female pattern hair loss (FPHL). Recently, cell-based therapies using autologous or allogeneic cells have been used clinically. Objective We examined the safety and efficacy of autologous cell–based therapy using dermal sheath cup (DSC) cells to...
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Seborrheic dermatitis (SD) is a multifactorial disease in which Malassezia restricta has been proposed as the predominant pathogenic factor. However, experimental evidence supporting this hypothesis is limited. A guinea pig SD model using a clinical isolate of M. restricta was used to elucidate the pathogenicity of M. restricta. Also, the efficacy...
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In vitro antifungal activity of luliconazole against nondermatophytic moulds causing superficial infections was compared with that of five classes of 12 topical and systemic drugs. The minimum inhibitory concentration (MIC) of the drugs against the genera of Neoscytalidium, Fusarium, Aspergillus, Scedosporium, and Alternaria was measured via modifi...
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Background: Lysophosphatidic acid (LPA), generated by autotaxin (ATX), is a bioactive lipid mediator that binds to the receptors (LPA1-6), and serves as an important mediator in inflammation. Previous studies have demonstrated that LPA-LPA1 cascade contributes to arthritis and skin sclerosis. In this study, we examined the role of LPA signals in m...
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Purpose To elucidate the recent trends in prevalence and characteristics of ocular complications of atopic dermatitis (AD). Study Design Cross-sectional observational study. Methods Among AD patients who visited our department between 2012 and 2015, 70 patients (140 eyes; recent AD group) who gave informed consent to participate in the study were...
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We evaluated the efficacy of efinaconazole 10% topical solution in long‐term use, for up to 72 weeks, for onychomycosis, including severe cases. Among 605 participants, 219 patients diagnosed as having onychomycosis were evaluated for the efficacy of efinaconazole. The treatment success rate (<10% clinical involvement of the target toenail) at the...
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The present study (B‐1201 clinical trial) was conducted as a multicenter, open‐label, single‐arm phase II study to evaluate the long‐term safety, tolerability and efficacy of bexarotene. This study enrolled 10 Japanese adults aged more than 20 years with cutaneous T‐cell lymphoma (CTCL) who completed the 24‐week study period of the B‐1101 trial. Th...
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Objective: There are few epidemiological reports of anaphylaxis since childhood. We herein examined cases of anaphylaxis diagnosed in our department. Methods: One hundred-thirty-two patients who were examined at the Dermatology Department of Tokyo Medical University Hospital between January 2011 and March 2017 and were prescribed epinephrine aut...
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Pustulotic arthro‐osteitis, occasionally complicated with palmoplantar pustulosis, affects patients’ activities of daily living. Granulocyte and monocyte adsorption apheresis selectively removes activated granulocytes and monocytes by means of extracorporeal circulation. Although the efficacy of granulocyte and monocyte adsorption apheresis in the...
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Background We experienced a rare case of immediate type hypersensitivity and late phase reaction to anti-tubercular therapy consisting of ethambutol and levofloxacin, which occurred in close succession, giving the appearance of a single, continuous reaction to one drug. Case presentation The patient was a man in his 70’s who began therapy consisti...
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Lichen planopilaris (LPP) is a primary cicatricial alopecia characterized by the infiltration of lymphocytes in the upper portion of hair follicles. Inflammation around the bulge region of hair follicles induces destruction of hair follicle stem cells and tissue fibrosis, resulting in permanent hair loss. Treatment is still challenging, and the pre...
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Levels of IL36α are known to be increased in specimens from patients with atopic dermatitis and psoriasis. In addition, it has been reported that IL-36α is crucial for development of imiquimod-induced psoriatic dermatitis in mice. On the other hand, the role of IL-36α in induction of allergic contact dermatitis/contact hypersensitivity (ACD/CHS) is...
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A milky lotion containing camellia oil was administered to 46 patients with drying dermatoses including atopic dermatitis, asteatotic eczema, xeroderma, and senile pruritus for 4 weeks to examine its safety. The subjects were patients who regularly visited the Department of Dermatology at Tokyo Medical University Hospital, Ageo Central General Hosp...
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Male‐pattern hair loss (MPHL, androgenetic alopecia) is a slowly progressive form of alopecia which begins after puberty. In 2010, we published the first Japanese edition of guidelines for the diagnosis and treatment of MPHL. It achieved the original goal of providing physicians and patients in Japan with evidence‐based information for choosing eff...
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Inflammasomes are multimolecular complexes that control the inflammatory response. The function of inflammasomes in the pathogenesis of psoriasis is still unclear. To clarify the relationship between inflammasomes and the pathophysiology of psoriasis, and in particular, to identify molecules interacting with caspase‐1, a crucial component of inflam...
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Bathing and cleansing of the body are essential to maintaining good hygiene, but when done in excess, can promote dry skin among the elderly. In order to assess the appropriate conditions for bathing and body cleansing for the elderly, we conducted a survey of bathing practices at 105 hospital wards. The results demonstrated that in most wards surv...
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An 86-year-old woman noted a subcutaneous mass in the left axilla 2 months before presentation. A biopsy of an enlarged axillary lymph node showed proliferation of CK20-positive basophilic small tumor cells. Computed tomography of the chest and abdomen detected multiple lymph nodes in the left axilla alone ; other than in the left axilla, no lesion...
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The Structure, Biology & Hair Curl, Colour, and Luster Session included two invited presentations and three selected from submitted abstracts. These presentations taken together highlight current progress in linking follicle biology to the tensile/physical properties of hair. They show progress in understanding the development of the hair fiber, an...
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The etiology of purpura in Sjögren syndrome (SS) includes cryoglobulinemia, hypergammaglobulinemia, and leukocytoclastic vasculitis (LCV). The clinical symptoms of LCV associated with SS comprise palpable or nonpalpable purpura and urticarial vasculitis. Here, we report a case of LCV presenting as erythema gyratum repens (EGR)-like purpura in a 62-...
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Objectives Sphingosine 1-phosphate (S1P) is a bioactive lipid that binds to cell surface receptors (S1P1–5). In this study, we examined the effect of S1P1 agonist, ONO-W061, on murine Candida albicans water-soluble fraction (CAWS)-induced vasculitis. Methods Mice were administered ONO-W061, and the number of peripheral blood cells was counted. Vasc...
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Background: Immune checkpoint inhibitors and kinase inhibitors have improved prognosis of malignant melanoma (MM) patients. However these therapies cannot completely overcome the metastasis of MM. Thus development of new therapy against metastasis should be required. A first step towards this goal, the aim of this study, is to establish a model of...
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The present study was conducted to retrospectively evaluate survival and local control with definitive brachytherapy in patients with cutaneous angiosarcoma of the scalp and/or face, and to determine the optimal radiation dose and irradiated volume. Between November, 2009 and January, 2015, 9 consecutive patients with histologically proven angiosar...
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Affinity of Luliconazole (LLCZ), an antifungal drug used for topical treatment of onychomycosis in Japan, to nail keratin was demonstrated. Efinaconazole (EFCZ) was used as a reference drug. Drugs at fixed concentrations were added to 4 ml of buffer solution containing 40 mg of nail keratin powder prepared from healthy volunteers or from tinea ungu...
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Bacterial colonization on skin or tonsil may influence the clinical response of patients with psoriasis to immunosuppressive drugs. However, few studies have investigated the effects of bacterial superantigens on therapy in these patients. Recently, combination therapy with topical glucocorticoids (GC) and vitamin D3 (VD3) appears to be more effect...
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Safety, tolerability, pharmacokinetics and efficacy of bexarotene, a novel retinoid X receptor (RXR)-selective retinoid, were evaluated in Japanese patients with stage IIB–IVB and relapsed/refractory stage IB–IIA cutaneous T-cell lymphomas (CTCL). This study was conducted as a multicenter, open-label, historically controlled, single-arm phase I/II...
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We previously reported a positive feedback loop between S100A8/A9 and pro-inflammatory cytokines mediated by extracellular matrix metalloproteinase inducer (EMMPRIN), an S100A9 receptor. Here, we identify neuroplastin-β (NPTNβ) as an unreported S100A8 receptor. NPTNβ and EMMPRIN form homodimers and a heterodimer, and are co-localized on the surface...
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Seborrheic dermatitis (SD) is a chronic inflammatory dermatologic condition, in which erythema and itching develop on areas of the body with sebaceous glands, such as the scalp, face, and chest. The inflammation is evoked directly by oleic acid, which is hydrolyzed from sebum by lipases secreted by skin microorganisms. Although the skin fungal genu...
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Infection by Trichophyton tonsurans is an emerging fungal epidemic in Japan. Itraconazole (ITZ) and terbinafine have been used for the treatment of this infection for 15 years. However, patients with T. tonsurans infections have been shown to remain uncured or to become reinfected, suggesting that subclinical infection or polyphyletic strains and/o...
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Luliconazole (LLCZ), an imidazole derivative with a broad spectrum of potent antifungal activity especially for T. rubrum and T. mentagrophytes, is under development as a new drug for treatment of tinea unguium. It is well known that curative effect of an antifungal agent in dermatophytosis is affected by the pharmacokinetics of an agent at the inf...
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Bleomycin-induced scleroderma in mice is an established model for human scleroderma. Making use of this, we have established a new model for wound retardation. After inducing dermal sclerosis by local bleomycin treatment in nude mice, a full-thickness wound was made by punch excision on the bleomycin application site. Mice pretreated with bleomycin...
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The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of luliconazole against Trichophyton rubrum (14 strains) and Trichophyton mentagrophytes (14 strains), which are the most common cause of tinea, were compared with those of 6 topical antifungal drugs of lanoconazole, bifonazole, efinaconazole, liranaftate, naf...
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Androgenetic alopecia is an androgen-induced pattern of progressive hair loss, which occurs in genetically predisposed people. This study aimed to determine long-term safety, tolerability and efficacy of dutasteride 0.5 mg, an inhibitor of 5-α-reductase, in Japanese male patients with androgenetic alopecia. This was a multicenter, open-label, prosp...
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Intravascular large B-cell lymphoma (IVL) is a rare subtype of extranodal malignant lymphoma. The proliferation of neoplastic B cells within small blood vessels causes eruptions and other symptoms in a variety of organs. The random skin biopsy is useful for diagnosing this condition in its early stages. In order to assess the diagnostic utility of...
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Objective: To compare drug concentrations in the stratum corneum following daily application of luliconazole and terbinafine cream in a guinea pig tinea pedis model. METHODS: Luliconazole 1% cream or terbinafine 1% cream were topically applied once daily to hind limbs of guinea pigs for 14 days. Drug concentration in stratum corneum of plantar ski...
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We herein report a case of hair follicle nevus, a rare hamartoma found on the face and showing follicular differentiation, which was associated with sebaceous hyperplasia. Dermoscopy of the lesion showed yellow globules surrounded by crown vessels/telangiectasias and scattered tiny hairs. Histopathological investigation revealed hyperplasia of the...
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Background: IL-33, a member of the IL-1 cytokine family, binds to heterodimeric receptors ST2 and IL-1 receptor accessory protein, and activates Th2-type immune responses. The signals from the ST2 receptor are mediated by the two major pathways, including AP-1 and NF-κB molecules. The present study examined whether IL-33 induced ICAM-1 expression...
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Background: Retinoids exert anti-proliferative, differentiative, and apoptosis-inducing effects through their receptors. Retinoic acid receptor (RAR) β2 behaves as a tumor suppressor gene, and its expression is suppressible by DNA methylation in many malignancies. Objective: We aimed to determine whether combining a retinoid, Am 80, with a histo...
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Erythema dyschromicum perstans (EDP) and ashy dermatosis (AD) are pigmentary disorders of unknown etiology. EDP is usually considered to be identical to AD; however, a new clinical classification for EDP was proposed in the recent literature. Herein, we report a typical case of EDP observed in an African-American man. Interestingly, the late skin l...
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Regarding appropriate timings of discontinuation and resumption of biologics for psoriasis patients before and after elective surgeries, an international consensus has yet to be reached. The Japanese Dermatological Association of Guideline and Safety Manual for the use of Biologic Agents in Psoriasis 2013 states that infliximab (IFX) and adalimumab...
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Vitamin D3 ointment and corticosteroid ointment are both used for the treatment of palmoplantar pustulosis (PPP). However, to date there is no systematic study of the efficacy of combination therapy for the treatment of PPP. We compared the efficacy of a topical combination therapy with vitamin D3 and a topical corticosteroid with that of topical c...