Dermatophyte antigen kit: A useful diagnostic tool for onychomycosis.

A dermatophyte antigen kit (DQT) was released in Japan as an in vitro diagnostic tool to identify tinea unguium in June 2022. From July 2022 to February 2023, we examined 75 potassium hydroxide (KOH)-negative patients (male, n = 23; female, n = 52; mean ± SD age, 63.6 ± 13.9 years) and determined the accuracy in confirming the fungal element with ZoomBlue™ staining at 400× magnification. The DQT results were classified into three categories. DQT-positive onychomycosis was detected in 27 patients with tinea unguium and two with non-dermatophyte onychomycosis. Fungal cultures were positive in 14 (51.8%) patients (Trichophyton rubrum [n = 11], T. interdigitale [n = 1], Fusarium solani [n = 1], and Talaromyces muroii [n = 1]). DQT-negative onychomycosis included ten patients with cured tinea unguium and 3 with Candida onychomycosis. Twenty-three patients had DQT-negative mimics for onychomycosis (onychauxis [n = 11], traumatic onycholysis [n = 8], yellow nail syndrome [n = 5], pincer nail deformity [n = 3], brittle nail syndrome [n = 2], contact dermatitis [n = 2], lichen planus [n = 1] and psoriasis [n = 1]). Because sparse, atrophic and/or fragmented mycelia are invisible in direct microscopy with potassium hydroxide (KOH) at 100× magnification, DQT was beneficial for diagnosing onychomycosis.

Empiric antifungal therapy in patients with cutaneous and subcutaneous phaeohyphomycosis.

We encountered two cases of phaeohyphomycosis caused by Exophiala jeanselmei and E. oligosperma that were treated with fosravuconazole and terbinafine, respectively. Our cases were successfully treated with empiric therapy before the pathogen's species or antifungal sensitivity had been determined. We summarized 32 cases of cutaneous and subcutaneous phaeohyphomycosis caused by Exophiala species in Japan. The patients received antifungals, including itraconazole, terbinafine, voriconazole, and fosravuconazole, and the treatment success rates of these monotherapies were 77% (17/22), 67% (8/12), 100% (5/5), and 50% (1/2), respectively. Although the broad-spectrum azole antifungal itraconazole is the first choice for treatment, terbinafine at 125 mg/day might exert the same efficacy. Fosravuconazole is a novel broad-spectrum azole and a moderate inhibitor of Cyp3A4 that causes fewer drug interactions than itraconazole and voriconazole, indicating a promising drug for this disease.

Molecular basis of ubiquitin-specific protease 8 autoinhibition by the WW-like domain.

Ubiquitin-specific protease 8 (USP8) is a deubiquitinating enzyme involved in multiple membrane trafficking pathways. The enzyme activity is inhibited by binding to 14-3-3 proteins. Mutations in the 14-3-3-binding motif in USP8 are related to Cushing's disease. However, the molecular basis of USP8 activity regulation remains unclear. This study identified amino acids 645-684 of USP8 as an autoinhibitory region, which might interact with the catalytic USP domain, as per the results of pull-down and single-molecule FRET assays performed in this study. In silico modelling indicated that the region forms a WW-like domain structure, plugs the catalytic cleft, and narrows the entrance to the ubiquitin-binding pocket. Furthermore, 14-3-3 inhibited USP8 activity partly by enhancing the interaction between the WW-like and USP domains. These findings provide the molecular basis of USP8 autoinhibition via the WW-like domain. Moreover, they suggest that the release of autoinhibition may underlie Cushing's disease due to USP8 mutations.

Topical efinaconazole: A sequential combination therapy with oral terbinafine for refractory tinea unguium.

Efinaconazole is a topical antifungal drug approved in Japan for tinea unguium. Although topical treatments generally have low cure rates with a prolonged therapy period, a Cochrane review confirmed that high-quality evidence supports the effectiveness of efinaconazole for the complete cure of tinea unguium. Combination therapy is a way to improve the cure rate of onychomycosis. In this study, topical efinaconazole was administrated to 12 patients who had been treated with oral terbinafine (125 mg daily) for more than 20 weeks with little expected effect. Because terbinafine accumulates for a long time in the nail, treatment immediately followed by other drugs can be considered sequential combination therapy. During terbinafine monotherapy, the percentage involvement decreased from 53.5% to 44.0% after 37.4 weeks and the effective and cure rates were 16.7% and 0%, respectively. During sequential topical efinaconazole therapy combined with lasting terbinafine in the nail, the percentage involvement decreased from 44.0% to 18.7% after 28.4 weeks, and the effective and cure rates were 66.7% and 16.7%, respectively. The improvement rate per month of combination therapy (12.6%) was higher than that with monotherapy (2.1%) (p = 0.002). There were no serious side-effects. This sequential combination therapy with efinaconazole was effective in poor terbinafine responders, making it a promising regimen for improving the cure rate of tinea unguium.

Fosravuconazole to treat severe onychomycosis in the elderly.

Fosravuconazole is a novel oral antifungal drug developed in Japan and used to treat tinea unguium since 2018. Its excellent oral absorbability and systemic bioavailability has enabled short-duration therapy of 3 months. Furthermore, no concomitant drugs are contraindicated due to the presence of the mild inhibitor of cytochrome P450 enzyme which is responsible for polypharmacy adverse effects. Therefore, it can be safely administrated to elderly patients. Elderly patients (≥65 years old) with severe onychomycosis (≥50% nail involvement) were treated with oral fosravuconazole 100 mg once daily for 12 weeks. The rate of involvement improved from 86.6% to 28.1% (P < 0.01). The efficacy (i.e. percentage of those rated as "improved" and better) and cure rate was 83.8% (31/37) and 29.7% (11/37), respectively. Furthermore, when focusing on the thin nail group (<3 mm), the efficacy and cure rate was 88.2% (15/17) and 58.8% (10/17), respectively. Although the serum γ-glutamyltransferase levels increased in 21.6% (8/37), all patients recovered without any specific treatments.

Effects of the immunosuppressant rapamycin on the expression of human α2(I) collagen and matrix metalloproteinase 1 genes in scleroderma dermal fibroblasts.

BACKGROUND: Rapamycin has been shown to exert an anti-fibrotic effect on skin fibrosis in a certain subset of patients with systemic sclerosis (SSc) and in bleomycin-treated animal models. OBJECTIVES: To investigate the mechanism responsible for the anti-fibrotic effect of rapamycin especially by focusing on human α2(I) collagen (COL1A2) and matrix metalloproteinase 1 (MMP1) genes in normal and systemic sclerosis (SSc) dermal fibroblasts. METHODS: The expression levels of type I procollagen and MMP1 proteins were analyzed by immunoblotting and the mRNA levels of COL1A2 and MMP1 genes were evaluated by quantitative real-time RT-PCR. The activities of COL1A2 and MMP1 promoters were determined by reporter analysis. RESULTS: Rapamycin significantly decreased the levels of type I procollagen protein and COL1A2 mRNA, while significantly increasing the levels of MMP1 protein and mRNA in normal dermal fibroblasts. Similar effects of rapamycin were also observed in SSc dermal fibroblasts. Importantly, the inhibitory and stimulatory effects of rapamycin on the mRNA levels of COL1A2 and MMP1 genes, respectively, were significantly greater in SSc dermal fibroblasts than in normal dermal fibroblasts. In SSc dermal fibroblasts, rapamycin affected the expression of COL1A2 gene at the post-transcriptional level. In contrast, rapamycin altered the expression of MMP1 gene at the transcriptional level through the JNK/c-Jun signaling pathway in those cells. CONCLUSION: Rapamycin has a potential to directly regulate the deposition of type I collagen in extracellular matrix through inhibiting type I collagen synthesis and promoting its degradation by MMP1, suggesting that this drug is useful for the treatment of SSc.

Serum levels of soluble CD21 in patients with systemic sclerosis.

Systemic sclerosis (SSc) is a systemic disorder that typically results in fibrosis of the skin and multiple internal organ systems. Although the precise mechanism is unknown, overproduction of extracellular matrix proteins, including collagens and fibronectins, and aberrant immune activation might be involved in the pathogenesis. The soluble cluster of differentiation 21 (sCD21) represents the extracellular portion of the CD21 glycoprotein that is released by shedding from the cell surfaces into plasma. sCD21 binds complement fragments and activates monocytes through binding to membrane CD23. The present study was undertaken to investigate the serum levels of sCD21 in patients with SSc. Serum sCD21 levels were reduced with age both in patients with SSc and normal controls. Serum sCD21 levels in patients with SSc were significantly decreased compared to those in control subjects. When we divided patients with SSc into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), patients with lcSSc had lower levels of serum sCD21 than those with dcSSc. Moreover, the prevalence of pulmonary fibrosis in the patients with dcSSc inversely correlated with serum sCD21 levels. Our finding may support the notion that B-cell activation is involved in the mechanism for pulmonary fibrosis and skin sclerosis.

Beneficial effect of Sparassis crispa on stroke through activation of Akt/eNOS pathway in brain of SHRSP.

Sparassis crispa (S. crispa) is a mushroom used as a natural medicine that recently became cultivatable in Japan. In this study, we investigated not only the preventive effects of S. crispa against stroke and hypertension in stroke-prone spontaneously hypertensive rats (SHRSP) but also the mechanism involved by using studies of the cerebral cortex at a young age. Six-week-old male SHRSP were divided into 2 groups, a control group and an S. crispa group administered 1.5% S. crispa in feed, and we then observed their survival. In addition, rats of the same age were treated with 1.5% S. crispa for 4 weeks and we measured body weight, blood pressure, blood flow from the tail, NO(x) production, and the levels of expression of several proteins in the cerebral cortex by western blot analysis. Our results showed that the S. crispa group had a delayed incidence of stroke and death and significantly decreased blood pressure and increased blood flow after the administration. Moreover, the quantity of urinary excretion and the nitrate/nitrite concentration in cerebral tissue were higher than those of control SHRSP rats. In the cerebral cortex, phosphor-eNOS (Ser1177) and phosphor-Akt (Ser473) in S. crispa-treated SHRSP were increased compared with those of control SHRSP rats. In conclusion, S. crispa could ameliorate cerebrovascular endothelial dysfunction by promoting recovery of Akt-dependent eNOS phosphorylation and increasing NO production in the cerebral cortex. S. crispa may be useful for preventing stroke and hypertension.

Transcription factor Fli1 regulates collagen fibrillogenesis in mouse skin.

Biosynthesis of fibrillar collagen in the skin is precisely regulated to maintain proper tissue homeostasis; however, the molecular mechanisms involved in this process remain largely unknown. Transcription factor Fli1 has been shown to repress collagen synthesis in cultured dermal fibroblasts. This study investigated the role of Fli1 in regulation of collagen biosynthesis in mice skin in vivo using mice with the homozygous deletion of the C-terminal transcriptional activation (CTA) domain of the Fli1 gene (Fli1(DeltaCTA/DeltaCTA)). Skin analyses of the Fli1 mutant mice revealed a significant upregulation of fibrillar collagen genes at mRNA level, as well as increased collagen content as measured by acetic acid extraction and hydroxyproline assays. In addition, collagen fibrils contained ultrastructural abnormalities including immature thin fibrils and very thick irregularly shaped fibrils, which correlated with the reduced levels of decorin, fibromodulin, and lumican. Fibroblasts cultured from the skin of Fli1(DeltaCTA/DeltaCTA) mice maintained elevated synthesis of collagen mRNA and protein. Additional experiments in cultured fibroblasts have revealed that although Fli1 DeltaCTA retains the ability to bind to the collagen promoter in vitro and in vivo, it no longer functions as transcriptional repressor. Together, these results establish Fli1 as a key regulator of the collagen homeostasis in the skin in vivo.

Anti-p53 antibodies in patients with dermatomyositis/polymyositis.

Dermatomyositis/polymyositis (DM/PM), which is often accompanied by various immunological abnormalities, was reported to be associated with an increased incidence of malignancies. In this study, we analyzed serum levels of anti-p53 antibody (anti-p53 Ab) in DM/PM patients and in normal controls. Serum levels of anti-p53 Abs were significantly higher in DM/PM patients than those in healthy controls. However, there was no significant difference between serum levels in patients with malignancies and those in patients without malignancies. Anti-p53 Abs were positive in 13% (4 out of 31) of the DM/PM patients. Of these four patients, only one had an internal malignancy. Immunoglobulin G levels were significantly higher in patients positive for anti-p53 Ab than those who were not. These results seemed to suggest that the presence of anti-p53 Abs in DM/PM patients is due to immunological abnormalities in this disease.

Clinical features of scleroderma patients with contracture of phalanges.

Contracture of phalanges (CP) is a frequent complication of patients with systemic sclerosis (SSc). The objective of this study was to examine the prevalance of CP in patients with SSc and investigate the clinical and laboratory features of SSc patients with CP. Three hundred and fifty patients with SSc were examined. CP was found in 164 of the 350 patients (47%) with SSc. The prevalence of oesophageal involvement, pulmonary fibrosis or heart involvement was significantly greater in the patients with CP than that in those without CP. Our study suggested that the presence of CP may be a marker of oesophageal involvement, pulmonary fibrosis and heart involvement.