A case of black-grain mycetoma occurring on the lower jaw with an odontogenic origin, which to our knowledge is the first case reported in China, is presented here. The clinical manifestation, histopathological morphology, and microbiological features are described. The new species, Madurella pseudomycetomatis, isolated from the black grains discharged by this patient, was analyzed using sequence data of the multiloci of ribosomal DNA (rDNA) and its ability to ferment carbohydrate as well as morphology. The analyses of the internal transcribed spacer (ITS) region and the D1/D2 hypervariable region of the 28S ribosomal gene sequences support a new species designation. Antifungal susceptibility testing was conducted, indicating that Madurella pseudomycetomatis was highly susceptible to itraconazole, voriconazole, and amphotericin B; moderately susceptible to terbinafine; and resistant to fluconazole and flucytosine.

Psoriasis is a chronic, inflammatory skin disease involving both environmental and genetic factors. According to genome-wide association studies (GWAS), the TNIP1 gene, which encodes the TNF-α–induced protein 3-interacting protein 1 (TNIP1), is strongly linked to the susceptibility of psoriasis. TNIP1 is a widely expressed ubiquitin sensor that binds to the ubiquitin-editing protein A20 and restricts TNF- and TLR-induced signals. In our study, TNIP1 expression decreased in specimens of epidermis affected by psoriasis. Based on previous studies suggesting a role for TNIP1 in modulating cancer cell growth, we investigated its role in keratinocyte proliferation, which is clearly abnormal in psoriasis. To mimic the downregulation or upregulation of TNIP1 in HaCaT cells and primary human keratinocytes (PHKs), we used a TNIP1 specific small interfering hairpin RNA (TNIP1 shRNA) lentiviral vector or a recombinant TNIP1 (rTNIP1) lentiviral vector, respectively. Blocking TNIP1 expression increased keratinocyte proliferation, while overexpression of TNIP1 decreased keratinocyte proliferation. Furthermore, we showed that TNIP1 signaling might involve extracellular signal-regulated kinase1/2 (Erk1/2) and CCAAT/enhancer-binding protein β (C/EBPβ) activity. Intradermal injection of TNIP1 shRNA in BALB/c mice led to exaggerated psoriatic conditions in imiquimod (IMQ)-induced psoriasis-like dermatitis. These findings indicate that TNIP1 has a protective role in psoriasis and therefore could be a promising therapeutic target.

To investigate the possibility of hair follicle reformation induced by dermal papilla cells in vivo and in vitro. Dermal papilla cells, dermal sheath cells obtained from human scalp skin by enzyme digestion were mixed with collagen to form mesenchymal cell-populated collagen gels. Superior and inferior epithelial cells and bulb matrical cells were then cultured on these gels by organotypic culture to recombine bilayer artificial skins. Dermal papilla cells and outer root sheath keratinocytes were mingled together and transplanted under subcutaneous tissue of the dorsal skin of nude mice. The results of histologic examination was observed with HE stain. These recombinants by organotypic culture all reformed bilayer structure like nature skin. Hair follicle-like structure reformation was found in dermal sheath cell-populated collagen gel when combined with superior or inferior epithelial cells. Dermal papilla cells also induced superior and inferior epithelial cells to form hair follicle on nude mice. Low passage dermal papilla cells mixed with hair follicle epithelial cells reformed many typical hair follicle structures and produced hair fibres after transplantation on nude mice. The dermal part of hair follicle, such as dermal papilla cells and dermal sheath cells, has the ability to induce hair follicle formation by interaction with the epithelial cells of hair follicle.

Histoplasmosis is a deep mycosis caused by Histoplasma capsulatum, which is endemic in many areas of the world but is relatively rare in China. Although the majority of cases present as a mild to moderate flu-like disease requiring only supportive therapy, approximately 1% of patients experience more serious pulmonary and extrapulmonary disease, which can be life-threatening if diagnosis is delayed or the treatment is not initiated rapidly. Definitive diagnosis is usually made by a combination of culture, detection of the organism in tissues, measurement of antibodies, and detection of antigen. We present the case of a 51-year-old patient who presented with histoplasmosis only, with several ulcerated lesions in the oral cavity and without HIV infection, who did not show any detectable signs and symptoms of systemic disease or extra-oral manifestations. Histopathological analysis indicated a chronic inflammatory process with granulomas with yeast-like organisms. Isolation of H. capsulatum and molecular identification provided the definitive diagnosis. Treatment with oral itraconazole led to remission of the oral lesions. This is the first Chinese case report of localized histoplasmosis with lesions restricted to the mouth in an HIV-negative patient.