Porokeratosis: clinical analysis of seven cases / 中华全科医师杂志

The clinical data of 7 patients with porokeratosis (PK) were analyzed retrospectively.In 7 PK patients, 4 cases were disseminated superficial actinic porokeratosis (DSAP),1 case was disseminated superficial porokeratosis (DSP),1 case was giant porokeratosis (GP) and 1 case was hypertrophic porokeratosis (HP).The characteristic cutaneous manifestations were annular well-circumscribed keratotic plaques with slightly atrophic center and elevated border.All patients shared a common histological hallmark, the cornoid lamella.Four cases of DSAP patients had family medical history, consistent with autosomal dominant inheritance.DSP, GP and HP patients denied family medical history.Diagnosis of PK should be based on clinical manifestations, family medical history and histopathological examination.

Photoprotective effect of the N-terminal 5-mer peptide analog P165 of amyloid precursor protein in human dermal fibroblasts / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>We showed in our previous study that the N-terminal 17-mer peptide of amyloid precursor protein (APP17-mer peptide), an active peptide segment with trophic and antioxidative effects, protects skin fibroblasts against ultraviolet (UV) damage and downregulates matrix metalloproteinase 1 (MMP-1) expression. The aim of the current study was to explore the protective effects of P165, the N-terminal 5-mer peptide analog of amyloid precursor protein that is resistant to enzymolysis, on UVA-induced damage in human dermal fibroblasts (HDFs).</p><p><b>METHODS</b>HDFs were cultured in Dulbecco's modified Eagle's medium without and with P165 (concentrations were 1, 10, and 100 µmol/L). Then, 15 J/cm(2) UVA irradiation was used to obtain the UV-irradiated model. Cell proliferation was analyzed using MTT kit. The collagen type I and MMP-1 contents in cell lysate were determined by enzyme-linked immunosorbent assay (ELISA). Fluorometric assays were performed to detect the formation of intracellular reactive oxygen species (ROS) in the cells.</p><p><b>RESULTS</b>P165 significantly protected the HDFs against UVA-induced cytotoxicity. Compared with the UVA-irradiated control, 1, 10, and 100 µmol/L P165 elevated cell proliferation by 14.98% (P < 0.05), 17.52% (P < 0.01) and 28.34% (P < 0.001), respectively. Simultaneously, 10 and 100 µmol/L P165 increased collagen type I content (both P < 0.05). Moreover, P165 treatment (all concentrations) also markedly suppressed the UVA-induced MMP-1 expression (all P < 0.001). P165 at 1, 10, and 100 µmol/L also reduced UVA-induced ROS generation by 11.27%, 13.69% (both P < 0.05), and 25.48% (P < 0.001), respectively.</p><p><b>CONCLUSIONS</b>P165 could protect the HDFs against UVA-induced photodamage, including cytotoxicity, and MMP-1 generation. Furthermore, it also increased the collagen type I content in the cells. The inhibitory effect on intracellular ROS generation might be involved in these photoprotective effects. Thus, P165 may be a useful candidate in the prevention and treatment of skin photoaging.</p>