Kang Zeng

Visual Detection of Hg2+ in Aqueous Solution Using Gold Nanoparticles and Thymine-Rich Hairpin DNA Probes

We report a sensitive method for visual detection of mercury ions (II) (Hg²⁺) in aqueous solution by using gold nanoparticles (Au-NPs) and thymine (T)-rich hairpin DNA probes. The thiolated hairpin DNA probe was immobilized on the Au-NP surface through a self-assembling method. Another thymine-rich, digoxin-labeled DNA probe was introduced to form DNA duplexes on the Au-NP surface with thymine-Hg²⁺-thymine (T-Hg²⁺-T) coordination in the presence of Hg²⁺. The Au-NPs associated with the formed duplexes were captured on the test zone of a lateral flow strip biocomponent (LFSB) by immunoreaction events between the digoxin on the duplexes and anti-digoxin antibodies on the LFSB. The accumulation of Au-NPs produced a characteristic red band on the test zone, enabling visual detection of Hg²⁺ without instrumentation. A detection limit of 0.1 nM was obtained under optimal experimental conditions. This method provides a simple, rapid, sensitive approach for the detection of Hg²⁺ and shows great promise for point-of-care and in-field detection of environmentally toxic mercury.

Visual Detection of Gene Mutations Based on Isothermal Strand-Displacement Polymerase Reaction and Lateral Flow Strip

Here, we describe a simple and sensitive approach for visual detection of gene mutations based on isothermal strand-displacement polymerase reactions (ISDPR) and lateral flow strip (LFS). The concept was first demonstrated by detecting the R156H-mutant gene of keratin 10 in Epidermolytic hyperkeratosis (EHK). In the presence of biotin-modified hairpin DNA and digoxin-modified primer, the R156H-mutant DNA triggered the ISDPR to produce numerous digoxin- and biotin-attached duplex DNA products. The product was detected on the LFS through dual immunoreactions (anti-digoxin antibody on the gold nanoparticle (Au-NP) and digoxin on the duplex, anti-biotin antibody on the LFS test zone and biotin on the duplex). The accumulation of Au-NPs produced the characteristic red band, enabling visual detection of the mutant gene without instrumentation. After systematic optimization of the ISDPR experimental conditions and the parameters of the assay, the current approach was capable of detecting as low as 1-fM R156H-mutant DNA within 75 min without instrumentation. Differentiation of R156H- and R156C-mutant DNA on the R156 mutation site was realized by using fluorescein- and biotin-modified hairpin probes in the ISDPR process. The approach thus provides a simple, sensitive, and low-cost tool for the detection of gene mutations.

Ultrastructural Study of Symmetrical Acral Keratoderma

Abstract Background: Symmetrical acral keratoderma is characterized by symmetrical brown hyperkeratotic patches on the acral extremities. However, no studies about its electron microscopic examination have been documented. Objective: Our study was performed to further characterize the histopathology of symmetrical acral keratoderma. Methods: A biopsy was taken from brown hyperkeratotic patches on the wrists. Investigative studies included light and electron microscopy. Results: Light microscopy showed epidermal basket-weave hyperkeratosis and acanthosis. Ultrastructurally, the epidermis was thickened by acanthosis and compact stratum corneum. The horny cell layers were remarkably thicker in clinical affected skin than in adjacent clinically unaffected and healthy skin. The keratin filaments were remarkably clumped or aggregated and irregularly distributed in the horny, spinous, granular and basal cell layers. The tonofilaments formed tight clumps or aggregated at the perinuclear cytoplasm. Conclusion: The main ultrastructural features of symmetrical acral keratoderma were epidermal hyperkeratosis and abnormalities of the keratin filaments and tonofilaments.

S159P mutation of keratin 10 gene causes severe form of epidermolytic hyperkeratosis

highlights MEC as a common finding in DA. Although mechanisms underlying formation of MEC in non-viral conditions are poorly understood, cell-cell fusion and disruption of cytokinesis are possible explanations. While viral infections must be excluded, our experience suggests the presence of MEC with greater than five nuclei, when accompanied by epidermal necrosis and in the appropriate clinical setting, may provide a clue to the diagnosis of DA in the paediatric population. J. Guitart had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: J. Guitart. Acquisition of data: S. Amin, O. Y elamos, M. Martinez-Escala, L. Shen., J. Guitart, M. Rosenbaum, B. Kenner-Bell, A. Mancini, A. Paller. Drafting of the manuscript: S. Amin, O. Y elamos, M. Martinez-Escala, J. Guitart. Critical revision of the manuscript for importance intellectual content: J. Guitart, B. Kenner-Bell, A. Mancini, A. Paller, M. Rosenbaum, P. Gerami. Administrative, technical or material support: J. Guitart, S. Amin, O. Y elamos, M. Martinez-Escala. Study supervision: J. Guitart.

Exome sequencing identifies a TCF4 mutation in a Chinese pedigree with symmetrical acral keratoderma

Symmetrical acral keratoderma (SAK) is a rare skin disorder and its pathogenesis and inheritability are unknown.

Efficacy and safety of acitretin monotherapy in children with pustular psoriasis: results from 15 cases and a literature review.

Abstract Background: There is a few evidence-based information regarding the efficacy and safety of acitretin treatment in children with pustular psoriasis (PP). Objective: This study aimed to provide an additional evidence for this field. Methods: A retrospective study was undertaken for 15 children with PP who received acitretin in doses of 0.6–1.0 mg/kg/day for 4–6 weeks, the transition dose of 0.2–0.4 mg/kg/day for 4–6 weeks and maintenance dose of 0.2–0.3 mg/kg/day. Additionally, a literature review on this topic is conducted. Results: Of 15 children with generalized PP (GPP, n = 10), palmoplantar psoriasis (PPP, n = 3), and acrodermatitis continua of Hallopeau (ACH, n = 2), 93.3% (14/15) showed good response, only one case with ACH exhibited moderate response. During the 10–32 months of follow-up, acitrerin monotherapy for children cases with PP overall showed good efficacy and safety. In the literature review, a total of 107 childhood PP cases treated with acitretin in 21 studies were included in the analysis. The clinical effectiveness was obtained in 88.8% (95/107) patients treated with acitretin as monotherapy or combination therapy, and most of cases (92.6%, 100/107) treated by acitretin did not report side effects during the treatment and follow-up of acitretin. Limitation: This study is just included a small sample sizes and no standardized studies were used in the literature. Conclusion: Acitretin therapy for children with PP (monotherapy or combination therapy), all showed a satisfactory therapeutic effect and safety, independent of the short or long-tern therapeutic procedures.