Enantiomeric Separation and Determination of the Enantiomeric Impurity of Armodafinil by Capillary Electrophoresis with Sulfobutyl Ether-β-cyclodextrin as Chiral Selector

A selective capillary electrophoresis method using sulfobutyl ether-β-cyclodextrin as a chiral selector was developed and validated for the determination of the enantiomeric impurity of (R)-modafinil, i.e., armodafinil. Several parameters were optimized for a satisfactory enantioresolution, including the type and concentration of chiral selector and organic modifier, pH of background electrolyte (BGE), capillary temperature. The finally adopted condition was: 20 mmol/L phosphate buffer at pH 7.5, containing 20 mmol/L sulfobutyl ether-β-cyclodextrin and 20% methanol, at temperature of 25 °C. A good resolution of 3.3 for the two enantiomers of modafinil was achieved by applying the optimal conditions. The limit of detection (LOD) and limit of quantification (LOQ) of (S)-modafinil were 1.25 μg/mL and 2.50 μg/mL, respectively. The established method was also proven to display good selectivity, repeatability, linearity and accuracy. Finally, the method was used to investigate the enantiomeric purity of armodafinil in bulk samples

Seven cases of dermatitis caused by benzalkonium chloride disinfectant

Objective To analyze the clinical manifestations and histopathological features of 7 cases of dermatitis caused by benzalkonium chloride disinfectant, so as to enhance the understanding of this disease. Methods We retrospectively analyzed the clinical manifestations and pathological features of benzalkonium disinfectant-induced contact dermatitis in 7 cases who visited our clinic from August to November 2022. Results The clinical manifestations were repeated annular erythema and desquamation at the rubbing sites of the skin. The histopathological features of 4 cases were sponge formation, acanthosis and perivascular inflammation in the superficial dermis. Accumulation of neutrophils in the epidermis and the dermis was observed in 2 cases. Patients were treated with the systemic glucocorticoids and cyclosporine, and advised to avoid contact with benzalkonium chloride disinfectant. Conclusions Contact dermatitis caused by benzalkonium chloride disinfectant has specific manifestations and good response to the treatments. The skin patch test would be helpful to confirm the diagnosis

Accelerated start-up and improved performance of wastewater microbial fuel cells in four circuit modes: Role of anodic potential

International audienceWastewater microbial fuel cells (MFCs) can transform the chemical energy into electricity; however, little is known on the effect of circuit modes on start-up and performance of wastewater MFCs. Here we have investigated the effect of four circuit modes on start-up, performance and membrane fouling of MFCs systematically. Besides shortening the start up period and improving the performance of MFCs, applying anodic negative potential also balances pH of the system and thus enhances COD removal. The open-circuit constant potential mode (OC-MFC) presents the shortest start-up period of 5 days, with the highest voltage output of 810 mV and the slightest membrane fouling, which provides an effectively strategy to accelerate the start-up of wastewater MFCs. The circuit mode applied to start up wastewater MFC not only affects the degree of membrane fouling, but also causes significant differences in anode microbial communities. The total abundance of exoelectrogens in the closed-circuit intermittent potential (CI-MFC) mode was the highest up to 54.70%, but the performance of CIMFC inferiors to OC-MFC, indicating that performance of the wastewater MFC is not solely determined by the dominant bacteria. Overall, the OC-MFC provides a new strategy to accelerate the start-up period and enhance performance of wastewater MFC simultaneously

Research Techniques Made Simple: Single-Cell RNA Sequencing and its Applications in Dermatology

RNA sequencing is one of the most highly reliable and reproducible methods of assessing the cell transcriptome. As high-throughput RNA sequencing libraries at the single cell level have recently developed, single cell RNA sequencing has become more feasible and popular in biology research. Single cell RNA sequencing allows investigators to evaluate cell transcriptional profiles at the single cell level. It has become a very useful tool to perform investigations that could not be addressed by other methodologies, such as the assessment of cell-to-cell variation, the identification of rare populations, and the determination of heterogeneity within a cell population. So far, the single cell RNA sequencing technique has been widely applied to embryonic development, immune cell development, and human disease progress and treatment. Here, we describe the history of single cell technology development and its potential application in the field of dermatology

2-O-Methylhonokiol Suppresses HCV Replication via TRAF6-Mediated NF-kB Activation

Hepatitis C virus (HCV) is associated with various liver diseases. Chronic HCV infection is characterized by an abnormal host immune response. Therefore, it is speculated that to suppress HCV, a well-regulated host immune response is necessary. 2-O-methylhonokiol was identified by the screening of anti-HCV compounds using Renilla luciferase assay in Huh 7.5/Con 1 genotype 1b replicon cells. Here, we investigated the mechanism by which 2-O-methylhonokiol treatment inhibits HCV replication using real-time PCR. Our data shows that treatment with 2-O-methylhonokiol activated innate immune responses via nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway. Additionally, the immunoprecipitation result shows that treatment with 2-O-methylhonokiol augmented tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) by preventing p62 from binding to TRAF6, resulting in reduced autophagy caused by HCV. Finally, we reproduced our data with the conditioned media from 2-O-methylhonokiol-treated cells. These findings strongly suggest that 2-O-methylhonokiol enhances the host immune response and suppresses HCV replication via TRAF6-mediated NF-kB activation

Mesenchymal Stem Cells Activate the MEK/ERK Signaling Pathway and Enhance DNA Methylation via DNMT1 in PBMC from Systemic Lupus Erythematosus

The defective MEK/ERK signaling pathway and downstream hypomethylation pattern of lymphocytes are crucial for the pathogenesis of systemic lupus erythematosus (SLE). However, the role that the mesenchymal stem cells play in the MEK/ERK signaling pathway and DNA methylation of peripheral blood mononuclear cells (PBMC) from SLE patients remains unknown. In this study, we found that the MEK/ERK signaling pathway of PBMC from SLE patients was activated after the coculture with bone marrow-derived mesenchymal stem cells (BM-MSC) compared with that from the control group. In addition, the expression level of DNA methyltransferase 1 (DNMT1) increased while the levels of CD70, integrin, alpha L (ITGAL), selectin-l, and IL-13 were reduced in PBMC from SLE patients. However, no obvious effect of BM-MSC on PBMC from healthy controls was observed. These findings revealed that BM-MSC might downregulate the expression of methylation-sensitive genes and then suppress the autoactivated PBMC via the MEK/ERK signaling pathway. And it may be one of the mechanisms that BM-MSC ameliorated SLE