An activatable small-molecule fluorogenic probe for detection and quantification of beta-amyloid aggregates.

Extracellular accumulation of ß amyloid (Aß) peptides in the brain is thought to be a pathological hallmark and initial event before the symptom starts of Alzheimer's patients. Herein, we developed two series of benzo[d]thiazole-based small-molecule compounds (BM1-BM4, BPM1-BPM4) with a donor-acceptor (D-A) or donor-π-acceptor (D-π-A) architecture, respectively, based on structure-activity relationship. Among them, the optimized BPM1 not only displayed the highest binding affinity to Aß aggregates over other proteins or Aß monomers, but was readily activated its fluorescence with 10-fold fluorescence enhancement, allowing for specifically and sensitively detecting Aß aggregates. BPM1 also exhibits several other advantages including low molecular weight, low cytotoxicity and excellent biological stability. Besides, cell staining results confirmed that SK-N-BE(2) cells can be fluorescently lighted up as well as cell permeability and damage when treated with BPM1-bound Aß1-42 aggregates.

[Applicability of Seven Glomerular Filtration Rate Evaluation Formulas in Dose Adjustment of High Concentration of Methotrexate Chemotherapy in Children with ALL].

OBJECTIVE: To investigate the diagnostic efficacy of seven glomerular filtration rate (GFR) evaluation formulas Schwartz2009, Schwartz1976, Counahan-Barratt, Filler, CKD-EPIscysc, Cockrofi-Gault, CKD-EPIScysC-Scr in high concentration of methotrexate (HDMTX) chemotherapy dose adjusted cut-off point (GFR ≤85 ml/min) in children with acute lymphoblastic leukemia (ALL). METHODS: One hundred and twenty-four children with ALL were included in the study. GFR determined by renal dynamic imaging (sGFR) was used as the standard to evaluate the accuracy, consistency of eGFR calculated by seven formulas and sGFR, and the diagnostic efficacy of each formula when the sGFR ≤85 ml/min boundary. RESULTS: All of the accuracy of eGFR estimated by Schwartz2009 were greater than 70% in the 0-3, >4 and ≤6, >6 and ≤9, >9 and ≤16 years old group and male group, and the consistency exceeded the professional threshold. When the sensitivity of the ROC curve sGFR ≤85 ml/min was 100% of CKD-EPIscysc in the 0-3, >3 and ≤4 years old group, Filler in the >3 and ≤4 years old group, and Cockrofi-Gault in the >6 and ≤9 years old group, the specificity was 73.02%, 78.95%, 78.95%, 69.32%, respectively, and the AUC under the ROC curve was the largest (P<0.05). CONCLUSION: Schwartz2009 formula predicts the highest accuracy of eGFR in the 7 glomerular filtration rate. CKD-EPIscysc, Filler, and Cockrofi-Gault formulas have more guiding signi-ficance for the adjustment of HDMTX chemotherapy in pre-adolescence in children with ALL when sGFR ≤85 ml/min.

Chemometrics-assisted analysis of chemical impurity profiles of tabun nerve agent using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

A route determination strategy through non-targeted screening of chemical attribution signatures was developed to identify tabun samples from three different synthetic routes. The CAS profiles of tabun samples were obtained by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometer (GC×GC-TOFMS). The structures of 109 CAS were identified by NIST library and mass spectrometry fragment analysis. A few identified compounds could be traced to impurities in precursor compounds used in tabun synthesis. Based on the gas chromatography/mass spectrometry peak data of the selected CAS, partial least squares-discriminant analysis (PLS-DA) was used to extract the chemical attribution signatures of the characteristic compounds. The trained PLS-DA model performed well, with the lowest specificity and sensitivity values of 1.000 and 0.882, respectively. The performance of the PLS-DA model was further verified by unknown sample test set. The model demonstrated its ability to differentiate all the unknown tabun samples. The stability of chemical attribution signatures from different time periods was also investigated, and was further evaluated.

m5C Regulator-Mediated Methylation Modification Patterns and Tumor Microenvironment Infiltration Characterization in Papillary Thyroid Carcinoma.

Recently, immune response modulation at the epigenetic level is illustrated in studies, but the possible function of RNA 5-methylcytosine (m5C) modification in cell infiltration within the tumor microenvironment (TME) is still unclear. Three different m5C modification patterns were identified, and high differentiation degree was observed in the cell infiltration features within TME under the above three identified patterns. A low m5C-score, which was reflected in the activated immunity, predicted the relatively favorable prognostic outcome. A small amount of effective immune infiltration was seen in the high m5C-score subtype, indicating the dismal patient survival. Our study constructed a diagnostic model using the 10 signature genes highly related to the m5C-score, discovered that the model exhibited high diagnostic accuracy for PTC, and screened out five potential drugs for PTC based on this m5C-score model. m5C modification exerts an important part in forming the TME complexity and diversity. It is valuable to evaluate the m5C modification patterns in single tumors, so as to enhance our understanding towards the infiltration characterization in TME.

Elongator promotes the migration and invasion of hepatocellular carcinoma cell by the phosphorylation of AKT.

The Elongator is a complex with multiple subunits (Elp1-Elp6) which promotes transcript elongation and protein translation. In this study, we investigated the effects of Elongator on the migration and invasion of HCC cells as well as the underlying mechanisms. We showed that overexpression of Elp3 or Elp4 promoted the migration and invasion of HCC cells, which was abolished when either Elp3 or Elp4 was silenced. The expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 were enhanced by phosphorylation of AKT. Elongator-driven migration and invasion and the expression of MMP-2 and MMP-9 were reduced in HCC cells treated with AKT inhibitor LY294002. Depletion of Elp3 also reduced the phosphorylation of AKT induced by growth factors. In vivo assay of lung metastasis in mice demonstrated that overexpression of Elp3 increased tumor nodules metastatic to lung. Importantly, Elp3 was up-regulated in human HCC tissues, which was correlated with the phosphorylation of AKT and expression of MMP-2. Collectively, these results suggested that Elongator activated migration and invasion of HCC cells by promoting the expression of MMP-2 and MMP-9 through the PI3K/AKT signaling pathway. Our work suggests that Elongator might be a potential marker which promotes the metastasis of HCC.

Angiogenic factors are associated with development of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Acute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-ß in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-ß promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.

Umbilical cord blood-derived mesenchymal stem cells ameliorate graft-versus-host disease following allogeneic hematopoietic stem cell transplantation through multiple immunoregulations.

Although mesenchymal stem cells (MSCs) are increasingly used to treat graft-versus-host disease (GVHD), their immune regulatory mechanism in the process is elusive. The present study aimed to investigate the curative effect of third-party umbilical cord blood-derived human MSCs (UCB-hMSCs) on GVHD patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their immune regulatory mechanism. Twenty-four refractory GVHD patients after allo-HSCT were treated with UCB-hMSCs. Immune cells including T lymphocyte subsets, NK cells, Treg cells and dendritic cells (DCs) and cytokines including interleukin-17 (IL-17) and tumor necrosis factor-alpha (TNF-α) were monitored before and after MSCs transfusion. The results showed that the symptoms of GVHD were alleviated significantly without increased relapse of primary disease and transplant-related complications after MSCs transfusion. The number of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) cells decreased significantly, and that of NK cells remained unchanged, whereas the number of CD4(+) and CD8(+) Tregs increased and reached a peak at 4 weeks; the number of mature DCs, and the levels of TNF-α and IL-17 decreased and reached a trough at 2 weeks. It was concluded that MSCs ameliorate GVHD and spare GVL effect via immunoregulations.

A Highly Stereoselective Metal-Free Hydrogenation of Diimines for the Synthesis of Cis-Vicinal Diamines.

A highly stereoselective metal-free hydrogenation of vicinal diimines has been successfully realized for the first time using 5-10 mol % of Piers' borane as a catalyst under mild conditions, and a variety of cis-1,2-diamines were obtained in 92-99% yields. The current work provides a novel and efficient approach for the synthesis of vicinal diamines.

A chiral borane catalyzed asymmetric hydrosilylation of imines.

An enantioselective hydrosilylation of imines was successfully achieved using a chiral borane catalyst generated by the in situ hydroboration of a binaphthyl-based chiral diene with Piers' borane HB(C6F5)2 to furnish a variety of optically active amines in 70% to >99% yields and 44-82% ees.