A green and effective method for the determination of metalaxyl enantiomers in tobacco and soil by supercritical fluid chromatography–tandem mass spectrometry

We reported a new methodology for the stereoselective determination of metalaxyl enantiomers in tobacco and soil. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for the extraction and clean-up of the tobacco and soil samples. Separation of the metalaxyl enantiomers was performed on an ACQUITY UPC2 Trefoil CEL1 chiral column coupled with supercritical fluid chromatography with tandem mass spectrometry (SFC-MS/MS), and the run time was only 5 minutes. Under the optimized conditions, the recoveries for the enantiomers were between 78.2% and 93.3% with intraday relative standard deviations (RSDs) ranging from 1.1% to 5.4%. The limit of detection (LOD) for the enantiomers in tobacco and soil varied from 0.005 to 0.007 mg/kg, and the limit of quantitation (LOQ) ranged from 0.017 to 0.020 mg/kg. In this method, only a small amount of methanol was consumed to obtain a rapid stereoselective separation. This proposed method showed good accuracy and precision and might be suitable for fast enantioselective determination of metalaxyl in food and environmental samples. The developed method was further validated by application to the analysis of authentic samples.     

Effect of silicon-doped calcium phosphate cement on angiogenesis based on controlled macrophage polarization

Vascularization is an important early indicator of osteogenesis involving biomaterials.Bone repair and new bone formation are associated with extensive neovascu...     

Allopurinol reduces oxidative stress and activates Nrf2/p62 to attenuate diabetic cardiomyopathy in rats

Allopurinol (ALP) attenuates oxidative stress and diabetic cardiomyopathy (DCM), but the mechanism is unclear. Activation of nuclear factor erythroid 2‐related factor 2 (Nrf2) following the disassociation with its repressor Keap1 under oxidative stress can maintain inner redox homeostasis and attenuate DCM with concomitant attenuation of autophagy. We postulated that ALP treatment may activate Nrf2 to mitigate autophagy over‐activation and consequently attenuate DCM. Streptozotocin‐induced type 1 diabetic rats were untreated or treated with ALP (100 mg/kg/d) for 4 weeks and terminated after heart function measurements by echocardiography and pressure‐volume conductance system. Cardiomyocyte H9C2 cells infected with Nrf2 siRNA or not were incubated with high glucose (HG, 25 mmol/L) concomitantly with ALP treatment. Cell viability, lactate dehydrogenase, 15‐F2t‐Isoprostane and superoxide dismutase (SOD) were measured with colorimetric enzyme‐linked immunosorbent assays. ROS, apoptosis, was assessed by dihydroethidium staining and TUNEL, respectively. The Western blot and qRT‐PCR were used to assess protein and mRNA variations. Diabetic rats showed significant reductions in heart rate (HR), left ventricular eject fraction (LVEF), stroke work (SW) and cardiac output (CO), left ventricular end‐systolic volume (LVVs) as compared to non‐diabetic control and ALP improved or normalized HR, LVEF, SW, CO and LVVs in diabetic rats (all P < .05). Hearts of diabetic rats displayed excessive oxidative stress manifested as increased levels of 15‐F2t‐Isoprostane and superoxide anion production, increased apoptotic cell death and cardiomyocytes autophagy that were concomitant with reduced expressions of Nrf2, heme oxygenase‐1 (HO‐1) and Keap1. ALP reverted all the above‐mentioned diabetes‐induced biochemical changes except that it did not affect the levels of Keap1. In vitro, ALP increased Nrf2 and reduced the hyperglycaemia‐induced increases of H9C2 cardiomyocyte hypertrophy, oxidative stress, apoptosis and autophagy, and enhanced cellular viability. Nrf2 gene silence cancelled these protective effects of ALP in H9C2 cells. Activation of Nrf2 subsequent to the suppression of Keap1 and the mitigation of autophagy over‐activation may represent major mechanisms whereby ALP attenuates DCM.     

Extracellular nanovesicles‐transmitted circular RNA has_circ_0000190 suppresses osteosarcoma progression

Under the microenvironment, tumour progression is substantially affected by cell‐cell communication. In spite of the mediating effect of extracellular nanovesicles (EVs) on cell‐cell communication by packaging into circRNAs, the effect of EVs circRNA hsa_circ_0000190 (circ‐0000190) in osteosarcoma is still not clear. Circ‐0000190 expressions in tissues and EVs from plasma were compared between osteosarcoma patients and controls. Thereafter, receiver operating characteristic (ROC) curve was drawn and area under the curve was calculated to examine whether the diagnostic results were accurate, and the effect of EVs circ‐0000190 was dug out via the determination of cell phenotypes and animal assays. Results showed circ‐0000190 exhibited an obvious reduction in EVs and tissues of osteosarcoma patients (P < .05). It was also discovered that EVs encapsulated the majority of circ‐0000190, and EVs‐encapsulated circ‐0000190 could be applied to make a distinction between osteosarcoma patients and controls. Besides, EVs circ‐0000190 in osteosarcoma cells transported from normal cells weakened the capacities of osteosarcoma cells to migrate, proliferate and invade, so as to block their biological malignant behaviours (P < .05). In addition, under the action of EVs circ‐0000190, tumour growth was impeded and the expression of TET1 was inhibited via the competitive binding to miR‐767‐5p. In all, EVs circ‐0000190 has a good prospect as it can be regarded as a new biomarker for detecting osteosarcoma. EVs circ‐0000190 transported from normal cells to osteosarcoma cells impeded the in vitro and in vivo development of osteosarcoma, implying that EVs circ‐0000190 exerts an effect on communication between normal cells and osteosarcoma cells in the carcinogenesis process of osteosarcoma.     

In Vitro Effects of Ginseng and the Seed of Zizyphus jujuba var. spinosa on Gut Microbiota of Rats with Spleen Deficiency

Ginseng and the seed of Zizyphus jujuba var. spinosa, which are traditional Chinese medicinal materials, were often used in ancient Chinese recipes as a pair of medicines. They can replenish the primordial qi and tonify the spleen. This study investigated the effects of ginseng and the seed of Zizyphus jujuba var. spinosa (GS) extract on gut microbiota diversity in rats with spleen deficiency syndrome (SDS). A total of 52 compounds (including 16 flavonoids, 35 saponins, and 1 alkaloid) were identified and analyzed from the GS extract by UPLC‐Q‐Orbitrap‐MS/MS. The GS extract significantly increased the relative abundance of Firmicutes and Bacteroidetes in rats with SDS but decreased that of Proteobacteria and Actinobacteria. At the genus level, the GS extract significantly increased the relative abundance of Lactobacillus and Bifidobacterium in rats with SDS but decreased that of Streptococcus, Escherichia‐Shigella, Veillonella, and Enterococcus. In addition, the GS extract influenced glucose and amino acid metabolism. In summary, the results showed that the GS extract changed the structure and diversity of gut microbiota in rats with SDS and balanced the metabolic process.     

Study on the Interaction between the Inclusion Complex of Hematoxylin with β-Cyclodextrin and DNA

Ultraviolet-visible (UV-vis) spectra, fluorescence spectra, electrochemistry, and the thermodynamic method were used to discuss the interaction mode between the inclusion complex of hematoxylin with β-cyclodextrin and herring sperm DNA. On the condition of physiological pH, the result showed that hematoxylin and β-cyclodextrin formed an inclusion complex with binding ratio n_hematoxylin:n_{β-cyclodextrin} = 1:1. The interaction mode between β-cyclodextrin-hematoxylin and DNA was a mixed binding, which contained intercalation and electrostatic mode. The binding ratio between β-cyclodextrin-hematoxylin and DNA was n_{β-cyclodextrin -hematoxylin}:n_DNA = 2:1, binding constant was K^? _298.15K = 5.29 × 10⁴ L·mol^?1, and entropy worked as driven force in this action.     

T Cell-Specific Overexpression of TGF?1 Fails to Influence Atherosclerosis in ApoE-Deficient Mice

Clinical data have indicated a negative correlation between plasma TGFß1 concentrations and the extent of atherosclerosis and have thus led to the hypothesis that the pleiotropic cytokine may have anti-atherogenic properties. T-cells are currently discussed to significantly participate in atherogenesis, but the precise role of adaptive immunity in atherogenesis remains to be elucidated. TGFß1 is known to strongly modulate the function of T-cells, however, inhibition of TGFß1 signalling in T-cells of atherosclerosis-prone knock-out mice failed to unequivocally clarify the role of the cytokine for the development of atherosclerosis. In the present study, we thus tried to specify the role of TGFß1 in atherogenesis by using the murine CD2-TGFß1 transgenic strain which represents a well characterized model of T-cell specific TGFß1 overexpression. The CD2-TGFß1 transgenic mice were crossed to ApoE knock-out mice and quantity and quality of atherosclerosis regarding number of macrophages, smooth muscle cells, CD3 positive T-cells and collagen was analyzed in CD2-TGFß1 ApoE double mutants as well as non-transgenic ApoE controls on both normal and atherogenic diet of a duration of 8, 16 or 24 weeks, respectively. In all experimental groups investigated, we failed to detect any influence of TGFß1 overexpression on disease. Total number of CD3-positive T-lymphocytes was not significantly different in atherosclerotic lesions of CD2-TGFß1 ApoE^−/− females and isogenic ApoE^−/− controls, even after 24 weeks on the atherogenic diet. The synopsis of these data and our previous study on TGFß1 overexpressing macrophages suggests that potential effects of TGFß1 on atherosclerosis are most probably mediated by macrophages rather than T-cells.