[Inhibitory effect of Glehniae Radix petroleum ether part on TGF-ß1-induced epithelial mesenchymal transition in A549 cells].

To study the inhibitory effect of Glehniae Radix petroleum ether part on TGF-ß1-induced epithelial mesenchymal transition in non-small cell lung cancer A549 and its possible mechanism. With type Ⅱ epithelial cells of lung cancer A549 as the research object, the experiment was performed in 5 µg•L⁻¹ TGF-ß1-induced epithelial mesenchymal transition model,and blank control group, model group and Glehniae Radix petroleum ether group were set up. MTT assay was carried out to detect the effect of petroleum ether extract of Glehniae Radix on the survival of A549 cells. A549 cells induced by TGF-ß1(5 µg•L⁻¹) was intervened by different polar parts of Glehniae Radix, Real-time quantitative polymerase chain reaction(RT-qPCR) was used to analyze mRNA expressions of the epithelial mesenchymal transition markers, such as ColⅠ,E-cadherin,Vimentin and α-SMA. Enzyme linked immunosorbent assay(ELISA) was used to detect hydroxyproline(HYP) level. The migration and invasion abilities of cells were detected through wound scratch assay. According to the experimental results, the petroleum ether extract of Glehniae Radix could inhibit the growth of A549 cells in a concentration-dependent manner. Compared with model group, Glehniae Radix petroleum ether part group could effectively inhibit mRNA expressions of ColⅠ,Vimentin and α-SMA, but improve expression of E-cadherin.Glehniae Radix petroleum ether part could reduce the content of hydroxyproline in cells and inhibit the migration of A549 cells.Therefore, the petroleum ether extract of Glehniae Radix can effectively inhibit the occurrence of epithelial mesenchymal transition induced by TGF-ß1 induced alveolar epithelial cells, and Glehniae Radix petroleum ether part may be a potential drug for idiopathic pulmonary fibrosis. The mechanism may be achieved through the regulation of ColⅠ, Vimentin, α-SMA and E-cadherin.

Median effective effect-site concentration of sufentanil for wake-up test in adolescents undergoing surgery: a randomized trial.

BACKGROUND: To determine the median effective concentration of sufentanil as an analgesic during wake-up tests after sevoflurane anesthesia during surgery for adolescent idiopathic scoliosis (AIS). METHODS: This is a randomised controlled trial. Sixty patients aged 13-18 years scheduled for AIS surgery were randomized into six groups of 10 patients each to receive target effect-site concentrations of sufentanil of 0.19, 0.1809, 0.1723, 0.1641, 0.1563, and 0.1489 ng/ml (target concentration ratio, 1.05). Wake-up time was recorded. Median EC50 and 95% confidence interval (CI) for sufentanil target-controlled infusion (TCI) were determined using Kärber's method. The primary outcome was median EC50 for sufentanil TCI as an analgesic during the wake-up test after sevoflurane anesthesia during surgery for AIS. RESULTS: The EC50 and 95% CI of sufentanil TCI were 0.1682 ng/ml and 0.1641 ~ 0.1724 ng/ml, respectively. CONCLUSIONS: The EC50 of sufentanil TCI was 0.1682 ng/ml (95% CI: 0.1641 ~ 0.1724 ng/ml) during sevoflurane anesthesia in adolescents undergoing surgery for idiopathic scoliosis with intraoperative wake-up tests. TRIAL REGISTRATION: Clinicaltrials.gov identifier: ChiCTR-TTRCC-12002696.

Tuning hydrogen storage in lithium-functionalized BC2N sheets by doping with boron and carbon.

First-principles calculations are used to explore the strong binding of lithium to boron- and carbon-doped BC2N monolayers (BC2NBC and BC2NCN, respectively) without the formation of lithium clusters. In comparison to BC2N and BC2NCB, lithium-decorated BC2NBC and BC2NCN systems possess stronger s-p and p-p hybridization and, hence, the binding energy is higher. Lithium becomes partially positively charged by donating electron density to the more electronegative atoms of the sheet. Attractive van der Waals interactions are responsible for binding hydrogen molecules around the lithium atoms. Each lithium atom can adsorb three hydrogen molecules on both sides of the sheet, with an average hydrogen binding energy of approximately 0.2 eV, which is in the range required for practical applications. The BC2NBC-Li and BC2NCN-Li complexes can serve as high-capacity hydrogen-storage media with gravimetric hydrogen capacities of 9.88 and 9.94 wt %, respectively.

Mechanism for the reaction of 2-naphthol with N-methyl-N-phenyl-hydrazine suggested by the density functional theory investigations.

For the first time the computed mechanisms for the novel reaction of 2-naphthol with N-methyl-N-phenylhydrazine, leading to 1-amino-2-naphthol (Tang et al., J Am Chem Soc 2008, 130, 5840), have been investigated using the density functional theory. Four distinct possible pathways were evaluated: two amination mechanisms with the attack of NH(2) group respectively at the α-position C1 and ß-position C3 atoms of 2-naphthol (pathways 1 and 2) as well as two rearrangement processes with displacement of the phenolic hydroxyl group followed by the benzidine-like rearrangement at the α-position C1 and ß-position C3 atoms of 2-naphthol, respectively (pathways 3 and 4). Solvent effect has been tested based on the optimized geometries of the stationary points in solution at the B3LYP/PCM/6-31+G(d,p) level of theory with an averaged dielectric constant of binary solvent. Single-point energies of the optimized structures have been calculated using three hybrid density functionals, B3LYP, MPW3LYP, and B3PW91 with the 6-311++G(3df,2p) basis set. Our computed results clearly manifest that pathway 1 (α-amination) has the highest possibility to occur, with the Gibbs free energies being lower by 6 to 20 kcal/mol compared with the other three pathways, which leads to 1-amino-2-naphthol and N-methylaniline as products. It is in excellent agreement with the experimental observation.

Quantum mechanics study and Monte Carlo simulation on the hydrolytic deamination of 5-methylcytosine glycol.

The efficient formation of 5-methylcytosine glycol (mCg) and its facile deamination to thymine glycol (Tg) may account for the prevalent C → T transition mutation found at methylated CpG site (mCpG) in human p53 gene, a hallmark for many types of human tumors. In this work, the hydrolytic deamination of mCg was investigated at the MP2 and B3LYP levels of theory using the 6-311G(d,p) basis set. In the gas phase, three pathways were explored, paths A-C, and it indicates that the direct deamination of mCg with H(2)O by either pathway is unlikely because of the high activation free energies involved in the rate-determining steps, the formation of the tetrahedral intermediate for paths A and B as well as the formation of the Tg tautomer for path C. In aqueous solution, the role of the water molecules in the deamination of mCg with H(2)O was analyzed in two separate parts: the direct participation of one water molecule in the reaction pathway, called the water-assisted mechanism; and the complementary participation of the aqueous solvation. The water-assisted mechanism was carried out for mCg and the cluster of two water molecules by quantum mechanical calculations in the gas phase. This indicates that the presence of the auxiliary water molecule significantly contributes to decreasing all the activation free energies. The bulk solution effect on the water-assisted mechanism was included by free energy perturbation implemented on Monte Carlo simulations, which is found to be substantial and decisive in the deamination mechanism of mCg. In this case, the water-assisted path A is the most plausible mechanism reported for the deamination of mCg, where the calculated activation free energy (22.6 kcal mol(-1) at B3LYP level of theory) agrees well with the experimentally determined activation free energy (24.8 kcal mol(-1)). The main striking results of the present DFT computational study which is in agreement with previous experimental data is the higher rate of deamination displayed by mCg residues with respect to 5-methylcytosine (mC) bases, which supports that the deamination of mCg contributes significantly to the C → T transition mutation at mCpG dinucleotide site.

[Effects of astilbin on the expression of TNF alpha and IL-10 in liver warm ischemia-reperfusion injury].

OBJECTIVES: To investigate the effects of astilbin on the expressions of TNF alpha and IL-10 during liver warm ischemia-reperfusion injury. METHODS: C57BL/ 6 mice were randomly divided into 4 groups (n = 8): sham-operated group (Sham), model control group(I/R), low dosage of astilbin treatment group (10 mg/kg) and high dosage of astilbin (40 mg/kg) treatment group. The treatment group mice were intraperitoneally injected with 10 or 40 mg/kg astilbin 24 hours and one hour before Ischemia, the hepatic ischemia-reperfusion model were thus established. After jn90 of min ischemia and 6 h reperfusion of the partial hepatic lobe, the expressions of TNF alpha and IL-10 in liver tissues collected from the experimental groups were detected by Western blot and semiquantitative RT-PCR. RESULTS: The expression of TNF alpha protein in liver tissues gradually decreased in treatment groups (low and high dosages of astilbin treatment groups) as compared to the I/R model control group. Similar results were observed in the mRNA expressions of these genes as determined by semiquantitative RT-PCR (P less than 0.05 for low dosage group; P less than 0.01 for high dosage group). Compared with the I/R model control group, the expression of IL-10 was increased in both treatment groups (low dosage group P less than 0.05; large dosage group P less than 0.01). CONCLUSION: Treatment with astilbin decreases TNF alpha expression but induces IL-10 expression in liver during warm ischemia-reperfusion injury.

Transcriptome sequencing analysis of the MSDIN gene family encoding cyclic peptides in lethal Amanita fuligineoides.

Amanita fuligineoides, a lethal mushroom discovered in China, contains abundant cyclic peptide toxins that can cause fatal poisoning. However, the MSDIN gene family encoding for these cyclic peptides in A. fuligineoides has not been systematically studied. In this research, the transcriptome sequencing of A. fuligineoides was performed and its MSDIN family members were analyzed. A total of 4.41 Gb data containing 30833 unigenes was obtained; sequence alignments throughout several databases were done to obtain their functional annotations. Based on these annotations, MSDIN genes were found and verified by RT-PCR. A total of 29 different core peptides were obtained: 3 toxin genes, encoding ß-amanitin (ß-AMA), phalloidin (PHD), and phallacidin (PCD), and 26 genes encoding unknown cyclic peptides, 20 of which are reported for the first time and may encode for novel cyclic peptides. Analysis of the predicted precursor peptides indicated that octocyclic peptides were the main MSDIN peptides synthesized by A. fuligineoides, accounting for the 45%. A phylogenetic analysis suggested that studied precursor peptides could be clustered into 7 clades, which might represent different functionalities. Results suggested that A. fuligineoides might have a strong capacity to synthesize cyclopeptides, laying the foundation for their excavation and utilization.

Theoretical studies on the thermodynamics and kinetics of the N-glycosidic bond cleavage in deoxythymidine glycol.

The thermodynamic and kinetic properties for the nonenzymatic N-glycosidic bond cleavage in cis-(5R,6S)-5,6-dihydroxy-5,6-dihydrodeoxythymidine (deoxythymidine glycol, dTg) were studied by computational techniques. Optimized structures for all of the stationary points in the gas phase were investigated using the BHandHLYP/6-311++G(d,p) and B3LYP/6-311++G(d,p) methods. Single-point energies were determined employing the ab initio MP2 method in conjunction with the 6-311++G(d,p) basis set. For the unimolecular decomposition of dTg in the gas phase, two pathways were characterized. Subsequently, the hydrolysis of dTg by a single water molecule was investigated. Two possible pathways were considered, involving the abstraction of the C2' hydrogen followed by the attack of water on the C1'=C2' bond (SN1 pathway) and the attack of a water molecule on the C1' atom with the simultaneous cleavage of the glycosidic bond (SN2 pathway). However, both the unimolecular decomposition reaction and the hydrolysis reaction involve large energy barriers, suggesting that the role of water is not beneficial to the overall reaction and the direct involvement of a sole water molecule as a nucleophile is unlikely. This result emphasizes the important catalytic role of enzymes. In addition, the solvent effect of water on the four processes was assessed at the geometry optimization level by means of the conductor-like polarized continuum model. Single-point computation was done at the MP2/6-311++G(d,p)//BHandHLYP/6-311++G(d,p) level. The calculated results show that the presence of the solvent water substantially lowers all energy barriers. Our results give out a greater fundamental understanding of the effects of the nucleophile water and solvent water for this important biological reaction.

Theoretical studies on the water-assisted hydrolysis of N,N-dimethyl-N'-(2',3'-dideoxy-3'-thiacytidine) formamidine with three water molecules.

The water-assisted hydrolysis mechanism of N,N-dimethyl-N'-(2',3'-dideoxy-3'-thiacytidine) formamidine (MFA-3TC) with three water molecules was studied by use of computational techniques. Optimized structures for all of the stationary points in the gas phase were investigated using the B3LYP/6-31+G(d,p) method. Single-point energies were determined employing the ab initio MP2 method in conjunction with the 6-311++G(d,p) basis set. Two possible pathways in the title reaction are considered, involving the attack of water molecule at first to the C(1)=N(1) double bond (path A) and the attack of water molecule at first to the C(1)-N(2) single bond (path B), respectively. A local microhydration model concerning three water molecules is adopted to mimic the system for the two reaction mechanisms above, where one water molecule is the nucleophilic reactant and the others are the auxiliary molecules. The calculated results indicate that the first steps in both pathways are the rate-limiting processes, and path A is more favorable than path B in the gas phase. In addition, bulk solvent effect is tested at the geometry optimization level by means of the conductor-like polarized continuum model (CPCM). Single-point computation was done at the MP2/6-311++G(d,p) level based on the geometries in the solution phase. Our results exhibit that the rate-limiting process in both pathways in water is the first step reaction, and path A is still favored. Two pathways are stepwise and slightly endothermic processes.

Molecular cloning and the expression pattern of AePOPB involved in the α-amanitin biosynthesis in Amanita exitialis fruiting bodies.

Amanita exitialis Zhu L. Yang & T. H. Li is the species responsible for the largest number of mushroom-associated human poisonings and fatalities in South China due to its lethal cyclic peptide toxins. Prolyl oligopeptidase B (POPB) is considered a key enzyme in the production of the highly toxic cyclic peptide α-amanitin. However, the POPB gene of A. exitialis has not been studied. In the present study we cloned and sequenced the full-length A. exitialis POPB (AePOPB) gene. The aim was to verify the gene structure and functions of AePOPB. The full-length sequence of AePOPB is 3144 bp, including 18 exons encoding 730 aa, and the advanced structure is very similar to that of the previously reported POPB in Galerina marginata (GmPOPB). The amino acid sequence of AePOPB is highly homologous with those from other amanitin-producing lethal mushrooms, implying that AePOPB may have a similar role in the biosynthesis of cyclic peptide toxins. Expression levels of AePOPB were detectable in all parts and developmental stages of the fruiting bodies, and AePOPB was expressed more strongly at early development stages (early and late elongation stages). At early and late elongation stages, the expression peaks occurred in the stipe, whereas at early and late mature stages, the expression peaks occurred in the pileus. The expression patterns of AePOPB in different stages and different parts of the fruiting bodies were highly consistent with those of Aeα-AMA, which is required for α-amanitin accumulation. These results indicate that AePOPB should be involved in the α-amanitin biosynthesis in A. exitialis.

Effect of the intraoperative wake-up test in sevoflurane-sufentanil combined anesthesia during adolescent idiopathic scoliosis surgery: a randomized study.

STUDY OBJECTIVE: To investigate the effect of the intraoperative wake-up test on sevoflurane-sufentanil anesthesia for adolescent idiopathic scoliosis (AIS) surgery. DESIGN: Randomized, double-blind, parallel trial. SETTING: Operating room. PATIENTS: 30 ASA physical status 1 patients, aged 13 to 20 years, scheduled for AIS surgery. INTERVENTIONS: Patients were randomized to two groups: Group W patients received sevoflurane-sufentanil combined anesthesia and underwent the intraoperative wake-up test; Group NW received sevoflurane-sufentanil combined anesthesia without the wake-up test. Anesthesia was induced with an intravenous (IV) injection of midazolam, propofol, and sufentanil and maintained with sevoflurane inhalation, a target-controlled infusion (TCI) of sufentanil, and IV infusion of cisatracurium besylate. MEASUREMENTS: The primary outcome was postoperative delirium. Secondary outcomes were duration of surgery, duration of anesthesia, intraoperative blood loss and transfusion, exposure of drugs administered, time to eye opening, extubation, and consciousness. MAIN RESULTS: Postoperative delirium occurred in one patient from each group (P > 0.05). There were no significant differences between the two groups in duration of surgery (322 ± 65 min vs 336 ± 72 min), duration of anesthesia (356 ± 76 min vs 368 ± 81 min), intraoperative blood loss (1847 ± 423 mL vs 1901 ± 451 mL) and transfusion (1663 ± 398 mL vs 1649 ± 382 mL), average exposure of drugs (72 ± 13 mg vs 75 ± 15 mg for propofol, 116 ± 28 µg vs 109 ± 25 µg for sufentanil, and 22 ± 5 vs 23 ± 4 mg for cisatracurium), time to eye opening (4.7 ± 1.5 min vs 4.8 ± 1.4 min), extubation (7.5 ± 2.0 min vs 7.3 ± 2.2 min), and consciousness (8.9 ± 1.8 min vs 9.1 ± 2.1 min) (all P > 0.05). CONCLUSIONS: Sevoflurane-sufentanil combined anesthesia provides hemodynamic stability and rapid recovery from AIS surgery. There is no correlation between the intraoperative wake-up test and postoperative delirium after sevoflurane-sufentanil combined anesthesia.

Molecular dynamics and density functional theory studies of substrate binding and catalysis of human brain aspartoacylase.

The active-site dynamics of human brain aspartoacylase (hASPA) complexed with its substrate (N-acetyl-L-aspartate) has been studied using a hybrid quantum mechanical/molecular mechanical (QM/MM) approach based on the self-consistent charge-density functional tight-binding (SCC-DFTB) model. The Michaelis complex, which is constructed from a recent X-ray structure of the human brain aspartoacylase with a stable tetrahedral intermediate analogue, is reproduced in 1ns molecular dynamics simulations at 300K. The simulation shows that the substrate is tightly held in the active site by a hydrogen bond network and the putative nucleophilic water molecule is reasonably close to the nucleophilic center. The catalysis is further modeled with the density functional theory (DFT) in a truncated active-site model at the B3LYP/6-31G(d) level of theory. The DFT calculations indicate the reaction proceeds via a water promoted pathway with Glu178 serving as the general base and general acid. Transition state stabilization for nucleophilic addition is achieved by formations of the weak coordination bond between the substrate carbonyl oxygen atom and the zinc ion as well as of the strong hydrogen bonds between the substrate carbonyl oxygen atom and Arg63.

[Effect of intra-abdominal pressure on respiratory system, circulatory system and renal function in rats and study on the method of determination of intra-abdominal pressure].

UNLABELLED: OBJECTIVE To study the effects of intra-abdominal pressure (IAP) on respiratory system, circulatory system and renal function in rats. To investigate the difference between the direct measure and indirect measure methods (via inferior vena cava and bladder) for IAP. METHODS: Sixty Sprague-Drawly (SD) rats were randomly divided into 5 groups with different IAP (IAP value of 1-5 groups was 5, 10, 15, 20, 25 mm Hg,respectively) and healthy control group, 10 rats in each group. The parameters of respiratory system, circulatory system, renal function, and IAP value were recorded. The correlation between direct and indirect measurement methods was also analyzed. RESULTS: There were no significant differences in above parameters between IAPI and healthy control groups. Compared with those in healthy control group, PaO2 significantly decreased (P < 0.05), SCr and BUN increased significantly in IAP2 group (P < 0.05). Other indexes in IAP3, IAP4 groups increased (P < 0.05 or P < 0.01) except for respiratory frequency(RF) and MAP (P > 0.05). PaO2 and MAP decreased (P < 0.01), and other indexes increased (P < 0.05 or P < 0.01) in IAP5 group. The values obtained from the indirect measure method were positively correlated with that from the direct measure method (r = 0.937, 0.955, P < 0.01, respectively). CONCLUSIONS: IAP can affect respiratory system, circulatory system and renal function in different degrees in rats. The indirect measure method can replace the direct measure method for IAP measure with little injuries.