Cytotoxic effects and the mechanism of three types of magnetic nanoparticles on human hepatoma BEL-7402 cells

The evaluation of the toxicity of magnetic nanoparticles (MNPs) has attracted much attention in recent years. The current study aimed to investigate the cytotoxic effects of Fe3O4, oleic acid-coated Fe3O4 (OA-Fe3O4), and carbon-coated Fe (C-Fe) nanoparticles on human hepatoma BEL-7402 cells and the mechanisms. WST-1 assay demonstrated that the cytotoxicity of three types of MNPs was in a dose-dependent manner. G1 (Fe3O4 and OA-Fe3O4) phase and G2 (C-Fe) phase cell arrests and apoptosis induced by MNPs were detected by flow cytometry analysis. The increase in apoptosis was accompanied with the Bax over-expression, mitochondrial membrane potential decrease, and the release of cytochrome C from mitochondria into cytosol. Moreover, apoptosis was further confirmed by morphological and biochemical hallmarks, such as swollen mitochondria with lysing cristae and caspase-3 activation. Our results revealed that certain concentrations of the three types of MNPs affect BEL-7402 cells viability via cell arrest and inducing apoptosis, and the MNPs-induced apoptosis is mediated through the mitochondrial-dependent pathway. The influence potency of MNPs observed in all experiments would be: C-Fe > Fe3O4 > OA-Fe3O4

Research on the Countermeasures of Military Equipment Instructors’ Teaching Ability Construction in the New Era

According to the requirements of military education policy in the new era, military equipment instructors must constantly strengthen the construction of teaching ability in order to provide professional equipment technical personnel for the new information war in the future. In view of how to comprehensively improve the teaching ability of military equipment instructors, this paper first analyses the main problems existing in the current teaching ability construction of equipment instructors in our Institute, and then puts forward some specific measures to strengthen the teaching ability construction of equipment instructors, which has certain guidance and reference for rapidly and efficiently improving the actual combat teaching ability of equipment instructors

Functional variant of the carboxypeptidase M (CPM) gene may affect silica-related pneumoconiosis susceptibility by its expression: a multistage case-control study.

ObjectivesIn a genome-wide association study, we discovered chromosome 12q15 (defined as rs73329476) as a silica-related pneumoconiosis susceptibility region. However, the causal variants in this region have not yet been reported.MethodsWe systematically screened eight potentially functional single-neucleotide polymorphism (SNPs) in the genes near rs73329476 (carboxypeptidase M (CPM) and cleavage and polyadenylation specific factor 6 (CPSF6)) in a case-control study including 177 cases with silicosis and 204 healthy controls, matched to cases with years of silica dust exposure. We evaluated the associations between these eight SNPs and the development of silicosis. Luciferase reporter gene assays were performed to test the effects of selected SNP on the activity of CPM in the promoter. In addition, a two-stage case-control study was performed to investigate the expression differences of the two genes in peripheral blood leucocytes from a total of 64 cases with silicosis and 64 healthy controls with similar years of silica dust exposure as the cases.ResultsWe found a strong association between the mutant rs12812500 G allele and the susceptibility of silicosis (OR=1.45, 95% CI 1.03 to 2.04, p=0.034), while luciferase reporter gene assays indicated that the mutant G allele of rs12812500 is strongly associated with increased luciferase levels compared with the wild-type C allele (p<0.01). Moreover, the mRNA (peripheral blood leucocytes) expression of the CPM gene was significantly higher in subjects with silicosis compared with healthy controls.ConclusionsThe rs12812500 variant of the CPM gene may increase silicosis susceptibility by affecting the expression of CPM, which may contribute to silicosis susceptibility with biological plausibility

Toxicity study of oral vanadyl sulfate by NMR-based metabonomic

Vanadium compounds have been believed to be ideal drugs for diabetes biological therapy in future, but they suffer setback for the potential toxicity now. Toxicity study is necessary for vanadyl drugs development. This paper investigated the toxicity effects of vanadyl sulfate (VOSO4) oral administration in male Wistar rats using H-1 NMR-based metabonomic analysis and clinical biochemical analysis. Rat urine were collected and their H-1 NMR spectra were acquired, and then subjected to multi-variable statistical analysis. Compared to control groups, urinary excretion of lactate, TMAO, creatinine, taurine and hippurate increased following VOSO4 dosing, with concomitant decrease in the level of acetate and succinate. The dosed groups can be readily discriminated from the control groups by principle component analysis. The results showed that VOSO4 can affect energy metabolism process, interrupted intestinal microfloral metabolism, and induced liver and kidney injury. NMR-based metabonomic can offer additional information to traditional clinical chemistry in the sensitivity and specificity of results obtained

Biomolecule-assisted synthesis of 3D structure gold nanocrystals in the presence of cystamine dihydrochloride or cysteamine

A facile cystamine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D gold litchi-like nanostructures. By controlling reaction conditions such as the molar ratio between HAuCl(4) and cystamine dihydrochloride and the reaction time, the synthesis of various 3D architectural structures and 1D structure in large quantities can be controlled. The formation mechanism for the gold litchi-like assemblies with well-arranged nanorods was also discussed. In addition, as the control test, featheriness gold structures were obtained through using cysteamine as the assisted agent. On the basis of the results from SEM studies and our analysis, we speculate that the different morphologies obtained by cystamine dihydrochloride and cysteamine due to the Au-S interaction. These differences in hydrogen storage capacity are likely due to the size and density of space/pores as well as the morphology of different nanostructures. This facile, environmentally benign, and - solution-phase biomolecule-assisted method can be potentially extended to the preparation of other metal nanostructures

Heme oxygenase induction confers cellular adaptive response against multi-walled carbon nanotubes-induced cytotoxicity in A549 cell

Carbon nanotubes currently attract intense attention for various biomedical applications due to their large surface areas, high electrical conductivity, and excellent strength. However, these attractive properties of nanomaterials are also the main factors for their potential toxicity. The present study was undertaken to determine the toxicity exhibited by multi-walled carbon nanotubes (MWCNT) in A549 lung epithelial cells. Treatment with increasing doses of MWCNT decreased the cell viability. The glutathione concentration decreased and intracellular reactive oxygen species (ROS) increased in a dose- and time-dependent manner, suggesting that the cytotoxicity on A549 cells was due to oxidative stress. Expression of heme oxygenase (HO)-1, a redox regulator and heat shock protein, increased with dose after MWCNT treatment. Pretreated with zinc protoporphyrin IX (ZnPP IX), a competitive HO inhibitor, underwent cell viability decrease and ROS accumulation increase to a greater extent than cells with MWCNT treatment alone, but these effects were reversed by co-treatment with bilirubin, a product of HO catalysis. Taken together, these findings suggest that MWCNT induce oxidative stress and HO-1 expression in A549 cells, and HO-1 induction may confer a cellular adaptive response against MWCNT-induced cytotoxicity

Exploiting the roles of nitrogen sources for HEA increment in Cordyceps cicadae

Cordyceps cicadae, as a new food ingredient, is a valuable edible and medicinal fungi. However, its resources are severely depleted due to environmental limitations and excessive harvesting practices. N6-(2-hydroxyethyl) adenosine (HEA), as an important product of Cordyceps cicadae, has the potential to be used in medical industry due to its diverse disease curing potential. However, the disclosure of HEA synthesis still severely limited its application until now. In this study, the kinetic curves for adenosine and HEA under shaker fermentation were explored. The kinetics of HEA and adenosine production exhibited a competitive pattern, implicating a possibility of sharing a same step during their synthesis. Due to HEA as a derivative of nitrogen metabolism, the effect of different nitrogen sources (peptone, yeast extract, ammonium sulfate, diammonium oxalate monohydrate, ammonium citrate dibasic, and ammonium citrate tribasic) on HEA production in Cordyceps cicadae strain AH 10-4 had been explored under different incubation conditions (shaker fermentation, stationary fermentation, and submerged fermentation). Our results indicated that the complex organic nitrogen sources were found to improve the accumulation of HEA content under shaker fermentation. In contrast, the optimal nitrogen source for the accumulation of HEA under stationary fermentation and submerged fermentation was ammonium citrate tribasic. But submerged fermentation obviously shortened the incubation time and had a comparable capacity of HEA accumulation by 2.578 mg/g compared with stationary fermentation of 2.535 mg/g, implicating a possibility of scaled-up production of HEA in industry by submerged fermentation. Based on the dramatic HEA production by ammonium sulfate as nitrogen resources between stationary and shaker fermentations, alanine, aspartate and glutamate as well as arginine metabolic pathway were related to the production of HEA by comparative transcriptome. Further investigation indicated that glutamic acid, which is an analog of Asp, showed an optimum production of HEA in comparison with other amino acids

Preparation and characterization of PLA ultrasound contrast agents by combining an ultrasound method and a Shirasu Porous Glass (SPG) membrane emulsification technique

The ultrasound contrast agent based on a poly lactic acid (PLA) was prepared by combining an ultrasound method and a Shirasu Porous Glass (SPG) membrane emulsification technique. An aqueous phase containing ammonium bicarbonate was used as the internal water phase (WO, and PLA and Span 80 were dissolved in a solvent of dichloromethane (DCM), which was used as the oil phase (0). These two solutions were probe sonicated to form a W(1)/O primary emulstion. The primary emulsion was permeated through the uniform pores (1.1 mu m) of an SPG membrane into the external water phase (W(2)) by the pressure of nitrogen gas to form the uiniform W(1)/O/W(2) droplets. After DCM was evaporated, the hardened PLA microcapsules were further formulated into a lyophilized powder containing decafluorobutane gas. SEM image demonstrated that the PLA microcapsules were sphere-shaped and internally hollow with an average diameter ranging from 1.99 to 3.58 mu m. In vitro, the PLA contrast agents showed high acoustic enhancement properties, the enhancement increased nonlinearly with dose, and the minimal loss (less than 5 dB) of signal was observed over 20 min of analysis at 37 degrees C, the maximum acoustic enhancement was 45 dB, which significantly higher (p<0.01) compared to a value of 28 dB for those prepared by a conventional solvent evaporation method. In conclusion, the hollow PLA microcapsules prepared by the novel method have the characteristics desirable for an intravenously administered ultrasound contrast agents

Effect of pH on the Interaction of Gold Nanoparticles with DNA and Application in the Detection of Human p53 Gene Mutation

Science and Technology Innovation Project of Fujian Province for Young Scientific Researchers, China [2006F3128]; Open Fund of State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University [200602]Gold nanoparticles (GNPs) are widely used to detect DNA. We studied the effect of pH on the assembly/disassembly of single-stranded DNA functionalized GNPs. Based on the different binding affinities of DNA to GNPs, we present a simple and fast way that uses HCl to drive the assembly of GNPs for detection of DNA sequences with single nucleotide differences. The assembly is reversible and can be switched by changing the solution pH. No covalent modification of DNA or GNP surface is needed. Oligonucleotide derived from human p53 gene with one-base substitution can be distinguished by a color change of the GNPs solution or a significant difference of the maximum absorption wavelength (lambda(max)), compared with wildtype sequences. This method enables detection of 10 picomole quantities of target DNA