Synthetic antimicrobial agents inhibit aflatoxin production.

Antimicrobial peptides (AMPs) are biologically active molecules that can eradicate bacteria by destroying the bacterial membrane structure, causing the bacteria to rupture. However, little is known about the extent and effect of AMPs on filamentous fungi. In this study, we synthesized small molecular polypeptides by an inexpensive heat conjugation approach and examined their effects on the growth of Aspergillus flavus and its secondary metabolism. The antimicrobial agents significantly inhibited aflatoxin production, conidiation, and sclerotia formation in A. flavus. Furthermore, we found that the expression of aflatoxin structural genes was significantly inhibited, and the intracellular reactive oxygen species (ROS) level was reduced. Additionally, the antimicrobial agents can change membrane permeability. Overall, our results demonstrated that antimicrobial agents, safe to mammalian cells, have an obvious impact on aflatoxin production, which indicated that antimicrobial agents may be adopted as a new generation of potential agents for controlling aflatoxin contamination.

Value of elastography point quantification in improving the diagnostic accuracy of early diabetic kidney disease.

BACKGROUND: Diabetic kidney disease (DKD) is a common complication of diabetes. The patient's prognosis is poor once DKD progresses to advanced stage. Accurate diagnosis and timely treatment of early DKD are important for improving patient's prognosis and reducing mortality. AIM: To explore the value of elastography point quantification (ElastPQ) in improving the accuracy of early DKD diagnosis. METHODS: A total of 69 patients with type 2 diabetes were recruited from Naval Military Medical University Affiliated Gongli Hospital. Patients were divided into early DKD group and medium DKD group according to pathological results and urinary albumin excretion rate (UAER). Another 40 patients with simple diabetes were included as the diabetes group. The baseline data, laboratory diagnostic indicators, and ultrasound indicators for each patient were recorded. The differences of the indicators in the three groups were compared. Multivariate logistic regression was used to analyze the influencing factors of the development from simple diabetes into early DKD and from early DKD into medium DKD. Receiver operating characteristic analyses of potential indicators in identifying early DKD and medium DKD, and early DKD and simple diabetes were established. RESULTS: Multivariate logistic regression analysis showed that UAER (P < 0.001), renocortical Young's Modulus (YM) (P < 0.001), and renal parenchymal thickness (P = 0.013) were the independent influencing factors of the development from early DKD into medium DKD. Diabetes duration (P = 0.041), UAER (P = 0.034), and renocortical YM (P = 0.017) were the independent influencing factors of the development from simple diabetes into early DKD. Receiver operating characteristic analysis indicated that UAER, renocortical YM, and renal parenchymal thickness were accurate in identifying early DKD and medium DKD [all area under curve (AUC) > 0.9]. The accuracy of UAER (AUC = 0.744), diabetes duration (AUC = 0.757), and renocortical YM (AUC = 0.782) for the diagnosis of early DKD and simple diabetes were limited. However, the combined diagnosis of UAER, diabetes duration, and renocortical YM was accurate in identifying early DKD and simple diabetes (AUC = 0.906), which was significantly higher than any of the three indicators (all P < 0.05). CONCLUSION: ElastPQ is of great value in the diagnosis of early DKD. When combined with the diabetes duration and UAER, it is expected to diagnose accurately early DKD.

Wall shear stress can improve prediction accuracy for transient ischemic attack.

BACKGROUND: Early prediction of transient ischemic attack (TIA) has important clinical value. To date, systematic studies on clinical, biochemical, and imaging indicators related to carotid atherosclerosis have been carried out to predict the occurrence of TIA. However, their prediction accuracy is limited. AIM: To explore the role of combining wall shear stress (WSS) with conventional predictive indicators in improving the accuracy of TIA prediction. METHODS: A total of 250 patients with atherosclerosis who underwent carotid ultrasonography at Naval Military Medical University Affiliated Gongli Hospital were recruited. Plaque location, plaque properties, stenosis rate, peak systolic velocity, and end diastolic velocity were measured and recorded. The WSS distribution map of the proximal and distal ends of the plaque shoulder was drawn using the shear stress quantitative analysis software, and the average values of WSS were recorded. The laboratory indicators of the subjects were recorded. The patients were followed for 4 years. Patients with TIA were included in a TIA group and the remaining patients were included in a control group. The clinical data, laboratory indicators, and ultrasound characteristics of the two groups were analyzed. Survival curves were plotted by the Kaplan-Meier method. Receiver operating characteristic curves were established to evaluate the accuracy of potential indicators in predicting TIA. Logistic regression model was used to establish combined prediction, and the accuracy of combined predictive indicators for TIA was explored. RESULTS: The intraclass correlation coefficients of the WSS between the proximal and distal ends of the plaque shoulder were 0.976 and 0.993, respectively, which indicated an excellent agreement. At the end of the follow-up, 30 patients suffered TIA (TIA group) and 204 patients did not (control group). Hypertension (P = 0.037), diabetes (P = 0.026), homocysteine (Hcy) (P = 0.022), fasting blood glucose (P = 0.034), plaque properties (P = 0.000), luminal stenosis rate (P = 0.000), and proximal end WSS (P = 0.000) were independent influencing factors for TIA during follow-up. The accuracy of each indicator for predicting TIA individually was not high (area under the curve [AUC] < 0.9). The accuracy of the combined indicator including WSS (AUC = 0.944) was significantly higher than that of the combined indicator without WSS (AUC = 0.856) in predicting TIA (z = 2.177, P = 0.030). The sensitivity and specificity of the combined indicator including WSS were 86.67% and 92.16%, respectively. CONCLUSION: WSS at plaque surface combined with hypertension, diabetes, Hcy, blood glucose, plaque properties, and stenosis rate can significantly improve the accuracy of predicting TIA.

A cytosine methyltransferase ortholog dmtA is involved in the sensitivity of Aspergillus flavus to environmental stresses.

DNA methylation is an important epigenetic modification that depends on DNA methyltransferases (DMT). However, the filamentous fungus Aspergillus flavus has no detectable methylation, and role of a DMT homologue, DmtA, is undefined. Here we describe the role of the dmtA gene responding to changes in the environment by comparing knockout, point mutation, over-expression and wild type strains. Deletion of dmtA differentially affected conidia development in a media-dependent fashion, which suggests that dmtA plays an important role in conidiation. Furthermore, ΔdmtA strains lost the capacity to form the resistant structure, sclerotia, and alleviated sensitivity to several stress conditions, such as high osmotic pressure, hypoxia, low water activity and a high calcium concentration. We also noticed that deletion of dmtA and mutation C377S in DmtA negatively affected aflatoxin production and down regulated the expression of some early (fas-1, pksA, nor-1), middle and late (nor-A, ver-1, avnA, omtB) genes in the aflatoxin biosynthetic cluster. Finally, we found that all tested strains showed a similar phenotype when treated with 5-azacytidine. Our results indicate that the dmtA gene is important in regulation of aflatoxin biosynthesis and for A. flavus to adapt to stressful environments and for survival, although it may hold no apparent function in DNA methylation.

Fractionation of rapeseed straw by hydrothermal/dilute acid pretreatment combined with alkali post-treatment for improving its enzymatic hydrolysis.

The aim of the research was to evaluate the effect of combined treatments on fermentable sugar production from rapeseed straw. An optimum condition was found to be the combination of hydrothermal pretreatment at 180°C for 45min and post-treatment by 2% NaOH at 100°C for 2h, which was based on the quantity of monosaccharides released during enzymatic hydrolysis. As compared with the raw material without treatment, the combination of hydrothermal pretreatment and alkali post-treatment resulted in a significant increase of the saccharification rate by 5.9times. This process potentially turned rapeseed straw into value added products in accordance with the biorefinery concept.

SNX-2112, an Hsp90 inhibitor, induces apoptosis and autophagy via degradation of Hsp90 client proteins in human melanoma A-375 cells.

SNX-2112 is an Hsp90 inhibitor which is currently undergoing multiple phase 1 clinical trials; however, its mechanism of action needs to be further elaborated. Here we investigated the effects of SNX-2112 in A-375 cells. SNX-2112 induced the degradation of multiple Hsp90 client proteins, activated both the mitochondrial-mediated and death receptor-mediated apoptotic pathways, downregulated Bcl-2 and Bcl-xL, upregulated Bid, cleaved caspase-9, caspase-7, caspase-3 and PARP, and activated caspase-8. The general caspase inhibitor, z-VAD-fmk, did not completely abolish SNX-2112-induced cell death. SNX-2112 induced autophagy in a time- and dose-dependent manner via Akt/mTOR/p70S6K inhibition. SNX-2112 induces significant apoptosis and autophagy in human melanoma A-375 cells, and may be an effective targeted therapy agent.

[Monoclonal antibody preparation and identification of vascular endothelial growth factor 165 expressed in vitro].

AIM: To prepare a monoclonal antibody against human vascular endothelial growth factor (VEGF165), for further study the VEGF165 in the tumorigenesis, tumor cell migration and the tumor cells escape from the immune response. METHODS: VEGF165 gene was cloned from the human umbilical vein endothelial cells (HUVEC) by RT-PCR, and then cloned into the pGEX-6P1, constructed the prokaryotic expression of pGEX-6P1-VEGF165. The fusion -protein of VEGF165 was expressed in E.coli (BL21) induced by the 1.0 mmol/L IPTG at 37DegreesCelsius after 4 h. The fusion-protein was purified by the MicroSpin GST purification kit for immunized the BALB/c mouse. The monoclonal antibodies (mAbs) against the VEGF165 were prepared by hybridoma technique, and ELISA and Western blot identified their immunoglobulin subclass and specificity. And we used the inhibition the embryo angiogenesis assay, inhibition the HUVEC migration assay and inhibition the HUVEC tubule information assay to study the bioactivity of the mAbs of VEGF165. RESULTS: The sequence of the VEGF165 is agreed to the GenBank, and we obtained five species VEGF165 mAbs, and the titer of the antibody is high, and we named, they are 5A6, 3F5, 6H3, 7D10 and 7A10. Our study showed that the 5A6, 3F5, 6H3, 7D10 were classified to IgG2a, 7A10 was classified to IgG2b, and the light chain is k.Meanwhile the purified mAbs inhibited formation of chicken embryo blood vessels, and inhibited tubule formation of the HUVEC and inhibited migration of the HUVEC. CONCLUSION: mAbs against human VEGF165 have the effective bioactivity, which would play a significant role for further study the mechanism of VEGF165.

[An efficient approach to gene discovery--normalization of cDNA library by reassociation].

The cDNA library normalized by reassociation is a newly-developed, effective platform for EST acquisition and gene discovery. This paper presents the principle, procedure, comparison, deficiencies, application and future of the technique of the normalization.