High-efficient separation of deoxyribonucleic acid from pathogenic bacteria by hedgehog-inspired magnetic nanoparticles microextraction.

Efficient separation of deoxyribonucleic acid (DNA) through magnetic nanoparticles (MN) is a widely used biotechnology. Hedgehog-inspired MNs (HMN) possess a high-surface-area due to the distinct burr-like structure of hedgehog, but there is no report about the usage of HMN for DNA extraction. Herein, to improve the selection of MN and illustrate the performance of HMN for DNA separation, HMN and silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2) were fabricated and compared for the high-efficient separation of pathogenic bacteria of DNA. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are typical Gram-negative and Gram-positive bacteria and are selected as model pathogenic bacteria. To enhance the extraction efficiency of two kinds of MNs, various parameters, including pretreatment, lysis, binding and elution conditions, have been optimized in detail. In most separation experiments, the DNA yield of HMN was higher than that of Fe3O4@SiO2. Therefore, a HMN-based magnetic solid-phase microextraction (MSPE) and quantitative real-time PCR (qPCR) were integrated and used to detect pathogenic bacteria in real samples. Interestingly, the HMN-based MSPE combined qPCR strategy exhibited high sensitivity with a limit of detection of 2.0 × 101 CFU mL-1 for E. coli and 4.0 × 101 CFU mL-1 for S. aureus in orange juice, and 2.8 × 102 CFU mL-1 for E. coli and 1.1 × 102 CFU mL-1 for S. aureus in milk, respectively. The performance of the proposed strategy was significantly better than that of commercial kit. This work could prove that the novel HMN could be applicable for the efficient separation of DNA from complex biological samples.

The changes of Lp-PLA2 in patients with gestational diabetes and its clinical significance.

ABSTRACT: Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy and associated with adverse pregnancy outcomes. The aim of this study was to investigate the changes of lipoprotein-associated phospholipaseA2 (Lp-PLA2) level and its correlation with biochemical indexes in patients with GDM.This observational cross-sectional study was performed among 52 GDM and 48 healthy pregnant women. Automatic biochemical analyzer was employed to test the biochemical indexes, including fasting plasma glucose (FPG), Hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). The lipoprotein-associated phospholipaseA2 (Lp-PLA2) level was evaluated by enzyme-linked immunosorbent assay, and homeostatic model assessment for insulin resistance (HOMA-IR) was calculated.The levels of FPG, HbA1c, HOMA-IR, TG, TC and LDL-C were significantly increased while high-density lipoprotein cholesterol (HDL-C) level was significantly decreased in the GDM group when compared with those in the control group. Lp-PLA2 level in maternal blood in the GDM group was significantly higher than that in the control group (199.125 ±â€Š23.494 vs165.825 ±â€Š15.576 ng/mL, P < .05) and logistic regression analysis further confirmed the association of Lp-PLA2 levels with GDM. Furthermore, Lp-PLA2 positively correlated with HOMA-IR, TC, and LDL-C.Our results confirmed the association of Lp-PLA2 with GDM. This broadens our knowledge on the pathophysiology of GDM and provides insights into the development of new targets for the prevention and treatment of GDM.

[Effect of arginine vasopressin on membrane potential of dorsal root ganglion neurons in rats].

The effect of arginine vasopressin (AVP) on membrane potential of neurons from dorsal root ganglion (DRG) was examined in the rat by means of intracellular recording technique. The results showed that (1) AVP induced hyperpolarization in the membrane of most DRG neurons. (2) The membrane conductance of the DRG neurons increased by 19.32% following application of AVP (p<0.05). (3) Perfusion with balance sodium solution (BSS) containing Cd(2+) (blocker of Ca(2+) channel) instead of Na+ failed to affect the AVP-induced membrane hyperpolarization of the DRG neurons (p> 0.05). After perfusion with BSS containing tetraethylammonium (TEA), however, the extent of AVP-induced hyperpolarization was reduced (p<0.05). (4) The AVP-induced hyperpolarization of the neurons was blocked by the antagonist of AVP V(1) receptors. The results demonstrate that AVP induces hyperpolarization of most DRG neurons, which might be caused by K(+) outflow mediated by AVP V(1) receptors in the membrane of the neurons.