Multi-Residue Analysis of Pesticide Residues in Crude Pollens by UPLC-MS/MS.

A multi-residue method for the determination of 54 pesticide residues in pollens has been developed and validated. The proposed method was applied to the analysis of 48 crude pollen samples collected from eight provinces of China. The recovery of analytes ranged from 60% to 136% with relative standard deviations (RSDs) below 30%. Of the 54 targeted compounds, 19 pesticides were detected. The major detection rates of each compound were 77.1% for carbendazim, 58.3% for fenpropathrin, 56.3% for chlorpyrifos, 50.0% for fluvalinate, 31.3% for chlorbenzuron, and 29.2% for triadimefon in crude pollen samples. The maximum values of each pesticide were 4516 ng/g for carbendazim, 162.8 ng/g for fenpropathrin, 176.6 ng/g for chlorpyrifos, 316.2 ng/g for fluvalinate, 437.2 ng/g for chlorbenzuron, 79.00 ng/g for triadimefon, and so on. This study provides basis for the research on the risks to honeybee health.

Effect of electroacupuncture on ventricular structure and function in rats with myocardial ischemia-reperfusion injury. / ç”µé’ˆå¯¹å¿ƒè‚Œç¼ºè¡€å†çŒæ³¨æŸä¼¤å¤§é¼ å¿ƒå®¤ç»“æž„å’ŒåŠŸèƒ½çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) on changes of ventricular structure and function in rats with myocardial ischemia-reperfusion injury (MIRI), so as to explore its potential mechanisms underlying improvement of ventricular remodeling after MIRI. METHODS: Forty male SD rats were randomly divided into 4 groups：sham operation group, model group, EA group and medication (sacubactril valsartan, LCZ696) group, with 10 rats in each group. The MIRI model was established by ligation of the left anterior descending coronary artery and reperfusion. EA (2 Hz/100 Hz, 2 mA) was applied to bilateral "Neiguan" (PC6) for 20 min, once every other day for 21 d. Rats of the medication group received gavage of LCZ696 (60 mg·kg-1·d-1). After the intervention, echocardiography was used to detect the ejection fraction (EF) and fractional shortening (FS) of the left ventricle, and the contents of serum tumor necrosis factor-α(TNF-α), vascular cell adhesion molecule-1(VCAM-1) and intercellular cell adhesion molecule-1(ICAM-1) were assayed by enzyme-linked immunosorbent assay. The pathological changes of myocardial tissue were observed after HE staining. The Masson staining was used to evaluate the myocardial collagen deposition and myocardial fibrosis. The mRNA expression levels of collagen Ⅰ and Ⅲ and connective tissue growth factor (CTGF) in the myocardial tissue were detected by quantitative real-time PCR, and the expression levels of IL-1ß and IL-18 were detected by Western blot. RESULTS: In contrast to the sham operation group, the EF and FS levels of the left ventricle were ob-viously decreased (P<0.001), while the contents of serum TNF-α, VCAM-1 and ICAM-1, the proportion of myocardial fibrosis area, the mRNA expression levels of myocardial collagen Ⅰ, collagen Ⅲ and CTGF, the expression levels of IL-1ß and IL-18 were significantly increased (P<0.001, P<0.000 1, P<0.05, P<0.01) in the model group. Compared with the model group, the EF and FS levels were remarkably increased (P<0.01), whereas the contents of serum TNF-α, VCAM-1 and ICAM-1, the proportion of myocardial fibrosis area, the mRNA expression levels of myocardial collagen Ⅰ, collagen Ⅲ and CTGF, and the expression levels of IL-1ß and IL-18 were significantly down-regulated (P<0.001, P<0.01, P<0.05) in both the medication and EA groups. No significant differences were found between the EA and medication groups in all the indexes mentioned above. CONCLUSIONS: EA can improve the left-ventricular fibrosis and function, delay or reverse ventricular remodeling in MIRI rats, which may be related to its functions in down-regulating myocardial inflammatory response and mRNA expression levels of myocardial collagen Ⅰ, collagen Ⅲ and CTGF.

Electroacupuncture preconditioning protects against myocardial ischemia-reperfusion injury by modulating dynamic inflammatory response.

Background: The protective effects of electroacupuncture (EA) preconditioning against myocardial ischemia-reperfusion injury (MIRI) have been reported. However, the underlying mechanism remains unclear. Recent research has indicated that the dynamic inflammatory response following MIRI plays an essential role in the progression of myocardial injury. This study aimed to investigate the myocardial protective effects of EA preconditioning on MIRI in rats and to explore the relevant mechanism from the perspective of dynamic inflammatory response. Methods: A MIRI model was employed, and the rats were subjected to EA on Neiguan for four days prior to modeling. The myocardial protective effect of EA preconditioning was evaluated by echocardiography, Evans blue and triphenyltetrazolium chloride staining. Real-time polymerase chain reaction, Western blot, hematoxylin & eosin staining, and immunohistochemistry were utilized to detect the content of mitochondrial DNA, NOD receptor family protein 3 (NLRP3) inflammasome activation, neutrophil recruitment and macrophage infiltration in blood samples and myocardium below the ligation. Results: We found that EA preconditioning could accelerate the recovery of left ventricle function after MIRI and reduce the myocardial infarction area, thereby protecting the myocardium against MIRI. Furthermore, EA preconditioning was observed to ameliorate mitochondrial impairment, reduce the level of plasma mitochondrial DNA, modulate NLRP3 inflammasome activation, attenuate neutrophil infiltration, and promote the polarization of M1 macrophages towards M2 macrophages in the myocardium after MIRI. Conclusion: EA preconditioning could reduce plasma mtDNA, suppress overactivation of the NLRP3 inflammasome, facilitate the transition from the acute pro-inflammatory phase to the anti-inflammatory reparative phase after MIRI, and ultimately confer cardioprotective benefits.

Characterization of PGRP-S1 from the oriental armyworm, Mythimna separata.

Peptidoglycan is the key component forming the backbone of bacterial cell wall. It can be recognized by a group of pattern recognition receptors, known as peptidoglycan recognition proteins (PGRPs) in insects and higher animals. PGRPs may serve as immune receptors or N-acetylmuramoyl-L-alanine amidases (EC 3.5.1.28). Here, we report the characterization of a short PGRP, PGRP-S1, from the oriental armyworm, Mythimna separata. MsePGRP-S1 cDNA encodes a protein of 197 amino acids (aa) with a PGRP domain of about 150 aa. MsePGRP-S1 was expressed in several tissues of naïve larvae, including hemocytes, midgut, fat body and epidermis. Bacterial challenges caused variable changes in different tissues at the mRNA level. The recombinant protein bound strongly to Staphylococcus aureus and purified peptidoglycans from Staphylococcus aureus and Bacillus subtilis. It can inhibit the growth of gram-negative and gram-positive bacteria by disrupting bacterial surface. It can degrade peptidoglycans from Escherichia coli and Staphylococcus aureus. Taken together, these data demonstrate that M. separata PGRP-S1 is involved in defending against bacteria.