Plant hormones have a prominent place in the plant immune and defense mechanism. To gain more information about the plant hormone pathways involved in rice defense against nematodes, here, we studied the roles of three core hormones, namely, salicylic acid (SA), jasmonate (JA), and ethylene (ET) in rice defense to Aphelenchoides besseyi by using the susceptible variety, Nipponbare as well as the resistant variety Tetep. The data showed that Tetep exhibited pre- and post-invasion with suppression of nematode infection, development, and reproduction. The quantitative real-time (qRT)-PCR analysis of plant hormone marker genes in the two cultivars clearly revealed that all the SA-related genes were downregulated in susceptible Nipponbare plants but were significantly upregulated in resistant Tetep plants at the flowering stage. The exogenous application of the SA analog, benzo-1,2,3-thiadiazole-7-carbothioic acid S-methyl ester (BTH), methyl jasmonate (MeJA), and ethephon did induce rice resistance to A. besseyi, and the rice plants treated by hormone inhibitors increased susceptibility to A. besseyi. Similarly, corresponding transgenic biosynthesis or signaling mutants of those hormones also showed an increased susceptibility. Collectively, these results suggest that SA, JA, and ET play important defense roles in rice against A. besseyi.

Pesticide residue analysis plays an important role in the quality control of Chinese materia medica. This paper reports the development and validation of an analytical method for the quantitative determination of the residues of 39 pesticides in 12 different matrices of Chinese materia medica. Sample preparation utilized the QuEChERS method with acetonitrile:1% aqueous acetic acid (9:1, v/v) as extraction solvent followed by sample clean-up by dispersive solid phase extraction using primary secondary amine sorbent and graphitized carbon black. Extracts were then analysed by gas chromatography coupled with electron impact mass spectrometry in the selected ion monitoring mode. Limit of detection (LOD) and limit of quantitation (LOQ) values were in the ranges 0.5–50ng/g and 1–100ng/g, respectively. The recoveries of the 39 pesticides were in the range 75–112% with precision (as relative standard deviation, RSD) <15%. The results show that the modified QuEChERS method allows rapid and sensitive analysis of multiple pesticide residues in Chinese materia medica

Most melanomas identified in the stomach are metastatic; primary gastric melanoma (PGM) is extremely rare, and the relevant studies are relatively scarce. PGM may be incorrectly diagnosed as other gastric malignant tumor types. We describe a rare case of PGM confirmed through long-term clinical observation and pathological diagnosis. A 67-year-old woman presented to our hospital with recurrent chest tightness and chest pain. Digital gastrointestinal radiography revealed a circular shadow in the gastric cardia. Computed tomography (CT) revealed a heterogeneous tumor with uneven enhancement. Enlarged lymph nodes were noted in the lesser curvature of the stomach. On magnetic resonance imaging (MRI), T1- and T2-weighted imaging revealed hyperintensity in and hypointensity in the tumor, respectively, both of which increased substantially after uneven enhancement. Near total gastrectomy was performed, and the tumor was pathologically confirmed to be a gastric melanoma. Because no other possible primary site of malignant melanoma was suspected, a clinical diagnosis of PGM was made. The patient was followed for nearly 5 years, during which she received CT reexamination, but no recurrence or metastasis was observed. Certain imaging characteristics could be revealed in PGM. Imaging examination can be of great value in preoperative diagnosis, differential diagnosis, and follow-up of patients with PGM.