Simultaneous detection of four pesticides in agricultural products by a modified QuEChERS method and LC-MS/MS.

A modified QuEChERS pretreatment method and LC-MS/MS technique were performed to simultaneously determine four pesticide (Hexachlorophene, Dinex, Dinosam, Dinoterb) residues in agricultural products. Through the optimization of LC-MS/MS detection parameters in SIM mode, the optimal instrument conditions are obtained. The modified QuEChERS method was used to pretreat the samples. Solid phase extractants PSA, C18 and GCB were used for sample purification. The research results showed that the correlation coefficients of the four pesticides were all greater than 0.991, which had a good linear relationship. The limits of quantitation (LOQ) of the four pesticides were 0.05-0.56 µg/kg. The recoveries were 70.51-113.20% with relative standard deviations (RSDS) of 1.6-11.2%. The developed method can provide reliable data support for the subsequent simultaneous detection of these four pesticides.

Multiresidue Pesticide Analysis in Tea Using GC-MS/MS to Determine 12 Pesticide Residues (GB 2763-2021).

Pesticides are widely used on tea plants, and pesticide residues are of significant concern to consumers. The National Food Safety Standard Maximum Residue Limits for Pesticides in Food (GB 2763-2021) was recently amended. However, detection methods for pesticides newly added to the list of residues in beverages have not yet been established. For that reason, this study developed a solid-phase extraction (SPE) and gas chromatography-tandem mass spectrometry (GC-MS/MS) method for determining the residues of 12 pesticides, including four newly added, in black and green tea. Sample preparation processes (sample extraction, SPE clean-up, elution solvent, and elution volume) were optimized to monitor these residues reliably. Multiple reaction monitoring (MRM) was used for GC-MS/MS electron impact (EI) mode determination. Finally, satisfactory recoveries (70.7-113.0% for green tea and 72.0-99.1% for black tea) were achieved at three concentrations (10 µg/kg, 20 µg/kg, and 100 µg/kg). The LOQs were 0.04-8.69 µg/kg, and the LODs were 0.01-3.14 µg/kg. This study provides a reliable and sensitive workflow for determining 12 pesticide residues in tea, filling a gap in the newly revised National Standards.

Establishment of an LC-MS/MS Method for the Determination of 45 Pesticide Residues in Fruits and Vegetables from Fujian, China.

Pesticide residues in food have become an important factor seriously threatening human health. Therefore, this study was conducted to determine the pesticide residues in fruits and vegetables commonly found in Fujian, China, with the aim of constructing a simple and rapid method for pesticide residue monitoring. We collected 5607 samples from local markets and analyzed them for the presence of 45 pesticide residues. A fast, easy, inexpensive, effective, robust, and safe (QuEChERS) multi-residue extraction method followed by liquid chromatography equipped with triple-quadrupole mass spectrometry (LC-MS/MS) was successfully established. This 12-min-long analytical method detects and quantifies pesticide residues with acceptable validation performance parameters in terms of sensitivity, selectivity, linearity, the limit of quantification, accuracy, and precision. The linear range of the calibration curves ranged from 5 to 200 mg/L, the limits of detection for all pesticides ranged from 0.02 to 1.90 µg/kg, and the limits of quantification for the pesticides were 10 µg/kg. The recovery rates for the three levels of fortification ranged from 72.0% to 118.0%, with precision values (expressed as RSD%) less than 20% for all of the investigated analytes. The results showed that 726 (12.95%) samples were contaminated with pesticide residues, 94 (1.68%) samples exceeded the maximum residue limit (MRL) of the national standard (GB 2763-2021, China), 632 (11.23%) samples were contaminated with residues below the MRL, and 4881 (87.05%) samples were pesticide residue-free. In addition, the highest number of multiple pesticide residues was observed in bananas and peppers, which were contaminated with acetamiprid, imidacloprid, pyraclostrobin, and thiacloprid.

Simultaneous determination of boscalid and fludioxonil in grape and soil under field conditions by gas chromatography/tandem triple quadrupole mass spectrometry.

A gas chromatography-tandem mass spectrometry method was developed and validated to simultaneously determine boscalid and fludioxonil in grape and soil samples. These samples were extracted with 10 mL of acetonitrile and purified using a mixed primary secondary amine/octadecylsilane sorbent. The method showed good linearity (R2 > 0.99) in the calibration range 0.005-2 µg/mL for both pesticides. The limits of detection and quantification for the two analytes in grape and soil were 0.006 and 0.02 mg/kg, respectively. Fungicide recoveries in grape and soil were 81.18-92.11% for boscalid and 82.73-97.67% for fludioxonil with relative standard deviations of 1.31-10.31%. The established method was successfully applied to the residual analysis of boscalid and fludioxonil in real grape and soil samples. The terminal residue concentrations of boscalid and fludioxonil in grape samples collected from Anhui and Guizhou were <5 mg/kg (the maximum residue limit set by China) 7 days after the last application and 1 mg/kg (the maximum residue limit set by USA) 14 days after the last application. These results could provide guidance for the proper and safe use of boscalid and fludioxonil in grape and help the Chinese government to establish an MRL for fludioxonil in grape.

Simultaneous determination of residues of metalaxyl, cyazofamid and a cyazofamid metabolite in tobacco leaves and soil by liquid chromatography with tandem mass spectrometry.

A simple method was developed and validated for the simultaneous determination of metalaxyl, cyazofamid and the cyazofamid metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) by liquid chromatography with tandem mass spectrometry. The three target compounds were extracted from tobacco and soil with acetonitrile containing 0.1% acetic acid, and the extracts were purified using octadecylsilane. The proposed method showed satisfactory linearity (R2 ≥ 0.9985) for the target compounds. The limits of detection for metalaxyl, cyazofamid and CCIM were 0.006, 0.06 and 0.06 mg/kg in soil and green tobacco leaves and 0.03, 0.3 and 0.3 mg/kg in cured tobacco leaves, respectively. The limits of quantification for metalaxyl, cyazofamid and CCIM were 0.02, 0.2 and 0.2 mg/kg in soil and green tobacco leaves and 0.1, 1 and 1 mg/kg in cured tobacco leaves, respectively. The average recoveries from soil and tobacco were 72.91-98.40% for metalaxyl, 76.73-105.80% for cyazofamid and 74.48-106.45% for CCIM. The relative standard deviation range was 1.23-6.99%. The developed method was successfully applied to analysis of residues of metalaxyl, cyazofamid and CCIM in real soil and tobacco samples. The results indicated that the established method could meet the requirement for the analysis of trace amounts of all three analytes in soil and tobacco.

Simultaneous determination and method validation of difenoconazole, propiconazole and pyraclostrobin in pepper and soil by LC-MS/MS in field trial samples from three provinces, China.

A liquid chromatography-electrospray ionization tandem mass spectrometry method was developed for simple and accurate detection of the fungicides difenoconazole, propiconazole and pyraclostrobin in peppers and soil. Three fungicides residues were extracted from samples by acetonitrile and cleaned up by dispersive solid-phase extraction before instrumental analysis. The accuracy and precision of the method were evaluated by conducting an intra- and inter-day recovery experiment. The limits of quantification and detection of difenoconazole, propiconazole and pyraclostrobin in pepper and soil were 0.005 and 0.0015 mg/kg, respectively. The recoveries were investigated by spiking pepper and soil at three levels, and were found to be in the ranges 79.62-103.15% for difenoconazole, 85.94-103.35% for propiconazole and 80.14-97.69% for pyraclostrobin, with relative standard deviations <6.5%. Field experiments were conducted in three locations in China. The half-lives of difenoconazole, propiconazole and pyraclostrobin were 5.3-11.5 days in peppers and 6.1-32.5 days in soil. At harvest, pepper samples were found to contain difenoconazole, propiconazole and pyraclostrobin well below the maximum residue limits of European Union at the interval of 21 days after last application following the recommended dosage.

Stereoselective determination of dufulin in watermelon under field conditions using chiral ultra high performance liquid chromatography with high-resolution mass spectrometry.

An effective and sensitive chiral analytical method was established to investigate the stereoselective dissipation of rac-dufulin in watermelon using ultra high performance liquid chromatography with a superchiral S-OD chiral column (4.6 × 150 mm i.d., 5 µm) coupled with high-resolution mass spectrometry. To optimize the pretreatment method for detecting rac-dufulin in the three matrixes, different extraction solvents, extractant volumes, extraction times, and absorbents were investigated to improve extraction efficiency. Moreover, analysis of variance was used to perform method validation for determination of the two dufulin enantiomers in the three matrixes. Using the optimized method, good linearity was obtained (determination coefficient > 0.999). The limits of detection and quantification of the two dufulin enantiomers in soil, watermelon, and pulp were 0.15 and 0.5 µg/kg, respectively. The average recoveries of the two enantiomers in the three matrixes at four spiked levels ranged from 75.0 to 107.8%, with intra- and inter-day relative standard deviations of 0.4-10.4%. In field trials, the R enantiomer was preferentially dissipated in watermelon. These method validation results confirmed that the developed method was convenient and reliable for the stereoselective determination of enantiomers of rac-dufulin in watermelon.

Risk assessment and monitoring of dinotefuran and its metabolites for Chinese consumption of apples.

Residues of dinotefuran and its metabolites, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN), in apple were investigated using a "QuEChERS" (quick, easy, cheap, effective, rugged, safe) pretreatment and liquid chromatography-tandem mass spectrometry. Limits of detection (LODs) and quantification (LOQs) of dinotefuran, UF, and DN in apples were 0.011-0.960 and 0.037-3.200 µg/kg, respectively. The average recoveries of dinotefuran, UF, and DN in apple ranged from 70.0 to 83.6% with relative standard deviations less than 13%. A formulation of 20% water-dispersible dinotefuran granules was sprayed at 1-1.5-fold the recommended dose 3-4 times on apple trees. Total terminal residues of dinotefuran in apple were less than 2 mg/kg, which is the maximum residue limit (MRL) set by Japan. When following the recommended application guidelines, dinotefuran is unlikely to present significant health concerns to the Chinese population because the risk quotient (RQ) is less than 100%. This work could provide guidance for the safe use of dinotefuran and serve as a reference for the establishment of a maximum residue limit of dinotefuran in apple in China.

Low mir-372 expression correlates with poor prognosis and tumor metastasis in hepatocellular carcinoma.

BACKGROUND: Recent studies have shown that miR-372 plays important roles in hepatocellular carcinoma (HCC) progression. However, results have been conflicting regarding its expression levels and role in HCC. METHODS: RT-PCR and in situ hybridization was used to evaluate miR-372 expression in HCC tissues and cell lines. The methylation status of neighboring CpG islands upstream of the miR-372 promoter was analyzed by methylation-specific PCR (MSP). Transfection of miR-372 mimic into HCC cell lines was used to evaluate cellular proliferation and invasion. Prognostic significance was analyzed by the Kaplan-Meier survival method and Cox regression. RESULTS: miR-372 was expressed at lower levels in HCC tissues compared with controls and was related to tumor metastasis and poor prognosis. Hypermethylation of miR-372 was detected in HCC cell lines and tissues, and miR-372 expression was restored upon 5-aza-dCyd treatment. Upregulated expression by mir-372 mimic transfection inhibited proliferation and invasion capacity in HCC cells. CONCLUSIONS: miR-372 may play an important role in hepatic carcinogenesis and may serve as a new target or method to detect and treat HCC in the future.

Managing abdominal cocoon syndrome complicated by intestinal necrosis and unexpected amelioration of depression after surgery: a case report.

BACKGROUND: Abdominal cocoon is a very uncommon yet dangerous cause of intestinal obstruction. CASE PRESENTATION: We present a case of a 62-year-old Asian male patient with a history of depression who exhibited an idiopathic abdominal cocoon complicated by necrosis. Upon laparotomy investigation, nearly the entire small intestine was enveloped in a thick membrane resembling a cocoon, and it was discovered that he lacked a greater omentum. The patient recovered well and was discharged on an oral diet on the 20th day following surgery. During the 3-month follow-up, the patient was asymptomatic, even gaining 10 kg in weight, and noted that his depression had improved. CONCLUSIONS: Small bowel obstruction presents with nonspecific symptoms, posing challenges in differential diagnosis. Contrast-enhanced computed tomography is recommended since it facilitates precise preoperative assessment, optimizing surgical planning and reducing postoperative complications. Remarkably, cessation of antidepressant medication post-surgery hints at a potential correlation between omental deficit, gut microbiota alterations, and depressive symptoms.

Identification of Novel Imatinib-Resistant Genes in Gastrointestinal Stromal Tumors.

Gastrointestinal stromal tumors (GISTs) are common ICC precursor sarcomas, which are considered to be a potential malignant mesenchymal tumor driven by specific KIT or PDGFRA signals in the gastrointestinal tract. The standard treatment for GIST without metastasis is surgical resection. GIST with metastasis is usually treated with tyrosine kinase inhibitors (TKIs) only but cannot be cured. The TKI imatinib is the main drug of GIST drug therapy. In adjuvant therapy, the duration of imatinib adjuvant therapy is 3 years. It has been proved that imatinib can improve the overall survival time (OS). However, many GIST patients develop drug resistance due to the long-term use of imatinib. We were forced to look for new strategies to treat GIST. The purpose of the current academic work is to study the drug-resistant genes of imatinib and their potential mechanisms. A total of 897 differentially expressed genes (DEGs) were found between imatinib-sensitive cell line GIST882 and imatinib-resistant cell line GIST430 by RNA sequencing (RNA-seq). After analyzing the DEGs, 10 top genes were selected (NDN, FABP4, COL4A1, COLEC11, MEG3, EPHA3, EDN3, LMO3, RGS4, and CRISP2). These genes were analyzed by RT-PCR, and it was confirmed that the expression trend of FABP4, COL4A1, and RGS4 in different imatinib-resistant cell lines was in accord with the GEO database. It is suggested that these genes may play a potential role in the clinical diagnosis and treatment of imatinib resistance in GIST.

Laparoscopic and Endoscopic Cooperative Dissection for Small Gastric Gastrointestinal Stromal Tumor without Causing Injury to the Mucosa.

OBJECTIVE: To investigate the feasibility of laparoscopic and endoscopic cooperative dissection (LECD) for small gastric gastrointestinal stromal tumors (GISTs) without causing injury to the mucosa, compared with ESD surgery which is widely used now. METHODS: A total of 25 patients with small gastric GISTs who underwent LECD and 20 patients with small gastric GISTs who underwent ESD between October 2014 and June 2016 were included in this study. All patients underwent curative resection for pathologically diagnosed small gastric GISTs. Patients' clinical data were retrospectively analyzed. RESULTS: In LECD group, the operation was successfully performed in all patients. However, in the ESD group, three patients were transferred to laparoscopic surgery due to intraoperative massive bleeding or intraoperative perforation. No additional targeted chemotherapy drugs for interstitial tumors were prescribed in two groups. There was no difference in the complete tumor capsule rate (100% vs. 90%, p = 0.11), operation time (80.76 ± 13.86 ml vs. 84.05 ± 15.33 ml, p = 0.45), major intraoperative bleeding (0 vs. 5%, p = 0.26), postoperative bleeding (0 vs. 10%, p = 0.11), and postoperative infection (0 vs. 10%, p = 0.11) between the two groups. Compared to ESD (endoscopic submucosal dissection), LECS patients had shorter postoperative indwelling gastric tube (1.04 ± 0.98 d vs. 2.85 ± 0.24 d, p < 0.01), earlier postoperative eating (1.96 ± 0.98 d vs. 3.50 ± 1.15 d, p < 0.01), shorter average postoperative hospital stay (3.44 ± 1.00 d vs. 7.85 ± 1.18 d, p < 0.01), smaller perforation rate (0 vs. 25%, p < 0.05), and fewer surgical supplies. No recurrence or metastasis cases were found between the two groups during the follow-up period, and there were no cases of death due to gastric GISTs. CONCLUSION: LECD is a novel surgery for small gastric gastrointestinal stromal tumors that leads to satisfactory short-term outcomes and meets the idea of minimally invasive surgery and rapid recovery; compared with ESD, LECD surgery has some advantages in clinical practice. However, further follow-up is needed to confirm.

Determination, residue analysis, risk assessment and processing factor of pymetrozine and its metabolites in Chinese kale under field conditions.

A simple determination method for pymetrozine and its metabolites in Chinese kale was developed using liquid chromatography with tandem mass spectrometry. The method had good linearity (R2 > 0.99), accuracy (recoveries of 73.2-94.1%) and precision (relative standard deviation of 2.5-9.8%). Field results showed that half-lives of pymetrozine were 3.0-4.1 d in Chinese kale, and terminal residue concentrations were all below the United States Environmental Protection Agency's maximum residue limit (250 µg/kg) at harvest. Owing to risk quotient <100%, pymetrozine is unlikely to give rise to vital health concerns to humans following the recommended application guidelines. Moreover, effects of home processing on pymetrozine residues in Chinese kale were monitored. The processing factor values of four processes were between 0.19 and 0.60, which indicated that the used processes could remove pymetrozine residues from Chinese kale, especially pickling after washing process. The data could provide guidance to safe and reasonable use of pymetrozine and help Chinese governments establish a maximum residue limit for pymetrozine in Chinese kale.

Laparoscopic Endoscopic Cooperative Surgery for Gastrointestinal Stromal Tumors.

With the development of laparoscopy and digestive endoscopy, multiple laparoscopic and endoscopic cooperative surgeries (LECSs) for gastrointestinal stromal tumors have recently been developed. Classic LECS has been confirmed as a feasible and safe treatment procedure for gastrointestinal stromal tumors with regard to both short-term surgical and long-term oncological outcomes; however, classic LECS has the potential risk of gastric contents or tumor cells spilling into the abdominal cavity because the gastric wall has to be opened during the procedure. Various modified LECS techniques have aimed at further minimizing invasiveness, such as the full-thickness resection method using the nonexposure technique (combination of laparoscopic and endoscopic approaches to neoplasia with a nonexposure technique), nonexposed endoscopic wall-inversion surgery, and closed LECS. This review describes and summarizes the current LECS for gastrointestinal tumor.

MicroRNA-655-3p functions as a tumor suppressor by regulating ADAM10 and ß-catenin pathway in Hepatocellular Carcinoma.

BACKGROUND: Increasing evidence suggests that microRNAs (miRNAs) play critical roles in malignant transformation, tumor progression and metastasis. Aberrant miR-655-3p expression has been associated with several cancers. However, the role and underlying mechanism of miR-655-3p in the development of hepatocellular carcinoma (HCC) remains unclear. METHODS: MiR-655-3p expression was detected by quantitative RT-PCR (qRT-PCR) in human HCC tissues and cell lines. Cell proliferation was investigated using MTT and colony formation assays, and cell migration and invasion abilities were evaluated by transwell assay. ADAM10 protein expression was detected by immunohistochemical assay. The target gene and downstream of miR-655-3p were determined by qRT-PCR, western blot and dual-luciferase reporter assays. RESULTS: miR-655-3p was significantly down-regulated in HCC tissues and HCC cell lines. Low miR-655-3p expression was negatively related to tumor size, portal vein tumor thrombosis (PVTT) status, TNM stage and metastasis status. In addition, miR-655-3p overexpression and depletion decreased and increased HCC cell proliferation, migration and invasion, respectively. Moreover, ADAM10 was identified as a direct target of miR-655-3p, and miR-655-3p down-regulated E-cadherin protein level and inhibits ß-catenin pathway by mediating ADAM10. CONCLUSIONS: MiR-655-3p might functions as a tumor suppressor by directly targeting ADAM10 and indirectly regulating ß-catenin pathway in the development of progression of HCC. It may be a novel therapeutic candidate target to in HCC treatment.