Rapid detection of aflatoxin B_1 in Chinese herbal medicines by indirect and direct competitive enzyme-linked immunosorbent assays: a comparative analysis / 中国中药杂志

The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.

Study on residues of heavy metals and harmful elements in Qingqiao and Laoqiao based on chemometrics / 中国中药杂志

Forsythiae Fructus is divided into Qingqiao and Laoqiao due to different harvesting periods. So far, the accumulation of heavy metals in the two types of Forsythiae Fructus has not been reported. In this study, the residual levels of copper(Cu), lead(Pb), chromium(Cr), arsenic(As), cadmium(Cd) and mercury(Hg) in 29 batches of Laoqiao and 60 batches of Qingqiao were determined by inductively coupled plasma mass spectrometry(ICP-MS). The samples were collected from Shanxi, Shaanxi, Henan, and Hebei Provinces. In addition, the diversity and correlation of harmful elements in Qingqiao and Laoqiao were analyzed by multivariate statistical method. Furthermore, principal component analysis(PCA) was used to analyze the harmful elements concentrations of Qingqiao and Laoqiao. The results showed that there was a significant difference on the residual levels of heavy metals and harmful elements between Qingqiao and Laoqiao. Among them, the content of Pb in Laoqiao is significantly higher than that in Qingqiao(P<0.01), while the content of Cu is significantly lower than that in Qingqiao. However, the difference in harmful elements among different producing areas of Forsythiae Fructus is not significant. PCA analysis showed that Qingqiao and Laoqiao were successfully grouped into two categories. This study suggests significant difference in the residual levels of heavy metals and harmful elements between Qingqiao and Laoqiao. Besides, Forsythiae Fructus has a certain enrichment of Pb in the fruit ripening stage(Laoqiao). This study provides a reference for the quality classification and safety of Forsythiae Fructus.

Preparation of highly sensitive monoclonal antibody against aflatoxin B_1 and its application in rapid detection of contamination in Ziziphi Spinosae Semen / 中国中药杂志

A highly sensitive monoclonal antibody against aflatoxin B_1(AFB_1) was prepared and an indirect competition enzyme-linked immunosorbent assay(ic-ELISA) was established based on the antibody which was used for high-throughput and rapid screening of AFB_1 contamination in Chinese herbal medicines to ensure the safety of medication. In this study, the structure of AFB_1 was modified by improved oxime method, and the carrier protein was coupled by EDC-NHS method to obtain the complete antigen of AFB_1, which was more convenient and environmental friendly. The Balb/c female mice were immunized using increasing the immunization dose and various ways of injection, and finally the AFB_1 monoclonal antibody was prepared. The AFB_1 monoclonal antibody belongs to IgG_(2 b) immunoglobulin by identifying its immunological characteristics, and its sensitivity(IC_(50)) can reach 0.15 μg·L~(-1), and the affi-nity is 2.81×10~8 L·mol~(-1). The cross-reaction rates of AFB_2, AFG_1, and AFG_2 were 35.07%, 8.75%, and 1.15%, respectively, and there was almost no cross-reactivity with other mycotoxins. Based on the high sensitivity and specificity of the antibody, an ic-ELISA method was established and applied to the determination of AFB_1 contamination in Ziziphi Spinosae Semen. According to the matrix matching standard curve, the linear concentration range for AFB_1 was 0.05-0.58 μg·L~(-1)(R~2=0.992), the recoveries were 88.00%-119.0%, and the detection limit was 1.69 μg·kg~(-1). The AFB_1 in 33 batches of Ziziphi Spinosae Semen samples was determined by ic-ELISA, and the contamination level was 3.62-206.58 μg·kg~(-1). The linear correlation coefficient between the detection results of ic-ELISA and UHPLC-MS/MS was 0.996, and there were no false positive and false negative cases. It indicates that the established ic-ELISA is accurate and reliable, and could provide a simple and effective technique for fast screening of AFB_1 contamination in Ziziphi Spinosae Semen, and also could be considered as the reference for the detection and monitoring of AFB_1 contamination in other Chinese herbal medicines.

Analysis of load resistance related body circumferences of students in teenager aviation schools / 军事医学

Objective To improve the load resistance ability of students in teenager aviation schools and carry out specialized training for the body situation and shape of students.Methods We selected students from 14 teenager aviation schools and measured their height,weight,and the circumferences of necks,chests,upper-arms,waists,hips,and thighs.We compared the data of these students from different areas and the parameters were analyzed statistically by correlation analysis.Results Totally 411 students from 6 southern schools and 403 students from northern schools were investigated.Their average body height,weight and body mass index (BMI) were (172.3 ± 4.39) cm,(62.7 ± 7.3) kg,and (21.1 ± 2.23)kg/m2 respectirely.Students from northern schools were taller and heavier than those from southern schools (P ＜ 0.05).There was no difference between students from northern and southern schools in BMI.Compared with the domestic average levels of height,weight and chest circumference of teenagers aged 14 to 17,students of teenager aviation schools were higher,but there was no difference in weight or chest circumference.The average circumferences of the chest,neck,left upper-arm,right upper-arm,waist,hip,left thigh and right thigh were (83.1 ± 5.06),(34.7 ±3.07),(25.2±2.33),(25.5 ±2.30),(73.4 ±6.73),(89.7 ±5.89),(50.1 ±5.22),and (50.2 ±5.27)cm,respectively.According to the data,students from northern schools had a bigger chest circumference and thigh circumference but a smaller neck circumference and upper-arms circumference than those from southern schools (P ＜ 0.05).The correlation coefficient between BMI and the circumferences of the chest,neck,left upper-arm,right upperarm,waist,hip,left thigh and right thigh was 0.2201,0.1066,0.2466,0.2499,0.2291,0.2149,0.2299,0.2264,respectively.All of them were statistically significant (P ＜ 0.0001).Conclusion Load resistance related parameters of students in teenager aviation schools are not different from the domestic levels,which points to the urgent need for load resistance ability training for these students.Some parameters vary between areas.BMI is positively related to those load resistance parameters.Based on regional variations and regularities found in this study,specialized load resistance ability training could be made more efficient.

Value of preoperative barium contrast examination for the diagnosis and operative planning in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the value of preoperative barium contrast examination for the diagnosis and operative planning in gastric cancer.</p><p><b>METHODS</b>Clinical data of 229 gastric cancer patients were analyzed retrospectively. Lesions were divided into three parts: the cardiac, the body, and the antrum. The diagnostic accuracy of localization and the extent of tumor between gastroscopy alone and gastroscopy plus barium contrast were compared with the results of surgical findings.</p><p><b>RESULTS</b>The diagnostic accuracy of localization and the extent of tumor for gastroscopy in the cardiac, the body and the antrum cancers were 100% and 78.4%, 94.6% and 86.5%, 98.1% and 84.6%, respectively, while for gastroscopy plus barium contrast were 100% and 84.8%, 100% and 91.9%, 99.0% and 90.4%, respectively. The diagnostic accuracy of both the localization and the extent of tumor were not significantly different between gastroscopy alone and gastroscopy plus barium contrast (P>0.05). Diagnostic accuracy of the length of esophagus infiltrated by cardiac cancer in gastroscopy was 60.6%, while in gastroscopy plus barium contrast was 90.9%, which was significantly different (P<0.05). Gastroscopy plus barium contrast was more accurate in predicting the possibility of thoracotomy in cardiac cancer infiltrating the lower esophagus.</p><p><b>CONCLUSIONS</b>It is necessary to perform preoperative barium contrast examination in cardiac cancer patients, so as to identify whether the lower esophagus is infiltrated and to measure the length of lesion, which can provide evidences for making a decision of thoracotomy. For gastric body and antrum cancer, there is no indication for barium contrast examination if gastroscopy findings are satisfied.</p>