Estudio cromosómico de 303 pérdidas gestacionales en México / Chromosome analysis of 303 pregnancy losses in Mexico

Resumen Antecedentes: Las alteraciones cromosómicas están presentes en 50 a 60 % de los abortos espontáneos y en 6 a 19 % de los mortinatos. Aunque se prefieren los microarreglos para estudiarlos, numerosos hospitales no pueden ofrecerlos. Objetivo: Presentar los resultados del estudio citogenético de 303 productos de la concepción (POC), 184 se obtuvieron de abortos espontáneos, 49 fueron mortinatos y en 17 no se identificó la de edad gestacional. Material y métodos: Se empleó cariotipo, hibridación in situ con fluorescencia, secuencias cortas repetidas en tándem y microarreglos, según el tipo de pérdida y la muestra disponible. Resultados: En 29 POC se encontró tejido materno, por lo que fueron eliminados de los análisis. En 250 (91.2 %)/274 casos se obtuvieron resultados informativos; la tasa de éxito del cariotipo fue de 80.7 %; la de los microarreglos de SNP, de 94.5 %; y la de la hibridación fluorescente in situ y la repetición corta en tándem, de 100 %. Se observaron anomalías citogenéticas en 57.6 % de los abortos espontáneos y en 24.5 % de los mortinatos; 94 % de las anomalías fueron numéricas y 6 %, submicroscópicas. Conclusiones: El cariotipo en conjunto con el estudio de secuencias cortas repetidas en tándem para descartar contaminación de células maternas es efectivo para estudiar abortos espontáneos; los microarreglos se recomiendan en los mortinatos.

Abstract Background: Chromosomal abnormalities are present in 50 to 60 % of miscarriages and in 6 to 19 % of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology. Objective: To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age. Material and methods: Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample. Results: In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7 %; that of single nucleotide polymorphism microarrays, 94.5 %; and that of fluorescence in situ hybridization and short tandem repeat, 100 %. Cytogenetic abnormalities were observed in 57.6 % of miscarriages and in 24.5 % of stillbirths; 94 % of total anomalies were numerical and 6 % were submicroscopic. Conclusions: Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.

Investigation of Effect of Different Processed Products of Atractylodes chinensis Rhizoma on Rats with Spleen Deficiency Based on Pharmacodynamics and Metabolomics / 中国实验方剂学杂志

ObjectiveTo clarify the differences in the efficacy and mechanism of different processed products of Atractylodes chinensis rhizoma by the pharmacodynamics and metabolomics studies of raw， bran-fried and rice water-processed products on rats with spleen deficiency. MethodSixty male SD rats were randomly divided into blank group， model group， raw product group（3.75 g·kg-1）， bran-fried product group（3.75 g·kg-1）， rice water-processed product group（3.75 g·kg-1） and Shenling Baizhusan group（6.7 g·kg-1）， with 10 rats in each group. The method of excessive fatigue+improper diet was used to establish a spleen deficiency model in rats. After the end of modeling， except for the blank and model groups， each dosing group was given the corresponding drug suspension， the immune organ coefficients of each group of rats were examined， the levels of interleukin-6（IL-6）， tumor necrosis factor-α（TNF-α）， immunoglobulin G（IgG）， amylase（AMS）， motilin（MTL）， gastrin（GAS）， Na+-K+-adenosine triphosphatase（ATPase）， aquaporin 2（AQP2）， AQP3 and AQP8 in rats were measured by enzyme-linked immunosorbent assay（ELISA）. Ultra high performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry（UPLC-Q-TOF-MS） combined with orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to search for biomarkers in the plasma samples of spleen-deficient rats by using two criteria［P<0.05 and variable importance in the projection（VIP） value>1］， and to compare the different modulatory effects of the three decoction pieces on the splenic-deficient biomarkers， and metabolic pathway analysis was conducted through the Kyoto Encyclopedia of Genes and Genomes（KEGG） database. ResultCompared with the blank group， the thymus index and spleen index of rats in the model group were significantly decreased（P<0.05）， the levels of IL-6， TNF-α， IgG and AQP2 were significantly increased（P<0.05）， the levels of AMS， GAS， MTL， AQP3， AQP8 and Na+-K+-ATPase were significantly decreased（P<0.05）. Compared with the model group， raw products， bran-fried products and rice water-processed products all increased thymus index and spleen index（P<0.05）， decreased IL-6， TNF-α， IgG and AQP2 levels（P<0.05）， and increased AMS， GAS， MTL， AQP3， AQP8 and Na+-K+-ATPase levels to different degrees. A total of 176 differential metabolites were screened in the model group compared with the blank group， of which 75， 72 and 84 biomarkers were called back by the raw products， bran-fried products and rice water-processed products， respectively（P<0.05， P<0.01）. Raw products of A. chinensis rhizoma mainly affected glycine， serine and threonine metabolism. Bran-fried products mainly affected alanine， aspartate and glutamate metabolism， D-arginine and D-ornithine metabolism. Rice water-processed products mainly affected glycine， serine and threonine metabolism， alanine， aspartate and glutamate metabolism， citrate cycle， thiamine metabolism， D-arginine and D-ornithine metabolism. ConclusionRaw products， bran-fried products and rice water-processed products of A. chinensis rhizoma all have good spleen strengthening effects， among which the effects of bran-fried products and rice water-processed products were stronger. Meanwhile， raw products has the strongest dryness， followed by bran-fried products， and the weakest dryness of rice water-processed products. The three decoction pieces are able to significantly modulate metabolic abnormalities in spleen-deficient rats， and the mechanism may be related to amino acid metabolism such as glycine， serine and threonine metabolism as well as alanine， aspartate and glutamate metabolism.

Using Liquid Chromatography-Tandem Mass Spectrometry in Detecting Plasma Lyso-GL3 Levels in Patients with Fabry Disease and the Association Analysis of Phenotype-Genotype of the Disease / 罕见病研究

ObjectiveUsing the liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine the plasma level of Lyso-GL3 in patients with Fabry disease and to analyze the clinical application of the method.MethodsThirty-nine patients with a genetic diagnosis of Fabry disease were included, and plasma levels of Lyso-GL3 were measured by LC-MS/MS analysis, and detailed clinical information of the patients was obtained including: α-galactosidase A activity, genetic variants, quantification of urine protein, mean arterial pressure, and estimation of glomerular filtration rate, and the differences in the levels of Lyso-GL3 in different clinical phenotypes and genotypes were statistically analyzed, as well as the association with clinical indicators.ResultsLyso-GL3 showed good linearity within 0.7856-400 ng/mL(r=0.9992).Further analysis of 39 Fabry disease patients diagnosed in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine showed a median Lyso-GL3 concentration of 23.6 ng/mL(4.3-92.9 ng/mL); Lyso-GL3 levels were significantly higher in patients with both the frameshift and the splicing mutations, as well as in patients with the nonsense mutations, than in patients with the missense mutations (median value 119.7 ng/mL vs. 11.9 ng/mL, P=0.006, and median value 97.0 ng/mL vs. 11.9 ng/mL, P=0.015, respectively). Whereas, association analysis revealed that Lyso-GL3 was not significantly associated with urinary protein, mean arterial pressure and estimated glomerular filtration rate.ConclusionsThe using of LC-MS/MS to quantify plasma Lyso-GL showed significant differences in Lyso-GL3 concentrations between classical and atypical phenotypes, suggesting that plasma Lyso-GL3 may help with clinical phenotypes. However, Lyso-GL3 levels is found to be overlapped between genotypes. No significant linear correlation was found between Lyso-GL3 and renal clinical indicators, suggesting the urgent need in finding a more accurate tool to assess renal involvement and prognosis in patients with Fabry disease.

Evaluation of A Liver Yin Deficiency Mouse Model Based on Untargeted Metabolomics / 中国实验方剂学杂志

ObjectiveBased on ultra performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry（UPLC-Q-TOF-MS）， to evaluate the establishment of a mouse model of liver Yin deficiency by thyroid tablet suspension combined with 10% carbon tetrachloride（CCl4） from the perspective of non-targeted metabolomics， in order to lay the foundation for the establishment of a traditional Chinese medicine（TCM） syndrome model. MethodA total of 24 mice were randomly divided into blank group and model group. The model group was given thyroid tablet suspension（0.003 2 g·kg-1） by gavage for 14 consecutive days， and 10% CCl4（5 mL·kg-1） was intraperitoneally injected once a week to establish a liver Yin deficiency model， while the blank group was injected with an equal amount of olive oil intraperitoneally and gavaged with an equal amount of distilled water， and was fed with normal feed. After the modeling was completed， 6 mice in each group were randomly selected， the levels of alanine aminotransferase（ALT）， aspartate aminotransferase（AST）， cyclic adenosine monophosphate（cAMP）， cyclic guanosine monophosphate（cGMP）， interleukin（IL）-6， IL-10， tumor necrosis factor-α（TNF-α）were measured in the mice serum， and malondialdehyde（MDA）， superoxide dismutase（SOD）， total protein（TP）， hydroxyproline（HYP） and other indicators were measured in the mice liver. Liver tissue sections were taken for hematoxylin-eosin（HE） staining and observing pathological changes. The remaining 6 mice in each group were subjected to UPLC-Q-TOF-MS combined with principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to screen differential metabolites in the liver Yin deficiency mouse model， Kyoto Encyclopedia of Genes and Genomes（KEGG） database was used to analyze the corresponding metabolic pathways of differential metabolites. ResultCompared with the blank group， mice in the model group showed liver Yin deficiency manifestations such as reduced body weight， fatigue and sleepiness， disheveled and lusterless hair， irritability. The levels of ALT， cAMP/cGMP， IL-6， AST， MDA， cAMP， TNF-α significantly increased（P<0.05， P<0.01）， while the levels of SOD， IL-10 and cGMP significantly decreased（P<0.05， P<0.01）， and the changes of HYP and TP were not statistically significant. Hepatic steatosis and distortion of the radial arrangement of the liver plate cells were seen in the section images of the model group， endogenous substances were clearly separated， and 252 differential metabolites were identified in the serum samples， which were mainly involved in the metabolic pathways of purine metabolism， steroid hormone biosynthesis and pyrimidine metabolism. A total of 229 differential metabolites were identified in the liver samples， mainly involving nucleotide metabolism， purine metabolism， steroid hormone biosynthesis， pyrimidine metabolism， antifolate resistance， insulin resistance， primary bile acid biosynthesis， prostate cancer， sulfur relay system， arachidonic acid metabolism and other metabolic pathways. ConclusionThe successful establishment of liver Yin deficiency model in mice by CCl4 combined with thyroid hormone is evaluated through the investigation of serum and liver metabolomics， combined with biochemical indicators， which provides a biological basis and experimental foundation for the Yin deficiency syndrome model of TCM.

Determination and Mechanism Prediction of Potential Active Ingredients in Erdongtang Based on UHPLC-QqQ-MS and Network Pharmacology / 中国实验方剂学杂志

ObjectiveTo establish an ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry（UHPLC-QqQ-MS） for determination of the active ingredients in Erdongtang， and to predict the targets and pathways of anti-insulin resistance action of this formula. MethodThe analysis was performed on an ACQUITY UPLC BEH C18 column（2.1 mm×100 mm， 1.7 μm） with the mobile phase of 0.1% formic acid aqueous solution（A）-acetonitrile（B） for gradient elution（0-3 min， 90%-87%A； 3-6 min， 87%-86%A； 6-9 min， 86%-83%A； 9-11 min， 83%-75%A； 11-18 min， 75%-70%A； 18-19 min， 70%-52%A； 19-22 min， 52%A； 22-25 min， 52%-5%A； 25-27 min， 5%-90%A； 27-30 min， 90%A）. The contents of active ingredients in Erdongtang was detected by electrospray ionization（ESI） and multiple reaction monitoring（MRM） mode under positive and negative ion modes. On this basis， network pharmacology was applied to predict the targets and pathways of Erdongtang exerting anti-insulin resistance effect. ResultThe 20 active ingredients in Erdongtang showed good linear relationships within a certain mass concentration range， and the precision， stability， repeatability and recovery rate were good. The results of determination showed that the ingredients with high content in 15 batches of samples were baicalein（1 259.39-1 635.78 mg·L-1）， baicalin（1 078.37-1 411.52 mg·L-1）， the ingredients with medium content were mangiferin（148.59-217.04 mg·L-1）， timosaponin BⅡ（245.10-604.89 mg·L-1）， quercetin-3-O-glucuronide（89.30-423.26 mg·L-1）， rutin（46.91-1 553.61 mg·L-1）， glycyrrhizic acid（55.97-391.47 mg·L-1）， neomangiferin（37.45-127.03 mg·L-1）， nuciferine（0.89-63.48 mg·L-1）， hyperoside（6.96-136.78 mg·L-1）， liquiritin（30.89-122.78 mg·L-1）， liquiritigenin（26.64-110.67 mg·L-1）， protodioscin（58.57-284.26 mg·L-1）， the ingredients with low content were wogonin（7.16-20.74 mg·L-1）， pseudoprotodioscin（5.49-22.96 mg·L-1）， ginsenoside Rb1（7.31-23.87 mg·L-1）， ginsenoside Rg1（10.78-28.33 mg·L-1）， ginsenoside Re（7.78-24.76 mg·L-1）， ophiopogonin D（2.08-4.29 mg·L-1）， methylophiopogonanone A（0.74-1.67 mg·L-1）. The results of network pharmacology indicated that the mechanism of anti-insulin resistance exerted by Erdongtang might be related to the phosphatidylinositol 3-kinase/protein kinase B（PI3K/Akt） signaling pathway. ConclusionThe established UHPLC-QqQ-MS has the advantages of simple sample processing， strong exclusivity and high sensitivity， and can simultaneously determine the contents of the main ingredients from seven herbs in Erdongtang， which can lay the foundation for the development of Erdongtang compound preparations. The results of the network pharmacology can provide a reference for the mechanism study of Erdongtang in the treatment of type 2 diabetes mellitus.

Simultaneous determination of 15 bile acids in Tongren niuhuang qingxin pills by UPLC-MS/MS / 中国药房

OBJECTIVE To establish a method for simultaneous determination of 15 bile acids in Tongren niuhuang qingxin pills， and to determine the contents of 15 batches of samples. METHODS Using dehydrocholic acid as internal standard， the determination was performed by ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method. The determination was performed on Hypersil GOLD C18 column with methanol-0.1% formic acid solution as the mobile phase by gradient elution at the flow rate of 0.2 mL/min. The column temperature was 40 ℃ ， and the sample size was 2 µL. Using heated electrospray ion source， parallel reaction monitoring mode scanning was performed in negative ion mode. SPSS 24.0 software was used for chemical pattern recognition analysis of content determination results. RESULTS The 15 bile acid components had a good linear relationship with peak area （all R2≥0.998 9）； their precision， repeatability and stability were all good （all RSD≤5.49%）； the average recoveries were 93.8%-105.7% （RSD was 0.5%-5.8%）. The average contents of taurocholic acid， 7-oxodeoxycholic acid， 12-dehydrocholic acid， glycocholic acid， 3-oxo-7α， 12α-hydroxy-5β-cholanoic acid， taurochenodeoxycholic acid， 3α-hydroxy- 7-oxo-5β -cholanic acid， hyocholic acid， taurodeoxycholic acid sodium salt hydrate， hyodeoxycholic acid， cholic acid， glycochenodeoxycholic acid， glycodeoxycholic acid， chenodeoxycholic acid and deoxycholic acid were 670.56， 25.97， 10.54， 280.12， 4.04， 29.81， 182.98， 813.55， 120.95， 220.31， 797.37， 18.37， 68.59， 30.13， 59.82 μg/g， respectively. Both cluster analysis and principal component analysis divided 15 batches of Tongren niuhuang qingxin pills into 2 categories， S1-S12 as one category and S13-S15 as the other category. CONCLUSIONS The established method is accurate， sensitive and specific， and can determine many types of bile acids. It also can quickly achieve the quantitative analysis of 15 bile acids in Tongren niuhuang qingxin pills， which is suitable for the quality control of this drug.

Study on Clinical Application and Supervision of LC-MS in in Vitro Diagnosis Test / 中国医疗器械杂志

From the perspective of technical evaluation, this study reviewed the current situation of application and clinical application of medical device products were detected by liquid chromatography-tandem mass spectrometry in the market in recent years. The regulatory requirements of these products in China, USA, EU and Japan were compared and analyzed, and the monitoring situation of adverse events after listing, the standards for reference and the domestic and foreign regulatory documents were combined, the clinical application and regulatory risks of the product were analyzed. The problems such as pre-treatment, system matching, adequacy of performance index requirements, inter-room consistency, reference interval and registration unit were discussed and suggestions for supervision were given, with a view to the field of product R&D and production, review and approval of supervision to provide technical reference.

Determination of 10 mycotoxins in Hippophae Fructus medicinal and edible products by ultra-performance liquid chromatography- tandem mass spectrometry / 中国中药杂志

An analytical method for 10 mycotoxins in Hippophae Fructus medicinal and edible products was established in this study, and the contamination of their mycotoxins was analyzed. First of all, the mixed reference solution of ten mycotoxins such as aflatoxin, ochratoxin, zearalenone, and dexoynivalenol was selected as the control, and the Hippophae Fructus medicinal and edible products were prepared. Secondly, based on the ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) technology, 10 mycotoxins in Hippophae Fructus medicinal and edible products were quantitatively investigated and their content was determined. Finally, the contamination of mycotoxins was analyzed and evaluated. The optimal analysis conditions were determined, and the methodological inspection results showed that the 10 mycotoxins established a good linear relationship(r>0.99). The method had good repeatability, test sample specificity, stability, and instrument precision. The average recovery rates of 10 mycotoxins in Hippophae Fructus medicinal products, edible solids, and edible liquids were 90.31%-109.4%, 87.86%-107.8%, and 85.61%-109.1%, respectively. Relative standard deviation(RSD) values were 0.22%-10%, 0.75%-13%, and 0.84%-8.5%, repsectively. Based on UPLC-MS/MS technology, the simultaneous determination method for the limits of 10 mycotoxins established in this study has fast detection speed, less matrix interference, high sensitivity, and accurate results, which is suitable for the limit examination of 10 mycoto-xins in Hippophae Fructus medicinal and edible products.

Formation and characteristics of polystyrene nanoplastic-plant protein corona / 生物工程学报

To investigate the formation of polystyrene nanoplastic-plant protein corona and its potential impact on plants, three differently modified polystyrene nanoplastics with an average particle size of 200 nm were taken to interact with the leaf proteins of Impatiens hawkeri for 2 h, 4 h, 8 h, 16 h, 24 h, and 36 h, respectively. The morphological changes were observed by scanning electron microscopy (SEM), the surface roughness was determined by atomic force microscopy (AFM), the hydrated particle size and zeta potential were determined by nanoparticle size and zeta potential analyzer, and the protein composition of the protein corona was identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The proteins were classified in terms of biological processes, cellular components, and molecular functions to study the adsorption selection of nanoplastics to proteins, investigate the formation and characteristics of polystyrene nanoplastic-plant protein corona and predict the potential impact of protein corona on plants. The results showed that the morphological changes of the nanoplastics became clearer as the reaction time extends, as evidenced by the increase in size and roughness and the enhancement of stability, thus demonstrating the formation of protein corona. In addition, the transformation rate from soft to hard protein corona was basically the same for the three polystyrene nanoplastics in the formation of protein corona with leaf proteins under the same protein concentration conditions. Moreover, in the reaction with leaf proteins, the selective adsorption of the three nanoplastics to proteins with different isoelectric points and molecular weights differed, and the particle size and stability of the final formed protein corona also differed. Since a large portion of the protein fraction in protein corona is involved in photosynthesis, it is hypothesized that the formation of the protein corona may affect photosynthesis in I. hawkeri.

Establishment and application of detection methods of dicamba in drinking water / 环境与职业医学

Background Dicamba is widely used in agricultural production in China, but it is extremely soluble in water and can be harmful to human health when it enters the body via water drinking. It is necessary to establish an accurate, sensitive, and rapid detection method to determine the residues of dicamba in domestic drinking water. Objective To establish two methods for the determination of dicamba residues in drinking water by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) respectively. Methods The conditions of the proposed method using HPLC-MS/MS included CAPCELL PAK ST chromatographic column, ammonium formate water solution and methanol as the mobile phase, and isocratic elution. The system was operated under multiple reaction monitoring mode and electrospray negative ionization mode. Trimethylsilylated diazomethane was used as a derivatizing agent for GC-MS/MS, and an external standard curve was used to evaluate the system. The residues of dicamba in seven water samples of tap water or secondary water supply from six regions in Chengdu were detected by the established systems to evaluate their applicability and to understand the status quo of dicamba residues in drinking water. Results For the HPLC-MS/MS, the linear range of dicamba was 1.00-100 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=1250.9X+2681.5, the correlation coefficient was 0.9988, the relative standard deviations were 1.23%-26.3%, the limit of detection was 0.95 μg·L−1, and the spiked recoveries were 91.8%-111%. For the GC-MS/MS, the linear range of dicamba was 0.200-10.0 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=190597X+40911, the correlation coefficient was 0.9993, the relative standard deviations were 0.64%-3.90%, the limit of detection was 0.18 μg·L−1, and the spiked recoveries were 97.3%-105%. No dicamba residue was identified in the seven water samples of tap water or secondary water supply from six regions in Chengdu by the proposed methods. Conclusion The two detection methods established in this study are sensitive and rapid, meet the requirements from the detection of dicamba residues in drinking water, and provide an experimental basis for subsequent research on the detection of dicamba residues. In the future, it is necessary to continue to pay attention to the pollution of dicamba in drinking water in Chengdu.

Determination of bongkrekic acid in corn flour by direct extraction ultra-high performance liquid chromatography tandem mass spectrometry / 公共卫生与预防医学

Objective To establish a direct extraction ultra-high performance liquid chromatography tandem mass spectrometry method for the determination of bongkrekic acid in corn flour. Methods Bongkrekic acid was directly extracted with 80% methanol from corn flour samples, and the supernatant after vortex and centrifugation was determined after passing through membrane filtration. At the same time, the corn flour samples were extracted by solid phase extraction. The determination results of the two methods were compared. Results The linearity of standard series was good within the range of2-20 μg/L, and the linearity coefficient was＞0.999. The determination result of the positive sample by direct extraction method was 193.40 mg/kg (n=6). Adding the standard to the blank sample at the levels of 2, 6, and 10 μg/L, the calculated recovery rate was 75.82% - 99.33%, and the relative standard deviation was 3.54 % - 8.45%. The detection limit of the method reached 6 μg/kg. After extraction by solid phase extraction, the determination result of the positive sample was 196.84 mg/kg (n=6). The recovery rate was 77.12% -100.83%, with a relative standard deviation of 8.32% - 9.54%. Conclusion Compared with the solid phase extraction, the direct extraction method for the extraction of bongkrekic acid from corn flour has the advantages of rapidity, simplicity, and cost savings.

Serum Metabonomics Study of Difference in Lymph Node Metastasis of Pancreatic Ductal Adenocarcinoma Based on LC-MS / 肿瘤防治研究

Objective To investigate the differential metabolites of lymph node metastasis in pancreatic ductal carcinoma (PDAC) and provide new ideas for the pathogenesis, early diagnosis and treatment of metastatic pancreatic cancer. Methods Forty serum specimens of patients with pancreatic ductal carcinoma were collected and divided into lymph node metastasis group (18 cases) and non-metastasis group (22 cases). Thirty-one serum specimens were also collected from the healthy control group. Liquid chromatographytandem mass spectrometry was used to analyze the differential metabolites and metabolic pathways between patients with PDAC and healthy controls as well as between lymph node metastasis and non-metastasis groups. Results Principal component analysis and partial least squares-discriminant analysis revealed statistically significant differences in metabolites and metabolic pathways between patients with PDAC and the healthy controls and between lymph node metastasis and non-metastasis groups. The differences in profiles were also statistically significant. Seventy-six different metabolites and 11 metabolic pathways were screened between patients with PDAC and the healthy controls, among which phenylalanine metabolism and histidine metabolism were the two most influential metabolic pathways. Four different metabolites were screened between lymph node metastasis and non-metastasis groups, and the expression of ethopropazine and phenylalanine were upregulated but the expression of tetrahydrodeoxycorticosterone and oxprenolol were downregulated. Conclusion Metabolites are significantly altered in the lymph node metastasis group of patients with PDAC compared with the non-metastasis group. Ethopropazine, phenylalanine, tetrahydrodeoxy corticosterone, and oxprenolol are potential biomarkers of lymph node metastasis in patients with PDAC.

Comparative Analysis of Serum Pharmacochemistry of Alismatis Rhizoma Before and After Salt Processing Based on UPLC-Q-TOF-MS / 中国实验方剂学杂志

ObjectiveBased on serum pharmacochemistry and ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） the transitional components in the serum of rats after intragastric administration of water extract of Alismatis Rhizoma（AR）and salt-processed Alismatis Rhizoma（SAR） were compared. MethodSD rats were randomly divided into blank group, AR group（10 g·kg-1） and SAR group（10 g·kg-1）, 3 rats in each group, the administration groups were given AR and SAR aqueous extracts by gavage, respectively, and the blank group was given an equal volume of drinking water by gavage once in the morning and once in the evening, for 3 consecutive days. Sixty minutes after the last administration, blood was collected from the eye orbits, and the serum samples were prepared. The serum samples were prepared on an ACQUITY UPLC BEH C18 column（2.1 mm×50 mm, 1.7 μm） with the mobile phase of acetonitrile（A）-0.1% formic acid aqueous solution（B） in a gradient elution（0-10 min, 10%-50% A; 10-27 min, 50%-95%A; 27-27.1 min, 95%-10% A; 27.1-30 min, 10%A）, the data were collected at a flow rate of 0.3 mL·min-1 in positive ion mode with a scanning range of m/z 100-1 200. Based on the self-constructed chemical composition library of AR, the total ion flow diagrams and secondary MS fragmentation information of the aqueous extracts of AR and SAR, as well as the administered serum and the blank serum, were compared with each other by UNIFI 1.9.2, so as to deduce the possible blood-migrating constituents and their cleavage patterns in the aqueous extracts, and the response intensity ratios of each chemical component were calculated before and after processing. ResultA total of 20 components, including 5 prototypical components and 15 metabolites, were analyzed and deduced from the serum of rats given aqueous extract of AR. And 14 components, including 5 prototypical components and 9 metabolites, were analyzed and deduced from the serum of rats given aqueous extract of SAR. Of these, 13 components were common to both of them, including 5 prototypical components and 8 metabolites. The 5 prototypical components were 16-oxoalisol A, alisol A 24-acetate, alisol A, alisol B and alisol C. The metabolites were mainly involved in phase Ⅰ metabolism（oxidation） and phase Ⅱ metabolism（glucuronidation）. There was a big change in the intensity of response of the common components before and after salt-processing, and the response intensities of the prototypical components, 16-oxoalisol A, alisol B and alisol C, were elevated, while the type and response intensity of metabolites were generally decreased, and it was hypothesized that the metabolic rate of terpenoids might be slowed down after salt-processing of AR, so that the blood-migrating constituents could participate in the metabolism of the body more in the form of prototypes. ConclusionSalt-processing of AR may promote the absorption of prototypical components into the blood by slowing down the metabolic rate of terpenoids, which can provide support for the research on material basis of AR and SAR.

Determination of pentachlorophenol in wooden chopping boards with gas chromatography-tandem mass spectrometry / 预防医学

Objective@#To optimize the determination of pentachlorophenol in wooden chopping boards through pretreatment of miniaturized samples.@*Methods@# The pretreated wooden chopping board samples were subjected to ultrasound extraction (1 mL of 0.5 mol/L K2CO3 added in 5 mL extraction solution) in 8 mL acetone and 2 mL water, followed by derivatization with 0.3 mL acetic anhydride, extraction with n-hexane and separation with DB-5ms column (30 m×0.25 mm, 0.25 μm). Gas chromatography tandem mass spectrometry (GC-MS/MS) was performed in multiple reaction monitoring (MRM) mode with quantitative analysis using the internal standard method.@*Results@#The GC-MS/MS assay showed a good linear relationship within the range of 0.01 to 0.2 µg/mL (R2>0.999), with a 0.003 mg/kg limit of detection and 0.01 mg/kg limit of quantitation. The mean recovery rates were 84.2% to 96.7% at spiked concentrations of 0.003, 0.01 and 0.03 mg/kg, with relative standard deviation of 2.2% to 6.1%.@*Conclusions@#The established GC-MS/MS assay is easy to perform, environment-friendly, highly accurate and sensitivity, which is feasible for determination of pentachlorophenol in wooden chopping boards.

Tandem expression and purification of tick-borne encephalitis virus E protein Domain Ⅲ and preparation of its polyclonal antibody / 中国生物制品学杂志

@#Objective To express and purify the E protein Domain Ⅲ(ED Ⅲ) of tick-borne encephalitis virus(TBEV) in tandem and prepare the corresponding polyclonal antibody.Methods The TBEV RNA was extracted by Trizol method,and then reversely transcribed into cDNA,which was used as template to amplify ED Ⅲ gene fragment by PCR.Two ED Ⅲ gene fragments were ligated into fusion gene by the hydrophobic flexible polypeptide(G_4S)_3 using overlapping PCR,which was then linked to prokaryotic expression vector pET-28a(+) to construct the recombinant expression plasmid pET-28a-2ED Ⅲ.After sequencing,pET-28a-2ED Ⅲ was transformed into E.coli BL21(DE3) competent cells,induced by IPTG and purified by Ni~(2+) affinity chromatography.Female New Zealand white rabbits were immunized with the renatured recombinant protein to prepare polyclonal antibody.The antibody titer was detected by indirect ELISA and the specificity was identified by Western blot.The homology of ED Ⅲ amino acid sequence between TBEV and other flaviviruses was analyzed by DNAMAN software.Results The recombinant plasmid pET-28a-2ED Ⅲ was identified by sequencing,and the amplified sequence contained two genes consistent with the E sequence of TBEV "Senzhang" strain(JQ650523.1) included on GenBank,indicating that the recombinant plasmid was constructed correctly.The recombinant 2ED Ⅲ protein was expressed mainly in the form of inclusion bodies,with a relative molecular mass of about 21 000 and a purity of 97.5%.The titer of rabbit anti-2ED Ⅲ serum polyclonal antibody was 1:10~7,which reacted specifically with TBEV whole virus.DNAMAN software alignment showed that the homology of ED Ⅲ amino acid sequences between TBEV and Japanese encephalitis virus(JEV),yellow fever virus(YFV) and Dengue virus(DENY) was 36.56%,9.28% and 30.77%,respectively.Conclusion The TBEV envelope ED Ⅲ tandem recombinant expression plasmid pET-28a-2ED Ⅲ was successfully constructed.The expressed recombinant 2ED Ⅲ protein had good reactivity and immunogenicity,and the prepared polyclonal antibody had high titer.

The trend of changes in serum vitamin A, D, and E levels during pregnancy / 中华检验医学杂志

Objective:High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to quantify the levels of vitamins A, D and E in pregnant women during the second trimester, and to investigate the change trends of serum vitamins A, D and E levels during pregnancy.Method:A total of 720 pregnant women with an average age of (29.7±4.4) years and 12-22 weeks of gestation were included from October 1, 2021 to October 30, 2022 in the obstetrics department of the People′s Hospital of Wuhan University. The concentrations of vitamins A, D and E were determined by HPLC-MS/MS. The concentration levels of each group were statistically analyzed and the deficiency rate were calculated.Results:The distribution range of vitamin A, D and E (95% CI) was 0.74-2.74 μmol/L, 2.88-25.37 ng/ml and 6.18-35.08 μmol/L, with the deficiency rates were 9.30%, 93.76% and 35.83%, respectively. Vitamin A, D and E levels in the twin group were (1.67±0.51) μmol/L, (13.18±7.44) ng/ml and 11.97 (8.85, 14.60) μmol/L, respectively. They were significantly higher than those in the singlet group (1.45±0.36) μmol/L, (10.87±5.26) ng/ml and 10.46 (6.99, 14.11) μmol/L, with statistical significance by independent sample t-test ( P<0.001). The concentration of vitamin D in the lower BMI group (<22 kg/m 2) was (12.54±5.74) ng/ml, significantly higher than that in the fat group (≥22 kg/m 2) (10.46±4.90) ng/ml, and the rank-sum test was statistically significant ( P<0.001). Conclusion:In this study, the levels of three vitamins were monitored in mid-pregnancy using HPLC-MS/MS, and the changes of serum vitamin A, D, and E levels during pregnancy were analyzed.

Development and validation of an LC-MS/MS method for the determination of 12 ceramides in human plasma / 中华检验医学杂志

Objective:To establish and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of 12 ceramides in human plasma.Methods:From October 2021 to October 2022, 438 apparently healthy individuals were enrolled in the Affiliated Hospitals of Zunyi Medical University for reference intervals of 12 ceramides in this population. Plasma samples were collected, and separated using the ACQUITY UPLC BEH C18 (2.1×50 mm, 1.7 μm) column, deuterated isotopes were used as internal standards. The mobile phase is water (containing 0.1% formic acid) and isopropanol: acetonitrile (1∶1, v/v, containing 0.1% formic acid) at a flow rate of 0.4 ml/min with gradient elution. The detection method was established using the Qlife Lab 9000 Plus triple quadrupole mass spectrometer. The performance of the method was evaluated in terms of linearity, the lower limit of quantification, precision, recovery, and stability.Results:The method passed the performance evaluation in terms of linearity, the lower limit of quantification, recovery, precision, and stability. The intra-and inter-batch precision of the 12 ceramides ranged from 1.3% to 14.3%, the correctness was verified by spiked recovery experiments, and the recoveries ranged from 91.9% to 111.0%. The lower limit of quantification ranged from 0.001 to 0.100 μmol/L. Standard curve showed good linearity (correlation coefficient r>0.990). Stability tests showed that the 12 ceramides were stable in the biological matrix and after processing under different conditions for a specified period of time. The corresponding biological reference intervals were established for each of the 12 ceramides: 0.103-0.326 μmol/L for Cer(d18∶1/16∶0), 0.018-0.098 μmol/L for Cer(d18∶1/18∶0), 0.933-3.919 μmol/L for Cer(d18∶1/24∶0), 0.243-1.072 μmol/L for Cer(d18∶1/24∶1), 0.001-0.007 μmol/L for Cer(d18∶1/14∶0), 0.022-0.095 μmol/L for Cer(d18∶1/20∶0), 0.185-0.835 μmol/L for Cer(d18∶1/22∶0), 0.003-0.022 μmol/L for Cer(d18∶0/16∶0), 0.001-0.016 μmol/L for Cer(d18∶0/18∶0), 0.017-0.156 μmol/L for Cer(d18∶0/24∶0), 0.008-0.074 μmol/L for Cer(d18∶0/24∶1), and 0.106-0.721 μmol/L for LacCer(d18∶1/24∶1). Conclusion:Our study shows that the newly established LC-MS/MS method for the determination of 12 ceramides in human plasma is reliable, and suitable for clinical application.

Development and validation of ID-LC-MS/MS method for L-tryptophan and its metabolites / 中华检验医学杂志

Objective:To establish an isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method for the determination of L-tryptophan and its metabolites in serum.Methods:The methodology was established and evaluated using serum samples collected from 166 healthy subjects undergoing physical examinations at West China Hospital from November 2022 to January 2023 were collected. Isotope-labeled markers of L-tryptophan (Trp), L-kynurenine (Kyn), and kynurenic acid (KA) were used as internal standards. After protein precipitation treatment of serum samples, LC-MS/MS was used to determine Trp, Kyn, and KA simultaneously. The selectivity, specificity, linearity, detection limit (LOD), quantification limit (LOQ), carry-over, precision, recovery rate, matrix effect, and dilution integrity of the method were evaluated.Results:The linearity of Trp, Kyn, and KA was demonstrated to be 0.999. The LODs were 0.10 μmol/L, 0.01 μmol/L and 1.00 nmol/L, respectively. The LOQs were 0.20 μmol/L, 0.04 μmol/L and 2.00 nmol/L, respectively. The intra-batch precision and inter-batch precision were below<10%. The average recovery rate and the relative matrix effect were all about 100%. The samples over the upper limit of quantitation can be diluted up to 16 times. The Trp concentration, Kyn concentration, KA concentration, Kyn/Trp ratio, and KA/Kyn ratio in serum of healthy subjects were 59.55±10.92 μmol/L, 1.85±0.43 μmol/L, 39.89±17.93 nmol/L, (31.64±8.19)×10 -3 and 21.51±6.72, respectively. Conclusion:An ID-LC-MS/MS method was successfully established for the quantitative determination of Trp, Kyn, and KA in serum. The method proved to be simple, rapid, sensitive, accurate, and reliable, providing robust support for clinical research related to these analytes.

Establishing and evaluating a robust method based on LC-MS/MS for simultaneous determination of Aβ1-42,Aβ1-40 and A β1-38 in cerebrospinal fluid / 中华检验医学杂志

Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.

Development of a LC-MS/MS method for the determination of vancomycin in human serum and validation of its clinical value / 中华检验医学杂志

Objective:The aim of our study is to develop an LC-MS/MS method using isotope internal standard for the determination of vancomycin in human blood serum and to validate its clinical value.Method:We conducted a methodological evaluation study using serum samples from 221 hospitalized patients (142 males and 79 females; mean age (59.31±15.32) years) who received treatments of vancomycin at the Sir Run Run Shaw Hospital of Zhejiang University between March 2021 and June 2022. In addition, thirty clinical residual serum samples from healthy individuals (15 males and 15 females; mean age (35.65±9.86) years) undergoing physical examination were used for methodological evaluation. The method was established using AB Sciex Triple Quad 4500 MD liquid chromatography-tandem mass spectrometer and chromatographic separation was carried out using a Phenyl-Hexyl column with gradient elution. The mobile phase was composed of 0.1% formic acid in water and methanol; the column temperature was 40℃; Vancomycin-[d12] TFA salt was used as the internal standard (IS). The sensitivity, specificity, linearity, accuracy, imprecision, matrix effect, and carry-over of the method were evaluated.Results:The detection limit of vancomycin was 0.2 mg/L and the lowest limit of quantification was 0.5 mg/L. It showed good linearity ( R2=0.998 4) in the 1 to 50 mg/L concentration range. Accuracy (recovery rate 87.45%-112.69%), intra-day and inter-day imprecision ( CV 4.91%-7.69%), internal standard standardized matrix factor (90.22%-104.29%). Carryover pollution was negligible. Of the 221 patients, the mean trough concentrations of vancomycin in serum was (13.15±8.56) mg/L. Conclusion:The LC-MS/MS method for the detection of serum vancomycin established in our laboratory meets the requirements of the reference method, and can be used for the monitoring of clinical therapeutic drugs.