Quantitative analysis of pelvic bone marrow fat using an MRI-based machine learning method for distinguishing aplastic anaemia from myelodysplastic syndromes.

AIM: To determine the prospect of using machine learning with magnetic resonance imaging (MRI) to identify aplastic anaemia (AA) and myelodysplastic syndromes (MDS). MATERIALS AND METHODS: This retrospective study included patients diagnosed with AA or MDS by pathological bone marrow biopsy, who underwent pelvic MRI with the iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation (IDEAL-IQ) between December 2016 and August 2020. Based on values of right ilium fat fraction (FF) and radiomic features extracted from T1-weighted (T1W) and IDEAL-IQ images, three machine learning algorithms including linear discriminant analysis (LDA), logistic regression (LR), and support vector machine (SVM) were used to identify AA and MDS. RESULTS: A total of 77 patients were included in the study, including 37 men and 40 women, aged 20-84 years (median age 47 years). There were 21 patients with MDS (nine men and 12 women, aged 38-84 years, median age 55 years) and 56 patients with AA (28 men and 28 women, aged 20-69 years, median age 41 years). The ilium FF of patients with AA (mean ± standard deviation [SD]: 79.23 ± 15.04%) was determined to be significantly greater compared to MDS patients (mean ± SD: 42.78 ± 30.09%, p<0.001). Selecting from the machine learning models based on ilium FF, T1W imaging and IDEAL-IQ, the IDEAL-IQ-based SVM classifier model had the best predictive ability. CONCLUSION: The combination of machine learning and IDEAL-IQ technology may enable non-invasive and accurate identification of AA and MDS.

[Clinical analysis of combined immunotherapy in patients with malignant pleural mesothelioma].

Objective: To observe the present situation, efficacy and safety of immunotherapy in patients with malignant pleural mesothelioma (MPM). Methods: The data of 39 patients with MPM in two centers from 2016 to 2021 were collected and the efficacy and safety were evaluated. According to the application of immune checkpoint inhibitors (ICIs), these patients, whose median clinical follow-up amounting to 18.97 months, were divided into immunotherapy group (19 cases) and control group (20 cases). Kaplan-Meier method and Log-rank test were used for the survival analysis. Results: The objective response rate (ORR) and the disease control rate (DCR) in the immunotherapy group is 21.05% and 79.0% respectively, compared with 10.0% and 55.0% in the control group; and the difference was not statistically significant (P>0.05). The median overall survival (OS) in the immunotherapy group was significantly longer than that in the control group (14.53 months vs 7.07 months, P=0.015), but there was no significant difference in the median progression free survival (PFS) between two groups (4.80 months vs 2.03 months, P=0.062). Single factor survival analysis showed that the nature of pleural effusion, pathological subtype and the efficacy of immunotherapy were related to both PFS and OS of the patients with MPM (P<0.05). The incidence of adverse reactions in immunotherapy group was 89.5% (17 out of 19 cases), and the most common adverse event was hematological toxicity (9 cases), followed by nausea and vomiting (7 cases), fatigue (6 cases) and skin damage (6 cases). Five patients had immune checkpoint inhibitors (ICIs) related adverse reactions with grade 1-2. Conclusions: Patients with MPM have begun to receive immunotherapy in more than 2-line mainly combined chemotherapy in the real world, and the median treatment line is 2-line. Either combined with chemotherapy or anti-angiogenesis therapy, ICI inhibitors have significant efficacy, controllable adverse events and good clinical value.

A novel kinase subverts aluminium resistance by boosting ornithine decarboxylase-dependent putrescine biosynthesis.

Rice, as one of the most aluminium (Al)-resistant cereal crops, has developed more complicated Al resistance mechanisms than others. By using forward genetic screening from a rice ethyl methanesulfonate mutant library, we obtained a mutant showing specifically high sensitivity to Al. Through MutMap analysis followed by a complementation test, we identified the causal gene, Al-related Protein Kinase (ArPK) for Al-sensitivity. ArPK expression was induced by a relatively longer exposure to high Al concentration in the roots. The result of RNA-sequencing indicated the functional disorder in arginine metabolism pathway with downregulation of N-acetylornithine deacetylase (NAOD) expression and upregulation of Ornithine decarboxylase1 (ODC1) expression in arpk mutant. Al specifically and rapidly upregulated ODC1 expression and causes overaccumulation of putrescine (Put), whereas the ODC inhibitor difluoromethylornithine reverted Al-sensitive phenotype of arpk, suggesting that overaccumulation of endogenous Put might be harmful for root growth, and that ArPK seems to act as an endogenous inhibitor of ODC1 action to maintain suitable endogenous Put level under Al treatment. Overall, we identified ArPK and its putative repressive role in controlling a novel ODC-dependent Put biosynthesis pathway specifically affecting rice Al resistance, thus enriching the fundamental understanding of plant Al resistance.

[Expression of miR-17-5p in the plasma of patients with multiple myeloma and its role in tumorigenesis and development].

Objective: To investigate the expression of miR-17-5p in the plasma of patients with multiple myeloma (MM) and its role in tumorigenesis and development. Methods: Patients diagnosed with unidentified monoclonal gammopathy of undetermined significance (MGUS) or MM in Cancer Hospital of Zhengzhou University from April 2013 to April 2018 were enrolled, as well as 20 healthy volunteers. Reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-17-5p in plasma circulation and bone marrow mononuclear cells. There were 22 cases with newly diagnosed MM (NDMM), 11 cases with complete remission MM (CRMM) and 59 case with recurrent refractory MM (RRMM). The expression levels of miR-17-5p in each group were analyzed. The correlation analysis was used to evaluate the relationship between plasma miR-17-5p and the proportion of serum M protein and bone marrow plasma cells in patients with untreated multiple myeloma. Receiver operating characteristic (ROC) curve was used to evaluate the possibility of plasma miR-17-5p as a molecular marker related to MM diagnosis. After over expression or knockdown of miR-17-5p expression, CCK-8 method was used to detect the effect of miR-17-5p on the proliferation of MM cell line. The effect of miR-17-5p on the proliferation of MM cells was detected in nude mice subcutaneous tumorigenesis experiment. Results: The expression of miR-17-5p in bone marrow mononuclear cells in NDMM and RRMM group were higher than those in healthy volunteers [1.37 (0.47, 4.87), 2.68 (1.02, 5.02) vs 1.00 (1.00, 1.00), all P<0.05], and the expression levels of miR-17-5p in plasma were also higher than those in healthy control group [1.85 (0.92, 3.51), 2.79 (1.22, 5.04) vs 1.00 (1.00, 1.00), all P<0.05]. The expression of miR-17-5p in MM cell lines such as KMS-11, RPMI-8226, H929, MM-1R, U266B1 were higher than that in bone marrow mononuclear cells of healthy control group (3.96±0.68, 1.58±0.32, 3.51±0.55, 5.08±0.76, 3.22±0.75 vs 1.00±0, all P<0.05) ; Plasma miR-17-5p was positively correlated with the ratio of serum M protein and bone marrow plasma cells (r=0.50, P<0.05; r=0.60, P<0.01). ROC curve showed that the specificity was 0.591 and the sensitivity was 0.900 of plasma miR-17-5p as a molecular marker related to diagnosis (area under ROC curve=0.74, cut-off value: 0.491). CCK-8 results showed that over expression of miR-17-5p increased the proliferation of RPMI-8226 and NCI-H929 cell lines at 72 hours compared with the control group (1.37±0.11 vs 1.07±0.09, 2.14±0.09 vs 1.82±0.11, both P<0.05), and low expression of miR-17-5p reduced the proliferation of NCI-H929 and MM-1R cell lines at 72 hours compared with the control group (1.38±0.09 vs 1.83±0.11, 1.45±0.10 vs 1.73±0.09, both P<0.05). The subcutaneous tumorigenesis experiment in nude mice showed that the tumor volume of miR-17-5p over expression group was larger than that of the control group [(1 865±181) vs (1 389±227) mm3, P<0.05], and the tumor volume of miR-17-5p low expression group was smaller than that of the control group [ (1 006±171) vs (1 389±227) mm3, P<0.05]. Conclusion: miR-17-5p may play an oncogene role in MM cell lines as a plasma molecular marker related to the development of MM disease.

[Dynamic analysis of tuberculosis specific mononuclear cells in peripheral blood of HIV patients with tuberculosis].

Objective: To evaluate the response of peripheral blood mononuclear cells (PBMCs) in patients with human immunodeficiency virus (HIV) combined with active tuberculosis (TB) to TB-specific antigen stimulation. Methods: From January to December, 2018, individuals infected with both HIV and TB (HIV/TB group) were taken as the study subjects. Individuals infected with HIV alone (HIV group), individuals infected with TB alone (TB group) and healthy people (Health control group, HC group) were taken as the control groups. PBMCs were isolated and stimulated with purified protein derivative of bacillus calmette-guerin (BCG-PPD). The expression of surface molecules in T cells (CD3+, CD4+, CD8+) and monocytes (CD14+) and the percentages of Interferon (IFN)-γ and tumor necrosis factor (TNF)-α were detected by cell surface molecular staining, direct intracellular cytokine staining and flow cytometry (CD3- lymphocytes were mainly B lymphocytes and NK cells). Analysis of non-parametric data was used to compare the data between the two groups, and paired t-test was used to compare the data before and after PPD stimulation in each group. Results: Before PPD stimulation, the percentage of IFN-γ+ CD8+ cells in the peripheral blood of HIV/TB group(mean 0.52%) was significantly lower than that in TB group(mean 0.94%, P=0.010). The TNF-α+cell percentages in CD3+, CD4+, CD8+, or CD14+ cells in the HIV/TB group(mean 19.2%) were significantly lower than those in the HIV group(mean 31.9%, P=0.002). The percentage of TNF-α secreted by monocytes in the HIV group was significantly lower than that in the HC group. The percentages of IFN-γ+ CD8+ and IFN-γ+ CD3- cells in the peripheral blood of the TB group (mean 0.94%) were significantly higher than thoset in the HC group(mean 0.51%, P=0.020), while the percentages of TNF-α+ cells in each subsets of PBMCs were significantly lower than those in the HC group. After PPD stimulation, the percentage of IFN-γ+ CD8+ cells in the HIV/TB group was significantly lower than that in the TB group(P=0.008), and the change was more marked than that before stimulation. The percentage of IFN-γ+ CD8+ cells in the HIV group(mean 0.20%) was lower than that in the HC group (mean 0.52%, P=0.044). The percentage of IFN-γ+ CD3- in the TB group was significantly higher than in the HC group. There were no significant differences in TNF-α+ cell percentages in the 3 groups compared with the control group after PPD stimulation. The percentages of IFN-γ+ CD4+ cells in the HC and the TB groups were significantly increased after PPD stimulation in each group (P=0.002, P=0.001, respectively). However, there were no significant differences of IFN-γ+ CD4+ cell percentages in the HIV/TB group and the HIV group. The percentages of TNF-α production by monocytes were significantly increased after PPD stimulation in all groups. Conclusions: Chronic Mycobacterium tuberculosis (MTB) infection reduced the ability of PBMCs to produce TNF-α. For patients with TB infection, the production of TNF-α was reduced when combined with HIV infection. The capacity of CD8+ and CD3- lymphocytes to produce IFN-γ was increased in TB patients, while the capacity of CD8+ T cells to produce IFN-γ was decreased with co-infection of HIV. Infection of HIV weakened the immune response to MTB infection, which made the clinical diagnosis and treatment of TB more difficult.

Mass Spectrometry Imaging and Its Application in Forensic Toxicology.

ABSTRACT: Mass spectrometry imaging （MSI） is a new imaging technology that can simultaneously detect and record the spatial distribution information of multiple molecules on the sample surface without labeling. The main principle of MSI is to combine mass spectrometry with imaging technology and irradiate the sample slice with ion beam or laser to ionize the molecules on its surface, obtain the mass spectrometry signal through the detector, convert the obtained data into pixel points by the imaging software, and then construct the spatial distribution image of the target compound on the tissue surface. The sample preparation for MSI include： sample collection and storage, tissue section, tissue pretreatment, selection and application of matrix. At present, this technology has been widely used in the fields of biomedicine, new drug development and proteomics, and its application in the field of forensic toxicology has also gradually attracted attention. This article reviews the principles and sample preparation process of MSI, describes the application of MSI in abused substances and metabolites of various material matrices, herbal mixtures, latent fingerprints, hair and animal and plant tissues, and discusses the prospects of the application of this technology in forensic toxicology, in order to provide ideas and references for the application of MSI technology in forensic toxicology.

[Research Advances in the Monitoring of New Psychoactive Substances in Municipal Wastewater].

ABSTRACT: In recent years, as the third-generation of drugs, new psychoactive substances （NPS） have expanded rapidly and become a serious concern for China's anti-drug prevention and control system. As a new drug monitoring technology in the current anti-drug field, wastewater analysis is an objective, real-time, accurate, convenient and effective drug monitoring method. In recent years, it has gradually been applied to the monitoring of NPS. This study summarizes wastewater sample collection, target stability research, wastewater sample pretreatment, wastewater sample analysis methods, target NPS consumption calculations and actual monitoring applications, with a view to the construction of a monitoring system for NPS in wastewater, real-time and accurate grasp of information on the use of NPS in cities, the reflection of the actual consumption of different types of NPS and consumption trends in a short period of time, and prediction of the development trend of abused use, which is of great significance for combating NPS crimes, serving and guaranteeing the personal safety of the people, and maintaining social stability.

Analysis Methods of Common Herbicides in Biological Material and Research Progress.

ABSTRACT: Herbicides are a kind of chemical or biological agents that can effectively destroy or inhibit weed growth. Because of the widespread and frequent use of herbicides, herbicide poisonings have often been reported. At present, the main species reported to have caused poisoning are paraquat, diquat, glyphosate, and glufosinate. The main instrumental analysis method is LC-MS. This paper reviews the research progress on analysis methods of common herbicides in biological material and their application, summarizes the sample pretreatment and instrumental analysis situation of qualitative and quantitative analysis of herbicides in biological material, and collects test data of actual poisoning cases, to provide reference for clinical diagnosis and treatment and forensic identification of herbicide poisoning.

[Research Progress on Metabolite Identification of Synthetic Cannabinoid New Psychoactive Substances].

ABSTRACT: Synthetic cannabinoids are currently a class of new psychoactive substances with the largest variety and most abused. Metabolite identification research can provide basic data for monitoring synthetic cannabinoids abuse, which is the current research hotspot. The main trend of structural modification of synthetic cannabinoid is to replace the fluorine atom on pentyl indole or indazole cyclopentyl with hydrogen atom, which greatly improves the biological activity of the compound. The main metabolic reactions include hydroxylation, fluoropentyl oxidative, ester hydrolyze, amide hydrolysis. Liquid chromatography-high resolution mass spectrometry has become the preferred choice for the structural identification of metabolites. This review mainly summarizes research on metabolism software prediction and human hepatocyte model, human liver microsomes model, rat in vivo model, zebrafish model and fungus C. elegans model in metabolite identification based on the structure and classification of synthetic cannabinoids.

[Metabolism of New Psychoactive Substances 4F-MDMB-BUTINACA in Zebrafish].

ABSTRACT: Objective To study the metabolic transformation pathways of 4F-MDMB-BUTINACA in vivo by establishing zebrafish models. Methods Six adult zebrafish were randomly divided into blank control group and experimental group, with three fish in each group. After the zebrafish in the experimental group were exposed to 1 µg/mL 4F-MDMB-BUTINACA for 24 h, they were transferred to clean water and cleaned three times, then pretreated for instrumental analysis. The zebrafish in blank control group were not exposed to 4F-MDMB-BUTINACA. Mass spectrometry and structural analysis of 4F-MDMB-BUTINACA and its metabolites were conducted by liquid chromatography-high resolution mass spectrometry and Mass Frontier software. Results A total of twenty-six metabolites of 4F-MDMB-BUTINACA were identified in zebrafish, including eighteen phase Ⅰ metabolites and eight phase Ⅱ metabolites. The main metabolic pathways of phase Ⅰ metabolites of 4F-MDMB-BUTINACA in zebrafish were ester hydrolysis, N-dealkylation, oxidative defluorination and hydroxylation, while the main metabolic pathway of phase Ⅱ metabolites was glucuronidation. Conclusion Metabolite Md24 （ester hydrolysis） and Md25 （ester hydrolysis combined with dehydrogenation） would be recommended to be potentially good biomarkers for abuse of 4F-MDMB-BUTINACA.

[Analysis and Application of Seven Common New Psychoactive Substances of Synthetic Cannabinoids in Hair].

ABSTRACT: Objective To establish a detection method for common new psychoactive substances of synthetic cannabinoids in hair with ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. Methods In the 1 mL of internal standard methanol solution, 20 mg hair was added. After cryogenic grinding and ultrasonic extraction, the extract was separated by ACQUITY UPLC HSS T3 column （100 mm×2.1 mm, 1.8 µm）. The mobile phase A was aqueous solution that composed of 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile. The mobile phase B was acetonitrile. Electrospray ionization source in positive ion mode was used for data acquisition in multi-reaction monitoring （MRM） mode. Results The seven common new psychoactive substances of synthetic cannabinoids in hair had a good linear relationship within their respective linear ranges （r>0.99）, the limits of detection were 0.5-2 pg/mg, the limits of quantification were 1-5 pg/mg, the intra-day and inter-day precisions were 0.1%-12.6%, the intra-day and inter-day accuracies were 89.2%-110.7%, the recovery rates were 52.3%-93.3%, and the matrix effects were 19.1%-95.2%. Conclusion The established method has a simple sample preparation process and high sensitivity. It is suitable for qualitative and quantitative analysis of common new psychoactive substances of synthetic cannabinoids in hair.

Identification of Cannabis Sativa L. Based on rbcL Sequence.

ABSTRACT: Objective To assess the feasibility of the rbcL sequence of chloroplast DNA as a genetic marker to identify Cannabis sativa L. Methods The rbcL sequences in 62 Cannabis sativa L. samples, 10 Humulus lupulus samples and 10 Humulus scandens DNA samples were detected, and 96 rbcL sequences of the Cannabaceae family were downloaded from Genbank. Sequence alignment was performed by MEGA X software, the intraspecific and interspecific Kimura-2-Parameter （K2P） genetic distances were calculated, and the system clustering tree was constructed. Results The rbcL sequence length acquired by sequencing of Cannabis sativa L. and Humulus scandens were 617 bp and 649 bp, respectively, and two haplotypes of Cannabis sativa L. were observed in the samples. The BLAST similarity search results showed that the highest similarity between the sequences acquired by sequencing and Cannabis sativa L. rbcL sequences available from Genbank was 100%. The genetic distance analysis showed that the maximum intraspecific genetic distance （0.004 9） of Cannabis sativa L. was less than the minimum interspecific genetic distance （0.012 9）. The results of median-joining network and system clustering tree analysis showed that Cannabis sativa L. and other members of the Cannabaceae family were located in different branches. Conclusion The rbcL sequence could be used as a DNA barcode for identifying Cannabis sativa L., and combined with comparative analysis of the rbcL sequence and system cluster analysis could be a reliable and effective detection method for Cannabis sativa L. identification in forensic investigation.

[Influence of Halogenated Hydroxyl-Alkanes Inhalation Anesthetic on the Determination of Ethanol Content in Blood].

ABSTRACT: Objective To study the influence of halogenated hydroxyl-alkanes inhalation anesthetic on the determination of ethanol content in blood. Methods Halogenated hydroxyl-alkanes were analyzed by headspace gas chromatography with double column confirmatory detection method. The influence of halogenated hydroxyl-alkanes on determination of ethanol content in blood sample by headspace gas chromatography was explored under the different detection conditions of KB-BAC1/ KB-BAC2 and J&W DB-ALC1/DB-ALC2 gas chromatographic column. Results The retention time of sevoflurane and enflurane was similar to that of ethanol and tert butanol respectively when using the J&W DB-ALC1/DB-ALC2 gas chromatographic column, and interfered with the detection of ethanol content in blood; only J&W DB-ALC1 gas chromatographic column can separate the sevoflurane and ethanol components, so as to eliminate their influence on the detection of ethanol content in blood. When using KB-BAC1/KB-BAC2 gas chromatographic column, the retention time of sevoflurane, isoflurane and ethanol is similar, especially that of sevoflurane and ethanol, and sevoflurane obviously interferes with the determination of ethanol content in blood. Conclusion Halogenated hydroxy-alkanes interfere with determination of ethanol content in blood by headspace gas chromatography. The interference can be discriminated effectively by choosing the suitable chromatographic column and double column confirmatory detection.

Microphthalmia-associated transcription factor up-regulates acetylcholinesterase expression during melanogenesis of murine melanoma cells.

Acetylcholinesterase (AChE) hydrolyzes the neurotransmitter acetylcholine in neurons. However, AChE has been proposed to also have nonneuronal functions in different cell types. Here, we report that AChE is expressed in melanocytes and melanoma cells, and that the tetrameric (G4) form is the major AChE isoform in these cells. During melanogenesis of B16F10 murine melanoma cells, AChE levels decreased markedly. The differentiation of melanoma cells led to (i) an increase in melanin and tyrosinase, (ii) a change in intracellular cAMP levels, and (iii) a decrease in microphthalmia-associated transcription factor (MITF). We hypothesized that the regulation of AChE during melanogenesis is mediated by two transcription factors: cAMP-response element-binding protein (CREB) and MITF. In melanoma cells, exogenous cAMP suppressed AChE expression and the promoter activity of the ACHE gene. This suppression was mediated by a cAMP-response element (CRE) located on the ACHE promoter, as mutation of CRE relieved the suppression. In melanoma, MITF overexpression induced ACHE transcription, and mutation of an E-box site in human ACHE promoter blocked this induction. An AChE inhibitor greatly enhanced acetylcholine-mediated responses of melanogenic gene expression levels in vitro; however, this enhancement was not observed in the presence of agonists of the muscarinic acetylcholine receptor. These results indicate that ACHE transcription is regulated by cAMP-dependent signaling during melanogenesis of B16F10 cells, and the effect of this enzyme on melanin production suggests that it has a potential role in skin pigmentation.

Establishment and Its Application of UPLC-MS/MS Method for 20 Fentanyl-related Substances in Blood.

ABSTRACT: Objective To establish an ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） rapid determination method for simultaneous analysis of 20 fentanyl-related substances in blood. Methods With fentanyl-D5 as an internal standard, the blood was extracted by liquid-liquid extraction （LLE）, then separated with an ACQUITY UPLC HSS T3 chromatographic column, and finally 20 fentanyl-related substances were simultaneously analyzed with multiple reaction monitoring （MRM） mode. Results The limits of detection （LOD） of all compounds were 0.02-0.03 ng/mL, and the limits of quantitation （LOQ） were 0.05-0.2 ng/mL. Within the mass concentration range of 0.05-40 ng/mL, 20 fentanyl-related substances had a good linear relationship, and correlation coefficients were larger than 0.99. The accuracy of the method was 87.69%-114.68% and the extraction recovery rate was 85.35%-101.80%, and no significant matrix effect was observed. The established method was successfully applied to the detection of sufentanil in rat blood after sufentanil was injected. Sufentanil could still be detected in blood of rats 10 h after sufentanil injection. Conclusion The established method has the advantages of simple pretreatment, high sensitivity and good selectivity, and can be used for the determination of fentanyl-related substances in forensic toxicology analysis.

Rapid Determination of Cocaine and Its Metabolite Benzoylecgonine in Hair by LC-MS/MS.

OBJECTIVES: To establish a rapid determination method with LC-MS/MS for cocaine and its metabolite benzoylecgonine in hair. METHODS: Deuterated internal standards （cocaine-D3 and benzoylecgonine-D8） were added to the decontaminated hair. After the extraction by ultrasonication with methanol, the compounds were separated by the Restek Allure PFP propyl column, and cocaine and benzoylecgonine were simultaneously analysed in multiple reaction monitoring mode. RESULTS: The cocaine and benzoylecgonine in hair showed a good linearity in the range of mass fraction between 0.02 and 10.00 ng/mg with the limits of detection of 0.01 ng/mg. CONCLUSIONS: The developed method is simple and rapid with a good selectivity, which is suitable for the determination of cocaine and its metabolite benzoylecgonine in hair.

[Identification of New Designer Benzodiazepine Diclazepam in Drug Facilitated Sexual Assault].

OBJECTIVES: To identify the new designer drugs which are totally unknown and not in the routine testing list by the technologies such as high-resolution mass spectrometry in drug facilitated sexual assault, in order to solve the problem in actual cases. METHODS: The milky fluid from an actual case was extracted and analyzed using LC-QE, ¹H-NMR and GC-MS, respectively. The accurate masses and cluster ions isotope patterns of unknown compound were obtained by LC-QE. The molecular formula was confirmed as C16H12C2N2O based on the protons number of ¹H-NMR. The isomers diclazepam and 4-chlorodiazepam were separated and detected with GC-MS. RESULTS: The new designer benzodiazepine as diclazepam in the milky fluid was identified. The results provided direct evidence for the investigation and qualitative analysis of such cases. CONCLUSIONS: The combined application of various methods, including LC-QE, ¹H-NMR and GC-MS, can be used to detect unknown new psychoactive substances.

[The Role of Segmental Analysis of Clonazepam in Hair in Drug Facilitated Cases].

OBJECTIVES: To infer the frequency of dosage and medication history investigate of the victims in drug facilitated cases by the segmental analysis of clonazepam in hair. METHODS: Freezing milling under liquid nitrogen environment combined with ultrasonic bath was used as sample pretreatment in this study, and liquid chromatography-tandem mass spectrometry was used for the segmental analysis of the hair samples collected from 6 victims in different cases. The concentrations of clonazepam and 7-aminoclonazepam were detected in each hair section. RESULTS: Clonazepam and its metabolite 7-aminoclonazepam were detected in parts of hair sections from the 6 victims. The occurrence time of drug peak concentration was consistent with the intake timing provided by victims. CONCLUSIONS: Segmental analysis of hair can provide the information of frequency of dosage and intake timing, which shows an unique evidential value in drug facilitated crimes.

[Evaluation of Brodifacoum-induced Toxicity by Metabonomics Approach Based on HPLC-TOF-MS].

OBJECTIVES: To analyse the metabolic changes in urine of rats with brodifacoum intoxication, and to reveal the molecular mechanism of brodifacoum-induced toxicity on rats. METHODS: By establishing a brodifacoum poisoning rats model, the urine metabolic profiling data of rats were acquired using high performance liquid chromatography-time of flight mass spectrometry （HPLC-TOF-MS）. The orthogonal partial least squares analysis-discrimination analysis （OPLS-DA） was applied for the multivariate statistics and the discovery of differential metabolites closely related to toxicity of brodifacoum. RESULTS: OPLS-DA score plot showed that the urinary metabolic at different time points before and after drug administration had good similarity within time period and presented clustering phenomenon. Comparing the urine samples of rats before drug administration with which after drug administration, twenty-two metabolites related to brodifacoum-induced toxicity were selected. CONCLUSIONS: The toxic effect of brodifacoum worked by disturbing the metabolic pathways in rats such as tricarboxylic cycle, glycolysis, sphingolipid metabolism and tryptophan metabolism, and the toxicity of brodifacoum is characterized of accumulation effect. The metabonomic method based on urine HPLC-TOF-MS can provide a novel insight into the study on molecular mechanism of brodifacoum-induced toxicity.