OBJECTIVES: Tiletamine, a veterinary anesthetic, has emerged as a novel psychoactive substance and has been abused in many parts of the world, causing great harm to public health. However, the sensitivity of existing detection methods cannot meet the needs of forensic practice. This study aims to establish an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of tiletamine and its metabolite desethyltiletamine in human biological samples, and to verify its applicability in forensic practice. METHODS: SKF_525A was used as the internal standard. Biological samples were extracted with acetonitrile containing 1 ng/mL SKF_525A, vortexed for 10 min, ultrasonicated for 20 min, centrifuged at 10 000 r/min for 10 min, and 500 μL of the supernatant was filtered through a 0.22 μm membrane. Analyses were performed using an ACQUITY UPLC H-Class PLUS system and an XEVO TQ-S Micro triple quadrupole mass spectrometer. An ACQUITY UPLC^® BEH C18 (1.7 µm, 2.1 mm×100 mm) column at a flow rate of 0.3 mL/min was used, and four mobile phase systems were tested to optimize separation. Detection used positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode, with quantifier ion transitions of mass to charge 224.043→179.016 for tiletamine and mass to charge 196.08→151.06 for desethyltiletamine. Calibration curves were established over 0.1-200 ng/mL in spiked blood samples. The linear range, limit of detection (LOD), and limit of quantification (LOQ) were determined. Low (5 ng/mL), medium (20 ng/mL), and high (100 ng/mL) concentrations of tiletamine were spiked into blood, liver, and kidney to evaluate precision, accuracy, matrix effect, recovery, and stability. Finally, actual forensic case samples were tested to validate applicability. RESULTS: The established UPLC-MS/MS method achieved simultaneous detection of tiletamine and desethyltiletamine in human biological samples, with retention times of 3.42 min and 2.82 min, respectively. Using mobile phase A (20 mmol/L ammonium acetate and 0.1% formic acid in water) and mobile phase B (acetonitrile) produced the best separation. In blood, tiletamine showed good linearity from 0.1-200 ng/mL (r=0.992, R²=0.983), LOD 0.03 ng/mL, LOQ 0.1 ng/mL, recovery 92%-107%, and matrix effect 71%-99%. In liver and kidney, recoveries were 91%-98% and 93%-104%, and matrix effects were 69%-96% and 72%-100%, respectively. Intra- and inter-day precision [expressed as relative standard deviation (RSD)] and accuracy [expressed as relative error (RE)] were within 15%, and samples were stable at -20 ℃. Tiletamine was detected in actual case samples at 0.37 μg/mL (blood), 0.15 μg/g (liver), 0.11 μg/g (kidney) in case 1, and 8.75 ng/mL (blood) in case 2; desethyltiletamine was also detected in blood. CONCLUSIONS The UPLC-MS/MS method is efficient, accurate, and sensitive, and is suitable for detecting tiletamine and desethyltiletamine in human biological samples.
Tandem Mass Spectrometry/methods* ; Humans ; Chromatography, High Pressure Liquid/methods* ; Substance Abuse Detection/methods* ; Liquid Chromatography-Mass Spectrometry

Objective This study analyzed the chemical structures of two unknown substances in e-liquid using methods such as nuclear magnetic resonance(NMR),infrared spectroscopy(IR),and mass spectrometry(MS).Methods After separating,purifying,and freeze-drying two suspicious substances from e-liquid,GC-MS analysis was used to obtain the mass spectrum characteristic ion fragments and fragmentation patterns of unknown compounds.The precise mass numbers were measured by high-resolution mass spectrometry,and proton numbers and their assignments,carbon types,and fluorine atom numbers and positions were obtained by combining 1HNMR,13CNMR,and 19FNMR.The functional groups were then analyzed by infrared spectroscopy.Results Through data analysis,the molecular formulas of the two suspicious substances are C13H13FN2O2 and C14H15FN2O2,respectively.Their structures were determined to be etomidate derivatives:1-(o-fluoromethylphenyl)imidazole-5-carboxylic acid methyl ester and 1-(o-fluoromethylphenyl)imidazole-5-carboxylic acid ethyl ester.Conclusion The structural data of two substances obtained in this study in terms of mass spectrometry,nuclear magnetic resonance,and infrared spectroscopy provide support for combating crimes involving the two substances,and provide reference for the regulation and detection of the two drugs.

ObjectiveTo explore the impacts of material type and loading volume of rigid containers on the hydrogen peroxide low temperature plasma sterilization of thoracoscopic instruments, to identify the best rigid containers and loading volume of thoracoscopic instruments. MethodsThoracoscopic instruments sterilized by STERRAD^® 100NX hydrogen peroxide low temperature plasma in Shanghai Pulmonary Hospital affiliated to Tongji University from August to September 2024 were selected as the research items. According to the material of rigid containers, the instruments were divided into polyethylene case group (A), stainless steel case group (B) and silicone resin case group (C). In terms of the loading volume, the rigid containers were divided into (loading capacity <80%) groups of 8, 10 and 12 instruments. The results of physical monitoring, the first type of chemical indicator card monitoring, and the five types of card luminal chemical process challenge device (PCD) monitoring of the 9 groups of A8, A10, A12, B8, B10, B12, C8, C10 and C12 were compared and evaluated. ResultsCompared to A8, A10 A12, C8, C10 or C12 groups, the thoracoscope instruments in the stainless steel containers in B8, B10 or B12 group had higher hydrogen peroxide concentrations and shorter elapsed time in the pressure check phases 1 and phases 2, with the differences statistically significant (P<0.05), followed by the silicone resin case group and the polyethylene case group. The nine groups of physical parameter monitoring, the first type of chemical indicator monitoring, and the five types of chemical PCD monitoring for lumen sterilization achieved 100% qualification rates, and there were no significant differences in the qualified rates of sterilization among the 9 groups (P>0.05). ConclusionWhen using hydrogen peroxide low temperature plasma to sterilize thoracoscopic instruments, it is recommended to use stainless steel or silicone resin rigid containers with a controlled loading capacity (≤12) to ensure optimal sterilization quality.

Objective:To explore the effects of smoking on peripheral regulatory T cells (Tregs), transforming growth factor beta1 (TGF-β 1) and interleukin-10 (IL-10) in elderly patients with non-small cell lung cancer (NSCLC). Methods:This was a cross-sectional study. A total of 43 elderly patients (≥60 years old) who were hospitalized in the Department of Geriatrics Medicine, Guangzhou First People′s Hospital from January 2018 to December 2024 and were newly diagnosed with NSCLC were recruited. According to smoking history, patients were divided into non-smoking group (15 cases), low smoking group (13 cases, smoking index<400) and high smoking group (15 cases, smoking index≥400). Venous blood samples were collected from participants, plasma and cells were separated. Flow cytometry was used to measure the proportions of Tregs and the expression of forkhead box P3 (Foxp3) in peripheral blood. Plasma levels of TGF-β 1 and IL-10 were measured by enzyme-linked immunosorbent assay. The effects of smoking on peripheral Tregs, TGF-β 1, and IL-10 in elderly patients with NSCLC were analyzed. Data were analyzed by one-way ANOVA, rank-sum test, and Fisher′s exact test. Results:The proportions of Tregs in non-smoking group, low smoking group and high smoking group were 2.50% (2.32%, 2.81%), 2.83% (2.48%, 3.72%), and 3.01% (2.37%, 3.73%), respectively, and there were no statistically significant differences among the three groups ( H=3.845, P>0.05). The proportions of Foxp3 +Tregs were (3.72±0.84)%, (4.64±1.10)%, and (4.68±1.27%), respectively. The mean fluorescence intensities (MFI) of Foxp3 were 123.0 (108.0, 128.0), 131.0 (123.5, 350.0), and 222.0 (141.0, 311.0), respectively. Both the proportions of Foxp3 +Tregs and the MFI of Foxp3 were higher in low smoking group and high smoking group than those in non-smoking group (all P<0.05). However, there were no significant differences between low smoking group and high smoking group (all P>0.05). The concentrations of IL-10 were 2.27 (1.42, 3.95), 3.42 (2.30, 5.08), and 3.26 (2.35, 6.28) ng/L, respectively. There were no statistically significant differences among the three groups ( H=2.930, P>0.05). The concentrations of TGF-β 1 were (10.72±9.37), (13.46±10.39), and (25.28±16.67) ng/ml, respectively. The concentration of TGF-β 1 in high smoking group was higher than that in non-smoking group and low smoking group (all P<0.05). However, there was no statistically significant difference between low smoking group and non-smoking group ( P>0.05). Conclusions:Smoking intensity may be correlated with the immunosuppressive function of Tregs in elderly patients with NSCLC. Higher smoking levels are associated with increased Foxp3 expression in Tregs and elevated plasma levels of TGF-β 1, potentially enhancing the immunosuppressive function of Tregs.

Objective This study analyzed the chemical structures of two unknown substances in e-liquid using methods such as nuclear magnetic resonance(NMR),infrared spectroscopy(IR),and mass spectrometry(MS).Methods After separating,purifying,and freeze-drying two suspicious substances from e-liquid,GC-MS analysis was used to obtain the mass spectrum characteristic ion fragments and fragmentation patterns of unknown compounds.The precise mass numbers were measured by high-resolution mass spectrometry,and proton numbers and their assignments,carbon types,and fluorine atom numbers and positions were obtained by combining 1HNMR,13CNMR,and 19FNMR.The functional groups were then analyzed by infrared spectroscopy.Results Through data analysis,the molecular formulas of the two suspicious substances are C13H13FN2O2 and C14H15FN2O2,respectively.Their structures were determined to be etomidate derivatives:1-(o-fluoromethylphenyl)imidazole-5-carboxylic acid methyl ester and 1-(o-fluoromethylphenyl)imidazole-5-carboxylic acid ethyl ester.Conclusion The structural data of two substances obtained in this study in terms of mass spectrometry,nuclear magnetic resonance,and infrared spectroscopy provide support for combating crimes involving the two substances,and provide reference for the regulation and detection of the two drugs.

Objective:To explore the effects of smoking on peripheral regulatory T cells (Tregs), transforming growth factor beta1 (TGF-β 1) and interleukin-10 (IL-10) in elderly patients with non-small cell lung cancer (NSCLC). Methods:This was a cross-sectional study. A total of 43 elderly patients (≥60 years old) who were hospitalized in the Department of Geriatrics Medicine, Guangzhou First People′s Hospital from January 2018 to December 2024 and were newly diagnosed with NSCLC were recruited. According to smoking history, patients were divided into non-smoking group (15 cases), low smoking group (13 cases, smoking index<400) and high smoking group (15 cases, smoking index≥400). Venous blood samples were collected from participants, plasma and cells were separated. Flow cytometry was used to measure the proportions of Tregs and the expression of forkhead box P3 (Foxp3) in peripheral blood. Plasma levels of TGF-β 1 and IL-10 were measured by enzyme-linked immunosorbent assay. The effects of smoking on peripheral Tregs, TGF-β 1, and IL-10 in elderly patients with NSCLC were analyzed. Data were analyzed by one-way ANOVA, rank-sum test, and Fisher′s exact test. Results:The proportions of Tregs in non-smoking group, low smoking group and high smoking group were 2.50% (2.32%, 2.81%), 2.83% (2.48%, 3.72%), and 3.01% (2.37%, 3.73%), respectively, and there were no statistically significant differences among the three groups ( H=3.845, P>0.05). The proportions of Foxp3 +Tregs were (3.72±0.84)%, (4.64±1.10)%, and (4.68±1.27%), respectively. The mean fluorescence intensities (MFI) of Foxp3 were 123.0 (108.0, 128.0), 131.0 (123.5, 350.0), and 222.0 (141.0, 311.0), respectively. Both the proportions of Foxp3 +Tregs and the MFI of Foxp3 were higher in low smoking group and high smoking group than those in non-smoking group (all P<0.05). However, there were no significant differences between low smoking group and high smoking group (all P>0.05). The concentrations of IL-10 were 2.27 (1.42, 3.95), 3.42 (2.30, 5.08), and 3.26 (2.35, 6.28) ng/L, respectively. There were no statistically significant differences among the three groups ( H=2.930, P>0.05). The concentrations of TGF-β 1 were (10.72±9.37), (13.46±10.39), and (25.28±16.67) ng/ml, respectively. The concentration of TGF-β 1 in high smoking group was higher than that in non-smoking group and low smoking group (all P<0.05). However, there was no statistically significant difference between low smoking group and non-smoking group ( P>0.05). Conclusions:Smoking intensity may be correlated with the immunosuppressive function of Tregs in elderly patients with NSCLC. Higher smoking levels are associated with increased Foxp3 expression in Tregs and elevated plasma levels of TGF-β 1, potentially enhancing the immunosuppressive function of Tregs.

Objective:To evaluate the clinical outcomes and define the indications for a one-stage mandibular reconstruction technique that combines iliac bone flaps with immediate implant-based den-tures,and to assess both the accuracy of surgical planning and the long-term success of the procedure.Methods:A total of ten patients underwent the procedure at Peking University Hospital of Stomatology between June 2020 and August 2023.The preoperative biopsy pathology of all the patients confirmed a benign tumor.In this technique,iliac bone flaps were used for mandibular reconstruction,and immediate implant-based dentures were placed during the same surgical session.Various outcome measures were evaluated,including the accuracy of the surgical reconstruction,implant placement deviations(entry point,apical point,depth,and angle),and long-term outcomes,such as cervical bone resorption,im-plant survival,and the cumulative survival rate.Results:Thirty-eight implants were successfully inserted into the iliac flaps of the ten patients.The median follow-up duration was 23.5 months,and no signifi-cant complications occurred during the follow-up period,such as infections,titanium plate exposure,im-plant loosening,or damage to the implants and dentures.The accuracy of preoperative virtual surgical planning(VSP)was highly reliable.The repeatability of the VSP model compared to the postoperative reconstructed mandible was as follows:67.82％±10.16％within 1 mm,82.14％±6.58％within 2 mm,and 90.61％±4.62％within 3 mm.The average maximum deviation from the plan was(6.10±0.89)mm,with an average overall deviation of(1.14±0.31)mm.For the implants,deviations in critical pa-rameters were as follows:entry point deviation was(2.02±0.58)mm,apical point deviation was(2.25±0.66)mm,depth deviation was(1.26±0.51)mm,and angular deviation was 1.84°±1.10°.The im-plant survival rate remained 100％during the follow-up,with a cumulative survival rate of 97.37％from 1 to 4 years.Average cervical bone resorption was 0.94 mm.Conclusion:The combination of iliac bone flaps with immediate implant-based dentures for one-stage mandibular reconstruction demonstrated pro-mising clinical outcomes,including high implant survival and minimal complications.This technique proved to be safe and reliable for mandibular reconstruction.However,further studies with larger sample sizes and longer follow-up periods are necessary to confirm the long-term efficacy and optimal indications for this procedure.

Aim To explore the mechanism of oxidized lipoprotein(a)(oxLp(a))inducing pyroptosis of vascu-lar endothelial cells.Methods After incubating human umbilical vein endothelial cells(HUVEC)with 100 mg/L ox-Lp(a)for 24 hours,Western blot and RT-qPCR was used to detect pyroptosis related proteins,pro-inflammatory cytokines,mitochondrial related proteins NRF1,NRF2,PGC-1α and mitochondrial gene cytochrome b(CYTB),ELISA was used to detect the levels of inflammatory factors,scanning electron microscopy was used to detect cell membrane rup-ture,transmission electron microscopy was used to detect mitochondrial morphology,Hoechst33342/PI staining was used to detect cell apoptosis,MitoSOX probe was used to detect mitochondrial reactive oxygen species(mtROS),Flu-4AM probe was used to detect calcium ions,JC-1 probe was used to detect mitochondrial membrane potential(MMP),and Calcein AM staining was used to detect mitochondrial permeability transition pore(mPTP).Transfecting HUVEC with CYTB overexpressing lentivirus and analyzing its effects on oxLp(a)induced pyroptosis and mitochondrial function.Results After treatment with oxLp(a),the expression of NLRP3,pro-Caspase-1,Caspase-1,GSDMD and GSDMD-N proteins re-lated to pyroptosis were significantly increased(P＜0.05);the protein and mRNA levels of CYTB and pro-inflammatory cy-tokine IL-1β,IL-18 were significantly increased(P＜0.05).Small pores appeared on the cell membrane,the percentage of PI stained positive cells significantly increased(P＜0.05).OxLp(a)significantly inhibited the expression of mito-chondrial related proteins NRF1,NRF2 and PGC-1α,and the expression of mitochondrial gene CYTB,promoted an in-crease in mtROS generation,Ca2+overload,a decrease in ATP levels,a decrease in MMP,an increase in mPTP values,and abnormal mitochondrial morphology.After transfection with pHelper 2.0 lentivirus vector overexpressing CYTB,it was found that oxLp(a)induced HUVEC pyroptosis and mitochondrial morphological and functional abnormalities were par-tially reversed by overexpression of CYTB.Conclusion oxLp(a)promotes mitochondrial morphological and functional abnormalities and induces HUVEC pyroptosis by downregulating CYTB.

Objective:To investigate the effect of single nucleotide polymorphism (SNP) of FCN gene on the susceptibility of pre-eclampsia (PE) in Han nationality pregnant women.Methods:A total of 274 PE pregnant women (PE group) and 154 healthy pregnant women (control group) admitted to Boai Hospital of Zhongshan, Affiliated Hospital to Southern Medical University from October 2020 to October 2022 were collected. The general information, medical history, reproductive history, blood pressure, body mass index and blood biochemical indicators before delivery were compared between the two groups. Twenty-three SNP loci of FCN gene family were genotyped by time-of-flight mass spectrometry, and the serum levels of ficolins (ficolin-1, -2 and -3) were detected by enzyme-linked immunosorbent assay.Results:(1) Compared with the control group, the body mass index, mean arterial pressure, gestational age at delivery, blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase, direct bilirubin, albumin, and C-reactive protein in the PE group were significantly higher than those in the control group (all P<0.05). The levels of N-terminal pro-B type natriuretic peptide (NT-proBNP), placental growth factor (PlGF) and human soluble vascular endothelial growth factor receptor-1 (sFlt-1) were significantly different between the two groups (all P<0.05). (2) Among the 23 SNP loci in FCN gene family, 18 loci were in Hardy-Weinberg genetic equilibrium, including 5 loci in FCN1 gene, 10 loci in FCN2 gene, and 3 loci in FCN3 gene. Five loci that did not conform to Hardy-Weinberg genetic equilibrium were not included in the subsequent analysis. Compared with the control group, the genotype distribution of 3 loci of FCN2 gene (rs7872508, rs11103563, rs73664188) and 1 locus of FCN3 gene (rs3813800) in the PE group were significantly different (all P<0.05). After Bonferroni correction, only the genotype distribution of rs7872508 and rs73664188 in FCN2 gene were statistically different between the PE group and the control group (all P<0.05). Further analysis showed that for the rs7872508 locus of FCN2 gene, compared with GG genotype, genotype GT ( OR=3.025, 95% CI: 1.080-8.471) and TT ( OR=4.777, 95% CI: 1.758-12.979) both significantly increased the risk of PE (both P<0.05). For rs73664188 locus of FCN2 gene, compared with TT genotype, genotype TC ( OR=0.510, 95% CI: 0.334-0.778) significantly reduced the risk of PE ( P<0.05). (3) Compared with the control group, the serum levels of ficolin-1 and ficolin-2 in pregnant women in the PE group were significantly reduced (both P<0.05), while the level of ficolin-3 showed no significant change ( P=0.271). Correlation analysis showed that the serum levels of ficolin-2 in pregnant women in the PE group were significantly positively correlated with PlGF level ( r=0.321, P<0.001), and significantly negatively correlated with sFlt-1 level ( r=-0.187, P=0.002) and NT-proBNP level ( r=-0.392, P<0.001). Further analysis revealed that the serum levels of ficolin-2 in pregnant women of the PE group with GT and TT genotypes at rs7872508 locus of FCN2 gene were significantly reduced (both P<0.05), while the serum level of ficolin-2 in pregnant women of the PE group with TC genotype at the rs73664188 locus were significantly increased ( P<0.05). Conclusion:The SNP of FCN2 gene in FCN gene family might be related to the susceptibility to PE and have an effect on serum ficolin-2 level in PE pregnant women.