ObjectiveThis study aimed to establish a monocrotaline （MCT）-induced pulmonary arterial hypertension （PAH） rat model to systematically evaluate the protective effect of Xiao Qinglongtang （XQLT） on right cardiac function in model rats and further elucidate the underlying regulatory mechanism. MethodsSixty male SD rats were randomly assigned to the normal group， model group， XQLT low-， medium-， and high-dose groups （XQLT-L/M/H）， and the beraprost sodium tablet group （BST）. Except for the normal group， rats in all other groups were given a single subcutaneous injection of MCT （60 mg·kg^-1） to induce PAH. Three weeks after injection， rats in the XQLT-L/M/H groups were administered XQLT intragastrically at 3.07， 6.14， 12.28 g·kg^-1·d^-1， respectively. Rats in the BST group received beraprost sodium at 12.6 μg·kg^-1·d^-1， and rats in the model group received an equal volume of saline. All treatments lasted for 3 weeks. Right ventricular systolic pressure （RVSP） was measured by right ventricular catheterization. Cardiac function was assessed by echocardiography. The right ventricle was weighed to calculate the right ventricular hypertrophy index （RVHI）. Hematoxylin-eosin （HE） staining， Masson staining， and transmission electron microscopy were used to observe myocardial morphology. Serum metabolomic changes were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. Data-independent acquisition （DIA） proteomics was used to detect differentially expressed （DE） proteins in the right ventricle， and Western blot was used to measure the expression of uncoupling protein 3 （UCP3）， phosphatidylinositol 3-kinase catalytic subunit p110α （PIK3CA）， L1 cell adhesion molecule （L1CAM）， and quinone oxidoreductase （CRYZ）. UPLC-MS/MS was used to analyze the chemical components of XQLT. ResultsCompared with the normal group， the model group showed significantly increased RVSP and RVHI （P<0.05）， along with pathological changes in myocardial morphology. Compared with the model group， all XQLT-treated groups exhibited reductions in RVSP and RVHI as well as significant improvements in cardiac function and myocardial morphology. Among the XQLT groups， XQLT-M showed the most pronounced effects （P<0.05）， comparable to the BST group. Serum metabolomics revealed 105 differential metabolites in the XQLT groups versus the model group ［variable importance in projection （VIP） >1， P<0.05］， including 58 upregulated and 47 downregulated metabolites. KEGG enrichment analysis indicated that XQLT intervention downregulated phenylalanine metabolism （P<0.01） and upregulated unsaturated fatty acid biosynthesis （P<0.05）. Proteomics analysis showed that 982 DE proteins were identified in the MCT groups versus the normal group， including 455 upregulated and 527 downregulated proteins （|fold change （FC）| >1.3， P<0.05）. Compared with the model group， 237 DE proteins were identified in the XQLT groups， including 124 upregulated and 113 downregulated proteins （|FC| >1.3， P<0.05）， with 57 overlapping DE proteins. KEGG enrichment suggested that XQLT mainly modulated pathways related to mineral absorption， ribosomal biogenesis， peroxisomes， glycolysis/gluconeogenesis， spliceosomes， and thyroid hormone signaling. Western blot analysis showed that， compared with the model group， XQLT increased the expression of UCP3， PIK3CA， and L1CAM， while decreasing the expression of CRYZ （P<0.05）. ConclusionXQLT exerts a protective effect on right heart function in MCT-induced PAH rats， and its mechanism is associated with maintaining myocardial homeostasis and alleviating right ventricular remodeling.

Objective To investigate the current status of cognitive impairment and its influencing factors in patients with Alzheimer's disease (AD) and to explore effective intervention strategies. Methods A total of 380 patients with AD diagnosed in the Qingdao Central Hospital were retrospectively enrolled between January 2023 and January 2025. According to scores of Montreal Cognitive Assessment (MoCA), the patients were divided into a mild cognitive impairment group (21-25 points) and a moderate to severe impairment group (<21 points). The general clinical data in the two groups were collected. The influencing factors of moderate to severe cognitive impairment were analyzed by univariate and multivariate logistic regression analysis. Results Among the 380 AD patients, 157 cases (41.32%) had mild cognitive impairment, and 223 cases (58.68%) had moderate to severe cognitive impairment. Compared with the mild cognitive impairment group, the moderate to severe cognitive impairment group had a higher proportion of patients who were aged ≥ 75 years, engaged in physical labor, had a disease course of ≥5 years, and had moderate to severe atrophy on head CT examination (P < 0.05). Age ≥75 years, disease course ≥5 years, and moderate to severe atrophy on head CT were independent risk factors of moderate to severe cognitive impairment in AD patients (P<0.05). Conclusion Cognitive impairment is closely related to age, disease course and head CT manifestations in AD patients. Interventions targeting these key factors are expected to delay cognitive decline and improve patients' quality of life.

Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy. Approximately 50% to 60% of patients with OSCC are diagnosed at a locally advanced stage (clinical staging III-IVa). Even with comprehensive and sequential treatment primarily based on surgery, the 5-year overall survival rate remains below 50%, and patients often suffer from postoperative functional impairments such as difficulties with speaking and swallowing. Programmed death receptor-1 (PD-1) inhibitors are increasingly used in the neoadjuvant treatment of locally advanced OSCC and have shown encouraging efficacy. However, clinical practice still faces key challenges, including the definition of indications, optimization of combination regimens, and standards for efficacy evaluation. Based on the latest research advances worldwide and the clinical experience of the expert group, this expert consensus systematically evaluates the application of PD-1 inhibitors in the neoadjuvant treatment of locally advanced OSCC, covering combination strategies, treatment cycles and surgical timing, efficacy assessment, use of biomarkers, management of special populations and immune related adverse events, principles for immunotherapy rechallenge, and function preservation strategies. After multiple rounds of panel discussion and through anonymous voting using the Delphi method, the following consensus statements have been formulated: 1) Neoadjuvant therapy with PD-1 inhibitors can be used preoperatively in patients with locally advanced OSCC. The preferred regimen is a PD-1 inhibitor combined with platinum based chemotherapy, administered for 2-3 cycles. 2) During the efficacy evaluation of neoadjuvant therapy, radiographic assessment should follow the dual criteria of Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and immune RECIST (iRECIST). After surgery, systematic pathological evaluation of both the primary lesion and regional lymph nodes is required. For combination chemotherapy regimens, PD-L1 expression and combined positive score need not be used as mandatory inclusion or exclusion criteria. 3) For special populations such as the elderly (≥ 70 years), individuals with stable HIV viral load, and carriers of chronic HBV/HCV, PD-1 inhibitors may be used cautiously under the guidance of a multidisciplinary team (MDT), with close monitoring for adverse events. 4) For patients with a poor response to neoadjuvant therapy, continuation of the original treatment regimen is not recommended; the subsequent treatment plan should be adjusted promptly after MDT assessment. Organ transplant recipients and patients with active autoimmune diseases are not recommended to receive neoadjuvant PD-1 inhibitor therapy due to the high risk of immune related activation. Rechallenge is generally not advised for patients who have experienced high risk immune related adverse events such as immune mediated myocarditis, neurotoxicity, or pneumonitis. 5) For patients with a good pathological response, individualized de escalation surgery and function preservation strategies can be explored. This consensus aims to promote the standardized, safe, and precise application of neoadjuvant PD-1 inhibitor strategies in the management of locally advanced OSCC patients.

Background/Aims: Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy. Methods: We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues. Results: We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts. Conclusion Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.

ObjectiveTo explore the mechanisms of Salviae Miltiorrhizae Radix et Rhizoma in treating metabolic hypertension induced by a high-sugar and high-fat diet in rats based on network pharmacology， proteomics， and animal experiments. MethodsThirty male SD rats were randomized into the control， model， positive drug （tetrandrine， Tet， 50 mg·kg^-1·d^-1）， low-dose Salviae Miltiorrhizae Radix et Rhizoma （DS-L， 45×10⁴ mg·kg^-1·d^-1）， and high-dose Salviae Miltiorrhizae Radix et Rhizoma （DS-H， 90×10⁴ mg·kg^-1·d^-1） groups. Except for the control group， each group was fed a high-fat and high-sugar diet for 8 weeks for the modeling of metabolic hypertension. Following successful modeling， drug interventions were conducted through gavage for 4 weeks. Blood pressure and lipid indicators were monitored， and cardiac function was assessed via echocardiography. Samples from the thoracic aorta and cardiac tissue were collected for histopathological examination. Network pharmacology analysis identified key active components， potential targets， and mechanisms of Salviae Miltiorrhizae Radix et Rhizoma in treating hypertension. Proteomics technology was employed to analyze the differential proteins and major pathway targets to synergistically elucidate the antihypertensive mechanism of Salviae Miltiorrhizae Radix et Rhizoma. Ca²⁺ concentrations in the thoracic aorta and cardiac tissue were measured. The protein levels of transient receptor potential cation channel （TRPC）3， TRPC6， NADPH oxidase （NOX）2， and NOX4 were quantified via Western blotting. The levels of oxidative stress markers and inflammatory factors， including superoxide dismutase （SOD）， malondialdehyde （MDA）， tumor necrosis factor-α （TNF-α）， and interleukin-1β （IL-1β）， were determined by enzyme-linked immunosorbent assay （ELISA）. Molecular docking analysis was performed for the main components of Salviae Miltiorrhizae Radix et Rhizoma with TRPC3， TRPC6， NOX2， and NOX4. ResultsThe experimental results indicated that compared with the control group， the model group exhibited abnormally elevated blood pressure and increased lipid levels （P<0.01）. Compared with the model group， the DS-L group exhibited reduced systolic blood pressure （SBP）， diastolic blood pressure （DBP）， and mean arterial pressure （MAP） （P<0.05）， decreased serum levels of triglycerides （TG）， total cholesterol （TC）， and low-density lipoprotein cholesterol （LDL-C） （P<0.05）， and increased level of high-density lipoprotein cholesterol （HDL-C） （P<0.01）. The DS-H and Tet groups showed more significant effects （P<0.01）. Moreover， the interventions attenuated vascular wall thickening， myocardial cell injury， and collagen and lipid deposition. Network pharmacology and proteomics prediction results indicated that the core targets of Salviae Miltiorrhizae Radix et Rhizoma in treating hypertension were TRPC3， TRPC6， NOX2， and NOX4， and the core pathways included calcium signaling， cyclic guanosine monophosphate （cGMP）/cGMP-dependent protein kinase （PKG） signaling， and atherosclerosis-related pathways. The molecular mechanism experiment results indicated that compared with the control group， the model group exhibited significantly elevated tissue Ca²⁺ concentrations， exacerbated oxidative stress and inflammatory responses， and upregulated protein levels of TRPC3， TRPC6， NOX2， and NOX4 in the thoracic aorta and myocardial tissue （P<0.01）. Compared with the model group， DS-L reduced the free Ca²⁺ concentration， lowered the levels of IL-1β， TNF-α， SOD， and MDA （P<0.05）， and downregulated the protein levels of TRPC3， TRPC6， NOX2， and NOX4 in the thoracic aorta and myocardial tissue （P<0.05）. DS-H and Tet exhibited more significant effects （P<0.01）. Meanwhile， the main components of Salviae Miltiorrhizae Radix et Rhizoma had strong binding affinity with the core targets of hypertension. ConclusionSalviae Miltiorrhizae Radix et Rhizoma may ameliorate oxidative stress and mitigate inflammatory responses by regulating the TRPC3/6/NOX2/4 signaling pathway， thereby alleviating abnormal blood pressure abnormality and myocardial injury in hypertensive rats.

ObjectiveTo investigate the accuracy of multiple discriminant analysis （MDA） versus fibrosis-4 （FIB-4） in assessing liver fibrosis degree in patients with HBV infection， as well as the possibility of MDA as an indicator for disease progression. MethodsA total of 263 patients with HBV infection who underwent liver biopsy in The First Affiliated Hospital of Guangxi Medical University from April 2010 to April 2024 were included， and their clinical data were collected. According to the results of pathological examination， they were divided into non-significant fibrosis group （F<2） with 126 patients and significant fibrosis group （F≥2） with 137 patients. The correlation of MDA and FIB-4 with liver fibrosis degree was analyzed， and MDA and FIB-4 were compared in terms of their accuracy in assessing significant liver fibrosis. A total of 62 patients completed follow-up， and according to the presence or absence of progression to liver cirrhosis at the last follow-up visit， they were divided into progressive group with 21 patients and non-progressive group with 41 patients； the efficacy of MDA and FIB-4 in diagnosing disease progression was analyzed and compared. The independent-samples t test was used for comparison of normally distributed continuous data between groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups； the Kruskal-Wallis H test was used for comparison between multiple groups， and the Bonferroni method was used for further comparison between two groups. The chi-square test was used for comparison of categorical data. The Spearman’s correlation coefficient was used for correlation analysis. The Wilcoxon signed rank sum test was used for the analysis of baseline data and data at the end of follow-up， and the binary Logistic regression analysis was used to investigate the influencing factors for progression to liver cirrhosis. The receiver operating characteristic （ROC） curve was used to investigate the diagnostic efficacy of indicators， the Z-test was used for comparison of the area under the ROC curve （AUC）， and the paired chi-square test was used for comparison of the sensitivity， specificity， and accuracy of the two indicators. ResultsThe correlation coefficient between FIB-4 and liver fibrosis degree was 0.378， while the correlation coefficient between MDA and liver fibrosis degree was -0.325 （both P<0.001）. FIB-4 had an AUC of 0.688， a sensitivity of 64.96%， a specificity of 68.87%， a positive predictive value of 67.42%， a negative predictive value of 63.36%， an accuracy of 65.40%， and a cut-off value of 1.01， while MDA had an AUC of 0.653， a sensitivity of 52.55%， a specificity of 78.57%， a positive predictive value of 72.73%， a negative predictive value of 60.37%， an accuracy of 65.02%， and a cut-off value of 0.29， suggesting that compared with FIB-4， MDA had a lower sensitivity （P=0.004） and a higher specificity （P=0.001）. The progressive group had a significantly higher age than the non-progressive group at baseline （t=2.611， P=0.011）. For the progressive group， there was an increase in FIB-4 and a reduction in MDA from baseline to the end of follow-up （both P<0.001）， while the non-progressive group showed no significant changes （both P>0.05）. The multivariate Logistic regression analysis showed that aspartate aminotransferase （odds ratio ［OR］=0.940， 95% confidence interval ［CI］： 0.885‍ ‍—‍ ‍0.998， P<0.05） and MDA （OR=0.445， 95%CI： 0.279‍ ‍—‍ ‍0.710， P<0.001） were independent influencing factors for disease progression. MDA had an AUC of 0.893 and an optimal cut-off value of -0.01 in diagnosing the disease progression of liver cirrhosis. ConclusionMDA has a comparable accuracy to FIB-4 in the diagnosis of significant liver fibrosis， and MDA<-0.01 has a high accuracy in diagnosing the progression of liver fibrosis to liver cirrhosis， which can help to reduce the need for liver biopsy in clinical practice.

BACKGROUND:Studies have shown that patients with premature ovarian failure have changes in the structure of intestinal flora and that imbalance of intestinal microbiota may be one of the important mechanisms in the development of premature ovarian failure. OBJECTIVE:To investigate the effect of Liuwei Dihuang Wan on oxidative stress and intestinal microbiota in premature ovarian failure mice induced by cyclophosphamide. METHODS:Forty-five female ICR mice were randomized into three groups:blank group(normal mice),model group(premature ovarian failure mice),and Liuwei Dihuang Wan group.A mouse model of premature ovarian failure was prepared by one-time intraperitoneal injection of cyclophosphamide(120 mg/kg)in the latter two groups.After successful modeling,the Liuwei Dihuang Wan group was intragastrically administered for 28 continuous days,and the other two groups were intragastrically administered with the same amount of normal saline for 28 days.Mouse body mass was recorded weekly and ovarian index was calculated.The development of mouse follicles was observed using hematoxylin-eosin staining.ELISA method was used to detect serum levels of anti-Mullerian hormone,estradiol,follicle stimulating hormone,superoxide dismutase,glutathione peroxidase,and malondialdehyde.Meanwhile,the gut microbiome of all mice was detected through 16S rDNA sequencing. RESULTS AND CONCLUSION:The mice in the model group had loose hair,decreased vigor and grip strength,almost no increase in body mass,and decreased ovarian index.Whereas,the mouse body mass and ovarian index were increased after treatment with Liuwei Dihuang Wan(P<0.05).The estrous cycle of mice in the model group was disorganized;Liuwei Dihuang Wan could restore the estrous cycle and reduce the number of atretic follicles in mice with premature ovarian failure.The serum levels of follicle stimulating hormone and malondialdehyde in the model group significantly increased(P<0.01),while the levels of estradiol,anti-Mullerian hormone,superoxide dismutase,and glutathione peroxidase significantly decreased(P<0.01).Liuwei Dihuang Wan could significantly decrease the serum levels of follicle stimulating hormone and malondialdehyde(P<0.01),and increase the levels of estradiol,anti-Mullerian hormone,superoxide dismutase,and glutathione peroxidase.According to the 16S rDNA sequencing results,Liuwei Dihuang Wan could regulate the abundance and diversity of intestinal microbiota,and increase the relative abundance of beneficial bacteria.KEGG pathway analysis showed that the intestinal microbiota and metabolic pathways,biosynthesis of secondary metabolites,microbial metabolism in different environments,and biosynthesis of amino acids were regulated by Liuwei Dihuang Wan.To conclude,the changes in the structure of intestinal microbiome may be one of the potential mechanisms of Liuwei Dihuang Wan in treating premature ovarian failure.Liuwei Dihuang Wan can regulate the structure of intestinal microbiome,increase the number of beneficial bacteria,reduce the number of harmful bacteria,and thus improve the balance of intestinal microbiota.This regulatory effect helps to reduce oxidative stress levels and further inhibit ovarian oxidative stress in mice with premature ovarian failure.

OBJECTIVE: To investigate the effectiveness of Xuanshen Yishen Decoction (XYD) in the treatment of hypertension. METHODS: Hospital electronic medical records from 2019-2023 were utilized to emulate a randomized pragmatic clinical trial. Hypertensive participants were eligible if they were aged ⩾40 years with baseline systolic blood pressure (BP) ⩾140 mm Hg. Patients treated with XYD plus antihypertensive regimen were assigned to the treatment group, whereas those who followed only antihypertensive regimen were assigned to the control group. The primary outcome assessed was the attainment rate of intensive BP control at discharge, with the secondary outcome focusing on the 6-month all-cause readmission rate. RESULTS: The study included 3,302 patients, comprising 2,943 individuals in the control group and 359 in the treatment group. Compared with the control group, a higher proportion in the treatment group achieved the target BP for intensive BP control [8.09% vs. 17.5%; odds ratio (OR)=2.29, 95% confidence interval (CI)=1.68 to 3.13; P<0.001], particularly in individuals with high homocysteine levels (OR=3.13; 95% CI=1.72 to 5.71; P<0.001; P for interaction=0.041). Furthermore, the 6-month all-cause readmission rate in the treatment group was lower than in the control group (hazard ratio=0.58; 95% CI=0.36 to 0.91; P=0.019), and the robustness of the results was confirmed by sensitivity analyse. CONCLUSIONS XYD could be a complementary therapy for intensive BP control. Our study offers real-world evidence and guides the choice of complementary and alternative therapies. (Registration No. ChiCTR2400086589).
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Antihypertensive Agents/pharmacology* ; Blood Pressure/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Hypertension/physiopathology* ; Patient Readmission ; Treatment Outcome

OBJECTIVE: To evaluate the efficacy and safety of Shexiang Tongxin Dropping Pill (STDP) in treating stable angina patients with phlegm-heat and blood-stasis syndrome by exercise duration and metabolic equivalents. METHODS: This multicenter, randomized, double-blind, placebo-controlled clinical trial enrolled stable angina patients with phlegm-heat and blood-stasis syndrome from 22 hospitals. They were randomized 1:1 to STDP (35 mg/pill, 6 pills per day) or placebo for 56 days. The primary outcome was the exercise duration and metabolic equivalents (METs) assessed by the standard Bruce exercise treadmill test after 56 days of treatment. The secondary outcomes included the total angina symptom score, Chinese medicine (CM) symptom scores, Seattle Angina Questionnaire (SAQ) scores, changes in ST-T on electrocardiogram and adverse events (AEs). RESULTS: This trial enrolled 309 patients, including 155 and 154 in the STDP and placebo groups, respectively. STDP significantly prolonged exercise duration with an increase of 51.0 s, compared to a decrease of 12.0 s with placebo (change rate: -11.1% vs. 3.2%, P<0.01). The increase in METs was significantly greater in the STDP group than in the placebo group (change: -0.4 vs. 0.0, change rate: -5.0% vs. 0.0%, P<0.01). The improvement of total angina symptom scores (25.0% vs. 0.0%), CM symptom scores (38.7% vs. 11.8%), reduction of nitroglycerin consumption (100.0% vs. 11.3%), and all domains of SAQ, were significantly greater with STDP than placebo (all P<0.01). The changes in Q-T intervals at 28 and 56 days from baseline were similar between the two groups (both P>0.05). Twenty-five participants (16.3%) with STDP and 16 (10.5%) with placebo experienced AEs (P=0.131), with no serious AEs observed. CONCLUSION STDP could improve exercise tolerance in patients with stable angina and phlegm-heat and blood stasis syndrome, with a favorable safety profile. (Registration No. ChiCTR-IPR-15006020).
Humans ; Double-Blind Method ; Drugs, Chinese Herbal/adverse effects* ; Male ; Female ; Middle Aged ; Angina, Stable/physiopathology* ; Aged ; Syndrome ; Treatment Outcome ; Placebos ; Tablets

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