OBJECTIVE To establish a method for simultaneously determining three anti-tuberculosis drugs in the plasma of patients with spinal tuberculosis and apply it in clinical practice. METHODS LC-MS/MS method was established for the quantitative determination of the concentrations of isoniazid， rifampicin and pyrazinamide in the plasma of patients with spinal tuberculosis， using diphenhydramine as the internal standard. The determination was carried out using Chemalink CM-C18T column， with mobile phase consisting of 0.1% formic acid-methanol solution （gradient elution）， at the flow rate of 0.4 mL/min and an injection volume of 2 μL. Multiple reaction monitoring was conducted using an electrospray ionization source in positive ion mode. The ion pairs used for quantitative analysis were m/z 138.0→121.0（ for isoniazid）， m/z 823.3→791.3（ for rifampicin）， m/z 124.1→ 79.0 （for pyrazinamide）， and m/z 256.0→167.0 （for diphenhydramine）. Fifty-three patients diagnosed with spinal tuberculosis in Qinghai Provincial People’s Hospital from January 2023 to June 2025 were selected， and the plasma concentrations of isoniazid， rifampicin and pyrazinamide in these patients were measured using the above method. RESULTS The linear ranges for isoniazid， rifampicin and pyrazinamide were 0.5-16， 2-64， and 2.5-80 μg/mL， respectively （r≥0.998 7）. The accuracy ranged from 90.20% to 108.64% （n＝5）. RSDs for intra-day precision were all less than 6.63% （n＝5）， while those for inter-day precision were all less than 8.42% （n＝3）. The matrix effects ranged from 88.60% to 115.41% （n＝5）. The relative deviations in the stability tests were all within the ±15% range， and the carry-over effect did not interfere with the determination. The results of clinical application showed that the mean plasma drug concentrations of isoniazid， rifampicin and pyrazinamide in patients with spinal tuberculosis were （3.62±2.80）， （8.55±4.57）， and （20.12±6.56） μg/mL， respectively. The incidences of plasma drug concentrations falling below the effective peak concentrations were 49.06%， 58.49% and 60.38%， respectively. CONCLUSIONS The method established in this study is rapid， accurate， and demonstrates good stability， making it suitable for clinical monitoring of the plasma concentrations of isoniazid， rifampicin and pyrazinamide in patients with spinal tuberculosis.

Objective To evaluate the ability of contrast-enhanced ultrasound (CEUS) as a prognostic indicator of renal function in chronic kidney disease (CKD) patients.Methods A total of 122 patients with CKD were collected,and patients with allergies to sulfur hexafluoride,pregnancy,cardiopulmonary insufficiency,urinary calculus and tumour were excluded.These patients were divided into estimated glomerular filtration rate [eGFR,ml·min1· (1.73 m2)-1] ≥60 group,eGFR 30-59 group and eGFR ＜ 30 group.CEUS was performed after an intravenous bolus injection of 1.5 ml SonoVue (BR1;Bracco Milan,Italy).Time-intensity curves (TICs) and quantitative indexes were created using QLAB quantification software.Followed up for 2 years,and patients with eGFR dropped 50％,double serum creatinine and end-stage renal disease (ESRD) were regarded as having kidney failure events.Risk factors related to kidney survival were investigated using a multivariate Cox regression model.Results One hundred patients were enrolled in the study,with 78％ patients in CKD 1-2 stages,16％ in CKD 3 stage and 6％ in CKD 4-5 stages.Patients were followed for a mean period of 14.1 months,ten (10％) patients exhibited composite kidney failure events.Among 3 groups,significant differences in the left kidney length derived peak intensity (DPI) were noted (P=0.014,P=0.010).Multivariate Cox regression analysis revealed that the DPI was an independent factor of progression of kidney disease.Multiple linear regression showed that age,basic eGFR,peak intensity were associated with eGFR decline rate.Patients with DPI ＜ 12.27 db were less to recover from kidney disease progression as compared with patients with DPI≥ 12.27 db (P=0.008).The area under the curve (AUC) for DPI was 0.778(95％ CI 0.612-0.944,P＜ 0.05),with a sensitivity of 64％ and a specificity of 88％.Conclusions The DPI might be the most valuable CEUS parameter for the evaluation of renal function.The DPI could serve as an independent predictor of the long-term prognosis of CKD patients.